Identification of genetic risk loci and causal insights associated with Parkinson's disease in African and African admixed populations: a genome-wide association study.

BACKGROUND: An understanding of the genetic mechanisms underlying diseases in ancestrally diverse populations is an important step towards development of targeted treatments. Research in African and African admixed populations can enable mapping of complex traits, because of their genetic diversity, extensive population substructure, and distinct linkage disequilibrium patterns. We aimed to do a comprehensive genome-wide assessment in African and African admixed individuals to better understand the genetic architecture of Parkinson's disease in these underserved populations. METHODS: We performed a genome-wide association study (GWAS) in people of African and African admixed ancestry with and without Parkinson's disease. Individuals were included from several cohorts that were available as a part of the Global Parkinson's Genetics Program, the International Parkinson's Disease Genomics Consortium Africa, and 23andMe. A diagnosis of Parkinson's disease was confirmed clinically by a movement disorder specialist for every individual in each cohort, except for 23andMe, in which it was self-reported based on clinical diagnosis. We characterised ancestry-specific risk, differential haplotype structure and admixture, coding and structural genetic variation, and enzymatic activity. FINDINGS: We included 197 918 individuals (1488 cases and 196 430 controls) in our genome-wide analysis. We identified a novel common risk factor for Parkinson's disease (overall meta-analysis odds ratio for risk of Parkinson's disease 1·58 [95% CI 1·37-1·80], p=2·397 × 10-14) and age at onset at the GBA1 locus, rs3115534-G (age at onset ß=-2·00 [SE=0·57], p=0·0005, for African ancestry; and ß=-4·15 [0·58], p=0·015, for African admixed ancestry), which was rare in non-African or non-African admixed populations. Downstream short-read and long-read whole-genome sequencing analyses did not reveal any coding or structural variant underlying the GWAS signal. The identified signal seems to be associated with decreased glucocerebrosidase activity. INTERPRETATION: Our study identified a novel genetic risk factor in GBA1 in people of African ancestry, which has not been seen in European populations, and it could be a major mechanistic basis of Parkinson's disease in African populations. This population-specific variant exerts substantial risk on Parkinson's disease as compared with common variation identified through GWAS and it was found to be present in 39% of the cases assessed in this study. This finding highlights the importance of understanding ancestry-specific genetic risk in complex diseases, a particularly crucial point as the Parkinson's disease field moves towards targeted treatments in clinical trials. The distinctive genetics of African populations highlights the need for equitable inclusion of ancestrally diverse groups in future trials, which will be a valuable step towards gaining insights into novel genetic determinants underlying the causes of Parkinson's disease. This finding opens new avenues towards RNA-based and other therapeutic strategies aimed at reducing lifetime risk of Parkinson's disease. FUNDING: The Global Parkinson's Genetics Program, which is funded by the Aligning Science Across Parkinson's initiative, and The Michael J Fox Foundation for Parkinson's Research.

Genome-wide Association Identifies Novel Etiological Insights Associated with Parkinson's Disease in African and African Admixed Populations.

