We report a patient with a severe limitation of function in the right hand resulting from grasp reflex following a stroke affecting the left anterior cerebral artery region. We describe, using diffusion tensor tractography (DTT), a disconnection between the bilateral frontal lobes via the corpus callosum. The patient could not control his right hand at all, even though his bilateral corticospinal tracts were intact. We noted that over the infarcted lesion on DTT, the white matter was invisible from the corpus callosum to the prefrontal cortex. These findings reflected a unique pattern of white-matter disconnection between the ipsilateral medial frontal lobe and ipsilateral and contralateral frontal cortex causing hand function deterioration in the form of severe grasp reflex.
Citations
To investigate the electrophysiological effects of focal vibration on the tendon and muscle belly in healthy people.
The miniaturized focal vibrator consisted of an unbalanced mass rotating offset and wireless controller. The parameters of vibratory stimulation were adjusted on a flat rigid surface as 65 µm at 70 Hz. Two consecutive tests on the different vibration sites were conducted in 10 healthy volunteers (test 1, the Achilles tendon; test 2, the muscle belly on the medial head of the gastrocnemius). The Hoffman (H)-reflex was measured 7 times during each test. The minimal H-reflex latency, maximal amplitude of H-reflex (Hmax), and maximal amplitude of the M-response (Mmax) were acquired. The ratio of Hmax and Mmax (HMR) and the vibratory inhibition index (VII: the ratio of the Hmax after vibration and Hmax before vibration) were calculated. The changes in parameters according to the time and site of stimulation were analyzed using the generalized estimating equation methods.
All subjects completed the two tests without serious adverse effects. The minimal H-reflex latency did not show significant changes over time (Wald test: χ2=11.62, p=0.07), and between the two sites (χ2=0.42, p=0.52). The changes in Hmax (χ2=53.74, p<0.01), HMR (χ2=20.49, p<0.01), and VII (χ2=13.16, p=0.02) were significant over time with the adjustment of sites. These parameters were reduced at all time points compared to the baseline, but the decrements reverted instantly after the cessation of stimulation. When adjusted over time, a 1.99-mV decrease in the Hmax (χ2=4.02, p=0.04) and a 9.02% decrease in the VII (χ2=4.54, p=0.03) were observed when the muscle belly was vibrated compared to the tendon.
The differential electrophysiological effects of focal vibration were verified. The muscle belly may be the more effective site for reducing the H-reflex compared to the tendon. This study provides the neurophysiological basis for a selective and safe rehabilitation program for spasticity management with focal vibration.
Citations
To establish a correlation between the modified Ashworth scale (MAS) and amplitude and latency of T-reflex and to demonstrate inter-rater and intra-rater reliability of the T-reflex of the biceps muscle for assessing spasticity after stroke.
A total of 21 patients with hemiplegia and spasticity after ischemic stroke were enrolled for this study. The spasticity of biceps muscle was evaluated by an occupational therapist using the MAS. The mean value of manual muscle test of biceps muscles was 2.3±0.79. Latency and amplitude of T-reflex were recorded from biceps muscles by two physicians. The onset latency and peak to peak amplitude of the mean of 5 big T-reflex were measured. The examinations were carried out by two physicians at the same time to evaluate the inter-rater reliability. Further, one of the physicians performed the examination again after one week to evaluate the intra-rater reliability. The correlations between MAS and T-reflex, and the intra- and inter-rater reliability of biceps T-reflex were established by calculating the Spearman correlation coefficients and the intra-class correlation coefficients (ICCs).
Amplitude of the biceps T-reflex increased with increasing level of MAS (
Biceps T-reflex demonstrates a good quantitative measurement and correlation tool with MAS for spasticity, and also shows acceptable inter- and intra-rater reliability, which can be used for patients with spasticity after stroke.
Citations
To evaluate the spasticity and electrophysiologic effects of applying extracorporeal shock wave therapy (ESWT) to the gastrocnemius by studying F wave and H-reflex.
Ten healthy adults and 10 hemiplegic stroke patients with ankle plantarflexor spasticity received one session of ESWT on the medial head of the gastrocnemius. The modified Ashworth scale (MAS), tibial nerve conduction, F wave, and H-reflex results were measured before and immediately after the treatment. The Visual Analogue Scale (VAS) was used during ESWT to measure the side effects, such as pain.
There were no significant effects of ESWT on the conduction velocity, distal latency and amplitude of tibial nerve conduction, minimal latency of tibial nerve F wave, latency, or H-M ratio of H-reflex in either the healthy or stroke group. However, the MAS of plantarflexor was significantly reduced from 2.67±1.15 to 1.22±1.03 (p<0.05) after applying ESWT in the stroke group.
After applying ESWT on the gastrocnemius in stroke patients, the spasticity of the ankle plantarflexor was significantly improved, with no changes of F wave or H-reflex parameters. Further studies are needed to evaluate the mechanisms of the antispastic effect of ESWT.
Citations
To evaluate normal healthy persons without spasticity to observe normal findings of the elbow stretch reflex using a newly developed, portable, hand-driven spasticity-measuring system.
Thirty normal persons without any disease involving the central or peripheral nervous system were enrolled in this study. The portable hand-driven isokinetic system is able to measure the joint angle, angular velocity, electromyographic (EMG) signals, and torque during elbow passive extension-flexion. One set of 10 passive elbow extension and flexion movements was performed for data acquisition at each angular velocity, including 60, 90, 120, 150 and 180 degrees per second (°/sec). Electromyographic data were collected from the biceps brachii and the triceps brachii. Torque data were collected from sensors around the wrist.
We were able to detect EMG activity and torque in all subjects by using the new portable hand-driven isokinetic system. EMG activity and torque increased with incremental increase of angular velocities. The joint angle of maximal EMG activity according to different angular velocities did not show any significant difference (116°-127° in elbow extension and 37°-66° in elbow flexion). The joint angles of maximal torque according to different angular velocities were not significantly different either.
Using the portable hand-driven isokinetic system on the elbows of normal subjects, we were able to obtain expected results. By considering our normal findings of the elbow stretch reflex using this system, we propose that the various aspects of spasticity-related data can be measured successfully.
Citations
Objective: The aim of this study was to develop objective evaluation method which reflect the velocity dependent increase of stretch reflex in spasticity using the pendulum test and dynamic electromyography.
