Cerebral Palsy in North Indian Children: Clinico-etiological Profile and Comorbidities.

AIMS AND
OBJECTIVES: Cerebral palsy (CP) is a common motor disability in children. This study aimed at elaborating various comorbidities and etiologies and also at correlating motor disability with other disabilities.
MATERIAL AND METHODS: This hospital-based study was conducted in the outpatient department of a tertiary care hospital in Delhi on 160 children with CP in the age group 2-15 years. A detailed history taking and examination were conducted for each patient and appropriate investigations were performed.
RESULTS: Most patients, that is 64.4%, were younger than 5 years of age and 72.5% were males. Most common etiology was birth asphyxia (41.9%). Maximum patients were of bilateral spastic (spastic quadriplegic) CP accounting 43.1%. Intellectual disability was the most common comorbidity across all subtypes of CP followed by epilepsy. Comorbidities such as epilepsy and all visual problems except optic atrophy were more common in spastic quadriplegic CP. Hearing, speech impairment, and optic atrophy were more common in dyskinetic CP. Chewing, swallowing, and drooling problems were more common in spastic quadriplegic CP.
CONCLUSION: Most common risk factor of CP is birth asphyxia; thus, by improving health care facilities, its incidence can be reduced. CP affects not only motor functions but also other important functions of body as well, and the more severe the motor disabilities, the more are other comorbidities and their intensity also increases with that of the intensity of brain insult.

INTRODUCTION

Cerebral palsy (CP) is an umbrella term covering a group of disorders arising from a nonprogressive injury to the brain during its development. It is characterized by motor impairment and incoordination. Though the insult is static, the clinical manifestations may vary over time with maturation of the central nervous system (CNS).[1] Motor disability is often accompanied by abnormalities of cognition, vision, hearing, speech and language, growth, and behavior among others.

The prevalence of CP in Western countries is estimated to be 2.4 per 1000 children.[2] It is expected to be higher in India owing to poor infrastructure of health care services. Our study attempted to study the comorbidities associated with CP and their relationship to the motor/neurologic subtype.

MATERIALS AND METHODS

This descriptive observational cross-sectional study was carried out at Kalawati Saran Children’s Hospital (KSCH), a tertiary level pediatric hospital in New Delhi. The study was approved by the institutional ethics committee. Children between the ages of 2 and 15 years presenting to the outpatient department of KSCH from November 2010 to March 2012 with delayed motor milestones and nonprogressive disorder of the CNS were enrolled for the study.

Patients with congenital anomalies, progressive disease, musculoskeletal cause (congenital dislocation of HIP, myopathy), and concurrent chronic systemic illness (cardiac, renal, etc) were excluded.

Informed consent was taken from parent/guardian of the child. Detailed history taking and thorough examination of the patient were undertaken and recorded in a predesigned pro forma with particular emphasis on the type and extent of motor disabilities, history of seizures including need for antiepileptic therapy, impairments in vision and/or hearing, abnormalities of speech and language development, poor cognitive functions, and delayed or improper social milestones.

All participants were classified into bilateral spastic (spastic quadriplegic) CP, bilateral spastic CP with lower limb predominance (spastic diplegic) CP, unilateral spastic (spastic hemiplegic) CP, or dyskinetic CP using Surveillance of Cerebral Palsy in Europe classification.[3]

Motor assessment was performed using Gross Motor Function Classification System (GMFCS), developed by Palisano et al.[4] It describes the functional characteristics in five levels, from I to V. In this, class I denotes best functional achievement and class V denotes worst functional capability.

Patients of epilepsy were identified according to International Leage Against Epilepsy definition of epilepsy, which is defined by any of the following conditions: (1) at least two unprovoked (or reflex) seizures occurring >24h apart; (2) one unprovoked (or reflex) seizure and a probability of further seizures similar to the general recurrence risk (at least 60%) after two unprovoked seizures, occurring over the next 10 years; and (3) diagnosis of an epilepsy syndrome. An electroencephalogram (EEG) was taken for all children with epilepsy.

