Neurological diseases at the Pediatric Neurology Clinic in a semi-urban Nigerian tertiary hospital

Abstract

Neurological diseases in children may be associated with mortality and long-term morbidity when they recover from acute ailments. The pattern of neurological disorders in an outpatient service may highlight the burden of these diseases. The objective of the present study is to describe the pattern of neurological disorders at the Pediatric Neurology Clinic of Olabisi Onabanjo University Teaching Hospital (OOUTH), Sagamu, Nigeria. A retrospective analysis of consecutive patients in a Pediatric Neurology Clinic of OOUTH, from 1st January 2011 till 31st December 2014, was carried out. A total of 4,476 patients attended the pediatric outpatient unit. Of these, 433 children had neurological disorders with a prevalence of 9.67%. The most frequent pediatric neurological disorders included seizure disorders (37.7%), cerebral palsy (37.7%), and central nervous system infections with complications (6.2%). The subjects with cerebral palsy were the youngest, while the subjects with seizures were the oldest. This study emphasizes that neurological disease contributes substantially to childhood morbidity in a semi-urban African tertiary hospital.

INTRODUCTION

Neurological disorders are characterized by dysfunctions in any part of the nervous system. Factors which contribute to neurological disorders in children include genetic disorders, neurotoxins, hypoxia, infections, and injuries. The neurological disorders in children manifest as impairment of physical, memory, motor, speech, and cognitive functions. The dysfunction caused may result in several chronic problems. These problems may require in-depth understanding by the physicians, caregivers, and parents for better management.

Neurological disorders are most common in sub-Saharan Africa [1-5] and constitute significant cause of chronic morbidity in the pediatric age group worldwide [6]. The management approach of children with neurological disorders is multidisciplinary with a pediatric neurologist playing a pivotal role. The pediatric neurologist is responsible for coordinating the management of children with neurological disorders and the pediatric neurology service is highly demanding and stressful.

Several studies [7-10] have been carried out outside our setting on the pattern of pediatric neurology disorders, which serve as an audit of the epidemiology and clinical patterns of pediatric neurology disorders. To the best of our knowledge, there is a dearth of reports about the pattern of neurological diseases in children attending outpatient departments in developing countries [11]. Although some tidy number of studies have been conducted in other part of Nigeria [4,5,7,8,10], the cultural differences in knowledge, attitude, and practice as related to the etiology and predisposing factors of neurological disorders have made this study relevant to be carried out within our locality, Sagamu; hence the present study. The aim of the present study is to describe the pattern of pediatric neurological disorders at the outpatient department of the Olabisi Onabanjo University Teaching Hospital (OOUTH), Sagamu, Nigeria. It is expected that this local study will provide an understanding of the trends and characteristics of neurologic disorders in children which will assist in designing and implementing preventive healthcare strategies.

MATERIALS AND METHODS

This study design is retrospective, involving the review of medical records of all consecutive pediatric patients with neurological disorders attending the Pediatric Neurology Clinic at OOUTH, Sagamu, Nigeria. The study duration was 4 years between 1st January 2011 and 31st December 2014. The data retrieved from these patients’ medical records included the patient age at first contact, sex, and diagnosis.

The Pediatric Neurology Clinic at OOUTH takes place on Mondays. Patients are seen by a consultant pediatrician assisted by pediatric registrars. The source of new patients at the clinic are by self-referrals as well as referrals from the pediatric general outpatient department, discharges from admission of the same hospital, and referrals from other health facilities from all over the state, and also from nearby communities in the neighboring states.

The obtained data were stored and analyzed using Statistical Package for the Social Sciences version 11.0 for Windows (Statistical Package for the Social Sciences Inc, Chicago, IL). The data presentation was as percentages and proportions. Chi-square test was used to test the relationship between categorical variables. The level of significance was set at p < 0.05.

RESULTS

Age and gender distribution of patients

The age and gender distribution of study subjects are shown in Table 1. Of all the 4,476 children seen at the children outpatient unit during the study period, 433 patients (9.67%) had neurological disorders. About three-fifths (62.12%) of the children with neurological disorders were male. Overall, the age of the children with neurological disorders ranged from 1 to 204 months, with a mean of 52.96 (±52.62) months and a median of 33 months. The median age of the male group and that of the female group were 36 months and 24 months, respectively.

Table 1.

Age and gender distribution of patients.

Characteristics	Number	Percentage
Gender
Male	269	62.1
Female	164	37.9
Total	433	100.0
Age range
≤1 year	163	37.6
>1-5years	137	31.7
>5 years	133	30.7
Total	433	100.0

Clinical diagnosis of children with pediatric neurological disorders

Table 2 shows the distribution of the clinical diagnosis among children with neurological disorders. The commonest neurological diseases were cerebral palsy and seizure disorder. These two conditions constituted three-quarters of the cases of neurological disorders. Learning disorder, post-measles neurologic sequelae, sciatic nerve injury, Bell’s palsy, and floppy infant syndrome were infrequently encountered.

