Test Batteries and the Diagnostic Algorithm for Chronic Vestibular Syndromes

Objective: To develop a diagnostic algorithm for chronic vestibular syndromes by determining significant items that differ among diagnoses.Methods: Two hundred thirty-one patients with chronic vestibular syndromes lasting for >3 months were included. Full vestibular tests and questionnaire surveys were performed: bithermal caloric test, cervical and ocular vestibular-evoked myogenic potential assessment, video head impulse test (vHIT), posturography, rotatory chair test, dizziness handicap inventory, hospital anxiety and depression scale (HADS), and Niigata persistent postural-perceptual dizziness (PPPD) questionnaire (NPQ). Differences in each item of the vestibular tests/questionnaires/demographic data were tested among the diagnoses. A receiver operating characteristic (ROC) curve was created for the significant items. The value that provided the best combination of sensitivity/specificity on the ROC curve was adopted as a threshold for diagnosing the targeted disease. Multiple diagnostic algorithms were proposed, and their diagnostic accuracy was calculated.Results: There were 92 patients with PPPD, 44 with chronic dizziness due to anxiety (CDA), 31 with unilateral vestibular hypofunction (UVH), 37 with undifferentiated dizziness (UD), and 27 with other conditions. The top four diagnoses accounted for 88% of all chronic vestibular syndromes. Five significant items that differed among the four diseases were identified. The visual stimulation and total NPQ scores were significantly higher in the patients with PPPD than in those with UVH and UD. The percentage of canal paresis (CP %) was significantly higher in the patients with UVH than in those with PPPD, CDA, and UD. The patients with CDA were significantly younger and had higher anxiety scores on the HADS (HADS-A) than those with UVH and UD. Moreover, catch-up saccades (CUSs) in the vHIT were more frequently seen in the patients with UVH than in those with PPPD. The most useful algorithm that tested the total and visual stimulation NPQ scores for PPPD followed by the CP%/CUSs for UVH and HADS-A score/age for CDA showed an overall diagnostic accuracy of 72.8%.Conclusions: Among the full vestibular tests and questionnaires, the items useful for differentiating chronic vestibular syndromes were identified. We proposed a diagnostic algorithm for chronic vestibular syndromes composed of these items, which could be useful in clinical settings.

Case Report: Isolated Idiopathic Saccular Dysfunction

Advances in vestibular testing have now allowed us to test each semicircular canal as well as the utricle and saccule, independently. This has led to the discovery of new patterns of vestibular dysfunction that were once impossible to evaluate. This report describes the case of a 20-year-old woman with a 2-month history of recurrent dizziness. She had a complete audiovestibular assessment. The only abnormality observed was the absence of a cervical vestibular-evoked myogenic potential response for the right side, hence an isolated saccular dysfunction. In conclusion, isolated otolithic dysfunction is probably an overlooked and neglected clinical presentation. Its true incidence is unknown, and further research is needed to understand this clinical entity.

Skull Vibration Induced Nystagmus Test: Correlations with Semicircular Canal and Otolith Asymmetries

Background: To establish in patients with peripheral vestibular disorders relations between skull vibration-induced nystagmus (SVIN) different components (horizontal, vertical, torsional) and the results of different structurally related vestibular tests. Methods: SVIN test, canal vestibular test (CVT: caloric test + video head impulse test: VHIT), otolithic vestibular test (OVT: ocular vestibular evoked myogenic potential oVEMP + cervical vestibular evoked myogenic potential cVEMP) performed on the same day in 52 patients with peripheral vestibular diseases (age < 65 years), and 11 control patients were analyzed. Mixed effects logistic regression analysis was performed to assert whether the presence of nystagmus in SVIN (3D analysis) have an association with the presence of peripheral vestibular dysfunction measured by vestibular explorations (CVT or OVT). Results: We obtained different groups: Group-Co (control group), Group-VNT (dizzy patients with no vestibular tests alterations), Group-O (OVT alterations only), Group-C (CVT alterations only), Group-M (mixed alterations). SVIN-SPV horizontal component was significantly higher in Group-M than in the other groups (p = 0.005) and correlated with alterations of lateral-VHIT (p < 0.001), caloric test (p = 0.002) and oVEMP (p = 0.006). SVIN-SPV vertical component was correlated with the anterior-VHIT and oVEMP alterations (p = 0.007; p = 0.017, respectively). SVIN-SPV torsional component was correlated with the anterior-VHIT positivity (p = 0.017). SVIN was the only positive test for 10% of patients (83% of Group-VNT). Conclusion: SVIN-SPV analysis in dizzy patients shows significant correlation to both CVT and OVT. SVIN horizontal component is mainly relevant to both vestibular tests exploring lateral canal and utricle responses. SVIN-SPV is significantly higher in patients with combined canal and otolith lesions. In some patients with dizziness, SVIN may be the only positive test.

