An intronic GAA repeat expansion in FGF14 causes the autosomal-dominant adult-onset ataxia SCA50/ATX-FGF14.

Adult-onset cerebellar ataxias are a group of neurodegenerative conditions that challenge both genetic discovery and molecular diagnosis. In this study, we identified an intronic (GAA) repeat expansion in fibroblast growth factor 14 (FGF14). Genetic analysis of 95 Australian individuals with adult-onset ataxia identified four (4.2%) with (GAA)>300 and a further nine individuals with (GAA)>250. PCR and long-read sequence analysis revealed these were pure (GAA) repeats. In comparison, no control subjects had (GAA)>300 and only 2/311 control individuals (0.6%) had a pure (GAA)>250. In a German validation cohort, 9/104 (8.7%) of affected individuals had (GAA)>335 and a further six had (GAA)>250, whereas 10/190 (5.3%) control subjects had (GAA)>250 but none were (GAA)>335. The combined data suggest (GAA)>335 are disease causing and fully penetrant (p = 6.0 × 10-8, OR = 72 [95% CI = 4.3-1,227]), while (GAA)>250 is likely pathogenic with reduced penetrance. Affected individuals had an adult-onset, slowly progressive cerebellar ataxia with variable features including vestibular impairment, hyper-reflexia, and autonomic dysfunction. A negative correlation between age at onset and repeat length was observed (R2 = 0.44, p = 0.00045, slope = -0.12) and identification of a shared haplotype in a minority of individuals suggests that the expansion can be inherited or generated de novo during meiotic division. This study demonstrates the power of genome sequencing and advanced bioinformatic tools to identify novel repeat expansions via model-free, genome-wide analysis and identifies SCA50/ATX-FGF14 as a frequent cause of adult-onset ataxia.

Management of Poststroke Hyperglycemia: Results of the TEXAIS Randomized Clinical Trial.

BACKGROUND: Hyperglycemia in acute ischemic stroke reduces the efficacy of stroke thrombolysis and thrombectomy, with worse clinical outcomes. Insulin-based therapies are difficult to implement and may cause hypoglycemia. We investigated whether exenatide, a GLP-1 (glucagon-like peptide-1) receptor agonist, would improve stroke outcomes, and control poststroke hyperglycemia with minimal hypoglycemia. METHODS: The TEXAIS trial (Treatment With Exenatide in Acute Ischemic Stroke) was an international, multicenter, phase 2 prospective randomized clinical trial (PROBE [Prospective Randomized Open Blinded End-Point] design) enrolling adult patients with acute ischemic stroke ≤9 hours of stroke onset to receive exenatide (5 µg BID subcutaneous injection) or standard care for 5 days, or until hospital discharge (whichever sooner). The primary outcome (intention to treat) was the proportion of patients with ≥8-point improvement in National Institutes of Health Stroke Scale score (or National Institutes of Health Stroke Scale scores 0-1) at 7 days poststroke. Safety outcomes included death, episodes of hyperglycemia, hypoglycemia, and adverse event. RESULTS: From April 2016 to June 2021, 350 patients were randomized (exenatide, n=177, standard care, n=173). Median age, 71 years (interquartile range, 62-79), median National Institutes of Health Stroke Scale score, 4 (interquartile range, 2-8). Planned recruitment (n=528) was stopped early due to COVID-19 disruptions and funding constraints. The primary outcome was achieved in 97 of 171 (56.7%) in the standard care group versus 104 of 170 (61.2%) in the exenatide group (adjusted odds ratio, 1.22 [95% CI, 0.79-1.88]; P=0.38). No differences in secondary outcomes were observed. The per-patient mean daily frequency of hyperglycemia was significantly less in the exenatide group across all quartiles. No episodes of hypoglycemia were recorded over the treatment period. Adverse events of mild nausea and vomiting occurred in 6 (3.5%) exenatide patients versus 0 (0%) standard care with no withdrawal. CONCLUSIONS: Treatment with exenatide did not reduce neurological impairment at 7 days in patients with acute ischemic stroke. Exenatide did significantly reduce the frequency of hyperglycemic events, without hypoglycemia, and was safe to use. Larger acute stroke trials using GLP-1 agonists such as exenatide should be considered. REGISTRATION: URL: www.australianclinicaltrials.gov.au; Unique identifier: ACTRN12617000409370. URL: https://www.clinicaltrials.gov; Unique identifier: NCT03287076.

Prevalence of chronic inflammatory demyelinating polyneuropathy and multifocal motor neuropathy in two regions of Australia.

INTRODUCTION/AIMS: Immune-mediated neuropathies such as chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN) produce significant disability and often require maintenance treatment. There is a paucity of epidemiological data on these conditions in Australia. METHODS: We undertook a prevalence study of CIDP and MMN in North Queensland and Tasmania, coinciding with a national census. Diagnoses were classified against the diagnostic criteria of the European Federation of Neurological Societies/Peripheral Nerve Society. Case ascertainment was undertaken via multiple methods, including survey of local neurologists across public and private clinics, search of neurophysiology, neurology and hospital databases, search of admitted hospital database collections using ICD codes and through immunoglobulin therapy prescription lists. RESULTS: The crude prevalence of CIDP was 5.00 per 100,000 (95% confidence interval [CI] 3.79-6.62) and the crude prevalence of MMN was 1.33 per 100,000 (95% CI 0.78-2.27). Prevalence was also investigated using National Blood Authority numbers of cases prescribed immunoglobulin therapy, indicating a CIDP prevalence of 5.72 per 100,000 (95% CI 4.41-7.43) and MMN prevalence of 1.94 per 100,000 (95% CI 1.24-3.03). There was no significant difference between these numbers and those calculated through access of patient records locally. There was no significant difference in prevalence between Tasmania and North Queensland for any category. DISCUSSION: This study updates the prevalence of CIDP and MMN in Australia. Understanding the distribution of CIDP and MMN patients and their need for treatment is essential for future resource planning and to enable monitoring and coordination of therapies such as immunoglobulin.

