RESUMO
Objective: To assess the prevalence of each symptom listed in the acronym DISCOHAT (worsening of symptoms in Darkness and/or uneven ground, Imbalance, Supermarket effect, Cognitive complaints, Oscillopsia, Head movements worsen symptoms, Autonomic complaints, and Tiredness) in patients with bilateral vestibulopathy (BVP), compared to patients with unilateral vestibulopathy (UVP). Methods: A descriptive case-control study was performed on BVP and UVP patients who were evaluated for their vestibular symptoms by two of the authors (RvdB, MCG) at a tertiary referral center, between 2017 and 2020. During history taking, the presence of each DISCOHAT symptom was checked and included in the electronic health record. Presence of a symptom was categorized into: "present," "not present," and "missing." Results: Sixty-six BVP patients and 144 UVP patients were included in this study. Prevalence of single DISCOHAT symptoms varied from 52 to 92% in BVP patients and 18-75% in UVP patients. Patients with BVP reported "worsening of symptoms in darkness," "imbalance," "oscillopsia," and "worsening of symptoms with fast head movements" significantly more than UVP patients (p ≤ 0.004). Conclusion: The DISCOHAT acronym is able to capture a wide spectrum of symptoms related to vestibulopathy, while it is easy and quickly to use in clinic. Application of this acronym might facilitate a more thorough and uniform assessment of bilateral vestibulopathy, within and between vestibular clinics worldwide.
RESUMO
OBJECTIVE: To examine the response decline that occurs upon repetitive galvanic vestibular stimulation (GVS) and hampers long-term clinical evaluations. MATERIAL AND METHODS: This was a prospective experimental study conducted in a tertiary referral centre. In a previous study we developed a standardized procedure for reproducible quantification of galvanic-induced body sway (GBS). The most reproducible responses were found using a continuous 1-cosinusoidal stimulus (0.5 Hz; 2 mA) preceded by a pre-habituating stimulus. This binaural prestimulation reduced the short-term (<5 min) response decline to a non-significant level. The response decline without prestimulation was interpreted as habituation to the galvanic stimulation. In the present study we evaluated possible long-term habituation to GVS, which may hamper longitudinal clinical evaluations. Possible long-term habituation using the short-term habituating prestimulus concept was studied by quantifying GBS in 40 subjects at 5 consecutive time points. Subjects were subdivided into four equal groups who were tested with four different time intervals between the five measurements, ranging from 1 day to 2 weeks. RESULTS: The absolute test results did not vary with the time interval (p=0.217; repeated measurement test). Irrespective of the time interval between the tests, habituation occurred after the first stimulation and remained stable at all consecutive measurements. GVS habituation did not depend on either the degree of daily life activity (moderate practice of sport) or on gender. CONCLUSION: The current protocol, using a prehabituating binaural stimulus, showed that reproducible assessment of the GVS over a time course of days to weeks was possible starting from the second test.
