Browsing by Subject "Neurology"
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- ItemOpen AccessExploring social cognition in patients with apathy following acquired brain damage(2014-01-23) Njomboro, Progress; Humphreys, Glyn W; Deb, ShoumitroAbstract Background Research on cognition in apathy has largely focused on executive functions. To the best of our knowledge, no studies have investigated the relationship between apathy symptoms and processes involved in social cognition. Apathy symptoms include attenuated emotional behaviour, low social engagement and social withdrawal, all of which may be linked to underlying socio-cognitive deficits. Methods We compared patients with brain damage who also had apathy symptoms against similar patients with brain damage but without apathy symptoms. Both patient groups were also compared against normal controls on key socio-cognitive measures involving moral reasoning, social awareness related to making judgements between normative and non-normative behaviour, Theory of Mind processing, and the perception of facial expressions of emotion. We also controlled for the likely effects of executive deficits and depressive symptoms on these comparisons. Results Our results indicated that patients with apathy were distinctively impaired in making moral reasoning decisions and in judging the social appropriateness of behaviour. Deficits in Theory of Mind and perception of facial expressions of emotion did not distinguish patients with apathy from those without apathy. Conclusion Our findings point to a possible socio-cognitive profile for apathy symptoms and provide initial insights into how socio-cognitive deficits in patients with apathy may affect social functioning.
- ItemOpen AccessMotor neuron disease in an African population: A review of current literature and a case series of the flail arm variant in the Western Cape(2018) Cross, Helen; Heckmann, Jeannine MBackground: Motor neuron disease (MND) is a devastating neurodegenerative disorder, with recognised phenotypic subtypes. Although prevalent in all parts of the world, little is described in the literature with regards motor neuron disease as it occurs in African populations. Aims: This study had two main aims: to conduct a systematic review of the current available literature on motor neuron disease in persons of African genetic descent, and to describe the clinical phenotype in a subgroup of MND patients with the flail arm (FA) variant seen at Groote Schuur Hospital MND clinic. Methods: In order to identify the current published knowledge of motor neuron disease in African populations, a systematic literature review was conducted using Pubmed and Google Scholar. For the case series description, patients presenting to the Groote Schuur Hospital MND clinic with a phenotype of restricted proximal upper limb, lower motor neuron involvement for at least 12 months after symptom onset, during the time period of March 2014 to September 2016, were considered for inclusion. A full clinical description of each case, including history, examination and electrophysiological findings, was conducted. Results: Review of the available literature on MND as it occurs in persons with African ancestry revealed that little is well described. Although there are a few original studies, all are small and most are out-dated. Some trends emerged, including younger age at onset of disease, tendency to longer survival, and possibly more frequent presentation with bilateral upper limb involvement. Six cases of FA variant of MND, representing 13% of the MND clinic cohort seen over the 2.5 years given time period, all with African genetic ancestry by self-categorization, are reported illustrating the various previously described features of this phenotype. Even within these few cases, there is variation in presentation and disease course. Conclusions: More research is required on African populations to address the questions surrounding MND as it occurs in Africans, including phenotypic and genetic similarities or differences to other populations. Although controversy surrounding exact case definition of the FA variant of MND remains, it does represent a unique phenotype, and seems to occur in patients of African genetic ancestry in a similar manner to that described in Caucasian populations.