Method: Kinematic analysis for knee angle and angular velocity measurement, and dynamic electromyography were performed simultaneously during pendulum movement of spastic lower extremity in supine position for nineteen spastic hemiplegia patients and ten normal control subjects. Angular relaxation index (ARI), Maximum angular velocity (MAV), Angular threshold (AT) and Angular velocity threshold (AVT) were used for the evaluation of spsticity.
Results: 1) ARI was 1.64⁑0.04 in normal, 1.28⁑0.14 in modified Ashworth scale (MAS) I, 1.18⁑0.16 in MAS II, 1.02⁑0.13 in MAS III, 2) MAV was 325.0⁑29.4 in normal, 301.7⁑37.8 in MAS I, 269.2⁑29.7 in MAS II, 232.4⁑28.2 in MAS III, 3) In normal subjects EMG activity did not occur, whereas in spastic hemiplegic patient a stretch reflex appears in thigh muscle. AT and AVT were 57.39⁑4.45, 256.24⁑14.07 in MAS I, 38.59⁑4.26, 184.45⁑12.7 in MAS II, 19.13⁑7.13, 136.06⁑12.88 in MAS III, respectively, 4) Correlation coefficients of the ARI (r=0.786), AT (r=0.960), AVT (r=0.949) showed significantly negative correlations with the MAS.
Conclusion: 1) AT and AVT are more sensitive parameters than ARI for documenting spasticity in hemiplegic patients. 2) An evaluation of spasticity using pendulum test and dynamic electromyography would provide consistent results with little error and would not be influenced by the change of examiner or environment. Thus we can get very reliable results using this method.
Objective: There has been some existing problems with the electrical reflex hammer. The occurrence of pressure build up with percussion and change of hammering points is one example. In order to make improvements on this device, we conducted studies with a newly designed percussion instrumental stimulator.
Method: The data collected from the first group was based on the manual percussion of electrical reflex hammer on the patella ligament. The data collected from the second group by usage of a newly designed instrumental stimulator maintained steady pressure and time and target position on the electrical reflex hammer. Comparisons were made between the two group.
Results: Our single measure of latency and amplitude on the manual and instrumental percussion group resulted in the reliability of 84.67%, 91.23%, 73.63%, and 83.29%. The 10 repeated measure of latency and amplitude on the manual and instrumental percussion group resulted in the reliability of 99.95%, 99.97%, 99.90%, and 99.94%.
Conclusion: From our experiment on the tendon reflex, we found out that it is important to have an instrumental stimulator that can maintain steady pressure while it is applying percussion to accurate data. On manual percussion, it is important to obtain data based on mean value of repeated measurements.
Many factors have been identified which to affect the rate of propagation of impulses along motor fibers. These include temperature changes around the nerve, diameter of the axon, degree of myelinization, age of infants, and local environment of the nerve. Motor nerve conduction velocity and Hoffman's reflex latency have been used to assess the degree of myelination and maturation of the nervous system. The conduction velocities in infants of a short gestational age are significantly lower than those of the fullterm infants. The extrauterine myelination and maturation might increase nerve conduction velocity. We measure the median motor nerve conduction velocity, compound muscle action potentials amplitude and H-reflex latency of premature infants to determine the neurological maturation after birth. The premature infants with gestational age above 37 weeks have a significantly higher conduction velocity and a shorter H-reflex latency than those of gestational age below 37 weeks. The premature infants with weight over 2.5 kg have a significantly higher conduction velocity, larger compound muscle action potentials amplitude and a shorter H-reflex latency than those of weight below 2.5 kg. And there is a statistically significant negative correlation of the H-reflex latency with the postmenstrual age. The determination of motor nerve conduction velocities and H-reflex latencies seem to be an additional method in assessing the degree of maturity in infants after birth.
Objective: To evaluate the change of abnormal spontaneous activities according to the clinical and radiologic findings, and to the time course after onset in hemiplegic upper limb.
Method: We scored abnormal spontaneous activities of hemiplegic upper limb muscles (infraspinatus, deltoid, extensor carpi radialis, abductor pollicis brevis, abductor digiti minimi) in 100 hemiplegic patients without peripheral neuropathy. The abnormal spontaneous activities were evaluated according to their radiologic findings and to Brunnstrom stage and the presence of reflex sympathetic dystrophy (RSD), and the time course after the onset (A cross-sectional study). In addition we repeatedly examined 40 hemiplegic patients until 12 weeks after the onset to define the pattern of change (A prospective study).
Results: There was no significant difference in the score of abnormal spontaneous activities according to the radiologic findings. The score of abnormal spontaneous activities decreased while Brunnstrom stage progressed. In both the cross-sectional and prospective studies, we found that the abnormal spontaneous activities decreased according to the time course after the onset in the limb without RSD, but sustained in the limb with RSD.
Conclusion: Abnormal spontaneous activities decreased according to the progression of Brunnstrom stages. The hemiplegic patients with RSD showed more profuse and sustained abnormal spontaneous activities at needle EMG study of hemiplegic upper limb than the patients without RSD.
Objective: The purpose of this study was to analyse the myotatic reflex characteristics of children with spastic cerebral palsy compared with normal infants and children
Method: Thirty four children with spastic cerebral palsy and 42 normal children were examined. The tendon taps were applied to the patellar and Achilles' tendons and shin using an electric reflex hammer. Compound muscle action potentials (CMAPs) were recorded from hamstring (HAM), rectus femoris (RF), tibialis anterior (TA), and gastrocnemias (GCL) by surface electrodes. The response ratios of HAMs/RF and TA/GCL were determined from CMAP amplitude.
Results: The mean HAM/RF ratios after patellar taps were 0.32⁑0.33, 0.37⁑0.33 and 0.32⁑0.19 in children with cerebral palsy, normal infants, and children over 1 year of age, respectively. The mean TA/GCL ratios following Achilles tap were 0.40⁑0.30, 0.93⁑0.11, and 0.25⁑0.14 in children with cerebral palsy, normal infants, and children over 1 year of age, respectively. All the spastic cerebral palsy children showed muscle responses in RF, HAM, TA and GCL after shin tap, but normal children did not.
