Does Transcranial Magnetic Stimulation Have an Added Value to Clinical Assessment in Predicting Upper-Limb Function Very Early After Severe Stroke?

Background: The added prognostic value of transcranial magnetic stimulation (TMS)-induced motor-evoked potentials (MEPs) to clinical modeling for the upper limb is still unknown early poststroke.

Objective: To determine the added prognostic value of TMS of the adductor digiti minimi (TMS-ADM) to the clinical model based on voluntary shoulder abduction (SA) and finger extension (FE) during the first 48 hours and at 11 days after stroke.

Methods: This was a prospective cohort study with 3 logistic regression models, developed to predict upper-limb function at 6 months poststroke. The first model showed the predictive value of SA and FE measured within 48 hours and at 11 days poststroke. The second model included TMS-ADM, whereas the third model combined clinical and TMS-ADM information. Differences between derived models were tested with receiver operating characteristic curve analyses.

Results: A total of 51 patients with severe, first-ever ischemic stroke were included. Within 48 hours, no significant added value of TMS-ADM to clinical modeling was found ( P = .369). Both models suffered from a relatively low negative predictive value within 48 hours poststroke. TMS-ADM combined with SA and FE (SAFE) showed significantly more accuracy than TMS-ADM alone at 11 days poststroke ( P = .039).

Conclusion: TMS-ADM showed no added value to clinical modeling when measured within first 48 hours poststroke, whereas optimal prediction is achieved by SAFE combined with TMS-ADM at 11 days poststroke. Our findings suggest that accuracy of predicting upper-limb motor function by TMS-ADM is mainly determined by the time of assessment early after stroke onset.