Anoxic encephalopathy with myoclonus – Lance-Adams syndrome

Abstract

Lance-Adams syndrome is a rare (ca. 150 cases reported so far), chronic encephalopathy developing within a few days or weeks following acute respiratory or circulatory failure. The most common reasons include: asthmatic status, cardiac arrest, gasping, drugs overdose, complications of general anesthesia. Typical symptoms include: myoclonus (provoked by purposeful movements or external stimuli), disturbances of gait, ataxia, dysarthria and cognitive dysfunction. The current studies on the electrophysiological aspects and neuroimaging in the patients with Lance-Adams syndrome allow a better insight into its pathophysiology. The background of the disease is associated with hypoxic damage to cortical and subcortical areas of the brain as well as with disrupted bioelectrical activity within the functional circuits among them and disordered neurotransmission (GABA-and serotoninergic pathways). Differential diagnosis should include myoclonic epileptic status, which occurs during acute stage of cerebral hypoxia and is associated with disturbed consciousness and severe risk of mortality. The therapeutic options were discussed, used in the patients with anoxic encephalopathy and myoclonus. The prognosis is good and the treatment with new antiepileptic medications, supported by rehabilitation, provide a chance for recovery. Lance-Adams syndrome deserves an attention as its frequency may presumably increase due to effectiveness of current methods of resuscitation and intensive care strategies.