A 19-year-old woman presented with severe carbon monoxide poisoning resulting in coma, brain stem signs, cerebellar syndrome, anterograde memory disorder and some frontal signs. Nine years later, generalized seizures appeared. At the age of 31, the cerebellar syndrome and memory disorders persisted. MRI showed cerebellar and internal temporal atrophy with high-intensity signals, and hippocampal and callosal atrophy. SPECT (Xe133) showed a low cerebellar blood flow.