Elderly Male with Refractory Orthostatic Hypotension

Author: Joshua Schwimmer, M.D., FACP, FASN
Reviewer: V. Dimov, M.D.

A 72-year-old man presented with severe, disabling, refractory orthostatic hypotension of two years duration. His blood pressure on standing was 74/40 despite treatment with midodrine 10 mg three times daily and florinef 0.1 mg once daily.

His physical examination, including a detailed neurologic examination, is otherwise unremarkable.

He had a partial gastrectomy for an ulcer twenty years ago. His kidney function was normal. He was slightly anemic (hemoglobin 10.9 mg/dL). His vitamin B12 level was within the normal range (297).

A diagnostic test was performed and a new medication was started as a result of the test.

After a month of treatment with an oral medication, his systolic blood pressure improved to 140s on standing and he was weaned fromflorinef and midodrine.

What was the test, and what was the treatment? (highlight the line below with the mouse to see the answer)

Answer: The test was a methylmalonic acid level (which was elevated).

This is diagnostic of vitamin B12 deficiency, which caused an isolated autonomic neuropathy and orthostatic hypotension in this patient. Vitamin B12 deficiency was likely related to his previous gastrectomy; it can be difficult to diagnose and can present with a vitamin B12 level in the normal range.

The treatment was oral vitamin B12 2000 mcg once daily. His hypotension resolved within one month.

Vitamin B12 deficiency can rarely cause an isolated autonomic neuropathy with orthostatic hypotension as the primary symptom.

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Published: 11/01/2006
Updated: 09/29/2010


  1. What diagnostic test did you do?

  2. Ben,

    Highlight after "Answer" above and you will see it.