neuro disorders

• Pain is a ____ experience

  complex experience

  - with dynamic interactions between physical, spiritual, emotional and environmental factors
• Pain is defined as

  an unpleasant sensory and emotional experience associated with actual or potential tissue damage
• process of nociception

  1. Transduction --> Transmission--> Perception--> Modulation
• Transduction

  activation of nocieceptor (noxious stimuli) includes

  - chemical

  - mechanical

  - thermal
• chemical transduction

  bradykinin, seretonin, histamine, substance P, glutamate released by the body when there is potential harm
• mechanical transduction

  when body experiences pinching, cutting, stretching
• thermal transduction

  hot, cold
• Transmission (sends message about pain from the body to the brain)


  - Alpha delta fibers (send rapid, sharp, well localized pain sensation)

  
  

  - C fibers (slow, dull, aching or burning, poorly localized message)

  
  

  - Ab fibers (modulation) Activates inhibitory interneurons and blocks transmission of pain; which makes pain more tolerable
• perception and modulation of pain includes

  - conscious awareness

  - modulation
• conscious awareness


  reticular and limbic systems and cerebral cortex. Interpretation influenced by cultural factors and life experiences.
• modulation


  inhibitory neuromodulators (changes how much pain is felt) and endogenous opioids (natural painkillers in the body
• endogenous opioids are


  - enkephalins

  - endorphins

  - dynorphins

  - endomorphins
• endorphins


  "morphine within"--natural, opiate like neurotransmitters linked to pain control and to pleasure.

  
  

  - body's mood booster
• names of 5 classification of pain

  - nociceptive: pain during trauma

  
  

  - neuropathic

  
  

  - idiopathic: unkown origin

  
  

  - referred: feeling pain in one place but the problem is somewhere else

  
  

  - acute or chronic: short term, chronic stays around for a long time
• Neuropathic pain


  - injury or malfunction of the spinal cord/ peripheral nerves

  
  

  - burning, tingling, shooting, stinging, pins and needles sensation (paresthesia)

  
  

  - difficult to treat
• common causes of neuropathic pain

  diabetes and chemotherapy
• normal temperature


  98.6 F or 37 C
• measurement of core temperature

  - pulmonary thermistor

  - tympanic membrane

  - foley

  - rectal and oral temperature

  - infrared
• thermoregulation


  - mediated by hypothalamus

  
  

  - TSH-RH, TSH, thyroxine( T3 + T4) (metabolism)

  
  

  - circadian rhythm ( peaks about 6pm)

  
  

  - fluctuations with menstrual cycle, sharp rise just before ovulation
• mechanism of heat production

  - metabolism, muscle contraction (including shivering), chemical thermogenesis
• mechanism of heat loss

  radiation, conduction, convection, evaporation

  
  

  - decreased muscle tone, increased ventilation, administration of cool fluids
• Fever


  endogenous pyrogens (TNFa- IL-1, IL-6)
• raising body temp kills many microorganisms,


  decreases serum levels of iron, zinc, and copper (materials needed for bacterial replication)

  
  

  - increasing lysosomal breakdown and auto destruction of cells preventing viral replication. phagocytosis is enchanced
• hypothermia


  - 95 F

  - a range of cardiac dysrhythmias occur
• common cause of hypothermia

  A Fib

  - and associated with a decrease in cardiac output
• functions of sleep


  - conserve energy

  
  

  - restoration of tissues and growth

  
  

  - thermoregulation

  
  

  - regulation of emotions: not getting enough sleep causes emotional disorders like irritability, anxiety and depression

  
  

  - Neural maturation

  
  

  - memory and learning: info transfer between cerebral cortex and hippocampus
• sleep is controlled by the

  suprachiasmatic nucleus (SCN) in the hypothalamus (basically tells body when its to to sleep/ wake up)
• Sleep characteristics of infant and the elderly

  - infants sleep 16-17 hrs

  
  

  - elderly: total sleep time is decreased with longer sleep latency and poorer quality of sleep. sleep disorders increase the risk of morbidity and mortality
• changes in the eye with aging

  - cornea: increased astigmatism

  
  

  - anterior chamber: glaucoma

  
  

  - lens: decreased color vision, cataracts

  
  

  - retina: increased minimal amount of light to see an object
• Aging and changes in hearing

  -Cochlear hair cell degeneration

  -Loss of auditory neurons

  -Degeneration of conductive membrane of cochlea

  -Loss of cortical auditory neurons
• medications related to changes in hearing

  - Rapid iv injection of furosemine > electrolyte imbalance in hair cells, usually transient

  
  

  - gentamycin > auditory nerve damage
• changes in smell and taste in older adults

  - decline in sensitivity to oders (after age 80)

  
  

  - decline in olfaction -> leads to diminished appetite

  
  

  - inability to smell toxic fumes or gases

  
  

  - higher conc of flavors required to stimulate taste

  
  

  - taste may be influenced by decreased secretion of saliva
• Level of consciousness

  - arousal and awareness of self and environment

  
  

  - oriented x3: person, time and place (sleep deprived in hospital)

  
  

  - response to painful stimuli: withdraws (or swings at you appropriately) decorticate/ decerebrate posturing
• types of alterations is arousal

  - metabolic (tay sachs)

  - psychogenic

  - drug induced (pupillary response)
• Pupillary responses


  lack or pupil response to light indicated a brain stem lesion
• eye movements


  " dolls head" movement : a good thing

  "fixed" movement: a bad thing
• types of posturing and what they do

  - decorticate posturing: damage to one or both corticospinal tracts

  - decerebrate posturing: upper brain stem damage
• 3 compartments of cranial cavity

  1. brain tissue (80%)

  2. CSF (10%)

  3. blood (10%)
• intracranial pressure (ICP)


  - nonexpendable skull (as pressure builds, brain tissue is subject to serious damage)

  
  

  - icp within 1 compartment can be offset by a decreased volume in another compartment

  
  

  - compensation is limited by skull
• brain is able to compensate the most by

  compression

  - but brain compression may lead to rapid injury