Ophthalmological examination including visual acuity, refraction, and fundoscopy was performed in all participants. Visually evoked response was tested in patients whose visual acuity could not be assessed clinically due to inability to follow commands. Flash visual evoked potential was conducted in patients as a screening test. A screening test for hearing assessment was performed by Brawstem evoked response audiometry (BERA) Phone. BERA Phone was performed by MAICO Diagnostic Gmbh MB 11. In it a standard stimulus of 35 dB was used. Headphones were used to give auditory stimulus in BERA Phone. Patients who passed this test were labeled as having normal hearing and those who did not pass this test were subjected to brainstem evoked response audiometry (BERA) test. BERA was conducted by Cadwell machine.

Cognition was evaluated by calculating the social quotient using the Vineland Social Maturity Scale for children younger than 6 years (this is not really cognition, just a social adaptive scale) and intelligence quotient using Malin’s Intelligence Scale for children older than 6 years.

In accordance with the American Academy of Neurology guidelines, a neuroimaging was performed in all cases. In view of resource constraints, a noncontrast computed tomography (CT) scan was performed in children with a clear history of perinatal asphyxia. In all others, or if the initial CT was normal, magnetic resonance imaging (MRI) of the brain was advised.

RESULTS

Total 167 patients were identified. Of 167 patients, 2 were diagnosed as homocystinuria, 1 was diagnosed as subacute sclerosing panencephalitis, and 4 were further investigated for inborn error of metabolism as their history revealed regression of milestones. Thus 160 patients between the ages 2 and 15 years were enrolled for study. The majority of the patients were below 5 years (n = 103, 64.4%), whereas only 5 patients (3.1%) were more than 10 years. Most of them were males (n = 116, 72.5%) and belonged to urban population (n = 129, 80.6%). Nearly one-third (34.4%) cases were delivered at home and the rest two-thirds (65.6%) were hospital deliveries. Of 105 hospital-delivered cases, 73 (69.5%) were vaginal delivery and 31 (29.5%) were lower segment cesarian section. Perinatal asphyxia was the most common risk factor of CP (n = 67, 41.9%). A detailed perinatal history with history of delayed cry at birth and neonatal encephalopathy, history of neonatal ICU stay, and seizures were suggestive of perinatal asphyxia.

Other risk factors of CP are neonatal sepsis or meningitis (n = 19, 11.9%), prematurity (n = 15, 9.4%), twins (n = 11, 6.9%), pathological jaundice (n = 8, 5.0%), and kernicterus (n = 3, 1.9%). The etiology of CP could not be identified in 39 cases (24.4%).

The most common motor type of CP was bilateral spastic CP (spastic quadriplegia; n = 69, 43.1%), followed by unilateral spastic CP (spastic hemiplegia; n = 39, 24.4%), bilateral spastic CP with lower limb predominance (spastic diplegia; n = 38, 23.7%), and dyskinetic CP (n = 4, 8.8%).

Of the patients, 52.5% were able to walk unaided with some limitation, 33.8% were ambulatory with external aids, and 13.8% were nonambulatory. More than 50% of patients with bilateral spastic CP, bilateral spastic CP with lower limb predominance, and dyskinetic CP had difficulty in ambulation (GMFCS score ≥3). Unilateral spastic CP fared better with 30% patients having a score of 3 or more. Gross motor function among types of CP is described in Table 1. There was no statistical significance found between GMFCS scores and types of CP.

Table 1

Gross motor function among types of CP

	Bilateral spastic CP (n = 69, 43.1%)	Unilateral spastic CP (n = 39, 24.4%)	Bilateral spastic CP with LL predominance (n = 38,23.8%)	Dyskinetic (n = 14, 8.8%)	Total
Level 1	11, 16%	17, 44%	11, 29%	4, 29%	43, 26.9%
Level 2	22, 32%	9, 23%	8, 21%	2, 14%	41, 25.6%
Level 3	12, 17%	3, 8%	7, 18%	2, 14%	24, 15%
Level 4	13, 19%	7, 18%	6, 16%	4, 29%	30, 18.8%
Level 5	11, 16%	3, 8%	6, 16%	2, 14%	22, 13.8%

LL = lower limb

Epilepsy was present in 55.6% (n = 89) of enrolled patients. Generalized tonic clonic seizure was the most common type of seizure (n = 53, 59.6%), followed by focal seizures (n = 24, 26.9%), generalized myoclonic seizures (n = 4, 4.5%), and epileptic spasm (n = 8, 9%). EEG could be carried out in 82 of 89 children with epilepsy. The abnormalities seen were generalized epileptiform discharges (n = 32, 20%), focal discharges (n = 30, 18.8%), and hypsarrhythmia (n = 8, 5%). The EEG was normal in 7.5% (12) patients.

