Bilateral Vestibular Failure May Improve With Treatment of the Underlying Condition: A Report of 2 Cases.

Introduction: Bilateral vestibular failure (BVF) is an uncommon condition with numerous etiologies. It causes chronic oscillopsia and imbalance and is usually irreversible. We report 2 cases of BVF due to unusual causes, both of which improved with treatment of the underlying condition.

A Māori specific RFC1 pathogenic repeat configuration in CANVAS, likely due to a founder allele.

Cerebellar ataxia with neuropathy and bilateral vestibular areflexia syndrome (CANVAS) is a recently recognized neurodegenerative disease with onset in mid- to late adulthood. The genetic basis for a large proportion of Caucasian patients was recently shown to be the biallelic expansion of a pentanucleotide (AAGGG)n repeat in RFC1. Here, we describe the first instance of CANVAS genetic testing in New Zealand Māori and Cook Island Māori individuals.

Inherited RORB pathogenic variants: Overlap of photosensitive genetic generalized and occipital lobe epilepsy.

Variants in RORB have been reported in eight individuals with epilepsy, with phenotypes ranging from eyelid myoclonia with absence epilepsy to developmental and epileptic encephalopathies. We identified novel RORB variants in 11 affected individuals from four families. One was from whole genome sequencing and three were from RORB screening of three epilepsy cohorts: developmental and epileptic encephalopathies (n = 1021), overlap of generalized and occipital epilepsy (n = 84), and photosensitivity (n = 123).

Central mimics of benign paroxysmal positional vertigo: an illustrative case series.

Benign paroxysmal positional vertigo (BPPV) is the most common peripheral vestibular disorder that is diagnosed based solely on clinical findings. Rarely, central lesions can present with positional vertigo and nystagmus, mimicking BPPV. Recognised red flags that may help distinguish central mimics from BPPV include the presence of additional neurological symptoms and signs, atypical nystagmus patterns, and the absence of a sustained response to repositioning manoeuvres.

Gentamicin vestibulotoxicity with modern systemic dosing regimens: a prospective study using video-oculography.

To determine the incidence of gentamicin vestibulotoxicity with current dosing regimens, and to evaluate the feasibility of routine video-oculography on all patients given gentamicin. In this prospective incidence study serial horizontal vestibulo-ocular reflex (HVOR) gain measurements were recorded using video-oculography on adult inpatients receiving intravenous gentamicin. The primary outcome was the proportion of patients developing impairment of their HVOR gain.

Bioinformatics-Based Identification of Expanded Repeats: A Non-reference Intronic Pentamer Expansion in RFC1 Causes CANVAS.

Genomic technologies such as next-generation sequencing (NGS) are revolutionizing molecular diagnostics and clinical medicine. However, these approaches have proven inefficient at identifying pathogenic repeat expansions. Here, we apply a collection of bioinformatics tools that can be utilized to identify either known or novel expanded repeat sequences in NGS data.

A Novel CACNA1A Nonsense Variant [c.4054C>T (p.Arg1352)] Causing Episodic Ataxia Type 2.

Episodic ataxia is a heterogenous group of uncommon neurological disorders characterised by recurrent episodes of vertigo, dysarthria, and ataxia for which a variety of different genetic variations have been implicated. Episodic ataxia type two (EA2) is the most common and also has the largest number of identified causative genetic variants. Treatment with acetazolamide is effective in improving symptoms, so accurate diagnosis is essential.

Misleading signs in acute vertigo.

The acute vestibular syndrome is common and usually has a benign cause. Sometimes, however, even experienced neurologists can find it difficult to determine the cause clinically. Furthermore, neuroimaging is known to be insensitive.

Peripheral nerve ultrasound in Friedreich ataxia.

Introduction: Sensory impairment in Friedreich ataxia (FRDA) is generally accepted as being due to a ganglionopathy. The degree of contribution from axonal pathology remains a matter of debate. Nerve ultrasound may be able to differentiate these processes.

Comparison of the video head impulse test with the caloric test in patients with sub-acute and chronic vestibular disorders.

The aim of this prospective register-based study was to compare video Head Impulse Tests (vHIT) with caloric tests on 173 patients assessed by a tertiary Neurology referral centre who had been referred for investigation of dizziness or vertigo and whose symptom duration was one month or longer. Abnormal vHIT was defined as angular velocity gain (peak eye velocity/peak head velocity) less than 0.79 at 80 ms and 0.

Peripheral nerve ultrasound in cerebellar ataxia neuropathy vestibular areflexia syndrome (CANVAS).

