Sub-acute combined degeneration with an initially normal level of vitamin B12: a case report

Fadi Makdsi,Tareck Kadrie

doi:10.4076/1757-1626-2-6944

Fadi Makdsi, Tareck Kadrie

Open Access

https://doi.org/10.4076/1757-1626-2-6944

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Journal: Cases Journal	Publication Date: Jan 1, 2009
Citations: 9	License type: cc-by

Affiliation: University of Tennessee at Chattanooga

Abstract

IntroductionThe neurological manifestation of vitamin B12 deficiency can occur as a result of peripheral nerve pathology or lateral and posterior column involvement, also known as “sub-acute combined degeneration”. This case report demonstrates an unusual presentation of SCD with normal B12 level.Case presentationA 39-year-old man was referred to the outpatient neurology clinic with a two month history of distal upper extremities numbness and fine motor movement difficulties. Initial vitamin B12 level was normal. A repeat MR imaging of the cervical and thoracic spine showed extensive posterior cervical cord flame-shaped lesions. His repeat vitamin B12 level was 41 pg/ml (normal; 200 ph/ml). He received monthly injections of vitamin B12. After six months his symptoms were resolved and his repeat spinal MRI showed resolution of the previous lesions.ConclusionWe recommend that every patient presenting with numbness and lesions on a spinal MR imaging should have their vitamin B12 level checked.

Highlights

Introduction: The neurological manifestation of vitamin B12 deficiency can occur as a result of peripheral nerve pathology or lateral and posterior column involvement, known as “sub-acute combined degeneration”
This case report demonstrates an unusual presentation of sub-acute combined degeneration (SCD) with normal B12 level and emphasizes the importance of measuring methylmalonic acid and homocysteine if vitamin B12 level is in the low normal limit
Multiple investigations and delayed diagnosis might have been prevented if his metabolite was measured first. His spinal magnetic resonance imaging (MRI) suggested the diagnosis of myelopathy and the diagnosis of vitamin B12 deficiency was confirmed by repeating the serum vitamin B12 level and checking the levels of methylmalonic acid and homocysteine

Summary

Introduction

Vitamin B12 deficiency is a common disorder. Its manifestations can range from asymptomatic to megaloblastic anemia. We present a patient with progressive neurological symptoms including numbness and fine motor movement difficulties His borderline level of serum vitamin B12 initially led to an extensive workup and relative delay in the diagnosis of vitamin B12 deficiency as the cause of his symptoms. Case presentation A 39-year-old African American man was referred to the outpatient neurology clinic with a two month history of distal upper extremities numbness and fine motor movement difficulties He denied any neck pain, lower extremity symptoms, vision loss or any other neurological deficit. Extensive laboratory evaluation was unremarkable including: basic chemistry profile, erythrocyte sedimentation rate, TSH, angiotensin converting enzyme, hemoglobin A1C, RPR, ANA, RF, serum protein electrophoresis, iron studies, Lyme IgG antibodies and heavy metals screen His repeat Vitamin B12 level was 41 pg/ml, Methylmalonic acid 5.7 umol/l (normal; 50 nmol/l (normal; 5-18 nmol/l), folate 12.7 ng/ml. After six months his symptoms were resolved and his repeat spinal MRI showed resolution of the previous lesions

Discussion

Conclusion