Samobathi Pain Clinic

All about Pain Management



Trigeminal Neuralgia





Trigeminal Neuralgia is a disease causing intense facial pain. The pain is characterized by sharp electric shock like feeling in one side of the face along the distribution of one or more division of trigeminal nerve. The attacks are short lasting i.e. seconds to minutes. Sometimes there may be successive attacks.

The attacks may be triggered by speaking, chewing , touching the area. In severe cases even blow of air on the affected side of face may be painful.




TRIGEMINAL NEURALGIA





INTRODUCTION



The first Description of a disease like trigeminal neuralgia we get from the writings of Ibn Sina (980-1073) in an arabic text. The first attempt to treat trigeminal neuralgia was done by John Locke in 1677, who applied sulphuric acid to the face to treat trigeminal neuralgia' Trigeminal neuralgia successfully treated for the first time by alcohol injection by Pitres in 1902. First RF lesioning for this ganglion was described by Sweet and Vepsic in 1965, First Retro-gasserian glycerol injection was done by Hakanson in 1981. Percutaneous balloon compression was performed by Mullan and Lichtor in 1978 for the first time.



SYMPTOMS OF TRIGEMINAL NEURALGIA





The main symptom of trigeminal neuralgia is unilateral facial pain and the character typically described as agonizing, paroxysmal and lancinating in one or more divisions of trigeminal nerve namely V1 - Ophthalmic Division V2 Maxillary Division and V3 is the mandibular division. Activities like chewing, speaking, touching the face at the affected side may trigger the attacks. Trigeminal Neuralgia may be of two types the first one is idiopathic and the other is secondary to other diseases like CP angle tumor or Multiple Sclerosis. Trigeminal neuralgia secondary to multiple sclerosis may be bilateral.



EPIDEMIOLOGY OF TRIGEMINAL NEURALGIA





Trigeminal neuralgia is more common in females. The male :female ratio is 2:3. The peak incidence is in between 50 and 70 years. If we see the division wise distribution the most common is the involvement of V2+V3 division (32%), the next common is isolated maxillary(V2) division and involving all 3 divisions (V1+V2+V3) of trigeminal nerve (17% each). Next common is the involvement of isolated mandibular(V3) division at (15%) patients. Follows the V1+v2 at 14% cases. Isolated ophthalmic division involvement is the rarest at 4%



PATHOPHYSIOLOGY OF TRIGEMINAL NEURALGIA





Pathophysiology of idiopathic trigeminal neuralgia still remains unknown.

One of the proposed mechanism is the compression of trigeminal nerve by aberrant blood vessels at the trigeminal root, causing demyelination and ectopic impulse generation. Though it is not found in all cases of idiopathic trigeminal neuralgia.

Secondary Trigeminal neuralgia may be caused by CP Angle tumor, Multiple sclerosis or injury caused by previous surgeries.



DIAGNOSIS OF TRIGEMINAL NEURALGIA





The diagnosis of trigeminal Neuralgia in mainly based of history of the patient. The following questions are often asked to the patient. Does the pain occur in attacks? Are most of the attacks are of small duration (seconds to minutes)? Are the attacks unilateral? Do the attacks occur in the region of face? Are there unilateral autonomic symptoms? Unilateral autonomic features (like lacrimation, nasal stuffiness, conjunctival congestion, redness in one side of face ) are not found in trigeminal neuralgia. Other diseases that can mimic trigeminal neuralgia needs to be excluded as well. They are Temporo-Mandibular Joint (TMJ) Arthritis, Persistent Idiopathic Facial Pain, Sphenopalatine neuralgia, Migraine, Dental Disorders etc. Neurological Examination of all cranial nerve needs to be done carefully. In idiopathic trigeminal neuralgia they are normal, in secondary trigeminal neuralgia the features suggestive of CP Angle tumor or Multiple sclerosis may be found.



Medical management of trigeminal neuralgia





The drug of choice for trigeminal neuralgia is carbamezepine. The starting dose 100-200 mg in divided dosage, and gradually to be increased to 400-800 mg\day depending of response and adverse effects.

The best alternative to carbamazepine is Oxcarbazepine usually started at a dose of 150 to 300 mg , the dose is gradually increased to 900-180

The other alternative is Gabapentin -900- 2400 mg/day, Phenytoin – 300-500mg/day

Baclofen ( 5 mg orally 3 times a day for 3 days, then 10 mg orally 3 times a day for 3 days, then 15 mg orally 3 times a day for 3 days, then 20 mg orally 3 times a day. Maintenance dose: 40-80 mg/day. 80 mg/day doses should be administered in 4 divided doses.)

N.B.: Drugs to be taken under strict medical supervision and the required blood investigations to be done as per recommendation of individual medications



Short Clinical Practice Algorithm





Patients suspected having trigeminal neuralgia with Intense paroxysmal unilateral facial pain from history, are subjected to through clinical examination. MRI Scanning of brain is recommended for ruling out other disorders and identifying aberrant vessels if present. Medical Management is usually recommended first with medicines. If the medical managements fail or patients are unable to tolerate the medicines due to adverse effects, patients are selected for interventional or surgical management. MVD is the treatment of choice in young patients, whereas for older patients Percutaneous Radiofrequency Lesioning around the Gasserian Ganglion is treatment of Choice.



Interventional treatment options of trigeminal neuralgia



Percutaneous Glycerol Rhizolysis



This is the simplest technique in which 50- 90 % glycerol in injected at trigeminal ganglion. The average duration of pain relief is 6 months to 1 year. The procedure can be repeated. Foraminal Fibrosis may occur by repeated injection.



Percutaneous Radiofrequency (RF) Rhizolysis



This is the treatment of choice for trigeminal neuralgia in aged and can also be done in young individual. The pain relief period is much longer compared to other techniques. This procedure may be done as day care procedure.



Percutaneous Balloon Micro-Compression



In this technique 4 Fr Fogarty catheter is inserted through 14G, 10 cm needle. The balloon is kept inflated there for 60 seconds to 120 seconds to selectively block a delta and c fibers. Pain relief period is 2- 74 months in different studies,



Stereotactic Radiation Therapy (Gamma knife)



Stereotactic Radiation Therapy is one of the non-invasive treatment for trigeminal neuralgia. Pain, Pain relief is not immediate, it takes around 3 months for onset. Only one third of patients gets complete pain relief. Number of studies is still limited regarding efficacy though the procedure is safe.



Trigeminal Ganglion Cryotherapy



A comparatively newer mode of neurolysis, Showing good results in trigeminal neuralgia.



Gassarian Ganglion Stimulation. (Experimental)



Trigeminal Ganglion Stimulation can be tried when other modalities are not effective.



Surgical Microvascular Decompression



Microvascular Decompression is a surgical technique in which the ganglion is separated from the aberrant vessel with sponge after doing craniotomy.