Rationale:
Moyamoya disease is a rare, progressive intracranial vasculopathy that can present with a variety of neurologic symptoms including ischemic events, hemorrhages, seizures, and migraine-like headaches. Its overlap with other neurologic syndromes can delay diagnosis and treatment.
Methods:
We report the case of a 29-year-old, right-handed woman who presented with chronic migraine featuring visual aura and right hemiparesis, consistent with sporadic hemiplegic migraine. Despite multiple treatment trials, her symptoms progressed following a COVID-19 infection. Brain MRI and vascular imaging revealed bilateral frontal and left temporoparietal subacute infarcts and findings consistent with left moyamoya disease, confirmed via digital subtraction angiography (DSA) as Suzuki stage III involving the left middle cerebral artery (MCA). She underwent left superficial temporal artery (STA)-MCA bypass surgery. A year later, she developed episodic word-finding difficulty, prosopagnosia (described as inability to recognize her husband’s face while still recognizing his voice), inability to recognize familiar street signs, and automatisms. These episodes lasted for about 30-90 seconds. Repeat cerebral angiogram was not suggestive of active moyamoya vasculopathy bilaterally. EEG showed left temporal sharp waves and slowing. Events resolved with levetiracetam.
Results:
This case highlights the diagnostic complexity of overlapping syndromes in a young adult with evolving neurologic symptoms. All patients with atypical migraine need to be screened with neuroimaging. While initially diagnosed with hemiplegic migraine, neuroimaging helped uncover underlying moyamoya disease. Post-revascularization, she developed temporal lobe epilepsy with focal cognitive symptoms including ictal prosopagnosia. Prosopagnosia was classically thought to be associated with bilateral fusiform gyrus lesions; however, recent research indicates it is more commonly associated with right temporo-occipital lesions. Interestingly, the EEG findings of our patient suggested a left hemispheric focus, highlighting a possible dissociation between clinical symptomatology and EEG localization.
Conclusions:
Ictal prosopagnosia is a rare manifestation of seizures, most often linked to lesions in the nondominant hemisphere. This case describes ictal prosopagnosia associated with EEG discharges and MRI pathology localized to the left hemisphere. This highlights the importance of recognizing atypical seizure semiology and lateralization when evaluating episodic events. Further research is needed to better understand the network dynamics that give rise to ictal prosopagnosia.
Funding: No funding was received for this abstract.