Systematic review for the early prediction of motor and functional outcome after stroke by using motor-evoked potentials.

OBJECTIVE: To clarify the prognostic value of motor-evoked potentials (MEPs) in predicting motor and functional outcomes after acute stroke. DATA SOURCES: A computer-aided search to identify original prognostic studies published from 1988 through 2000; relevant references cited in the retrieved articles were also included. STUDY SELECTION: A preliminary screening selected studies in which transcranial magnetic stimulation was assessed as a prognostic determinant for outcome at the level of impairments (motor recovery) and disabilities (functional recovery). The studies were then subjected to a critical review according to a priori methodologic criteria. DATA EXTRACTION: Data from the studies were used to construct contingency tables with MEPs as a prognostic determinant. The distribution of cells was statistically assessed with the Fisher exact test. The prognostic test properties were expressed as sensitivity and specificity. The clinical significance was determined by odds ratios. DATA SYNTHESIS: Of 85 potentially relevant studies, 20 met the criteria for the preliminary screening; after the critical review, 5 studies were included for analysis and discussion.
CONCLUSIONS: Analysis of the data from the 5 studies indicated obvious evidence for the prognostic value of MEPs for both motor and functional recovery. The prognostic test properties for subgroups of patients could be established. In predicting motor recovery of the upper extremity, the specificity was consistently very high for subgroups of patients with paralysis or severe paresis; this test property might be used in clinical practice. We discuss the prognostic value of MEPs and offer suggestions for further research.