What is Trigeminal Neuralgia?
This is a chronic form of pain condition that affects the trigeminal nerve. The trigeminal nerve is the fifth cranial nerve that arises from the brain to the face. It transmits pain and burning sensation from forehand, midface, and chin to the brain. Any kind of pain or pressure on the trigeminal nerve may lead to the trigeminal neuralgia, however, the exact cause is not known.
This cranial nerve has 3 main branches :
Ophthalmic division - This division supplies the scalp, forehead, upper part of the sinus, upper eyelid, cornea of the eye and bridge of the nose.
Maxillary division - This division transmits sensory information to lower eyelid, the middle part of the sinus, nasal cavity and middle part of the nose, cheeks, upper lip, and roof of the mouth.
Mandibular division - This branch affects the outer part of the ear, the lower part of the mouth, tongue, lower lip and chin.
There is extreme sharp pain which may get stimulated while teeth brushing, shaving while applying makeup, eating, drinking, or even while speaking. The pain occurs in the form of spasm that feels like an electric shock. Each episode may last up to a few seconds or even minutes. Such episodes may continue to occur for several days, weeks or months with periods of remission. Trigeminal Neuralgia can be worsened with time with an increase in the frequency and intensity of the attacks. The pain may also remain constant.
What can cause Trigeminal Neuralgia?
In this condition, the trigeminal nerve is either damaged or some pressure is being put on the nerve.
The nerve may experience the pressure either due to an adjacent swollen blood vessel or a tumor present in the vicinity of the nerve.
Another reason may be multiple sclerosis that causes damage to the myelin sheath. The myelin sheath is a protective layer that covers the nerves.
Aging can be another reason responsible for increased chances of trigeminal neuralgia.
Any brain lesion, surgical procedure, head trauma or injury may also be responsible for the condition.
As per the best neurosurgeons in India, the condition is more common in women than in men especially above the age of 50.
Characteristics of pain in trigeminal neuralgia
There is a severe, shooting, stabbing, or jabbing type of pain.
There may also be constant aching, burning feeling before the spasm.
The areas involved may include those supplied by one or all the branches of the nerve such as cheek, jaw, teeth, gums, tongue, lips, eyes, forehead or scalp.
It usually occurs on one side of the face. In rare cases, it may also occur on both sides.
It either occurs on one specific point or may radiate to a larger area.
A detailed medical history plays a very important role in the diagnosis of trigeminal neuralgia. The patient must inform the doctor about all the episodes and about all the triggering factors in detail. Also, it is important to tell inform the patient about any neurological disorders that have occurred before.
The medical history is followed by a physical examination in which the doctor touches different parts of the face to the which part and which division of the nerve is affected. If needed, the patient may also be advised to have MRI (Magnetic Resonance Imaging). Sometimes certain tests are ordered to rule out conditions such as cluster headaches or postherpetic neuralgia.
Antiseizure medications or anticonvulsant medications - These drugs are used to prevent a process called nerve firing. This helps in the reduction in the frequency of the episodes. These include Tegretol, Carbatrol, clonazepam, gabapentin etc.
Muscle relaxants - certain muscle relaxants such as gablofen and Lioresal are usually prescribed. There may be side effects such as confusion, drowsiness or nausea.
Botox injections - Cases in which the oral medications fail to provide relief, these botox injections containing onabotulinumtoxinA are administered.
A beam of radiation is focused on the root of the trigeminal nerve. This is used to damage the nerve and eliminate pain. Facial numbness is one of the possible side effects. This is a successful procedure in most of the cases and can be repeated if needed.
Radiofrequency thermal lesioning
In this procedure, a hollow needle is passed through the course of the nerve. Once, the affected area is located, an electrode is passed through the hollow needle to pass an electrical current. The patient will then confirm the exact location wherever he feels the tingling. Once this is done, the electrode is heated, and those particular nerve fibers are destroyed to eliminate the pain. Side effects may include temporary facial numbness or remission of pain after 3 to 4 years.
This procedure is done by relocating and removal of blood vessels that are in touch with the nerve root and preventing the function of the nerve. An incision is made behind the ear following by creating a small hole in the skull. Then any blood vessel that touches the nerve is moved from its place and a soft cushion-like substance is placed between the nerve and the vessel. There is no chance of facial numbness after the procedure.
This procedure is done under local anesthesia. A needle is inserted through the cheek into the skull base. With the help of the x-ray, the needle is approached to a small sac of spinal fluid that surrounds the root of the trigeminal nerve. Once the needle is in place, a small amount of glycerol is released, which blocks the ability of the nerve to transmit any signals of pain. This is a day-care procedure.