Page 29 - Delaware Medical Journal - January/February 2020
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REVIEW ARTICLE
Carbamazepine, oxcarbazepine, and gabapentin are the most common medications used to treat TN, and the Carbamazepine and oxcarbazepine
work by using voltage-gated sodium channel blockers that are frequency- dependent. In studies, both medications a 50% or greater reduction of attacks.
In addition, carbamazepine can be useful in diagnosing classical TN as it is more likely to respond to the drug than secondary TN or another disease. Some of the side effects of the medications
are drowsiness, dizziness, nausea, vomiting, leukopenia, and aplastic anemia. Gabapentin is another popular medication to reduce pain in patients with TN. According to studies, 46%
of patients experienced a reduction in facial pain and two-thirds of the 46% did not experience a relapse after eight months.5 Cheshire reported that the patients in the study did not experience serious side effects from gabapentin.5
If the medications prove effective in treatment of TN, physicians will then attempt to gradually lower the dosage for the patient until the patient no longer requires any medication, if possible.
Surgical procedures for treatment of TN include microvascular decompression (MVD), glycerol rhizotomy (GR), and balloon compression (BC). These should only be considered after the patient has failed multiple trials of medications, because surgery not only carries a risk of serious complications but also entails suggest that pain recurrence is likely after several years.
MVD is a procedure where the surgeon makes an incision posterior to the ear and dissects through the dura mater to expose the trigeminal nerve. The surgeon then displaces the blood vessel that was
Figure 2. Severe pain relapse-free survival
impinging the nerve and places a tiny sponge or pledget to prevent the vessel from compressing the nerve again. The surgery has a quoted success rate
as a reduction of pain to a IIIb or less
on the Barrow Neurological Institute (BNI) scale (see Figure 3). Potential complications include stroke, hearing loss, neck pain, neck stiffness, and numbness.6 According to Rughani et
al, the risk of complications with MVD rises with age, with a .13% mortality rate in patients 65 and younger and a 1.16% mortality rate for patients 75 and older. In addition, “the risk of any in-hospital complication occurring in patients 65 years and older was 7.36% ... and 10.0% in those 75 years and older.”7
GR is a minimally invasive procedure utilized to partially damage and thus ameliorate the pain of trigeminal neuralgia. A glycerol injection is typically an outpatient procedure in which the physician inserts and then directs a needle through the foramen
ovale to where the trigeminal nerve splits into its three main branches and then injects glycerin onto the offending branch. The glycerin destroys nerve/ minutes. It has a moderate success rate, with a risk of complications including bleeding, infection, nausea, vomiting, anesthesia complications, and a small chance of numbness.
BC is another minimally invasive rhizotomy. It involves a balloon being inserted using a needle that is guided through the cheek and through the inside the skull, mechanically damaging the trigeminal nerve in order to relieve some of the pain.9
SRS is a non-invasive treatment utilizing multiple focused high-
energy radiation beams to treat a variety of brain conditions; usually malignancies, but also benign entities such as meningiomas and arteriovenous malformations. The main devices for
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