13 year old girl brought to office with concerns about her vision. She describes difficulty seeing at night and symptoms getting worse even though she got new glasses. Also has worsening coordination. Physical exam shows difficulty with tandem gait but not focal neurological deficits. Skin is dry and scaly. Lab shows elevated levels phytanic acid in cells. Fundoscopic examination is also shown 1. What condition does she likely have? 2. What is most likely location of the enzyme that is defective in her? 3. What is defect of this disease? 4. What is seen on fundoscope?

Neurology is the branch of medicine that focuses on the study, diagnosis, and management of conditions affecting the nervous system.