Lhermitte's symptom

 

Lhermitte's symptom is electric tingling in limbs and trunk following neck flexion

Suggests lesion in dorsal column of cervical cord, or caudal medulla.

 

Pathophysiology

Following demyelination and loss of axon insulation, flexion induces cross-talk involving potassium

Can occur with multiple sclerosis, myelopathy from ankylosing spondylitis, vitamin B12 deficiency, or trauma.