Diagnosis, differential diagnosis and misdiagnosis of Susac syndrome.

BACKGROUND AND PURPOSE: Susac syndrome (SuS) is an inflammatory condition of the brain, eye and ear. Diagnosis can be challenging, and misdiagnosis is common. METHODS: This is a retrospective review of the medical records of 32 adult patients from an Australasian cohort of SuS patients. RESULTS: An alternative diagnosis prior to SuS was made in 30 patients (94%) with seven patients receiving two or more diagnoses. The median time to diagnosis of SuS was 3 months (range 0.5-100 months). The commonest misdiagnoses were migraine in 10 patients (31%), cerebral vasculitis in six (19%), multiple sclerosis in five (16%) and stroke in five (16%). Twenty-two patients were treated for alternative diagnoses, 10 of whom had further clinical manifestations prior to SuS diagnosis. At presentation seven patients (22%) met criteria for definite SuS, 19 (59%) for probable SuS and six (19%) for possible SuS. Six patients (19%) presented with brain-eye-ear involvement, 14 with brain-ear (44%), six with brain-eye (19%) and six (19%) with only brain involvement. In patients with the complete triad of symptoms the median delay to diagnosis was 3 months (range 1-9 months) compared to 5.25 months (range 0.5-100 months) for patients with encephalopathy and ocular symptoms at presentation. CONCLUSIONS: Susac syndrome patients are frequently misdiagnosed at initial presentation, despite many having symptoms or radiological features that are red flags for the diagnosis. Delayed diagnosis can lead to patient morbidity. The varied ways in which SuS can present, and clinician failure to consider or recognize SuS, appear to be the main factors leading to misdiagnosis.

Acute transverse myelitis in COVID-19 infection.

A 60-year-old man presented to hospital with bilateral lower limb weakness, urinary retention and constipation. He had been diagnosed with COVID-19 10 days prior. Clinical examination revealed global weakness, increased tone, hyperreflexia and patchy paresthesia in his lower limbs bilaterally. Preliminary blood tests performed revealed a mildly elevated C reactive protein and erythrocyte sedimentation rate but was otherwise unremarkable. MRI scan of his whole spine demonstrated hyperintense T2 signal centrally from T7 to T10, suggestive of acute transverse myelitis. A lumbar puncture showed elevated protein count but normal glucose and white blood cell count. Serological testing for other viruses was negative. His neurological symptoms improved significantly after treatment with intravenous methylprednisone. This case highlights a potential neurological complication of COVID-19 infection.

The neuro-otology of Susac syndrome.

OBJECTIVE: We characterised the clinical and neuro-otological characteristics of patients with Susac syndrome. METHODS: The medical records of 30 patients with Susac syndrome were reviewed for details of their clinical presentation and course, neuro-otological symptoms, investigation results including audiology and vestibular function tests, treatment and outcomes. RESULTS: Our findings demonstrate that 29 of our 30 patients with Susac syndrome developed neuro-otological symptoms such as hearing loss, disequilibrium, tinnitus or vertigo during their disease course. Hearing loss was the most common neuro-otological symptom occurring in 93% of patients. A rising configuration of low-frequency greater than the high-frequency sensorineural hearing loss was the most characteristic finding on audiological testing (37% of reviewed audiograms). Disproportionately poor speech discrimination was identified in 20% of cases, and one case demonstrated a retrocochlear pattern on electrophysiological testing. Four patients required hearing aids and a further two patients required a cochlear implant due to severe hearing loss. Two out of two treated patients had improvements in hearing after the prompt administration of corticosteroids, indicating the potential for recoverable hearing loss if relapses are treated early. Effects on vestibular function were variable in ten patients who were tested, with most showing preservation of function despite significant hearing loss. CONCLUSIONS: Neuro-otological symptoms in Susac syndrome are almost universal. In the correct clinical context, a rising configuration of low to high-frequency sensorineural hearing loss should prompt consideration of Susac syndrome. Treatment of inner ear symptoms in Susac syndrome requires further research as early immunotherapy may be beneficial.

Varicella-zoster meningitis in an immunocompetent young man presenting with a painless erythematous rash.

