Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) and Human Immunodeficiency virus infection: dilemmas in diagnosis and management: a case series.

BACKGROUND: Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a recently described autoimmune inflammatory disorder of the central nervous system (CNS). There is limited data on the association between Human Immunodeficiency virus (HIV) infection and MOGAD. We report three patients with HIV infection and myelin oligodendrocyte glycoprotein (MOG) antibodies in the setting of other central nervous system infections. CASE DESCRIPTIONS: The first patient, a 44-year-old black African man, presented with acute disseminated encephalomyelitis (ADEM) with positive serum MOG antibodies. He made a significant recovery with corticosteroids but had a quick relapse and died from sepsis. The second patient, an 18-year-old black woman, presented with paraplegia and imaging revealed a longitudinally extensive transverse myelitis and had positive serum MOG antibodies. She remained paraplegic after methylprednisone and plasmapheresis treatments. Her rehabilitation was complicated by development of pulmonary embolism and tuberculosis. The third patient, a 43-year-old mixed-race woman, presented with bilateral painless visual loss. Her investigations were notable for positive MOG antibodies, positive Varicella Zoster Virus on cerebral spinal fluid (CSF) and hyperintense optic nerves on magnetic resonance imaging (MRI). Her vision did not improve with immunosuppression and eventually died from sepsis. CONCLUSION: Our cases illustrate the diagnostic and management challenges of MOGAD in the setting of advanced HIV infection, where the risk of CNS opportunistic infections is high even without the use of immunosuppression. The atypical clinical progression and the dilemmas in the diagnosis and treatment of these cases highlight gaps in the current knowledge of MOGAD among people with HIV that need further exploration.

Cognitive Impairment in Tuberculous Meningitis.

BACKGROUND: Cognitive impairment is reported as a common complication in adult tuberculous meningitis (TBM), yet few studies have systematically assessed the frequency and nature of impairment. Moreover, the impact of impairment on functioning and medication adherence has not been described. METHODS: A cognitive test battery (10 measures assessing 7 cognitive domains) was administered to 34 participants with human immunodeficiency virus (HIV)-associated TBM 6 months after diagnosis. Cognitive performance was compared with that a comparator group of 66 people with HIV without a history of tuberculosis. A secondary comparison was made between participants with TBM and 26 participants with HIV 6 months after diagnosis of tuberculosis outside the central nervous system (CNS). Impact on functioning was evaluated, including through assessment of medication adherence. RESULTS: Of 34 participants with TBM, 16 (47%) had low performance on cognitive testing. Cognition was impaired across all domains. Global cognitive performance was significantly lower in participants with TBM than in people with HIV (mean T score, 41 vs 48, respectively; P < .001). These participants also had lower global cognition scores than those with non-CNS tuberculosis (mean global T score, 41 vs 46; P = .02). Functional outcomes were not significantly correlated with cognitive performance in the subgroup of participants in whom this was assessed (n = 19). CONCLUSIONS: Low cognitive performance following HIV-associated TBM is common. This effect is independent of, and additional to, effects of HIV and non-CNS tuberculosis disease. Further studies are needed to understand longer-term outcomes, clarify the association with treatment adherence, a key predictor of outcome in TBM, and develop context-specific tools to identify individuals with cognitive difficulties in order to improve outcomes in TBM.

Adaptation and norming of the Edinburgh Cognitive and behavioural amyotrophic lateral sclerosis screen (ECAS) for three language groups in South Africa.

Objectives: To adapt and translate the Edinburgh Cognitive and behavioural amyotrophic lateral sclerosis screen (ECAS); to generate preliminary normative data for three language groups in South Africa (SA); to assess the convergent validity of the ECAS in SA samples. Methods: The ECAS was linguistically and culturally adapted for Afrikaans-, isiXhosa-, and English-speaking SA adults (n = 108, 100, and 53, respectively). Each language group was stratified by age and educational level. Cutoff scores for cognitive impairment were set at the group mean minus two standard deviations (SDs). A pilot sample of ALS patients and controls (n = 21 each) were administered the ECAS and an extensive neuropsychological evaluation (NPE) and the Montreal Cognitive Assessment (MoCA) to assess convergent validity. Results: Across the three language groups, the total ECAS cutoff scores ranged from 68 to 97. The ECAS score correlated significantly positively with educational level (p < 0.001) and negatively with age (p < 0.005). The restricted letter fluency task demonstrated a floor effect, particularly in Afrikaans-speakers. The mean total ECAS score (±SD) was similar in ALS patients (103.52 ± 11.90) and controls (100.67 ± 20.49; p = 0.58). Three (14.3%) ALS patients scored below the cutoff for cognitive impairment. Correlations between individual ECAS subtests and analogous NPE tests ranged from weak to moderate. The MoCA score was significantly positively correlated with the ECAS total score (r = 0.59; p = < 0.001). Conclusions: The adapted ECAS and associated normative data will aid cognitive screening of African ALS patients. Larger participant numbers are needed to assess the validity of the adapted instrument.

Pharmacogenetics of the Late-Onset Efavirenz Neurotoxicity Syndrome (LENS).

