Neurology Flashcards
MELAS def and inheritance pattern
mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes-seizure with stroke like episodes with residual neurological defect, muscle weakness, increased serum lactate levels both post exercise and at rest.
name three clinically important mitochondrial diseases and inheritance.
Liber hereditary optic neuropathy-leads to bilateral vision loss
Myoclonic epilepsy with ragged-red fibers- myoclonic seizures and myopathy associated with exercise. (MERRF) skeletal muscle biopsy shows irregularly shaped muscle fibers (ragged red)
Mitochondrial encephaomyopathy with lactic acidosis and stroke-like episodes
-inheritance is maternal
listeriosis causes (2) in which pt population (2) is transmitted how? grows well where? morphology?
sepsis and meningitis-immunocompromised host
neonatal meningitis
transmitted through foods (milk products, undercooked meats, and unwashed raw veggies)
-grows well in cold temps (can contaminate cold food)
-gram positive rod with V or L formations (like corynebacterium)-“tumbling motility”
lateral geniculate nucleus vs optic tract lesion
both produce contralateral homonymous hemianopia but optic tract also produces a Marcus Gunn pupil (APD).
optic tract because nasal portion contributes more input to pretectal nucleus than the temporal portion of retina. swinging flashlight test (from unaffected to affected) shows pupils appearing to dilate b/c they constrict less than when light is shown in the unaffected eye
T-tubules are found in what cell type? location? function?
in striated muscle cells. junction of A and I bands, tubular network open to extracellular space and facilitates spread of depolarization to the inside of the cell
keratin vs kinesin
keratin is found in desmosomes (aka macula adherens) which provide structural support b/t cells.
kinesin is MT associated motor protein that mediates anterograde (towards + end) transport
do microvilli have microtubules?
no! they cover the apical plasma membrane (i.e. intestinal epithelial cells) and contain actin thin filaments
depressed pt develops HTN after a wine and cheese party is on what type of drug?
monoamine oxidase inhibitor (MAO inhbiitor)-phenelzine
inhibitors:
presynaptic selective serotonin uptake
presynaptic selective norepinephrine uptake
presynaptic non-selective monoamine uptake
enzymatic monoamine degeneration
- SSRIs (serotonin)
- bupropion (NE), FA says dopamine too?
- TCAs/SNRIs (NE or Serotonin)
- MAO- non selective (phelenzine) and selective (selegiline-MAO-B, increase Dopamine in Parkinson’s)
denial vs fantasy
denial-doesn’t acknowledge truth
fantasy-acknowledges truth but substitutes a less disturbing version of reality
which has better side effect prolife TCAs or SSRIs
SSRIs- sexual dysfunction
TCAs urinary retention (anticholinergic effect), cardiac arrhythmias (prolongs QRS and QT interval), seizures (clomipramine, antihistamine,antimuscarinic, anesthetic properties), orthostatic HTN (anti-alpha adrenergic effect), sedation (anti-histamine effect)
two mechanisms of polyhydraminos
impaired swallowing (GI atresia (obstructions) or anencephaly) or increased fetal urination (high CO due to anemia or twin to twin transfusion syndrome- twins share placenta unequal blood flow between them)
chronically progressive pre-senile demnetia with cortical atrophy but no radiological or laboratory abnormality
Alzheimer’s (AD)- diagnosis of exclusion.
decreased Ach
therapies- donepezil (cholinesterase inhibitor), antioxidants (vitamine E-alpha-tocopherol), and memantine (NMDA receptor antagonists-prevents exitotoxcity; mediated by glutamate increasing Ca2+ levels)
avoid-benzos (b/c of anti-depressive effects) can be used to treat associated anxiety and insomnia though
name 3 categories of benzodiazepines:
- risk of fall
- risk of dependence
three classes are short acting (<10 hrs), medium (10-20hrs) and long (days)
- longer acting are more likely to have day time somnolence and increased risk of falls and short acting do not
- longer acting are less likely to cause physical dependence and short acting are
examples
short-alprazolam, triazolam, oxazepam (use in elderly)
medium-estazolam, lorazepam, and temazepam
long- chloridiazepoxide, clorazepate, diazepam, flurazepam* (avoid in elderly)
mutations associated with Alzheimer’s
early onset
late onset
early onset: APP (21), presenilin 1 and presenilin-2
late onset: apolipoprotein E4
common conditions associated with Downs
Acute Leukemias (AML/ALL) Congenital heart Disease (endocardial cushin defects, VSd, and ASD) Gastrointestinal Defects:duodenal atresia and Hirschsprung disease
negri bodies
round eosinohpilic inclusion seen in cytoplasm of pyramidal neurons and cerebellar Purkenje cells; rabies virus
how do the terminal sulcus and foramen cecum relate to the tongue innervation regions
terminal sulcus delineates the anterior 2/3 of the tongue from the posterior 1/3.
the foramen cecum is located along terminal sulcus at the midline
which prokaryotic DNA polymerases have proof reading activity? which direction?
which one can proof read in the other direction?
how is it’s repair different from the other polmerases?
all three have proof reading activity and can remove mismatched nucleotides in 3’ to 5’ exonuclease activity
DNA polymerase I has 5’ to 3’ activity and can excise and replace RNA primers and damaged DNA sequences.
lesion in brain that can cause alexia without agraphia
splenium of corpus callosum
mechanism of opiod agonist. give major example of one
bind to mu receptors (GPCRs that activate second messengers resulting in increased K+ efflux and decreased Ca2+ influx) blocking postsynaptic transmission of pain. morphine
describe three types of neurona response to injury and their associated histoplasmic changes
- acute neuronal injury (aka red neuron)- shrinkage of cell body, pykinosis of nucleus, loss of Nissl substance, eosinophilic cytoplasm
- axonal reaction- (loss of axon), enlargement of cell body, eccentric nucleus, enlargement of nucleolus, and dispersion of Nissl substance
- neuronal atrophy (progressive degenerative dz) loss of neurons and functional groups of neurons, reactive gliosis
therapy for acute mania
mood stabilizing agent (lithium, valproate, or carbamezapine) plus an atypical antipsychotic (olanzapine)
treatment of essential tremors. inheritance pattern
non specific beta-blockers (i.e propanolol) autosomal dominant (aka familial tremor)