title: Effects of lactate-induced panic attacks on brain stem auditory evoked potentials.
abstract: As the clinical symptomatology of panic attacks may be conceivably related to abnormal brain stem activity, the present study examined the effect of lactate-precipitated panic on brain stem auditory evoked potentials (BSAEPs). The subjects were 27 patients who met DSM-III criteria for panic disorder (Pd), agoraphobia with panic attacks (AgPa) or agoraphobia (Ag). Following drug washout, patients were tested in two separate sessions, in a double-blind randomised controlled design in which each session involved two sequentially ordered BSAEP collection periods - a baseline period with no infusion followed by an intravenous infusion of 5% dextrose in water or 1.0 M sodium lactate (5 ml/kg in 5% dextrose/water) over a 20-min period. Of the 27 patients, 17 were clear responders, reporting panic attacks and self-report changes under lactate similar to those occurring during spontaneous panic. Of the remaining 10 patients, 6 were pseudo-responders, reporting panic symptoms under both dextrose and lactate, and 4 were non-responders. In the clear responders, lactate did not alter electrical events of the BSAEP, but further analysis within the clear responders, comparing AgPa patients with Pd patients, yielded a significant effect with lactate resulting in a prolonged III-V inter-peak interval in the AgPa group. It is suggested that the increased III-V interval in the AgPa group may be reflective of hyperactivity of brain stem noradrenergic nuclei.
mesh_terms: D001007:Anxiety / Q000523:psychology; D001831:Body Temperature; D001933:Brain Stem / Q000502:physiology*; D005072:Evoked Potentials, Auditory / Q000187:drug effects*; D005239:Fear / Q000502:physiology*; D005260:Female; D006801:Humans; D007773:Lactates / Q000494:pharmacology*; D019344:Lactic Acid; D008297:Male; D009055:Mouth; D010200:Panic / Q000502:physiology*; D011930:Reaction Time
chemical_list: D007773:Lactates; D019344:Lactic Acid