Lhermittes Sign: Symptoms, Causes and Treatment

Lhermitte’s sign is a fascinating and sometimes alarming neurological phenomenon. Often described as an “electric shock” sensation that travels down the spine and sometimes into the limbs when the neck is flexed, it can be a crucial clue to underlying spinal cord dysfunction. But what does experiencing Lhermitte’s sign mean for a patient, and what causes it? In this article, we explore the symptoms, causes, and treatment options for Lhermitte’s sign, synthesizing insights from current research and clinical practice.

Symptoms of Lhermittes Sign

Lhermitte’s sign is a distinctive symptom, but its nuances are important to understand. Recognizing its features can help patients and healthcare providers identify when further neurological evaluation is needed.

Sensation	Trigger	Distribution	Source(s)
Electric-shock	Neck flexion	Spine ± arms/legs	2 3 4 5 6
Tingling	Neck movement	From neck down body	2 3 4 5 6
Transient	Often brief	Usually bilateral	2 5 6 12
Paresthesia	Yawning/rotation	Occasionally localized	1 4 5

Table 1: Key Symptoms

The Sensation: Electric-Shock or Tingling

Lhermitte’s sign is best described as a sudden, brief, electric-shock-like sensation. This feeling typically originates at the nape of the neck and radiates down the spine. In many cases, the sensation can extend into the arms and legs, and sometimes even to the sacrum or toes. Patients often use vivid language to describe it—terms like “buzzing,” “tingling,” or “jolt” are common 2 3 4 5 6.

Triggers: Neck Flexion and More

The hallmark trigger for Lhermitte’s sign is flexion of the neck—bending the head forward towards the chest. However, symptoms can occasionally be elicited by other movements, such as neck rotation or even yawning 1 4. The sign is typically transient, lasting only seconds, and is not usually associated with persistent pain.

Distribution: From Spine to Limbs

While the classic description involves the sensation shooting down the spine, the distribution can be broader. Some patients report the sensation spreading into both arms and legs, or more rarely, being localized to one area. The phenomenon is usually bilateral, but can be asymmetric or limited in scope 2 3 4 5 6.

Associated Features and Impact

Lhermitte’s sign is seldom painful but can be distressing, especially when it is a new or unexplained symptom. It is frequently a marker of increased disease activity in conditions like multiple sclerosis, and its appearance may coincide with other neurological changes 6 12.

Causes of Lhermittes Sign

Understanding what causes Lhermitte’s sign is essential for both diagnosis and management. The sign points to dysfunction in the dorsal (posterior) columns of the cervical spinal cord, but the underlying reasons can be diverse.

Cause Category	Examples	Mechanism/Pathology	Source(s)
Demyelinating	Multiple sclerosis (MS)	Lesions in cervical cord	3 4 6 12
Compression	Tumors, herniated discs, trauma	Mechanical dorsal column stress	4 7
Iatrogenic	Radiation, chemotherapy	Toxic/demyelinating injury	2 8 9 10 11 13
Deficiency/Toxicity	Vitamin B12, nitrous oxide	Metabolic demyelination	3 5
Infectious	Herpes zoster, inflammation	Acute dorsal column dysfunction	5
Congenital/Structural	Atlas arch defects, bullet migration	Direct cord compression	1 7

Table 2: Common Causes of Lhermitte’s Sign

Demyelinating Diseases

The most widely recognized cause of Lhermitte’s sign is multiple sclerosis (MS). In MS, immune-mediated damage leads to demyelination—loss of the insulating myelin sheath—particularly in the cervical spinal cord’s posterior columns. This disruption allows neck flexion to trigger abnormal nerve signals, resulting in the characteristic sensation 3 4 6 12.

• Up to 25% of MS patients may experience Lhermitte’s sign at some point 12.
• The sign is often associated with increased disease activity or new lesions on MRI 6.

Spinal Cord Compression

Any condition that compresses the dorsal columns of the cervical spinal cord can cause Lhermitte’s sign. This may include:

• Tumors: Both intrinsic (inside the cord) and extrinsic tumors can distort or compress the cord 4 7.
• Herniated discs or spondylosis: Degenerative changes may physically impinge upon the dorsal columns.
• Congenital anomalies: Rare defects, such as partial aplasia of the posterior arch of the atlas (C1 vertebra), can also be implicated 1.
• Trauma or foreign bodies: Even migrating objects, like an intracranial bullet, can cause the sign if they impinge on the right region 7.

Iatrogenic and Treatment-Related Causes

Cancer therapies frequently play a role in the development of Lhermitte’s sign:

• Radiation therapy: Particularly when higher doses or steep dose gradients are delivered to the cervical spinal cord, as seen with modern techniques like VMAT, the risk increases 2 10 13.
  • Incidence rates after cervical irradiation range from 3.6% up to 15% in some series 2 10 13.
• Chemotherapy: Drugs like cisplatin and docetaxel are known to cause neurotoxicity and can result in demyelinating lesions, especially at high doses 8 9 11.
  • Symptoms often resolve after discontinuation or dose reduction 8 9.

