Neuro Flashcards
Sturge-Weber syndrome
Congenital, non-inherited, inactivation of GNAQ gene, development issue with NC derivatives; affects capillary (port-wine stain), ipsi leptomeningeal angioma (seizures/epilepsy/intellectual disability), episcleral hemangioma (glaucoma)
Tuberous sclerosis
Hamartomas in CNS/skin, ash-leaf spots, rhabdomyoma/MR, mental retardation/seizures, renal angiomyolipoma
Neurofibromatosis type 1
Mutated NF1 tumor suppressor gene (neurofibromin, a negative regulator of RAS) on c17; skin tumors (from NC cells), cafe-au-lait spots, lische nodules, optic gliomas
von Hippel-Lindau disase
Hemangioblastomas (high vascularity with hyperchromatic nuclei) in retina, brain stem, cerebellum, spine; angiomatosis (e.g. cavernous hemangiomas), b/l RCC, pheo
GBM
Cerebral hemisphere, crosses corpus callosum, astrocytes stain for GFAP; histo: “pseudopalisading” pleomorphic tumor cells
Meningioma
Arachnoid cells, extra-axial, and may have dural “tail;” histo: spindle cells concentrically arranged in a whorled pattern with psammoma bodies (laminated calcification)
Hemangioblastoma
Cerebellar; a.w. von Hippel-Lindau syndrome if found with retinal angioma; produces EPO - polycythemia; histo: closely arranged, thin-walled capillaries with minimal intervening parenchyma
Schwannoma
Cerebellopontine angle, often CNVIII, S-100. If b/l vestibular, suspect NF-2
Oligodendroglioma
Frontal lobes; chicken-wire capillary pattern with oligodendrocytes with fried-egg cells
Pilocytic astrocytoma
Posterior fossa, well-circumscribed, GFAP-positive, benign; histo: rosenthal fibers (eosinophilic, corkscrew fibers), cystic
Medulloblastoma
Cerebellar, highly malignant; can compress 4th ventricle and cause hydrocephalus, can “drop metastasis” into spinal cord; histo: homer-wright rosettes, small blue cells,
Ependymoma
4th ventricle, ependymal cell, cause hydrocephalus, poor prognosis; histo: characteristic perivascular rosettes, rod-shaped blepharoplasts (basal cilary bodies) near nucleus
Craniopharyngioma
Supratentorial, derived from Rathke pouch remnants, may be confused with pituitary adenoma; histo: calcifications
Cingulate herniation
Under falx cerebri; compress ACA
Transtentorial herniation
Caudal displacement of brain step, rupture of paramedian basilar artery branches, duret hemorrhages, usually fatal
Uncal herniation
Medial temporarl lobe, compresses ipsi CN III, ipsi PCA, contra crus cerebri (ipsi paresis)
Cerebellar tonsillar herniation
Compression of brain stem, coma and death
Ventral posterolateral nucleus (VPL)
spinothalamic tract (P/T), medial lemniscus (position/propprioception); primary somatosensory cortex
Ventral posteromedial nucleus (VPM)
Trigeminal, taste pathways; primary sensory cortext
Lateral geniculate body
Opitc nerve; visual cortex (calcarine sulcus)
Medial geniculate body
Superior olivary nucleus/inferior colliculus of the pons; auditory cortex of the temporal lobe
Which sense does not have a relay nucleus in the thalamus
Smell
Three DA systems, function, and related disease
Mesolimbic-mesocortical/regulates behavior/schizophrenia; nigrostriatal/coordination of voluntary movements/ Parkinsonism; tuberinfundibular/prolactin secretion/hyperproactinemia
GABA receptors types/location
GABAa: brain, ion channel; GABAb: brain, g-protein; GABAc: retina, ion channel
BZD, barbs, ETOH moa
Bind to different GABAa receptor and facilitate inhibitory action in the CNS
Craniopharyngioma
Calcified cystic mass in suprasellar region with yellow, viscous, cholesterol-filled fluid; histo: cysts lined by stratified squamous epithelium with keratin pearls; derived from Rathke’s pouch (ectoderm that develops into anterior part of the pituitary gland); pw HA, growth failure, bitemporal hemianopia
Beta-endorphin precursor
POMC, a polypeptide precusor that also produces ACTH and MSH
S-ANS usual setup and deviants
