Flashcards in Neuro from codebook Deck (50):
Sympathetic nervous system neurotransmitters
Huge narwhal/vast majority of sympathetic ANS (SANS) postganglionic neurons release norepinephrine. Colline sweating profusely + hair on end/sweat glands + piloerector muscles are an exception (postganglionics secrete acetylcholine). This is why botulinium toxin is used to treat hyperhidrosis because it blocks Ach release from sympathetic cholinergic neurons.
arcuate nucleus secretes...
Giant legolas from lord of the rings + firing a joint + he has huge balls/arcuate nucleus = secretion of dopamine (inhibits prolactin) + GH-releasing hormone + gonadotropin-releasing hormone.
Waiting line is enclosed by roman aqueducts + bode miller inside of it + pregnant woman in labor + bag of nazi thighs hanging from above + /paraventricular = ADH + CRH + oxytocin + TRH secretion.
Two huge eys on a pole outside: squirting milk + bode miller crawling out/supraoptic = secretion of ADH & oxytocin.
cells most susceptible to global cerebral ischemia
pyramidal cells of the hippocampus and neocortex + purkinje cells of the cerebellum
other signs of bilateral ACA occlusion
next to the leg, put a women pissing into the longitudinal fissures /patients with bilateral ACA occlusion can also develop significant behavioral symptoms (eg, abulia) + urinary incontinence (due to damage to the frontal micturition center).
Cauda equina syndrome
o Code: Uncle Walt: /typically results from a massive rupture of an intervertebral disk that compresses 2 or more nerve roots of the cauda equine. Can also be caused by trauma or a space-occupying lesion. Axe in his back + on top of a saddle + he’s winking his asshole + pissing all over the saddle + axes in either achilles/presentation = low back pain radiating to one or both legs + saddle anesthesia + loss of anocutaneous reflex (anal wink) + bowel and bladder dysfunction (S3-S5 roots) + loss of ankle-jerk reflex (Achilles) with plantar flexion weakness of the feet. Horse with a big chicken on it to the left + big cone covered in hair on the right/associated with damage to S2 through S4 nerve roots.
o Location: Driveway in front of barn at Meeker’s house
Conus medullaris syndrome
o Code: Uncle Walt: Massive cone in driveway + hen nesting at botom/caused by lesions at approximately L2 usually due to disk herniation, tumors, or spinal fracture. He’s pissing and shitting everywhere + dick hanging down to floor + on top of a saddle/presentation = flaccid paralysis of the bladder and rectum + impotence + saddle (S3-S5 roots) anesthesia.
o Location: Driveway of Granmere’s house
most common site of encephalocele...
Code: Lisa with smoothed brain/lissencephaly. Wagon in back full of wills/results from defective neuronal migration resulting in a lack of brain gyri (folds) and sulci (grooves).
Location: Cowboy bar
First line treatment for dystonia...
most common focal dystonia
Other forms of dystonia
1) oculogyric crisis
2) spasmodic torticolis
3) opisthotonic crisis
dystonia due to..
Usually impaired function of basal ganglia
Code: Neurosurgeon operating on Benzi’s brain, targeting a rotating globe inside of the patient’s head + a submarine hanging over head/usually target globus pallidus internus or subthalamic nucleus (high-frequency stimulation INHIBITS firing of these nuclei).
Location: Front desk in movement disorders clinic
Progressive supranuclear palsy (PSP)
Code: Nate: Stu: his midbrain and frontal brain have been cut out of his head/form of parkinsonism resulting from neurodegeneration of the midbrain + frontal subcortical white matter. Stu walking across the room + falling on the floor + eyes looking down to the floor + business executive by window/presentation = rapidly progressive gait dysfunction and falls + executive function loss + vertical gaze palsy (inability to move eyes up, called Parinaud syndrome). He’s wearing a tau robe/brain biopsy usually shows deposits of abnormally phosphorylated tau proteins.
Location: Jacquie Carrico’s apartment
Graphesthesia and etiology
- Ability to recognize writing on skin.
- caused by a lesion to the somatosensory cortex on the contralateral side.
