Ischemic Amnesia Caused by Bilateral Fornix Infarction: A Rare Entity

A 50-year-old male presented with memory disturbances for the past 10 days in the form of not able to remember things that were told or not able to recollect recent or immediate events such as what he had for the breakfast. He was not a known diabetic, hypertensive, smoking, or alcohol consumption in the past. On examination, he was conscious, obeys commands, and oriented to time, place, and person. His blood pressure was 120/80 mmHg and his heart rate was 80 bpm and regular. Higher mental function examination revealed that recent and immediate memory was impaired. Remote memory was intact. The rest of cognitive and higher mental functions and other neurological examination was unremarkable. Blood investigations showed normal complete hemogram, liver enzymes, proteins, electrolytes, and renal functions. Thyroid functions and serum ammonia were normal. Magnetic resonance imaging brain plain showed T2 hyperintensities, with diffusion restriction noted in both columns of the fornix and no evidence of blooming in SWI images, suggestive of acute infarct in bilateral anterior fornix region. [Figure 1a–d]. Angiogram of cerebral vessels was not done as the patient was not willing. Echocardiogram and carotid vertebral Doppler were normal