2-neuron unit that synapse on noradrenergic receptors on target organs (viscera); the innervation of adrenal glands (no 2nd neuron) and sweat glands (both neurons use ACh)
Alzheimer disease
Neurofibrillary tangles and A-beta-amyloid plaques
Neurofibromatosis Type 1
Single-gene AD mutation of NF1 gene on c17; pw cafe-au-lai spots, multiple neurofibromas, lisch nodules (pigmented asymptomatic hamartomas of iris)
Bulimia nervosa vs anorexia
Binge-eating and either restrictive or purging compensatory behaviors; different from anorexia in that pt maintains regular body weight (>17.5 BMI) and does not have amenorrhea
Neural structures and neurons: NE, ACh, DA
nucleus ceruleus (dorsal pons), nucleus basalis of Meynert, substantia nigra
PICA
Common in pregnancy, often with ice, a.w. Fe deficiency
Thalamic stroke
Total sensory loss on contralateral side; proprioception deficit may lead to ataxia
Lacunar infarcts moa, RF
Small vessel lipohyalinosis and athersclerosis involving the pentrating vessels of the deep brain structures (BG, posterior limb of internal capsule, pons, cerebellum); uncontrolled HTN and DM
Central pontine myelinolysis presentation
Spastic quadriplegia and pseudobulbar palsy
Huntington moa, presentation, histo
AD increased CAG repeats in HD gene on c4; NMDA receptors bind glutamate and die; loss of GABA neurons in caudate nucleus and putamen; progressive dementia, aggressive behavior, choreiform
Acoustic neuromas
Sensineural hearing loss, tinnitus, facial muscle paralysis, loss of corneal reflex indicate CN 5, 7, 8 involvement; located at cerebellopontine angle
Germ cell tumors
Pineal and suprasellar regions, can cause obstructive hydrocephalus (2/2 aqueductal stenosis) and parinaud syndrome (paralysis of vertical gaze)
MCA stroke
Hemiparesis (arm>leg), and if on dominant hemisphere, Broca’s aphasia
ACA stroke
Hemiparesis (leg>arm), urinary incontinence, primitive reflexes
AICA stroke
lateral inferior pontine syndrome, which is contra loss of P/T, ipsi CN 5, 7, horner’s syndrome and cerebellar syndrome
PICA stroke
Lateral medullary syndrome (Wallenberg), which is contra P/T loss, ipsi CN 5, 8, 10, 11, and horner’s syndrome
Malignant hyperthermia
Occurs in certain genetically-susceptible individuals after inhalation anesthetics or succinylcholine. Treated with dantrolene, which blocks ryanodine receptors and prevent release of Ca into SK fibers
Diabetic neuropathy 2 moa
1) hyalinization of nerve arterioles, narrowing of lumen, ischemic injury; 2) accumulation of sorbitol and fructose in nerve axons
GBS
Segmental demyelination of peripheral nerves and endoneural inflammatory infiltrate; pw ascending flaccid paralysis (esp lungs, CN 7), areflexia, albumino-cytologic disassociation
CN4 palsy
Vertical diplopia
Werdnig-Hoffman syndrome
Anterior horn cell damage, LMN lesions; flaccid weakness, areflexia, muscle atrophy, fasciculation (“floppy child” syndrome)
Thiamine deficiency
Key coenzyme in pyruvate dehydrogenase; giving glucose without thiamine will exacerate deficiency and Wernicke encephalopathy; affect the mammillary body
Inhaled anesthetics SE
Increased cerebral blood flow and ICP; other SE include myocardial depression, hypotension, respiratory depression, and decreased renal function
Cerebral amyloid angiography
Beta-amyloid deposited into arterial wall, predisposing to rupture; related to age, unrelated to systemic amyloidosis; presents with recurrent hemorrhages in cerebral areas. Smaller, less severe than HTN hemorrhages (which tend to be in BG)
Kinesin and dynein
Microtubular transport proteins; anterograde, retrograde, respectively; Dynein also functions in ciliary and flagellar movement
B12 deficiency
Anemia with subacute, combined degeneration of the posterior and lateral spinal columns; diagnosis with increased methylmalonic acid
Old infact
Cystic cavity surrounded by wall of astrocyte processes (gliosis)
Opiod SE that do not develop tolerance
Constipation and miosis
Morphine tolerance MOA
