ABSTRACT

Background

Neurological disorders constitute a major burden of disease worldwide. The highest incidence and prevalence of these disorders are in the developing countries where the number of neurologists is lowest. The world’s population is aging and life expectancy is projected to rise with gains of 10 years or more in sub Saharan Africa by 2020.Although infectious diseases still persist in this region, non-communicable diseases (NCDs) seem to be very prevalent.

Aim

To study the pattern of neurological disorders among geriatric patients (aged 60 years and above) in the medical wards of the University of Port Harcourt Teaching Hospital (UPTH).

Methods

A four years (June 2002 and May 2006) retrospective analysis of the medical records of all geriatric patients managed in the medical wards of UPTH with a discharge diagnosis of a neurological condition was done.

Results

There were 1138 geriatric patients admitted into the medical ward over the study period, constituting 41.6 % of all the medical admissions over the same period
Geriatric patients with neurological disorders numbered 367 (32.2% of geriatric admissions). Stroke accounted for 78.7% of all the neurological disorders. Neurological infections like meningitis, Pott’s disease, tetanus and rabies constituted 5.2% of neurological admissions. Another 5% were admitted for neurodegenerative conditions. Geriatric patients with neurological disorders who died were 137, giving a mortality of 37.35%. Stroke caused death in 115 patients (83.9% of all deaths from neurological disorders)

Conclusion

Stroke constitutes a major neurological burden in geriatric population of patients seen in UPTH. Neurodegenerative disorders, Potts disease and meningitis also contribute significantly to this burden.

Key words: Developing country, Geriatric population, Nigeria, Neurological diseases

Introduction

Les affections neurologiques constituent un fardeau important de la maladie dans le monde entier. L’incidence et la prévalence de ces maladies sont des plus élevées dans les pays en voie de développement où le nombre de neurologues est le plus bas. La population du monde vieillit et on projette que le gain de l’espérance de vie est estimé à 10 ans ou plus en Afrique subsaharienne d’ici 2020. Bien que les maladies infectieuses persistent toujours dans cette région, les maladies non-transmissibles (NCDs) semblent être très répandues.

Objectif

Afin d’étudier es aspects des affections neurologiques parmi les patients gériatriques (âgés 60 ans et plus, une étude a été menée l’hôpital universitaire de of Port Harcourt Teaching Hospital (UPTH).

Méthodes

Une analyse rétrospective de quatre ans (juin 2002 et mai 2006) des dossiers médicaux de tous les patients gériatriques hospitalisés à l’UPTH avec un diagnostic de maladie neurologique a été réalisée.

Résultat

1138 patients gériatriques ont été sélectionnés au cours de la période d’étude, constituant 41.6 % de toutes les admissions médicales. Les patients gériatriques neurologiques représentaient 367 cas (32,2%). Les accidents vasculaires cérébraux (AVC) constituaient 78,7% de tous les troubles neurologiques. Les infections neurologiques : méningite, maladie de Pott, tétanos et la rage ont constitué 5,2% des admissions. 5% relevaient des maladies neurodégéneratives. Les patients gériatriques décédés étaient au nombre de 137 (37.35%.) Les AVC ont causé la mort de 115 patients (83,9% de toutes les décès)

Conclusion

Les AVC constituent un fardeau neurologique important dans la population gériatrique des patients vus au UPTH La maladie de Pott et la méningite y contribuent également de manière significative.

Mots clés: Gériatrie, maladies neurologiques, Nigéria

INTRODUCTION

Neurological disorders constitute a major burden of disease worldwide (14). This is more so in the elderly patients in whom non communicable conditions like stroke and neurodegenerative diseases predominate. In the developing countries, neurological infections like meningitis and tetanus also contribute significantly to the high burden of disease (6). Worldwide, one out of nine deaths results from a disorder of the nervous system (1). Moreover, stroke and other cardiovascular diseases are likely to increase substantially over the next few decades in lower-income countries(3). This is because of their expected health and demographic transition, adding to the current infectious and poverty-related disease (21).

The highest incidence and prevalence of disorders of the nervous system are in developing countries, where the number of neurologists is lowest (1, 2). Furthermore, there has been enough evidence showing that, in the years to come, policy-makers and health-care providers in developed and developing countries alike may be unprepared to cope with the predicted rise of the prevalence of mental and neurological disorders and the disability associated with them (23). The world’s population is ageing and life expectancy is projected to continue to rise, with gains of 10 years or more in sub-Saharan Africa by 2020 (1). Although enormous challenges still persist in the control of infectious diseases in sub-Saharan Africa, the emergence of non communicable diseases especially stroke and other cardiovascular diseases has added to the threats on the health of adult Africans (12). The health transition has therefore led to what has been known as a ‘double burden of disease’ for the developing world: first the ‘unfinished agenda’ of the infectious diseases (particularly among the young) and second the ‘emerging agenda’ of non communicable diseases particularly cerebrovascular diseases and malignancies.

