The Gasserian Ganglion can be partially ablated as it sits in Meckles Cave either by using Glycerol or by making a radiofrequency lesion.
A small thin needle is inserted into the middle of the cheek under local anaesthesia, and gently guided with X-ray assistance through the foramen ovale into Meckles Cave where the Gasserian Ganglion sits.
It is important to treat the correct branch of the trigeminal nerve involved in the pain, to avoid excessive numbness post-procedure. With latest RF generators we can stimulate to confirm the branch which is to be ablated. This improves the effectiveness of the therapy
For patients where surgery and anaesthesia is too risky, Injection Techniques may offer pain relief.
Trigeminal neuralgia (TN)
Trigeminal is 5th cranial nerve. It supplies face unilaterally through three divisions; ophthalmic, maxillary & mandibular. It never crosses midline. Trigeminal Neuralgia is the classic neuropathic pain syndrome
Clinical features:
It is a severe, almost exclusively unilateral, neuropathic pain located within distribution of trigeminal nerve ,i.e. the eyes, lips, nose, scalp, forehead, and jaw. It manifests as paroxysmal high-intensity stabbing pain lasting seconds. Each attack maybe followed by a refractory period, a period of relief that lasts seconds, minutes, or even hours.
To describe the pain sensation, patients may describe a trigger area on the face, so sensitive that touching or even air currents can trigger an episode of pain. It affects lifestyle as it can be triggered by common activities in a patient's daily life, such as eating, talking, shaving and toothbrushing. Pain attacks typically worsen in frequency or severity over time. A great deal of patients develop the pain in one branch, then over years the pain will travel through the other nerve branches. The diagnosis of trigeminal neuralgia is made from the clinical history. No medical testing is available to confirm the diagnosis; however response to carbamazepine is considered as diagnostic by some.
Medical management:
This aimed at providing rapid & sustainable pain relief with least amount of side effects. Antiepileptic drug Carbamazepine is the drug of choice. If it is not tolerated, other medications used like baclofen, gabapentin, oxcarbazepine, pregabalin, clonazepam. Etc. Many people find relief with medication.
Intervention:
Interventions are considered for those who failed medical treatment or unable to tolerate side effects.
Radiofrequency trigeminal (retrogasserian) rhizotomy is used to treat intractable trigeminal neuralgia. It may selectively destroy the unmyelinated or poorly myelinated nociceprtive nerve fibers & spares the myelinated fibers that serve touch, proprioception and motor function. Baloon decompression, percutaneous glycerol rhizotomy or surgical options named microvascular decompression (MVD) can be done.