Head-tilting stabilometry in patients with benign paroxysmal positional vertigo.

OBJECTIVE: One of the pathologic conditions underlying benign paroxysmal positional vertigo (BPPV) is degeneration of the otolith organs. In this study, we examined changes in the parameters of stabilometry under an upright condition and head-tilt conditions in patients with BPPV. METHODS: We performed stabilometry on 21 patients with right BPPV, on 21 patients with left BPPV and on 21 controls. First, the subject stood barefoot in an upright position with both feet together on the platform with eyes closed. Next, tilting of the head about 30 degrees to the left was added. Then, tilting about 30 degrees to the right was performed. RESULTS: In right BPPV patients, the total length of velocity vectors in the right or left direction on right or left head-tilt were significantly smaller than those in an upright position. The enveloped area and total length of velocity vectors in the right or left direction were significantly larger than those in controls. In left BPPV patients, there were no parameters that showed any significant difference. CONCLUSIONS: In this study, lesions of right BPPV patients were coincidentally more severe than those in left BPPV patients, and velocity vectors with head-tilts were significantly smaller than in an upright position. Using the total length of the velocity vectors, head-tilting stabilometry has the potential to become a reliable otolith function examination method.

Investigation into dizziness before and after Epley's maneuver for benign paroxysmal positional vertigo using stabilometry.

OBJECTIVE: To investigate the cause of dizziness after Epley's maneuver using stabilometry. METHODS: Subjects were 35 patients with posterior canal type BPPV. First we performed stabilometry, next Epley's maneuver, then stabilometry was performed again. The enveloped area and the locus length per second of stabilometry were compared. RESULTS: Seventeen patients reported a feeling of dizziness after the treatment, whereas the other 18 patients did not. The patients were divided into two groups: 17 patients with dizziness (WD) and 18 patients without dizziness (WOD) after the treatment. In the WD group, the enveloped area (P=0.0495) and the locus length per second (P=0.0099) before Epley's maneuver were significantly lower than those after Epley's maneuver. In the WOD group, there was no significant difference in the stabilometry parameter between values obtained before and after Epley's maneuver. There were no significant differences found in either parameter between these two groups either before or after applying Epley's maneuver. CONCLUSIONS: Epley's maneuver is a treatment for the posterior semicircular canal. Malfunction of the otolith organ remains. It is considered that the cause of dizziness after Epley's maneuver comes from otolith dysfunction.

Comparison between stabilometry with and without head tilts in a roll plane.

OBJECTIVE: We examined the influence of head-tilting on stabilometry, which is similar to positional nystagmus in a sitting position. METHODS: The subjects were 35 healthy individuals and 11 patients with unilateral vestibular disorder. We compared parameters measured in an upright position and those with left head-tilt or right head-tilt. We used Wilcoxon's signed ranks test for statistical analysis. RESULTS: In the group of healthy adults, the Enveloped area with left head-tilt and right head-tilt increased significantly compared to that in the upright position (P=0.0111). The parameters that decreased significantly were Locus length per unit area (P=0.0007). The center of gravity on the Y-axis shifted backward significantly (P<0.0001). In the group of unilateral vestibular disorder, there were no parameters that showed significant difference CONCLUSION: One could argue that a combination of displacement of the body itself, influence of proprioceptive sensation, and influence of otolith affects the output of stabilometry. It would be possible to develop this test if the first and the second are excluded.

[Neurotological long-term follow-up in Minamata disease in Niigata, Japan].

To determine the long-term influence of organic mercurial intoxication on audiological and equilibrium findings, we followed up 36 patients neurotologically during 1980-1987 and 1991-2000 at Kido Hospital in Niigata. Typical findings were as follows: 1. In pure-tone audiometry, 24 of 72 ears (33%) showed slight hearing deterioration and 3 (4%) showed improvement. 2. Spontaneous nystagmus had disappeared in 5 patients (14%), but appeared in new 13 patients (36%). Positional nystagmus did not improve in any patient, and deteriorated in 11 (31%). 3. In optokinetic nystagmus (OKN) tests, especially in vertical OKN test showing significant deterioration (44%). 4. The caloric nystagmus test showed marked deterioration (47%). Body-equilibrium testing showed slight deterioration in 11 patients (31%) and improvement in 5 (14%). Neurotological findings thus varied widely among patients and we were concluded that these differences were caused both by duration of methyl mercury contamination and by aging factors in patients.