Phosphorylation of opioid receptors, increased AC activity or increased NO activity; glutamate activation of NMDA receptors enhance morphine tolerance; NMDA receptors like ketamine block the actions of glutamate and can decreased tolerance
5-HT syndrome
Neuromuscular excitation (hyperreflexia, clonus, myoclonus, rigidity, tremor), ANS stimulation (hyperthermia, taachycardia, diaphoresis, vomiting/diarrhea), AMS (agitation, confusion); can occur with single OD or with combined MAO-I; precursor is tryptophan; can treat with cyproheptadine (antihistamine with anti-serotonergic properties)
Clozapine
Acts on D4 receptors (unlike tradiational DA agaonists, which act on D2 receptors); SE: life-threatening agranulocytosis
MS
Acute: histologically, demyelination with relative preservation of axons, accumulation of lipid-laden macrophages, astrocytosis, infiltration by lymphocytes and mononuclear cells; chronic: loss of axons, neurons, and oligodendrocytes
Primary CNS lymphoma
Diffuse large B-cell lymphoma is m/c, cells positive for B-cell markers CD-20 and CD-79a; histo: dense, cellular aggregates of uniform, atypical lymphoid cells
Phenytoin moa
Inhibits neuronal high-frequency firing by reducing Na-channels ability to recover from inactivation
Cholernergic agonist effect
GI smooth muscle (N/V, ab cramps, diarrhea), cardiac (bradycardia, negative chronotropy, ionotropy, hypotension), periphery (vasodilation/hypotension, excess sweating/salivation, lacrimation), lungs (bronchoconstriction and increased bronchial secretion)
Bethanechol
Cholinergic agaonist to stimulate peristalsis in post-operative ileus and treat non-obstructive urinary retention 2/2 atonic bladder
Carbachol, pilocarpine
Lower IOP in glaucoma (2/2 cholinergic associated miosis moving iris further from cornea and increase anterior chamber angle)
Puffer fish poisoning moa
Tetrodotoxin binds to VG Na channels in nerve and cardiac tissue to prevent Na influx and depolarization; same MOA as saxitoxin produced by dinoflagelletes in red tide
Neuron injury: 12-48 hours
“Red neurons” with eosinophilic cytoplasm, pykonic nuclei, loss of Nissl substance
Neuron injury: 24-72 hours
Necrosis and PMN
3-5 days
MO infiltration and phagocytosis
1-2 weeks
Reactive gliosis and vascular proliferation (macroscopically, liquefactive necrosis with well-demarcated soft area, 1 week - 1 month)
> 2 weeks
Glial scare (macroscopically, cystic area surrounding by gliosis, >1 month)
Ventromedial
Stimulated by leptin, mediates satiety; destruction leads to hyperphagia
Lateral
Inhibited by leptin, mediates hunger; destruction leads to anorexia
Anterior
Mediates cooling/heat dissipation via P-ANS; destruction leads to hyperthermia
Posterior
Mediates heating/heat conservation via S-ANS; destruction leads to hypothermia
Arcuate
Secretion of DA, GnRH, gonadotropin
Paraventricular
ADH, CRH, oxytocin, TRH hormone
Supraoptic
ADH, oxytocin
Suprahiasmatic
Circadian rhythm regulation and pineal gland function
AMS
Mutation in copper-zinc superoxide dismutase (SOD-1); macro: thin anterior roots, mild atrophy of the precentral gyrus; micro: degeneration of lateral corticospinal tracts, loss of neurons in the anterior horn, loss of CN, denervation atrophy of muscles;
AChase inhibitors like organophosphate compounds
Prevent breakdown of ACh in NMJ, leads to muscarinic overstimulation; depolarizing blockade (muscle weakness, fasciculations, paralysis), miosis, bradycardia, increased lacrimation/salivation
Atropine/scopalamine
Competive antagonists of muscarinic ACh receptors, leads to ACh poisoning (cutaneous vasodilation, anhidrosis, hyperthermia, mydriasis, delirium)
Botulism
Nicotinic (descending paralysis, starting with diplopia, dysphagia, difficulty speaking) and muscarinic blockade (e.g. dry mouth); enters nerve through endocytosis and binds to ACh vesicles, preventing their release
Thiopental and cause of rapid plasma decay
Redistribution
Hypocretin-1 and hypocretin-2 function, deficiency results in?
