To introduce the Korean Database of Cerebral Palsy (KDCP) and to provide the first report on characteristics of subjects with cerebral palsy (CP).
The KDCP is a nationwide database of subjects with CP, which includes a total of 773 subjects. Characteristics such as demography, birth history, onset and type of CP, brain magnetic resonance imaging (MRI) findings, functional ability and accompanying impairments, were extracted and analyzed.
Preterm delivery and low birth weight were found in 59.51% and 60.28% of subjects, respectively. Postnatally acquired CP was 15.3%. The distribution of CP was 87.32%, 5.17%, and 1.81% for spastic, dyskinetic, and ataxic types, respectively. Functional ability was the worst in dyskinetic CP, as compared to other types of CP. Speech-language disorder (43.9%), ophthalmologic impairment (32.9%), and intellectual disability (30.3%) were the three most common accompanying impairments. The number of accompanying impairments was elevated in subjects with preterm birth and low birth weight. Brain MRI showed normal findings, malformations, and non-malformations in 10.62%, 9.56%, and 77.35% of subjects, respectively. Subjects with normal MRI findings had better functional ability than subjects with other MRI findings. MRI findings of a non-malformation origin, such as periventricular leukomalacia, were more common in subjects with preterm birth and low birth weight.
The KDCP and its first report are introduced in this report, wherein the KDCP established agreement on terminologies of CP. This study added information on the characteristics of subjects with CP in South Korea, which can now be compared to those of other countries and ethnicities.
Cerebral palsy (CP) describes a group of permanent disorders in the development of movement and posture that cause activity limitation, and are attributed to non-progressive disturbances that occurred in the developing fetal or infant brain [
Understanding the characteristics and prevalence of CP is an essential step for management and prevention of CP. The characteristics and prevalence of CP are influenced by several factors such as availability of medical services, the level of medical knowledge and technology, and socioeconomic status of each society. While the majority of data on characteristics and prevalence of CP are mainly from the European countries, Australia and the United States, there are few data from Asian countries. Moreover, agreement on terminologies such as definitions, classification and accompanying impairments of CP is an essential requirement for comparison of data from different countries and ethnicities.
In 2007, the task force team of the Korean Database of Cerebral Palsy (KDCP) was formed by the Korean Society of Pediatric Rehabilitation and Developmental Medicine (KSPRDM). KSPRDM is the academic association of professionals working with children with disability throughout South Korea. It plays a central role in the field of clinical and academic area of pediatric rehabilitation, and is pivotal in the leadership of policies regarding children with disability in South Korea. The aim of the KDCP was to set up a nationwide multicenter database of subjects with CP, to improve understanding of the characteristics of CP, and to provide a framework for further research as well as provide a nationwide data of CP. The first task of KDCP was to establish an agreement on terminologies such as definitions, classification and accompanying impairments. The KDCP was developed in January 2009, and was envisioned to provide the first nationwide data on the characteristics of CP in South Korea, based on the uniform classification systems and language. This data would be useful in understanding the clinical characteristics of CP of Koreans, and used as Asian data on CP to be compared with western countries.
The objective of this study is to introduce the KDCP and provide its first report on characteristics of subjects with CP in South Korea.
This study was approved by the Institutional Review Board (No. AJIRB-MED-MDB-13-102). The study was conducted using data extracted from the KDCP.
The KDCP is an online database containing details from a nationwide multicenter cohort of subjects with CP. Data are entered into the KDCP by voluntary members of the KSPRDM. The members of KSPRDM are board-certified doctors in rehabilitation medicine who work with children having disabilities, distributed throughout South Korea. The KDCP consists of two databases: KDCP1 is the database for subjects younger than 4 years, and KDCP2 is for subjects of ages 4 years or older. When subjects of KDCP1 reach the age 4 years or older, new data of the same subjects are entered into KDCP2, thus facilitating the follow-up of longitudinal changes of characteristics of subjects.
To be enrolled in the KDCP, a subject must be diag-nosed with CP and at least 12 months-of-age at the time of data entry. Data queries in KDCP is provided with definition, which was based on previous reports and complemented with video clips if necessary [
The structure of the KDCP (
CP is defined as a group of permanent disorders in the development of movement and posture causing activity limitation, attributed to non-progressive disturbances that occurred in the developing fetal or infant brain. CP cases resulting from a disturbance occurring past 36 months of life were excluded in the KDCP [
Prenatal/perinatal CP means that the etiological event causing CP was thought to occur during the prenatal or perinatal period. Postnatally acquired CP means that the etiological event causing CP could have occurred during the postnatal period, after the 28 day of life [
Brain MRI findings were classified according to previous articles [
Records were included in this study, if all the following three inclusion criteria were met: (1) subjects were believed to have, or were suspected of having, CP; (2) subjects were at least 12 months-of-age at the time of data entry; (3) subject records were complete, with all the mandatory data. Name, last three digits of their social security numbers, and their date of birth, were used to identify duplicated data. Subjects whose data appeared in both KDCP1 and KDCP2, were excluded from this study.