- ItemOpen AccessMyasthenia Gravis mimics: An audit of cases identified at Groote Schuur Hospital over 20 years(2019) Neshuku, Saara Ndinelago; Heckmann, Jeanine MBackground: Myasthenia gravis (MG) is characterised by fatigable muscle weakness. The diagnosis is made clinically and supported by ancillary tests such as electrophysiological studies, autoantibodies and pharmacological responses. Autoimmune MG will respond to immune therapy. Although there are several case reports of patients who were incorrectly diagnosed as MG, this study describes the MG mimics encountered at Groote Schuur Hospital, Cape Town, over a period of 20 years. Aims & Methods: To describe the MG mimics captured in the MG database (1996 to 2017) by final diagnosis, the age at symptom onset, the time delay and clues which led to the final diagnosis. Results: There were 31 cases identified; 10 were probable congenital myasthenic syndromes (CMS), 6 functional neurological symptoms (FNS), 6 motor neuron disease (MND) variants, 3 mitochondrial cytopathies, 4 had definite or probable muscular dystrophy (MD), 1 progressive supranuclear palsy and 1 with a multiple sclerosis brainstem relapse. Median age at symptom onset was 10 years for CMS, 18 for mitochondrial cytopathies, 53 for FNS, 58 for the muscular dystrophy cases and 63 years for those with MND. The median time delay between the false “MG” diagnoses to the reviewed diagnosis, which also corresponds to the time on immunotherapies, was 45 months in CMS, 48 months in mitochondrial cytopathy, 4 in MND, and less than 3 months in FNS, MD, PSP and MS. The most important factor for reviewing the diagnosis was treatment unresponsiveness to immune therapy. Some of the CMS and mitochondrial cytopathy cases were treated with immune therapies for many years, without responsiveness, before referral to our centre. Additional features for CMS were childhood onset, family history of similar symptoms and, although no response to immune therapies, they responded to pyridostigmine +/- salbutamol. Mitochondrial cytopathies had long duration of symptoms and the diagnosis was confirmed by mitochondrial DNA deletion detection. MND patients showed disease progression within a few weeks despite some transient improvement with anticholinesterases. The FNS diagnoses were based on signs which were inconsistent and symptoms resolved after psychotherapy. Two MD cases (myotonic muscular dystrophy and probable oculopharyngeal muscular dystrophy, respectively) presented with respiratory failure, and could not be weaned off invasive ventilation. Conclusion: The main points are that, not all patients with ptosis and fatigable symptoms have myasthenia gravis. Non-responsiveness to immune therapies should raise suspicion of an alternative diagnosis and prompt referral to a specialist clinic. Transient modest improvement in bulbar and limb muscle symptoms have been observed in patients with early manifestations of motor neuron disease.
- ItemOpen AccessA review of cases of motor neurone disease seen at Groote Schuur Hospital from 2005 to 2010(2014) Daude, Amina; Combrinck, MarcMotor neurone disease (MND) is a rare progressive neurodegenerative disorder in which selective degeneration of the motor neurones of the brain and spinal cord occurs. Progressive weakness of limb, bulbar and respiratory muscles eventually results in death. Most descriptive and epidemiological studies of MND have been performed in the industrialized countries of Europe and North America. We know very little about the incidence or prevalence of MND in Africa in general and South Africa in particular. However, anecdotal evidence based on observations by clinicians in the neurology and geriatric medical clinics at Groote Schuur Hospital suggest that the condition is not uncommonly seen, even in younger patients. Furthermore, many cases appear to originate from the West Coast area of the Western Cape. The proposed study aimed at describing the demographic and clinical characteristics of MND seen at Groote Schuur Hospital between 2005 and 2010. I hypothesized that disease duration, measured from age of onset of first symptoms to death, would be shorter in patients with bulbar-onset disease, in younger-onset disease, and in patients with higher CSF protein and blood creatine kinase levels at baseline. Furthermore, age of onset of the disease would be younger in familial compared with sporadic MND. I also hypothesized that smoking and certain occupational exposures might be risk factors for MND, that there would be a male preponderance of the disease, and that a disproportionate number of cases would come from the West Coast region. This was a retrospective study. I reviewed the clinical notes of cases of motor neurone disease and collected data relevant to the aims and hypotheses described above. I applied the El Escorial diagnostic criteria for MND to check the validity of the diagnoses. Mortality data were obtained through the Burden of Diseases Research Unit at the South African Medical Research Council. Forty eight patients were identified who met El Escorial criteria for the diagnosis of probable or definite MND. The median age of onset of the disease was 54 (IQR 47-63) and the mean duration of the disease from earliest symptoms to death was 2 years (IQR 1-3). These did not differ significantly between bulbar and limb-onset disease sub-types. There was a male preponderance of the disease (60%) and the majority of patients (60%) were smokers. African patients tended to have a younger age of onset. Occupations involving potential exposure to chemicals were disproportionately represented in the MND patients compared with the general population of the Western Cape. People from the West Coast region were not disproportionately represented in the patient population. Baseline CSF protein and serum creatine kinase levels were not associated with disease duration. The characteristics of MND cases seen at Groote Schuur Hospital between 2005 and 2010 are similar to those described in the world literature. Smoking and chemical exposure may be risk factors for the disease. There was no evidence of clustering of cases. This study will serve as the basis for future larger prospective studies on MND prevalence and aetiology in South Africa.
