Flashcards in Neuro Random facts Deck (109):
In the glabrous (hairless) skin, for dynamic, fine/light touch, position sense, adapt quickly
Adapt quickly, in the deep skin layers, ligaments, joints, sense vibration and pressure
Adapt slowly, in the fingertips and superficial skin, sense pressure, deep status touch (e.g., shapes, edges), position sense
Adapt slowly, in the fingertips and joints, sense pressure, slippage of objects along surface of skin, joint angles change
What are does stress and panic
locus ceruleus (where norepi is synthesized)
Vitamin necessary for synthesis and catabolism of GABA
How is GABA synthesized?
From glutamate by glutamate decarboxylase
What causes the extra ocular eye movements during REM?
Paramedian pontine reticular formation/conjugate gaze center
Pain, temp; pressure, touch, vibration, proprioception (from the spinothalamic and DCML pathways)
Face sensation, taste (from the trigeminal and gustatory pathway)
Vision (goes TO the calcarine sulcus)
What are the output nerves from the cerebellum?
Purkinje cells to the deep nuclei of cerebellum to the contralateral cortex via superior cerebellar peduncle
Characteristic lesion for hemiballismus
Contralateral subthalamic nucleus
Which disease do you see Lewy bodies in?
Neurohormonal changes in Huntington's disease?
Increased dopamine, decreased GABA, decreased ACh
What causes neuronal death in HD?
NMDA-R binding and glutamate toxicity
Agraphia, acalculia, finger agnosia, left-right disorientation
Lesion to the dominant pariental-temporal cortex, Gerstmann syndrome
Damage to the PPRF
Eyes look away from the lesion
Damage to the frontal eye fields
Eyes look toward the lesion
What is cerebral perfusion driven by?
Pco2 (hypoxemia increases cerebral perfusion only when Po2 is less than 50)
Why do people faint in panic attacks?
Hyperventilation leads to decreased cerebral perfusion
Equation for cerebral perfusion pressure
Symptoms of lateral medullary syndrome
Vomiting, vertigo, nystagmus; decreased pain and temp sensation from ipsilateral face and contralateral body; dysphagia, hoarseness, decreased gag reflex; ipsilateral Horner syndrome; ataxia, dysmetria
What blood vessel is damaged to give Wallenberg syndrome
Symptoms of AICA damage
Lateral pontine syndrome. Similar to Wallenberg but PARALYSIS of FACE as well, decreased lacrimation, salivation. (NO dysphagia or hoarseness). "Facial droop means AICA's pooped"
Lesions where causes allodynia
What is an inherited disease that could look like polio?
Spinal muscular atrophy (Werdnig-Hoffmann disease), AR
What innervates the salivary glands
Facial nerve innervates submandibular and sublingual, glossopharyngeal innervates parotid
What produces aqueous humor?
Ciliary epithelium (beta)
What innervates the dilator and sphincter muscle of the eye?
Dilator is sympathetic (alpha-1), and spinchter is parasympathetic (M3)
Vision changes in glaucoma
Progressive peripheral visual field loss
What is glaucoma?
Optic disc atrophy with characteristic cupping (thinning of outer rim of optic nerve head) usually with elevated intraocular pressure and progressive peripheral visual field loss
Cause of open angle glaucoma
Primary is unclear. Secondary can be from blocked trabecular meshwork from WBCs (e.g., uveitis), RBCs (e.g.. vitreous hemorrhage), retinal elements (e.g., retinal detachment)
Cause of primary closed/narrow angle glaucoma
Enlargement or forward movement of lens against central iris causes obstruction of normal aqueous flow through pupil resulting in fluid build up behind the iris, pushing peripheral iris against the cornea and impeding flow through the trabecular meshwork
Secondary causes of closed/narrow angle glaucoma
Hypoxia from retinal disease induces vasoproliferation in iris that contracts angle
Painful red eye, sudden vision loss, halos around lights, rock-hard eye
Acute angle-closure glaucoma
Distortion and eventual loss of central vision
Age-related macular degeneration
1. Nonproliferative- damaged capillaries leak blood->lipids and fluids seep into retina-> hemorrhages and macular edema. 2. Proliferative- chronic hypoxia results in new blood vessel formation with resultant traction on retina
Acute, painless monocular loss of vision
Central retinal artery occlusion/retinal detachment (?)
