Final answer:
The patient's symptoms suggest a diagnosis of methylcobalamin deficiency.
Step-by-step explanation:
The patient's symptoms of creeping paresthesias and burning pain in the left anterolateral thigh, along with normal deep tendon reflexes (DTRs) and no weakness, suggest a diagnosis of methylcobalamin deficiency. Methylcobalamin is a form of vitamin B12 that plays a crucial role in nerve function. Deficiency of methylcobalamin can lead to neuropathy, which can cause symptoms such as paresthesias and pain.