nervous system Flashcards
define paresthesia
non-painful abnormal sensations such as
numbness,
tingling,
prickling,
“pins & needles”
define hyperesthesia
unpleasant hypersensitivity;
may be due to increased response or decreased threshold;
-includes both allodynia & hyperalgesia
define allodynia
painful response to a stimulus that is NOT normally painful.
Ex: clothes or sheets touching skin
- showering
- wind on the face
define hyperalgesia
- increased response to stimuli that is typically painful
(ex: increased response to a pinprick)
migraine HA:
list signs/symptoms
- unilateral moderate to severe HA
- retro/supraorbital
- throbbing/pusatile
- associated with photo- and/or phonophobia
- associated w/N&V (esp children)
- 80% without aura; 20% experience aura
- aura usu visual (scintillating scotoma; blind spots)
migraine HA:
describe population(s) most affected
pre-puberty: males=females or males > females
post-puberty: females > males
occurences usually decrease w/pregnancy and post-menopause
migraine HA:
describe abortive and preventative treatments
Medication
Acute (abortive):
- Ergotamines
- dihydroergotamine (DHE 45)
- Tryptans (5-HT1/serotonin receptor agonists)
- sumatriptan (Imatrex)
- rizatriptan (Maxalt)
- NSAIDs
- ibuprofen, etc
Prophylaxis (≥2-4 HA’s/ month):
-anti-epileptic drugs (AEDs)
- valproate
- divalproex
- topiramate
- Beta-blockers:
- propanolol, etc
cluster HA:
-s/s
- unilateral stabbing/squeezing pain
- VERY severe brief pain
- not associated w/N&V or aura
- facial flushing, ipsilateral eye tearing, conjunctival injection, nasal congestion/rhinorrhea , Horner sysdrome
- think “labor ctx for the eyes” as the pain comes and goes like ctxs
- pain lasts for minutes and recurs several times per day
cluster HA-
risk factors
-risk factors: smoking, ETOH use, male sex
cluster HA:
treatments (acute & preventative)
-acute tx:
- high flow O2
- triptans
- ergotamines
preventative:
- lithium
- calcium channel blockers
tension-type HA:
s/s, cause, triggers, treatments
dull, achy, vice-like mild/mod pain
diffuse or headband location
underlying cause probably sustained ctx of occipital muscles
triggers: hunger, low bld glucose, lack of sleep, anger/stress
treatments: OTC pain relievers, non-pharm therapies: massage, accupuncture, biofeedback, etc
Name the locations and effects of Beta-adrenergic receptors
ß-1: heart:
- increased HR (+chronotropic effect)
- increased conduction velocity (+ dromotropic effect
- increased contaction force or strength (+ionotropic effect)
ß-2: smooth muscle of lungs, GI, GU
- bronchiole dilation, dec’d GI motility; dc’d labor; dec’d urine flow
ß-3: adipocytes:
- increased FA catabolism; activates uncoupling protein (increased heat production)
Define somatosensory
senses that can be felt almost everywhere through out the body, such as temperature, touch, pain, pressure, itchiness, vibration (versus senses are localized to a specialized sense organ such as taste, smell, hearing, sight)
Describe the characteristics of the 4 types of nerve fibers that transmit somatosensory information
TYPE DIAMETER MYELINATED? SENSES TRANSMITTED
A-alpha largest/fastest yes -mechanosensation, -proprioception
A-beta large/fast yes -pressure, touch, vibration
A-delta medium/fast lighty -localized, sharp pain
C smallest/slowest no -dull, achy, diffuse pain
What is another name for pseudotumor cerebri?
idiopathic intracranial hypertension
Differentiate between vertigo caused by
Benign Paroxysmal Positional Vertigo
and vertigo caused by CNS lesions
BPPV:
- latency: vertigo/nystagmus begins few seconds-60 sec after head position change
- habituation: symptoms/nystagmus stops upon repetition of maneuver
- fatigability: symptoms subside after 10-60 seconds
- nystagmus is usually horizontal
Vertigo from CNS lesion:
- no latency, no fatigability, no habituation
- nystagmus is often vertical
Name the maneuvers to diagnosis and correct BPPV
- diagnostic maneuver: Dix-Hallpike maneuver (aka Nylen-Barany test) (with pt’s head turned 45 degrees to one side, pt quickly leans back with head hanging off table by 30 degrees; nystagmus appears within a few seconds to one minute= positive test)
- Corrective maneuver: Epley (aka vestibular exercises): from the position above: pt turns head to opposite side 45 degrees, hold for 30 seconds, then pt turns on side and tilts head towards floor, then with head still turned, sit up on side of bed for ~30 seconds, with head down (chin to chest) for 30 sec. Can be repeated until symptoms stop.
What 3 structures make up the diencephalon?
- thalamus
- hypothalamus
- epithalamus (includes pineal gland, habenula)
Where do the dural venous sinuses empty?
- internal jugular veins
reversed prompt
non-painful abnormal sensations such as
numbness,
tingling,
prickling,
“pins & needles”
define paresthesia
reversed prompt
unpleasant hypersensitivity;
may be due to increased response or decreased threshold;
-includes both allodynia & hyperalgesia
define hyperesthesia
reversed prompt
painful response to a stimulus that is NOT normally painful.
Ex: clothes or sheets touching skin
- showering
- wind on the face
define allodynia
reversed prompt
- increased response to stimuli that is typically painful
(ex: increased response to a pinprick)
define hyperalgesia
reversed prompt
senses that can be felt almost everywhere through out the body, such as temperature, touch, pain, pressure, itchiness, vibration (versus senses are localized to a specialized sense organ such as taste, smell, hearing, sight)
Define somatosensory
reversed prompt
idiopathic intracranial hypertension
What is another name for pseudotumor cerebri?
reversed prompt
- thalamus
- hypothalamus
- epithalamus (includes pineal gland, habenula)
What 3 structures make up the diencephalon?
Name the 2 types of embryonic nervous tissue precursor cells (and what they become)
(and which embryonic tissue they derived from)
- derived from ectoderm
- neural stem cells –> become neurons and glia of the CNS (except for microglia which come from mesoderm –>monocytes in bone marrow)
- neural crest cells –> become neurons and glis of PNS
List the 3 embryonic developmental structures of the brain and what they become
-
prosencephalon (forebrain):
- telencephalon- becomes the cerebrum
- diencephalon- becomes epithalamus, thalamus, and hypothalamus
- mesencephalon (midbrain): becomes midbrain
- rhombencephalon (hindbrain): becomes the pons, medulla oblongata, and cerebullum
List the 3 divisions of the brain stem
- midbrain
- pons
- medulla oblongata
What 3 structures make up the diencephalon?
- epithalamus (pineal gland and habenula)
- thalamus
- hypothalamus
Where do the dural sinuses empty?
-into the internal jugular veins
What are the 2 major categories of the long tracts (neural)?
- Upper motor neurons: efferent; traveling from cortex, passing thru the brain stem (crossing to opposite sides), down to synapse with lower motor neurons
- Somatosensory- afferent, passing thru the brain stem (decussating) and synapsing in cerebral cortex
Regarding upper motor neurons:
trace the pathway of the corticospinal tract
starts in gray matter of cerebral cortex, axons pass thru brain stem, then most cross over to other side of spinal cord to synapse with lower motor neurons