Neuralgias occur due to altered sensations in the nerves.
It may be due to
Ageing
Damage to nerves
Diabetes
Multiple sclerosis
Infections such as Shingles
Cancer
There are three main types of neuralgia
Post Herpetic Neuralgia (PHN)
Trigeminal Neuralgia
Glossopharyngeal Neuralgia
Post Herpetic Neuralgia
Herpes Zoster infection
This is caused by the virus which causes chicken pox (Varicella Zoster). Following a chicken pox infection the virus can stay dormant (inactive) in a ganglion of a nerve in the human body. These viruses can get activated at times i.e. in old age, immune deficiency situations and during infections after a long time. The virus starts multiplying and spreads along a nerve. As a result the infection is limited to a distribution of a nerve and you don’t get blisters all over the body but along a nerve root. Infection is called Herpes Zoster and the pain arising from that is called post herpetic neuralgia. The commonest areas of infection are the trunk and the face. Following the infection extreme pain along the nerve can be a feature. Not all will develop pain, but those who develop pain can be very unfortunate as it could last forever in some cases. I have developed heroes zoster in my 20s but was lucky enough not to develop post herpetic neuralgia.
Trigeminal Neuralgia
This is due to an increased sensitivity in one of the branches of the Trigeminal nerve. Trigeminal nerve is the 5th cranial nerve arising from the brain supplying the face. There are three branches of the nerve.
Ophthalmic, Maxillary and Mandibular. The pain can be excruciating. It can be suicidal.
Pain is increased with exposure to the cold and the wind. Treatment is challenging. Commonly the pain is caused by pressure exerted on the nerve from a blood vessel.
Glossopharyngeal Neuralgia
This is uncommon. Symptoms are pain in the throat and neck.
Trigeminal nerves distribution. Yellow is the area supplied by the Ophthalmic branch, Pink is the area supplied by the Maxillary branch and blue is the area supplied by the Mandibular branch. All branches arise from the Trigeminal nerve.
Diagnosis
By history and examination.
Treatment of Neuralgia
Better control of blood sugar in diabetics
Physical therapy
Nerve blocks such as Intercostal nerve blocks in PHN and
Trigeminal ganglion block in Trigeminal neuralgia.
Surgery as in Trigeminal neuralgia
Medications
A variety of medications are available including topical applications
for PHN such as Lidocaine patches and Capscaisin ointment.
Antidepressants – Amitriptyline, Nortriptyline, Dothiepin
AntiepilecticsPregablin, Carbamazepine, Gabapentin
Simple and Strong analgesics
There is no cure for neuralgia. Medications and interventions can
help the pain. It can settle down with time.
Dr NAMAL SENASINGHE MBBS, FFARCS, Dip in pain med,
FFPMCA,CCST (UK), Consultant in Pain Medicine
London Pain Clinic 31, Horton Place Colombo 07, Sri Lanka
Tel - 0767155716 (Hot Line)