Background: Understanding the genetic mechanisms underlying diseases in ancestrally diverse populations is a critical step towards the realization of the global application of precision medicine. The African and African admixed populations enable mapping of complex traits given their greater levels of genetic diversity, extensive population substructure, and distinct linkage disequilibrium patterns. Methods: Here we perform a comprehensive genome-wide assessment of Parkinson's disease (PD) in 197,918 individuals (1,488 cases; 196,430 controls) of African and African admixed ancestry, characterizing population-specific risk, differential haplotype structure and admixture, coding and structural genetic variation and polygenic risk profiling. Findings: We identified a novel common risk factor for PD and age at onset at the GBA1 locus (risk, rs3115534-G; OR=1.58, 95% CI = 1.37 - 1.80, P=2.397E-14; age at onset, BETA =-2.004, SE =0.57, P = 0.0005), that was found to be rare in non-African/African admixed populations. Downstream short- and long-read whole genome sequencing analyses did not reveal any coding or structural variant underlying the GWAS signal. However, we identified that this signal mediates PD risk via expression quantitative trait locus (eQTL) mechanisms. While previously identified GBA1 associated disease risk variants are coding mutations, here we suggest a novel functional mechanism consistent with a trend in decreasing glucocerebrosidase activity levels. Given the high population frequency of the underlying signal and the phenotypic characteristics of the homozygous carriers, we hypothesize that this variant may not cause Gaucher disease. Additionally, the prevalence of Gaucher's disease in Africa is low. Interpretation: The present study identifies a novel African-ancestry genetic risk factor in GBA1 as a major mechanistic basis of PD in the African and African admixed populations. This striking result contrasts to previous work in Northern European populations, both in terms of mechanism and attributable risk. This finding highlights the importance of understanding population-specific genetic risk in complex diseases, a particularly crucial point as the field moves toward precision medicine in PD clinical trials and while recognizing the need for equitable inclusion of ancestrally diverse groups in such trials. Given the distinctive genetics of these underrepresented populations, their inclusion represents a valuable step towards insights into novel genetic determinants underlying PD etiology. This opens new avenues towards RNA-based and other therapeutic strategies aimed at reducing lifetime risk. Evidence Before this Study: Our current understanding of Parkinson's disease (PD) is disproportionately based on studying populations of European ancestry, leading to a significant gap in our knowledge about the genetics, clinical characteristics, and pathophysiology in underrepresented populations. This is particularly notable in individuals of African and African admixed ancestries. Over the last two decades, we have witnessed a revolution in the research area of complex genetic diseases. In the PD field, large-scale genome-wide association studies in the European, Asian, and Latin American populations have identified multiple risk loci associated with disease. These include 78 loci and 90 independent signals associated with PD risk in the European population, nine replicated loci and two novel population-specific signals in the Asian population, and a total of 11 novel loci recently nominated through multi-ancestry GWAS efforts.Nevertheless, the African and African admixed populations remain completely unexplored in the context of PD genetics. Added Value of this Study: To address the lack of diversity in our research field, this study aimed to conduct the first genome-wide assessment of PD genetics in the African and African admixed populations. Here, we identified a genetic risk factor linked to PD etiology, dissected African-specific differences in risk and age at onset, characterized known genetic risk factors, and highlighted the utility of the African and African admixed risk haplotype substructure for future fine-mapping efforts. We identified a novel disease mechanism via expression changes consistent with decreased GBA1 activity levels. Future large scale single cell expression studies should investigate the neuronal populations in which expression differences are most prominent. This novel mechanism may hold promise for future efficient RNA-based therapeutic strategies such as antisense oligonucleotides or short interfering RNAs aimed at preventing and decreasing disease risk. We envisage that these data generated under the umbrella of the Global Parkinson's Genetics Program (GP2) will shed light on the molecular mechanisms involved in the disease process and might pave the way for future clinical trials and therapeutic interventions. This work represents a valuable resource in an underserved population, supporting pioneering research within GP2 and beyond. Deciphering causal and genetic risk factors in all these ancestries will help determine whether interventions, potential targets for disease modifying treatment, and prevention strategies that are being studied in the European populations are relevant to the African and African admixed populations. Implications of all the Available Evidence: We nominate a novel signal impacting GBA1 as the major genetic risk factor for PD in the African and African admixed populations. The present study could inform future GBA1 clinical trials, improving patient stratification. In this regard, genetic testing can help to design trials likely to provide meaningful and actionable answers. It is our hope that these findings may ultimately have clinical utility for this underrepresented population.

MAPT allele and haplotype frequencies in Nigerian Africans: Population distribution and association with Parkinson's disease risk and age at onset.

