Bihemispheric Seizure Without Generalization.

Area of Science:

• Neurology
• Neuroscience
• Clinical Medicine

Background:

• Focal seizures typically originate from a single hemisphere and can generalize, often with impaired awareness.
• Acute subdural hematomas (SDH) are known to cause seizures, but bilateral hemispheric involvement without generalization is rare.
• Parasagittal epileptogenic lesions can be challenging to localize both clinically and electrographically.

Purpose of the Study:

• To present the first visual report of focal, bihemispheric clinical seizures with preserved awareness.
• To discuss the potential role of acute subdural hematoma in promoting bilateral epileptogenicity.
• To highlight the diagnostic challenges in localizing seizures originating from parasagittal lesions.

Main Methods:

• Case report of a 70-year-old male with recurrent jerking movements.
• Clinical examination revealing hemiparesis and weakness.
• Computed tomography (CT) scan identifying an acute subdural hematoma.
• Electroencephalogram (EEG) performed after antiseizure medication administration.

Main Results:

• The patient experienced recurrent episodes of left hemibody and right lower extremity jerking with preserved awareness.
• CT revealed a right parafalcine acute subdural hematoma.
• Seizures ceased and weakness improved following lorazepam and levetiracetam treatment.
• EEG showed non-specific theta slowing, with no epileptiform activity detected.

Conclusions:

• This case demonstrates focal, bihemispheric seizures without impaired awareness, a presentation not previously visually documented.
• The parafalcine subdural hematoma likely contributed to bilateral hemispheric epileptogenicity.
• The findings underscore the difficulty in localizing seizures from parasagittal lesions, even with normal EEG findings.