Pain & headache modified (GU Physical) (1).pdf

F A C U L T Y O F P h y s i c a l M e d i c i n e  Pain& Headache Dr. Asmaa Tarek Ebrahim Lecturer of physiology  Pain sensation Def: unpleasant sensation. Type: 1. According to onset & duration of pain: fast (acute) &slow (chronic). 2. According to...

F A C U L T Y O F P h y s i c a l M e d i c i n e  Pain& Headache Dr. Asmaa Tarek Ebrahim Lecturer of physiology  Pain sensation Def: unpleasant sensation. Type: 1. According to onset & duration of pain: fast (acute) &slow (chronic). 2. According to site of pain: cutaneous (skin), deep ( muscle, tendon, joint, ligament) & visceral. Receptor: Free nerve ending (nocireceptor).  Stimulus: mechanical, thermal & chemical. Mechanism of stimulation: stimulus cause tissue damage and release of chemical substances that stimulate the nociceptors. Adapation: Non adapting receptor or sensation as it is a protective sensation. Tract: Lateral spinothalamic tract.  Referred pain Def: pain felt in an area far from its origin. Examples: 1. Headache: Toothache cause referred pain to skull. 2. Appendicular pain cause referred pain to umbilicus. 3. Renal pain: Ureteric stone cause referred pain to inguinal area. 4. Cholecystitis cause referred pain to back of right shoulder and scapula. 5. Cardiac pain (angina, MI) cause referred pain to jaw, left shoulder & inner side of left arm.  Reactions of the body to pain Rule: we are all equal in sensation of pain but differ in reaction to pain. 1.Motor or somatic reactions , in the form of reflexes e.g a. cutaneous pain might cause withdrawal reflex. b. visceral pain might cause muscle contraction above the diseased area. 2. Autonomic reactions: a. cutaneous pain might cause sympathetic reaction with increase in HR & ABP. b. visceral pain might cause parasympathetic depressor effect with decrease in HR & ABP and this might lead to neurogenic shock. 3.Emotional reactions: acute pain causes crying and anxiety while chronic pain might cause depression.  Pain examination Fast Pin Prick test Slow Ischemic pain test Pin Prick test  Pin Prick test Precautions: Hold the pin between thumb and middle finger and support the head of pin by index finger. Touch the skin with vertical pin rapidly. Repeated stimulation done with equal strength.  Case 1 31-year-old male complains of pain over his forehead and cheeks which develops gradually. This pain becomes sever on bowing his head down for praying. 1. What is type of this pain? It is headache (referred pain). As headache is a painful sensation at head that is referred from other structures. 13 2. What is the differential diagnosis of this case? - Causes of headache: a.Extracranial causes: 1. Eye diseases (glaucoma, error of refraction). 2. Teeth diseases (toothache). 3. Sinusitis (retro-orbital or forehead pain). 4. Ear diseases (otitis media, otitis externa). 5. Psychogenic (tension headache due to spasm muscle of scalp). 14 b. Intracranial causes: Brain itself is insensitive to pain, but pain due to irritation, inflammation, distension of intracranial pain sensitive structures. 1. Meningeal irritation. 2. Decrease CSF pressure. 3. Distention intracranial arteries (fever, headache, migraine). 15 Case 2 20-year-old female had an accident. She lost pain sensation on the right half of her body. 1. Which tract is affected? - Left lateral spinothalamic tract. 2. Could other sensations can be affected or lost? - Yes, temperature sensation (hot & cold) could be affected if the lesion is in the lateral spinothalamic tract not in the receptor or the cortex. 16 Thank you