Table 2.

Clinical diagnoses of children seen at the Pediatric Neurology Clinic.

Disorder	Number (%)
Cerebral palsy	163 (37.7)
Seizure disorder	163 (37.7)
Unclassified	34 (7.9)
Central nervous system (CNS) infection with neurologic sequelae	27 (6.2)
Speech impairment	12 (2.8)
Microcephaly	5 (1.2)
Attention deficit hyperactivity disorder	3 (0.7)
Autism	3 (0.7)
Duchene muscular dystrophy	3 (0.7)
Erb’s palsy	3 (0.7)
Mental retardation	3 (0.7)
Neural tube defects	3 (0.7)
Cerebrovascular accident	2 (0.5)
Hearing impairment	2 (0.5)
Tetanus	2 (0.5)
Learning disorder	1 (0.2)
Sciatic nerve injury	1 (0.2)
Bell’s palsy	1 (0.2)
Post-measles neurologic sequelae	1 (0.2)
Floppy infant syndrome	1 (0.2)

Demographic characteristics of the major neurological disorders

Seizure disorder, cerebral palsy, and CNS infection with neurologic sequelae as principal diagnoses comprised about four-fifths (81.52%) of the cases. Table 3 shows the ages of children at first contact and gender distribution of patients with major neurological disorders. The subjects with cerebral palsy were the youngest, while subjects with seizure disorder were the oldest. All the major pediatric neurologic disorders have male preponderance. The highest male to female ratio was seen among subjects with CNS infection with neurologic sequelae, while subjects with seizure disorder had the lowest male to female ratio.

Table 3.

Demographic characteristics of major neurological disorders.

Disorder	Mean age, years (SD)	Male:female ratio
Cerebral palsy	2.05 (2.05)	1.9:1.00
Seizure disorder	6.76 (4.86)	1.5:1.00
CNS infection with neurologic sequelae	4.15 (4.94)	2.7:1

CNS = central nervous system; SD = standard deviation.

DISCUSSION

There is an underestimation of childhood neurological disorders and they are often overlooked in developing countries. This may be attributed to the chronicity of the conditions and the multidisciplinary approach required for management. Although the onset of most of the pediatric neurological disorders is acute, most of them have a chronic course resulting in a huge socio-economic burden to the patients and their families. Early identification is important to prevent chronic morbidity and improve quality of life of both patient and family. To enable proper healthcare planning, there is a need for determining the distribution of neurological disorders in developing countries like Nigeria.

The finding of our study supports the fact that neurological disorders are commonly seen in a pediatric setting in developing countries. Of all the 4,476 children seen at the outpatient unit of the OOUTH during the study period, it was observed that the prevalence of neurological disorders was 9.67%. This observed prevalence rate was higher than 6.7% and 3.3% reported by Frank-Briggs et al. [7] among Nigerian children and Kaddumukasa et al. [12] among Ugandan children, respectively. These observed differences across studies are likely due to the variation in the study sample size. A small sample size, as in the present study, is prone to give an exaggerated value of the prevalence rates. The sample sizes in the previous studies by Frank-Briggs et al. [7] and Kaddumukasa et al. [12] were 2,379 and 3,000, respectively. The reported prevalence value from the current study was lower than the 21%, which was also reported by Lagunju et al. [5] among consultations at the pediatric specialist clinics at the University College Hospital, Ibadan.

Our study shows that neurological disorders are more common among male subjects compared to their female counterparts. This supports the finding reported by previous studies in Nigeria [5,8-10] and other regions of the world [11,13]. The reason for male predominance in this study, as well as others, is difficult to explain. However, the reason may be attributed to gender-related health-seeking behavior influenced by the cultural attitude of our population and/or genetic factors. Due to sociocultural reasons, males are brought readily for medical intervention in developing countries [8].

In the present study, the female subjects are younger than their male counterparts at the time of diagnosis of their neurological disorder. However, this observed difference was not statistically significant. The explanation for the observed difference in mean age at diagnosis of neurological disorders between the males and females may be due to the higher concentration of female children with neurological disorders within the younger age group.

Children who are 5 years of age or less constituted more than two-thirds of the cases seen in the present study. This finding is in agreement with that reported by Frank-Briggs et al. [7] among children with neurologic disorders seen in Port Harcourt, Nigeria. The explanation for this is due to the clinical manifestations of neurodevelopmental disorders which is more evident around this age group [7]. Another reason for the observation may be due to vulnerability to infection by children in this age category leading to high morbidities and mortalities [7].

