Biomedical subjects

Måns Magnusson

Publications and source records attributed to Måns Magnusson.

3 recordsLinked to original sources

PubMed2003

Phobic postural vertigo: body sway during vibratory proprioceptive stimulation.

Phobic postural vertigo patients might rely more on proprioceptive than visual cues to regulate stance. We tested 14 phobic postural vertigo patients and 24 healthy subjects with posturography during quiet stance and periods of vibratory proprioceptive calf muscle stimulation, both with eyes open and closed. During quiet stance phobic postural vertigo patients showed higher torque variance than healthy subjects, especially above 0.1 Hz. Vibratory proprioceptive stimulation increased the differences between healthy subjects and phobic postural vertigo patients. The patients were less able to use vision to counteract vibration-induced movements. Phobic postural vertigo patients are more sensitive to proprioceptive disturbances than healthy subjects are, and less apt to use visual information to control upright stance. This might be part of an anxious mode of balance control.

Adult↗

PubMed2002

Visual influence on postural control, with and without visual motion feedback.

Body sway was investigated in 20 healthy subjects to determine whether visual input must contain motion feedback information from the surroundings in order to influence postural control. Posturography was used to record body sway under the following visual conditions: eyes open with or without a restricted visual field; eyes open in ganzfield white light; eyes open in darkness with a head-fixed visual target; eyes open in darkness; and eyes closed in darkness. Stance was perturbed by means of a pseudorandomly applied vibratory stimulation to the calf muscles. Least sway was found with eyes open in an unrestricted visual field but increased in a restricted visual field. Greatest sway was found without visual motion feedback, i.e. under the following conditions: eyes closed; eyes open in darkness; eyes open in ganzfield white light; and with a head-mounted fixation point. Sway was significantly (p < 0.05) greater with eyes open in darkness compared with eyes closed during the initial 50 s with perturbations. After 150 s, sway was almost identical under the four test conditions without visual motion feedback. Standing with eyes open in darkness was initially a disadvantage compared with having the eyes closed. The postural control system may be programmed to expect visual feedback information when the eyes are open, which may delay changes in postural strategy.

Adaptation, Physiological↗

PubMed2002

Peripheral vestibular disorders with acute onset of vertigo.

Disorders of the vestibular nerve and end organs are the most common causes of vertigo. The advances in recognizing different forms of canalolithiasis and cupulolithiasis, which sometimes present with continuous positional nystagmus, have revealed a peripheral vestibular aetiology in which central nervous system lesions were previously suspected. Treatments using repositioning manoeuvres are also successful in cases in which nystagmus does not appear, and when administered by less specialized physicians. In acute vestibulopathy, suspicions of the activation of herpes virus infections as a causative agent are increasing, but no reports on the treatment of such infections are yet available. New treatments are in development for use in Ménière's disease.

Acute Disease↗