Conclusion: The results reflect that the reflex responses are exaggerated in children with spastic cerebral palsy, and it can be used in the early diagnosis of cerebral palsy.
Objective: To investigate the immediate effect of dorsal penile nerve (DPN) stimulation on detrusor pressure (Pdet) and blood pressure (BP) during hyper-reflexic contractions of the bladder in patients with cervical spinal cord injury (SCI).
Method: The subjects were eight male patients with cervical SCI who had symptoms of autonomic dysreflexia. During water-cystometry, BP was monitored using an intra-arterial catheter into the radial artery, and was recorded simultaneously with the Pdet. Electrical stimulation was applied to the DPN, using surface electrodes each time a bladder contraction was detected. Baseline BP and BP at the first and the last hyper-reflexic contractions of bladder were measured with Pdet, respectively.
Results: As Pdet increased, the BP increased in all cases. The reflex contractions of the bladder were effectively suppressed by DPN stimulation, and as the Pdet decreased during stimulation, radial arterial pressure also decreased immediately and significantly.
Conclusion: DPN stimulation can lower both Pdet and the elevated BP. (J Korean Acad Rehab Med 2002; 26: 409- 413)
In a previous study, the authors have suggested that there is a central mechanism in pain modulation of TENS, and interferential current therapy(ICT) by using the tail-flick reflex and measuring the cerebrospinal fluid Ղ-endorphin of the rat. To confirm this central opiate-mediated pain modulation, we examined the reversal of a delayed tail-flick reflex latency and the cerebrospinal fluid Ղ-endorphin level by the naloxone administration. We measured the latencies of fictive tail-flick reflex before, immediately after TENS, ICT, and 15 minutes after naloxone administration. Cerebrospinal fluid Ղ-endorphin was also measured quantitatively by radioimmunoassay after TENS, ICT and naloxone administration.
The results revealed that in the group with TENS application, the latency of tail flick reflex after naloxone administration(31.54⁑5.08) was reversed to the level before the TENS application(34.76⁑6.09 msec) compared to the level after the TENS application(were 42.28⁑10.14 msec). With ICT application, the latency of tail flick reflex after naloxone administration(32.46⁑5.52msec) was also reversed to the level before the ICT (33.39⁑4.72 msec) application compared to the level immediately after the ICT application(46.87⁑10.14 msec). The Ղ-endorphin levels in cerebrospinal fluid were significantly decreased in the groups of naloxone administration, both with the TENS(14.86⁑3.92 pmol/l) and the ICT applications(18.04⁑3.93 pmol/l) compared to the control group(52.05⁑14.12 pmol/l).
We confirmed that the central pain modulation mechanism of TENS and ICT was through the reversal of delayed tail-flick reflex latency and elevated CSF β-endorphin level after naloxone administration
Objective: To study the changes of magnetic evoked potentials by thinking of simple motion without actual muscle action of that motion.
Method: We use H-reflex to test the excitability of relevant pools of spinal motor neurons and Magnetic Evoked Potentials (MEPs) to study the core of brain motor activity. The H-reflex and MEPs were obtained in three different conditions. 1) non-facilitation (NF), that is, resting state without actual motion and without thinking of that motion. 2) volitional-faciliation (VF), with actual motion which is usual manner of facilitation of MEPs. 3) thinking-facilitation (TF), without actual motion but with imaginary thinking of that motion. We evaluate the thresholds, amplitudes and latencies of H-reflex and MEPs in each three condition.
Results: Comparing with the parameters in NF condition as a baseline, there were no significant changes in any parameters of H-reflex in TF condition, but there were significant changes in threshold and amplitude of H-reflex in VF. On the while there were significant changes both in VF and TF of MEPs. The amount of facilitation of MEPs were greater in VF than in TF; the amount threshold decrement, amplitude increment and latency decrement of MEPs were greater in VF than in TF.
Conclusion: Thinking of simple motion without actual muscle action of that motion could facilitate the MEPs, and this facilitation is induced by increasing activity of brain motor cortex not by that of spinal cord level.
The study of blink reflexes was carried out to demonstrate the correlations, if there were, between the stage of diffuse axonal injury(DAI) and the abnormality of blink reflexes. The blink reflex was recorded in 20 healthy adult subjects and 22 patients with DAI who were classified according to Adams' classification(DAI I; 7, DAI II; 9 and DAI III; 6). The latencies and amplitudes of R1 and R2 in patients with DAI were compared with those of healthy subjects.
The results were as follows; 1) In 20 subjects of patient group, the latencies of R1 were all within a normal range. In 2 subjects, the difference in latencies between the two sides was above 1.4 msec. 2) In 15 subjects, R2 was absent or delayed, and reduced in the size of amplitude in all. Nine were affected bilaterally, and 4 were unilaterally. 3) Seventy one percent of patients in each stage represented abnormal findings. 4) There were no correlations between the DAI stage and the blink reflex.
This study demonstrated that the polysynaptic R2 was more profoundly suppressed than the oligosynaptic R1 in a diffuse axonal injury because of a loss or decrease of suprapontine facillitation, which influenced the trigeminal spinal complex and the interneuron of lateral reticular formation.
Objective: The purpose of this study was to establish the normal values of tendon reflexes (T-reflex) in upper extremities of normal Korean adults.
Method: T-reflex responses were recorded in 30 normal volunteers by delivering tendon taps with a hand operated electric reflex hammer. From 5 repeated trials of each subject, the shortest onset latency and duration, the largest peak to peak amplitude of compound muscle action potentials were chosen for representative values.
Results:
1) There was no significance in the side-to-side differences for all values.
2) Mean values of latency were 13.8⁑1.1 msec in males, 12.4⁑0.9 msec in females for biceps T-reflex and 13.0⁑1.1 msec in males, 11.3⁑1.0 msec in females for triceps T-reflex and there were significant differences between males and females.
3) Height and upper arm length showed a significant positive correlation with biceps and triceps T-reflex latency (p＜0.001).
Conclusion: We believe that our results can be used as a guideline researching the tendon reflexes in upper extremities.
Objective: To investigate the role of tendon reflex test in the diagnosis of diabetic peripheral neuropathy.