Neuropeptides produced in lateral hypothalamus that promote wakefulness and inhibito REM sleep-related phenomena; deficiency results in nacrolepsy with cataplexy (CSF= undetectable levels of hypocretin-1)
Cataplexy
Conscious, brief episodes of b/l muscle tone loss precipitated by laughter/joking; or spontaneous, abnormal facial movements without emotional triggers
Drugs that increase levodopa in the CNS
DOPA decarboxylase inhibitor (L-Dopa), COMT inhibitors like entacapone (periphery)/tolcapone (periphery and central);
Stapedius muscle
Innervated by CN7; paralysis results in hyperacusis
Alzheimer MRI finding
Hippocampus atrophy, diffuse brain atrophy
Dividing point between anterior 2/3 and posterior 1/3 of tongue
Terminal sulcus and foramen cecum
Fragile X
X-linked, pw MR, dysmoprhic facial features (large jaw, protruding ears), macroorchidism
Klinefelter syndrome
47 XXY, pw tall stature, gynecomastia, small, firm testes, infertlity
Acute mania treatment
Mood stabilizer (lithium, valproate, carbamazepine) plus atypical AP (olanzapine)
Global cerebral ischemia
Watershed infarcts; present as bilateral wedge-shaped bands of necrosis over the cerebral convexity, just lateral to interhemispheric sphere; neurons lack glycogen and thus very susceptible to ischemia
DRESS
2-8 weeks after exposure to high-risk drug like anticonvulsant (phenytoin, carbamazepine, allopurinol, sulfonamides). Patients develop fever, generalized LN, facial edema, diffuse morbilliform skin rash, eosinophilila, and internal organ dysfunction
Severe vitamin E deficiency
Degeneration of spinocerebellar tracts, dorsal column of spinal cord, peripheral nerves; mimics symptoms of Friedreich ataxia (ataxia, dysarthria, dorsal column loss)
Mutations a.w. early-onset Alzheimer; mutations a.w. late-onset Alzheimer
Amyloid precursor protein (APP) on c21, presenilin 1 gene on c 14, presenilin 2 gene on c1; ApoE4
CN7 functon
Motor output to facial muscles, parasympathetic innervation to lacrimal, submandibular, sublingual salivary glands, taste fibers for anterior 2/3 of tongue, somatic affects from the pinna and external auditory cancal
Myotonic dystrophy
AD, increased trinucleotides on myotonia-protein kinase; sustained muscle contraction, weakness, muscle atrophy (Type 1 fibers), cataracts, frontal balding and gonadal atrophy
Phrenic nerve
Motor innervation to diaphragm, sensory innervation to thoracic viscera
Schizoaffective d/o
Psychosis must occur in the absence of major mood episodes, but mood symptoms have to be present for most of illness. In MDD or bipolar disorder with psychotic feature, pscychotic symptoms occur only in modd episodes
Neonatal intraventricular hemorrhage
Arises from fragile germinal matrix (highly cellular and vascluarized layer from which neurons and glial cells migrate out; the vessels lack glial fibers for support), increases in frequency with decreasing age and BW. Common complication of prematurity and can lead to neurodevelopmental impairment
Hydrocephalus vs hydrocephalus ex vacuo
Increase in CSF volume and pressure in forner; no increase in CSF pressure in the latter
SAH etiology, complications, related rx
saccular aneurysms, AV malformations; severe vasospasm 4-12 days after initial insult; Nimodipine
Temporal arteritis
Segmental, granulomatous infllamation of media of arteries; pw HA, jaw claudication, monocular blindness, polymyalgia rheumatica (neck, torso, shoulder, pelvic pain with stiffness with some systemic sx)
Transverse spinal cord section
More proximal levels have more white matter and more ovoid sections; lower cervical and lumbosacral regions have large ventral horns; thoracic and early lumbar sections ontain lateral horns (pre-symp ganglions)
First arch syndrome
Malformation of the mandible, maxilla, malleus, incus, palate, and temporal bone; associated with CN5
Schwannomas
histo: biphasic pattern of cellularity (antoni A, B areas) and S-100 positivity (NC origins); can arise from peripheral nerves, nerve roots, cranial nerves (except II)
Nasal hemianopia
Aneurysm or athersclerotic calcification of ICA can laterally impinge on optic chiasm and dmg uncrossed optic nerve fibers
Global cerebral ischemia
Most susceptible cells are pyramidal cells of the hippocampus and the neocortex and the purkinje cells of cerebellum. Hippocampus is the first area damaged during global cerebral ischemia.
HSV-1 encephalitis
Bilateral temporal lobes; pw aphasia, olfactory hallucinations (olfactory cortex), personality changes (amygdala)
Serotonin syndrome-inducing drugs when used with 5-HT drugs
Tramadol, ondansetron, and linezolid
MAO-I (phenelzine) SE
MAO is a mitochondrial enzyme, degrades excess neurotransmitter amines; MAO-I work by blocking degradation of amine NT (NE)to accumulate in pre-synaptic stores; food (wine, cheese, etc) containing tyramine (sympathomimetic) are typically metabolized in the GI tract, but MAO-I block this degradation and allow its release into circulation, HTN crisis
NT defects leaks what?
Alpha-fetoprotein and acetylcholinesterase
Atropine; undone by what?
reversible cholinergic antagonist; cholinesterase inhibitor (physostigmine)
Organophosphate poisoning moa, sx, and rx
Irreversible cholinesterase inhibition leads to cholinergic toxicity; pw excessive salivation, lacrimation, diaphoresis, urinary incontinence, diarrhea, emesis, miosis, bradycardia; rx with atropine (muscarinic antagonist) and pralidoxime (cholinesterase enzyme reactivator)
Akathisia
EPS SE of AP medication, pw inner restlessness and inability to sit/stand in one position. Misdiagnosed as agitation and AP dose incorrectly raised.
