09-06-2011, 05:18 PM
A 44 year old woman is evaluated for 3 month history of progressive numbness in her feet and has loss of balance. She has no significant medical history and takes no medication except a multivitamin. Physical examination shows a normal mental status and cranial nerves. Strength is normal in the arms and mildly weak 4/5 in the legs. Sensory examination shows severe loss of vibratory sense in the fingers and in the knee and ankles. Joint position sense is diminished in the fingers and toes. Reflexes are 3+ diffuse with a bilateral extensor plantar response. Gait is wide based and unsteady. She can stand with her eyes open but fall if she closes her eyes. Complete blood count, electrolyte levels, and live function studies are normal. MRI of the cervical spine is normal.
Which of the following is the most likely diagnosis?
a) Amyotrophic lateral sclerosis
b) cerebellar tumor
c) peripheral neuropathy
d) Thoracic spinal cord compression
e) Vitamin B12 deficiency