Clinical features of persistent postural-perceptual dizziness with isolated otolith dysfunction as revealed by VEMP and vHIT findings

A self-assessment scale has been developed and found to be a reliable instrument for detecting states of depression and anxiety in the setting of an hospital medical outpatient clinic. The anxiety and depressive subscales are also valid measures of severity of the emotional disorder. It is suggested that the introduction of the scales into general hospital practice would facilitate the large task of detection and management of emotional disorder in patients under investigation and treatment in medical and surgical departments.

Conventional vestibulometric techniques are inadequate for quantifying the impact of dizziness on everyday life. The 25-item Dizziness Handicap Inventory (DHI) was developed to evaluate the self-perceived handicapping effects imposed by vestibular system disease. The development of the preliminary (37 items) and final versions (25 items) of the DHI are described. The items were subgrouped into three content domains representing functional, emotional, and physical aspects of dizziness and unsteadiness. Cronbach's alpha coefficient was employed to measure reliability based on consistency of the preliminary version. The final version of the DHI was administered to 106 consecutive patients and demonstrated good internal consistency reliability. With the exception of the physical subscale, the mean values for DHI scale scores increased significantly with increases in the frequency of dizziness episodes. Test-retest reliability was high.

This paper presents diagnostic criteria for persistent postural-perceptual dizziness (PPPD) to be included in the International Classification of Vestibular Disorders (ICVD). The term PPPD is new, but the disorder is not. Its diagnostic criteria were derived by expert consensus from an exhaustive review of 30 years of research on phobic postural vertigo, space-motion discomfort, visual vertigo, and chronic subjective dizziness. PPPD manifests with one or more symptoms of dizziness, unsteadiness, or non-spinning vertigo that are present on most days for three months or more and are exacerbated by upright posture, active or passive movement, and exposure to moving or complex visual stimuli. PPPD may be precipitated by conditions that disrupt balance or cause vertigo, unsteadiness, or dizziness, including peripheral or central vestibular disorders, other medical illnesses, or psychological distress. PPPD may be present alone or co-exist with other conditions. Possible subtypes await future identification and validation. The pathophysiologic processes underlying PPPD are not fully known. Emerging research suggests that it may arise from functional changes in postural control mechanisms, multi-sensory information processing, or cortical integration of spatial orientation and threat assessment. Thus, PPPD is classified as a chronic functional vestibular disorder. It is not a structural or psychiatric condition.