Relative frequencies of neurological disorders in Northwestern Nigeria: A retrospective study.

Background: Early diagnosis and management of diseases takes a center stage in the control and prevention of chronic debilitating disorders. It also plays a prominent role in ensuring that patients are better equipped on how to deal with the disease burden. One reliable means of achieving this objective is to retrospectively study the frequency of common diseases. Materials and
Methods: This was a retrospective study conducted between January 2010 and December 2014. Relevant data were extracted from patients' case folders. Adjustment to correct for potential biases such as multiple admissions and secondary diagnosis using a covariate on admission data was made to correct for systematic error. Information obtained was analyzed for frequency and distribution.
Results: The mean age of the patients was 44.9 years (standard deviation ± 16.7), with an age range of 15-99 years. The most common neurological disorder was stroke which accounted for 21.3%, followed by spinal cord compression syndromes (20.8%), epilepsy (17.3%), parkinsonian syndromes (8.9%), headaches (7.1%), and bacterial meningitis (5.2%). The highest number of cases of neurological disorder occurred within the age group of 45-54 years.
Conclusion: The outcome of this study revealed that stroke and spinal cord compression syndromes were the most common neurological disorders in our center. It also showed that individuals within their productive age (50-54 years) were more affected. Given the present state of constrained resources, coordinated efforts at the institutional, state, and federal government levels are essential to encourage prioritization, funding, and implementation of effective health-care delivery system.

INTRODUCTION

As populations are aging and the number of elderly individuals is exponentially increasing, there are a growing number of people in need of long-term care. Therefore, the need for evaluation, assessment, and updating knowledge on frequency and control of chronic disabling diseases becomes more important. In addition, as countries in developing societies confront the effects of change in the burden and epidemiological transition of chronic noncommunicable diseases, there will be an increased need for up-to-date assessment of nonfatal health outcomes and exploration of the implications of growing number of individuals with chronic diseases.[1] Moreover, as the expense of health-care delivery in Nigeria rises toward unsustainable levels, there is a need for cost justification in which the prevalence, morbidity, and disability of the diseases we manage are becoming critical to the continued allocation of available meager resources toward neurological care. This is so because the outcome of huge financial investments in cardiovascular diseases in developed societies in the past has yielded significant benefits for such diseases, dramatically increasing overall health and survival.[1]

Although mortality is the usual primary outcome measure in many research studies, the cost and societal impact of diseases are largely determined by the disability they cause; this is particularly true of neurological disorders since the years lost to disability from neurological and musculoskeletal disorders are greater than that of all other categories of diseases.[23] After comprehensive review of the nationwide and world literature, we chose for discussion the most prevalent and commonly managed neurological diseases in the region, focusing on those prevalence and incidence estimates we considered the most reliable. Using this method, stroke, compressive myelopathies, epilepsy, movement disorders, and headache emerged as the most common disorders and are highlighted below. We excluded many other disorders that are not as common and disorders with mixed etiologies to be as conservative as possible, despite the fact that these diseases were managed in our neurology unit.

MATERIALS AND METHODS

This was a retrospective study conducted in the neurology unit of Usmanu Danfodiyo University Teaching Hospital Sokoto (UDUTHS) over the period of 5 years (between January 2010 and December 2014). Relevant data were extracted from patients' case folders; data were validated using Microsoft Excel. Relevant data were analyzed. Adjustment to correct for potential biases such as multiple admissions and secondary diagnosis using a covariate on admission data was made to correct for systematic error. Information obtained was analyzed for frequency and distribution. Analysis of data was carried out using the “Statistical Package for the Social Sciences” (SPSS) program for Windows version 23.0 (SPSS Inc., Chicago, IL, USA). Mean and standard deviation (SD) were used to describe quantitative variables. Bivariate analysis was carried out using Pearson's Chi-square or Fisher's exact test for categorical variables. Student's t-test was used to compare the means of continuous variables.

