Effects of diabetes mellitus type I with or without neuropathy on vestibular evoked myogenic potentials

Diabetes mellitus type I is a metabolic disorder that affects multiple systems including the inner ear. Patients with diabetes mellitus commonly complain about dizziness, floating sensation, tinnitus and sweating. The aim of this study was to compare vestibular evoked myogenic potentials [VEMPs] between diabetic patients with or without neuropathy. Subjects included 14 patients with diabetes mellitus type I with polyneuropathy, 10 patients with diabetes mellitus type I without polyneuropathy and 24 healthy volunteers. Range of age in participants was 15-40 years old. The VEMPs were recorded with 500 Hz tone bursts with intensity at 95 dB. There was statistically significant difference between the groups in P13 and N23 latencies [P<0.05]. There was no statistically significant difference between groups in absolute and relative amplitudes. Prolonged latencies of the VEMP suggest lesions in the retrolabyrinthine, especially in the vestibulospinal tract

Spontaneous nystagmus in benign paroxysmal positional vertigoþ:þ is it a new sign?

Benign Paroxysmal Positional Vertigo [BPPV] is a condition that indicates a benign inner ear disorder. It is generally believed that BPPV is due to the dislodged otoconial particles from otolith organs and unusual collection of them within any of semicircular canals or even in all three semicircular canals. Although the typical features of nystagmus in BPPV have been well-studied, very few studies [just four articles] have highlighted the presence of spontaneous nystagmus in BPPV recently. During the past 10 years, 2850 patients have been examined at the audiology unit of our department, and 254 patients have received diagnoses of BPPV but recently 2 patients presented with BPPV and spontaneous nystagmus, a new symptom that has been never observed in our clinical records. We herein describe this rare symptom in 2 case of BPPV. A 50-year-old woman with BPPV who showed an 18 degree spontaneous nystagmus treated with Epley maneuver and a 53-year-old man with 3 degree spontaneous nystagmus

[Smooth pursuit in migraine patients]

Neurotologic signs and symptoms, especially vestibular symptoms, are common in migraine patients. The goal of this study was to investigate some parts of the central vestibular system using some subtests of videonystagmographic evaluation, including spontaneous nystagmus, gaze-evoked nystagmus, and smooth pursuit between their attacks of migraine. Thirty patients with migraine and 38 healthy volunteers of 18-48 years of age were included in this study. Spontaneous nystagmus, gaze-evoked nystagmus toward the right, left and upward, and also smooth pursuit using three different velocities were performed in both groups. Five normal subjects and five migraine patients had spontaneous nystagmus, which was less than three degrees; there was no statistically significant difference between the two groups. No gazeevoked nystagmus was seen in both groups. In one velocity of smooth pursuit evaluation, gain and phase were significantly different. The statistical difference in gain and phase was not clinically important as it was in normal range of the device. Another statistically significant parameter was saccadic morphology of smooth pursuit which was seen in migraine patients. These results suggest the presence of subtle otoneurological abnormalities in migraine patients that is probably due to deficiency of oculomotor function with vestibulocerebellar origin

[Effect of prophylactic drugs on vestibular evoked myogenic potential in migraine patients]

In many migraine patients prophylactic drugs are effective in reducing attacks and symptoms such as vestibular complaints. Therefore, related neural pathways are probably also affected. This study aimed to compare vestibular evoked myogenic potential in migraine patients under treatment with prophylactic drugs and those without any treatment. Subjects included 46 patients with migraine. They were evaluated in two groups; those under treatment with prophylactic drugs [21 subjects] and those without treatment [25 subjects]. The age range of patients was 20-60 years. The vestibular evoked myogenic potential were recorded with 500 Hz tone bursts at 95 dB nHL. Mean of amplitude ratio [p=0.02], and interpeak latency values in the right ear [p=0.03] and left ear [p=0.001] were higher in patients with prophylactic therapy than the group without therapy; this difference was statistically significant. There was no statistical difference between the two groups in terms of mean of latency of p13 and n23 peaks, and absolute amplitude [p>0.05]. Prophylactic drugs probably improve mean of main response parameters of vestibular evoked myogenic potential in migraine patients with prophylactic therapy

[Vestibular evoked myogenic potentials in migraine patients]

Patients with migraine commonly show vestibular symptoms. However, abnormal neurotological test findings during the inter-attack intervals, even in the absence of vestibular symptoms, are suggestive of subclinical vestibular dysfunction in migraine. This study aimed to compare the vestibular evoked myogenic potentials between migraine patients and normal individuals. Subjects included 25 patients with migraine and 26 healthy volunteers with an age range of 20-53 years old. The vestibular evoked myogenic potentials were recorded with 500 Hz tone bursts at 95 dB nHL. Mean of absolute amplitude and p13 latency values in the migraine group were significantly less and more than the normal group, respectively [p=0.001 for absolute amplitude in right ant left ears; p=0.004 for p 13 latency in right ears and p=0.02 in left ears]. There was no statistically significant difference between the two groups in mean of the n23 latency and also the amplitude ratio [p>0.05]. According to the prolonged latency of vestibular evoked myogenic potentials response, vestibulospinal tract in brainstem is probably involved in migraine patients. However, due to small sample size, for generalizing this result to all patients with migraine, further researches are needed

[Investigation of Persian speech interaural attenuation in adults]

As clinical audiometry assessment of each ear needs to know interaural attenutation [IA], the aim of this study was to investigate Persian speech IA in adults. This cross-sectional, analytic study was performed on 50 normal hearing students [25 males, 25 females], aged 18-25 years old in Faculty of Rehabilitation, Tehran University of Medical Sciences. Speech reception threshold [SRT] was determined with descending method with and without noise. Then speech IA for Persian spondaic words was calculated with TDH-39 earphones. Mean speech IA was 53.06 +/- 3.25 dB. There was no significant difference between mean IA in males [53.88 +/- 2.93 dB] and females [52.24 +/- 3.40 dB] [p>0.05]. The lowest IA was in females [45dB] and the highest IA was in males [60 dB]. Mother's language has no significant effect on speech IA. We may consider 45 dB as the lowest IA for Persian speech assessment, however generalization needs more study on a larger samples