INTRODUCTION

Cerebral palsy (CP) is a group of disorders of movement and posture arising from a non-progressive damage to a developing brain characterised by motor disorders which is often accompanied by disturbance of sensation, cognition, communication, perception, behaviour, and seizure disorder (24). CP is the most common cause of physical disability seen in children. It affects 3.6 per 1, 000 children (33). Despite all interventions, the overall prevalence remains the same in developing countries such as Nigeria (5,11,20).

Generally, malnutrition is a common problem in most developing countries and is an important contributor to child morbidity and mortality. Malnutrition is regarded as a very important risk factor that can negatively influence the prognosis of children with chronic neurological disorders like CP (7). Therefore; prevention of this worsening effect lies in early detection, and treatment of malnutrition and its associated risk factors.

The causes of malnutrition in children with CP are multifactorial. These causes include: oromotor dysfunction, inadequate intake, increase losses, and altered metabolism. The oromotor dysfunction results in choking and poor suck effort while inadequate intake is due to amount of food that is spilled, duration taken to feed, and frequency of meals in 24 hours. The increase in loss of food is as a result of food regurgitation, or vomiting. Researchers have documented low caloric intake of children with CP compared with that of apparently healthy age-matched children without CP (26).

The impact of malnutrition on health of children with CP has a wide range of devastating effect on physiology, motor, neurological, and psychological functions. Malnutrition has been shown to impair wound healing and immunity causing increased risk of postoperative complications and diminished immune function (8,12,29). It has been documented that severity of gastro-esophageal reflux is increased in children with CP that have malnutrition (15). The neurological consequences of malnutrition include: diminished cerebral growth, delayed cognitive development, abnormal behaviour, and diminished muscle strength (9,16). The diminished muscle strength results in weakness of the respiratory muscles which leads to cough impairment and thereby predisposing the child to pneumonia (14).

The periodic measurement of nutritional indicators is an important part of routine health care for all children and comparison of these indicators against reference standards or norms serves as a screening tool for health problems. (17). This is because nutritional deficiencies are often common in children with chronic health problems and the fact that malnutrition has a devastating effect on the health of children at a critical stage of their development (10,23).

The present study evaluated the nutritional status in a sample of children with CP attending Child Neurology Service of Olabisi Onabanjo University Teaching Hospital Sagamu. This study hoped to form a basis for the establishment of nutritional surveillance in children with CP with the hope of identifying significantly associated and correctable factors.

METHODS AND SUBJECTS

This was a hospital-based cross-sectional study. The study took place at the Paediatric Neurology Clinic of Olabisi Onabanjo University Teaching Hospital Sagamu. The study subjects were children aged six months to 17 years diagnosed at the unit to have CP. Data was collected between the month of July 2015 and December 2016. Excluded from the study were patients with known chronic illness affecting nutrition other than CP (such as cardiac, renal disease, chromosomal abnormalities, Human Immunodeficiency Virus infection) and congenital malformation that would independently affect food intake (such as cleft lip and/or palate). Also excluded from the study were subjects with severe CP to mitigate effect of loss of muscle mass due to disuse atrophy.

Proposed sample size was determined using the standard statistical formula for prevalence study (4). N = Z² p (1 – p) / a². Where: N = estimated sample size; z = the fraction of area under a normal distribution curve covered by two standard deviations (2SD) on either side of the mean (It is equal to 1.96 (at 95% confidence limits) in a two-tailed test). p = the estimated or known prevalence of severe wasting among children with CP (In this study, the rate of 6.25 % (0.0625) reported by Adekoje TO et al (2) was used; a = the absolute tolerable sampling error (For this study, it was fixed at 10.0% (0.1) around the reference prevalence figure of 6.25%). Therefore, N = (1.96)² x 0.0625 x (1 – 0.0625) / 0.1² = 23.

The sampling technique used was a consecutive sampling approach until the minimum sample size was recruited. Clearance for the study was obtained from the Health Research Ethics Committee of Olabisi Onabanjo University Teaching Hospital, Sagamu with informed consent obtained from each parent/caregiver at the time of recruitment.

