What is the natural history of trigeminal neuralgia? The average duration of pain for a first episode is 49 days, though the range is from 1 day to 4 years. 65% of people who have one episode will go on to experience a recurrence within 5 years.

Like most types of neuropathic pain, anticonvulsants are the first line therapy for the treatment of trigeminal neuralgia. Carbamazepine (Tegretol) is the gold standard, with a number needed to treat of 2.5. The dose is started low and quickly titrated up to as much as 2400 mg daily. For patients who do not tolerate carbamazepine or who need an add-on therapy, pregabalin is an option.

Which patients require an MRI? Although some would argue that all patients with pain in the territory of the trigeminal nerve should have an MRI, others argue that this study is needed only for those with atypical symptoms, younger age groups, or people who fail to respond to treatment.

The attacks are stereotyped in the individual patient, which means the patient experiences the same symptoms every time.

Pain has at least one of the following characteristics:

Paroxysmal attacks of pain lasting from a fraction of a second to two minutes, affecting one or two divisions of the trigeminal nerve.

The diagnosis of classical trigeminal neuralgia is made based on clinical history and a focused physical exam. The International Headache Society has established diagnostic criteria.

10-20% of patients have a slightly different condition which is referred to as painful trigeminal neuropathy. In these cases, instead of vascular compression, the nerve is compressed by other lesions, such as cysts, tumors. Multiple sclerosis may also be a cause. These patients experience persistent pain in between attacks and have positive findings on neurologic exam, like facial weakness or absent corneal reflexes.

Classical trigeminal neuralgia accounts for 80-90% of cases. It is caused by vascular compression of the trigeminal nerve root. The superior cerebellar artery is the usual culprit. The compression results in demyelination and misfiring of the nerve, which gives the clinical picture of stabbing paroxysms of pain. This condition is also called Tic Douloureux (translation: painful tic).

Norma’s story:

Norma is a retired nurse who developed excruciating pain in her left nostril after blowing her nose. She felt like she had a hole in her nostril, as if there were cold air going into it. That pain continued for months.

The pain changed and became more severe, though not yet debilitating. She sought medical attention and was started on medications for suspected trigeminal neuralgia. Carbamazepine was started at 100 mg bid and gradually increased to 1200 mg daily.

The pain escalated despite a higher dose of carbamazepine; Norma was unable to talk, eat, drink, or move her mouth without triggering excruciating, lightning-sharp pain. Initially, the pain would come on randomly, so she couldn’t prepare for it. Later, the pain was constant. It caused Norma to panic. A neurologist suggested adding pregabalin (Lyrica), 225 mg daily, and symptoms improved.

Initially, Norma’s trigeminal neuralgia involved only nerve root V1. Later, it spread to V2 and V3.

Norma developed side effects to her medications. While on only carbamazepine, she experienced drowsiness. After escalating the dose of carbamazepine and adding pregabalin, she developed ataxia and diplopia.

Norma was referred to a neurosurgeon because of ongoing pain and underwent three surgical procedures. The first surgery was a microvascular decompression of the superior cerebellar artery which was initially successful, and Norma was able to taper off of all medications. But the pain returned on August 23rd of the next year, triggered by brushing her teeth. She had to resume carbamazepine and had a second microvascular decompression, which yielded only 6 months of pain relief. Gamma knife radiation was her third surgery, and after a short period of relief, the pain returned in a peculiar way. Following radiation treatment, Norma only had pain first thing in the morning and at night; during the day, she was pain-free. She resumed carbamazepine and pregabalin, at mid-range dosages.

Norma and Heidi considered numerous alternative therapies, including botox, topical lidocaine, topical capsaicin, tizanidine, acupuncture, peripheral nerve blocks, and proparacaine eye drops. When her pain was most severe, she was prescribed opioid therapy for pain and lorazepam for panic. A Cochrane review of non-antiepileptic medications found that there is insufficient evidence to show benefit from these remedies.

Zhang J, et al. Non-antiepileptic drugs for trigeminal neuralgia. Cochrane Database Syst Rev. 2013 Dec 3;12:CD004029. PMID: 24297506.

Although Norma did not have long-lasting relief with microvascular decompression, many patients have long-lasting effects, if not permanent improvement. A Cochrane review of the neurosurgical interventions for classical trigeminal neuralgia concluded that there is currently insufficient scientific data to support the efficacy of any particular neurosurgical treatment.