A 34-year-old male presen...

A 34-year-old male presents with numbness around the lips and thumb. The numbness commenced three weeks after the patient initiated the use of metformin for insulin resistance. Physical examination reveals normal blood pressure, with no deviating pupils, dysarthria, or motor function disturbances noted. Neurological examination shows only mild paraesthesia around the lips and thumb. The patient is suspected to be experiencing a mild deficiency in vitamin B12 due to the use of metformin. Treatment includes mecobalamin administered intravenously at 500 mcg and orally for two weeks.