Named after the person who first described it Jacques Jean Lhermitte, the condition also known as Barber's Chair Phenomenon, and erroneously referred to as Llermitte's Sign, characterises an electric-shock like sensation felt down the spine when the head is flexed forwards.
Most often associated with multiple sclerosis it can occur in other conditions where trauma exists in the cervical portion of the spinal cord. Conditions such as electrolyte imbalance, cervical cord tumour, cervical spondylosis, or even vitamin B12 deficiency.
I have experienced this, where the sensation shoots down the spine, but in some case it can radiate out through the arms or legs.
As the cause of the Lhermitte's sign is thought to result from the spread of ectopic excitation in demyelinated plaques in the cervical and thoracic regions of the spinal cord, it is hypothesized that the effects of EMFs are related to the reduction of axonal excitability via a mechanism involving changes in ionic membrane permeability
It is most likely that any occurrence of Lhermitte's Sign will require no treatment. Like many MS symptoms it will appear and disappear unexpectedly.
- Extracranial picotesla range pulsed electromagnetic fields