INTRODUCTION: The association between MAPT and PD risk may be subject to ethnic variability even within populations of similar geographical origin. Data on MAPT haplotype frequencies, and its association with PD risk in black Africans are lacking. We aimed to determine the frequencies of MAPT haplotypes and their role as risk factors for PD and age at onset in Nigerians. METHODS: The haplotype and genotype frequencies of MAPT rs1052553 were analysed in 907 individuals with PD and 1022 age-matched healthy controls from the Nigeria Parkinson's Disease Research network cohort. Clinical data related to PD included age at study, age at onset (AAO), and disease duration. RESULTS: The frequency of the H1 haplotype was 98.7% in PD, and 99.1% in controls (p = 0.19). The H2 haplotype was present in - 1.3% of PD and 0.9% of controls (p = 0.24). The most frequent MAPT genotype was H1H1 (PD - 97.5%, controls - 98.2%). The H1 haplotype was not associated with PD risk after accounting for gender and AAO (Odds ratio for H1/H1 vs H1/H2 and H2/H2: 0.68 (95% CI:0.39-1.28); p = 0.23). CONCLUSIONS: Our findings support previous studies that report a low frequency of the MAPT H2 haplotype in black ancestry Africans but document its occurrence in Nigerians. The MAPT H1 haplotype was not associated with an increased risk or age at onset of PD in this cohort.

MAPT allele and haplotype frequencies in Nigerian Africans: population distribution and association with Parkinson's disease risk and age at onset.

Background: The microtubule-associated protein tau ( MAPT ) gene is critical because of its putative role in the causal pathway of neurodegenerative diseases including Parkinson's disease (PD). However, there is a lack of clarity regarding the link between the main H1 haplotype and risk of PD. Inconsistencies in reported association may be driven by genetic variability in the populations studied to date. Data on MAPT haplotype frequencies in the general population and association studies exploring the role of MAPT haplotypes in conferring PD risk in black Africans are lacking. Objectives: To determine the frequencies of MAPT haplotypes and explore the role of the H1 haplotype as a risk factor for PD risk and age at onset in Nigerian Africans. Methods: The haplotype and genotype frequencies of MAPT rs1052553 were analysed using PCR-based KASP™ in 907 individuals with PD and 1,022 age-matched neurologically normal controls from the Nigeria Parkinson's Disease Research (NPDR) network cohort. Clinical data related to PD included age at study, age at onset, and disease duration. Results: The frequency of the main MAPT H1 haplotype in this cohort was 98.7% in individuals with PD, and 99.1% in healthy controls (p=0.19). The H2 haplotype was present in 41/1929 (2.1%) of the cohort (PD - 1.3%; Controls - 0.9%; p=0.24). The most frequent MAPT genotype was H1H1 (PD - 97.5%, controls - 98.2%). The H1 haplotype was not associated with PD risk after accounting for gender and age at onset (Odds ratio for H1/H1 vs H1/H2 and H2/H2: 0.68 (95% CI:0.39-1.28); p=0.23). Conclusions: Our findings support previous studies that report a low frequency of the MAPT H2 haplotype in black ancestry Africans, but document its occurrence in the Nigerian population (2.1%). In this cohort of black Africans with PD, the MAPT H1 haplotype was not associated with an increased risk or age at onset of PD.

APOE E4 is associated with impaired self-declared cognition but not disease risk or age of onset in Nigerians with Parkinson's disease.