Data collection was by the use of a self-administer questionnaire. Each child’s weight was measured to the nearest one decimal place (0.1 kg) using a calibrated weighing scale (Seca®). The length/height was measured to nearest 0.1 cm using infantometer or stadiometer (Seca®) depending on whether the children can stand or not. Body Mass Index (BMI) was obtained using the formula weight divided by the square of height in meters (kg/m²). The head circumference and mid-arm circumference (MUAC) was measured using tape measure (centimeters).

All measurements were taken by the principal investigator using the same instrument throughout the study. Weight-for-age, height-for-age, weight-for-height and BMI z-scores were calculated based on WHO growth standards. The study subjects were classified into different types of under nutrition using their Weight-for-age, height-for-age, weight-for-height and BMI z-scores. Under-nutrition was categorized using the WHO classification as follows: A Z score ≥-2 was no malnutrition, Z score between ≥ -3 and <-2 was moderate acute malnutrition (MAM) – wasting/underweight/stunting/thinness and Z score <-3 was severe acute malnutrition (SAM) – wasting/underweight/stunting/thinness (31). The head circumference was categorized as microcephaly, within normal limit and macrocephaly if z scores <-2, between ≥-2 to +≤2, and >2 respectively (27). The interpretation for the MUAC was according to WHO Child Growth Standards (30) as below in Table I:

The data was subjected to statistical analysis using the Statistical Package for Social Science version 19 software package. The associations for categorical and numerical variables were determined by Chi-square and Student t-test respectively. The level of significance was set at p < 0.05.

RESULTS

The total study sample was made up of 32 children with CP, 21 were males (65.63%) and 11 were females (34.37%). Table 1 shows the distribution of the age groups of the study sample. The highest frequency was for the preschool age group; 17 subjects (53.13%) then 5 – 9 years age group; 10 subjects (31.25%), and 10 – 14 years’ age group; 4 case (12.50%). Only one subject belonged to the ≥15 years age category.

Distribution of malnutrition seen in children with CP according to the z scores for the four indices in relation to the WHO growth charts are shown in Table III. As shown in Table III stunting (height/length-for-age z-score ≥-3.00 to <-2.00) was the most common form of malnutrition prevalent in five of 32 children with CP (15.63%); followed by wasting (weight-for-height/length-for age z-score ≥-3.00 to <-2.00; 12.50%). The least common form of malnutrition were underweight (weight for age z-score ≥-3.00 to <-2.00): 9.38%) and severe obesity (BMI-for-age z-score <-3, 9.38%).

Table IVA and IVB shows the distribution of wasting/stunting and underweight/obesity among study subjects respectively. The prevalence rate of malnutrition was higher among pre-school children with CP compared with their school age counterpart except prevalence of wasting which was higher among the school age group. The prevalence rate of malnutrition was higher among female children with CP compared with their male counterpart except prevalence of underweight which was comparable among both genders. The prevalence of wasting and stunting was higher among children with CP whose birth order was either one or two. On the contrary, underweight and obesity was more prevalent among children whose birth order was more than two. The prevalence rate of malnutrition was higher among children with CP whose family size was greater than two and maternal age >35 years. None of these observed findings reach significant level (p>0.05).

Table V shows the measurements of mid-upper arm circumference of the study subjects. The overall prevalence of severe wasting measured by mid-arm circumference was 46.87%. The mid-upper arm circumference of all the 17 pre-school age study subjects was within normal, while all the 15 school age subjects have severe wasting measured by mid-upper arm circumference. This observed difference was significant (p<0.05).

DISCUSSION

Evaluation of nutrition status and provision of adequate nutrition is an essential component of care in children during illness because of its impact on growth, development, clinical outcomes, and resource utilization and majority of childhood death attributed to malnutrition (23). Therefore, nutritional status should be monitored regularly in children. The aetiology of malnutrition due to illness in children are due to nutrient loss, increased energy expenditure/catabolism, decreased nutrient intake, or altered nutrient utilization (23). These factors are seen frequently in children with CP.