Method: Patellar tendon reflex (PTR) and achilles tendon reflex (ATR) were recorded in forty six diabetic patients and thirty seven normal adults by delivering tendon taps with an electric reflex hammer. Forty six diabetic patients were divided into two groups based on nerve conduction study and diabetic neuropathy score: group 1 consisted of nineteen patients with peripheral neuropathy, group 2 consisted of twenty seven patients without peripheral neuropathy. Multiple regression equations using latency as a variable dependent on age and height were used and upper crossing of the 3 standard deviation level with regression on height and age was considered abnormal.
Results: Mean latencies of PTR and ATR were prolonged in the diabetic patients in comparison with the controls (p＜0.01) and were prolonged in group 1 compared to group 2. In group 1, PTR was abnormal in 14 cases (sensitivity: 73.6%, specifity: 88%) and ATR was abnormal in 13 cases (sensitivity: 68.4%, specifity: 85.1%). In group 2, PTR was abnormal in 3 cases and ATR was abnormal in 4 cases.
Conclusion: Tendon reflex test would be a valuable supplement to conventional nerve conduction studies for detection of diabetic peripheral neuropathy, especially in the proximal segment.
Objective: We studied the prevalence of abnormal spontaneous activities in hemiplegic upper limbs, its nature and correlation with various clinical features.
Method: Forty-seven patients with hemiplegia from various central nerve system disease within about four months from disease onset were included in the study. The patients who showed obvious clinical evidence of peripheral nerve system disease were excluded. Motor and sensory nerve conduction studies (NCS) of median and ulnar nerves in hemiplegic limbs and motor nerve conduction studies of axillary nerve in both side were done. The cases demonstrating abnormal NCS were excluded in data analysis. Needle electromyography (EMG) was done in proximal muscles (deltoid, supraspinatus, infraspinatus, biceps brachii) and distal muscles (abductor pollicis brevis, abductor digiti quinti and first dorsal interosseous). Muscle strength of shoulder abduction and mass grasp were measured by manual muscle test. Development of shoulder hand syndrome was investigated through clinical examination.
Results: Mean period from onset of hemiplegia to EMG examination was 45.2⁑23.8 days (8∼108 days). Abnormal spontaneous activities were observed in 78% of patients in one of the muscles examined and were found more frequently in distal muscles than proximal muscles. Frequency of spontaneous activities was not significantly related to the time after onset of disease during the first 4 months. Spontaneous activities were more frequently observed in distal muscles with strength of less than good or fair grade. Patients with spontaneous activities showed tendency to higher incidence of shoulder hand syndrome but there was no statistical significance.
Conclusion: Hemiplegic upper limbs showed frequent abnormal spontaneous activities without definite peripheral nerve involvement. Its unique pattern of distribution should be kept in mind when we meet hemiplegic patients in electromyographic consultation.
Objective: To find the developing features of H reflex by the gradual increase of stimulation intensity, to evaluate the variability of each H reflex latency, and to verify the consistency of the side-to-side difference of bilateral H reflex latencies in normal population.
Method: Fifty normal persons (100 limbs) were studied. H reflexes were elicited using standardized technique from Braddom and Johnson.
Result: H reflex developed in the stimulation intensity at which M response was not evoked in 46 of total 100 limbs. The latency difference between the longest and shortest in each ipsilateral evoked potential was 0∼2.1 ms (mean 0.65±0.44 ms). In the side-to-side latency difference between the variously evoked H waves, the mean value of maximal one was 1.28±0.63 ms (0.4∼2.6 ms), and the mean value of the minimal one was 0.24±0.35 ms (0∼1.5 ms). The mean side-to-side latency difference between the H waves of maximal amplitudes was 0.69±0.46 ms (0.1∼1.6 ms), and the mean side-to-side difference between the shortest latencies was 0.61±0.53 ms (0∼2.1 ms). Among these findings the latency difference of the maximal amplitude was observed in 47 cases with 0∼1.5 ms, in 3 cases with more than 1.5 ms.
Conclusion: In diagnosing the S1 radiculopathy with the side-to-side latency difference it will be reasonable to use the latency of maximal amplitude or the shortest latency as diagnostic tool, and reevaluation will be needed with the diagnostic criteria of 1.5 ms latency difference.
Objective: Reflex sympathetic dystrophy (RSD) is a syndrome of post-traumatic neuropathic pain in association with dystrophic changes and signs of sympathetic overactivity. Pain following spinal cord injury occurs frequently, but RSD is not usually considered as one of the common sources of pain. There have only been a few reports of RSD in spinal cord injured patients, although this condition is well-known in the painful upper extremity of hemiplegia due to stroke. The purpose of this study was to investigate the rate of occurrence, characteristic clinical features and more objective evaluation tools for the diagnosis of RSD in cervical cord injured patients.
Method: Thirty-two cervical cord injured patients were evaluated for hand pain, swelling, vasomotor changes and dystrophic skin or nail changes. The patients were evaluated with studies such as three phase bone scintigrathy, digital infrared thermographic imaging (DITI) and plain roentgenograms of the hands.
Results: Eighteen patients (56.3%) were diagnosed as RSD based on the clinical symptoms and findings of three phase bone scintigraphy. Characteristic symptoms were hand pain, edema and dystrophic skin or nail changes, in the order of frequency. In patients with spasticity of the upper extremity, the incidence of RSD was higher than in patients without spasticity.
Conclusion: We should consider RSD as a cause of upper extremity pain in cervical cord injured patients. This will lead to early diagnosis and treatment of the condition and it will be helpful in preventing various complications.
In 12 Reflex Sympathetic Dystrophy(RSD) patients(13 cases) after the acute stroke, Three- phase Bone Scintigraphy(TBS) was performed to evaluate whether the amount of radioisotope reflects the disease activity of RSD. The diagnosis of RSD was based on Kozin's criteria(definite or probable group) and scintigraphic findings(increased radioisotope uptake in all three phases). Initial TBS was performed within 10 days after the onset of clinical symptoms and it was followed up within 5days after the short term steroids therapy. Before and after the steroids therapy, patients were evaluated with respect to pain, swelling and allodynia. Radioisotope uptake of ROI(Regions Of Interest) of all three images was calculated semiquantitatively in initial and follow up scintigraphy.
Pain, swelling and allodynia of the affected hand were improved in all patients after short-term oral corticosteroids therapy. Radioisotope uptake in blood flow image(11 patients, 12 cases) and blood pool image(11 patients, 12 cases) were decreased(p＜0.05), but radioisotope uptake in delayed image was not decreased(p＞0.05).
