SYMPTOMS AND CAUSES

SYMPTOMS

Classic TN has distinct symptoms which clearly separate it from other forms of facial pain

• Pain in short, acute bursts rather than dull, constant ache. Often described as electric shock-like in nature

• Pain is usually triggered by light touch or sensitivity to vibrations – brushing teeth, shaving, a light breeze, a soft kiss, talking etc.

• The pain has a tendency to come and go with periods of intense, sometimes totally debilitating pain, followed by complete pain-free periods of remission lasting from weeks to months or possibly longer.

• Most patients experience pain during the day while they are up and about. Generally, they are pain-free while asleep unless triggered by the touch of bed linens or changes in position.

The patient history and description of symptoms are the doctor’s major aids in confirming the diagnosis of TN. Most doctors will recommend a head/brain MRI or CAT scan along with other laboratory tests. These are conducted mainly to rule out other possible causes of the pain such as tumors, multiple sclerosis etc. There is no specific test available to confirm the diagnosis of TN.

CAUSE OF TN

There are several theories on the cause or causes of TN, but not one that is universally accepted by all medical professionals. The majority of specialists believe that the protective covering (myelin sheath) of the trigeminal nerve deteriorates allowing abnormal messages (pain) to be sent along the nerve. The main cause of this deterioration is usually due to a blood vessel pressing on the trigeminal nerve where it exits the brain stem. In a few cases, TN occurs as a result of a tumour or multiple sclerosis but these are relatively uncommon. The deterioration causes the nerve to send abnormal messages to the brain – like static in a telephone line. These abnormal signals disrupt the normal signal of the nerve and cause pain.

Some cases of facial pain are caused by the herpes virus following a case of shingles, but are more correctly identified as post-herpetic neuralgia rather than TN. This form of neuralgia is treated by other modes of treatment, usually with anti-viral medications and anti-depressant drugs which alter nerve transmission and help decrease the pain.