Movement disorders after hypoxic brain injury following cardiac arrest in adults.

BACKGROUND: Posthypoxic movement disorders and chronic posthypoxic myoclonus are rare complications after cardiac arrest in adults. Our study investigates the clinical spectrum, neuroimaging results, therapy and prognosis of these debilitating posthypoxic sequelae. METHODS: This retrospective study included 72 patients from the neurological intensive care unit at a University Hospital, who were diagnosed with hypoxic-ischemic encephalopathy after cardiac arrest between January 2007 and September 2018. Clinical records were screened for occurrence of posthypoxic movement disorders and chronic posthypoxic myoclonus. Affected patients were further analyzed for applied neuroprognostic tests, administered therapy and treatment response, and outcome of these movement disorders and neurological function. RESULTS: 19 out of 72 screened patients exhibited posthypoxic motor symptoms. Basal ganglia injury was the most likely neuroanatomic correlate of movement disorders as indicated by T1-hyperintensities and hypometabolism of this region in MRI and PET-CT. Levomepromazine and intrathecal baclofen showed first promising and mostly prompt responses to control these posthypoxic movement disorders and even hyperkinetic storms. In contrast, chronic posthypoxic myoclonus best responded to co-application of clonazepam, levetiracetam and primidone. Remission rates of posthypoxic movement disorders and chronic posthypoxic myoclonus were 58% and 50%, respectively. Affected patients seemed to present a rather good recovery of cognitive functions in contrast to the often more severe physical deficits. CONCLUSIONS: Posthypoxic movement disorders associated with pronounced basal ganglia dysfunction might be efficiently controlled by levomepromazine or intrathecal baclofen. Their occurrence might be an indicator for a more unfavorable, but often not devastating neurological outcome.