Mahito Ito

Natural History of Benign Paroxysmal Positional Vertigo and Efficacy of Epley and Lempert Maneuvers

We assessed the efficacy of Epley maneuver in patients with posterior canal benign paroxysmal positional vertigo (P-BPPV) and Lempert maneuver in patients with horizontal canal BPPV (H-BPPV). In patients with P-BPPV, positional vertigo in patients treated by Epley maneuver was significantly resolved more quickly than that in untreated patients. But in patients with H-BPPV, there were no significant differences of time course in remission of positional vertigo between untreated patients and patients treated by Lempert maneuver. Among the untreated patients, the positional vertigo in patients with H-BPPV was significantly resolved more quickly than that in patients with P-BPPV. Epley maneuver was effective for the treatment of patients with P-BPPV, whereas the efficacy of Lempert maneuver for the treatment of patients with H-BPPV was limited. The natural courses in remission of positional vertigo in untreated patients with H-BPPV showed significantly faster resolution than that in patients with P-BPPV.

3D analysis of benign positional nystagmus due to cupulolithiasis in posterior semicircular canal.

Conclusions: The characteristic of both the vertical-torsional positional nystagmus with long time constant and its disappearance at the neutral head position could diagnose cupulolithiasis in posterior semicircular canal (PSCC) in the eight patients with the PSCC type of benign paroxysmal positional vertigo (P-BPPV). Objective: The aim of the study was to diagnose cupulolithiasis in patients with P-BPPV. Patients and methods: We used three-dimensional rotation axis analysis of nystagmus of the vertical-torsional positional nystagmus in 111 patients with P-BPPV and evaluated its time constant. We then examined whether the vertical-torsional positional nystagmus with long time constant disappeared at the neutral head position where the axis of the heavy cupula of the affected PSCC is aligned with gravity. Results: The first parameter showed a wide variation that could be divided into two groups: one lasting more than 40 s in 8 patients and another below 20 s in 103 patients. Since the time constant of the positional nystagmus induced by cupulolithiasis was much longer than that induced by canalolithiasis, this finding suggests that cupulolithiasis in the PSCC induced the vertical-torsional positional nystagmus with a long time constant in the group of eight patients. The vertical-torsional positional nystagmus disappeared in these patients at the neutral head position, where the axis of the cupula of affected PSCC aligned with gravity.

Natural course of positional vertigo in patients with apogeotropic variant of horizontal canal benign paroxysmal positional vertigo

OBJECTIVE The purpose of this study was to assess the natural course of positional vertigo in patients with the apogeotropic variant of horizontal canal type of benign paroxysmal positional vertigo (AH-BPPV), which is reported to be more refractory to physiotherapy than the geotropic variant of horizontal canal type of BPPV (GH-BPPV). METHODS 14 patients with AH-BPPV treated without physiotherapy were asked to visit the hospital every 2 weeks. At every follow-up visit, they were interviewed and positional nystagmus was assessed. After the disappearance of positional nystagmus, patients were asked about the time of cessation of the positional vertigo. Thus, the primary outcomes were evaluated by the self-reported onset and remission of positional vertigo. The time course of remission of positional vertigo was then calculated. RESULTS The average and median period from the onset to natural remission of positional vertigo in patients with AH-BPPV was 13 and 7 days, respectively. CONCLUSION We have already reported that the average and median period from the onset to natural remission of positional vertigo in patients with GH-BPPV was 16 and 7 days, respectively (Imai et al., 2005 [8]). Thus, the natural course of AH-BPPV is not as refractory as that of GH-BPPV.

Changes in slow phase eye velocity and time constant of positional nystagmus at transform from cupulolithiasis to canalolithiasis

Changes in slow phase eye velocity (SPEV) and time constant (TC) of benign paroxysmal positional nystagmus in horizontal canal type were examined at transitional period from cupulolithiasis (apogeotropic nystagmus) into canalolithiasis (geotropic nystagmus) in two patients. SPEV and TC of positional nystagmus were tri-dimensionally analyzed. The first patient showed an apogeotropic nystagmus. Head rotation to the left in supine position induced a right-beating nystagmus with an initial SPEV of 15.3°/s and a TC of 133 s. The nystagmus then gradually declined with a TC of 31.3 s after reaching a maximum SPEV of 28.8°/s. After the nystagmus disappeared, he showed a geotropic nystagmus. The second patient showed a left-beating nystagmus with an initial SPEV of 2.5°/s and a TC of 141 s when his head was rotated to the right in supine position. The nystagmus then gradually declined with a TC of 8.05 s after reaching a maximum SPEV of 16.7°/s. After the nystagmus disappeared, he showed a geotropic nystagmus. The present findings suggested that in both patients, at the period of an increase of SPEV of the positional nystagmus with the shortening of its TC, cupulolithiasis transformed into canalolithiasis.