We concluded that radioisotope uptake in blood flow and blood pool images could reflect disease activity of RSD. It was suggested that decreased capillary vascular permeability by corticosteroids resulted in decreased blood flow and blood pool. The semiquantitative evaluation of TBS may be useful for monitoring the response to therapeutic intervention.
The role of inflammatory mediators in RSD and pharmacologic effect of corticosteroids were also discussed.
Objective: The purpose of this study is to develop an experimental spinal cord injury spasticity model using rabbits and to evaluate a quantitative spasticity measure.
Method: After an general anesthesia, 19 rabbits out of total 24 rabbits were laminectomized posteriorly and the spinal cords contused with 15 g⁓20 cm weight drop around 11th and 12th thoracic cord. After two weeks, behavioral analysis and clinical measurements of hindlimb spasticity were assessed. After that, rabbits' triceps surae was dissected and the length-tension plot was obtained by stretching it 5 mm, 2 mm/sec. And then the stiffenss of stretch reflex was determined from the length-tension plot. The stiffness of stretch reflex of the five normal control group was measured.
Results: 1) The measure was possible among 15 out of 19 spinal cord injured rabbits. One out of 19 rabbits was died
from urinary infection. Two rabbits was died from intraop-
erative bleeding at 2 weeks. Another one was excluded from the measurement due to joint contracture. 2) All of 15 rabbits showed clinical spasticity of hindlimb in 2 weeks. The spasticity was increased after the 4th day. 3) On the length-tension plot, the stiffness of stretch reflex of 15 rabbits significantly increased more than that of 5 normal group. 4) The total stiffness is correlated with the deep tendon reflex of knee and muscle tone of ankle. The stiffness of stretch reflex is weakly correlated with the deep tendon reflex of knee, digital hyperreflexia and ankle clonus.
Conclusion: The experimental spinal cord injury model and the quantitative spasticity measure method would contribute to measure the effect of the new therapy of spasticity more accurately, and to establish a principle of the new therapy. In addition, the study is expected to contribute to establish pathophysiology of spasticity. (J Korean Acad Rehab Med 2002; 26: 37-45)
Trigeminal neuropathy commonly presents prolonged disorder of sensation in the distribution of the fifth cranial nerve of unilateral side and involves more than one division. We are reporting a case of a pure trigeminal motor neuropathy without sensory symptoms.
38-year-old man suffered from a mild common cold followed by progressive weakness and wasting of right masticatory muscles without pain or sensory change. Neurological examination revealed sunken cheek and temple area with weakness of the masticatory muscles and normal sensation of the face and normal taste. And all other cranial nerve were intact. Electrophysiological study revealed abnormal spontaneous activities with no voluntary motor unit potentials from the right temporalis and masseter muscles. The masseter reflex examination elicited by reflex hammer stimulation showed very small amplitudes from the right side. Trigeminal evoked potential, brainstem evoked potential and electrophysiological trigeminal blink reflex were normal. The imaging studies of the brain(CT and MRI) demonstrated atrophy of the right trigeminal motor nerve innervated muscles suggesting a pure trigeminal motor neuropathy without sensory involvement. We suspected a viral infection as the cause of their condition.
Method: The subjects were 37 patients and 30 normal controls. The patient group was composed of 28 patients with L5 radiculopathy and 9 patients with S1 radiculopathy, which were confirmed by clinical, radiological, and electrodiagnostic studies. Tibialis anterior H-reflex (TA-H reflex) was recorded from maximally contracting tibialis anterior muscle by averaging technique and submaximal stimulation of common peroneal nerve. Sensitivities and specificities were delineated from the several diagnostic criteria.
Results: In the normal controls, mean side to side difference in the TA-H reflex latency was 0.66⁑0.48 msec and mean amplitude ratio was 75⁑16%. The diagnostic criteria of abnormal TA-H reflex were latency difference above 1.62 msec and amplitude ratio less than 42.2%. The abnormal TA-H reflexes were shown in 17 out of 28 patients with L5 radiculopathy and 1 out of 9 patients with S1 radiculopathy. Sensitivity and specificity of TA-H reflex as a diagnostic criteria of L5 radiculopathy were 61% and 89%, respectively.
Conclusion: Tibialis anterior H-reflex might be useful in the diagnosis of L5 radiculopathy.
Objective: We designed this study to evaluate muscle tone by using a biomechanical method and to provide data for the future studies about muscle tone.
Method: We evaluated 29 subjects without known neuromuscalar diseases using the biomechanical method. Both plantar flexors of each subject were passively stretched by isokinetic dynamometer from 30oplantar flexion position to 10odorsiflexion position. Peak eccentric torque (PET) and torque threshold angle (TTA) were calculated at angular velocity of 10o/sec, 90o/sec and 300o/sec. Regression lines from torque/position curve at 10o/sec and 300o/sec were considered an intrinsic stiffness index (ISI) and total stiffness index (TSI). Stretch reflex threshold speed (SRTS) was defined as the minimum speed of plantar flexion movement in which EMG reflex activity in plantar flexor muscles is induced.
Results: The mean of TTA was higher in 10o/sec than in 300o/sec. The means of ISI and TSI were 0.11⁑0.08, and 0.18⁑0.04. The mean of SRTS was 125.2⁑48.3o. No statistical difference in each parameter was found according to the side or gender.
Conclusion: ISI, TSI, PET, TTA and SRTS using a biomechanical method are thought to be useful parameters for the quantitative assessment of muscle tone change of ankle plantar flexors.
Method: Spinal cords of 25 rabbits were contused by 20 g⁓20 cm weight drop in the 11th thoracic spine. After 2 weeks, muscle stretch reflex was measured. Triceps surae was dissected and stretched for 5 mm at the rate of 2 mm/sec and the length-tension curve were obtained. The slope in the length-tension curve was defined as stiffness index (SI). After baseline measurement, group I (n=6) received 50 mg/kg GBP IM injection and group II (n=8) received 100 mg/kg GBP IM injection, but control group (n=5) did not. Muscle stretch reflex was measured again after 30 minutes and 60 minutes, and then after sciatic nerve section. Active tension was calculated by subtracting passive tension from total tension. Proportion of SI was calculated by dividing follow-up SI with baseline SI.
