Nervous system Flashcards
Most common diabetic mononeuropathy
CNIII
Acute down and out with dipoplia - but can still react to light and accomodate because ps efferent are lateral and the nueuropathic infarction is central
ptosis - since CNIII also innervates levator palpebrae
cranial nerve III compression
Pupillary dysfunction often first because peripheral PS
Function of facial nerve VII
4
- Motor output to facial muscles
- PS innervation to lacrimal, submandibular, sublingual salivary glands
- Special affarent fibers for taste from ant 2/3 tongue
- Somatic affarent from the pinna and external auditory canal
Patient with Bell’s palsy presentation
unilateral facial paralysis
decreased tearing
hyperacusis
loss of taste sensation over ant 2/3 tongue
Which CN provides sensation to face?
CNV
Pass through
Optic canal
CNII
Ophthalmic artery
Central retinal vein
Pass through
superior orbital fissure
CN III, IV, V1, VI
opthalmic vein
sympathetic fibers
Pass through
foramen rotundum
CN V2
Pass through
foramen ovale
CN V3
Pass through foramen spinosum
middle meningeal
pass through internal auditory meatus
CN VII VIII
Pass through jugular foramen
CN IX
CN X
CN XI
jugular vein
pass through hypoglossal canal
CN XII
Pass through foramen magnum
spinal roots of XI
Brain stem
vertebral arteries
gall bladder and diaphragm referred pain
right shoulder via phrenic nerve receives referred pain
where synthesis epinephrine
pons - locus ceruleus
synthesis dopamin
relevant conditions
substantia nigra and ventral tegmentum
up in Huntingtons
down in Parkinsons and depresssion
synethsis serotonin
raphe nuclei in pons/midbrain/medulla
Acetylcholine synthesis and conditions
basal nucleus of Maynart
up in Parkinsons
down in Alzheimer’s and Huntingtons
GABA synthesis and conditions
Nucleus accumbens
down in Huntingtons and anxiety
how does glucose and aa get in brain?
carrier mediated transport to cross bbb
sleep wave order
BATSDB Beta - awake eye open Alpha - awake eye closed Theta - 1 Sigma - 2 Delta -3 Beta - Rem
VPL of thalamus
in - spinothalamic
to - 1ssc
VML of thalamus
in - trigeminal and gust
to- 1ssc
LGN of thalamus
vision to calacrine
MGN of thalamus
hearing to auditory cortex of temporal
VL thalamus
basal ganglia / cerebellus to motor cortex
Hemiballismus
caused most frequently by a contralateral lacunar stroke in the subthalamic nucleus
intracellular inclusions in parkinson
lewy bodies -
alpha-synuclein (eosinophilic)
atrophy seen in Huntingtons
caudate atrophy
nueronal death in huntingtons via
NMDA-R binding and glutamate toxicity
lesion to non-dominant parietal-temporal cortex
hemispatial neglect
lesion to dominant parietal-temporal cortex
agraphia / acalculia / finger agnosia / left-right disorientation (Gerstmann syndrome)
agnosia
to interpret sensations / recognize things
Mammilary body lesion
Wernicke Korsakoff confusion ophthalmoplegia ataxia memory loss confabulation
cerebellar hemisphere lesion
limb ataxia
fall towarad side of lesion
balance problems
cerebellar central vermis lesion
truncal ataxia
subthalamic nucleus lesion
hemiballismus contralaterally
paramedian pontine recticular formation lesion
eyes look away from side of lesion
frontal eye field lesion
eyes look toward lesion
How does gaba-a receptor work?
chloride channel - open –> inhibition
How do benzos work
modulate GABA-A - increase the frequency of chloride channel opening
Diphenhydramine
sedating antihistimine - rerversibly blocks H1 receptors
in addition to their anxyloytic effects, what other effects to benzos have?
also have muscle relaxant and anti-convulsant effects - in addition to anxiolytic
inhibit norepinephrine and serotonin reuptake
TCADs
what makes the moa of barbiturates different from benzos
barbiturates stablizes the chloride channel (GABA-Ar) in the open position and have a longer half life
benzo increase the frequency that it is open
amino acid serotonin is synthesized from?
tryptophan
how does ondansetron work?
