Saturday, September 26, 2009
Trigeminal Neuralgia and Upper Cervical
Yet another example of Upper Cervical Care and the results possible.
Chiropractic management of trigeminal neuralgia: A preliminary study
Roger Hinson, DC and Susan Brown, PhD, DC.
Trigeminal Neuralgia (TN), the most common pain disorder of the face and one of the most painful afflictions known,1 affects one or more branches of the fifth cranial nerve and has a reported annual incidence of 4.3 per 100,000.2 Once known as the suicide disease, TN effects women more often than men and the annual incidence rate increases significantly with age. The pain, abrupt in onset and typically lasting no more than a few seconds, can be triggered by both mechanical and thermal stimuli from inside or outside the area of pain. TN may undergo spontaneous remissions and recurrences, but the frequency of pain commonly increases with chronicity. 3
Medical management starts with a course of anticonvulsants (carbamazepine, gabapentin, phenytoin) gradually increasing in dosage as symptoms warrant. Surgery is performed if symptoms are initially, or become, refractory to medication. Percutaneous ablation of the Gasserian ganglion is the most commonly practiced approach but carries a relatively high risk of numbness and dysesthesia. Microvascular decompression (MVD) of the trigeminal root, involving open surgery through the posterior fossa, has the best results with long term pain relief and the lowest chance of numbness and dysesthesia but greater incidence of serious complications. All currently practiced neurosurgical procedures are associated with significant morbidity and recurrence rates.
There is no reference in the indexed literature to the efficacy of chiropractic procedures for TN. We report outcomes of an 8 week trial of chiropractic care on 8 subjects suffering from TN.
Eight subjects were recruited for this study through a support organization for facial pain sufferers. All reported with a previous diagnosis made by a neurologist of trigeminal neuralgia. Seven subjects met diagnostic criteria for trigeminal neuralgia set forth by the International Headache Society (IHS), while one subject (5) described pain more characteristic of atypical trigeminal neuralgia (ATN) as there were no pain free periods and Aslow@ pain, i.e. aching, burning sensations, was more bothersome than brief, lancinating pain. One subject (7) suffered from trigeminal neuralgia and contralateral anesthesia dolorosa (AD), an iatrogenic disorder caused by surgical deafferentation and characterized by a constant sensation of numbness and burning pain. She had suffered from bilateral TN prior to unilateral radio frequency ablation two years previous.
All subjects were under medical therapy at the time of enrollment and five had undergone unsuccessful surgical treatment, four subjects had undergone two procedures and one had undergone a single procedure. All were female and the ages ranged from 47 to 79 (mean, 62; SD 11.6) years. Chronicity of TN symptoms ranged from 1 15 (mean, 7.4; SD 5.3) years.
Informed consent was obtained from all subjects prior to enrollment. (Upper Cervical)Chiropractic management was per Grostic technique protocol, which utilizes three mutually orthogonal x ray views for measuring upper cervical displacement from a theoretical norm. Adjustments were administered by one clinician as indicated by supine leg length estimation and dual probe thermocouple analysis. The adjustments consisted of a low force, precisely vectored impulse delivered to the transverse process of C1 with an instrument. Patients were seen three times per week for the first 2 weeks of care, then twice a week for weeks 3 and 4. Visits were scheduled for weeks 5 through 8 as needed, typically once a week.
Pain was assessed via short form McGill Pain Questionnaire (SF MPQ), VAS and pain drawing. Depression was evaluated with the Modified Zung Depression Index. The Rand SF 36 was used to evaluate quality of life. Questionnaires were administered at two weeks prior to (Upper Cervical) chiropractic care, on the first day of care, and after 4 and 8 weeks of care. Subjects maintained a diary in which number, intensity and duration of paroxysms and analgesic usage were recorded.
Reduction in pain was reported by all subjects during the experimental phase. Mean values after eight weeks of intervention were reduced by 69% for MPQ and 78% for VAS. Depression as measured by Zung was reduced by 43%. Pain drawings demonstrated reductions in distribution of pain for all patients. Antiseizure medication usage was discontinued by two, decreased by 33% by one and by 66% by one, and unchanged by four subjects during the eight week period of intervention. Two subjects reported complete absence of paroxysmal pain within four days of first adjustment and no return of paroxysms during eight weeks of intervention. One subject suffering from otalgia had no recurrence of such pain subsequent to first adjustment.
The spinal tract and nucleus of the trigeminus descend from the caudal brainstem down to the level of the second cervical vertebra. That area of the nucleus located in the cervical spine, the subnucleus caudalis (Vc), contains second order neurons receiving pain and temperature stimuli not only of trigeminal origin, but also from the facial (n intermedius), glossopharyngeal and vagus nerves, and converges with neurons in the upper cervical dorsal horn which convey equivalent stimuli from upper cervical dorsal rami.
Trigeminal, geniculate, glossopharyngeal, vagal and occipital neuralgias have been described as hyperactive dysfunction syndromes. The efficacy of antiseizure compounds in the treatment of these primary neuralgias results from the depression of exitatory mechanisms of Vc neurons.4 The venules which drain the lateral columns proximal to the dorsal horn where Vc is located operate at low pressure and have little redundancy 5. If adverse mechanical tension were transmitted to the cord via upper cervical dentate ligaments, this area would be among those earliest effected. Such tension could lead to direct mechanical compression of the descending tract of the trigeminus, which lies on the periphery of the cord adjacent to the dorsal spinocerebellar tract, or of Vc. Compression might also lead to venous stasis with resulting hypoxia and hyperexcitability of Vc. We speculate that such tension may result from displacement of the atlanto occipital and atlanto axial joints, and that correction of such displacements may result in attenuation of Vc hyperactivity.
Results from this study suggest that upper cervical chiropractic procedures may be of benefit to TN sufferers. Further study is needed to better qualify the efficacy of chiropractic procedures for TN and other primary neuralgias. A controlled trial is planed to improve the evidence base on which clinicians and patients can make decisions.
1. Goodman J. chap 14. In: Biller J, Ed. Practical Neurology. Lippencott Raven, 1997: 142 3
2. Katusic S, Williams DB, Beard CM, Bergstralh EJ, Kurland LT. Epidemiology and clinical features of idiopathic trigeminal neuralgia and glossopharyngeal neuralgia: similarities and differences, Rochester, Minnesota, 1945 1984. Neuroepidemiology 1991;10(5 6):276 81
3. Adams R, Victor M, Ropper A. Principles of Neurology, Sixth Ed. McGraw Hill 1997
4. Kondo T, Fromm GH, Sxhmidt B. Comparison of gabapentin with other antiepileptic and GABAergic drugs. Epilepsy Res 1991 Apr;8(3):226 31
5.Gillilan LA. Veins of the spinal cord. Anatomic details; suggested clinical applications. Neurology 1970 Sep;20(9):860 8