FACIAL NEUROPATHOLOGY

1. FACIAL NEUROPATHOLOGY OROFACIAL PAIN

3. NOCICEPTORS:1-5MM DIAMETER NERVE FIBERS.

4. A-DELTA: Responsible for temperature and fast or first pain. Is myelinated Conduction velocity is 12-45 m/sec C-FIBERS: Responsible for slow or second pain, and temperature. Is unmyelinated Conduction velocity is 0.2-2.0 m/sec PAIN FIBERS(PERIPHERAL NERVE FIBERS)

5. TYPES OF CUTANEOUS PAIN • 1. Pricking pain, which is felt rapidly. It is felt that pricking pain is mediated by A-delta fibers. A fibers also conduct touch,warmth, and cold • 2. Dull, aching sometimes burning pain, which is mediated by C fibers. C fibers also conduct itch, warmth, and cold

6. THE TRIGEMINAL SYSTEM • Sensory input from the face and mouth is carried by V. • Cell bodies of the trigeminal afferent neurons are located in the gasserian ganglion • Impulses carried by V enter directly into brainstem(pons) and synapse in the trigeminal spinal tract nucleus

7. SPINAL TRACT NUCLEUS • Divided into 3 parts: A. the subnucleus oralis-significant for association with oral pain mechanisms B. the subnucleus interpolaris C. the subnucleus caudalis-predominates in trigeminal nociception

9. PRIMARY NEUROTRANSMITTERS FOR PAIN TRANSMISSION Glutamate, the amino acid Substance P, the peptide

10. TISSUE INJURY:causes K+, bradykinin and arachidonic acid release

11. Release of Substance P cause release of histamine and serotonin(5HT), and more bradykinin

12. Release of substance P, histamine, serotonin initiate more nociception

13. PAIN EXPERIENCE • Involves the psychologic (past experiences, cultural behaviors and emotional state) and • Physiologic aspects(involves the transduction,transmission and modulation of pain) • The experience of pain is linked to emotional,behavioral, and cognitive phenomena

14. EVALUATION OF MAXILLOFACIAL PAINSENSORY DYSFUNCTION • Obtain a chief complaint and include onset, clinical course since onset, intensity and location • Ask for assessment by the pt for objective/subjective descriptors i.e. is dysfunction intermittent/continuous; character of pain; does it occur in relation to other functions; precipitants or reliever of sxs; associated sxs etc

16. Numb Tingling Wet Rubbery Stretched Swollen Crawling Itching Prickling Electric Tender Painful Burning DESCRIPTORS OF ALTERED SENSATION

17. EVALUATE CRANIAL NERVES

18. INSPECTION / EXAMINATION • Skin changes in color or texture • Atrophic changes • Iatrogenic induced trauma • Decreased/altered taste, difficulty in chewing • Difficulty in speaking or facial animation

20. AXIS I (PHYSICAL CONDITIONS) • Cutaneous and mucogingival pains • Mucosal pains of the pharynx, nose, and paranasal sinuses • Pains of the musculoskel. Structures of the mouth/face • Pains of the visceral structures of mouth/face • Pains of the neural structures of mouth/face

21. AXIS II (PSYCHOLOGIC CONDITIONS) • Anxiety disorders • Mood disorders • Somatoform disorders • Other conditions, such as psychologic factors affecting a medical condition PSYCHOLOGIC INTENSIFICATION OF PAIN

23. FACIAL NEURALGIAS • Trigeminal Neuralgia • Glossopharyngeal Neuralgia • Geniculate Neuralgia • Superior Laryngeal Neuralgia • Occipital Neuralgia

24. NEURALGIA: Defined as paroxysmal, intermittent pain confined to specific nerve branches

25. Characterized by severe recurrent episodic attacks of unilateral pain distributed over a branch or, after many years, more than one branch of V. Associated with trigger zones Incidence per 100,000: 2.7 men and 5.0 for women Pain usu. in V-2 or V-3 in 60% of pts. More often on Rt side of body 70% of pts over the age of 50 TRIGEMINAL NEURALGIA

26. No sensory/motor loss Compression or distortion of the nerve root by an aberrant arterial loop 2-4% of cases of TN have MS TX: 1.AED’s: Gabapentin,baclo- fen,lamotrigine,carbamazepine,oxcarbamazepine 2.SURG:Radiofrequency thermolysis, Microvascular nerve root decompression,Gam- ma knife radiation TRIGEMINAL NEURALGIA