Pentazocine
Opioid narcotic designed to produce analgesia with reduced abuse potential; acts as a partial agaonist with weak antagonist acitivty at mu receptors; can come withdrawal symptoms in patients who are dependent/tolerent to opioids
Cystic tumor in the cerebellum of a child
pilocytic astrocytoma: well-differentiated neoplasm with spindle cells with hair-like glial processes, mixed with Rosenthal fibers and granular eosinophilic bodies
Cholinergic activity at blood vessels
Binds to muscarinic receptors on endothelial cells to promote NO/EDRF release; NO activiates guanylate cyclase, diminishes endothelium Ca concentration, which produces vasodilation
Cholinergic effect at GI
Cholinomimetics increase smooth muscle tone at visceral walls; increase motility and secretion in GI tract, leading to N/V, ab cramps, and diarrhea; contrarily, anti-Ch drugs relax GI wall and increase spinctor contraction, leading to constipation
Neuroblastoma
Increased number of N-myc genes, derived from neuroblasts in adrenal medulla, m/c extracranial childhood cancer; pw opsoclonus-myoclonus (non-rhythmic conjugate eye movement with myoclonus), HTN 2/2 increased catecholamines
Fragile X molecular mechanism
Fragile X mental retardation 1 (FMR-1) gene is on the X chromosome; increased CGG trinucleotide repeats leads to hypermethylation of cytosine and gene inactivation.
Schizophrenia
2/5 of following symptoms: delusions, hallucinations, disorganized speech, grossly symptoms, and negative symptoms (6 months)
NPH
Wet, wacky and wobbly; communicating hydrocephalus 2/2 diminshed reabsorptive capcacity of arachnoid villi; CT shows symmetrical dilatation
Marijuana immediate symptoms
Rapid heart rate and conjunctival injection
Mu receptor MOA
GPLR, increased K conductance and efflux, which leads to hyperpolarization of postsynaptic neurons to block pain transmission
Mid-pons infarct
CN 5, pw dysarthria, contra ataxic hemiparesis (contra because pontocerebellar fibers enter through contralateral cerebellar peduncle)
Three types of signal pathways in ANS
cAMP: Beta 1, 2, M2; IP3: alpha 1, M1, M3 ; ion channel: nicotinic receptors (ligand-gated ion channels that open after binding with ACh and results in immediate influx of Na, Ca and outflow of K)
Central SE of dopamine that are worsened with the addition of carbidopa
Anxiety and agitation
CN3 pathway, components, and pathology
Exits midbrain and courses between the PCA and superior cerebellar arteries (susceptible to related aneurysms); parasym fibers (responsible for pupillary light and near-reflex pathways) susceptible to compression (aneurysm/tumor); somatic fibers (oculomotor muscles) susceptible to injury from ischemia (DM)
Examples of malformation (primary abnormality in development), disruption (secondary destruction of previously well-formed tissue or organ), deformation (secondary to extrinsic problem), sequence (single primary defect leads to multiple manifestations)
Holoprosencephaly (failure of forebrain cleavage into cerebral hemisphere); amniotic band syndrome (rupture of amnion leads to band formation that can compress limbs); congeintal hip displication/clubbed feet/flat facies 2/2 oligohydramnios; Potter syndrome
Trazadone moa, main SE
Highly sedating anti-depressant for insomnia, adjunct to SSRI in treating depression-related insomnia; priapism
Liquefactive necrosis
Complete digestion and removal of necrotic tissue: first, ischemic neurons release lysosomal enzymes to degrade the tissue, then phagocytes migrant and remove necrotic tissue before astrocytes proliferate and form scar (gliosis)
Drug-induced parkinsonism
Blockage of D2 receptors lead to rigidity, bradykinesia, tremor, masked facies; rx by decreasing drugs or giving benztropine or amantadine; levodopa or other DA agonists (e.g. bromocriptine) are contraindicated as they may precipitate psychosis
Vita E deficiency MOA
Protects FA from oxidation; thus, cell membranes with high FA content (neurons/RBC) prone to damange in deficiency; pw neuromuscular disease (spinocerebellar ataxia, dorsal column sensory loss) and hemolytic anemia
Acute neuronal injury
Shrinkage of cell body, shrunken/basophilic nucleus, loss of Nissl substance, eosinophilic cytoplasm
Axonal reaction 2/2 loss of axon
Enlargement of cell body, eccentric nucleus, enlargement of the nucleolus, dispersion of Nissl substance
Neuronal atrophy 2/2 progressive degenerative dz
Loss of neurons, reactive gliosis
“On-off” phenomena in advanced PD
Unpredictable, dose-independent loss of L-dopa effects ; but do not increase dose, which will not improve motor symptoms and carry higher risk of dyskinesia
Buspirone MOA
Selective agonist of 5-HT1a receptor, safe and effective for GAD. No hypnotic, sedative, or euphoric effects. Not effective for panic d/o, phobias. No dependence over time. Clinical response delayed up to 2 weeks.
