Case history
Case history
A 68-year-old man presents for a routine physical exam and follow-up for his hypertension, hyperlipidemia, and hypothyroidism. He complains of mild fatigue but is otherwise healthy. Laboratory evaluation is remarkable for a hematocrit of 34, with an MCV of 110 fL. On further query, he denies alcohol use and any other symptoms.
Other presentations
Patients with vitamin B12 deficiency may present with neurologic signs and symptoms (e.g., due to subacute combined degeneration of the spinal cord [caused by upper motor neuron lesions] and/or peripheral neuropathy [caused by lower motor neuron lesions]). Patients may have signs and symptoms of upper and lower motor neuron lesions, such as dysesthesia/paresthesia, ataxia, muscle weakness, and hyperreflexia. Reflexes may be increased, decreased, or absent depending on the location of the lesions.
Clinicians should consider testing for vitamin B12 deficiency in patients complaining of neurologic symptoms, even if vague, as early treatment may prevent permanent neurologic damage. There may be a role for testing for occult deficiency in patients with mild cognitive impairment or dementia, but more research is needed to determine which vitamin B supplements are of benefit for these patients.[7][8][9]
Megaloblastic anemia with hypersegmented polymorphonucleated cells is a classic finding in vitamin B12 deficiency, but typically presents in the later stages of deficiency.
Use of this content is subject to our disclaimer