Vestibular System Eletrophysiology: An Analysis of The Relationship between Hearing and Movement

Introduction Knowledge about the positive effects that music and dance bring, in its various forms, to the healthy human brain, is important not only in the context of basic neuroscience but may also strongly affect practices in neurorehabilitation. Objective To verify the relationship between hearing and movement and, specifically, to analyze the interference of professional dance practice and formal musical training in the magnitude of the vestibule-cervical and vestibular reflexes. Method The sample consisted of 92 subjects, aged between 18 and 35 years old, 31 professional musicians, 31 ballet dancers, and 30 control subjects. Only subjects with normal hearing sensitivity were included. Cervical vestibular evoked myogenic potential (cVEMP) was recorded in the sternocleidomastoid muscle, and ocular vestibular evoked myogenic potential (oVEMP) was recorded in the lower oblique muscle of the eye, using tone-bursts (500Hz). Analysis of variance (ANOVA) or Kruskall-Wallis tests were performed. Results The cVEMP presented earlier and higher amplitude waves when recorded in the group of dancers, with a significant difference between all tested groups for latency and amplitude of the N23 wave; the comparison was restricted between dancers and control groups, with no difference between ballet dancers and musicians. The N1 wave of the oVEMP presented lower latencies in dancers than in musicians and controls (p = 0.001). No significant differences were found between the groups for the P1 wave. Conclusion Greater magnitudes of vestibule-cervical reflex responses and faster vestibule-ocular reflex responses were observed in dancers. Dance practice provides greater development of the vestibular system, but musical training also contributes to the magnitude of these responses.

Comparison of Saccular Function in Nonmusicians and Violinists Using cVEMP: A Pilot Study

Introduction Human auditory and vestibular systems change due to noise exposure. Professional musicians are often subjected to loud music and longer durations as part of their practice. Although the effects of music have been explored extensively on the auditory system, it is important to understand changes in the vestibular system also. The current study is aimed to compare cervical vestibular evoked myogenic potential (cVEMP) findings in nonmusicians and violinists to understand if there are any changes in the P1 and N1 latencies and absolute amplitudes in the violinists’ groups because of their exposure to violin music. Materials and Methods Twelve participants (6 nonmusicians and 6 violinists) of both genders were included in the study. Pure tone audiometry and distortion product otoacoustic emissions (DPOAEs) were performed on all the participants. cVEMP P1 and N1 latencies and absolute amplitudes were obtained, and overall mean differences were compared within and between groups. Results Pure tone average and DPOAE were within the normal range between and within the groups. Results indicate that P1 and N1 absolute amplitudes and latencies were slightly prolonged in the violinists’ group; however, the mean difference was not statistically significant. Comparison of mean absolute amplitudes and latencies between the ears in the violinists’ group showed longer latencies and greater absolute amplitudes in the left ear of violinists as compared with the right ear. In the study, the violinists’ group consisted of participants who had an average daily exposure of about one-and-a-half hours and had an experience of playing the instrument for more than 5 years. Conclusion cVEMP is useful in detecting early changes in the saccule that may occur due to noise exposure. It can be concluded that, even before a clinically detectable hearing loss or vestibular damage, changes in saccule are observed with the help of cVEMP and should be included in the audiovestibular test for early identification.