Bilateral anterior fornix infarction: the “amnestic syndrome of the subcallosal artery”

Excerpt

A 74-year-old, left-handed female patient developed an awakening sudden anterograde amnesia with headache. The memory of events occurring in the last 3 months was also lost. She had a prior medical history of right mastectomy several years ago and chronic arterial hypertension treated with bisoprolol and ramipril. On admission, her blood pressure was 150/80 mmHg. The neurological examination was otherwise normal. Cranial computerized tomography and EEG were unremarkable. A transient global amnesia was first suspected. However, the memory disturbances persisted the day after admission and brain magnetic resonance imaging (MRI) revealed a bilateral acute infarction of both anterior columns of the fornix and posterior part of the corpus callosum genu (Fig. 1). Angio-MRI showed an anterior cerebral artery stenosis (A1 segment) with absent anterior communicating artery (ACoA). Ultrasound Doppler of the cervical arteries, transoesophagal echocardiography, and 24 h Holter-ECG were normal. Blood tests revealed a mild hypercholesterolemia. The neuropsychological testing was performed on day 5. A working memory deficit affecting the phonological loop was associated with verbal anterograde amnesia (encoding deficit) and reduced capacities on visual long term memory. Recognition memory was preserved. There was no other attention, executive, language, or gestual disorder. Signs of callosal disconnection syndrome (such as left-hand ideomotor apraxia, agraphia, tactile anomia, or alien hand) were not found. She was treated with a low dose of aspirin (80 mg/day) and clopidogrel (75 mg/day). 3 months later, the episodic memory disorders did not significantly improve.

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