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

Abstract

Objective

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.

Methods

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.

Results

Resting MEP amplitude was larger in the amphetamine group (6M, 6F) than the non-drug and ecstasy groups (p < 0.005) in males but not females. Overestimation of grip force during manipulation of a novel object was observed in the amphetamine group (p = 0.020) but not the ecstasy group.

Conclusions

History of illicit amphetamine use, in particular methamphetamine, is associated with abnormal motor cortical and/or corticomotoneuronal excitability in males and abnormal manipulation of novel objects in both males and females.

Significance

Abnormal excitability and hand function is evident months to years after cessation of illicit amphetamine use.

 

Click here for more details.

Related Post

  • Posted on 25 January, 2024
    Exposing healthy adults to extended periods of wakefulness is known to induce changes in psychomotor functioning. The effect of fatigue...
    • Posted on 17 January, 2024
      While speech biomarkers of disease have attracted increased interest in recent years, a challenge is that features derived from signal...
      • Posted on 17 January, 2024
        Smart devices are widely available and capable of quickly recording and uploading speech segments for health-related analysis. The switch from...