Trigeminal neuralgia, or tic doloureux, is one of the least recognized and most excruciating chronic pain conditions. Anticonvulsants have been shown to be effective, but some patients require surgical intervention to find relief from the pain.
Carol S. James, PA-C
lead physician assistant in the Department of Neurosurgery, The Johns Hopkins Hospital.
Trigeminal neuralgia, or tic doloureux, is one of the least recognized and most excruciating chronic pain conditions. In this world of scans, computerized histories, and lab tests, trigeminal neuralgia can be difficult to diagnose; it requires really listening to the patient and asking the pertinent questions to uncover the diagnosis.
Although patients tend to present in midlife, at Hopkins we have treated patients in our practice as old as 100 and as young as three years of age. Trigeminal neuralgia occurs more often in women than in men, and tends to favor the right side of the face more than the left. The pain is usually located in the V2 or V3 area of one side of the face, but it can also occur in V1, in multiple branches, or (rarely) on both sides of the face.
Patients often first experience trigeminal neuralgia as a spontaneous occurrence of sharp electrical facial pain while doing normal activities, leading many of them to assume they are dealing with a dental problem and contact their dentist for an emergency evaluation. Although some dental pathology is sometimes found (cavity, cracked tooth, etc), the pain is usually not permanently treated with dental procedures. In fact, such procedures can often make the pain worse, once the local anesthesia has worn off. Unfortunately, many patients undergo multiple extractions (sometimes to the point of becoming edentulous) in a desperate attempt to relieve this pain, and they are left without teeth and unable to have implants or dentures because of the ongoing pain.
Diagnosis: Proper history and imaging
Clinicians diagnosing a patient who presents with the symptoms of trigeminal neuralgia should obtain a careful medical history. Patients often describe their pain as intermittent (usually or often triggered) and shock-like, stabbing, or burning, and say it is the most intense pain they have ever experienced. It usually lasts for seconds, but can keep recurring, making it impossible to perform normal activities of daily living. Typical triggers include talking, eating, tooth brushing, washing the face, shaving, applying make-up, or experiencing a cool breeze or wind on the face.
The diagnosing clinician should also conduct a thorough neurological evaluation that includes a brain MRI, with and without gadolinium, with very fine cuts of the cerebellopontine angles to look at the nerve and the associated vasculature. This will also help to identify any other potential causes of pain such as multiple sclerosis, tumors, or vascular anomalies. Appropriate lab work should also be ordered to check for infections, etc.
The first step in treatment is to begin low-dose medication that can gradually be titrated to meet the pain management goals, and keep the side-effects to a minimum. The pain associated with trigeminal neuralgia can respond favorably to seizure medications, which are helpful in treating neuropathic pain. Typical medications used for this purpose are carbamazepine (Tegretol), gabapentin (Neurontin), oxcarbazepine (Trileptal), pregabalin (Lyrica), and sometimes steroids, baclofen, duloxetine (Cymbalta), or amitriptyline. If these drugs provide good pain relief with acceptable side-effects, patients may remain on medications. It is important to realize that the pain tends to have waxing and waning periods, with each exacerbation becoming more intense. Do not be misled if medications are ineffective at first, as they may need to be increased over time to match the intensifying pain.
It is important to gradually taper medications once it is clear that the patient is truly pain free. This should be done over weeks or months, depending upon the amount of medication and the length of use.
When medications are no longer sufficient, or the side effects are undesirable, it is time to consider a surgical option. Most patients are candidates for one or more of the available procedures, and it is necessary to assess the individual risk of each patient, including age, medical co-morbidities, and the patient’s desire for treatment. The most permanent surgical treatment is a microvascular decompression, which involves opening the skull and decompressing the trigeminal nerve from the adjacent blood vessels that are compressing the nerve. This is the most long-lasting surgery and includes a hospital stay of 2-3 days and several weeks of recovery at home.
Radiosurgery (Gamma Knife and CyberKnife) procedures involve a direct beam of radiation to the brainstem where the nerve originates. They are non-invasive outpatient procedures that do not require anesthesia. Although radiosurgery allows even the most complex patients to be treated, there may be a delay of several weeks or more in obtaining pain relief, compared with more traditional surgeries, and it is not uncommon that patients will subsequently need further procedures as the nerve regenerates.
Needle procedures (glycerin and radiofrequency rhizotomies and balloon compression procedures) are very brief outpatient surgeries, done under general anesthesia. The patient will usually begin to experience pain relief in the recovery room and there is minimal post-operative discomfort. Patients may experience pain recurrences as the nerve regenerates years later, but the procedure can be repeated as often as necessary.
It is absolutely necessary to correctly identify and diagnose trigeminal neuralgia in these patients, get them on treatment that provides adequate analgesia, and reassure them that if the pain ever returns, options are available to control their pain.