RESULTS

There were a total of 2537 cases of neurological disorders managed in the unit during the study period. Females accounted for 52.7% and males were 47.3%, with a female-to-male ratio of 1.1:1 [Figure 1]. The mean age was 44.9 years (SD ± 16.7), with an age range of 15–99 years. The common neurological disorders were stroke (21.3%), spinal cord compression syndromes (20.9%), and epilepsy (17.3%) [Table 1]. The highest number of cases of neurological disorder occurred within the age group of 45–54 years [Table 2]. Correlation of Age and sex showed predominance of neurological diseases among young females [Figure 2]. Distribution of neurological disorders by sex, showed predominance of neurological diseases among females [Table 3], the role of sex was further evaluated by sex and age correlation [Table 4].

Figure 1

Sex distribution of neurological diseases among patients

Table 1

Frequency of neurological disorders

Diagnosis	Frequency (%)
Stroke	540 (21.3)
Cord compression syndrome	529 (20.8)
Epilepsy	438 (17.3)
Parkinsonian syndromes	225 (8.9)
Headaches	181 (7.1)
Bacterial meningitis	131 (5.2)
Peripheral neuropathy	107 (4.2)
Cranial neuropathy	87 (3.4)
Encephalopathies	54 (2.1)
Dementia	50 (2)
Muscular dystrophy	44 (1.7)
Myasthenia gravis	33 (1.3)
Intracranial tumors	28 (1.1)
Noncompressive myelopathies	22 (0.9)
Other movement disorders	19 (0.7)
Motor neuron disease	13 (0.5)
Chronic inflammatory demyelinating polyneuropathy	7 (0.3)
Hematoma	8 (0.3)
Cerebral palsy	6 (0.2)
Hydrocephalus	6 (0.2)
Congenital anomalies	5 (0.2)
Cerebella ataxia	4 (0.2)
Total	2537 (100)

Table 2

Age distribution of neurological disorder

Age group	Frequency (%)
15-24	345 (13.6)
25-34	371 (14.6)
35-44	405 (15.9)
45-54	673 (26.6)
55-64	425 (16.8)
65-74	195 (7.7)
75-84	88 (3.5)
85-94	35 (1.3)
Total	2537 (100)

Figure 2

Age and sex distribution of neurological diseases among patients

Table 3

Distribution of neurological disorder by sex

Diagnosis	Female	Male	Total
Stroke	269	271	540
Cord compression syndromes	253	276	529
Epilepsy	356	82	438
Parkinsonian syndromes	8	217	225
Headache	151	30	181
Bacterial meningitis	76	55	131
Peripheral neuropathies	29	78	107
Cranial neuropathy	50	37	87
Encephalopathies	32	22	54
Dementia	29	21	50
Muscular dystrophies	3	41	44
Myasthenia gravis	0	33	33
Intracranial tumors	21	7	28
Noncompressive myelopathies	20	2	22
Other movement disorders	16	3	19
Motor neuron diseases	0	13	13
Subdural hematoma	2	6	8
Chronic inflammatory demyelinating polyneuropathy	7	0	7
Cerebral palsy	6	0	6
Hydrocephalus	6	0	6
Congenital anomalies	0	5	5
Cerebella ataxia	4	0	4
Total	1339	1198	2537

Table 4

Cross tabulation by age and sex among neurological patients

Age group	Female	Male	Total
15-24	342	3	345
25-34	360	11	371
35-44	321	84	405
45-54	136	537	673
55-64	76	349	425
65-74	65	130	195
75-84	33	55	88
85-94	6	29	35
Total	1339	1198	2537

DISCUSSION

The highest frequency of neurological disorders observed in the 45–54 years' age group was lower than the frequency found in the 50–60 years' age group reported in a study in Ghana,[4] but the mean age of 44.9 years in this study correlated well with the study in Cameroon.[5]

Stroke

In this study, stroke is rated as the most common neurological disorder which corroborated findings of a study from the southern part of the country[6] and earlier study in this region by Owolabi et al.[7] The mean age of 56.85 years, SD ± 14.40, is similar to the mean age of 58 years reported by Divyant and Amit[8] in a study on clinical profile and risk factors among 140 stroke patients in a tertiary care hospital in Bareilly; it also corresponded well with the mean age of 57 years reported by Manorenj et al.[9] and findings in other studies in developed[10] and developing countries.[1112] Therefore, this study supported previous hospital- and community-based studies that reported the incidence and prevalence of stroke among both blacks and nonblacks. More importantly, this study found trends toward increasing stroke incidence among relatively young individuals, a finding that is of great public health significance.