Reversal strategies for vitamin K antagonists in acute intracerebral hemorrhage.

OBJECTIVE: There is little evidence to guide treatment strategies for intracerebral hemorrhage on vitamin K antagonists (VKA-ICH). Treatments utilized in clinical practice include fresh frozen plasma (FFP) and prothrombin complex concentrate (PCC). Our aim was to compare case fatality with different reversal strategies. METHODS: We pooled individual ICH patient data from 16 stroke registries in 9 countries (n = 10 282), of whom 1,797 (17%) were on VKA. After excluding 250 patients with international normalized ratio < 1.3 and/or missing data required for analysis, we compared all-cause 30-day case fatality using Cox regression. RESULTS: We included 1,547 patients treated with FFP (n = 377, 24%), PCC (n = 585, 38%), both (n = 131, 9%), or neither (n = 454, 29%). The crude case fatality and adjusted hazard ratio (HR) were highest with no reversal (61.7%, HR = 2.540, 95% confidence interval [CI] = 1.784-3.616, p < 0.001), followed by FFP alone (45.6%, HR = 1.344, 95% CI = 0.934-1.934, p = 0.112), then PCC alone (37.3%, HR = 1.445, 95% CI = 1.014-2.058, p = 0.041), compared to reversal with both FFP and PCC (27.8%, reference). Outcomes with PCC versus FFP were similar (HR = 1.075, 95% CI = 0.874-1.323, p = 0.492); 4-factor PCC (n = 441) was associated with higher case fatality compared to 3-factor PCC (n = 144, HR = 1.441, 95% CI = 1.041-1.995, p = 0.027). INTERPRETATION: The combination of FFP and PCC might be associated with the lowest case fatality in reversal of VKA-ICH, and FFP may be equivalent to PCC. Randomized controlled trials with functional outcomes are needed to establish the most effective treatment.

Early anticoagulation in patients with stroke and atrial fibrillation is associated with fewer ischaemic lesions at 1 month: the ATTUNE study.

BACKGROUND: The optimal time to commence anticoagulation in patients with atrial fibrillation (AF) after ischaemic stroke or transient ischaemic attack (TIA) is unclear, with guidelines differing in recommendations. A limitation of previous studies is the focus on clinically overt stroke, rather than radiologically obvious diffusion-weighted imaging ischaemic lesions. We aimed to quantify silent ischaemic lesions and haemorrhages on MRI at 1 month in patients commenced on early (<4 days) vs late (≥4 days) anticoagulation. We hypothesised that there would be fewer ischaemic lesions and more haemorrhages in the early anticoagulant group at 1-month MRI. METHODS: A prospective multicentre, observational cohort study was performed at 11 Australian stroke centres. Clinical and MRI data were collected at baseline and follow-up, with blinded imaging assessment performed by two authors. Timing of commencement of anticoagulation was at the discretion of the treating stroke physician. RESULTS: We recruited 276 patients of whom 208 met the eligibility criteria. The average age was 74.2 years (SD±10.63), and 79 (38%) patients were female. Median National Institute of Health Stroke Scale score was 5 (IQR 1-12). Median baseline ischaemic lesion volume was 5 mL (IQR 2-17). There were a greater number of new ischaemic lesions on follow-up MRI in patients commenced on anticoagulation ≥4 days after index event (17% vs 8%, p=0.04), but no difference in haemorrhage rates (22% vs 32%, p=0.10). Baseline ischaemic lesion volume of ≤5 mL was less likely to have a new haemorrhage at 1 month (p=0.02). There was no difference in haemorrhage rates in patients with an initial ischaemic lesion volume of >5 mL, regardless of anticoagulation timing. CONCLUSION: Commencing anticoagulation <4 days after stroke or TIA is associated with fewer ischaemic lesions at 1 month in AF patients. There is no increased rate of haemorrhage with early anticoagulation. These results suggest that early anticoagulation after mild-to-moderate acute ischaemic stroke associated with AF might be safe, but randomised controlled studies are needed to inform clinical practice.

Sporadic Creutzfeldt-Jakob disease in Northern Tasmania.

Creutzfeldt-Jakob disease is a rare and incurable form of rapidly progressive neurodegenerative disease. The disease is fatal, and most patients die within 1 year of diagnosis. Clinical features include progressive cognitive dysfunction, delusions or hallucinations, cerebellar ataxia, myoclonus, visual disturbances, extrapyramidal signs and eventually akinetic mutism. Most patients present with varied clinical presentation, hence making it difficult to diagnose at an early stage. We report five cases of sporadic Creutzfeldt-Jakob disease presenting to a Tasmanian hospital in Australia over a period of 52 months. We highlight significant clinical features in all our patients including few atypical presentations, emphasise on relevant clinical biomarkers and illustrate characteristic abnormalities on electroencephalogram and neuroimaging.