- ItemOpen AccessThe spectrum of acute and subacute myelopathy(1984) Silber, Michael HAcute and subacute diseases causing intrinsic spinal cord damage are confusing and poorly defined clinically and pathologically. of this study is: The purpose 1. To analyse the spectrum of conditions responsible for acute and subacute myelopathy in South Africa. 2. To categorise the clinical presentations and prognosis of the illnesses and to correlate these with aetiology. 3. To assess the validity of diagnostic criteria for acute and subacute myelopathy in general and for the different aetiological groups. 4. To review the literature and to correlate previous studies with the present one. Thirty-four patients fulfilling strict criteria nave been identified over a seven-and-a-half-year period using the Groote Schuur Hospital computer retrieval system. Although the study was essentially retrospective, 11 of these patients were seen personally during their acute illnesses. All these patients have suffered from illnesses causing spinal cord dysfunction in the absence of trauma, physical agents or any extrinsic pressure such as might be caused by tumours or spondylosis. Maximum disability was reached in less than 8 weeks. In 17 patients no cause was identified. The clinical features, laboratory findings and courses have been analysed. Among the results, a high percentage of patients with Brown-Sequard Syndromes were found with possible significance for the pathogenesis of the illness. Seven patients with meningovascular syphilis were analysed as well as 2 additional patients with spinal cord syphilis not fulfilling the strict criteria of the study. Although well known before the penicillin era, this entity is not well described in modern neurological literature. Four patients had myelopathy associated with pulmonary tuberculosis in the absence of tuberculous meningitis or spinal disease. Three of these 4 patients also developed optic neuropathy. The association of these conditions has previously been described in only a very few patients. Two patients had Epstein-Barr virus infections and 1 had an infection with Mycoplasma pneumoniae. Two had systemic lupus erythematosus and 1 had an acute cord infarct following an aortic aneurysm repair. The literature is reviewed and the findings of this study correlated with previous ones. Conclusions regarding terminology, criteria for diagnosis, investigations, course and prognosis are discussed.
- ItemOpen AccessThe efficacy of an online learning tool in improving EEG analysis and interpretation skills of Technologists, Neurology Registrars and Neurologists(2021) Asukile, Melody Tunsubilege; Tucker, Lawrence; Viljoen, CharleBackground Scalp electroencephalography (EEG) remains an invaluable neurophysiological tool in supporting the diagnosis and management of epilepsy and encephalopathy, however, most sub-Saharan countries have very few neurologists per population for EEG analysis and training. Web-based, distance learning programs may provide effective electroencephalogram (EEG) training in resource-poor settings. EEGonline is an interactive, web-based, 6-month multi-modality, learning program designed to teach basic principles and clinical application of EEG. This study aimed to determine the effectiveness of EEGonline in improving EEG analysis and interpretation skills for neurologists, neurology residents and technologists, particularly in resource-limited settings. Methods Between June 2017 and November 2018, 179 learners were registered on the EEGonline course. Of these, 128 learners originating from 20 African countries, Europe, the UK and USA participated in the study. Pre- and post-course multiplechoice question (MCQ) test results and EEGonline user logs were analyzed. Differences in pre- and post-test performance were correlated with quantified exposure to various EEGonline learning modalities. Participants' impressions of EEGonline efficacy and usefulness were assessed through pre- and post-course perception surveys. Results Ninety-one participants attempted both pre- and post-course tests. Mean scores improved from 46.7% ± 17.6% to 64.1% ± 18% respectively (p< 0.001, Cohen's d 0.974). Almost all participants improved regardless of the amount of course material used, however those who used more, tended to have higher scores. The largest percentage-improvement was in the correct identification of normal features (43.2% to 59.1%, p< 0.001, Cohen's d 0.664) and artefacts (43.3% to 61.6%, p< 0.001, Cohen's d 0.836). Improvement in competence was associated with improvement in subjective confidence in EEG analysis. Overall confidence among 72 survey respondents improved significantly from 25.3% to 64.8% (p< 0.001). Lecture notes, end-of-module self-assessment quizzes and discussion forums were the most utilised learning modalities. The majority of survey respondents (97.2%) concluded that EEGonline was a useful learning tool and 93% recommended that similar courses should be included in EEG training curricula. Discussion Almost all participants showed significant improvement in EEG analysis competence (MCQ test scores) and confidence (survey responses) following the educational intervention, regardless of the amount of course material used. Improved identification of normal features and artefacts is particularly useful as it reduces the risk of misdiagnosis which can cause harm. The EEGonline course employed several learning techniques, through its multi-modality format, that may have contributed to the improvement observed, including, self-directed learning, cognitivism, collaborative learning, contextual learning and reflective learning. Subjective confidence likely correlates with competence and may be useful to gauge learners' needs and levels of understanding about a subject. Learning preferences vary among adult learners, it is unclear if one learning modality (that is, video, audio, lecture notes, epoch activities, discussion forums) is superior to others, but it seems as though a multi-modal approach may be the most sensible. Conclusions This study demonstrated that a multi-modal, online EEG teaching tool was effective in improving EEG analysis and interpretation skills and may be a useful supplement for EEG teaching especially in resource-poor settings. Given the optimistic findings of this study, we encourage the development and evaluation of further online neurology teaching tools.