We analyzed all mandatory data in the KDCP1 and KDCP2, along with optional data such as MRI findings and etiologic events for postnatally acquired CP. GMFCS levels and the number of accompanying impairments were analyzed according to gestational age, birth weight, onset of CP, plurality of pregnancy, type of CP, and type of brain MRI findings. Gestational age and birth weight were analyzed in respect to brain MRI findings.
Data were analyzed using independent-sample t-tests for comparison of GMFCS and the number of accompanying impairments, by gestational age, birth weight, onset of CP and plurality of pregnancy. One-way analysis of variance test compared the GMFCS and the number of accompanying impairments according to type of CP and type of brain MRI findings. If the results were statistically significant, Fisher least significant difference (LSD) test was used to determine which of the comparison were statistically significant. Statistical significance was set at a <0.05. SPSS ver. 19.0 (IBM, Armonk, NY, USA) was used for the statistical analysis.
The flow diagram for record selection is shown in
Postnatally acquired CP was reported for 118 (15.27%) subjects. The etiologic events of postnatally acquired CP were reported in 91 subjects; these are presented in
The distributions of the subjects according to the type of CP are presented in
Accompanying impairments are shown in
Brain MRIs were reported to be taken for 660 subjects (85.4%), and brain MRI findings were available for 565 of these subjects. Brain MRI findings are listed in
A comparison of gestational age and birth weight with brain MRI finings is shown in
Subgroup analyses of GMFCS and the number of accompanying impairments were performed according to the characteristics of subjects, as shown in
There were significantly more accompanying impairments in subjects born before 37 weeks of gestation, and subjects with a birth weight less than 2,500 g (p<0.001). There was no significant difference in the number of accompanying impairments by the onset of CP, plurality of pregnancy, and type of CP, and brain MRI findings.
The KDCP and its first report are introduced in this paper, where the KDCP established an agreement of termi-nologies for CP. This is the largest study to be performed on the nationwide CP cohort in South Korea. The key findings of this study are (1) preterm delivery and low birth weight were found in 59.51% and 60.28%, respectively, of subjects with CP, which is a much higher rate than 4%–6% found in the general population of South Korea; (2) delivery by caesarean section accounted for 46.40% of the subjects. Considering that the overall rate of caesarean section in South Korea was 36.0%–36.9% during the period of 2007 to 2012 [
This study has several major strengths. (1) Prior to the KDCP, there were substantial variations in the use of terms regarding definition, classification, severity, topographic distribution, and associated impairments of CP. Therefore, in order to avoid a higher proportion of misclassifications and to be less dependent on individual judgment, the KDCP provided strict validation criteria, along with pop-up tips on the online database. (2) The KDCP also requires validation of a diagnosis before a case is input, and this is done by board-certified doctors in rehabilitation medicine throughout South Korea. These doctors have specialist experience with children with disabilities, including CP. (3) The KDCP is the largest nationwide cohort of CP in South Korea. On the basis of these strengths, the KDCP may provide less unbiased data on the characteristics of CP in South Korea.
The overall results must be interpreted with an appropriate degree of caution, since this study also has several limitation. (1) Case selection could be biased by several factors, including whether subjects and their guardians could afford the time and expense to visit hospitals rather than private clinics, whether parents or guardians felt worthwhile enough for themselves and their child to make the journey, and whether or not highly specialized care was required. (2) As the study data came from a database, and not a registry or survey, the prevalence of CP in the general population could not be determined. Registers hold databases of patients with the disease of interest, but are distinct from clinical databases in that cases enrolled in a register are drawn from a clearly defined denominator population rather than from hospitals [
When the current data is compared with previous reports, this data showed similar findings as the previous studies for most characteristics, such as subjects with CP born with preterm birth, low birth weight [
In conclusion, the KDCP and its first report are introduced in this paper, where the KDCP establishes an agreement of terminologies for CP. This is the first nationwide report on the characteristics of subjects with CP in South Korea. Although there are some limitations, we believe that this study is able to add knowledge on the characteristics of subjects with CP. Further research is required to study the prevalence of CP, as well as the longitudinal change in subjects.
The Korean Database of Cerebral Palsy was funded by Allergan Korea Ltd. Grateful thanks are expressed to Doctors Jae-Young Han, Kyu Bum Lee, Sang Joon Kim, Soo A Kim, Bong-Ok Kim, Jin Hee Park, Sang-Jee Lee, Hyun-Jung Chang, Mi-Riam Hwang, Eun Sook Park, Seong Il Lim, Su Min Son, Yu Ryun Lee, Jae Yong Jeon, Soon Tak Jeong, Myung-Eun Chung, Cheong Hoon Seo, Dongwook Rha, and Jong Hoon Kim, for their participation in the Korean Database of Cerebral Palsy.
The structure of the Korean Database of Cerebral Palsy. (A) The first page of the Korean Database of Cerebral Palsy for subjects of age ≥1 year and <4 years. (B) The first page of the Korean Database of Cerebral Palsy for subjects of age ≥4 years.
Supplementary materials can be found via
Comparison of gestational age and birth weight with brain MRI findings (n=565)
Comparison of GMFCS and the number of accompanying impairments with the characteristics of subjects (n=773)
Values are presented as number (%) or mean±standard deviation (range).
MRI, magnetic resonance imaging; PVL, periventricular leukomalacia.