Results: The proportion of SI of active tension reduced significantly at 30 minutes and 60 minutes compared to baseline (p＜0.001, p＜0.001). The proportion of SI of active tension in both group I and group II reduced significantly than control group (p=0.041, p＜0.001). The proportion of SI of active tension in group II reduced than group I, but it was not statistically significant (p=0.166).
Conclusion: The GBP reduced significantly muscle stretch reflex in spinal cord injured rabbits and showed dose-response tendency.
Objectives: To determine the effect of facilitation on H reflex side-to-side amplitude ratio and to determine the effect of averaging under the assumption that an averaging could further stabilize the amplitude ratio in a facilitated condition.
Method: FCR H reflex amplitude ratios of direct and averaged potentials were measured in fifty asymptomatic subjects under three conditions, during rest, during a constant 5 pound isometric contraction under the hand-dynamometer monitoring, and during a moderate constant isometric contraction under the electromyographer's verbal guidance.
Results: The lower limits of the amplitude ratios that encompass 97.5% of subjects by the percentile method under three conditions were as follows; (1) during the rest (n=37); 0.47 (direct) and 0.50 (average), (2) during the constant 5 pound isometric contraction under the hand- dynamometer monitoring; 0.47 (direct) and 0.48 (average), and (3) during the moderate constant isometric contraction under the electromyographer's verbal guidance; 0.48 (direct) and 0.46 (average), respectively.
Conclusion: There seems to be no definite effect of facilitation and averaging on H reflex amplitude ratio. H reflex amplitude ratio measured in facilitated condition without averaging is still useful for the diagnosis of unilateral radiculopathy.
Objective: The purpose of this study was to investigate the influence of hyperactive stretch reflexes and contralateral adductor spread on the prognosis of gait in cerebral palsy with spastic diplegia and to investigate the reflex characteristics of spastic patients according to motor development.
Method: Thirty three children with spastic diplegia were examined. Compound muscle action potentials elicited by electrical hammer were used for quantification of stretch reflexes. Clinical spasticity was evaluated with the modified Ashworth scale and re-evaluation was done at least for 18 months. The patients were classified as 3 groups according to the stage of motor development: Group I consisted of children who were unable to sit; Group II children were able to pull to stand but unable to walk independently; Group III children could walk independently more than ten steps. Reflex irradiation, amplitudes of compound muscle action potentials, amplitude ratios, and Ashworth scores were analyzed and compared between the groups. Twenty four normal infants and 18 children were examined as control.
Results: Contralateral adductor responses were elicited with patellar tendon tap stimulation in all spastic diplegic children. The amplitudes of contralateral adductor were 2.41 mV in group I, 1.75 mV in group II, and 1.21 mV in group III. The amplitude ratio of contralateral adductor to rectus femoris were 0.53 in group I, 0.40 in group II, and 0.26 in group III, respectively, and correlated with the degree of spasticity.
Conclusion: The stretch reflex responses in children with cerebral palsy with spastic diplegia were highly exaggerated, and correlated with motor development. Spread of reflexes to contralateral adductor muscle would be in clinical and electrophysiological value.
Objective: The purpose of this study is to assess the changes of skin temperature quantitatively in the stroke patients with reflex sympathetic dystrophy syndrome (RSDS) using thermography according to their clinical phases as well as changes after treatment.
Method: Patient group was consisted of 17 stroke patients with RSDS. Mean onset time of RSDS after stroke was 10.6 weeks. All patients were assessed by triphasic bone scan and clinically classified by phase I, II, and III. Control group was consisted of 9 stroke patients without RSDS. Temperature difference between affected side and unaffected side in wrist and hand regions were assessed in all subjects using Thermovision 570 (Agema Infrared Systems, USA) when initial clinical diagnosis was made. Seven patients were reassessed after high dose steroid and physical therapy.
Results: In patients with phase I RSDS, affected wrist and hand showed higher temperature distribution than the unaffected side. On the other hand, patients with phase II and III showed lower temperature in the affected side. The mean temperature difference in patients with phase I RSDS was significantly greater than control group. After treatment, skin temperature of affected side was decreased in phase I patients, but increased in phase II patients. Skin temperature difference tended to be normalized after successful treatment.
Conclusion: Using thermography, temperature change of affected hand can be assessed quantitatively in stroke patients with RSDS. The thermography is considered to be a useful tool for evaluation of clinical phases and treatment effect in these patients.
Objective: To investigate and compare the vibratory inhibition of H-reflex in the subjects with and without brain injury.
Method: H-reflex and the vibratory inhibition of H-reflexes were evaluated in thirty two limbs in subjects without brain injury and twenty two limbs in the brain injury patients. The maximal amplitudes of H-reflexes were recorded before and while vibrating the Achilles tendon. The ratio of the two trials (vibratory maximal H-reflex amplitude / previbratory maximal H-reflex amplitude) was defined as 'H-reflex vibratory inhibition'. H-reflex vibratory inhibition was correlated to the spasticity (Asworth scale).
Results: The mean values of H-reflex vibratory inhibition were 0.5361⁑0.0373 in the control group and 0.7539⁑0.0543 in the brain injured group. There was a significant difference between two groups. H-reflex vibratory inhibition tends to increase as the spasticity increases.
Conclusion: The vibratory inhibition of H-reflex was significantly decreased in the brain injured patients than in the controls. We conclude that the H-reflex vibratory inhibition can be used in the evaluation of the spasticity.
Objective: To determine the differences of the tendon reflex responses (TRR) between medial and lateral heads of gastrocnemius muscles in healthy subject and spastic patients.
Method: The TRR of medial and lateral heads were evaluated in 20 healthy subjects and 20 spastic hemiplegic patients. From 5 repeated trials on each subject, the shortest latency and duration, and the largest peak-to-peak amplitude of TRR were chosen for the representative value.
