Margaret A.WinkerMD, Senior EditorIndividualAuthorPhil B.FontanarosaMD, Senior EditorIndividualAuthor
To the Editor.—I was surprised that
in the evaluation of a 56-year-old woman with chronic fatigue1
and in the discussion of the differential diagnosis that followed, no consideration
was given to B12 deficiency. Fatigue, memory loss, weakness, changes
in mood, and visual loss have all been reported to be associated with B12 deficiency in the absence of anemia and macrocytosis.2
B12 deficiency has also been reported to cause reversible white
matter lesions on magnetic resonance imaging scan.3
Thus, determination of a serum B12 level and, in borderline cases,
serum methylmalonic acid and homocysteine levels4
should be part of the routine evaluation of a patient with chronic fatigue.
I would be interested to learn this patient's B12 level.
Devitt NF. Chronic Fatigue Syndrome. JAMA. 1998;279(6):431-433. doi:10-1001/pubs.JAMA-ISSN-0098-7484-279-6-jac81007