Twenty-five (15.6%) cases had no visual fixation. Of the remaining 135 cases, 26 had squint (esotropia in 22 [16.3%] and exotropia in 4 [2.9%]) on clinical examination. Refraction was carried out for 130 patients because 30 patients did not come for follow-up visit. Twenty-six (20%) cases had hypermetropia, 10 (7.7%) cases had myopia, whereas 93 (71.5%) cases were emmetropic. One patient had hypermetropia in one eye and myopia in another eye. Optic atrophy was present in 13 (8.1%) children, being unilateral in 4 (2.5%), and bilateral in 9 (5.6%).

Hearing loss was present in 8% of patients and speech problems were present in 19.3% patients.

Of the patients with CP, 87.5% had some degree of intellectual disability (ID). ID was common in both dyskinetic (92.8% of all dyskinetic cases) and bilateral spastic CP (86.9% of all bilateral spastic cases).

Of the 160 cases, 6 (3.8%) cases had borderline global developmental delay (GDD) and ID each; 51 (31.9%) and 25 (15.6%) cases had mild-to-moderate GDD and ID, respectively; and 37 (23.1%) and 15 (9.3%) cases were of severe-to-profound GDD and ID, respectively.

Microcephaly was seen in 77 (48.1%) cases. Chewing, swallowing, and drooling problem was present in total 39.4% cases. Recurrent vomiting was present in 14.4% of cases.

Neuroimaging was conducted for 151 cases. MRI was performed in 35 cases. Neuroimaging was normal in 15% patients as confirmed by MRI. Neuroimaging findings in various patients are described in Table 2.

Table 2

Neuroimaging findings

Neuroimaging findings (n = 151)	Number (%)
Normal	24 (15)
Cerebral atrophy	46 (28.8)
Encephalomalacia	25 (15.6)
Periventricular leukomalacia	14 (8.8)
Basal ganglia lesion	14 (8.8)
Cerebral infarct	13 (8.1)
Hemorrhage	8 (5.0)
Porencephalic cyst	3 (1.9)
Malformation	4 (2.5)

ID was the most common comorbidity across all subtypes of CP. Epilepsy was the second most common complication in all groups, seen more frequently with bilateral spastic CP than unilateral spastic CP. Hearing and speech difficulties were significantly associated with dyskinetic form of CP (P value being 0.001 and 0.022, respectively). Visual impairments including fixation defects, squint, and refractive errors were most common in bilateral spastic CP whereas optic atrophy alone was more common in dyskinetic CP. The distribution of various comorbidities among types of CP is given in Table 3.

Table 3

Comorbidities in various subtypes of CP according to GMFCS.

		Bilateral spastic CP	Unilateral spastic CP (n = 39, 24.4%)	Bilateral spastic CP with LL predominance (n = 38, 23.8%)	Dyskinetic	P value
Epilepsy		45 (65.2%)	20 (51.3%)	17 (44.7%)	7 (50.0%)	0.181
Hearing problem		8 (11.6%)	0 (0.0%)	1 (2.6%)	4 (28.6%)	0.001
Speech problem		18 (26.1%)	6 (15.3%)	2 (5.3%)	5 (35.7%)	0.022
Vision problem	Visual fixation	16 (23.1%)	1 (2.6%)	6 (15.8%)	2 (14.2%)	0.044
	Squint	14 (20.3%)	4 (10.3%)	6 (15.8%)	2 (14.3%)	0.592
	Refractive error	40 (28.9%)	11 (14.1%)	17 (22.4%)	6 (21.4%)	0.029
	Optic atrophy	7 (10.1%)	1 (2.5%)	3 (7.9%)	2 (14.3%)	0.439
ID		60 (86.9%)	25 (64.1%)	30 (78.9%)	13 (92.8%)	0.021
Feeding problem	Chewing and swallowing, and drooling	42 (60.8%)	11 (28.2%)	18 (47.3%)	5 (35.7%)	0.009
	Recurrent vomiting	8 (11.6%)	8 (20.5%)	4 (10.5%)	3 (21.4%)	0.448

