Vestibular dysfunction and brain fog


Author/Creator ORCID




Towson University. Department of Audiology, Speech-Language Pathology and Deaf Studies


Citation of Original Publication




Some patients with vestibular loss report experiencing a phenomenon called brain fog. While used relatively common, the exact meaning of the term is still unclear. In this study we attempted to understand the essence of brain fog, its manifestation in patients, and its cofounding factors. Sixty-eight participants with various vestibular diagnoses were recruited through the Johns Hopkins Outpatient Neuro-Otology Center. The participants were divided into two groups, Brain Fog Yes (n = 39) and Brain Fog No (n = 29), based on the presence of brain fog. Both groups partook in a four-part diagnostic questionnaire, consisted of the Patient Health Questionnaire (PHQ-9), Somatic Symptom Scale (SSS-8), General Anxiety Disorder 7-item (GAD7), and Health Anxiety Inventory Short Form (HAI-S). The members of the Brain Fog Yes group also had to complete an adapted Cognitive Disturbance Scale. Finally, each participant underwent a comprehensive vestibular evaluation, including cervical and ocular vestibular evoked myogenic potential tests (c- and oVEMPs), video head impulse test (vHIT), and electronystagmography (ENG). No significant difference was noted between the means of the two groups for age, sex, and racial composition. However, the mean total scores were higher for Brain Fog Yes group for PHQ-9, SSS-8, GAD-7, and HAI-S questionnaires. It was also established that the participants with higher total scores on these questionnaires were more likely to experience greater severity of brain fog. The severity was higher in males compared to females. PHQ-9, SSS-8, and GAD-7 were found to be good predictors of brain fog severity while PQH-9, SSS-8, and HAI-S were good predictors of brain fog presence. Multiple logistic regression indicted that participants with vestibular migraine had odds of having brain fog 37% higher than those with other vestibular diagnoses. Overall, brain fog was defined as a cognitive condition, most frequently associated with such descriptors as “difficulty focusing”, “slow”, “difficulty thinking”, “forgetful”, and “exhausted.”