Hydrocephalus in infant pw, long-term complications?
irrability, poor feeding, increased head circumference, enlarged ventricles; LE spasticity 2/2 stretching of periventricular pyramidal tracts, visual disturbances, learning disabilities
Which anti-depressants induce mania?
All can, but venlafaxine and TCA are most likely
Penicillin and cephalosporins moa
Bind to penicillin-binding proteins like transpeptidase (NOT cell wall glycoproteins)
PD treatment
Selegiline (MAO-I that prevents MPTP induced dmg of DA neurons), amantadine (DA agonist with anti-ACh activity) , ACh
Astrocytes
Neuroectoderm origin, contain glial fibrillary acidic protein (GFAP), functions are to repair, structural support, maintain BBB, metabolic
Oligodendrocytes
Neuroectoderm, small round dark nuclei surrounded by pale halo, production of myelin
Microglia
BM-originated MO, small, elongated nuclei, phagocytosis
Direct Xa inhibitors
Increase PT, aPTT
Unfractionated heparin and direct thrombin inhibitors
Increase thrombin time
Motion sickness stimulated by what receptors, medications?
M1 muscarinic and H1 histaminic receptor; meclizine (anti-histaminic with anti-muscarinic properties) or scopalamine (anti-muscarinic properties only)
Valproate acid teratogenic effect
NT defect
Blotchy red muscle fibers on gomori trichome stain is evidence of what? What is an example?
Mitochondrial myopathy; myoclonic epilepsy with ragged red fibers
MS plaques
Loss of myelin sheathes and depletion of oligodendrocytes; oligocloncal bands of IgG on CSF analysis
Progressive multifocal leukoencephalopathy
Oligodendrocyte depletion
Scotoma
Visual field defect that involves retina or optic nerve that results in a discrete area of altered vision surrounded by zones of normal vision (2/2 MS, diabetic retinopathy, macular degeneration); lesions of the macula cause central scomatas
In the US, majority of OD deaths related to
Opioid analgesics
Treatment for GAD, panic disorder
SSRI with short-term BZD (4 weeks)
BZD best for treating insomnia in patients employed in critical positions
Trazolam
CN9 lesions
Loss of gag reflex (2/2 afferent limb loss), loss of sensation in upper pharynx, posterior tongue, tonsils, middle ear cavity and loss of taste sensation in posterior 1/3 of tongue
Neuroleptic malignant syndrome
Haloperidol; pw hyperthermia, extreme rigidity, ANS instability, AMS; different from serotinin syndrome in the presence of rigidity and absence of myoclonus; rx with DA agonists like bromocriptine and/or muscle relaxants like dantrolene
ETOH withdrawal
tremulousness (first), anxiety, angitation, ANS disturbance, GI distress; DT can occur between 2-3 days of last drink
Conus medullaris syndrome
Flaccid paralysis of bladder/rectum, impotence, saddle anesthesia
Cauda equina
Low back pain radiating downwards, saddle anesthesia, loss of “anal wink,” bowel/bladder dysfunction (S3-S5), and loss of ankle-jerk reflex
Light reflex pathway
CN2, pretectal nucleus (near superior colliculus), ipsi/contra edinger-westphal (decussating via posterior commissure), motor neuron preganglionic neurons in edinger-westphal nucleus, CN3, ciliary ganglion, post-ganglionic neurons, iris spincter
NF2
NF2 tumor suppressor gene that codes for merlin on c22; pw b/l acoustic neuromas
NF1
NF1 -1 gene mutation on c17, AD
Lamotrigene SE
Refractory partial seizures; SE that is life-threatening in children
Micturition reflex
- Sacral micturition center: located in S2-S4 and responsible for bladder contraction. Parasympathetic fibers travel down and stimulate cholinergic receptors on bladder wall. 2. Cerebral cortex: inhibits sacral micturition center. 3. Pontine micturition center: located in the pontine reticular formation, and coordination relaxation of external urethral spincter with bladder contraction during voiding.
