Of all the symptoms known pain is the most distressing and one of the reason why an individual seeks medical aid. Of all types of pain, Neuropathic pain is considered one of the most distressing. Neuropathic pain forms a major chunk of the patients seeking aid in the pain and palliative clinics..
Neuropathic pain is basically abnormal unpleasant sensation secondary to partial or total injury or disease to the nerves. There are a multitude of reasons for neuropathic pain of which 10 common causes are discussed.
Peripheral Neuropathy
These are common types of neuropathic pain characterized by burning/ electrical sensation in the hands and feet and may be associated with sensory loss and paraesthesia. Feet more commonly affected than hands. Pain is symmetrical, slow onset, progressive and ascending type. There is no associated neck or back pain.
Common causes include uncontrolled diabetes, HIV, certain medications, chemotherapy, B12 deficiency and idiopathic. Treat underlying cause. Antiseizure and anti depressant medications can help.
Radicular Pain Down the Legs or Arms
Shooting type of pain caused due to spinal nerve root irritation. The pain radiates alone the path of the nerve. The most common cause is a disc prolapse which irritates the nerve and produce symptoms. Irritation can be due to direct mechanical irritation or due to inflammatory reaction caused by the prolapsed material. Prolonged irritation and decreasing blood supply makes this nerves hypersensitive producing prolonged radicular pain.
Treatment include epidural steroid injection, medications( anti seizure,anti depressants, opioids), physical therapy, and surgery in refractory cases.
Carpel Tunnel Syndrome
Most common cause of pain in the hand. Caused due to compression of median nerve under the transverse carpel ligament in the region of the wrist. Atrophy of hand muscles can occur in severe cases. It is diagnosed by a nerve conduction study.
Trigeminal Neuralgia
Most severe form of neuropthic pain. Sometimes so severe that it can cause even suicide. Produces severe sharp electric pain involving only one side of the face. Pain is precipitated even by mild sensory stimuli like fast moving air. Treatment include medicines like carbamazepine, pregabalin, baclofen opioids etc. Trigeminal nerve block in severe pain. Surgery can be tried to tackle any abnormal vessels.
Alcohol-induced Neuropathy
People who drink too much may start to feel pain and tingling in their limbs. This is known as alcoholic neuropathy. Thiamine, folate, niacin, vitamins B6 and B12, and vitamin E are all needed for proper nerve function. Drinking too much can alter levels of these nutrients and alters nerve function.
Treatment is to stop drinking, which can help restore your nutritional health.
Post Herpetic Neuralgia
It presents as burning pain across the chest or abdomen following an outbreak of herpes zostes. The Herpes zoster virus harbours in the dorsal root ganglion that is re-activated causing burning pain, tingling or electric sensation and itching alone the nerve distribution usually thoracic dermatome. Aggressive treatment during the acute outbreak can prevent the progression to PHN. Antiseizures and antidepressants also useful.
Dr Arun Oommen
The author is consultant neurosurgeon at Lakeshore Hospital and Research Centre, Kochi