- ItemOpen AccessThe role of the HIV-1 Tat protein in acute stroke: more than just a transactivator of transcription?(2018) McMullen, Kate Elizabeth; Bateman, Kathleen J; Combrinck, Marc; Bryer, AlanBackground: Individuals infected with the human immunodeficiency virus (HIV) are at increased risk of developing ischaemic stroke. The reasons for this are multifactorial, but HIV-associated vasculopathy is a potentially important cause. HIVinduced chronic inflammation may initiate endothelial dysfunction or accelerate vascular injury from other disease processes. Viral proteins such as the transactivator of transcription (Tat) are emerging role-players in HIV disease pathogenesis and have a putative role in HIV-associated endothelial dysfunction. Tat has paracrine proinflammatory effects, but its role in HIV-related stroke has not yet been investigated. Aims: The primary aim of this study was to determine whether specific Tat amino acid variants are associated with ischaemic stroke and biomarkers of inflammation and endothelial dysfunction in a group of HIV-1 subtype-C-infected individuals. In order to do so, I first determined the aetiology of stroke in these participants using clinical, biochemical and neuro-imaging data. A secondary aim of the study was to identify any HIV-related and/or other traditional stroke-related risk factors that might independently or cumulatively increase stroke risk. For comparison, these putative risk factors were also determined in a group of age-matched HIV-infected non-stroke controls. Finally, I aimed to identify any HIV-related factors and/or Tat amino acid variants that might distinguish strokes due to HIV-associated vasculopathy from other mechanisms of stroke. Methods: A case-control study was performed on 58 Subtype-C HIV-infected individuals with acute ischaemic stroke and 71 HIV-1 Subtype-C-infected non-stroke controls. Clinical, demographic, laboratory and imaging data were used to determined baseline differences between groups and to distinguish different stroke aetiologies. Exon 1 of the HIV-1 Tat protein was sequenced from peripheral blood samples of stroke participants and controls and amino acid variants were identified using viral epidemiology signature pattern analysis. Regression analyses were used to examine the correlation between residues at signature positions with biomarkers of inflammation and endothelial activation. Results: Stroke and control groups were mostly young (mean age 33 years) females (62.1% & 71.8%), and of Black African ancestry. The strokes showed a higher prevalence of some traditional cardiovascular risk factors. Individuals with strokes had a higher prevalence of antiretroviral treatment interruption (25.9% vs 0.0%, p= 0.003), lower CD4 nadir (112 vs 177.5 cells/μl, p=0.008) and CD4 count (208.5 vs 322.5 cells/μl, p=0.012) than controls. Median viral loads were elevated in both strokes and controls (4.58 & 4.13 log10 copies/ml, p=0.28). The most common causes of stroke were HIV-associated vasculopathy (43.1%) and opportunistic infections (22.4%). Two amino acid variants (proline at position 21 and histidine at position 29) were associated with acute ischaemic stroke. These positions were also associated with modulation of plasma interleukin 6 and monocyte chemoattractant protein 1 levels. Threonine at position 58 distinguished strokes due to alternative mechanisms from strokes due to HIV-associated vasculopathy. Conclusions: Two Tat protein amino acid variants are associated with stroke in HIV. The precise mechanisms by which these associations occur are not known. However, they are likely to be part of a multiple-hit phenomenon in HIV stroke pathogenesis. Tatmediated inflammation with endothelial dysfunction, HIV disease severity, treatment interruption and conventional cardiovascular risk factors probably all contribute to stroke aetiology. Thus, a multi-modal approach is needed to reduce ischaemic stroke risk in HIV infection.