Lacunar stroke to subthalamic nucleus
Contra hemiballism
Lacunar infarcts
<15 mm in diameter in BG, pons, internal capsule, deep white matter; most often occur with hypertensive arteriosclerosis of small, penetrating arteries
Lacunar infarts: location and effect? pure motor hemiparesis, pure sensory, ataxia-hemiplegia syndrome, dysarthria-clumsy hand syndrome
Posterior limb of internal capsule, VPL/VPM thalamus, base of pons, base of pons/genu of internal capsule
Diseases with anticipation
Huntington, Fragile X, mytonic dystrophy, Friedreich ataxia
Primidone metabolites
Phenobarbitol and phenylethylmalonamide (all three compounds are active anticonvulsants)
First generation anti-histaminics (diphenhydramine, chlorpheniramine) MOA and SE
Decrease the activity of H1 histamine receptor by increasing the proportion of inactive H1 receptors (reverse blockade); antimuscarinic (pupillary dilation, dry mouth, urinary retention, and constipation), anti-adrenergic (hypotension, postural dizziness), and anti-seroternergic (appetite stimulation and weight gain)
Phenytoin SE
Gingival hyperplasia (2/2 increased PDGF, stimulation of gingival macrophages, stimulation proliferation of gingival cells and alvelar bone), ataxia/nystagmus (cerebellum and vesticular system); megaloblastic anemia 2/2 interference with FA metabolism, P450 cytochrome inducer; teratogen (fetal hydantoin syndrome)
Lithium toxicity
Neuromuscular excitability (course tremors, fascicular twitching, agitation, ataxia), nephrogenic DI, hypothyroidism, cardiac conduction defects
Alpha 1: receptor locations and agonists
Peripheral vasculature (increase SBP); bladder (contraction of internal urethral spincter; eye (contraction of pupillary dilator muscle); epi, NE, phenyleprhine
Beta 1: receptor location and agaonists
Heart (chronotropy, ionotropy); epi, dopamine, dobutamin, isoproterenol
Beta 2
Peripheral vasculature in SK muscle (vasodilation, decreased DBP), bronchi (bronchodilation), uterus (relaxation/tocolysis); isoproterenol, terbutaline
BZD choice in ETOH withdrawal
Long-acting (diazepam, chlordiazepoxide); short-acting (lorazepam, oxazepam) for liver failure patients
Atropine SE on eyes
Myadrisis, preciptating closed-angle glaucoma, pw unilateral severe eye pain and visual disturbances
Syringomyelia
Fixed segmental loss of UE P/T, UE LMN signs, LE UMN in setting of scoliosis
Rx for bipolar disease and seizure prophylaxis, and related SE
Valproate (hepatotoxicity, NT defect); Carbamazapine (agranulocytosis, hyponatremia, NT defect, CYP450 inducer); Lamotrigine (SJS in children)
Cocaine MoA
indirect sympathomimetic by inhibiting the presynaptic reuptake of NE, DA, 5-HT; also causes vasoconstriction of heart and atrophy of nasal mucosa/septum
Naloxone MoA
Pure opioid receptor antagonist, used in OD, with greatest affinity for mu receptors, given parenterally
Polyhydramnios moa, etiologies
Decreased fetal swallowing (2/2 duodenal, esophogeal, intestinal atreia or anencephaly) or increased urination (high cardiac output 2/2 anemia or TTFS)
Lithium SE
hypothyroidism, nephrogenic diabetes inspidus, accumulation in patients with renal insufficiency
Alzheimer disesae MOA
Diminished activity of choline acetyltransferase in the nucleus basalis of Maynert and hippocampus
SSRI SE
sexual dysfunction
TCA SE
Urinary retention, cardiac arrhythmias (QT prolongation), seizures, orthostatic hypotension
Sciatica: compression of S1
Pain in posterior thigh and leg, diminution of the ankle jerk reflex
Sciatica: compression of L5
Posterior and lateral thigh and leg pain shooting to the inner foot
Determinants of inhaled anesthetic onset of action
Tension in inhaled air, pulmonary ventilation rate, solubility in blood, solubility in peripheral tissue
Friederich ataxia
AR, trinucleotide repeat in frataxin gene, pw cerebellar ataxia, loss of position and vibration sensation, kypohscoliosis, hypertrophic cardiomyopathy. Foot abnormalities and DM also common.
Buproprion indications, SE, contraindications
Major depression, tobacco dependence, hypoactive sexual disorder; seizures; patient with seizure disorder or bulimia/anorexia diagnosis
Medications with seizure as a SE
buproprion, clozapine, isoniazid, ciprofloxacin, imipenim
ADPKD patient presents with HA
Intracranial berry aneurysm presents with SAH
Atropine MOA, limitation as rx for organophosphate poisoning, and supplemental rx
Competitively binds muscarinic ACh receptors; pt still at risk for muscle paralysis (2/2 nicotinic receptors); rx with pralidoxime (“restores” AChase from its bonds to the organophosphate)
Meniere dz MOA, pw
defective resorption of endolymph leads to increased volume of endolymph; pw tinnitus, vertigo, and sensorineural hearing loss
Macular sparing in PCA stroke 2/2
Collateral blood from MCA to the occipital pole
OHS moa, pw
Obesity impedes expansion of chest and abdominal wall, creating increased respiratory work and decreased respiratory drive; pw hypercapnia, hypoxia
Cimetidine moa, se
H2-receptor blocker; gynecomastia, inhibit P450 (increasing warfarin, phenytoin, propanolol, metoprolol, quinidine, theophyline)
What vitamin increases peripharal metabolism of levodopa?
