Greater Disability Is Associated with Worse Vestibular and Compensatory Oculomotor Functions in People Living with Multiple Sclerosis

Video head impulse test in subacute and chronic stroke survivors: new perspectives for implementation of assessment in rehabilitation

INTRODUCTION

The Video Head Impulse Test (vHIT) is a safe and reliable assessment of peripheral vestibular function. Many studies tested its accuracy in clinical settings for differential diagnosis and quantification of the vestibulo-oculomotor reflex (VOR) in various disorders. However, the results of its application after lesions of the CNS are discordant and have never been studied in rehabilitation. This study aims to assess the VOR performance in a sample of stroke survivors.

METHODS

This is a cross-sectional study on 36 subacute and chronic stroke survivors; only persons with first-ever stroke and able to walk independently, even with supervision, were included. We performed VOR assessments for each semicircular canal by vHIT and balance assessments by the Berg Balance Scale and the MiniBESTest scale.

RESULTS

Two hundred and sixteen semicircular canals were assessed using the Head Impulse paradigm (in both the vertical and horizontal planes), while 72 semicircular canals were assessed using the Suppressed Head Impulse paradigm (horizontal plane). There was a high prevalence of participants with dysfunctional canals, particularly for the left anterior and right posterior canals, which were each prevalent in more than one-third of our sample. Furthermore, 16 persons showed an isolated canal dysfunction. The mean VOR gain for the vertical canals had confidence intervals out of the normal values (0.74-0.91 right anterior; 0.74-0.82 right posterior; 0.73-0.87 left anterior).

CONCLUSION

Our findings suggest that peripheral vestibular function may be impaired in people with stroke; a systematic assessment in a rehabilitation setting could allow a more personalized and patient-centred approach.

Case report: A disconjugate pattern in video head impulse testing hints toward a central cause of acute vertigo

When acute vertigo occurs, the challenge for the medical practitioner lies in the focused assessment to find the cause of its symptoms. Especially in the case of central pathology, a fast diagnosis is essential for therapy. The head impulse, nystagmus, test of skew (HINTS) protocol and the additional video head impulse test (VHIT) can distinguish between central and peripheral vestibular causes in the acute setting and thus help to set the right path for further evaluation and treatment. In this case, a patient with acute onset of vertigo presented with an unusual pattern in the VHIT. Binocular eye tracking showed a disconjugate horizontal vestibulo-ocular reflex (VOR) with severe loss or gain for the adducting eye yet with a lack of corrective saccades. The abducting eye produced a pattern of mild VOR gain loss yet with pronounced corrective saccades. Together with clinical findings that were compatible with internuclear ophthalmoplegia, a probable central lesion in the medial longitudinal fasciculus (MLF) region was suspected. The patient was sent to a tertiary hospital, where the initial MRI was negative, but due to additional neurological symptoms occurring later, multiple lesions in the cervical spine and cerebellum were detected. The hypothesis of an inflammatory demyelinating disease of the central nervous system (CNS) was made. A further workup led to the final diagnosis of neurosarcoidosis. In a retrospective neuroradiologic assessment, an alteration compatible with a non-active demyelinating lesion in the MLF was detected on secondary imaging as a probable cause of the initial pathophysiologic finding. In this report, we aimed to highlight the unusual case of a disconjugate VOR as a distinctive VHIT pattern hinting toward a central cause of acute vertigo that clinicians should be aware of.