Use of illicit amphetamines is associated with long-lasting changes in hand circuitry and control

• Published in: Clinical neurophysiology 2019-05, Vol.130 (5), p.655-665
• Main Authors: Pearson-Dennett, Verity, Faulkner, Patrick L., Collie, Brittany, Wilcox, Robert A., Vogel, Adam P., Thewlis, Dominic, Esterman, Adrian, McDonnell, Michelle N., Gandevia, Simon C., White, Jason M., Todd, Gabrielle
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Amphetamine-Related Disorders - physiopathology; Ecstasy; Electromyography; Evoked Potentials, Motor - physiology; Excitability; Female; Hand - physiopathology; Hand function; Humans; Male; Methamphetamine; Middle Aged; Motor cortex; Motor Cortex - physiopathology; Muscle, Skeletal - physiopathology; N-Methyl-3,4-methylenedioxyamphetamine; Transcranial Magnetic Stimulation; Young Adult
• ISSN: 1388-2457; 1872-8952
• DOI: 10.1016/j.clinph.2019.02.005

•Elevated corticomotoneuronal excitability is present in abstinent male amphetamine users.•Abstinent amphetamine users overestimate the grip force required to manipulate novel objects.•Elevated excitability and grip force overestimation is present months to years after ending drug use. The study aim was to determine if use of illicit amphetamines or ecstasy is associated with abnormal excitability of the corticomotoneuronal pathway and manipulation of novel objects with the hand. Three groups of adults aged 18–50 years were investigated: individuals with a history of illicit amphetamine use, individuals with a history of ecstasy use but minimal use of other stimulants, and non-drug users. Transcranial magnetic stimulation was delivered to the motor cortex and the electromyographic response (motor evoked potential; MEP) was recorded from a contralateral hand muscle. Participants also gripped and lifted a novel experimental object consisting of two strain gauges and an accelerometer. Resting MEP amplitude was larger in the amphetamine group (6M, 6F) than the non-drug and ecstasy groups (p