Vestibular Rehabilitation to the Patients With Vestibular Migraine and Vestibular Neuritis

Background It is not yet claried the effect of vestibular rehabilitation on patients with vestibular migraine (VM) . Aims/Objectives In this study, we aimed to compare the effect of vestibular rehabilitation on patients with VM and those in the chronic stage of vestibular neuritis (VN). Material and Methods A total of 26 patients with VM and 31 patients in the chronic stage of VN who were treated. All patients underwent an in-hospitalized vestibular rehabilitation program. A variety of data including the Dizziness Handicap Inventory (DHI), POMS, and posturography were compared. Before treatment, there was no signicant difference in the parameters between the two groups, except for a higher confusion score of Prole of Mood States (POMS) in the VM group. In both groups, the DHI score signicantly improved. In the VM group, the confusion score of POMS, physical component score (PCS) of SF-8, and some parameters in posturography signicantly improved. In the VN group, anxiety, depression, and PCS of SF-8 signicantly improved.


Dizziness Handicap Inventory
The Dizziness Handicap Inventory (DHI) [11] is a standard questionnaire that quantitatively evaluates the degree of handicap in the daily lives of patients with vestibular disorders and consists of 25 questions. The total score ranges from 0 (no disability) to 100 (severe disability).

State-Trait Anxiety Inventory
The State-Trait Anxiety Inventory (STAI) [12] is a self-reported questionnaire consisting of 40 questions, comprising a state anxiety subscale with 20 items and a trait anxiety subscale with 20 items. Each item of the STAI assesses how respondents ''generally'' feel regarding each statement (e.g., ''I feel at ease'') on a scale of 1 (almost never) to 4 (almost always).

Self-Rating Depression Scale
The Self-Rating Depression Scale (SDS), designed by Zung in 1965 [13], is generally considered a reliable instrument for measuring depressive symptoms in primary care. It is a self-reported, 20-item questionnaire. Item responses are rated from 1 to 4, with higher scores corresponding to more frequent symptoms.

Pro le of Mood States (POMS)
The POMS is a psychological rating scale used to assess transient, distinct mood states. The POMS measures six different dimensions of mood swings over a period of time. These include tension or anxiety, anger or hostility, vigor or activity, fatigue or inertia, depression or dejection, and confusion or bewilderment.
A ve-point scale ranging from "not at all" to "extremely" is administered by experimenters to patients for assessing their mood state.

Japanese version of the Medical Outcomes Study 8-items Short Form Health Survey
Health-related QOL was evaluated using the Japanese version of the Medical Outcomes Study 8-items Short Form Health Survey (SF-8) questionnaire, the validity and reliability of which have already been con rmed [14]. SF-8 comprises eight items -physical functioning, role limitation due to physical problems, body pain, general health, vitality, social functioning, role limitation due to emotional problems, and mental health. The physical health component summary score (PCS) and mental health component summary score (MCS) were measured using the norm-based scoring method, which is based on a large-scale population study conducted in Japan [15]. Higher scores on these subscales indicate better health-related QOL.

Measurement of the gravity center uctuation
The measurement of the gravity center uctuation for objective assessment of the dizziness severity was performed using a stabilometer (G-5000, Anima Corp., Tokyo, Japan), and the total length of path (LNG) and environmental area (ENV) during eye-opening/closing. Forty-nine patients (12 males and 37 females, mean age = 54.1±16.3 years) remained in the analysis. The participants in this study comprised 25 patients with VM and 24 patients with VN. There was no signi cant difference in age between the groups (t[41.6] = 1.3, p = 0.21). Some patients did not provide any data regarding STAI responses (valid data: N = 48), SDS responses (valid data: N = 47), POMS responses (valid data: N = 47), SF-8 responses (valid data: N = 46), and LNG and ENV during eye opening and closing (valid data: N = 46). In cases where the participant fell, measurement of their center of gravity uctuation was treated as missing data.
Two-way ANOVA results Table 1 shows the comparison between groups and time points for all variables using two-way repeated measures ANOVA. There were signi cant main effects of group on the trait scale of STAI and the SDS score (VM > VN) and signi cant main effects of time on the DHI score, state and trait scores of STAI, SDS score, trait-anxiety, depression, anger-hostility, confusion, and total mood disturbance scores of POMS, the PCS and MCS scores of SF-8, LNG during eye closing, and ENV during eye closing (SF-8: time 1 < time 2, other variables: time 1 > time 2). Regarding the confusion score of POMS, there was a signi cant interaction between group and time. The post hoc test showed that the confusion score at time 1 in the VM group was signi cantly higher than that in the VN group and that the confusion score at time 2 was signi cantly lower than that at time 1 only in the VM group.

Discussion
In this study, we successfully indicated that the group undergoing vestibular rehabilitation showed improvement almost all parameters of dizziness, emotions, and QOL for both VM and VN. The improvement of physical and psychological symptoms in patients with VM supports our previous results [6]. Additionally, our provides new ndings on the effect on anger, confusion, or QOL, which were not investigated in a previous study [6]. Migraine or VM is closely associated with psychosocial stress and should be assessed using both physical and psychological measurements.
The mechanism of e cacy of vestibular rehabilitation in patients with VM can be explained by the physiological background of the association between vestibular function and headache. Some studies have proposed that the mechanism underlying vestibular dysfunction related to migraine is a parallel activation of the vestibular and cranial nociceptive pathways [8]. Nociceptive and vestibular afferents with neurochemical similarities, including the expression of serotonin, capsaicin, and purinergic receptors [8], converge in brainstem structures such as the parabrachial nucleus, raphe nuclei, and locus coeruleus, and these structures play an important role in modulating the sensitivity of pain pathways [8]. Thus, vestibular symptoms may have a biologically close association with headaches.
In this study, the "confusion" score, a subscale of the POMS, indicated the most prominent difference between patients with VM and patients with VN regarding the e cacy of vestibular rehabilitation. The migraineurs reported signi cantly greater scores on the confusion-bewilderment subscale of the POMS [17]. We also found that patients with VM had a higher score of confusion of POMS at baseline. Additionally, the confusion score improved with vestibular