What is Lhermitte Sign?
Lhermitte’s sign, also known as the barber chair phenomenon, is a brief feeling of an electric shock that travels down the spine and into the extremities when the neck is moved or flexed. It was first noted by Marie and Chatelin in 1917, but it mistakenly got credited to Babinski and Dubois initially. Later, it was correctly linked to Jean Jaque Lhermitte through significant research. He found this sign in patients with multiple sclerosis and other spinal cord diseases, and it was thought to be due to irritation and inflammation in the spinal cord, specifically in the back and side columns.
Lhermitte’s sign is also listed as one of the sudden pain syndromes of multiple sclerosis, a chronic disease that affects the central nervous system mainly due to an overreactive immune system. This condition is a leading cause of neurological disability in young adults worldwide. It can cause many other neurological symptoms, including painful vision loss, weakness in one side of the body or in arms/legs, altered sensation, discomfort, tingling or prickling sensations, urinary and/or bowel incontinence, double vision, flickering vision, dizziness, unsteady walk, inability to judge distances, tremors, facial weakness, and altered sensation in one side of the body. It’s worth mentioning that Lhermitte’s sign is not the same as the Uhthoff phenomenon, another symptom seen in patients with multiple sclerosis which is characterized by sensitivity to heat after being in a hot environment for an extended period, like saunas and hot tubs.
What Causes Lhermitte Sign?
Lhermitte’s sign (LS) isn’t a disease, but more of a sign or symptom. It suggests the presence of damage or pressure on certain portions of the lower brain or uppermost part of your spinal cord. It’s a sudden feeling, often described as neuropathic pain, which can occur due to damage to the protective covering of nerve cells in the brain and/or spinal cord. This sensation gets triggered when you move or flex your neck. To be more precise, what happens is that when you move your neck, it activates pain pathways in your spinal cord, but these pathways have been made oversensitive due to the initial damage.
An MRI scan can often reveal plaque buildups in the neck portion of your spinal cord, which is seen in 95% of people with reported LS in comparison to just 52% of people who did not report LS.
There are various health conditions that have been associated with LS, in addition to multiple sclerosis. These include conditions like Behcet’s disease, transverse myelitis, systemic lupus erythematosus (a disease where your body’s immune system attacks your tissues and organs), herpes zoster, Arnold-Chiari malformation (a condition where brain tissue extends into your spinal canal), tumors that cause pressure on the spinal cord, cervical spondylitis (swelling and inflammation in your neck joints), syringomyelia (a rare disorder in which a cyst forms within your spinal cord), vitamin B12 deficiency, nitric oxide toxicity, and damage of the spinal cord due to radiation or chemotherapy. Particularly, it’s more frequently observed in patients with damage to the protective cover of nerve cells of their neck and abnormal nerve signal transmissions. But, LS is not a definite sign for any of these disorders. Flexing of the neck irritates the damaged nerve pathways in the spinal cord, causing the electrical-feeling sensation experienced by patients.
Risk Factors and Frequency for Lhermitte Sign
Lhermitte’s sign is a condition that’s not well studied, and thus data on how frequently it occurs is varied and limited. However, among those with Multiple Sclerosis (MS), it’s been observed in about 9% to 41% of patients. In a recent study from 2015 involving about 700 MS patients, around 16% of them experienced Lhermitte’s sign. But in an older study from 1982, about 33.3% of patients reported having it, with 16% of those experiencing it during their first MS episode.
Although Lhermitte’s sign isn’t very common in MS patients, if it’s present, it’s highly likely (97% chance) that compressive myelopathy, a spinal cord condition, is the cause. When looking at the prevalence of Lhermitte’s sign in MS patients compared to neuromyelitis optica (NMO) patients, the symptom is significantly less common in MS patients (4.3%) than in NMO patients (20.5%). The symptom is also more popular in NMO patients who have a family history of Lhermitte’s sign (12.5%), compared to MS patients with a family history (5.9%). While Lhermitte’s sign typically goes away on its own after a few weeks, some patients have reported a rise in frequency and intensity of pain.
The prevalence of Lhermitte’s sign in other less common conditions such as vitamin B12 deficiency, Behcet disease, and SSRI discontinuation syndrome, among others, has not been widely studied.
Signs and Symptoms of Lhermitte Sign
Lhermitte’s sign is a symptom where patients feel a shock-like pain running from their head, down their back, and through their arms and legs. It’s often triggered by various actions and conditions such as moving the neck, experiencing fatigue, stress, heat and even yawning. This jolt of pain particularly occurs when someone bends their neck down to touch their chin to their chest. Interestingly, it’s not just neck bending, but also extending the neck can trigger what’s known as ‘reverse Lhermitte’s sign’.
