Motor evoked potentials in patients with chronic whiplash-associated disorder grade II

Abstract

Background and purpose

It is common belief that psychological problems influence the persistence of complains in patients with so-called mild whiplash-associated disorders (WADs). The usefulness of motor evoked potentials (MEPs) is investigated in patients with grade II WAD and remaining complains for more than 6 months.

Patients and methods

Twenty consecutive patients, aged between 24 and 58 years, with persistent neck pain for months after a car accident were included. All patients had a magnetic resonance imaging (MRI) of the cervical spine and cord. Central (CMCT) and peripheral motor conduction times (PMCT) were evaluated by registration in the biceps brachii muscle (C5–C6) and in the abductor digiti minimi muscle (C7–C8–Th1).

Results

Thirteen patients had prolonged CMCT or/and PMCT compared to 7 with normal values. On MRI discus bulging C5–C6, without abnormal signal changes in the cervical spinal cord was observed in 6 of the patients with disturbed MEPs compared to 3 without. Out of 7 patients, who had repeated MEPs after 6 months, 3 of them had an improvement of their conduction time. The patients with prolonged MEP conduction times were older than those with normal values (p=0.007).

Conclusions

MEP examination has to be performed in all patients with persistent complains even in the absence of objective neurological signs and non-significant changes on imaging.