Nutritional Deficiency and Toxicity

Deficiencies in vitamin B12 (cobalamin) or exposure to neurotoxic agents like nitrous oxide can produce subacute combined degeneration, affecting the dorsal columns and causing Lhermitte’s sign 3 5.

• Correction of the deficiency can lead to symptom improvement.

Infectious and Inflammatory Causes

Acute infections such as herpes zoster (shingles) involving the cervical spinal cord or dorsal roots can transiently produce Lhermitte’s sign due to inflammation and altered nerve excitability 5.

Structural and Rare Causes

Congenital defects, such as partial absence of the C1 vertebral arch, and rare scenarios like migrating bullets, have been reported to cause Lhermitte’s sign due to direct mechanical effects on the spinal cord 1 7.

Treatment of Lhermittes Sign

Treatment for Lhermitte’s sign depends on addressing the underlying cause, but symptomatic relief is also possible. Understanding both aspects can help patients manage this distressing symptom.

Treatment Approach	Example/Method	Outcome/Effect	Source(s)
Causative therapy	Remove tumor, treat deficiency	Symptom resolution	1 3 4
Discontinue agent	Stop chemo/radiation	Gradual improvement	8 9 10 11
Symptomatic meds	Carbamazepine	Rapid relief of sensations	14
Physical therapy	Neck movement training	Reduce triggering	12
Adjunct therapies	Electromagnetic fields	Resolution in MS cases	12

Table 3: Treatment Strategies for Lhermitte’s Sign

Addressing the Underlying Cause

Whenever possible, treatment is directed at the root problem:

• Tumors or compressive lesions: Surgical removal can lead to complete resolution of symptoms 1 4.
• Vitamin B12 deficiency: Supplementation corrects the metabolic problem and often leads to improvement 3.
• Infections: Antiviral or anti-inflammatory therapies may be indicated for cases like herpes zoster 5.

Modifying or Stopping Offending Agents

If Lhermitte’s sign is caused by a medication or treatment:

• Chemotherapy (e.g., cisplatin, docetaxel): Discontinuing or reducing the dose often leads to gradual symptom resolution 8 9 11.
• Radiation therapy: Symptoms may be self-limited and resolve within months after treatment ends 10 13.
  • No cases progressed to severe myelitis in large series, suggesting a generally benign course 10.

Symptomatic Relief

For patients with persistent or distressing symptoms, medications can help:

• Carbamazepine: An antiepileptic drug, carbamazepine has shown a rapid and reproducible effect in alleviating the electric sensations of Lhermitte’s sign. Relief can occur within 24 hours, although symptoms often recur if the drug is stopped 14.
• Other medications: While less well-studied, similar agents that stabilize nerve activity may be used in some cases.

Physical and Adjunctive Therapies

• Physical therapy: Education on neck positioning and gentle movement training may help reduce symptom provocation.
• Electromagnetic field therapy: Small studies in MS patients have reported that picotesla-range pulsed electromagnetic fields can eliminate Lhermitte’s sign, possibly by reducing nerve excitability 12.
• General supportive care: Reassurance and stress management are important, as the sign itself is rarely dangerous but can be distressing.

Prognosis

The outlook for patients with Lhermitte’s sign varies depending on the cause:

• In many cases related to treatment (radiation, chemotherapy), symptoms are transient and resolve over weeks to months 8 9 10 13.
• When caused by demyelinating disease, the sign may persist or recur depending on disease activity 6 12.
• Symptomatic treatments can provide relief even if the underlying condition is ongoing 14.

Conclusion

Lhermitte’s sign is a striking neurological symptom that serves as an important signal of spinal cord dysfunction. By recognizing its classic features, understanding the wide range of potential causes, and applying targeted treatments, both patients and clinicians can address the symptom effectively.

Main Points:

• Lhermitte’s sign is characterized by a brief electric-shock sensation triggered by neck flexion, radiating down the spine and sometimes into the limbs 2 3 4 5 6.
• The sign is commonly associated with multiple sclerosis, but can also result from spinal cord compression, cancer treatments, nutritional deficiencies, infections, and rare structural conditions 1 2 3 4 5 6 7 8 9 10 11 13.
• Treatment centers on addressing the underlying cause—removing compressive lesions, correcting deficiencies, or modifying treatments—while symptomatic relief can be achieved with medications like carbamazepine or, in some cases, physical or electromagnetic therapies 1 3 4 8 9 10 11 12 14.
• Most cases are transient and resolve with appropriate intervention, but ongoing symptoms may signal active disease or require symptomatic management.

By understanding Lhermitte’s sign, patients can better advocate for their health, and clinicians can pursue precise diagnoses and individualized treatment strategies.