A 32-year-old man presented with a 7-day history of generalised headache, intermittent fever, emesis and diarrhoea. Four days after symptom onset, he developed a vesicular rash on his medial left thigh, without associated pain, paraesthesia or pruritus. He had no significant past medical history, and no HIV risk factors. He was presumed to have enteroviral meningitis and was commenced on supportive therapy. Lumbar puncture was performed and cerebrospinal fluid (CSF) analysis revealed a lymphocytic pleocytosis. While awaiting CSF serology, the formation of a new vesicle was noted at the site of the rash and was swabbed. Results for both the CSF and vesicle swab returned positive for varicella-zoster virus (VZV) confirming concurrent VZV meningitis with atypical painless herpes zoster in a young immunocompetent patient. He was initiated on intravenous acyclovir and made a full recovery after 2 weeks of treatment.

Disability in older adults across the continuum of cognitive decline: unique contributions of depression, sleep disturbance, cognitive deficits and medical burden.

OBJECTIVES: Disability in older adults is associated with a need for support in work, education, and community activities, reduced independence, and poorer quality of life. This study examines potential determinants of disability in a clinical sample of older adults across the continuum of cognitive decline, including sociodemographic, medical, psychiatric, and cognitive factors. DESIGN: This is a cross-sectional study. SETTING: Participants were recruited from a specialty clinic for adults "at risk" of or with early dementia (including subjective cognitive complaints, mild cognitive impairment, and early dementia). PARTICIPANTS: Four hundred forty-two older adults (mean age = 67.11, SD = 9.33) underwent comprehensive medical, neuropsychological, and mood assessments. MEASUREMENTS: Disability was assessed via the self-report World Health Organization Disability Assessment Schedule 2.0. A stepwise (forward) linear regression model was computed to determine factors that contribute to disability within this group. RESULTS: Depressive symptoms were the largest predictor, uniquely explaining 31.8% of the variance. Other contributing factors in the model included younger age, medical burden, and sleep quality, with all factors together accounting for a total of 50.4% of the variance in disability. Cognitive variables did not contribute to the model. CONCLUSIONS: Depressive symptoms account for a significant portion of the variance in disability, but other factors such as age, medical burden and sleep quality are also important contributors in older adults across the continuum of cognitive decline. The relative association of these variables with disability appears to differ for older (≥65 years) relative to younger (<65 years) participants. Given the relationship between disability and these risk factors, an integrative and multidisciplinary approach to risk reduction will likely be most effective, with potential carry over effects for physical and mental health.

Examining Internet and eHealth Practices and Preferences: Survey Study of Australian Older Adults With Subjective Memory Complaints, Mild Cognitive Impairment, or Dementia.

BACKGROUND: Interest in electronic health (eHealth) technologies to screen for and treat a variety of medical and mental health problems is growing exponentially. However, no studies to date have investigated the feasibility of using such e-tools for older adults with mild cognitive impairment (MCI) or dementia. OBJECTIVE: The objective of this study was to describe patterns of Internet use, as well as interest in and preferences for eHealth technologies among older adults with varying degrees of cognitive impairment. METHODS: A total of 221 participants (mean age=67.6 years) attending the Healthy Brain Ageing Clinic at the University of Sydney, a specialist mood and memory clinic for adults ≥50 years of age, underwent comprehensive clinical and neuropsychological assessment and completed a 20-item self-report survey investigating current technology use and interest in eHealth technologies. Descriptive statistics and Fisher exact tests were used to characterize the findings, including variability in the results based on demographic and diagnostic factors, with diagnoses including subjective cognitive impairment (SCI), MCI, and dementia. RESULTS: The sample comprised 27.6% (61/221) SCI, 62.0% (137/221) MCI, and 10.4% (23/221) dementia (mean Mini-Mental State Examination=28.2). The majority of participants reported using mobile phones (201/220, 91.4%) and computers (167/194, 86.1%) routinely, with most respondents having access to the Internet at home (204/220, 92.6%). Variability was evident in the use of computers, mobile phones, and health-related websites in relation to sociodemographic factors, with younger, employed respondents with higher levels of education being more likely to utilize these technologies. Whereas most respondents used email (196/217, 90.3%), the use of social media websites was relatively uncommon. The eHealth intervention of most interest to the broader sample was memory strategy training, with 82.7% (172/208) of participants reporting they would utilize this form of intervention. Preferences for other eHealth interventions varied in relation to educational level, with university-educated participants expressing greater interest in interventions related to mood (P=.01), socialization (P=.02), memory (P=.01), and computer-based exercises (P=.046). eHealth preferences also varied in association, with diagnosis for interventions targeting sleep (P=.01), nutrition (P=.004), vascular risk factors (P=.03), and memory (P=.02). CONCLUSIONS: Technology use is pervasive among older adults with cognitive impairment, though variability was noted in relation to age, education, vocational status, and diagnosis. There is also significant interest in Web-based interventions targeting cognition and memory, as well as other risk factors for cognitive decline, highlighting the urgent need for the development, implementation, and study of eHealth technologies tailored specifically to older adults, including those with MCI and early dementia. Strategies to promote eHealth use among older adults who are retired or have lower levels of education will also need to be considered.

