Brain-stem auditory-evoked potentials during lidocaine infusion in humans

Area of Science:

• Neuroscience
• Audiology
• Pharmacology

Background:

• Lidocaine is commonly used for anesthesia and cardiac therapy.
• Systemic lidocaine levels can affect central nervous system functions.
• Auditory brain-stem responses (ABR) are sensitive indicators of neural pathway integrity.

Purpose of the Study:

• To investigate the central nervous system effects of lidocaine on auditory processing.
• To determine how intravenous lidocaine impacts auditory brain-stem responses (ABR).

Main Methods:

• Recorded auditory brain-stem responses (ABR) in six healthy males during intravenous lidocaine infusion.
• Achieved systemic lidocaine blood levels comparable to clinical anesthesia and antiarrhythmic therapy.
• Monitored subjective symptoms and objective ABR waveform changes.

Main Results:

• Lidocaine caused significant decreases in the amplitude and increases in the latency of wave V in ABR.
• Waves I and III of the ABR remained unaffected by lidocaine.
• Subjects reported transient symptoms like tinnitus and perioral numbness.

Conclusions:

• The central auditory system is a primary site for lidocaine's central nervous system effects.
• Lidocaine's impact on wave V suggests disruption of central auditory pathway function.
• ABR can detect subclinical neurological effects of systemically administered lidocaine.