Evaluation and Treatment of Post-Traumatic Trigeminal Neuralgia
By Steven J. Anglés
September 12, 2013
Trigeminal neuralgia (TN) is a rare and painful neuropathic condition that affects the trigeminal, or 5th cranial nerve, one of the most widely distributed nerves in the head.  While the cause of TN in some patients may be genetic, TN can also result from trauma to the brain or face as can happen in a motor vehicle collision Symptoms of TN are most commonly described as a sudden, unilateral, brief, stabbing, recurrent pain which lasts from a few seconds to 2 minutes. The frequency of onset can range from few to hundreds of attacks per day, that are sudden or constant, and pain levels may range from an aching, burning sensation to a more severe pain. Most troublesome from a patient perspective is that these intense onsets of pain can be triggered by even relatively light vibration or contact with the cheek, such as when shaving, washing the face, applying makeup, brushing teeth, eating, drinking, talking, or being exposed to the wind.  While TN is not fatal, its intense symptoms have led to its more common name – “suicide disease”.
The generation of TN pain is thought to result from peripheral pathology (i.e. neurovascular compression) and central pathophysiology (i.e. hyperactivity of the trigeminal nerve nucleus).
The trigeminal nerve consists of three nerve root branches that innervate ophthalmic, maxillary, and mandibular areas. These branches provide sensation and feeling to the upper, middle, and lower portions of the face (respectively) and oral cavity, to the brain. TN is associated with a variety of anatomical conditions. For example, TN can be caused by a blood vessel pressing on the trigeminal nerve as it exits the brain stem. This compression causes the wearing away or damage to the protective coating around the nerve (the myelin sheath). Injury to the trigeminal nerve may also produce neuropathic facial pain. In some cases, more than one nerve branch can be affected by the disorder. While TN symptoms are most typically isolated to one side of the face, both sides of the face may be affected at different times in rare instances, or even more rarely at the same time (called bilateral TN). It is worth noting that there is no evidence that TN is psychogenic in origin or caused by depression.
Evaluation and Diagnosis
A patient’s history, physical examination, neurological examination, and even reflex testing will all assist in diagnosing TN and determining which branches of the trigeminal nerve may be affected. A 2012 case study evaluated the effectiveness of medical imaging methods such as CT, angiography, and particularly magnetic resonance imaging (MRI) to identify a vein or artery that compresses the trigeminal nerve. This study concluded that in a vast majority of cases no structural lesion causing TN is detected; however, MRI showed the most promise as it helped locate the cause of symptoms in almost 15% of cases. An MRI scan can also be used to rule out a tumor, multiple sclerosis, or other non-traumatic conditions as the cause of the pain.
Treatment options for TN can include medicines, surgery, and complementary/alternative approaches. Anti-seizure medicines aimed at blocking nerve firing can be effective in treating certain types of TN. Anti-depressants can be used to curb pain levels. Common analgesics and opioids may also be prescribed to lessen the sharp painful symptoms of TN. If medication fails to resolve the patient’s pain or produces intolerable side effects, then surgical treatment may be warranted. Surgery may become an option if the patient’s pain is intractable and medications are no longer effective in medically managing the TN condition. Several neurosurgical procedures are used to treat TN, depending on the nature of the pain, including a rhizotomy (rhizolysis) – a procedure in which nerve fibers are burned and damaged to block pain. Finally, despite the absence of clinical studies on the matter, some TN patients do experience relief with complementary/alternative treatments such as acupuncture, chiropractic and massage therapy focused on cranial-sacral approaches, biofeedback, vitamin therapy, nutritional therapy, and electrical stimulation of nerves.
One 2012 study evaluated a series of 63 patients with post-traumatic TN, with a goal of identifying its underlying causes, symptoms, and the factors that influence TN recovery. This study concluded trauma plays a significant role in TN with close to 40% of all cases involving trauma. The researchers concluded that 40% of patients with trigeminal neuropathy achieved significant symptom reduction in the first 6 months when treated with varying courses of medications. 51% of the study’s participants reported significant decline in symptoms up to one year after injury. Patients over 60 years of age reported the most significant pain, combined with increased pain associated to sensory defects caused by their TN. There were no correlations between patient gender and the characteristics, frequency or duration of their pain.
TN attacks can stop for a period of time, then return. The condition can be progressive, with fewer and shorter pain-free periods before they recur. Eventually, the pain-free periods can disappear and medication to control the pain can become less effective. Due to the intensity of the pain, some individuals may avoid daily activities or social contacts because they fear an impending attack. The attorneys at Adler ♦ Giersch, PS understand the medical-legal and insurance complications associated with complex traumatic personal injury conditions such as TN. In particular, patients suspected of TN will require a thorough medical evaluation from providers specializing in this condition along with legal counsel to determine the connection between their condition, their trauma, and coverage of treatment by the responsible insurer(s). If your patient needs a legal consultation, simply have them give us a call at 206.682.0300.