Background
Subacute combined degeneration of the spinal cord (SACD) is a potentially reversible neurodegenerative disease characterized by subacute demyelination of the dorsal and lateral column of spinal cord mainly caused by vitamin B12 deficiency. Manifestations of SACD include motor weakness, paresthesia, impaired proprioception, and gait disturbance. SACD can be treated by vitamin supplement when the cause of disease is vitamin B12 deficiency. However, the extent of neurological recovery might be variable depending on the duration and severity of neurodegeneration. Therefore, prompt diagnosis and initiation of treatment is essential. Vitamin B12 deficiency can be caused by several reasons, including pernicious anemia, surgical removal of stomach, and malnutrition.
We experienced a patient, who had a history of preceding prolonged malnutrition and was already diagnosed and treated accordingly Wernicke encephalopathy(WE), but showed gradual aggravation of neurologic deficits and later diagnosed with SACD. The initial neurologic deficits related to SACD were difficult to be detected because the patient showed confused mentality, poor cooperation and fatigability due to WE.
Case
A 76-year-old man, who has a preceding history of 5 months of malnutrition, presented to an emergency department for general weakness, confusion, and ophthalmoparesis. The brain magnetic resonance imaging (MRI) showed no other abnormal finding except for the impression of WE. The patient was diagnosed with WE and treated with 10 days of intravenous thiamine and multivitamin. After treatment, although the symptoms of WE improved, patient still presented motor weakness of extremities and difficulty in performing activities of daily living. After the mental status improved, the patient underwent follow-up neurologic exam. The patient presented grade 0 in both lower extremities, and grade 3 in both upper extremities assessed by medical research council scale, hypesthesia in all extremities, loss of deep anal pressure sensation and spontaneous anal contraction. We performed spine MRI and it demonstrated abnormal hyperintense signal changes of the posterior and lateral columns from the medulla oblongata to the thoracic spine on T2-weighted image. (Figure 1) At that point, the reported laboratory test results showed increased levels of cobalamin of 3093pg/ml but the result was supposed to be due to previous multivitamin injection.
Conclusion
Patients with prolonged malnutrition are at high risk of vitamin B complex deficiency which can cause severe neurologic symptoms. Elderly patients can make diagnosis difficult due to inaccurate expression, underlying or co-existing disease. Therefore, if there is any clinical risk of vitamin deficiency, clinicians should be cautious in several neurologic disease like SACD with high suspicion, and can diagnose and treat early with appropriate diagnostic tools. |