This paper is a study of the pattern of neurological disorders amongst geriatric patients (aged 60years and above) admitted into the medical wards of University of Port Harcourt Teaching Hospital (UPTH). It also sets out to determine the current burden of such diseases in this age group and to assess the mortality rates from neurological disorders among this age group.

METHODS

Retrospective data was obtained from the ward registers and the medical records department for all geriatric patients (aged 60 years and above) managed in the medical wards of the University of Port Harcourt Teaching Hospital between June 2002 and May 2006. The University of Port Harcourt Teaching Hospital serves as the main referral centre for Rivers State and neighbouring States of Abia, Akwa Ibom, Bayelsa and Imo States, all in the Niger Delta region of Nigeria.

Data extracted included age, sex, diagnosis and outcome of treatment. Diagnosis of most cases was clinical. In the study period covered, there were no facilities for electrodiagnostic procedures such as nerve conduction studies, electromyography and electroencephalography. Only very few patients with cerebrovascular accident and other intracranial pathologies had computer tomography scan or magnetic resonance imaging performed on them as most could not afford to pay for it. Diagnosis of stroke subtype was often done with the WHO criteria for acute stroke syndrome (16). All neurological admissions were analyzed and classified in accordance with the ICD- 10 (22). Data was analyzed using the statistical package SPSS 11.

RESULTS

There were 1138 patients aged 60 years and above admitted into the medical wards over the study period out of 2736 total medical admission. This constitutes 41.6% of all medical admissions over the same period. Geriatric patients with neurological disorders were 368, representing 13.5% of all medical admissions and 32.2% of total geriatric admissions respectively. The age and sex distribution of all admitted geriatric patients is as shown in Table I. There were 197 males and 170 females admitted with neurological disorders, giving a male to female ratio of 1.2:1. There was a decreasing frequency of geriatric admissions for neurological disorders with increasing age.

Stroke, the commonest cause of geriatric neurological admission, accounted for 289 (78.7%) cases. Hypertensive encephalopathy was responsible for 23 (6.3%) admissions. Neurodegenerative disorders like Parkinsonism and dementia constituted 5% of all geriatric admissions. There were nine cases of dementia, clinically diagnosed following neuropsychological assessment as Alzheimer’s disease in two patients, vascular dementia in another two while five patients had senile dementia. Pyogenic meningitis and transient ischemic attack accounted for 5 (1.4%) admissions each. The total mortality from neurological disorder among geriatric patients during the period was 137(37.3% of all neurological disorder). Stroke constituted the highest mortality with a total of 115 (83.9%) deaths. Of these, ischaemic stroke had a case fatality rate (CFR) of 37.2% while intracranial heamorrhage alone and that with subarachnoid extension had a CFR of 64% and 57.1% respectively (Table II). Subarachnoid heamorrhage (SAH) had a CFR of 25%. Some neurological infections like rabies, tetanus, tuberculous meningitis though rare, all
had a CFR of 100% each. Pyogenic meningitis had a CFR of 60 %.( Table II)