In this study, only 29 out of the 32 (90.62%) of the children with CP studied were anthropometrically normal. In other words, about one-tenth of the children were malnourished. The proportion of malnutrition reported in the current study was much lower than 78.6% reported by May (18) in Yangon Children’s Hospital. The difference might be due to the use of different anthropometric classification in these studies. We used anthropometric z scores to classify malnutrition in this study. Similarly, the reported prevalence rate of malnutrition in the reported study was lower compared to reported prevalence rate from previous studies conducted locally by Okeke and Ojinnaka (21), and Adamu et al (1) (16.3%, and 79.3% respectively) which used same method for nutritional assessment. The lower rate in our study compared to previous Nigeria studies may be due to regional variation of malnutrition according to the National Demographic and Health Survey of Nigeria which reported lowest rate of malnutrition for our zone (28).

The current study showed that stunting is the most prevalent form of malnutrition seen among children with CP. All the five stunted children with CP have moderate stunting with none subjects seen with severe stunting.  These reported prevalence rates in the current study were lower than 52.5% and 52.0% reported by Bansode et al (6) and May et al (18) respectively. The explanation for this observed relatively lower prevalence rate of stunting in children with CP in our study may be that our subjects have less severe forms of CP with little or no difficult feeding. The prevalence rate of stunting in our study is comparable with 17.4% reported by Senbanjo et al (25) among otherwise apparently healthy Nigeria children in Abeokuta, Southwest Nigeria. These data clearly indicate stunting substantially remains a prominent type of malnutrition in both apparently healthy children and children with CP in Ogun State, Nigeria. The higher proportion of stunting in the previous study by Adamu et al (1) may be as aforementioned a result of the regional variation of malnutrition among the paediatric population as shown in the Nigerian Demographic and Health Survey 2013 where Kano, North-West Nigeria, had a significantly higher prevalence of malnutrition compared with Ogun State (28).

From this study the identified key factors that influence occurrence of malnutrition among children with CP were young pre-school age, female gender, birth order of three and above, large family size more than two and maternal age older than 35 years. Children from these families are more likely to be less nourished, and not complete the recommended immunization program making them prone to suffer from common health conditions such as diarrhea as a comorbid condition to their neuromotor problem. The reason for less vulnerability of the older age group could be due to increased access to food compare with the younger children who have total dependence on caregivers for their feeding who might not have enough time to meet the caloric intake of the lengthy mealtimes (18,25). The higher prevalence of stunting among female subjects could have been due to the effect of cultural preference for boys at birth in our society (25).

Underweight has been described as one of the major health problems in developing countries like Nigeria (32). It was observed that using the Z score classification, 9.38% of the subjects studied were underweight. The prevalence of underweight reported by Kakooza-Mwesige et al (13) among Uganda children with CP was about five times higher than the finding of our study. Also, Adamu et al (1) reported a higher prevalence rate of underweight children with CP locally. This observed discrepancy might have arisen from the different populations of children with CP since capabilities of the caregivers to feed their children with CP are incomparable across study. It was observed that children below five years of age and those with family size of three and above are more likely to be underweight. Secondly the other reason might be the socioeconomic strength of the family and plausibly reduced rate of attention particularly in presence of other “normal” siblings.

The second most prevalent form of malnutrition seen in this study was wasting using the weight-for-height-for-age z score classification. The prevalence of wasting in our study was lower than the value reported by Almuneef et al (3) among children with CP in Saudi Arabia (12.5% vs 25%). Wasting has been described to reflect a recent weight loss often due to acute illness that requires an urgent attention and nutritional therapy (3,13). The reason for the higher prevalence in the Saudi Arabia study is likely due to the study population which is sick children with CP admitted for care at Sultan Bin Abdulaziz Humanitarian City (SBAHC), Riyadh Saudi Arabia. The previous study conducted in Kano (1) reported prevalence of wasting which about three times the value reported in our study.