LL = lower limb

DISCUSSION

Of 160 patients enrolled in our study, 72.5% were males with a male to female ratio of 2.6:1. This is in line with previous studies, where male gender has been identified as an independent risk factor for CP and adverse neurodevelopmental outcomes.[5678] In their studies on CP, Evans et al.[7] and Stanley et al.[8] found a male preponderance (58% and 66% of the study population, respectively). Of the children enrolled in a hospital-based study from Delhi evaluating feeding difficulties in children with CP, 76% were males.[9] The higher health-seeking behavior for males as compared to girls probably acts as an additional factor contributing to the higher male to female ratio in studies from India. Sex of a child is an important factor in health care–seeking behavior especially in rural areas, where sons are favored and more valued than in urban areas.[10]

The most common risk factor identified in our study was perinatal asphyxia in 41.9% cases. Previous studies from developing countries report perinatal asphyxia to be a major risk factor of CP, percentage varying from 20% to 46% in different studies.[111213] It is an uncommon risk factor in developed countries like Australia, accounting for only 7%–10% cases of CP.[14] This is reflective of the poor availability and accessibility of maternal and perinatal health care facilities in our country. Prematurity accounted for only 9.4% cases in our study, much less than that reported in Western literature. The higher survival rate of preterms owing to more advanced obstetric and neonatal care in developed countries is probably responsible for this difference. Singhi et al.[15] found birth asphyxia to be the most common cause of CP (45%), followed by postnatal CNS infection (25%), neonatal sepsis (14.6%), kernicterus (21%), and prematurity (13%).[15] Postnatal infections accounted for only 11.9% of patients with CP in this study.

Spastic CP was the most common type of CP in our study, as is seen all over the world.[816] The distribution of clinical subtypes of CP was similar to that reported by previous studies from India[15]; bilateral spastic CP being the most frequent followed by unilateral spastic CP and bilateral spastic CP with lower limb predominance. Developed countries show a preponderance of bilateral spastic CP with lower limb predominance attributable to the higher rate of survival of preterm babies in their setting. In our country, where perinatal asphyxia and hypoxic ischemic encephalopathy (HIE) form the most common etiology of CP, the correlating clinical subtype of bilateral spastic CP is also the most common.

Of the cases, 52.5% were ambulatory without any aides (level 1 and level 2). Of the total cases, 47.5% had severely impaired mobility (level 3, level 4, and level 5) and were dependent on aides or on other persons for mobility. In a study by Himmelmann et al.,[17] 32% cases were at level 1, 29% at level 2, 8% at level 3, 15% at level 4, and 16% at level 5. GMFCS levels 3, 4, and 5 were noticed in 52.2% of total bilateral spastic CP; 50.0% of total bilateral spastic CP with lower limb predominance and 57.1% of total dyskinetic cases had difficulty in ambulation In Himmelman study, age group studied was from 4 to 8 years whereas in this study, age group is 2 to 15 years. There were 38 patients from age 2 to 4 years out of 69 bilateral spastic CP (spastic quadriplegic). As the motor impairment in young children is not that remarked and necessary intervention was carried out on time, motor function disability was not that severe in studied group.

Though CP is described as a disorder of movement and posture, it is the result of an injury to the developing brain. Thus, it effects or impairs various other functions of the brain as well resulting in several comorbidities being associated with it.

In this study, 55.6% of cases had epilepsy. The reported incidence of epilepsy in CP in literature varies from 30% (Hagberg et al. 1996[16]) to 70% (Stanley et al. 1993[18]). Singhi et al.[15] in various studies reported epilepsy to be present in 32%–35.4% children with CP.[19] Epilepsy was present in 65.9% of unilateral spastic CP as compared to 42.6% of bilateral spastic CP in their study. However, we found a higher rate of epilepsy in bilateral spastic CP (65.2%) than unilateral spastic CP (51.3%). Our findings are closer those of Himmelmann et al.,[17] who found epilepsy in 87% of bilateral spastic CP, 34% of bilateral spastic CP with lower limb predominance, 23% of unilateral spastic CP, and 52% of dyskinetic CP. Hadjipanayis et al.[20] reported epilepsy in almost half of the patients with bilateral spastic CP and unilateral spastic CP.