The relationship between APOE polymorphisms and Parkinson's disease (PD) in black Africans has not been previously investigated. We evaluated the association between APOE polymorphic variability and self-declared cognition in 1100 Nigerians with PD and 1097 age-matched healthy controls. Cognition in PD was assessed using the single item cognition question (item 1.1) of the MDS-UPDRS. APOE genotype and allele frequencies did not differ between PD and controls (p > 0.05). No allelic or genotypic association was observed between APOE and age at onset of PD. In PD, APOE ε4/ε4 conferred a two-fold risk of cognitive impairment compared to one or no ε4 (HR: 2.09 (95% CI: 1.13-3.89; p = 0.02)), while APOE ε2 was associated with modest protection against cognitive impairment (HR: 0.41 (95% CI 0.19-0.99, p = 0.02)). Of 773 PD with motor phenotype and APOE characterized, tremor-dominant (TD) phenotype predominated significantly in ε2 carriers (87/135, 64.4%) compared to 22.2% in persons with postural instability/gait difficulty (PIGD) (30/135) and 13.3% in indeterminate (ID) (18/135, 13.3%) (p = 0.037). Although the frequency of the TD phenotype was highest in homozygous ε2 carriers (85.7%), the distribution of motor phenotypes across the six genotypes did not differ significantly (p = 0.18). Altogether, our findings support previous studies in other ethnicities, implying a role for APOE ε4 and ε2 as risk and protective factors, respectively, for cognitive impairment in PD.

A Cross-Sectional Comprehensive Assessment of the Profile and Burden of Non-motor Symptoms in Relation to Motor Phenotype in the Nigeria Parkinson Disease Registry Cohort.

BACKGROUND: Data on non-motor symptoms (NMS) in black Africans with Parkinson's disease (PD) are sparse. OBJECTIVE: To describe the profile of NMS in the Nigeria PD Registry (NPDR) cohort and explore the relationship between NMS and PD motor phenotype. METHODS: We conducted a cross-sectional study of the frequency and burden of NMS, based on the non-motor symptoms scale (NMSS) and the Chaudhuri method respectively in our cohort. Baseline demographics, disease characteristics (Hoehn and Yahr stage, MDS-UPDRS total score and Part III motor score), motor phenotype (based on Stebbin et al's algorithm), and levodopa equivalent daily dose (LEDD) were documented. RESULTS: Data are presented for 825 PD whose mean age at study was 63.7 ± 10.1 years, female sex-221 [26.8%] while median PD duration was 36 months. PD phenotypes included tremor-dominant 466 (56.5%), postural instability and gait disorder (PIGD) 259 (31.4%), and indeterminate 100 (12.1%). 82.6% were on treatment (median LEDD of 500 mg/24 hours). 804 (97.5%) endorsed at least 1 NMS. The median NMSS score was 26.0 while subscores for urinary and sexual function domains were significantly higher in males (P < 0.05). PIGD-PD had more frequent NMS and higher frequency of severe/very severe NMSS burden (P = 0.000 for both). Nocturia and fatigue were the most prevalent NMS overall and across motor subtypes. PIGD phenotype and total UPDRS scores were the independent determinants of NMSS scores (P = 0.000). CONCLUSION: The profile and burden of NMS, and association with motor subtype in our black African cohort is largely similar to descriptions from other populations.

The Nigeria Parkinson Disease Registry: Process, Profile, and Prospects of a Collaborative Project.

BACKGROUND: Clinical disease registries are useful for quality improvement in care, benchmarking standards, and facilitating research. Collaborative networks established thence can enhance national and international studies by generating more robust samples and credible data and promote knowledge sharing and capacity building. This report describes the methodology, baseline data, and prospects of the Nigeria Parkinson Disease Registry. METHODS: This national registry was established in November 2016. Ethics approval was obtained for all sites. Basic anonymized data for consecutive cases fulfilling the United Kingdom Parkinson's Disease Brain Bank criteria (except the exclusion criterion of affected family members) are registered by participating neurologists via a secure registry website (www.parkinsonnigeria.com) using a minimal common data capture format. RESULTS: The registry had captured 578 participants from 5 of 6 geopolitical zones in Nigeria by July 2019 (72.5% men). Mean age at onset was 60.3 ± 10.7 years; median disease duration (interquartile range) was 36 months (18-60.5 months). Young-onset disease (<50 years) represented 15.2%. A family history was documented in 4.5% and 7.8% with age at onset <50 and ≥ 50, respectively. The most frequent initial symptom was tremor (45.3%). At inclusion, 93.4% were on treatment (54.5% on levodopa monotherapy). Per-capita direct cost for the registry was $3.37. CONCLUSIONS: This is the first published national Parkinson's disease registry in sub-Saharan Africa. The registry will serve as a platform for development of multipronged evidence-based policies and initiatives to improve quality of care of Parkinson's disease and research engagement in Nigeria. © 2020 International Parkinson and Movement Disorder Society.