Bone spicule-shaped deposits around macula
What is retinitis pigmentosa
An inherited form of retinal degeneration. Painless, progressive vision loss beginning with night blindness (rods affected first)
What causes the ptosis in Horner's syndrome
Lack of sympathetic to the superior tarsal muscle
Fourth nerve palsy
Diplopia when trying to look down (reading or going downstairs) because eye is stuck up, tilt their head toward the opposite side of the affected eye`
Right MLF is which one
The one that connects the left CN VI nucleus to the right CN III nucleus (Directional term [ie right INO, left INO]) refers to which eye is paralyzed
Does ApoE2 increase or decrease the risk for Alzheimer's
Histology of Alzheimer's
Senile plaques in gray matter (extracellular beta-amyloid core that may causes amyloid angiopathy), and neurofibrillary tangles (intracellular hyperphosphorylated tau protein, number of tangles correlates with degree of dementia)
Histology of frontotemporal dementia
Pick bodies: silver-staining spherical tau protein aggregates
Histology of Lewy body dementia
alpha-synuclein defect (Lewy bodies, primarily cortical)
Charcot triad of MS
Scanning speech, Intention tremor (also incontinency and internuclear ophthalmoplegia, nystagmus)
How does baclofen work?
GABA-B receptor agonist
Tx for neurogenic bladder in MS
catheterization, muscarinic antagonists
Tx for Guillan barre
Respiratory support, plasmapheresis, IV immunoglobulins
AD, aka hereditary motor and sensory neuropathy, defective production of proteins involved in the structure and function of peripheral nerves or the myelin sheath, associated with scoliosis and foot deformities
AR lysosomal storage disease due to deficiency of galactocerebrosidase. Buildup of galactocerebroside and psychosine destroys myelin sheath. Findings: peripheral neuropathy, developmental delay, optic atrophy, globoid cells
AR lysosomal storage disease due to arylsulfatase A deficiency. Build-up of sulfatides causes impaired production and destruction of myelin sheath. Findings: central and peripheral demyelination with ataxia, dementia
X-linked, disruption of metabolism of very-long-chain fatty acids causing buildup in the nervous system, adrenal gland, testes. Can lead to long-term coma/death and adrenal gland crisis
What can be used for migraine prophylaxis?
Propranolol, topiramate, Ca channel blockers, amitriptyline
What does positional testing show in peripheral and central vertigo
Peripheral-delayed horizontal nystagmus; central- immediate nystagmus in any direction, may change directions
Genetics of Sturge-Weber syndrome
Congenital, non-inherited (somatic), developmental anomaly of neural crest derivatives dues to an activating mutation of GNAQ gene
STURGE: Sporadic, port-wine Stain, Tram track calcifications, Unilateral, Retardation, Glaucoma, GNAQ gene, Epilepsy
HAMARTOMAS: hamartomas, angiofibromas, mitral regurgitation, ash-leaf spots, cardiac rhabdomyoma, tubers, autosomal dOminant, mental retardation, renal Angiomyolipoma, Seizures, Shagreen patches
Features in vHL disease
Hemangioblastomas (high vascularity with hyper chromatic nuclei) in retina, brain stem, cerebellum, spine; angiomatosis (e.g., cavernous hemangiomas in skin, mucosa, organs); bilateral renal cell carcinomas; pheochromocytomas
What do meningiomas arise from?
Histology of meningioma?
Spindle cells concentrically arranged in a whorled pattern; psammoma bodies (laminated calcifications)
What can hemangioblastomas produce?