Results: 1. The evoked potentials by tendon reflex in medial head of gastrocnemius demonstrated significantly higher amplitude than in the lateral head of gastrocnemius in patients (P＜0.05) and the evoked potentials in lateral head of gastrocnemius demonstrated significantly higher amplitude than in the medial head of gastrocnemius in healthy patients (P＜0.05). 2. Mean latency of the evoked potentials by a tendon reflex in both heads of gastrocnemius in the spastic patients and healthy subjects were not significantly different (P＞0.05). 3. Mean duration of the evoked potentials by a tendon reflex in both heads of gastrocnemius in spastic patients and healthy subjects were not significantly different (P＞0.05).
Conclusion: These results indicate that the medial head of gastrocnemius is activated more than the lateral head of gastrocnemius by a tendon reflex in recording evoked potentials of the spastic patients.
Leprosy is an infectious disease caused by Mycobacterium leprae and characterized by dermal and peripheral nerve lesions. The facial nerve is also frequently involved in leprosy. There are a few electrophysiologic studies on the facial nerve involvement in leprosy patients, but there is no electrophysiologic study on the facial nerve involvement in cured leprosy patitents. So we performed facial nerve conduction study and Blink reflex study in 19 cured leprosy patients who have been managed with Dapsone for a long time. Facial motor latencies were prolonged in 11 patients(57.9%).: 10 of 15 patients in lepromatous type; 1 of 4 patients in tuberculoid type. Prolonged latencies were shown in temporal branch, zygomatic branch, buccal branch, and mandibular branch in 9(47.4%), 6(31.6%), 5(26.3%), and 3(15.8%), respectively. Blink reflex study suggests combined facial nerve and trigeminal nerve lesion in 2 patients.
This study was designed to verify the validity of bulbocavernosus reflex latency(BCRL) and pudendal somatosensory evoked potential(SEP) in the evaluation of neurogenic erectile dysfunction and to lay out a scheme to uplift the diagnostic accuracy of BCRL and pudendal SEP. Eighty four subjects who were referred to Seoul National University Hospital EMG laboratory for the evaluation of the erectile dysfunction were examined. At first, history taking, physical examination, measurement of serum hormone level, rigiscan with audiovisual sexual stimulation were performed. In the next step, intracorporial papaverine injection, nocturnal penile tumescence test, BCRL and pudendal SEP were performed as indicated. Then the results of BCRL and pudendal SEP were compared to the final diagnosis obtained through additional studies. Psychogenic cause was most common and neurogenic, vascular, and hormonal causes followed. The diagnostic sensitivity of BCRL and pudendal SEP in the discrimination of neurogenic cases from nonneurogenic cases was 89.5% and 93.7%, respectively. The specificity was 89.7% and 64.7% in order. Among twenty seven subjects with abnormal BCRL or pudendal SEP, eight subjects were confirmed as psychogenic impotence at the final diagnosis. But psychogenic impotence was not found among nine subjects who had abnormal BCRL and pudendal SEP. Twenty three subjects with abnormal BCRL were divided into delayed latency group and no response group. Among thirteen subjects of delayed latency group, psychogenic cases were six and among ten subjects of no response group, psychogenic case was not found. In the evaluation of neurogenic impotence, BCRL was a sensitive and specific tool while pudendal SEP was sensitive but less specific. BCRL alone or pudendal SEP alone would be inadequate for the evaluation of neurogenic impotence, especially in discrimination with psychogenic one. To improve diagnostic accuracy in the evaluation of impotence, BCRL and pudendal SEP should be checked out all together. In the situation when only BCRL is available, it is recommendable to take unevokable bulbocavernosus reflex as meaningful.
The effect of electrical nerve stimulation are controversial because of the inconsistent variables of stimulating current and electrophysiologic study. The purposes of this study are to reconfirm the electrophysiolgic changes by electrical stimulation of the peripheral nerve that had been reported in 1993, and to monitor how long they will be maintained. In this study, the following conditioning stimulations were applied to 20 healthy volunteers; interferential current(frequency: 80∼100 Hz, intensity: 27∼34 mA) on the sacral paraspinal area. The H reflex, the F response, and the somatosensory evoked potential(SEP) of the tibial nerve were evaluated as the electrophysiologic study before, immediately after, 30 minutes, 60 minutes, and 120 minutes after the above conditioning stimulation. The following results were obtained;
1) Latencies of the H reflex, the F response and the SEP(P1), and the F wave conduction time, the F wave conduction velocity and the F ratio in the tibial nerve conduction study were increased by conditioning stimulation of the proximal peripheral nerves(P＞0.01).
2) Changes of the amplitude of the H reflex, the H/M ratio, and the amplitude(P1N1) of the tibial SEP were not significant in the same conditioning stimulation(P＞0.05).
3) Prolongations of the latencies of H reflex, F response and P1 SEP of the tibial nerve were the most significant immediately after conditioning stimulation and sustained for 45 minutes after conditioning on average (P＜0.01).
The above results suggest that certain conditional electrical stimulation of the peripheral nerves causes reversible changes in the conduction of the H reflex, the F response and the SEP and they may be inhibitory effect of the proximal conduction via the spinal cord.
Objective: To assess the facial and trigeminal nerve involvement in diabetic patients using blink reflex study and direct facial motor conduction study.
Method: The subjects were 397 diabetic patients and 34 normal controls. Diabetic patients were subdivided into two groups based on the findings of nerve conduction studies of limb nerves.: Group I, patients with diabetic polyneuropathy; Group II, patients without diabetic polyneuropathy. The blink reflexes and direct facial motor responses and R1 latency/direct response latency (R/D) ratio were obtained in all the subjects. R1 latency was correlated to the findings of nerve conduction studies of limb nerves.
Results: 1) R1 latencies or R2 latencies were abnormally prolonged in 22.4% of Group I, 3.3% of Group II, and direct facial responses were abnormal in 11.8% of Group I, 2% of Group II. 2) There were no significant differences in R/D ratio between the two groups. 3) These findings suggest that not only the facial nerve, but also the trigeminal nerve or brain stem could be affected in diabetic patients with polyneuropathy.
Conclusion: In diabetic patients, blink reflex can provide useful information in determining the degree and distribution of cranial nerve and brain stem lesions.
Method: Retrospective chart review was performed in 561 patients. Among 561 stroke patients, 116 subjects were recruited and classified into two groups: patient group, 43 cases with RSD; control group, 73 cases without RSD. Upper extremity function was assessed based on feeding, dressing and personal hygiene scores of the modified Barthel index at the beginning of rehabilitation treatment and at the time of discharge. Causes of stroke and length of stay were recorded. Median nerve-somatosensory evoked
potential studies were performed and assessed.
