Effects of lactate-induced panic attacks on brain stem auditory evoked potentials

Area of Science:

• Neuroscience
• Psychiatry
• Clinical Psychology

Background:

• Panic attacks may stem from abnormal brain stem activity.
• Brain stem auditory evoked potentials (BSAEPs) can assess neural function.

Purpose of the Study:

• To investigate the effect of lactate-induced panic on BSAEPs in patients with panic disorder.
• To explore potential differences in brain stem activity between panic disorder subtypes.

Main Methods:

• 27 patients with panic disorder, agoraphobia with panic attacks, or agoraphobia underwent a double-blind, randomized controlled trial.
• BSAEPs were recorded at baseline and after intravenous infusion of sodium lactate or dextrose.
• Patients were categorized as clear responders, pseudo-responders, or non-responders based on panic symptoms.

Main Results:

• Lactate did not alter BSAEPs in clear responders overall.
• A subgroup analysis of clear responders revealed a significantly prolonged III-V inter-peak interval in agoraphobia with panic attacks patients compared to panic disorder patients.
• No significant BSAEP changes were observed in pseudo-responders or non-responders.

Conclusions:

• The prolonged III-V interval in agoraphobia with panic attacks patients may indicate hyperactivity in brain stem noradrenergic nuclei.
• This finding suggests distinct neurophysiological mechanisms underlying different panic disorder presentations.
• BSAEPs may serve as a biomarker for specific panic disorder subtypes.