Author Response: Clinical Reasoning: A 70-Year-Old Man With Right Arm and Leg Shaking.

Abstract

We appreciate the comments from Drs. Freund and Tatum and agree that frontal lobe seizures are an important consideration.1 In small studies of patients with frontal lobe epilepsy, the ictal EEG was obscured by an artifact or seemed normal in only 1.5% of cases localized to the dorsolateral frontal cortex. However, up to 50% of cases were localized to the medial frontal cortex.2 Our patient had bilateral symptoms of increased muscle tone and an impaired ability to speak upon presentation, which persisted throughout the duration of continuous EEG.1 The EEG demonstrated generalized slowing without evidence of epileptiform abnormality. The patient gradually improved in the timeline expected after acute stroke, without intervention of antiepileptic treatment.1 For this reason and those outlined in our article, we believe stroke is the most likely cause of the patient's symptomology. The co-occurrence of acute stroke and seizure has previously been reported to be as high as 9%, with most cases representing nonconvulsive status epilepticus (NCSE), as opposed to convulsive seizures.3 Although it is unclear whether the co-occurrence of acute stroke and status epilepticus leads to higher mortality rates, there is evidence that this incidence leads to higher rates of functional disability.4 Therefore, we agree it is important to consider seizure in the differential diagnosis of a patient presenting with acute stroke, despite a negative surface EEG.