We report a unique case of vertebrobasilar transient ischemic attacks manifesting as isolated, recurrent, orthostatic dizziness with posterior inferior cerebellar artery (PICA) stenosis. A 57-year-old male patient without past medical history, presented with brief orthostatic dizziness for 2 weeks. There was no associated nausea, vomiting, diplopia, or weakness. On neuro-otologic examination, the patient did not show spontaneous, positional, or gaze-evoked nystagmus. Vestibular function tests such as caloric test, head impulse test, video-oculography, and tilt table test were normal. Brain diffusion-weighted images showed multiple small high signal intensities in the bilateral cerebellar hemispheres. Brain magnetic resonance angiography revealed hypoplasia of the right vertebral artery without focal intracranial focal stenosis. Four-vessel cerebral angiogram showed severe stenosis at the right PICA artery. Our patient’s clinical scenario appears unique hemodynamic spells without symptoms or signs of posterior circulation ischemia. Physicians should also consider cerebrovascular ischemic when the patient suffers repeated orthostatic dizziness that is not explained clinically.
Sudden sensorineural hearing loss (SNHL) develops usually in unilateral ear
without known etiology. In contrast, bilateral sudden SNHL is mostly related to
serious systemic diseases and have a severe hearing loss and poor prognosis
compared than unilateral one. We describe here a 59-year-old man presented with
a bilateral sudden SNHL and vertigo possibly attributed to dolichoectasia in
vertebrobasilar artery, and discuss the possible mechanism.
Background and Objectives: The present study investigated the role of the peripheral vestibular end organ in vestibular symptoms and temporal changes in expression of c-Fos protein in the vestibular nuclei following anterior inferior cerebellar artery (AICA) occlusion using rats with unilateral or bilateral labyrinthectomy.
Materials and Methods: Expression of c-Fos protein in the vestibular nuclei was measured 2, 12, 24, and 48 hours after AICA occlusion.
Results: Unilateral AICA occlusion significantly induced expression of c-Fos protein bilaterally in the medial, inferior, superior, and lateral vestibular nuclei. Following AICA occlusion, the medial vestibular nucleus (MVN) showed the highest expression of c-Fos protein among the 4 vestibular nuclei. The expression of c-Fos protein was asymmetric between the bilateral MVN, showing higher expression in the MVN contralateral to the side of AICA occlusion compared to the ipsilateral MVN. The degree of asymmetry in c-Fos protein expression between the bilateral MVN peaked 12 hours after AICA occlusion. The expression of c-Fos protein gradually decreased 24 hours after AICA occlusion and returned to control levels 48 hours after AICA occlusion. Unilateral labyrinthectomy significantly decreased expression of c-Fos protein in the MVN ipsilateral to the side of labyrinthectomy following AICA occlusion. Moreover, bilateral labyrinthectomy significantly decreased expression of c-Fos protein in the bilateral MVN flowing AICA occlusion.
Conclusion: These results suggest that afferent signals from the peripheral vestibular end organ are crucial to the expression of c-Fos protein in the MVN following AICA occlusion and that expression of c-Fos protein is sustained for 24 hours after AICA occlusion.
The nystagmus of vertebrobasilar insufficiency (VBI) patients is not clearly understood. In this article we report a videonystagmography (VNG) result which had been recorded in a VBI patient during his ictal period. The spontaneous nystagmus was purely torsional toward the left side. During the various positional tests, up beating left torsional and right horizontal nystagmus was found. Right beating horizontal nystagmus was stronger when the head was turned to the left side. But we were not able to explain the exact mechanism of this nystagmus. Although the mechanism is not fully understood the pattern of nystagmus reported in this article may be helpful in distinguishing VBI from other diseases by means of VNG recording.