Effects of brainstem lesions on amino acid levels in the rat cochlear nucleus.

There is evidence for glutamate, γ-amino butyric acid (GABA), and glycine as neurotransmitters of centrifugal pathways to the cochlear nucleus, but the quantitative extent of their contributions to amino acid neurotransmission in cochlear nucleus regions has not been known. We used microdissection of freeze-dried tissue sections of rat cochlear nucleus, with mapping of sample locations, combined with a high performance liquid chromatography (HPLC) assay, to measure amino acid levels in cochlear nucleus subregions of rats with unilateral lesions of centrifugal pathways to the cochlear nucleus. In rats with lesions transecting all or almost all pathways to the cochlear nucleus from brain stem regions, GABA, aspartate, and glutamate levels were reduced, compared to contralateral values, in almost all ipsilateral cochlear nucleus regions.

Nystagmus during attacks of vestibular migraine: an aid in diagnosis.

Introduction: An estimated one-fourth to one-third of patients with migraine will experience vertigo associated with their migraine attacks. Vestibular migraine frequently presents as a diagnostic challenge as objective neurological findings consistent with this entity have not been well described.

Objective: The aim of this study is to characterize eye movements of patients presenting with nystagmus during attacks of migrainous vertigo.

Unnecessary diagnostic tests often obtained for benign paroxysmal positional vertigo.

Background: Benign paroxysmal positional vertigo (BPPV) is a common cause of vertigo prompting patients to seek medical treatment. Diagnosis is made by identifying characteristic nystagmus with positional testing (e.g.

Screening for vestibular disorders: a study of clinicians' compliance with recommended practices.

Background: Dizziness and vertigo are very common patient complaints encountered by clinicians in both primary as well as specialty care in otolaryngology and neurology. Vestibular impairment is an underlying cause in as many as 45% of people complaining of dizziness. Most causes of vestibular impairment can be effectively treated; however, the diagnosis is frequently missed.

Diffusion tensor and functional magnetic resonance imaging of diffuse axonal injury and resulting language impairment.

Diffuse axonal injury (DAI) is a common aftermath of brain trauma. The diagnosis of DAI is often difficult using conventional magnetic resonance imaging (MRI). We report a diffusion tensor imaging (DTI) study of a patient who sustained DAI presenting with language impairment.