Case Highlights How Symptoms of Cobalamin Deficiency Can Mimic MS

A recently published report describes the case of a 69-year-old female patient with cobalamin deficiency who was mistakenly diagnosed with primary progressive multiple sclerosis (PPMS).

Following a diagnosis of PPMS by her primary neurologist, the patient presented to an MS clinic for a second opinion. In addition to experiencing falls and migraines for a long period of time, she also began to suffer from hand and leg weakness and numbness, paresthesia, Lhermitte’s sign, slurred speech, impaired concentration, and urinary urgency and hesitancy. She reported that her symptoms progressed quickly and she required use of a cane within a few months time.

Prior to her PPMS diagnosis, laboratory findings revealed that the patient had low levels of cobalamin (56 pg/mL) and her cervical spine MRI “showed T2 hyperintensity extending from C4 to C6, with changes typical of cobalamin deficiency.” She was administered 2 doses of cobalamin 1000μg intramuscularly (IM; 2 months apart), however, no benefit was observed.

Although non-specific, white matter changes were seen on the patient’s brain MRI, therefore, the possibility of MS was pursued. Despite normal results from various studies and tests (nerve conduction studies, anti-aquaporin-4-antibodies, cerebrospinal fluid constituents, immunoglobulin G index), the patient was prescribed intravenous methylprednisone followed by oral prednisone. However, no improvement was observed, and she was diagnosed with PPMS and recommended to initiate ocrelizumab.

At the MS clinic, lab findings revealed a low cobalamin level (97 pg/mL) and anti-intrinsic factor (IF) antibodies; hemoglobin and mean corpuscular volume were found to be normal. “Given these results and the patient’s symptoms and history, she was diagnosed in our center with cobalamin deficiency,” the study authors reported. They added, “The etiology of the cobalamin deficiency in this case was felt to be autoimmune due to the presence of IF antibodies in the absence of recent cobalamin supplementation (which can cause false positive anti-IF antibodies) and lack of other causes.”

The patient was initiated on cobalamin 1000μg IM administered monthly as well as cobalamin 1000μg sublingual tablets administered twice daily. She reported experiencing resolution of her symptoms 3-4 weeks after starting therapy and no longer needed a walking aid 2 months later.

“This case highlights the importance of careful clinical assessment and appropriate interpretation of laboratory and radiological findings in the differential diagnosis of myelopathy,” the study authors stated. Because delayed diagnosis of cobalamin deficiency can result in irreversible neurologic symptoms, an accurate and timely assessment and diagnosis is imperative. “High doses of cobalamin supplementation may be required to achieve therapeutic response,” they concluded.

For more information visit bmj.com.