Seminar on neuralgia by sharad chand, Refer note for 4rth Pharm D students

Basics and easy concepts of neuralgia with required explainations.

1. SEMINAR ON NEURALGIA Presented by : Sharad chand Pharm D 4rth year

2. Neuralgia It is a type of pain disorder. Neuralgia is pain that follows the path of a nerve . It is a severe pain disorder of nerve in term of its distribution due to its irritation or damage.

3. Causes Certain drugs Chemical irritation Diabetes Pressure on nerves by nearby structures (for instance, tumors) Swelling and irritation (inflammation) Trauma (including surgery ) Various infections.

4. Symptoms Pain, or muscle weakness due to motor nerve damage Increased sensitivity of the skin or numbness Pain along the path of a specific nerve

5. Signs and tests Abnormal sensation in the skin Loss of deep tendon reflexes Loss of muscle mass Lack of sweating (sweating is controlled by nerves) Tenderness along a nerve, Trigger points (areas where even a slight touch triggers pain)

6. Complications Complications of surgery Disability caused by pain Side effects of medications used to control pain Unnecessary dental procedures .

7. classification Atypical (trigeminal): Post herpetic neuralgia: Glossopharyngeal neuralgia: Occipital neuralgia:

8. Trigeminal neuralgia Trigeminal neuralgia is severe spastic, lancinating facial pain due to a disorder of the 5th cranial nerve.

9. Pathophysiology Trigeminal neuralgia caused by compression of the trigeminal nerve entry to the brain stem by aberrant loops of the cerebeller arteries .

10. risk factors Multiple sclerosis Pressure on the trigeminal nerve from a swollen blood vessel or tumor

11. Symptoms PAIN DURING THE Brushing teeth Chewing Drinking Eating Lightly touching the face Shaving

12. Signs and tests Blood tests MRI of the head Trigeminal reflex testing

13. GOALS OF THE THERAPY. Reversing or controlling the cause of neuralgia(if identified) Providing pain relief Individualizing the treatment

14. Management Carbamazepine 1200mg, Phenytoin,Gabapentin Muscle relaxants (baclofen, clonazepam) Tricyclic antidepressants : (amitriptyline, nortriptyline, or carbamazepine) If treatment fail then go for surgical treatment : Inject the alcohol or phenol into peripheral branch of nerve.

15. Sl No Drugs Initial Dose (mg) Maintenance Dose(mg) Maximum Daily Dose(mg) 1 Carbamazepine 100 200 qid 1200 2 Phenytoin 100 100-400 qd /bid 400 3 Lamotrigine 25 qd 25 bid 500 4 Gabapentin 300 qd 300-900 qd /bid 1200-3600 5 Pregabalin 100qd 300 600

16. Adverse effects Drowsiness, ataxia, dizziness, blurred vision, diplopia, headache, rash, dry mouth, thrombocytopenia

17. TRICYCLIC ANTIDEPRESSANTS (TCAs) Sl No DRUGS DOSE (mg) MAXIMUM DOSE (mg) 1 Amitriptyline 25 qd 150 2 Nortriptyline 25 qd 125 3 Desipramine 25 qd 150 4 Imipramine 25 qd 150

18. Adverse effects Sedation, dry mouth, blurred vision, constipation, weight gain, orthostatic hypotension, urinary hesitancy or retention, reduced gastrointestinal motility

19. Balloon Compression of Gasserian Ganglion In this treatment a small balloon catheter is introduced through the needle into the nerve in the skull base. With the patient anesthetized the balloon is briefly inflated to compress the nerve and then removed. Initial pain relief is high: 93% and pain recurrence similar to radiofrequency treatment, about 20% over a few years. Numbness in the face, unfortunately is high (72%). Infection again is a hazard.

20. Glycerol Injection Injection of glycerol into the gasserian ganglion is a simple and effective treatment. Using a brief, intravenous anesthetic a needle is introduced into the nerve in the base of the skull and a small amount of glycerol injected. The treatment only takes a few minutes. Eighty-five percent of patients achieve immediate pain relief .

