Neuro 1 Flashcards
How are anesthetics with high tissue solubility characterized by arteriovenous concentration gradients and onset of action?
large arteriovenous concentration and slower onset of action
What are the Sx associated with syringomyelia?
The syrinx damages the ventral white commisure, leading to bilateral loss of pain and temp sensation limited to the affected levels (arms and hands). Destruction of motor neurons causes flaccid paralysis and atrophy of intrinsic hand muscles.
What is an antidote to atropine OD and why is it effective?
Physostigmine - it is a tertiary amine that can inhibit acetylcholinesterase peripherally and centrally
(Neostigmine and edophonium have quaternary ammonium structures that limit CNS penetration)
What are the 5 enzymes that branched-chain alpha-ketoacid dehydrogenase (as well as pyruvate and alpha-ketoglutarate dehydrogenase) require?
Thiamien pyrophosphate Lipoate Coenzyme A FAD NAD (Tender Loving Care For Nancy)
What vitamin is involved in the transamination and decarboxylation steps in amino acid metabolism as well as heme and nuerotransmitter synthesis?
Pyridoxine (vitamin B6)
Whate are the side effects of B6 deficiency?
sideroplastic anemia and hyperhomocysteinemia
What has 5; to 3; exonuclease activity in addition to 5’ to 3’ polymerase and 3’ to 5’ exonuclease activity?
DNA polymerase I - removes RNA primer and damaged DNA
What does DNA polymerase III do?
initiates DNA replication
What enzymes in the heme biosynthetic pathway are inactivated by lead?
delta-aminolevulinate and ferrochelatase
What compounds accumulate in lead poisoning?
delta-ALA and protoporphyrin IX
What are Sx of orotic aciduria and what supplementation can improve Sx?
orotic aciduria: hypochromic megaloblastic anemia, neurologic abnormalities, growth retardation, and excretion of orotic acid in urine
-uridine supplementation improves Sx by inhibiting carbamoyl phosphate synthetase II
What is the treatment of choice for LIsteria meningitis in infants?
Ampicllin (it is not sensitive to cephalosporins)
What pharmological therapy can be used to assist in the prevention of cerebral vascular spasm following SAH?
CCBs - especialy amlodipine
What is the first line Tx for essential HTN in the outpt setting?
thiazide diuretics
What is used as a part of the Tx for increased ICP?
osmotic diuretics such as mannitol
What is an single-gene autosomal-dominant disorder d/t the mutation of the NF1 gene located on chromosome 17?
Neurofibromatosis type 1
What causes cystic degeneration of the putamen as well as damage to basal ganglia structures?
Wilson disease
What structure is located medial to the insula and lateral to the globus pallidus on coronal sections?
putamen
What structure is immediately medial to the putamen? What structure separates this from the putamen?
globus pallidus; internal capsule
What is a mixed DA and NE reuptake inhibitor used to treat depression and smoking addiction?
Bupropion
What is the mainstay therapy of acute mania?
mood stabilizing agent (i.e. lithium, valporate, or carbamazepine) + atypical antipsychotic (i.e. olanezapine)
What is a microtuble-associated, ATP-powered motor protein that facilitates the anterograde transport of NT-containing secretory vesicles down axons to the synaptic terminals?
Kinesin
What syndrome is d/t hypersensitivity of skeletal muscles to inhalation anesthetics (especially halothane) and muscle relaxant succinylcholine?
malignant hyperthermia
How does malignant hyperthermia present clinically?
fever and muscle rigidity after surgery under general anesthesia along with tachycardia, hypertension, hyperkalemia, and myoglobinemia
What is the MOA of dantrolene?
it is a muscle relaxant that acts on ryanodine receptors and prevents further release of Ca2+ inot the cytoplasm of muscle fibers in malignant hyperthermia
What is the difference between nondepolarizing and depolarizing neuromuscular blockers?
nondepolarizing neuromuscular blockers prevent acetylcholine binding to the receptor, while depolarizing blockers causes a constant stimulation of the receptor
What are 3 traditional high potency typical antipsychotics?
