Successful Management of Undiagnosed Lance Adams Syndrome with Clonazepam in an Unusual Case of Myoclonus and Twitching

Case Diagnosis: Lance-Adams Syndrome (LAS) is a rare condition that can occur after successful CPR, causing posthypoxic myoclonus, which was effectively treated with Clonazepam in this case.

Case Description or Program Description: This case involves a 51-year-old female with a medical history of cardiac arrest, stroke, hypertension, chronic kidney disease (status post-right renal transplant), and anxiety, who presented to the ER after a fall. She reported weakness, spasms, and twitching in both lower extremities, which had significantly impaired her function for the past 2 days. She described the sensations as intermittent and disruptive to her daily activities. On a physical exam, action myoclonus was noted in the upper extremities, along with impaired coordination. The patient also reported discontinuing her clonazepam, which she had been taking for anxiety, three days before the onset of symptoms. An EEG during admission revealed spike-slow wave discharges, leading to a diagnosis of Lance-Adams Syndrome (LAS), a rare complication following cardiopulmonary resuscitation. Clonazepam was reintroduced at 0.5mg twice a day.

Setting: Acute Care Hospital.

Assessment/Results: This patient had undiagnosed LAS for over a year but was being treated for it unknowingly due to her anxiety therapy, and symptoms resolved once placed on a continuous regimen.

Discussion (relevance): With fewer than 150 reported cases in the literature, Lance-Adams Syndrome is exceptionally rare. This case is particularly notable due to the debilitating nature of the symptoms, as evidenced by the patient's inability to maintain stability and subsequent falls after just two days without treatment, necessitating an emergency room visit. The patient's use of clonazepam, initially prescribed for anxiety, proved to be an effective treatment in alleviating the symptoms.

Conclusions: This case highlights the rare occurrence of Lance-Adams Syndrome (LAS) following CPR. This case also demonstrates the significance of Clonazepam as a therapeutic modality in this pathology with < 150 cases in the literature.