Lhermitte’s Sign

Synonym: Lhermitteā€™s phenomenon, Barber chair phenomenon

Definition of Lhermitteā€™s Sign

Lhermitteā€™s sign (pronounced Ler-meets) is an electric shock-like sensations, spreading along the spine in a cervico-caudal direction and into the arms and legs felt upon active or passive flexion of the neck.

Reverse Lhermitteā€™s Sign is defined when symptoms are induced by neck extension, not flexion.

Pathophysiology of Lhermitteā€™s Sign

Because flexion of the neck causes the dysaesthetic symptoms, it has been suggested that an increased mechanical sensitivity of these damaged myelinated axons in the dorsal cloumn of the spinal cord causes an abnormal origin or transmission of sensory information. 1

Neck flexion causes a mechanical stimulation of the damaged myelinated axons by lengthening and deforming the affected area of the cervical spinal cord.

Reverse Lhermitteā€™s phenomenon is said to be induced by extrinsic compression of the cervical cord and neck collar immobilization.

Causes of Lhermitteā€™s Sign

  1. Multiple sclerosis (in 1/3rd patients)
  2. Vitamin B12 deficiency ā€“ Subacute Combined Degeneration of spinal cord (in 1/4th patients)
  3. Cervical spondylosis
  4. Cervical spinal cord tumors
  5. Radiation myelopathy
  6. Head injuries
  7. Arnold-Chiari malformation
  8. High-dose chemotherapy
  9. Cisplatin neurotoxicity
  10. Nitric oxide neurotoxicity
  11. Arachnoiditis 2

Eliciting Lhermitteā€™s Sign

lhermittes sign

One patient described it as follows: ā€œWhen I bent my head, I felt a violent shock in my neck and a pain like an electric current running through my whole body, from the neck down the vertebral column into the feetā€. 3

Maneuver: Forward flexion of head (actively or passively)

Outcome:Ā Electric sensation spreading from spine into extremities (symmetrical or asymmetrical)

Lhermitteā€™s sign were elicited also by:

  1. Neck rotation, arm abduction, coughing 4
  2. Yawning 5

Video for Lhermitteā€™s Sign

Accuracy of Lhermitteā€™s Sign

Two studies found that the sensitivity of Lhermittā€™s sign is markedly poor, ranging from 3 to 17%.Ā One of these studies also found that it presented good specificity (97%) for nonspecific compressive myelopathy. 6

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