How would you diagnose a ...

A 45-year-old man presented with abnormal sensations with numbness and tingling over bilateral lower extremities to the emergency department. He noted subjective left more significant than right lower extremity weakness. However, he denied low back pain, bowel or bladder incontinence, muscle fasciculation, gait, visual changes, or paraesthesia. The patient has no significant H/o recent travel, tick bite, rash, flu-like symptoms, or known drug allergies.

Triage vital signs were typical. Neurological examination showed hypertonicity in bilateral lower extremities with hyperesthesia over the T7-T8 regions and bilateral lower extremities. Other physical tests including head, neck, spine, lung, heart, abdomen and extremities were unremarkable. Further investigation confirmed evidence of vitamin E deficiency. The concentration of alpha-tocopherol was measured at <5.8 mg/L. In addition, the vitamin E/cholesterol ratio was 0.03 mg/mg suggesting pure vitamin E deficiency.

MRI of the brain confirmed regular intracranial appearances, including no cerebellar atrophy. MRI of the lumbar spine showed degenerative retrolisthesis of L5 on S1 with degenerative L5-S1 disk cartilage and a small left-sided disk protrusion without descending or exiting nerve root compression the figure.