Poststroke emotionalism with dacrystic (Crying) episodes - making a case for risperidone.

Emotionalism is the abnormal expression of emotions like crying and laughing and could follow stroke, traumatic brain injury, multiple sclerosis and amyotrophic lateral sclerosis. Emotionalism has been known to respond therapeutically to different classes of drugs including tricyclic antidepressants like imipramine, Selective Serotonin Reuptake Inhibitors (SSRI) like sertraline and citalopram, anticonvulsants like lamotrigine, dopamine precursors like levodopa and NMDA receptor antagonists like dextromethorphan. Classical antipsychotics are hardly prescribed for emotionalism alone without psychotic features. In this case report, an eighty year old woman with a dominant fronto-temporal infarctive stroke with right faciohemiparesis presented with frequent crying (dacrystic) episodes after a month of onset of stroke and who did not satisfy DSM IV criteria for depression nor had other psychotic features. Serial trial of SSRIs and dextromethorphan/quinidine could not help until risperidone, an antipsychotic was introduced with resolution of crying episodes. The response to risperidone after trial of SSRIs and dextromethorphan/quinidine which are considered the gold standard for post-stroke emotionalism (PSE), could be another therapeutic dimension in the management of emotionalism in general and PSE in particular.

Résumé L'émotivité est l'expression anormale d'émotions comme les pleurs et les rires et pourrait suivre un accident vasculaire cérébral, une lésion cérébrale traumatique, la sclérose en plaques et la sclérose latérale amyotrophique. L'émotionnisme a été connu pour répondre thérapeutiquement à différentes classes de médicaments incluant les antidépresseurs tricycliques comme l'imipramine, les inhibiteurs sélectifs du recaptage de la sérotonine (ISRS) comme la sertraline et le citalopram, les anticonvulsivants comme la lamotrigine, les précurseurs de la dopamine comme la lévodopa et les antagonistes des récepteurs NMDA comme le dextrométhorphane. Les antipsychotiques classiques ne sont guère prescrits pour l'émotivité seule sans caractéristiques psychotiques. Dans ce cas, une femme de quatre-vingts ans avec un infarctus fronto-temporal dominant avec faciohemiparesis droite a présenté des épisodes pleurs fréquents (dacrystiques) après un mois d'apparition de l'accident vasculaire cérébral et qui ne répondaient pas aux critères du DSM IV. fonctionnalités. Essai en série des ISRS et dextrométhorphane / quinidine n'a pas pu aider jusqu'à risperidone, un antipsychotique a été introduit avec la résolution des épisodes de pleurs. La réponse à la rispéridone après essai des ISRS et de la dextrométhorphane / quinidine, considérés comme l'étalon-or de l'émotivité post-AVC, pourrait constituer une autre dimension thérapeutique dans la gestion de l'émotivité en général et des EPS en particulier.

Burden of informal caregivers of stroke survivors: Validation of the Zarit burden interview in an African population.

BACKGROUND: Informal care giving can be burdensome particularly where the option of institutionalized informal care scarcely exist. OBJECTIVE: To look at the burden of informal caregivers of stroke survivors using the Zarit burden interview (ZBI). METHOD: 64 stroke survivors were assessed for demographics of age, gender, duration of follow-up since discharged from in-patient care, modified Rankin score at the time of discharge and at the time of evaluation for this study and the most important informal care giver at home was also assessed for whether care giving was telling on their health or life in any negative way. All the caregivers were subsequently assessed with the ZBI. RESULTS: Mean age of most important informal care givers was 40.67 ± 14.27 years and the sex distribution was 33(51.6%) female and 29(45.4%) males. 21(32.8%) reported that caregiving was a health burden. Mean ZBI scores were significantly higher (30.19 ± 14.81 vs 20.30 ± 12.96, P < 0.01) in those that reported that caregiving was telling on their health. ZBI overall rating of burden of caregiving was also significantly associated with whether caregiving was telling on the health of caregiver (P = 0.01) and also symmetrically agreed with whether the burden of caregiving was telling on health (k = 0.33, P< 0.01). The sensitivity and specificity of ZBI were 70% and 68.4% respectively on ROC statistics (AUC = 0.67, P = 0.017). CONCLUSION: Reported burden of informal caregiving of about 33% is in our opinion huge. The moderate sensitivity and specificity of the ZBI means it could be safely used in the population studied.

