Hi. I have a sister who initially started complaining of a squeezing around her rib cage 3 years ago. She's 53 yrs old. Since that time, symptoms have progressed to a burning in her hamstrings, originally on the right, now on the left. Clinically, she cannot lift her feet off the floor when sitting in a chair. Lots of difficulty walking. She has burning and tingling sensation to the point she cannot stand to let her feet touch the floor or to sit in a chair without a special cushion. Now she having difficulty swallowing as well as nystagmus in her lateral gaze. She has had an MRI of the brain and complete spine without a asnything to explain the deficiencies. Her emg shows a myelopthy. Our dad died from als 33 yrs ago. It is not, as far as we know, familial. I know the chance of lightning striking twice is rare but any ideas what else could be going on? The docs (neurologist and neurosurgeon) say the MRI does not explain her deficits. Any input would be appreciated.