Erythropoietin (so can cause secondary polycythemia)
What do Scwannomas stain positive for?
Histology of schwannoma
Spindle cells with palisading nuclei arranged around Verocay bodies and composed of eosinophilic cores (Antoni A pattern) and mixed regions of low cellularity (Antoni B)
Round nuclei with clear cytoplasm
"Fried egg" cells of an oligodendroglioma. May also see calcifications and "chicken wire" capillary pattern
Pilocytic astrocytoma (in children), optic glioma in an adult
Rod-shaed blepharoplasts found near nucleus
Ependymoma. Blepharoplasts=basal ciliary bodies
Which alpha agonists can be used in glaucoma?
Epinephrine and brimonidine, both decrease aqueous humor synthesis. Do not use epic in closed-angle glaucoma because it causes mydriasis
Which beta-blockers are used in glaucoma?
Timolol, betaxolol, carteolol
MOA of pilocarpine, carbachol, physostigmine, and echothiphate in glaucoma
Increased outflow of aqueous humor via contraction of ciliary muscle and opening of trabecular meshwork
What do you use for glaucoma in an emergency
Which prostaglandins can you use in glaucoma and what are their side effects?
Latanoprost and travoprost, SE: darkens color of iris
How do opioid analgesics work?
Act at opioid G-protein coupled receptors. Open K channels and close Ca channels, decreasing synaptic transmission. Inhibit the release of Ach, norepi, 5-HT, glutamate, and substance P.
MOA of tramadol
Very weak opioid agonist, also inhibits 5-HT and norepi reuptake
MOA of ethosuximide
Blocks thalamic T-type Ca channels
MOA of phenytoin
Increases sodium channel activation; zero-order kinetics
MOA of gabapentin
Primarily inhibits high-voltage-activated Ca channels; designed as a GABA analog
First line for seizures in neonates
Which anti-epileptic causes kidney stones?
What is vigabatrin used for?
Infantile spasms (West syndrome), but ACTH is a better treatment
First line for simple and complex partial seizures
Drugs with low solubility in the blood have what type of induction
Drugs with high solubility in lipids have what type of potency
Cause of malignant hyperthermia
Due to abnormal ryanodine receptors on the surface of the sarcoplasmic reticulum releasing large amounts of calcium after exposure to an anesthetic
Why is thiopental so short acting?
Rapid redistribution into tissue
MOA of arylcyclohexylamines
(Ketamine) PCP analogs that act as dissociative anesthetics. Block NMDA receptors.
MOA of propofol
Order of nerve blockades from local anesthetics
Small myelinated -> small unmyelinated -> large myelinated -> large unmyelinated. Order of loss: pain, temp, touch, pressure
MOA of local anesthetics
Block Na channels by binding to specific receptors on inner portion of channel. Preferentially bind to activated Na channels, so most effective in rapidly firing neurons
Reversal of blockade for non-depolarizing neuromuscular agents
Neostigmine (must be given with atropine to prevent muscarinic effects such as bradycardia)
Drugs for Parkinsons
BALSA: bromocriptine, amantadine, levodopa (with carbidopa), selegiline (and COMT inhibitors), antimuscarinics
MOA of pramipexole, ropinirole
MOA of amantadine in Parkinsons
Increases dopamine release and decreases dopamine reuptake
Toxicity of amantadine
Ataxia, livedo reticularis
Use of benztropine in Parkinsons
Antimuscarinis, improves tremor and rigidity but has little effect on bradykinesia
Drugs used for Alzheimers
Memantine (NMDA receptor antagonist); helps prevent excitotoxicity (mediated by Ca); AChE inhibitores- donepezil, galantine, rivastigmine, tacrine
MOA of sumatriptans
5-HT-1B/1D agonists. Inhibit trigeminal nerve activation; prevent vasoactive peptide release; induce vasoconstriction