Sometimes called the barber chair phenomenon, is an electrical sensation that runs down the back and into the limbs.
Can be elicited by bending the head forward, and can be evoked with pounding on the posterior cervical spine while the neck is flexed.
Caused by involvement of the posterior columns.
Suggests the presence of lesion of the dorsal columns of the cervical cord or of the caudal medulla.
Is a classic finding in multiple sclerosis, but can be caused by a number of conditions, including transverse myelitis, Behçet’s disease, trauma, radiation myelopathy, vitamin B12 deficiency and compression of the spinal cord in the neck from any cause such as cervical spondylosis, disc herniation, tumor, and Arnold-Chiari malformation.
May also appear during or following high dose chemotherapy.
Irradiation of the cervical spine may be responsible.
Delayed onset has been reported following head and/or neck trauma, occurring 2 1/2 months following injury, without associated neurological symptoms or pain, and typically resolves within 1 year.
Sometimes associated with certain psychotropic medications, such as serotonin reuptake inhibitors, particularly paroxetine and venlafaxine, after withdrawal of the drug.