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‘Pain’ is what brings most people to a neurology outpatient clinic. And the pain can be any type: headache and facial pain, acute spasmodic pain along the main sensory nerve of the face and motor nerve for the muscles of chewing (trigeminal neuralgia), neck pain, back pain, diabetic peripheral neuropathy (where the sensitivity of nerves to pain is dulled due to diabetes, particularly in the legs and feet), etc. |
Clinical Features
Pain is a common symptom, which may be related to bone and joints (arthritis, vitamin D deficiency, etc.), decreased blood supply to limbs (peripheral vascular disease), or even be neurological. Knowledge of the clinical features of nerve pain helps in correctly identifying and planning its treatment.
- In cases of Diabetic Peripheral Neuropathy (DPN), the pain is commonly located in the feet. These patients define their pain as a ‘burning, tingling, pins-and-needles’ sensation. For them, pain would be present at rest and on exertion, typically worse at night, interfering with sleep. Though patients with long-standing diabetes are more likely to develop DPN, nerve pain can even be the initial presenting symptom of diabetes. Other features of DPN may include numbness and weakness of feet, and imbalance while walking.
- Other common cause of nerve pain is lumbar disc prolapse, commonly referred to as sciatica. Pain in this condition, is commonly present in the lower back, from where it radiates to the leg either along the back or the outer aspect of the thigh, depending on the nerve that is compressed. Pain increases on coughing, sneezing or bending forward - due to a stretch effect on the nerve root. Leg pain also increases on walking - referred to as claudication.
Investigating the Cause
- Common causes for peripheral neuropathic pain include diabetes mellitus, vitamin B12 deficiency and hypothyroidism. Therefore, blood tests such as, fasting blood sugar, glucose tolerance test, and serum vitamin B12 assay and thyroid profile are done.
- Nerve conduction studies (NCV/EMG) are performed to detect the type, severity and extent of neuropathy.
- MRI of spine is done to detect disc prolapse in appropriate cases.
- A biopsy of the sural nerve (located near ankle) may be required in some cases for final confirmation of the diagnosis.
Treating the Pain
There are various medications available to treat nerve pain. Medications are started at a low dose and dose is increased on the basis of efficacy and tolerability. The drugs are safe and effective – but do not try to be your own prescribing doctor.
- Nerve blocks (using anaesthetic agents) are given in severe cases of nerve pain.
- Local ointments are also helpful in some cases.
- Surgical decompression of the nerve root is required in some cases; antidepressants, antiepileptic drugs, etc are used in such situations.
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Dr. Sudhir Kumar is Consultant Neurologist at Apollo Health City, Hyderabad |
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