21. Post herpetic neuralgia Postherpetic neuralgia  (PHN) is a neuralgia caused by the varicella zoster virus. Typically, the neuralgia is confined to a dermatomic area of the skin and follows an outbreak of herpes zoster (HZ, commonly known as  shingles ) in that same dermatomic area.

22. HERPES INFECTION.

23. Pathophysiology Postherpetic neuralgia is thought to be nerve damage caused by herpes zoster. The damage causes nerves in the affected dermatomic area of the skin to send abnormal electrical signals to the brain. These signals may convey excruciating pain, and may persist or recur for months, years or until death.

24. Risk Site of HZ involvement Lower risk - Jaw, neck, sacral, and lumbar Moderate risk - Thoracic Highest risk - Trigeminal (especially ophthalmic division), brachial plexus Severe prodromal pain (with HZ) Severe rash

25. Symptom and Signs: Symptoms: pain that continues for 3 months or more is defined as PHN. Pain is variable from discomfort to very severe and may be described as burning, stabbing, or gnawing. Signs: Sensation may be altered over involved areas, in the form of either hypersensitivity or decreased sensation.

26. Management Mild case –simple analgesia. Moderate to severe case – Anti viral agent Famciclovir Acyclovir Valaciclovir

27. Analgesia locally applied topical agents Aspirin mixed into an appropriate solvent such as diethyl ether may reduce pain. Lidocaine skin patches. Antidepresent agent amitriptyline Anticonvulsant agent gabapentin

28. Glossopharyngeal Glossopharyngeal neuralgia consists of recurring attacks of severe pain in the back of the throat, the area near the tonsils, the back of the tongue, and part of the ear. The pain is due to malfunction of the 9th cranial nerve (glossopharyngeal nerve), which moves the muscles of the throat and carries information from the throat, tonsils, and tongue to the brain.

29. Symptoms Symptoms include severe pain in areas connected to the ninth cranial nerve: Back of the nose and throat (nasopharynx) Back of the tongue Ear Throat Tonsil area Voice box (larynx)

30. Cause Blood vessels pressing on the glossopharyngeal nerve Growths at the base of the skull pressing on the glossopharyngeal nerve Tumors or infections of the throat and mouth pressing on the glossopharyngeal nerve

31. Signs and tests Blood tests (sugar level) to look for the causes of nerve damage CT scan of the head MRI of the head X-rays of the head or neck

32. Treatment The most effective drugs are antiseizure medications, such as  Carbamazepine,  Gabapentin,  Phenytoin. Some antidepressants, such as  Amitriptyline  Nortriptyline,

33. In severe cases, when pain is difficult to treat, surgery to take pressure off the glossopharyngeal nerve may be needed. Or (rhizotomy).

34. Occipital neuralgia Occipital neuralgi a , also known as C2 neuralgia, Arnold's neuralgia, is a medical condition characterized by chronic pain in the upper neck, back of the head and behind the eyes.

35. Causes Occipital neuralgia is caused by damage to these nerves. They can be damaged include trauma (usually concussive), Physical stress on the nerve, repetitious neck contraction, Flexion or extension, complications (such as  osteochondroma. One cause is vascular compression.

36. Symptom The symptom of this condition is chronic headache. The pain is commonly localized in the back of head and around or over the top of the head, sometimes up to the eyebrow or behind the eye.

37. Treatment These include local nerve block, Peripheral nerve stimulation,  Steroids  Rhizotomy,  Phenol injections,  Antidepressants such as  Amitriptyline  Nortriptyline,  Occipital Cryoneurolysis.

38. CONCLUSION. Neuralgias are chronic affliction Need constant following care Not life-threatening disorders Chances of recurrence Medication adherence Anticonvulsants and TCAs Duration of treatment.

39. References The merck manual of medical information, second home edition ,page no . 593-594. Harrison’s manual of medicine ,17 th edition,page no 1020-1024 ,Mc- Graw hill publication . Harrison’s neurology in clinical medicine, 2 nd edition ,page no 377-383. Mc- Graw hill publication.

40. Thank you