Visual inattention is a well-recognized problem associated with CP. Visual defect in various studies was found to vary from 6% to 60%.[7112122] In this study, 19.2% cases had squint. In various studies squint varied from 16% to 50%.[71121] Hypermetropia was more prevalent in this study as compared to myopia. The study of Kozeiset al.[21] showed that hypermetropia and astigmatism are the most common refractive errors. Optic atrophy was present in 13 (8.1%) cases. In this study, there was statistically significant correlation between absence of visual fixation and refractive error with motor types of CP (P value being 0.044 and 0.029, respectively). Visual fixation was absent in 3 cases (n = 52, 5.8%) of mild GDD/ID, 5 cases (n = 24, 20.8%) of moderate GDD/ID, 6 cases (n = 30, 20.0%) of severe GDD/ID, and 11 cases (n = 22, 50.0%) of profound GDD/ID. Visual fixation was absent in maximum number of cases with maximum mental retardation. Visual fixation in cases of CP has statistical significant correlation with mental retardation (P = 0.0001).

Binocularity and straight visual axis of both the eyes are a function of visual cortex; therefore, with more damage and ID, it is expected that CP children have more squint.

Other comorbidities seen were hearing, speech, and feeding difficulties. Hearing and speech difficulties were significantly associated with dyskinetic, as also reported in most previous studies. The incidence of problems in speech development was much higher in our study (19.3%) as compared to that by Singhi et al.[15] (7.8%). Feeding difficulties reported were difficulties in chewing and/or swallowing, excessive drooling (39.4%), and recurrent vomiting (14.4%). Gangil et al.[9] reported an incidence of feeding problems in 50% of children with CP (chewing difficulty in 11% and swallowing problems in 19% and drooling in 20%). In the study by Gangil et al.,[9] feeding problem was more as compared to this study due to more cases of bilateral spastic CP (75%). The percentage of children with microcephaly in our study was 48.1%, less than reported by Venkateswaran and Shevell[23] (58%).

ID was the most common comorbidity in our study. Of the patients, 47.5% had mild-to-moderate mental retardation and 32.6% had severe-to-profound mental retardation. Previous studies from both developed and developing countries have also found mental retardation to be present in more than two-thirds of children with CP. ID was also seen in majority of patients with dyskinetic CP.

In accordance to American Academy of Neurology guidelines recommending neuroimaging in all cases of CP to define etiology, predict pattern, and timing of injury and to decide severity of injury, we attempted neuroimaging (CT in 116 cases and MRI in 35 cases) in all patients but 9 cases did not come for follow-up. Similar to previous studies, imaging abnormalities were detected in 85% of our patients. The most common abnormalities were cerebral atrophy and encephalomalacia, patterns known to be associated with perinatal HIE in term neonates. The frequency of periventricular white matter injury (PVWMI) was much lower (8.8%) than that found in Western literature (19.2% by Towsley et al.,[13] study conducted in Canada), indicating a lower survival of preterms in our setting than in developed countries. In a systematic review conducted by Krägeloh-Mann and Horber[24], the frequency of PVWMI was found to be as high as 56%. In this study, MRI was performed for all patients with kernicterus, and globus pallidus changes were noted in all.

CP is a common condition seen in developing countries and not much literature is available for developing countries; thus, this study gives a perspective for CP in such countries. This study focuses on associated disabilities of CP also; thus, it helps understand the correlation of severity of motor disabilities and its type with other comorbidities.

This study was carried out on 160 children with CP. Though the study has conveyed us many important information but if the study had been conducted on more number of children, it could have given us more information. The study was a cross-sectional study and thus the cases were not followed up over time and the course of disease and progression/regression of various disabilities cannot be commented upon.

CONCLUSION

The risk factors and clinical spectrum of CP in our country are different from that seen in developed countries. There was a higher male to female ratio, indicative of higher health-seeking behavior for male children and male gender being an independent risk factor for CP. Perinatal asphyxia is a major risk factor for CP, whereas the survival rate of preterm babies is still low. Bilateral spastic CP, which correlates with the severest insult to the developing brain, was the most frequent neurologic subtype of CP. There is an urgent need to improve the maternal and neonatal health facilities making them easily available and accessible to all.

The most common comorbidity was ID followed by epilepsy in all subtypes of CP. Hearing and speech impairments were common with dyskinetic CP whereas visual defects were more common with bilateral spastic CP. A knowledge of the common comorbidities associated with the relevant subtype of CP helps to anticipate these problems, so that they can be timely diagnosed and appropriately managed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.