Clinical Reasoning: A 28-year-old woman with lower extremity spasticity and microcytic anemia.

SECTION 1 A 28-year-old woman with a medical history of asthma, diabetes, and morbid obesity broke her right leg 3 years prior to presentation related to slipping on icy ground. She underwent surgical intervention for a tibial fracture, followed by a lengthy rehabilitation process. She never regained her previous walking ability and in fact felt that her balance was worsening. She stumbled frequently, tripping over small obstacles or uneven ground, and had 3 falls over 6 months prior to presentation. She had lost about 100 pounds after a gastric banding procedure done shortly before her accident. She denied weakness or clumsiness in upper extremities, headaches, vertigo, lightheadedness, or loss of consciousness. There was no history of fever, chills, autoimmune disorders, skin rash, joint pain or swellings, blood clots, or miscarriages. No relevant family history of neurologic disorders was present. On examination, she was noted to have a right foot drop, increased tone and hyperreflexia in lower extremities with a positive Babinski sign, and several beats of ankle clonus bilaterally. Her gait was slightly widebased and unsteady and she had difficulties with tandem gait. Higher cognitive functions, speech, oculomotor examination, strength in upper extremities and the left leg, and sensory examination including pinprick, light touch, temperature, vibration, and proprioception was normal. She had normal coordination in upper extremities and mild difficulties with heel to shin testing bilaterally related to spasticity.