Articles: vertigo.
-
Acta oto-laryngologica · Mar 1996
Receptorpharmacological models for the therapy of labyrinthine vertigo.
In the mammalian labyrinth, GABAA receptor subtypes are involved in the excitatory neurotransmission between the vestibular type II hair cells and the afferent neurons. Additional afferent ionophoric receptor channels, sensitive to further transmitter candidates, are discussed for both types I and II hair cells. GABA accelerates excitotoxic cell death in cortical neurons. ⋯ Moderate allosteric blockers of the GABAA receptor channel and weak inverse agonists of the benzodiazepine binding site meet some requirements for potentially successful clinical application. The suppressing action of the suitable drugs picrotoxin and flumazenil on labyrinthine nystagmus and vertigo, tested in clinical trials, supports the hypothesis that GABAA receptors are involved in vestibular neurotransmission, even in humans. The test results promise the development of a successful vestibular receptorpharmacology in the near future.
-
Few papers describe illusions of motion after sailing for which subjects do not seek medical assistance. After sailing on a square-rigged ship for five-hour periods subjects were surveyed about the incidence, intensity, and quality of such illusions. ⋯ This phenomenon is characterized by extinction with repeated exposure, a lag time to onset of about two hours, brief duration, and occurrence in enclosed visual surrounds. These data are similar to vestibular habituation and suggest that some central vestibular mechanisms may be involved.
-
Dizziness is a common and vexing diagnostic problem in emergency departments. The term is rather undefinite and often misused, but can in practice be classified into four categories: fainting, disequilibrium, vertigo and miscellaneous syndromes. Vertigo is the most common category of dizziness. ⋯ Physicians working in emergency departments must be able to rapidly identify patients with potentially serious forms of vertigo, which could cause death or disability, and patients with mild conditions, that can be effectively treated. Previous studies and the experience of the authors have shown that reliable diagnostic hypotheses can be generated by taking a proper clinical history (focused on the onset and duration of the disease, the circumstances causing the vertigo and associated otological or neurological symptoms) and performing an accurate physical examination (evaluation of neurological defects and spontaneous or provoked nystagmus), supplemented by few laboratory tests and diagnostic procedures. Therapy of vertigo in emergency settings is mainly symptomatic and based on sedation and use of vestibulosuppressant drugs (antihistamines, phenothiazines).
-
The symptom of vertigo can be due to many different causes. Differential diagnosis will be discussed primarily from a neuro-otologic point of view. Vertigo can be thought of as a subjective disturbance of the integration of different sensory inputs. ⋯ Instability and nystagmus towards a specific direction point to a vestibular disorder, especially if the nystagmus is suppressed by optical fixation. The most common causes of a vestibular disorder are benign paroxysmal positional vertigo (BPPV), a sudden vestibular loss (or vestibular neuritis), and Ménière's disease. These three diseases are discussed briefly.
-
Otolaryngol Head Neck Surg · Jun 1995
Randomized Controlled Trial Clinical TrialMastoid oscillation: a critical factor for success in canalith repositioning procedure.
The canalith repositioning procedure has recently gained controversial recognition as a treatment for benign paroxysmal positional vertigo. Some authors contend that the canalith repositioning maneuver is no more effective than no treatment at all. Unfortunately, its technique has not been uniformly applied and its outcomes have not been uniformly assessed. ⋯ An overwhelming 92% of those who received the canalith repositioning maneuver with mastoid vibration felt improved, and 70% were free of rotatory nystagmus after only one treatment. A review of all patients diagnosed with benign paroxysmal positional vertigo and treated with the canalith repositioning maneuver with mastoid vibration was also undertaken. In a series of 67 patients with a minimum of four weeks of follow-up, only two have not responded to the canalith repositioning maneuver, yielding a 97% rate of symptom control.