Introduction: We report preliminary findings of nerve ultrasound in patients with cerebellar ataxia neuropathy vestibular areflexia syndrome (CANVAS) who have sensory impairment due to dorsal root ganglionopathy.

Methods: The ultrasound cross-sectional area (CSA) of median and ulnar nerves of 7 CANVAS patients was compared with 7 age- and gender-matched controls and with the mean CSA of our reference population.

Results: The nerve CSA of CANVAS patients was significantly smaller than that of controls at all sites (P < 0.

Age dependent normal horizontal VOR gain of head impulse test as measured with video-oculography.

Background: The head impulse test (HIT) is a recognised clinical sign of the high frequency vestibulo-ocular reflex (VOR), which can be quantified with video-oculography. This measures the VOR gain as the ratio of angular eye velocity to angular head velocity. Although normative data is available for VOR gain with video-oculography, most normal studies in general include small numbers of subjects and do not include analysis of variation of VOR gain with age.

Autonomic dysfunction is a major feature of cerebellar ataxia, neuropathy, vestibular areflexia 'CANVAS' syndrome.

Cerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS) is a recently recognized neurodegenerative ganglionopathy. Prompted by the presence of symptomatic postural hypotension in two patients with CANVAS, we hypothesized that autonomic dysfunction may be an associated feature of the syndrome. We assessed symptoms of autonomic dysfunction and performed autonomic nervous system testing among 26 patients from New Zealand.

Dorsal root ganglionopathy is responsible for the sensory impairment in CANVAS.

Objective: To elucidate the neuropathology in cerebellar ataxia with neuropathy and bilateral vestibular areflexia syndrome (CANVAS), a novel cerebellar ataxia comprised of the triad of cerebellar impairment, bilateral vestibular hypofunction, and a peripheral sensory deficit.

Method: Brain and spinal neuropathology in 2 patients with CANVAS, together with brain and otopathology in another patient with CANVAS, were examined postmortem.

Results: Spinal cord pathology demonstrated a marked dorsal root ganglionopathy with secondary tract degeneration.

The p.Ala510Val mutation in the SPG7 (paraplegin) gene is the most common mutation causing adult onset neurogenetic disease in patients of British ancestry.

The c.1529C >T change in the SPG7 gene, encoding the mutant p.Ala510Val paraplegin protein, was first described as a polymorphism in 1998.

Are there diurnal variations in the results of the Dix-Hallpike manoeuvre?

This study examines diurnal variation in the result of the Dix-Hallpike manoeuvre when testing for benign paroxysmal positional vertigo in a randomised crossover study of the order of diagnostic testing in a community out-reach clinic for a tertiary neurological centre in Wellington, New Zealand. Study participants were adults referred for physiotherapy treatment. Dix-Hallpike manoeuvres were performed to both ears, and groups were randomly allocated to have a morning, then afternoon, sequence of testing or vice versa.

Cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS): a review of the clinical features and video-oculographic diagnosis.

The association of bilateral vestibulopathy with cerebellar ataxia was first reported in 1991 and delineated as a distinct syndrome with a characteristic and measurable clinical sign--an absent visually enhanced vestibulo-ocular reflex--in 2004. We reviewed 27 patients with this syndrome and show that a non-length-dependent sensory deficit with absent sensory nerve action potentials is an integral component of this syndrome, which we now call "cerebellar ataxia with neuropathy and bilateral vestibular areflexia syndrome" (CANVAS). All patients had brain MRI and 22/27 had evidence of cerebellar atrophy involving anterior and dorsal vermis, as well as the hemispheric crus I.

Carotid endarterectomy: a Southern North Island regional consensus statement.

Aims: The aim of this project was to employ interdepartmental and cross district health board collaboration to reach a regional consensus on the management of patients who may benefit from carotid endarterectomy.

Methods: All regional stroke physicians, neurologists, and vascular surgeons met to review relevant literature and local audits and to discuss best management strategies suited to the region.

Results: A consensus statement was agreed upon and is presented here along with a summary of the supporting scientific evidence.

Recurrent anterior chamber hemorrhage from an intraocular lens simulating amaurosis fugax.

Uveitis-glaucoma-hyphema syndrome is a rare late complication of anterior segment surgery. We present 2 unusual cases of this syndrome that were mistakenly diagnosed as amaurosis fugax, leading to contraindicated treatment. These cases illustrate the need for ophthalmologic examination during an episode of symptoms.

Brainstem lesions presenting with nausea and vomiting.

Positional vomiting is an important alerting sign for the presence of a brainstem central nervous system (CNS) lesion. Failure to identify another cause of protracted vomiting should prompt consideration of a CNS cause.