Rules for localizing brain stem lesions...
1) cranial nerve signs will localize the lesion to the part of the brain stem affected. Midbrain (CN III or IV), upper pons (CN V), lower pons (CN VI, VII, VIII), or medulla (CN IX,X,XII).
2) cranial nerve signs will be accompanied by signs from lesions of one or more descending and ascending long tracts (corticospinal, medial lemniscus, spinothalamic, descending hypothalamics).
3) lesions to any of the long tracts EXCEPT the desending hypothalamic fibers will result in a contralateral lesion. A unilateral lesion to descending hypothalamic fibers will cause an Ipsilateral Horner syndrome.
• Intraparenchymal hemorrhage (AKA acute hypertensive intracerebral hemorrhage)
o Code: fibrinoid grim reaper showering + Abby carroll + pink membranes all around shower/pathophys chronic hypertension arteriolar hyalinization + fibrinoid necrosis weakened vessel walls Charcot-Bouchard aneurysms aneurysmal rupture can lead to hemorrhaging. Stew in a capsule on closer right + gang covered in basil plants on the roof/can occur anywhere but most cases involve the basal ganglia + internal capsule. Roman aqueduct surrounding building covered in blood/often massive and can dissect through brain parenchyma into the ventricular system (bleeding into ventricular system). Uncal walt with braces headgear on the left/very dangerous because massive hemorrhage causes mass effect transtentorial (uncal) herniation tonsillar herniation death. /thus controlling hypertension critical to preventing. Bright rays of light eminating from building/acute bleeding appears as hyperattenuated (bright) lesions on noncontrast head CT.
o Location: Shower room at AK fishing lodge
Most common cause of death from stroke?
Internal capsule stroke & other UMN lesions
Code: Stu. Space capsule covering bathroom/internal capsule stroke. Half his body covered in darts/presentation = pure motor weakness affecting contralateral arm, leg, and lower face. He’s riding a dirtbike/also presents with contralateral spasticity or hypertonia + hyperreflexia + positive Babinski sign. He’s clasping a huge butcher’s knife/can also present with “clasp-knife” spasticity (initial resistance to passive extension followed by a sudden release of resistance). /remember that UMN lesions can affect any part of corticospinal tract, including medulla, pons, midbrain, internal capsule, and precentral gyrus (primary motor cortex).
Location: by the bathrooms
1) leakage of blood into the intima-media.
2) pseudoaneurysms can erode into the vena cava, creating arteriovenous fistulas.
charcot-bouchard aneurysm presentation
progressive neurologic deficits + headache may follow
imaging note for circle of willis
note that in a view of the circle of willis you can’t see basilar or vertebrals because you’re looking up.
Basilar skull fractures
/located in vicinity of petrous bone or along sphenoid bone. /signs = hemotympanum (blood visible below tympanic membrane) + ecchymosis over mastoid processs (battle sign) + periorbital ecchymosis (“raccoon sign”). /CSF leakage (sometimes from nose) or pneumocephalus may also occur.
SAH on CT
Bright white areas in the center and along sulk.
o Code: Old lady I did the neuro exam on and cave behind her/lacunar infarct. /result from occlusion of the small penetrating arteries that supply deep brain structures. She has a diabetes pump + BP cough around her neck/usually in setting of chronic uncontrolled HTN + diabetes mellitus. Walls are pink + really fat engorged david macks behind her/pathophys = lipohyalinosis (leakage of plasma proteins through damaged endothelium leading to hyaline thickening of vascular wall + sclerosis) + microatheromas (result from atherosclerotic accumulation of lipid-laden macrophages within intimal layer). /lipohyalinosis + microatheromas predispose to small-vessel occlusion. Her right arm is flayling wildly/hemiballismus is common due to subthalamic nucleus damage.
o Location: Rose
hypertensive encephalopathy presentation
/presentation = progressive headache + nausea/vomiting followed by non-localizing neurologic symptoms (eg, confusion).