DISCUSSION

Stroke is the third most common cause of adult mortality worldwide after ischaemic heart disease and cancer (23). Most of the stroke incidence in developing countries is likely accounted for by the increasing prevalence of conventional risk factors such as hypertension (which increases with age), diabetes, hypercholesterolaemia and smoking as populations adopt a more urbanized lifestyle (4). A high prevalence rate of hypertension (as high as 30.2% in those aged 60-64 years and 44.8% in the age group 65-69 years) has been reported from urban areas of Nigeria (18, 8). Only 33.8% of these patients are aware of being hypertensive and only about 65% of those who are aware are said to be on any form of treatment (8). In a setting like this, the incidence of long term complications of hypertension such as stroke is expected to be high. Stroke accounted for 78.7% of all the neurological disorders in this study. Reports from previous studies in Nigeria and other populations of African descent shows that majority of stroke cases occur as a complication of hypertension (15, 5). A similar high frequency of stroke was also reported by McLigeyo( 13) amongst geriatric admissions at the Kenyatta National Hospital; Kenya. Talabi(19) also reported a predominance of stroke (50.4%) in a 3-year review of neurological admissions into the adult ward of a tertiary centre in Ibadan, South- West Nigeria. The age distribution of geriatric admissions (Table1) shows a decreasing frequency of geriatric admissions with increasing age. This may be a reflection of the general population distribution of adult Nigerians seen in this hospital, or it may suggest a negative relationship on survival between the effect of hypertension and other non-communicable diseases with increasing age (18).
The commonest stroke subtype seen was ischaemic stroke. Diagnosis of stroke subtype was mainly clinical using the WHO criteria for acute ischemic syndrome (10) as facilities for neuroimaging were not in place. Even when computer tomography (CT) scan and magnetic resonance imaging (MRI) became available in UPTH a year ago, they were largely unaffordable. The usefulness of the WHO stroke criteria has been demonstrated in Nigerian patients (16). A diagnosis of ischaemic stroke was made in these circumstances: 1) when the stroke occurred in a state of relative inactivity. 2) In the absence of preceding headache. 3) Absence of vomiting. 4) Absence of post-stroke loss of consciousness; and 5) Presentation with mild to moderately elevated blood pressure as compared with severely elevated blood pressure for heamorrhagic stroke; and/or a past history of transient ischemic attack(s). The distribution of the stroke subtypes seen in this age group is predominantly ischeamic and is in keeping with reports from the general population and other age group (15, 5).

There were 19 cases of neurological infections constituting 5.2% of all geriatric neurological admissions. The commonest infections were Pott’s disease and pyogenic meningitis. Other infections seen were tetanus, tuberculous meningitis, rabies and cerebral abscess. This is in keeping with findings by Chapp- Jumbo( 6) who reported pyogenic meningitis as the commonest cause of neurological infection in the same centre among patient. Tetanus, rabies, tuberculous meningitis, and cerebral abscess, all had a case fatality rate (CFR) of 100%. These cases are also preventable and call for the need for booster doses of tetanus vaccine to be given to the elderly. Improved housing and tuberculosis control programmes might help reduce the incidence of tuberculosis.
Neurodegenerative disorders like Parkinsonism and dementia constituted 5% of all admissions. This could be an under estimation as most of the Parkinson’s disease patients are treated on out- patient basis. There were nine cases of dementia clinically diagnosed following neuropsychological assessment. Two patients had Alzheimer’s disease. Another two had vascular dementia while the other five patients had senile dementia. No neuroimaging study was conducted on any of these patients. The prevalence of dementia in this group was 2.5% which compares favourably with the 2.29% reported from Ibadan, Nigeria (9).

RECOMMENDATION

Of all mortality resulting from neurological disorders, Stroke deaths constituted 83.9 %. with intracerebral heamorrhage recording a case fatality rate as high as 64%. This high mortality is a cause for alarm and further reiterates the need for a preventive strategy in the face of an ever increasing burden on scarce health resources. This could be addressed by improving public knowledge about stroke through health education, encouraging self health monitoring practice (blood pressure and blood sugar checks) and medication compliance. The individual should be encouraged through jingles, radio announcement, bill boards, television advert to attend periodic medical checkup as hypertension is a silent disease. Other risk factors for stroke, for example diabetes mellitus and hyperlipideamia should be periodically checked for. The patronage of prayer houses as an alternative to hospital should be discouraged so that patients could be managed early at the onset of their ill health to reduce mortality. A major responsibility of the healthcare provider is to spend quality time with identified risk group (geriatric) and advise on lifestyle modification like regular exercise ( at least thirty minutes brisk walk daily ), low salt diet, avoidance of smoking and excessive alcohol intake. Emphasis should be made on the benefits of taking grain, fruit, vegetables and legumes, in addition to the need for drug compliance. These have been found to reduce the risk of stroke significantly (7).
Government should provide the necessary incentives and facilities to prevent and manage stroke. These include providing free health services for the elderly as has been done by some state government, equipping hospitals with some infrastructural facilities like CT scan for early evaluation and management of stroke. More neurologists should be trained and stroke units should be established in designated hospitals in different geographical zone of the country for stroke management. These have also been shown in several studies to improve stroke outcome (17, 9).

CONCLUSION

The implication of this study is that major input in healthcare and preventive activities especially in neurological services should be directed at stroke. The need for setting up of a dedicated stroke centre even if at the regional level cannot be overemphasized. There is also a need to intensify effort at adequate monitoring of blood pressure, provision of affordable hypertensive treatment and secondary stroke prevention measure.

TABLE 1 Age-Sex distribution of all geriatric patients

TABLE 2 Distribution of neurological morbidity and mortality