What is Lhermitte Sign?
Lhermitte Sign differentiates between spinal cord lesions and peripheral nerve root lesions.
How it's Performed?
- The patient sits with outstretched legs on the examination table.
- The examiner grasps the patient’s foot with one hand and places the other on the back of the patient’s head.
- The examiner then simultaneously flexes the outstretched leg at the hip and increasingly flexes the cervical spine.
What does a positive Lhermitte Sign mean?
- The Lhermitte test is positive if an acute pain occurs that radiates into the upper or lower extremity.
- This suggests dural or meningeal irritation of the spinal cord (root irritation) or possibly cervical myelopathy.
- If the patient were to actively bend the head toward the breast, then this would be the Soto-Hall test.
- Maximally flexing the cervical spine places strong tension on the spinal cord.
- A positive Lhermitte sign can indicate stenosis of the cervical spinal canal:
- The patient describes a sudden, generalized electric shock in the arms and trunk, especially when inclining the head.
Sensitivity & Specificity
- Sensitivity: 3 – 17%
- Specificity: 97% (for non-specific compressive myelopathy)
- Spinal stenosis is usually of bony origin from pronounced spondylosis and spondylarthritis as a result of a degenerative intervertebral disk injury.
- Early symptoms are abnormal sensations in the hands, gait disorders, and clumsiness of the hands (disturbances of fine motor function, writing and grip).
- Differential diagnosis for patients with a positive Lhermitte Sign:
- Brachial plexus lesion
- Irritated cervical root syndrome
- Multiple sclerosis
- Spinal tumor.
- Amyotrophic lateral sclerosis.
- Clinical Tests for the Musculoskeletal 3rd Ed. Book