EXACERBATION OR UNMASKING OF FOCAL NEUROLOGIC DEFICITS BY SEDATIVES

Background: Transient focal neurologic deficits have been observed in patients emerging from brain tumor or carotid surgery, and a pharmacol ogic effect of anesthetic agents has been proposed as the cause of suc h neurologic dysfunction, Therefore, the effect of sedation with midaz olam or fentanyl on motor neurologic function was studied prospectivel y and preoperatively in patients with carotid disease or mass lesions of the brain. Methods: Fifty-four unpremedicated adult patients with c arotid disease or a brain tumor were given small intravenous doses of either 2.8 +/- 1.3 mg midazolam or 170 +/- 60 mu g fentanyl in the pre operative period, A thorough motor examination was performed at baseli ne and after sedation by an individual who was unaware of the details of the patient's disease or symptoms, A mental status examination also was performed to control for the effects of inattentiveness or lack o f cooperation during the neurologic examination. Results: Patients wer e sedated mildly but were fully cooperative. Focal motor deterioration occurred after sedation in 30% of patients, and the incidence was sim ilar in patients in the fentanyl and midazolam groups. Among patients with a focal motor abnormality on baseline examination or a resolved p rior motor deficit, 73% had exacerbation or unmasking of these signs b y sedation, whereas no patient without a prior history of motor dysfun ction had a sedative-induced change, Sedative-induced changes in neuro logic function ranged from unilateral mild weakness to complete plegia , but appeared to be transient in nature. Conclusions: Sedation with m idazolam or fentanyl can transiently exacerbate or unmask focal motor deficits in patients with prior motor dysfunction.