Epilepsy

The female preponderance was observed in an earlier study from southeast Nigeria.[10] The average age of patients was 35.8 years with SD ± 9.6 and an age range of 24–72 years. This figure did not correlate well with findings by Kora et al. among patients with posterior circulation stroke in a tertiary care center in southern India.[11] The study also revealed that the peak age prevalence occurred within the age group of 30–39 years which constituted 58.2%, followed by the age group of 20–29 years which constituted 22.6% of all cases. Finding in this study supported report of International League Against Epilepsy Commission on epidemiology, that epilepsy is a common neurological disorder affecting about 65 million people in the world,[13] and approximately 80% of cases occur in developing countries with little or no access to medical facilities or treatment.[14] The burden of and the global socioeconomic costs afforded by epilepsy are enormous, and its deleterious effect on psychological, cognitive, and social functioning on those who are affected is often substantial and devastating.[15]

Compressive myelopathies

The male preponderance of tuberculosis of the spin in this study substantiated differential sex hospital attendance pattern in the region of the study, as women often require permission of their husbands to access health care in a hospital environment, as alluded to in some other previous studies.[1617181920] Pott's disease is one of the major causes of compressive myelopathies in developing countries; the disease is chronic, debilitating, and associated with long-term sequelae, such as pressure sore, deep venous thrombosis, and risk of pulmonary embolism.[21] The second common compressive myelopathy in this study is cervical spondylosis. The mean age of affected people in this study was 52 years, which correlated well with earlier studies by Pallis et al. who found that cervical spondylosis was a disease of the elderly affecting mostly those over 50 years.[22] In a related development, Ahmed et al. found that the maximum number of cases (60%) of cervical spondylosis among patients in Bangladesh was in the age group of above 50 years.[23]

Movement disorders

The mean age of 51.5 years among patients with secondary parkinsonism in our study was similar to 51.4 years of secondary parkinsonism reported by Femi et al.[24] in an earlier study in this region. It is also similar to what was reported in southwestern Nigeria by Osuntokun and Bademosi.[25] In addition, the mean age of our patients corroborated what was reported in other nations.[262728] Male preponderance in our study was reported in other studies though the gender proportion in our study is much higher than earlier studies in the country. This may be accounted for by methodological differences between the studies; our study population was all patients with movement disorders.

Headaches

The female preponderance of headache found in our study is similar to earlier studies that cut across cultures and geographical locations,[2930313233] including a cohort study in our center.[34] Possible mechanisms mentioned include hormonal influence and factors related to health-seeking behavior of female gender, particularly for headache disorders.[35]

CONCLUSION

This study revealed that stroke and spinal cord compression syndrome are the most common neurological disorders in our center. It also showed that individuals within their productive age (50–54 years) are more commonly affected. Therefore, given the present state of constrained resources and competing priorities, coordinated efforts at the individual, institutional, organizational, local, state, and federal government levels are essential to encourage prioritization, funding, and implementation for the above initiatives. Subspecialty organizations and individual neurologists and neuroscientists must work together to coordinate their advocacy efforts. It is important to note that the very future of the neurological sciences and the patients we manage is now at stake, and the welfare of generations yet to come hangs upon the success of our efforts. This study serves as a key component to the policy-makers and planners to plan well in establishing policies and resource allocation, as well as supplying of adequate diagnostic facilities.

Recommendations

Given the resource-limited setting in developing countries and the cost of brain disorders, which are frequently chronic and sometimes relapsing, greater emphasis needs to be placed on early detection, effective treatment, and early prevention

In view of the relevance of determining the prevalence of disorders of the brain, there is need for concerted effort by all stakeholders toward advocacy, through the provision of education, publications, consultation, and evaluation services. This is particularly critical as some of these vulnerable patients are unable to advocate for themselves

Private–public partnerships should be encouraged to promote novel drug development and to rapidly bring treatments to patients with brain disorders

Efforts to remove hurdles to research must be supported at governmental level, such as removing inappropriate regulations and bottlenecks within the system that would facilitate implementing faster and simpler processes for approval and governance of translational research.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.