BACKGROUND: The late-onset efavirenz neurotoxicity syndrome (LENS) presents as ataxia and/or encephalopathy with supratherapeutic efavirenz plasma concentrations (>4 µg/mL). Efavirenz is primarily metabolized by cytochrome P450 2B6 (CYP2B6), with CYP2A6 as an accessory pathway. We hypothesized that participants with LENS would predominantly be CYP2B6 slow metabolizers. The aim of our study was to determine the frequency of CYP2B6 slow metabolizers in participants with LENS. METHODS: Adult HIV-positive participants on efavirenz-based antiretroviral therapy presenting with LENS were prospectively enrolled. Genetic polymorphisms known to be associated with increased efavirenz plasma concentrations in CYP2B6 (rs3745274, rs28399499, rs4803419) and CYP2A6 (rs28399433) were selected and used to determine proportions of slow metabolizers. Pharmacokinetic analyses were performed using liquid chromatography-tandem mass spectrometry. Median (IQR) plasma efavirenz and 8-hydroxyefavirenz were described. RESULTS: Fifteen participants were enrolled. Thirteen (13/15) were Black-African and 13 were female. Median weight was 49.9kg with a median duration on efavirenz of 2.2 years. All 15 participants were successfully genotyped as slow CYP2B6 metabolizers, with 6 participants additionally having CYP2A6 heterozygous genotype. Thirteen were receiving the CYP2A6 enzyme inhibitor isoniazid, and all 15 were genotypic NAT2 slow or intermediate acetylators. Efavirenz plasma concentration was markedly increased at 50.5 (47.0-65.4) µg/mL; 8-hydroxyefavirenz concentration was markedly decreased at 0.10 (0.07-0.15) µg/mL. CONCLUSIONS: Our cohort provides definitive evidence that LENS is associated with the CYP2B6 slow metabolizer genotype, with a median efavirenz plasma concentration >12-fold higher than the defined upper limit of the therapeutic range. Isoniazid and low body weight are important contributors to LENS development.

A novel locus for episodic ataxia:UBR4 the likely candidate.

Episodic ataxias (EAs) are rare neurological channelopathies that are characterized by spells of imbalance and a lack of co-ordination. There are seven clinically recognized EAs and multiple isolated cases. Five disease-causing genes have been identified to date. We describe a novel form of autosomal dominant EA in a large three-generation Irish family. This form of EA presents in early childhood with periods of unsteadiness generalized weakness and slurred speech during an attack, which may be triggered by physical tiredness or stress. Linkage analysis undertaken in 13 related individuals identified a single disease locus (1p36.13-p34.3) with a LOD score of 3.29. Exome sequencing was performed. Following data analysis, which included presence/absence within the linkage peak, two candidate variants were identified. These are located in the HSPG2 and UBR4 genes. UBR4 is an ubiquitin ligase protein that is known to interact with calmodulin, a Ca(2+) protein, in the cytoplasm. It also co-localizes with ITPR1 a calcium release channel that is a major determinant of mammal co-ordination. Although UBR4 is not an ion channel gene, the potential for disrupted Ca(2+) control within neuronal cells highlights its potential for a role in this form of EA.

Molecular characterisation of virus in the brains of patients with measles inclusion body encephalitis (MIBE).

BACKGROUND: During 2009/10 a major measles epidemic caused by genotype B3 occurred in South Africa. Measles inclusion body encephalitis (MIBE) was diagnosed in a number of highly immuno-compromised HIV patients. The diagnosis was based on typical clinical and MRI findings and positive measles virus PCR in brain or CSF.To characterize the brain virus, nucleoprotein, matrix, fusion and haemagglutinin genes from 4 cases was compared with virus from acutely infected patients. METHODS: cDNA was synthesized using random primers and viral genes were amplified by nested RT-PCR. PCR products were sequenced in the forward and reverse direction and a contig of each gene was created. Sequences were aligned with reference sequences from GenBank and other local sequences. RESULTS: Brain virus was very similar to the South African epidemic virus. Features characteristic of persistent measles virus in the brain were absent. Mutation frequency in brain virus was similar to epidemic virus and had the same substitution preference (U to C and C to U). The virus of 2 patients had the same L454W mutation in the fusion protein. CONCLUSION: The brain virus was very similar to the epidemic strain. The relatively few mutations probably reflect the short time from infection to brain disease in these highly immuno-compromised patients.

Compliance with McDonald criteria and red flag recognition in a general neurology practice in Ireland.

BACKGROUND: The revised McDonald criteria aim to simplify and speed the diagnosis of multiple sclerosis (MS). An important principle of the criteria holds there should be no better explanation for the clinical presentation. In Miller et al.'s consensus statement on the differential diagnosis of MS, red flags are identified that may suggest a non-MS diagnosis. OBJECTIVE: All new patients with a practice diagnosis of MS were assessed for compliance with McDonald criteria. The group of patients not fulfilling criteria was followed up to assess compliance over time. At the end of the follow-up period, red flags were sought in the group of patients who remained McDonald criteria negative. METHODS: Clinical notes and paraclinical tests were examined retrospectively for compliance with McDonald criteria and for the presence of red flags. RESULTS: Sixty-two patients were identified, with two lost to follow-up. Twenty-six (42%) patients fulfilled criteria at diagnosis. After 53 months follow-up, 47 (78%) patients fulfilled criteria. In the 13 (22%) patients who remain McDonald criteria negative, a total of 20 red flags were identified, ranging from one to six per patient. Alternative diagnoses were considered and further investigations performed in 10 patients with no significantly abnormal results. CONCLUSION: Twenty-two percent of patients still do not fulfill McDonald criteria after 53 months. Dissemination in time was not proven in the majority of patients and the lack of follow-up neuroimaging was an important factor in this. Red flags may be useful in identifying alternative diagnoses, but the yield was low in our cohort.