demyelinating disease (as occurs with
multiple sclerosis or other disorders; this would be seen on a good quality MRI), certain genetic disorders (such as hereditary spastic paraparesis), specific infections (such as HTLV), specific nutrional deficiencies (vitamin B12, copper, vitamin E; these are often associated with other findings on history and examination), vascular malformations (such as a dural AV fistula), autoimmune disorders (such as one called "stiff person syndrome" and an