Medical case narrative
A 53-year-old man whose "dementia" lifted — MMSE 8 to 30
What happened
A 53-year-old man declined cognitively to a Mini-Mental State Exam score of 8 out of 30 — deep in dementia range — in the setting of B12 deficiency.
What it looked like
Severe cognitive failure that looked like an irreversible dementia.
What the labs found
Vitamin B12 deficiency. One honest note: the paper's title describes him as without anemia, but its own text records a mildly decreased hemoglobin of 12.4 and an MCV of 102 — so this entry does not repeat the "no anemia" framing. His blood counts were not normal; his B12 was the finding.
What changed
With B12 treatment, his MMSE rose from 8 to 30 — a full score.
The test that told the story
Serum vitamin B12 (with CBC — hemoglobin and MCV).
Sources: Published case report.