- Moving the neck
- Experiencing fatigue
- Undergoing stress
- Being exposed to heat
- Yawning
- Bending the neck down, touching the chin to the chest
- Extending the neck (reverse Lhermitte’s sign)
Testing for Lhermitte Sign
When it comes to Lhermitte’s sign, a symptom often linked to multiple sclerosis and some other conditions, there’s no standard test your doctor will use to confirm or manage it. Some recent studies have found a connection between Lhermitte’s sign and certain findings on radiographs (like X-rays) and electrodiagnostic tests (tests that measure electrical activity in your nerves).
One such study found a significant link between the presence of Lhermitte’s sign, visible nerve damage on a neck MRI scan, and a delay in the conduction (or transmission) of sensory signals in the median (wrist) and tibial (lower leg) nerves. This was shown using a test called somatosensory evoked potentials (SSEP), which measures the electrical signals of your sensory nerves. These findings were significant both in terms of clinical (relating to patient care) and statistical (relating to data analysis) outcomes.
However, the general agreement among medical professionals is that a proper account of your symptoms and a physical examination by your doctor is usually enough to assess Lhermitte’s sign.
Treatment Options for Lhermitte Sign
Lhermitte’s sign, a symptom often associated with various health conditions, usually doesn’t cause severe pain or discomfort. In many cases, it resolves on its own over time. As there’s not a lot of high-quality research into how to treat Lhermitte’s sign, doctors often recommend dealing with the root health issue. This could involve treating a disease like multiple sclerosis (MS) or addressing any physical issues that might be putting pressure on and damaging the patient’s nerves.
Some studies have mentioned anecdotal evidence that medications like carbamazepine, oxcarbazepine, and gabapentin might help some patients. These medications work by reducing abnormal electrical activity in the brain which can help manage pain.
Research also suggests that in future, severe nerve-related pain due to MS might be treated by reducing inflammation, increasing the health-giving effects of certain substances called cytokines, or blocking the movement of inflammation-causing cells to the brain and spinal cord. Exact treatments using these methods aren’t available yet.
Interestingly, a few patient case studies have shown that a therapy using weak electromagnetic fields can relieve Lhermitte’s sign. It’s thought that this therapy might reduce nerve excitability or alter pain control systems in the body. However, it’s important to remember that these theories are still being studied and this therapy is not yet widely accepted nor available.
What else can Lhermitte Sign be?
: Lhermitte sign, apart from Multiple Sclerosis (MS), can indicate a number of other conditions according to medical literature. These might include:
- Tumor progression causing spinal cord compression
- Radiculopathy (a condition where a nerve or nerves along the spine are compressed)
- Cervical spondylitis (inflammation of the spinal joints in the neck)
- Transverse myelitis (inflammation of the spinal cord)
- Degeneration of the spinal cord
- Radiation myelopathy (spinal cord damage from radiation)
- Parasitic invasion of the spinal cord
- Arnold-Chiari malformation (a condition where brain tissue extends into the spinal canal)
- High dose chemoradiation
- Trauma
- Arachnoiditis (inflammation of the membranes around the spinal cord)
- Herpes zoster toxicity
- Syringomyelia (cyst formation within the spinal cord)
- Behcet disease (rare disorder causing blood vessel inflammation)
- Vitamin B12 deficiency
- Nitric oxide toxicity
- Systemic lupus erythematous (an autoimmune disease)
- Post-dural puncture headache (a complication from certain medical procedures)
What to expect with Lhermitte Sign
Lhermitte’s sign is not an illness in itself, but a phenomenon that usually occurs intermittently when the neck is bent. The long-term outlook or prognosis for the disease which causes Lhermitte’s sign varies widely.
Possible Complications When Diagnosed with Lhermitte Sign
Lhermitte’s sign doesn’t typically result in any complications. However, it is sometimes linked with withdrawal syndrome, a condition that can arise when certain medications are discontinued. This has been noted in particular with certain mental health drugs such as SSRIs and SNRIs. Paroxetine and venlafaxine are examples of such drugs connected with the appearance of Lhermitte’s sign. On the reverse side, Fluoxetine, due to its long half-life, is less likely to cause Lhermitte’s sign if suddenly stopped. Paroxetine, with its shorter half-life, has a higher likelihood to cause withdrawal syndrome. An unusual connection to Lhermitte’s sign comes from dentistry where studies show that it may be tied to abuse of laughing gas or nitrous oxide, due to it causing a decrease in vitamin B12.
Drug-related Connections:
- SSRIs and SNRIs
- Paroxetine and venlafaxine
- Fluoxetine – less likely to cause Lhermitte’s sign when suddenly stopped
Other Connections:
- Nitrous Oxide abuse in dentistry leading to Vitamin B12 depletion
Preventing Lhermitte Sign
Doctors don’t usually need to do anything besides explaining and reassuring patients that this condition usually gets better by itself over a span of a few months to a year. However, in rare cases, if the condition is stubborn and keeps returning, medication designed to manage nerve pain may be used for treatment.