Risk factor profile in Chinese-Australian stroke patients living in Sydney.

AIM: To examine and compare stroke risk factors and their management in stroke patients of Chinese descent versus English-speaking background (ESB)-Australian patients. METHODS: Cohort study. Fifty-one Chinese-Australians and 119 ESB-Australians who were admitted to hospitals within Sydney metropolitan area with a recent acute ischaemic or haemorrhagic stroke were recruited. RESULTS: Chinese-Australian patients tended to have a favourable smoking (0% current smokers vs 15%, P = 0.036) and drinking (5% current medium/heavy drinkers vs 17%, P = 0.005) pattern compared with the Australian patients. The prevalence of diabetes mellitus was higher in Chinese-Australians (31% vs 10%, P = 0.003). The management of hypertension and atrial fibrillation (AF) in Chinese-Australians was suboptimal (19% untreated hypertension vs 8%, P = 0.102; 78% AF not on Warfarin vs 51%, P = 0.264). CONCLUSION: The findings of this study suggest that targeting specific stroke prevention strategies may be useful for Chinese-Australians. Larger-scale studies need to be conducted to confirm these findings.

Axonal function in a family with episodic ataxia type 2 due to a novel mutation.

Episodic ataxia type 2(EA-2) is a rare, autosomal dominant disorder characterised by recurrent episodes of ataxia and dysarthria,due to mutations in the CACNA1A gene on chromosome 19 encoding voltage-dependent Ca2+ channels. The aim of the present study was to explore whether axonal membrane properties, assessed using nerve excitability techniques, were abnormal in patients with EA-2 . Nerve excitability techniques were applied to the median nerve of three individuals from three generations of a single family, all of whom had typical features of EA-2. This family was found to have a novel mutation at codon 1451 of the Ca2+ channel alpha 1A subunit. Nerve excitability testing demonstrated significant abnormalities,with all patients outside the normal 95 % confidence limits in having a high rheobase and reduced early hyperpolarizing threshold electrotonus. On average there were also significant reductions in refractoriness,late sub excitability and early depolarizing threshold electrotonus. Mathematical modelling indicated that a similar pattern of abnormalities may result from a reduced voltage dependence of slow K+ channels (KCNQ channels). There are significant and distinctive changes in peripheral nerve excitability in EA-2 patients,which are presumably induced indirectly. These findings raise the possibility that excitability testing may prove a convenient screening test for patients with this suspected channelopathy.

The vestibular dysfunction and anxiety disorder interface: a descriptive study with special reference to the elderly.

Vestibular abnormalities co-existing with anxiety disorders are not uncommon and there has been a renewal of interest in recent times. Although well known over centuries, there is often a delay in the recognition of this relationship by the primary care physician and the specialist alike. Dizziness embracing vertigo, unsteadiness and imbalance are common in the elderly, so is generalized anxiety disorder, which is a common psychiatric problem in later life. This is a retrospective study of eight patients with vestibular symptoms and an anxiety disorder present over several years with lack of awareness of their relationship. The diagnoses of the anxiety disorders were based on the Diagnostic and Statistical Manual (DSM-IV) criteria and the effect of treatment measured on a clinician-based impression interview. There was one male and seven females and the mean age was 72 years. Apart from the vestibular symptoms present in all the patients, the anxiety disorders comprised, generalized anxiety disorder in three, panic attacks in five and with agoraphobia in three. Four patients had hyperventilation, one sleep apnea, and two somatization disorders. They had all presented to clinicians in different disciplines and had had several investigations. Five had been treated in this study with alprazolam and three with citalopram, with modest to good results. Two had rehabilitation therapy as well. The cases described mirror the well-documented co-existence of vestibular and anxiety disorders together with hyperventilation and sleep apnea. The positive findings associated with vestibular dysfunction need recognition in addition to the non-specific psychiatric and behavioral symptoms. We emphasize this relationship and review the literature to alert the clinician.