Results: The incidence of RSD was 7.7% and the time to development of RSD was 62.3±34.1 days after the onset of stroke. There was no significant difference in functional status between two groups at initial and final evaluation. The upper extremity function had improved in both groups although the length of stay was longer in patient group. SSEP abnormalities were more frequent in the patient group.
Conclusion: The presence of well-managed RSD affected neither the functional status nor the functional recovery of upper extremity in stroke patients. (J Korean Acad Rehab Med 2003; 27: 480-484)
Objective: This study was designed to evaluate the usefulness of stretch reflex threshold speed (SRTS) in biomechanical assesment of spasticity of hemiplegic patients.
Method: Thirty-eight hemiplegic patients and twenty-seven control subjects were studied. The spasticity of ankle plantar flexor muscles were assessed both clinically and biomechanically. Modified Ashworth scale (MAS) and Brunnstrom stage were used in clinical assessment. For biomechanical assessment, ankle plantar flexor muscles were stretched isokinetically while EMG signals were recorded simultaneously. SRTS was defined as a minimum angular velocity in which EMG signals evoked by stretch reflex were recorded.
Results: SRTSs of ankle plantar flexors were 128.1⁑47.1o/sec in control group, 163.7⁑79.7o/sec in intact legs, and 83.4⁑69.1o/sec in involved legs of hemiplegic group. STRS was significantly lower in involved legs of hemiplegic group than in intact legs of hemiplegic group and control group. Significant reverse correlation was observed between SRTS and MAS. There was significant difference in SRTS between MAS 0 group and other groups. The patients with Brunnstrom stage 3 and 4 groups showed decreased SRTS compared to the patients with other groups.
Conclusion: SRTS is thought to reflect increased excitability of stretch reflex and seems to be one of useful parameters in quantitative assessment of spasticity.
Early onset cerebellar ataxia with retained tendon reflexes is distinctive clinical syndrome characterized by progressive cerebellar ataxia of unknown etiology with an onset within the first two decades. This disorder was distinguished from Friedreich's ataxia by the preservation of the deep tendon reflexes. There is 22-year-old male with 13 year history of slowly progressive cerebellar ataxia and dysarthria. His elder brother, also, has milder clinical manifestations, electrophysiological and radiological abnormalities. We experienced two cases of early onset cerebellar ataxia with retained tendon reflexes developed in brothers which was diagnosed by clinical manifestations, electrophysiologic, radiologic studies and report with brief review of related literatures.
Objective: To determine whether the cause of sympathetic dysfunction is due to increased regional sympathetic outflow or receptor supersensitivity to circulating catecholamines in the pathogenesis of reflex sympathetic dystrophy in hemiplegia.
Method: Ten hemiplegic patients with reflex sympathetic dystrophy were instructed to refrain from smoking or using caffeine and alcohol, and medications that influence catecholamine metabolism were witheld for 24 hours before blood sampling. Patients with cardiovascular disease, diabetes or abnormal liver and renal function tests were excluded from the study. Patients with a history of sympathectomy were also excluded. Ten hemiplegic patients without reflex sympathetic dystrophy served as the control group. Both groups of patients rested in supine position in a quiet room for 30 minutes. A needle with heparin cap was inserted into the dorsal venous arches of the affected hand and patients rested for another 20 minutes, after which blood was drawn through the heparin cap. The blood samples were assayed using high-performance liquid chromatography (HPLC) and norepinephrine and epinephrine were detected electrochemically. 24 hour urine was collected during rest and vanillylmandelic acid (VMA) and metanephrine were also detected using HPLC.
Results: The mean plasma norepinephrine levels were 1.05⁑0.24 ng/ml and 0.47⁑0.06 ng/ml in RSD affected and unaffected groups respectively, and the plasma norepinephrine level was significantly higher in the patient group with reflex sympathetic dystrophy (p＜0.05). The plasma epinephrine and 24-hour urine VMA and metanephrine levels were not significantly different in two groups.
Conclusion: These results may support a hypothesis of increased regional sympathetic outflow in the pathogenesis of reflex sympathetic dystrophy in hemiplegia.
When recovery of specific reflexes after acute spinal cord injury are delayed or absent, we should consider an acute local complication or other factors that influence reflex function. We observed three spinal cord injury cases with a long-standing delayed plantar reflex and no evolution of Babinski sign despite enough recovery time had passed for the flexor spasm and all deep tendon reflexes of the lower extremities. In these cases we confirmed common peroneal nerve neuropathy at the fibular head by the nerve conduction study and electromyography. Long-standing delayed plantar reflex without evolution of Babinski sign, beyond expected recovery period, would be considered as a sign of local complication such as common peroneal nerve injury.
Objective: To evaluate the effects of botulinum toxin A (BT) dilution volume and post- injection exercise with electrical stimulation on muscle paralysis.
Method: Eighteen New Zealand white rabbits are randomly assigned to 0.1 ml dilution group, 0.5 ml dilution group or control group. Control group did not receive any injection and 10 units of BT was diluted with 0.1 ml (B1) or 0.5 ml (B5) normal saline and injected to the both gastrocnemius muscles. The right lower limbs of experimental groups did not have any treatment after botulinum toxin A injection (B1C, B5C) and left lower limbs had stretching exercise after injection (B1S, B5S) for 2 hours using the pneumatic kicking machine. Electrical stimulation was also applied to the gastrocnemius muscle with the intensity of 20 mA to 30 mA to evoke plantar flexion of ankle joint. Muscle paralysis effect of BT was evaluated with compound muscle action potential (CMAP) amplitude of gastrocnemius muscle with the sciatic nerve stimulation before and 1 week after injection.
Results: There were significant CMAP amplitude decreases in all animals after BT injection. There were significant decreases of CMAP amplitudes in B5 group compared with that of B1 group (p＜0.001). Left limbs with stretching exercise and electrical stimulation showed lower CMAP amplitude (p=0.01) compared with right limbs which did not have any treatment after BT injection.
Conclusion: To maximize muscle paralysis effect of the botulinum toxin A, increasing dilution volume and performing post-injection stretching exercise with electrical stimulation are considered a good strategy.
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