LOW INTENSlTY LASER THERAPY FOR HEAD NECK AND FACIAL PAIN

Professor P.F. Bradley
University College Hospital, London, UK

Method
Employs lasers which are compact and low priced because they use diode technology. The two most frequently used modalities are:-

1. Near Infra Red Gallium Aluminum Arsenide 820nm
This is the most widely applicable wavelength due to its deep penetration in tissue.

2. Visible Red Helium Neon 632.8nm or Diode 660nm
There is evidence that red light is well absorbed by chromophores in nerve tissue and epithelium particularly, although its penetration is less than near infra red. Commonly used pulsed in acupuncture techniques.

Mechanisms of Pain Relief
There is experimental evidence for:
a) Effects on nerve: changes in sodium potassium ATPase have been reported and microneuronography has demonstrated damping action on fine non myelinated fibers.
b) Energisation of depleted enzymes e.g. super-oxide dismutase.
c) Elevation of endorphin levels have been reported after treatment of trigger zones in muscle.

Head and Neck Clinical Applications of LILT
LILT is proving useful in a wide variety of painful conditions in the Head and Neck but the following are particular applications:

1. TM Joint Pain Dysfunction
In acute conditions (less than eight weeks duration) it may be the sole treatment. In more chronic cases without bone changes on x-ray, it is a useful adjunct to other therapy e.g. splints. In osteoarthritis cases it can be as effective as intra articular steroid.

2. Post Herpetic Neuralgia
LILT has been shown to be effective in double blind cross over studies.

3. Trigeminal Neuralgia
LILT can be useful in reducing dose requirements of patients on Carbamazapine.

4. Painful Ulcerative Conditions
The inflammatory stage of the ulcer is materially shortened with concomitant pain relief.

5. Pain of Advanced Oro Facial Cancer
Initial work shows that LILT can be effective in palliative regimens and may allow reduction of opiate dosage.

References
Moore K and Calderhead R.G 1991. The clinical application of low incident power density 830nm Gallium Aluminum Arsenide diode laser radiation in the therapy of chronic intractable pain. International Journal of Opto Electronics: 6:5:503-520

Bradley P.F & Rehbini Z 1994. An evaluation of Low Intensity Laser Therapy for Temporomandibular Joint Pain. Abstracts of International Congress on Lasers in Dentistry Singapore. 106