B6
Phrenic nerve irritation pw
Hiccups, diphragmatic paralysis with dyspnea
Paraneoplastic cerebellar degeneration
Small cell lung cancer, breast/ovarian/uterine cancer; worsening dizziness, limb/truncal ataxia, dysarthria, visual disturbance (diplopia); immune response against tumor cells that cross-reacts with Purkinje neuron antigens; anti-yo, anti-P/Q, anti-hu
Huntington mutation
Gain of function mutation that leads to increased histone deacetylation and transcriptional silencing of genes needed for neuronal survival;
Atypical depression pw, rx
Mood reactivity (positive response to positive events), leaden fatigue, rejection sensitivity, and increased sleep/appetite; MAO-I like phenelzine is particularly helpful
TCA SE
Inhibition of muscarinic receptors (tachycardia, delirium, dilated pupils, flushing, decreased diaphoresis, hyperthermia, intestinal ileus, urinary retention); peripheral alpha-1 adrenergic (peripheral vasodilation and orthostatic hypotension); cardiac fast Na channels (arrhythmias), presynaptic NT reuptake (seizures, tremors), H1 receptors (sedation)
Narcolepsy treatment
Scheduled daytime naps and modafinil (non-amphetamine) stimulant
Migraine moa, rx
Activation of trigeminal afferents that innervate meninges, which release vasoactive neuropeptides (substance P and calcitonin gene-related peptide); sumatripan (5-HT1b/5-HT1D) agonists directly counter the pathophysiologic mechanism by inhibiting the release of vasoactive peptides and promoting vasoconstriction.
Carpel tunnel etiologies
Hypothyroidism, diabetes mellitus, RA, dialysis-related amyloidosis
MG: myasthenic and cholinergic chrisis
Myasthenic crisis: not enough neostigmine, not enough ACh; cholinergic crisis: too much neostigmine, too much ACh; Clinical improvement after edrophonium administration means myasthenic crisis
Patient feints after inserting a speculum into the posterior wall of the external auditory meatus
Vagus nerve provides some cutaneous sensation to the posterior external auditory cancel by small auricular branch
P450 Inducer
Rifampin, carbamazepine, phenobarbital, chronic ETOH consumption, griseofulvin
P450 inhibitor
Isoniazid, cimetidine, macrolides, azole antifungals, and grapefruit juice
BZD
Increase the frequency of opening of CNS GABAa receptor chloride channels and have anxiolytic, anticonvulsant, muscle relaxant, sedative-hypnotive effects
Barbituates
increase the duration of opening of the GABAa receptor-chloride in CHS neurons
TCA-related cardiac abnormalities: treat with?
sodium bicarbonate
Minimal alveolar concentration
Concentration of anesthetic in alveoli needed to render 50% of patients unresponsive to painful stimuli; measures potency of inhaled anesthetic
Physostigmine vs neostigmine/edrophonium
Former penetrates CNS/periphery; latter cannot cross BBB
MELAS
Mitochondrial encephalopathy with Lactic Acidosis and Stroke like episodes
2nd generation anti-histamine
Fexofenadine, with minimal sedative and antimuscarinic effects
Deep branch of the radial nerve
Arises from the lateral epicondyle of the humerus; radial head subluxation can dmg this nerve and cause weakness of the forearm/hand extensors but no sensory deficits
Wilson’s disease causes cystic degeneration in what structure?
putamen
Methadone special characteristic
Long half-life allows for prolonged ability to suppress withdrawal symptoms
Korsakoff syndrome
Permanent memory loss and confabulation
Charcot-Bouchard pseudoaneurysms
A.w. HTN-induced hyaline arteriosclerosis in BG and internal capsule; <1 mm; intracerebral hemorrhage; sudden onset of focal deficits
Subacute sclerosing panencephalitis (SSPE)
Complication of measles; virus with absent matrix protein proliferate intracellularly and accumulate viral nucleocapsids within neurons, intranuclear inclusions eventually lead to inflammation, demyelination, gliosis; present with high titers of measles antibodies in serum and csf
Friedreich ataxia
AR, mutation on c9 has increased trinucleotide repeats; a.w. hypertrophic cardiomyopathy, DM, kyphoscoliosis, foot deformities