Cognitive function in patients with newly diagnosed HIV infection in a tertiary health facility in south - west Nigeria: Assessment using computer-assisted neuropsychological test battery.

INTRODUCTION: Cognitive dysfunction is common among patients with human immunodeficiency virus (HIV) infection however there are few reports from sub-Saharan Africa. METHODS: We studied fifty seropositive patients with human immunodeficiency virus (HIV) infection along with fifty matched seronegative control. Medical history taking and general physical and neurological examinations were done for all study participants. Laboratory evaluations and chest X-ray were done for all the patients. The cognitive function was done with the aid of 'Fepsy' automated test battery for all the study participants. The data was analyzed with statistical package for social sciences software version 21.0 (SPSS Chicago IL). RESULT: About 70% of the HIV patients were in advanced disease stage. The auditory and visual reaction times, binary choice reaction times, and computerized visual scanning task time were more prolonged in the HIV group (p < 0.05). There were also increased memory accuracy and binary choice task accuracy in the HIV group (p < 0.05). However the vigilance task performance was similar between the two groups (p > 0.05). Among the patients with HIV infection, the presence of anemia and central nervous system toxoplasmosis infection was associated with prolonged auditory and visual reaction times. CONCLUSION: There was a high rate of cognitive dysfunction in patients with HIV infection in this study.

Intellectual Impairment in Patients with Newly Diagnosed HIV Infection in Southwestern Nigeria.

Neurocognitive impairment is a detrimental complication of HIV infection. Here, we characterized the intellectual performance of patients with newly diagnosed HIV infection in southwestern Nigeria. We conducted a prospective study at Owo Federal Medical Center by using the adapted Wechsler Adult Intelligence Scale (WAIS). The raw scores were converted to standardized scores (z-scores) and correlated with clinical and laboratory findings. Fifty-eight HIV positive patients were recruited; 72% were in WHO stages 3 and 4. We detected a high rate of intellectual impairment in HIV positive patients and controls (63.8% and 10%, resp.; P < 0.001). HIV positive patients performed worse throughout the subtests of both verbal and performance intelligence quotients. Presence of opportunistic infections was associated with worse performance in the similarities and digit symbol tests and performance and full scale scores. Lower body weight correlated with poor performance in different WAIS subtests. The high rate of advanced disease stage warrants measures aimed at earlier diagnosis and treatment. Assessment of neurocognitive performance at diagnosis may offer the opportunity to improve functioning in daily life and counteract disease progression.

Benin stroke score in the diagnosis of acute brain infarct: a pilot study in Senegalese Africans.