There’s a rhino behind him poking his ass with his horn + tennis court covered in spines (corticospinal code)/anterior horn and lateral column degeneration with gliosis (thus, neuronal loss in corticospinal tracts).
Other finding in tabes dorsals...
sensory ataxia leading to wide-based, slapping gait.
most cases are asymptomatic
/polio virus has been mostly eradicated due to vaccination efforts in the 20th century but many of its sequel are still being felt in patients with post-polio syndrome. /lag of several decades. /presentation = progressive weakness + motor atrophy due to continuing damage to motor units in the ventral horn.
abnormality of the gene that normally turns off perinatal programmed cell death. As a result, neuronal cell death continues postnatally and results in denervation of muscle with atrophy.
Werdnig-Hoffman other findings in imaging + presentation
1) fibrillation potentials on ECG
2) bulbar dysfunction causes poor sucking, reduced swallowing, and respiratory failure
corticobulbar pathway function
- connects cortex to brainstem primarily involved in carrying motor function of non-oculomotor cranial nerves.
- one of the pyramidal tracts, other being CS tract.
What is the impact of trinucleotide repeat expansions?
because it involves insertion of 3 nucleotides, it does not change the reading frame of the resulting mRNA. Instead it results in addition of more residues of the encoded amino acid when mRNA is translated. /results from DNA replication error during S-phase due to slippage of the polymerase during replication.
other findings in cavernous sinus syndrome
variable ophthalmoplegia + decreased corneal sensation + horner syndrome + decreased maxillary sensation + papilledema + retinal hemorrhages + cranial nerve palsies + fever + exopthalmos.
What does cavernous sinus contain?
Nerve synapsing on a brain on top of the cave + hambones stuck to cave + cave covered in hair + max with a top hat on + max in a nest + hash blocks on either side (cranial nerve generic code)/cavernous sinus contains cranial nerves III + IV + V1 + V2 + VI + internal carotid artery
other findings in 3rd nerve palsy
1) inability to abduct the eye from the abducted position (this is a function of the superior rectus).
2) Eyes on his forehead, directly horizontal to normal eyes/horizontal diplopia (lesions of oculomotor, abducens, or trochlear can cause diplopia (any muscle that innervates extraocular muscles)).
What mediates patellar reflex?
femoral nerve, which innervates muscles of anterior compartment of the thigh
Spindle afferents attached to intrafusal fibers detect changes in length of muscle by detecting tension of intrafusal fibers. /this is the reflex involved when tapping patellar tendon,e etc. (muscle is stretched, increased length detected by spindle afferents, which synapse with and activate alpha motor neurons that innervate the muscle). /hyperreflexia is a sign that upper motor neuron pathways that normally inhibit activity have been lost, thus allowing excessive response to movement.
o Code: /3 stages: 1) internal anal sphincter relaxes 2) external anal sphincter contracts 3) conscious urge to defecate is perceived. Jon Planer walking on plank dug into internal anal sphincter/controlled by pelvic splanchnic nerves (provides PS imput to internal anal sphincter (composed of smooth muscle) and carries sensory afferent information from rectum to spinal cord). Bowl of pudding stuck in external anal sphincter/pudendal nerve carries somatic efferents to external anal sphincter.
o Location: Bathroom at home
underlying underlying cause of presbyopia
Denaturation of structural proteins within the lens, which impairs lens elasticity
Arcuate scotoma etiology
occur due to damage to a particular region of the optic nerve head. /visual field defect follows the arcuate shape of the nerve fiber pattern.
ethnic groups at increased risk of angle-closure glaucoma
Inuits and asians
Marcus Gunn findings
shine light into normal eye pupil constricts fully. Shine light into Marcus Gunn pupil pupils do not constrict fully. Shine light in affected pupil again apparent dilation of both pupils because the stimulus carried by the optic nerve (CN II) of the affected eye is weaker than the normal eye. They appear to dilate; they are not dilating but are constricting to a lesser degree as compared to when light is directed to the normal eye because the pupillary light reflex is diminished in the affected eye.
neuroendocrine findings in horner's
absence of norepinephrine
other endocrine finding in AD
presenilin 1 on chromosome