5HT3 receptor antagonist
useful to treat visceral nausea due to infection, chemo, distention
irritated mucosa releases 5HT3 which stimulates vagal affarents to activate the medullary vomiting center
when would we give antihistamine or anticholinergics for nausea
vestibular nausea
Metoclopramide
dopamine receptor antagonist
effective in treating central nausea (migraine)
adverse - extrapyramidal / sedation
Prochlorperazine
Dopamine receptor antagonist for central nausea
Loperamide
mu-opiod receptor agonist for diarrhea - antimotility agent
diphenhydramine
1st gen antihistamine -
can be used to treat vestibular nausea - can cause sedation
meclizine
first gen antihistimaine
scopolamine
muscarinic antagonist - can be used to treat vestibular nausea
causes sedation
promethazine
dopamine and h1 receptor antagonist - rx for vestibular nausea
can cause sedation
ranitidine
H2 blocker - reduces gastric acid secretion - GERD
Octreotide
somatostatin receptor agonist - inhibits bioactive amine release - used to treat diarrhea in carcinoid syndrome and VIPomas
ALSO FOR ACUTE ESOPHAGEAL VARICES
5-HT3 receptor antagonist for visceral nausea
ondansetron
common causes of travelers’ diarrhea
E Coli (bacteria)
Rotavirus
Cryptosporidium (aids)
classic finding in uncal herniation
blown pupil (dilated) due to ipsilateral oculomotor nerve palsy
Synthetic steroid that used to be used to treat endometeriosis that can cause idiopathic intracranial hypertension?
danazol
Rx for idiopathic intracranial htn?
acetozolamide (carbonic anhydrase inhibitor)
topiramate (carbonic anhydrase inhibitor and apparent antiepileptic)
3 signs of normal pressure hydrocephalus
wet
wobbly
wacky
incontinence
ataxia
cognitive dysfunction
Cushing’s triad for increased intracranial pressure
hypertention
bradycardia
bradyypnia
as uncal herniation progresses, you may see a fixed dilated pupil at first due to ipsilateral oculomotor nerve palsy, but what will happen as the hernia progresses?
progression results in damage to the mid-brain, which will result in fixed pupils bilaterally. Additional findings in advanced herniation include loss of vestibular ocular reflex and decorticate - above red nucleus (flexural) followed by deceburiate - below red nucleus (extensoral) posturing
trigeminal nueralgia first line therapy?
Carbamazepine - a neuroleptic medications (partial) - that reduces firing by reducing the ability of sodium channels to recover from inactivation
side effects of carbamazepine
bone marrow suppression - pancytopenia :(
SIADH
Benztropine or Trihexyphenidyl
anti-muscarininc (central) that can help with extrapyramidal signs of anti-psychotics D2 blockers
dantrolene
direct acting skeletal muscle relaxant for neuroleptic malignant syndrome
Serotonin syndrome
characterized by
restlessness altered mental status hyperreflexia clonus diaphoresis tremors
TMP/SMX fetal consequences?
Neural tube defects
which antibiotics can cause neural tube defects?
TMP/SMX which is you think about it makes sense because they are dihydrofolate reductase inhibitors? or something along those lines… and we see neural tube defects in folate deficient madres
which drugs can lead to impaired fetal renal function and cause fetal anuria and oligohydramnios?
NSAIDs
Woudl you give a pregnant women acetomenophin
no! it is an NSAID and NSAIDs are toxic to tots
Some baby you are taking care of is yawning, sweating, and irritable with tremors - what do you think??
Maybe he had in utero exposure to opioids and is now going through opioid withdrawl
classic opioid withdrawl symptom
yawning - withdrawing from?
Akathisia - and treatment?
extrapyramidal side effect of antipsychotic characterized by inner restlessness and an inability to stand in one position - - thus, increasing antipsychotic dose - as might be done if misinterpreted as worsening of symptoms - would make matters worse - give them a beta blocker or benzo
Dopamine can make you nauseous, because it stimulates the emetic center in the brainstem - so if you add carbidopa - why would this help if the brainstem is where we are?
because the emetic center is outside the blood brain barrier
If a patient comes in with all sorts of ocular dysfunctions - ptosis / mydriasis / inability to move their eye in any direction - ipslaterally - how would you differentiate between a lesion in the brainstem and a problem in the cavernous sinus?
brainstem lesions should have accompanying crossed signals - i.e. ipsilateral cranial nerve palsy with contralateral hemiparesis and signs of ataxia
what important structures pass through the IOF?
Maxillary division of V
infraorbital vessels
branches of sphenopalatine ganglion
Vernet syndrome - lesions of the jugular foramen lead to ?
CN IX X XI functions impaired dysphagia hoarseness loss of gag ipsilater uvula deviation to normal
which nerves traverse the cavernous sinus and thus would present problems in cavernous sinus syndrome?
III
IV
V (1 and 2)
VI
Can phenytoin cause gingival hyperplasia?
yes
how does phenytoin cause gingival hyperplasia?
increased expression of PDGF - Exposure of macrophages to PDGF increases their synthesis of gingival cells (thats what it said)
aspirin can cause reye which can effect the liver - light microscopy will show?
steatosis - small fat vacuoles in cytoplasm of hepatocytes
em will show swelling, decreased # mitochondria, glycogen depletion
reye syndrome first fucks with the liver but can then cause
encephalopathy - toxic effect of hyperammonemia