Three-dimensional Analysis of Benign Paroxysmal Positional Nystagmus in a Patient with Anterior Semicircular Canal Variant

Objective: To show the positional nystagmus in a patient who had suffered from benign paroxysmal positional vertigo (BPPV) that was thought to be caused by involvement of the anterior semicircular canal (ASCC) (A-BPPV). Study Design: Retrospective case report. Setting: City hospital. Patient: The present study reports a rare case of A-BPPV in a 41-year-old woman. Case Report: The patient is 41-year-old woman who developed a positional vertigo after playing volleyball on March 22, 2005 and consulted our hospital the next day. When left Dix-Hallpike maneuver was performed, she showed a positional nystagmus of which fast phase direction of the torsional component was clockwise while that of the vertical component was downward. We plotted the slow phase eye velocity of the positional nystagmus during the left Dix-Hallpike maneuver on three-dimensional coordinates that showed the axis of the positional nystagmus to be perpendicular to the plane of the right ASCC. Conclusion: These results suggested that the patient was suffering from A-BPPV.

Differential diagnosis of true and pseudo-bilateral benign positional nystagmus

Conclusions. Two patients showing two rotational axes of their positional nystagmus had canalolithiasis in bilateral posterior semicircular canals (PSCCs), leading to the diagnosis of true bilateral benign paroxysmal positional nystagmus (P-BPPN). Another 18 patients had a single rotation axis of their positional nystagmus with short time constant (TC) on one side and long TC on the other. Since canalolithiasis in the uppermost PSCC may be transient cupulolithiasis, evoking positional nystagmus with long TC, the diagnosis of the latter patients should be pseudo-bilateral P-BPPN. Objective. To differentiate the true bilateral posterior canal type of P-BPPN from pseudo-bilateral P-BPPN. Patients and methods. The rotational axis and TC of positional nystagmus were three-dimensionally analyzed in 20 patients showing geotropic torsional nystagmus on the left and right Dix-Hallpike (D-H) maneuvers. Results. Two patients showed two rotational axes of their positional nystagmus, which were perpendicular to the plane of the PSCCs. There were no differences in TCs of their positional nystagmus between bilateral D-Hs. Another 18 patients showed a single rotational axis of their positional nystagmus, which was perpendicular to the plane of either the left or right PSCC. TCs of their positional nystagmus were short on one side and long on the other.

Benign Paroxysmal Positional Vertigo due to a Simultaneous Involvement of both Horizontal and Posterior Semicircular Canals

From April 2001 to November 2003, we investigated 8 patients with benign paroxysmal positional vertigo (BPPV) that was suspected to simultaneously affect both the horizontal and posterior semicircular canals (HSCC and PSCC). These cases showed typical vertical-torsional nystagmus induced by the Dix-Hallpike maneuver, followed by a horizontal nystagmus. They also showed a direction-changing geotropic or apogeotropic positional nystagmus triggered by lateral head rotations in the supine position. Using the three-dimensional analysis of the positional nystagmus, the rotation axis of the positional nystagmus had a component perpendicular to the plane of PSCC and another component perpendicular to the plane of HSCC. All these findings suggest that BPPV in these patients was a combination of posterior and horizontal canal BPPV. The observation of a vertical-torsional positional nystagmus should prompt the specialist to perform not only the canalith repositioning procedure, but also to execute lateral head turns in the supine position.

Blood and tissue concentrations of Latamoxef.

The concentration of Latamoxef (LMOX) was determined by bioassay in surgical patients with sinusitis and chronic tonsillitis. One or two grams of LMOX was injected intravenously prior to tonsillectomy under general anesthesia and the Caldwell-Luc operation under local anesthesia.Concentrations of LMOX in the tonsil and maxillary bone were 12.7μg/g and 16.8μg/g respectively one hour after administration;and 9.4μg/g and 2.3μg/g respectively two hours after administration.The transfer ratio, the concentration in the tonsil to that in the serum, was about 20 percent. The tissue concentrations exceeded the antibacterial level of LMOX except for Pseudomonas aeruginosa.