- ItemOpen AccessThe utility of CSF PCR in central nervous system Varicella zoster infection in HIV(2015) Stanley, Alan Michael; Bryer, Alan; Bateman, KathleenAims: To assess the clinical and cerebrospinal fluid characteristics, and the role of tuberculous meningitis (TBM) as a confounder, in a cohort of HIV positive individuals with positive varicella zoster virus (VZV) positive cerebrospinal fluid PCR. Methods: Patients in the NHLS database at Groote Schuur Hospital with positive CSF VZV PCR who were also HIV co-infected and whose folders were available for clinical review were reviewed. Clinical and biochemical data were collected. Patients were divided into two groups based an accepted case definition for TBM. Differences between groups were assessed using Mann-Whitney U or Chi squared tests as appropriate. Results: There were 437 for VZV PCR over three years. Of these 98 were positive and, after exclusions, 31 HIV positive patients were included for further analysis. Median age was 31 and median CD4 count was 146 cells/mm³. 11 (35%) had meningitis and 8 (25%) had encephalitis. 13 (42%) met the case definition for TBM. Patients with CNS varicella were frequently confused whereas those with TBM presented sub-acutely. There were no differences in CSF characteristics. Additional organisms were detected 6 (19%) patients. 4 (13%) patients died in hospital. CSF TB culture was requested in 24 (77%) patients and extra CNS samples were sent in only 4 patients. Conclusion: The clinical and CSF presentation of CNS Varicella and TBM overlap and in this cohort patients were under investigated for TB. In settings of high TB prevalence the possibility of false positive PCR or incidental varicella reactivation should be considered.
- ItemOpen AccessUtility of EEG in the diagnosis of Efavirenz neurotoxity in HIV positive patients at a South African tertiary hospital(2023) Ssemmanda, Salvatore; Leepan, Edward; Tucker LawrenceBackground: Efavirenz (EFV) is a widely used antiretroviral medication in HIV treatment, primarily metabolized by cytochrome P450 CYP2B6, an enzyme whose loss of function polymorphisms have been associated with risk of EFV neurotoxicity. Patients with late onset efavirenz neurotoxicity syndrome (LENS) may present with encephalopathy, for which scalp EEG (sEEG) is indicated. Although a characteristic pattern of sEEGs waveforms in this deleterious condition has been suggested before, this has not been studied. Objective: The aim of this study was to investigate the utility of sEEG as a biomarker of LENS. Methods: We analysed a 5-year retrospective period of sEEGs performed at Groote Schuur Hospital (GSH) neuro-electrophysiology laboratory between June 1, 2016, and May 31, 2021. From these we selected 5319 sEEGs with a “Dysrhythmia grade II generalized” (Mayo Clinic, Lemieux et al) classification performed on patients whose referral indication for sEEG was either encephalopathy, efavirenz neurotoxicity, encephalitis, delirium, confusion, neurocognitive decline or subclinical seizures. Following several exclusions, the analysed cohort of 63 sEEGs comprised of 13 sEEGs from adult HIV positive patients with laboratory confirmed EFV neurotoxicity (plasma EFV levels of > 4 ug/mL) and 50 sEEGs as controls. These were presented to two qualified and experienced blinded sEEG interpreters instructed to record if a sEEG was typical for waveform features of EFV neurotoxicity or not, following a demonstration using representative sEEG samples from outside the study duration. All data were anonymized and secured on password protected computers for standard statistical analyses including measurement of inter rater agreement, reliability, and correlation. A p-value of less than 0.05 was considered for statistical significance. Results: Patients with EFV neurotoxicity had characteristic sEEG findings of diffuse, monomorphic, bisynchronous, high voltage, rhythmic 4 – 7 Hz theta frequency waveform runs. These were detectable by the blinded interpreters with significantly strong inter rater agreement (mean kappa statistic = 0.88, p < 0.001), strong positive correlation (Spearman correlation coefficient = 0.81, p < 0.001) and significantly strong inter rater reliability (intraclass correlation coefficient = 0.86, 95% CI 0.77 – 0.92, p < 0.001). Conclusion: Our observation adds knowledge to existing literature on EFV neurotoxicity, by describing a characteristic sEEG pattern in patients with LENS that is reliably detectable by qualified sEEG interpreters. This is in view of our observation that in a tertiary hospital with people referred with a clinical diagnosis of encephalopathy and other confusional states meeting clinical referral criteria described in this study, with a proven Dysrhythmia grade II generalized pattern on sEEG, certain sEEG criteria may distinguish HIV positive patients with LENS from other patients with the same grade of dysrhythmia on sEEG. This may support the timeous diagnosis of EFV neurotoxicity and facilitate the workup of encephalopathic patientson EFV. Our finding may be representative of an effect of EFV on the oscillatory and spike rhythms of the reticular thalamic nuclei. Further research using a larger number of patients, studying correlation between plasma EFV levels in patients with LENS and their sEEG characteristics is suggested as it may be an electrophysiological biomarker of disease severity.