The two most common neurological disorders in this study include seizure disorder and cerebral palsy, which constituted about three-quarters of all cases seen. This observation supported the findings of previous authors [5-8,14] that seizure disorder and cerebral palsy contributed significantly to the number of neurological disorders seen in pediatric neurology units. However, while seizure disorder or cerebral palsy was the single most common of the principal diagnoses in the other reports, cerebral palsy and seizure disorder were of equal proportion in this report. The healthcare seeking behavior, which is influenced by the sociocultural attitude, may account for the observed difference. The females are married out in their early teens at a time when their pelvic outlet is still inadequate and also they tend to have their babies at home in some of our communities. This predisposes these young girls to obstetric complications during the delivery and perinatal periods which are risk factors for increased incidences of perinatal asphyxia and consequent cerebral palsy. Similarly, majority of deliveries in developing countries like Nigeria is conducted by unskilled traditional birth attendants or by self-help at home or in faith homes in the rural areas and even in some of the urban cities. These practices also predispose to increased risk factors through increased rate of perinatal asphyxia and consequent cerebral palsy. This high prevalence of seizure disorders recorded in the current study may be due to improving awareness that seizure is a medical condition which can be treated in contrast to previous belief that it is caused by evil spirit manipulation and witchcraft attacks. Regular health education of care giver and parents during clinic attendance could be responsible for increased awareness with these parents acting as informants in the society.

CNS infections with its associated complications also contributed significantly to the neurological problems observed in this study. Some of the contributory factors which make the reduction of CNS infections in our society difficult include lack of medical personnel and preference for unorthodox treatments like spiritual healing. The routine administration of childhood immunization has diminished the incidence of these infections in the developed world markedly.

Although preventable causes are responsible for the majority of neurological disorders seen in children in this part of the world [15], genetic disorders also contribute to the pattern of neurological disorders seen in our center. In the current study, congenital CNS anomalies accounted for a small proportion of childhood neurological disorders seen.

Making definitive diagnosis was quite challenging in some children in the current study. About one-twelfth (7.85%) of the patients with neurological disorders had unclassified diagnosis because of financial constraints which make it difficult for them to pay out of pocket for all requested investigations. In resource-limited countries including Nigeria neurology as a pediatric subspecialty rarely attracts attention and priority in the cramped health budget. The lack of comprehensive insurance cover in addition to the cost of necessary investigations contributed to the burdens of the already disadvantaged families. In our setting, metabolic screening for genetic disorders is not possible. It must be acknowledged that the spectrum of neurological disorders presented in this study could have been influenced by the investigative facilities available. It is likely that some type of neurological disorders could have been under-represented because of non-availability of facilities for detailed neurological diagnosis.

The findings of age-related trends in which youngest and oldest age groups were diagnosed with cerebral palsy and seizure disorder, respectively, may suggest that more children with cerebral palsy tend to default from follow-up visits compared to children with seizures. It is not surprising to find parents defaulting from follow-up clinics after few visits, which have been reported by previous authors and are due to the poor state of facilities for the rehabilitation of children with cerebral palsy in our hospital [16]. On the contrary, meaningful control of seizure can be achieved in children with seizure disorder by proper choice of anticonvulsants, thereby encouraging parents to continue follow-up visits.

The finding of three children aged 7-13 years with post-neonatal tetanus in this study is noteworthy of discussion. The proportion of 0.5% reported in the current study is comparable with 0.6% reported by Animasahun et al. [17] among post-neonatal patients in Lagos. This observation reinforces the importance of administration of booster doses of tetanus toxoid at primary and secondary school entry as part of the routine immunization schedule within our community. Therefore, the school health program should be strengthened to ensure full immunization coverage for all pupils.

The retrospective nature and the small number of cases in the current study are limitations. Despite these limitations, there was a demonstrable trend in the prevalence and clinical pattern of major neurological disorders seen among children attending a pediatric neurologic clinic in a semi-urban area. The findings from the present study demonstrated that there is a similarity in the trends of neurological disorders seen among children in a semi-urban tertiary hospital in Nigeria with that of the majority of settings within tropical countries and globally. Cerebral palsy and seizure disorder were the commonest neurological disorders encountered among the studied children.

CONFLICT OF INTEREST

The authors have no conflicts of interest to declare.

FUNDING

Self-funded.

ETHICAL APPROVAL

The Ethics and Review Committee of OOUTH granted the ethical approval for the study. The study is a retrospective (record-based) case-control study. No names were used for data collection. Participants’ consent is not required according to the approved research guidelines of (OOUTH), and confidentiality was ensured at all levels.