More than two thirds of those with Multiple Sclerosis experience what is known as “Lhermitte's Sign” or “The Barber's Chair Symptom”. It is a sensation of buzzing, tingling and electric shocks brought about by lowering the head as to bring the chin closer to the chest. These sensations are usually felt in the spine, arms, and legs.
There are many things that can lead to Lhermitte's Sign such as injury or side effects of medications but in Multiple Sclerosis it is typically the result of a lesion in the cervical spine (or neck). When the head is tilted downwards, the demyelinated nerves in the neck stretch causing erroneous electrical signals to be triggered which then causes parasthesia (the sensation of buzzing, tingling and electric shocks).
Lhermitte's Sign causes parasthesia which symptoms include but are not limited to:
Pins & Needles
Sensations of electric shock
The Barber's Chair Symptom
Ever wonder why it's sometimes called “The Barber's Chair Symptom”? What does a barber typically ask you to do when they need to trim your neck line? They ask you to tilt your head down, chin to chest!
In some cases, Lhermitte's Sign can be treated with medications such as Anticonvulsants (Anticonvulsants are used to treat epileptic seizures) like Neurontin (Gabapentin) or Lyrica to block abnormal electrical signals in the brain. Others choose to wear a restrictive collar/brace that helps limit the range of movement that can be achieved with the neck in order to prevent positioning the spine in such a way that would trigger the sensations of paraesthesia. When this option is chosen it is important to make sure with your therapist that your neck does not grow weak or loose range of motion over time. In some cases, a physical therapist may also set you up with a tens machine (transcutaneous electrical nerve stimulation) which uses small electrodes that stick to your skin, attach to a small battery pack, and delivers a small pulsing electrical signal which can block pain receptors