haloperidol, fluphenazine, pimozide
What are 2 traditional low potency typical antipsychotics?
chlorpromazine and thioridazine
What are 4 atypical antipsychotics?
clozapine, risperidone, olanzapine, and quetiapine
What can atypical antipsychotics cover that typicals cannot?
positive and negative Sx of schizophrenia
What is first line therapy for both generalized anxiety disorder and panic disorder?
selective reuptake inhibitor (SSRI) such as paroxetine
What is a short acting BZ?
triazolam - good for pts employed in mission-critical positions
What is an intermediate acting BZ?
lorazepam
What are 3 long acting BZs?
diazepam flurazepm and chlordiazepoxide
A temporary course of what drug can be used during the SSRI initiation period if there is significant increase in anxiety related Sx?
BZs
Why is the myelopathy associated wtih vitamin B12 deficiency known as subacte combined degeneration?
it refers to the degeneration of both ascending (dorsal columns) and descending (corticospinal tract) pathways
Where is the lesion in Wernicke aphasia?
superior temporal gyrus in the dominant (left) temporal lobe
What is oligohydramnios associated with?
renal agenesis
What is polyhydramnios associated wtih?
gastrointestinal obstruction (duodenal, esophageal, or intestinal atresia) and anencephaly
What two things is valproic acid indicated for?
mood stabilizer and anticonvulsant - it decreases the propagataion of abnormal APs by enhancing the inhibitory action of GABA in the CNS
-it is the DOC for myoclonic seizures and 2nd line for absence
What is the MOA of lithium?
it acts by inhibiting the cellular concentration of IP3 and is used in preventing both manic and depressive bipolar disorder
What originates from the lateral aspect of the mid-pons at the level of the middle cerebellar peduncles?
trigeminal nerve
what arises from the dorsolateral aspect of the caudal pons at the pontomedullary junction (below middle cerebellar peduncles)?
facial n.
what arises from the preolivary sulcus at the level of the rostral medulla?
hypoglossal n.
What Sx are present with infarct to anterior portion of medial pons?
dysarthria and ataxic hemiparesis
What structure is most frequently affected in pts with Wernicke encephalopathy?
mam,illary body
What is a a short-acting hypnotic med used for insomnia unrelated to BZs that has the same MOA of binding GABAa, but a much lower risk of tolerance and dependence?
Zolpidem
What are benign and slow-growing tumors arising from the arachnoid villi associated wtih psamomma bodies?
Meningiomas
Where are meningiomas most commonly found?
parasagittal region or adjacent to the lateral convexity of the hemisphere in the region of the sphenoid wing and olfactory nerve
Where do BZs exhibit their effects?
BZs bind GABAa channels to increase Cl- influx and frequency
What can cardiac arrest d/t acute MI lead to in the brain?
global cerebral ischemia
What is the first area damaged during global cerebral ischemia?
hippocampus
What areas are most volunerable to cerebral ischemia?
- pyramidal cells of hippocampus and neocortex
- Purkinje cells of cerebellum
What X-linked recessive trait is characterized by macroorchidism, large jaws, and ears?
Fragile X syndrome
What is the genetic defect of Fragile X syndrome?
increased number of trinucleotide repeats (CGG) in the FMR-1 gene located on the long arm of the X-chromosome
How does ALS present clinically?
loss of neurons in the anterior horns of the spinal cord (LMN lesion) cause muscle weakness and atrophy; demyelination of lateral corticospinal tract (UMN) leads to spasticity and hyperreflexia
What presents with an abundance of lipids seen in the cytoplasm after ischemic infarct ~3-5 day after onset?
microglia d/t extensive phagocytosis of myelin breakdown products
What is scotoma?
any visual defect surrounded by a relatively unimpaired field of vision
What is most likely seen on visual field examination with macular degeneration?
central scotomas
What visual defect can occur d/t calcified carotid arteries?
binasal hemianopsia - pressure to the lateral areas of optic chiasm