BACKGROUND: The Benin stroke score (BSS) is a validated tool in the diagnosis of intracerebral hemorrhage (ICH) but not in the diagnosis of brain infarct. The aim of this report is to specifically validate the BSS in the clinical diagnosis of acute brain infarct. MATERIALS AND METHODS: A total of 60 participants with a presumptive diagnosis of acute stroke in a busy tertiary neurologic care centre in Francophone West Africa were evaluated within 48 h of onset of symptoms with the BSS after basic data were obtained, before computed tomography or magnetic resonance imaging scans was used as gold standard. BSS is a three-item tool that scores age, supine diastolic blood pressure, and Glasgow coma scale with a minimum score of 0 and a maximum score of 3.5. A score of 2.5 or less is diagnostic for a brain infarct. RESULTS: The sensitivity, specificity, positive predictive value, negative predictive value, positive and negative likelihood ratios of BSS in the diagnosis of brain infarct were 83.78%, 69.56%, 81.57%, 72.72%, 2.75, and 0.23, respectively. BSS agreed with neuroimaging in the diagnosis of all stroke subtypes significantly on kappa statistics (k = 0.538, P < 0.001) and interrater and intrarater reliability between two cadres of medical personnel in the use of BSS were significant (r = 0.9. 0.95, 0.95, P < 0.001, <0.001, <0.001), respectively. CONCLUSION: BSS as a simple clinical tool could be used with appreciable levels of accuracy in the clinical diagnosis of acute brain infarct where neuroimaging may not be available or immediately inaccessible, much the same way it is being used for ICH.

Early post-acute stroke seizures: clinical profile and outcome in a Nigerian stroke unit.

AIM: To describe the basic clinico-demographic profile and outcome of Early Post-Acute Stroke Seizures (EPASS). MATERIALS AND METHODS: Two-hundred and fifty one patients admitted within 24 h of onset of stroke symptoms into the stroke unit of a tertiary care hospital were followed up for convulsive seizure(s) within 7 days of admission and for disease outcome in 42 days. Stroke subtype was defined by cranial computed tomography and ictal phenomenon was as described by the stroke unit doctors. Stroke severity was by the Canadian Neurological Scale (CNS) and Glasgow Coma Scale (GCS). Seizures were characterized as partial, generalized, or status. Stroke outcome was defined as discharge from inpatient care to follow-up or still in care and all cause in-hospital death. Data was compared between the group with and without seizures. The effect of age, sex, blood sugar, GCS, CNS, and seizure type on stroke outcome and time to in-hospital death in EPASS was tested on logistic regression and Cox proportional hazard regression. RESULT: EPASS occurred in 9.96% of subjects and intracerebral infarct was more associated with EPASS, a finding different from what is dominant in western literature. CONCLUSION: Profile of EPASS may appear different in terms of stroke subtype in Sub-Saharan African populations. Larger prospective studies may clarify the position better.

Should non acute and recurrent headaches have neuroimaging before review by a Neurologist?--a review in a Southern Nigerian Tertiary Hospital.

BACKGROUND: Headache is a common complaint in general practice and it is known that most headaches are primary and that the yield of neuroimaging like cranial computed tomography (CT) in headache is generally low. In this study, we were able to demonstrate that the yield of neuroimaging in non-acute and recurrent headache could be higher if cases are reviewed first by a specialist Neurologist before cranial CT. METHOD: Seventy-four cases that were referred to the specialist neurology clinic with complaints of chronic and recurrent headaches without focal neurological deficit that had CT scan were reviewed consecutively using the short form of the International Classification of Headache Disorders second edition (ICHD 2) criteria after their demographics of age, sex were captured, to find out the proportion and characteristics of study cases that had identifiable cranial lesions on cranial CT scan. All cases were reviewed by a specialist Neurologist before CT scan and all CT films were reviewed by a specialist Radiologist. Age, sex and the distribution of CT findings were described from a frequency table and mean age of study cases with and without identifiable lesions on CT were compared with t-test for any significant difference and the effect of gender on the presence of identifiable lesions was tested with chi square and the agreement between clinical and CT diagnoses were tested on kappa statistics. RESULTS: (1) Mean age of cases was 37.55 (22.06) years. (2) No significant effect of gender was found on intracranial lesions (P = 0.345). (3) Intracranial lesions were found in 47.3% of cases and the mean age was higher compared to cases with normal findings on cranial CT (P = 0.019). (4) Clinical and CT diagnoses agreed in 56.2% of the cases (P = 0.000). CONCLUSION: The high yield of intracranial lesions may be accounted for by the method of selection of cases for cranial CT.