Shigeto Itani

Intermittent positional downbeat nystagmus of cervical origin

Intermittent positional down beat nystagmus (p-DBN) is rare. We describe an unusual case of intermittent p-DBN which was induced by rotation, anteflexion, and lateral flexion of the neck. A 59-year-old man complained of loss of consciousness and lightheadedness. Positional testing revealed the p-DBN. The evoked p-DBN had latency and the patient had a feeling of passing out while the p-DBN was present. There were no abnormal findings in the vestibular functional examinations. Findings of the MRI were negative. MRA revealed no stenosis of the vertebral artery bilaterally, but there was an anatomical difference. The p-DBN characteristics were documented by electronystagmography during the positional test. The p-DBN lasted intermittently while maintaining the provoking position. It was found that p-DBN occurred with not only the rotation of the neck, but also in the anteflexion and lateral flexion of the neck. There was no stenosis of the vertebral artery (VA) on angiography, but we speculated that the cause of the p-DBN was the VA occlusion due to rotation, anteflexion, and lateral flexion of the neck.

Clinical evaluation of acute phase nystagmus associated with cerebellar lesions.

OBJECTIVES To determine the characteristics of acute phase nystagmus in patients with cerebellar lesions, and to identify a useful indicator for differentiating central lesions from peripheral lesions. METHODS Acute phase nystagmus and the appearance of neurological symptoms were retrospectively investigated in 11 patients with cerebellar stroke. RESULTS At the initial visit, there were no patients with vertical nystagmus, direction-changing gaze evoked nystagmus or pure rotatory nystagmus. There were four cases with no nystagmus and seven cases with horizontal nystagmus at the initial visit. There were no neurological symptoms, except for vertigo and hearing loss, in any cases at the initial visit. The direction and type of nystagmus changed with time, and neurological symptoms other than vertigo appeared subsequently to admission. CONCLUSION It is important to observe the changes in nystagmus and other neurological findings for the differential diagnosis of central lesions.

Spontaneous inversion of nystagmus without a positional change in the horizontal canal variant of benign paroxysmal positional vertigo.

OBJECTIVE We investigated the neuro-otological findings, including nystagmus, and the clinical course of patients with the horizontal canal variant of benign paroxysmal positional vertigo (HC-BPPV), who showed spontaneous inversion of nystagmus without a positional change. Furthermore, we speculated on the possible mechanism of spontaneous inversion of nystagmus without a positional change. PATIENTS AND METHODS The characteristics of spontaneous inversion of positional nystagmus without a positional change were analyzed in 7 patients with HC-BPPV. RESULTS All patients were diagnosed as having HC-BPPV. During the positional test, the spontaneous inversion of nystagmus was observed in the same head position in all patients. Spontaneous inversion was observed on both sides in 5 patients, and only on 1 side in 2 patients. All patients presented with geotropic nystagmus in the first phase, and ageotropic nystagmus in the second phase. CONCLUSIONS The coexistence of cupulolithiasis and canalolithiasis appears to be a possible mechanism of the spontaneous inversion of positional nystagmus.

Clinical study of tympanostomy tube placement for patients with intractable Ménière's disease

OBJECTIVE To evaluate the effectiveness of tympanostomy tube placement in controlling symptoms of intractable Menieres disease. METHODS Fifteen patients with intractable Menieres disease underwent tympanostomy tube placement in the affected ear. Post-operative changes in vertigo attacks and hearing level were recorded, and were evaluated according to American Academy of Otolaryngology-Head and Neck Surgery criteria. RESULTS At 12 months after treatment, 3 patients (20 per cent) showed complete control of vertigo, 7 (47 per cent) showed substantial control and 2 (13 per cent) showed limited control; 3 patients (20 per cent) required other treatment. At 24 months after treatment, 7 patients (47 per cent) showed complete control of vertigo, 3 (20 per cent) showed substantial control and 1 (7 per cent) showed limited control; 1 patient required other treatment 15 months after tympanostomy tube placement. CONCLUSION There is no definite pathophysiological explanation for the effect of tympanostomy tube placement in reducing vertigo attacks. This treatment is not effective for all patients with intractable Menieres disease. However, tympanostomy tube placement might be an additional surgical therapeutic option to consider prior to contemplating other, more invasive treatments.

Type 3 Thyroplasty for a Patient with Female-to-Male Gender Identity Disorder

Objective In most cases, about the voice of the patient with female-to-male/gender identity disorder (FTM/GID), hormone therapy makes the voice low-pitched. In success cases, there is no need for phonosurgery. However, hormone therapy is not effective in some cases. We perform type 3 thyroplasty in these cases. Method Hormone therapy was started in 2008 but did not lower the speaking fundamental frequencies (SFFs). We therefore performed TP3 under local anesthesia. Results In our case, the SFF at the first visit was 146 Hz. The postoperative SFF was 110 Hz. Conclusions TP3 was performed under local anesthesia in a patient with FTM/GID in whom hormone therapy proved ineffective. With successful conversion to a lower-pitched voice, the patient could begin to live daily life as a male. QOL improved significantly with TP3. If hormone therapy proves ineffective, TP3 may be selected as an optional treatment and appears to show few surgical complications and was, in this case, a very effective treatment.

Comparison of cervical vestibular evoked potentials evoked by air-conducted sound and bone-conducted vibration in vestibular Schwannoma patients

Abstract Objective: The vestibular evoked myogenic potential (VEMP) is associated with otolithic afferents and can be used to evaluate the function of the saccule and utricle. In this study, we compared cervical VEMP evoked by stimulation with Air-conducted sound (ACS) and bone-conducted vibration (BCV) to the forehead and investigated whether BCV can be used as a substitute for ACS. Methods: Data were obtained from 33 patients with vestibular schwannoma. Vestibular examinations were performed preoperatively. VEMP was obtained upon stimulation with ACS (ACS cVEMP) and BCV to the forehead using a minishaker (BCV cVEMP). Vestibular function was also analyzed using the caloric test and ocular VEMP (oVEMP) testing. oVEMP was measured using bone-conductive vibration to the forehead. The results of BCV cVEMP, ACS cVEMP, and oVEMP were compared by the caloric test. Results: Rates of patients with abnormal ACS cVEMP, BCV cVEMP, oVEMP, and caloric test results were 78.8%, 75.8%, 78.8%, and 69.7%, respectively. BCV cVEMP did not correlate with ACS cVEMP, but correlated with oVEMP and caloric test results. Conclusion: BCV cVEMP did not correlate with ACS cVEMP. Therefore, BCV cVEMP cannot be used as a substitute for ACS cVEMP.