This study used three indicators to reflect wasting, namely weight-for-height-for age z score (12.5%), BMI-for-age z score (0.00%) and mid-upper arm circumference for age (46.87%). The BMI-for-age z score underestimate wasting in these children while the mid-upper arm circumference overestimate wasting among the study subjects. This suggested that either BMI-for-age z score or mid-upper arm circumference for age are less sensitive screening tool to identify wasting in children with CP. Therefore, there is still a need for further research to determine the appropriate cutoffs for predicting wasting as well as their sensitivity and specificity as a nutritional indicator.

To the knowledge of the authors there were no available studies locally following literature search reporting burden of childhood obesity among children with CP (1). Our study reported the prevalence rate of obesity to be 9.38% among children with CP. The prevalence of obesity was higher among the pre-school age group compared with the school age group. Surprisingly, the prevalence rate of 1.9% among apparently healthy pre-school children attending the outpatient unit of Mother and Child Hospital Akure, Southwestern Nigeria reported by Oluwafemi et al (22) was lower compared with 11.76% in our study. Obesity has been reported as one of the fast-growing malnutrition problems worldwide. One can confidently say that the growing burden of obesity will not be a concern among children with chronic disorders such as CP who have feeding difficulties which predispose them to high risks of malnutrition. It is attractive to say that since most of the children with CP are usually born either as small-for-gestational age or preterm which has been documented as a risk for obesity in later life as a result of the thrifty gene programming hypothesis as a possible reason for obesity in the study subject.

It is interesting to mention that while no subject was identified as having overweight when the BMI-for-age z score was used in our study, the rate of overweight by Adamu et al (1) was 6.7%. On the contrary, there was no obese children with CP was identified in the Kano study (1) compared with prevalence rate of 9.38% reported in the present study. Both overweight and obesity constituted over nutrition. This finding corroborated previous study that over-malnutrition is one of type of malnutrition seen in children with CP. Conversely, the prevalence of over-nutrition (overweight and obesity) was higher in the Kano study (1) than in our study.

CONCLUSION

There is double burden of malnutrition among children with CP in our setting due to the presence of both under-nutrition and over-nutrition. This observation calls for a new approach to the nutritional status of children with CP for improved healthcare. There is need to further evaluate BMI and mid-upper arm circumference as indicator of nutrition among children with CP.

Study limitations

Small sample size is a limitation of the study to be able to make conclusive and generalizable remarks. Another limitation is related to the study design; we were not able to conduct serial anthropometric measurements of each of these children with CP that would have provided a better indication of the nutritional status.

IMPLICATIONS

The periodic measurement of nutritional indicators is an important part of routine health care for all children with cerebral palsy This is because nutritional deficiencies are often common in children with chronic health problems and the fact that malnutrition has a devastating effect on the health of children at a critical stage of their development. The contributions described in the manuscript shown that growth monitoring among children with cerebral palsy should be intensified in order to identify malnutrition and feeding problems early to initiate appropriate feeding programs, nutritional counselling and follow-up actions.

CONFLICT OF INTEREST

None to declare

SOURCE OF FUNDING

Self

TABLES

Table I: Mid-Upper Arm Circumference cutoffs to screen under-nutrition

Table II: Socio-demographic characteristics of study subjects

NB: Values in parenthesis are % of number in roll

Table III: Nutritional status of study subjects using weight-for-age, height-for-age, weight-for-height-for-age and BMI-for-age z scores

Note: Values in parenthesis are % of number of respondents; BMI: Body Mass Index

Table IVA: Distribution of wasting and stunting among study subjects according to demographic and selected biological characteristics

NB: Values in parenthesis are % of number of roll total

Table IVB: Distribution of underwe0ght and obesity among study subjects according to demographic and selected biological characteristics

Note: Values in parenthesis are % of number of respondents

Table V: The mid-upper arm circumference and head circumference distribution of the study subjects

Note: Values in parenthesis are % of number of age group total