Evaluation of Saccule Function in Patients with Vitamin D Deficiency

BACKGROUND AND OBJECTIVES: Considering important role of vitamin D in many physiological processes including vestibular system in the ear, aim of present study is to evaluate saccule function via cervical vestibular evoked myogenic potential (cVEMP), in patients with vitamin D deficiency. SUBJECTS AND METHODS: After routine audiological tests, cVEMP were recorded in 15 patients with vitamin D deficiency and 16 normal subjects. The short tone burst (95 dB nHL, 500 Hz) was presented to ears. cVEMP was recorded with surface electromyography over the contracted ipsilateral sternocleidomastoid muscle. RESULTS: Mean of p13, n13, interpeak latencies and amplitude ratios were measured in both groups. Statistical analysis did not show differences between two groups. CONCLUSIONS: Maybe serum 25-hydroxyvitamin D concentration was not low enough to have effect on saccule in the patients in present study or saccule have had low susceptibility to effects of vitamin D deficiency. For better judgment about effect of vitamin D deficiency on saccular function planning studies with high sample size is recommended.

[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