P50 sensory gating in panic disorder.

Previous studies with prepulse inhibition in panic disorder (PD) have suggested that the early stages of sensory information processing are abnormal in patients with PD. To further investigate sensory gating function in panic disorder we performed a case-control study in a sample of 28 patients with PD, compared to 28 normal subjects and 28 schizophrenic subjects evaluating auditory mid-latency evoked potential P50 in a double-click paradigm as a measure of sensory gating. PD subjects showed weaker sensory gating as evidenced by higher P50 ratios as compared to normal subjects (62.

Impaired P50 sensory gating in Machado-Joseph disease.

Objective: Machado-Joseph disease (MJD), an autosomal dominant spinocerebellar degeneration caused by an expanded CAG repeat on chromosome 14q32.1, is a disorder with wide range of neurological findings and brain regions involved. Studies evaluating neurophysiological parameters related to sensory gating in MJD are lacking.

The adenosine antagonist theophylline impairs p50 auditory sensory gating in normal subjects.

In the p50 suppression paradigm, when two auditory stimuli are presented 500 ms apart, the amplitude of the second response (S2), compared with the first (S1), is markedly attenuated in healthy subjects. This is an index of sensory gating. Most schizophrenic patients fail to inhibit the p50 response to the second stimulus, which is assumed to reflect an inhibitory deficit.