ROSH Gastrointestinal Practice Exam

What is the most likely cause of numbness and uncoordinated gait in a 38-year-old man treated for pulmonary tuberculosis?

1. Vitamin A deficiency

2. Vitamin B12 deficiency

3. Vitamin B3 deficiency

4. Vitamin B6 deficiency

The correct answer is: Vitamin B6 deficiency

The symptoms of numbness and uncoordinated gait in the context of a patient treated for pulmonary tuberculosis strongly suggest a deficiency in vitamin B6. This vitamin is crucial for the maintenance of nerve function, and deficiency can lead to peripheral neuropathy, which is characterized by numbness and coordination problems. In patients with pulmonary tuberculosis, the use of certain anti-tubercular medications, like isoniazid, can lead to pyridoxine (vitamin B6) depletion. This medication interferes with the metabolism of vitamin B6, leading to an increased risk of deficiency, especially when dietary intake may be insufficient. The resultant neuropathy manifests as numbness in the extremities and can also affect gait due to loss of proprioception. While the other vitamin deficiencies listed can certainly induce various symptoms, they are less likely to specifically cause both numbness and coordination difficulties in this scenario. Vitamin B12 deficiency, for instance, typically presents with additional neurological issues such as cognitive changes and can take much longer to manifest compared to the acute effects of vitamin B6 deficiency due to medication interactions. Thus, in this specific clinical setting, vitamin B6 deficiency is the most likely cause of the symptoms presented.