s disease,[1] trauma, radiation myelopathy,[2] vitamin B12 deficiency (subacute combined degeneration), and compression of the spinal cord in the
neck from any cause such as cervical spondylosis, disc herniation, tumor,
and Arnold-Chiari malformation. Lhermitte's Sign may also appear during or following high dose chemotherapy. [3]
This is the Wikipedia definition of this "phenomenon" and actually there are quite a few people on there that have it...but not me...