Vagus nerve stimulation for treatment of headaches, other neurological conditions

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By: Dr. John Conde DC, DACNB Special to the Boca and Delray newspapers

The vagus nerve is a cranial nerve which is housed in the skull and is often referred to as the “wandering nerve” because it is the longest nerve in the human body. It travels from the brain stem to the outer ears and all the way down to the lower intestines.  The vagus nerve is considered to be a part of the parasympathetic nervous system family, which is responsible for putting the body at rest, slowing the heart rate, enhancing digestion, sexual arousal, lacrimation (tearing), urination, normalizing blood vessel diameter, and defecation to name a few functions.  These processes are the exact opposite of the sympathetic nervous system which is considered to be responsible for “Fight or Flight” dynamics.

Ideally, the predominance of activity should involve the parasympathetic nervous system with activation of the sympathetic nervous system only when appropriate, however this has not been the case for quite some time. Due to our lifestyle and the egregious demands our society places on us daily, this ratio of activation is completely thrown off.  We develop a much greater sympathetic tone which is highly contributory to many neurological and psychological conditions. This is one of the reasons why there is such a high level of interest and research in vagus nerve stimulation and the recalibration of the ratio of parasympathetic versus sympathetic activity.

Invasive or surgical vagus nerve stimulation (VNS) involves the surgical implantation of a vagus nerve stimulator (pacemaker) for the treatment of seizures. This was FDA approved in 1997 for the treatment of seizures and then in 2005 for depression and 2015 for weight loss. However, due to the impracticality and danger associated with implantation of this stimulator researchers have been working tirelessly to ascertain a treatment modality that was non-surgical and non-invasive.  They have finally succeeded. They have taken advantage of a small patch of tissue in the outer ear termed the cymba concha which is innervated by the auricular branch of the vagus nerve and found that stimulating this area with electrical current can have significant modulatory effects on the parasympathetic nervous system.  Because the stimulation is occurring externally it is called transcutaneous vagus nerve stimulation (tVNS).

tVNS is garnering significant traction in several different medical specialties due to the wide-reaching effects this treatment can have. Headaches, specifically migraines are now being treated in many clinics with a combination of modalities that includes tVNS. The understanding is that in patients with chronic migraines there lies an irregularity in blood vessel diameter control such that vasodilation is prominent. Also an area in the brain stem that mediates head and face pain termed the trigeminal cervical complex (TCC) becomes irritated. Normalizing blood vessel diameter and activation of the TCC in the brainstem along with other targeted rehabilitation techniques can reduce migraine frequency and intensity. Other conditions being looked at for treatment include depression, tinnitus, epilepsy, pain, psychological conditions, dysautonomia, mood disorders, autism, and the global effects of aging. These are all mostly “off-label” but promising.

Dr. John Conde is a Board Certified Chiropractic Neurologist, one of only one thousand in the country. He holds diplomate status through the American Chiropractic Neurology Board. He provides specialized care for difficult cases of back neck pain, numbness-tingling, vertigo-dizziness balance disorders, fibromyalgia, migraines, AD/HD, autism, and dyslexia. His office is located at the Atlantic Grove in Delray Beach and can be reached at 561-330-6096, drconde@thecondecenter.com, www.thecondecenter.com