Diagnostic Puzzle of Acute Ischemic Stroke Mimics – Seizure Versus Post-Stroke Recrudescence: A Case Report

Patient: Female, 65-year-old Final Diagnosis: Post-seizure Todd’s phenomenon Symptoms: Combativeness and aggressiveness • confusion • worsening weakness of the right upper and lower limbs Medication: — Clinical Procedure: Brain imaging: NCCT • CTA • CTP • MRI Specialty: Neurology • Radiology OBJECTIVE: Challenging differential diagnosis BACKGROUND: Focal seizure with impaired awareness, post-seizure Todd’s phenomenon, and post-stroke recrudescence can all present with focal neurological deficits, mimicking stroke. As acute ischemic stroke mimics, they are distractors in the emergency setting where management is time-sensitive both for seizure and stroke. Nevertheless, a timely diagnosis can be made with exploration of the clinical features supported by investigation such as computerized tomographic perfusion. CASE REPORT: Our patient was a 65-year-old woman who was known hypertensive, with type 2 diabetes mellitus, and previous intracerebral hemorrhage with minimal right-sided residual deficits, but still able to ambulate independently. She was brought to the Emergency Department because 1 hour prior to presentation, she had sudden worsening of weakness of the right limbs, aphasia, aggression, and confusion. An initial impression of repeat acute stroke, focal seizure with impaired awareness, Todd’s phenomenon, and post-stroke recrudescence was considered. While CT angiography was suggestive of left middle cerebral artery occlusion, CT perfusion revealed extensive hypoperfusion patterns beyond the region of the occlusion, thus suggesting a different etiology from acute ischemic stroke. In view of her previous left hemispheric lesion coupled with the presentation, our working diagnosis was seizure with Todd’s phenomenon, and she was started on an anti-epileptic drug. Her condition returned to baseline within 24 h of admission and was subsequently discharged. CONCLUSIONS: Our case demonstrates that adequate elucidation of clinical features in conjunction with CT perfusion, as a dual-purpose tool, can aid the diagnosis of both stroke mimics and acute ischemic stroke in the Emergency Department where rapid treatment is essential.