Lance-Adams Syndrome: A Case Study

Abstract Background: Lance-Adams syndrome (LAS) is a rare condition caused by brain hypoxia commonly due to respiratory arrest leading to chronic uncontrollable myoclonus. The myoclonus usually develops weeks to months following respiratory arrest and successful cardiopulmonary resuscitation (CPR). LAS is a rare clinical entity with as few as 150 cases reported in the medical literature. Anesthetic and surgical accidents account for the majority of respiratory arrest incidents in LAS cases. However, other inciting events include cardiac arrest, drug overdose, and suicide attempts. We present a case of a 59-year-old male who developed LAS months following cardiac arrest secondary to an anomalous cardiac artery and successful CPR. Case information: A 59-year-old male with a past medical history of anoxic brain injury secondary to cardiac arrest, congestive heart failure, cerebral vascular accident with residual left sided weakness, and seizure disorder presented to the emergency department with generalized myoclonus, despite the use of levetiracetam 500mg twice daily. After an extensive series of imaging studies and lab work neurology was consulted due to the increasing complexity of the case. Upon neurology recommendation levetiracetam was increased to 1000mg twice daily, without clinical improvement. At this time, due to the lack of MRI, CT, and EEG findings it was determined by neurology that the patient was experiencing symptoms concurrent with LAS. The diagnosis of LAS was most likely, considering the patients history of anoxic brain injury caused by cardiac arrest just 6 months prior with successful cardiopulmonary resuscitation. Neurology stopped levetiracetam and switched to valproate at a one-time dose of 500mg. The patient had complete remission of the post-hypoxic myoclonus and eventually discharged on valproate 500mg twice daily. Conclusion: In concordance with other cases of Lance-Adams Syndrome (LAS) which have been documented, this patient experienced a cerebral hypoxic event prior to the development of his myoclonus. As noted by several other authors’ presentations of LAS, this patient also did not exhibit any acute imaging findings on CT or MRI of the brain, further supporting the the lack of pathognomonic imaging findings for LAS. Of note, though unresponsive to levetiracetam, this patient’s myoclonus resolved completely with valproic acid, further validating its consideration as the first-line treatment in patients suffering from LAS.