Background: Aetiology of transient global amnesia (TGA) remains uncertain, though many have been proposed, including ischaemic, migrainous or epileptic pathologies. Methods: We attempted to determine risk factors for TGA, as well as prognostic factors that may cause recurrence. We evaluated clinical history, family history and magnetic resonance diffusion-weighted imaging (DWI) studies of 93 prospective patients with TGA. Patients were followed from 2004 to 2016. Fifteen of 93 (16%) patients experienced a recurrence of TGA. Results: Among precipitating events, physical activities inducing Valsalva-like manoeuvres were most common, followed by emotional stress. Eighty-four patients had possible comorbidities or risk factors for TGA, though no single risk factor was ubiquitous. Risk factors associated with recurrence were head injury (isolated vs. recurrent, 16.7% vs. 53.5%, p < 0.01), depression (isolated vs. recurrent, 15.4% vs 46.7%, p = 0.01) and family history of dementia (isolated vs. recurrent, 20.5% vs. 46.7%, p = 0.03). Of 15 patients with confirmed recurrent TGA, two developed dementia and four subjective memory impairment. DWI lesions were observed in 24 patients and were located anywhere within the hippocampus. Conclusions: DWI lesions were not significantly associated with outcomes (recurrence, subjective memory impairment, dementia). We have found that depression, previous head injury and family history of dementia may predict TGA recurrence.

Aim: To assess the role of genetic factors, other than the CAG repeat length, on the development of Huntington’s disease (HD) in an isolated Caucasian population in the south-west of Western Australia. Methods: 114 patients with symptomatic HD according to the Unified HD Rating Scale research criteria were examined along with 51 control patients. The length of the CAG repeat sequence in the IT15 gene and the adjacent CCG and Δ2642 polymorphisms were determined by polymerase chain reaction along with common genotypes of the angiotensin-converting enzyme (ACE) and apolipoprotein E (APOE) genes. Results: The CAG expansion was associated with age of onset and the development of neurological dysfunction. We found no effect of the expanded CCG allele on age of onset, neurological dysfunction or the size of the CAG expansion. We observed a twofold increase in the Δ2642 polymorphism and the risk of developing symptomatic HD which was not significant (OR 2.06; 95% CI 0.60–7.07). The presence of an APOE Ε4 allele was associated with an increased risk of HD which was not significant either (OR 1.04–1.73; 95% CI 0.10–10.68). ACE genotypes showed no association with risk factors for the disease. Conclusion: In our study of a geographically isolated Caucasian HD population in the south-west of Western Australia we have not observed that the expanded CCG allele, the Δ2642 polymorphism, the APOE Ε4 allele and ACE genotypes are associated with an increased risk for the development of symptomatic HD.

Background: Young onset dementia (YOD) is a major diagnostic and management problem. Methods: We set out to explore if electroencephalography (EEG) might be useful in the diagnosis of young onset Alzheimer’s disease (YOAD) and young onset frontotemporal dementia (YOFTD). The ARTEMIS project is a 25-year prospective study of YOD based in Perth, Western Australia. 231 participants were included: YOAD: n = 103, YOFTD: n = 28, controls: n = 100. EEGs were performed prospectively, with 30-minute recording time for each subject, without knowledge of diagnosis or other diagnostic data. Results: 80.9% of patients with YOD had abnormal EEGs (P < 0.00001). Slow wave changes were more frequent in YOAD that YOFTD (P < 0.00001), but no difference in the frequency of epileptiform activity (P = 0.32), with 38.8% of YOAD and 28.6% of YOFTD patients having epileptiform activity. Slow wave changes were more generalized in YOAD (P = 0.001). Slow wave changes and epileptiform activity were not sensitive to the diagnosis of YOD, but highly specific (97–99%). The absence of slow wave changes and epileptiform activity had a 100% negative predictive value and likelihood radio 0.14 and 0.62 respectively, meaning that those without slow wave changes or epileptiform activity had low probability of having YOD. No relationship was established between EEG findings and the patient’s presenting problem. Eleven patients with YOAD developed seizures during the study, and only one with YOFTD. Conclusions: The EEG is highly specific for the diagnosis of YOD with the absence of slow wave changes and epileptiform phenomena making the diagnosis unlikely, with 100% negative predictive value and with low probability for the dementia diagnosis.

Neuromyelitis optica is a rare, severe inflammatory demyelinating disease of the central nervous system, previously described as affecting only the optic nerve and spinal cord. Since the discovery of a highly specific autoantibody, anti-aquaporin-4, lesions are now recognized outside these regions. We report a man with severe, debilitating symptoms resulting from a symptomatic lesion within the diencephalon, manifesting with abnormal circadian rhythms, autonomic dysfunction, behavioral disturbance, and complex visual hallucinations. The patient reported seeing nonexistent small people and animals, streaks of color across people’s faces, movement of objects and facial features, water cascading down walls, bright spots, and writing appearing as hieroglyphics. His centrally driven sick sinus syndrome required insertion of a permanent cardiac pacemaker. We have been able to suppress his disease activity with methotrexate for 30 months. We review the literature on patients with positive anti-aquaporin-4 serology and dysregulation of hypothalamic function, to provide evidence that the clinical manifestations can include complex visual phenomena.