27. VASOGLOSSOPHARYNGEAL NEURALGIA • Rarer than trigeminal neuralgia • Charac. by unilateral paroxysmal stabbing pain in the posterior 1/3 of the tongue, pharynx,larynx, and soft palate. Cranial nn IX & X involved • Pain assd. with trigger zone, talking and swallowing usual stimulus • Bradycardia, hypoten., and syncope seen from activation of X • Tx: tegretol or phenytoin, topical anesthesia of pharyngeal mucosa

28. POST-ZOSTER NEURALGIARAMSAY HUNT SYNDROME • Herpes zoster is a self-limiting dz • M=F in frequency; 65% over age 70n • Syndrome arises from geniculate gangliositis. This results in a)facial paralysis, b)loss of taste of anterior 2/3 of tongue , c)loss of lacrimation, d)vesicular eruption of the external ear and e)severe pain in EAC

29. RAMSAY HUNT CON,T • Pain in the ear is severe and paroxysmal • Pain persists for weeks to years after eruption disappears • Herpes zoster (shingles) is the consequence of reactivation of the latent varicella-zoster(also causes chickenpox) virus.

30. POSTHERPETIC NEURALGIA-TRIGEMINAL GANGLIA • Similar syndrome as Ramsay Hunt except inflammation of the trigeminal ganglion by herpes zoster. • The dermatomal distribution is now associated with V-1, V-2, or V-3, and is associated with viral reactivation • 10-15% of cases, reactivation is in the ophthalmic division (ophthalmic zoster)

31. POST HERPETIC NEURALGIA • TX:Acyclovir, famciclovir, or valaciclovir. Result in more rapid resolution of cutaneous lesions and decreased viral shedding. Famciclovir associated with accelerated resolution of postherpetic neuralgia

32. SUPERIOR LARYNGEAL NEURALGIA • The superior laryngeal nerve is a br. of the Vagus, innervates the cricothyroid muscle. Will see periodic, unilateral submandibular pain radiating through eye, ear, and shoulder. Similar to IX neuralgia • Provoked by swallow/turn of the head/sneezing/yawning/nose blowing

33. OCCIPITAL NEURALGIA • The greater occipital nerve is a continuation of the C2 nerve and innervates the posterior scalp. • Will feel paroxysmal pain in posterior occipital region and cervical region

34. ATYPICAL FACIAL PAIN • Usually is a dx. of exclusion • Pain does not follow anatomic distribution of the Trigeminal nerve, crosses the midline and not limited to sensory distribution of a single nerve • More common than trigeminal neuralgia • 4th-5th decade; F>M; classified as a)psychogenic b)organic c)indeterminate

36. HEADACHES • Types: 1) Tension a)episodic or b)chronic. The chronic type may have a duration of 5 years or longer in 75% of pts. Tx with antidepressants(tricyclic)or NSAIADs 2)Vascular a)Migraines:paroxysmal headache lasting 24-72 hrs, usually unilateral. Frequency variable and aura or prodrome may precede

37. HEADACHES CON’T • 2-a) Migraines con’t: 80% of pts with family history. In childhood M>F, but after menarche F>M. Tx with compression of temporal artery, cold compress, biofeedback,narcotics. 2-b: Cluster also called Horton’s headache. 8X more common in men. May see family aggregation. Last from 15 min to 2 hrs but may occur 5-10x a day, periorbital in location and unilateral. Tx:Lithium, O2, intranasal lidocaine spray

40. HEADACHE CON’T • 3)Temporal arteritis, is an inflammation of medium- and large-sized arteries. Usually involves a branch of the carotid artery, but is a systemic dz, and may involve arteries in multiple locations. Occurs over the age of 55, F>M, and associated with polymyalgia rheumatica. Complex of fever,anemia, high ESR and HA. Tx with steroids.

42. TRAUMATIC NERVE INJURIES

43. NERVE INJURIES-CAUSATION • Inferior alveolar: Fractures of mandible, BSSO, 3rd molar removal, resection of mand.,preprosthetic surgery, implant- nerve repositioning procedures • Lingual: 3rd molar removal, resection, salivary gl. Removal, fracture and repair of mand. Angle fxs

44. NERVE INJURY CLASSIFICATION • Seddon: neuropraxia, axonotmesis, and neurotmesis • Sunderland: 1st through 5th degree

45. PATIENT EXAMINATION

46. PATIENT EXAM CON’T

47. PATIENT EXAM CON’T

48. MAPPING

49. PIN PRESSURE NOCICEPTION

50. THERMAL DISCRIMINATION