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Flashcards in Principles in Neurology_3 Deck (317):
1

clinical features of CJD?

rapidly progressive dementia with myoclonus

2

what are the histologic/gross findings in CJD?

spongiform cortex • prions (PrPc→PrPsc sheet [β-pleated sheet resistant to proteases])

3

what is MS?

autoimmune inflammation and demyelination of CNS

4

Patients with MS can present how?

optic neuritis • MLF syndrome • hemiparesis • hemisensory symptoms • bladder/bowel incontinence

5

what is the course in MS?

relapsing and remitting

6

MS most often affects who?

women in their 20's and 30's; more common in whites

7

what is Charcot's classic triad of MS?

a SIN: • Scanning speech • Intention tremor/Incontinence/INO • Nystagmus

8

what are the findings in MS?

↑ protein (IgG) in CSF • Oligoclonal bands are diagnostic • MRI is gold standard • Periventricular plaques with destruction of axons

9

what is the treatment for MS?

β-interferon, immunosuppression, natalizumab • symptomatic tx for neurogenic bladder, spasticity, and pain

10

what is the most common variant of Guillain-Barre syndrome?

Acute Inflammatory demyelinating polyradiculopathy

11

what is acute inflammatory demyelinating polyradiculopathy?

autoimmune condition that destroys Schwann cells → inflammation and demyelination of peripheral nerves and motor fibers

12

acute inflammatory demyelinating poly radiculopathy results in what?

symmetric ascending muscle weakness/paralysis beginning in lower extremities • facial paralysis in 50% of cases • autonomic dysfunction

13

prognosis of acute inflammatory demyelinating polyradiculopathy?

almost all patients survive; majority recover completely after weeks to months

14

what are the findings in acute inflammatory demyelinating polyradiculopathy?

↑CSF protein with normal cell count (albuminocytologic dissociation). • ↑protein →papilledema

15

acute inflammatory demyelinating polyradiculopathy is associated with which infections?

Campylobacter jejuni and CMV

16

how does infection cause acute inflammatory demyelinating polyradiculopathy?

autoimmune attack of peripheral myelin due to molecular mimicry, inoculations, and stress, but no definitive link to pathogens

17

Tx for acute inflammatory demyelinating polyradiculopathy?

respiratory support is critical until recovery. • additional: plasmapharesis, IV immune globulins

18

what is progressive multifocal leukoencephalopathy?

demyelination of CNS due to destruction of oligodendrocytes

19

PML is associated with what?

JC virus

20

PML is seen in which patients?

2-4% of AIDS patients

21

prognosis of PML?

rapidly progressive, usually fatal

22

what is acute disseminated (postinfectious) encaphalomyelitis?

multifocal perivenular inflammation and demyelination after infection (measles or VZV) or vaccination (rabies, small pox)

23

what is metachromatic leukodystrophy?

autosomal recessive lysosomal storage disease, most commonly due to aryl sulfatase A deficiency.

24

what causes demyelination in metachromatic leukodystrophy?

build up of sulfatides leads to impaired production of myelin sheath

25

Charcot-Marie-Tooth disease is AKA what?

hereditary motor and sensory neuropathy

26

what is HMSN?

group of progressive heeditary nerve disorders related to the defective production of proteins involved in the structure and function of peripheral nerves or the myelin sheath

27

What is Krabbe's disease?

AR lysosomal storage disease due to deficiency of galactocerebrosidase

28

how does Krabbe's disease cause demyelination?

build up of galactocerebroside destroys myelin sheath

29

seizures are characterized by what?

synchronized high frequency neuronal firing

30

partial seizures affect what?

1 area of the brain

31

partial seizures most commonly originate where?

medial temporal lobe

32

partial seizure is often preceded by what?

seizure aura

33

secondary consequence of some partial seizures?

can secondarily generalize

34

what are the types of partial seizure?

simple partial • complex partial

35

what is a simple partial seizure?

consciousness intact: • motor, sensory, autonomic, psychic

36

what is a complex partial seizure?

partial seizure with impaired consciousness

37

what is epilepsy?

a disorder of recurrent seizures- excluding febrile seizures

38

what is status epilepticus?

continuous seizure for >30 min or recurrent seizures without regaining consciousness between seizures for >30min

39

what are the causes of seizures in children?

genetic • infection (febrile) • trauma • congenital • metabolic

40

what are the causes of seizures in adults?

tumors • trauma • stroke • infection

41

what are the causes of seizures in the elderly?

stroke • tumor • trauma • metabolic • infection

42

what are the types of generalized seizures?

Absence (petit mal) • myoclonic • tonic-clonic (grand mal) • tonic • atonic

43

features of absence seizure?

3Hz • no postictal confusion • blank stare

44

features of myoclonic seizure?

quick repetitive jerks

45

features of tonic-clonic seizure?

alternating stiffening and movement

46

features of tonic seizure?

stiffening

47

features of atonic seizure?

drop' • commonly mistaken for fainting

48

head aches are all characterized by what?

pain due to structures such as the dura, cranial nerves, or extracranial structures

49

localization of cluster HA?

unilateral

50

duration of cluster HA?

15min-3hr; repetitive

51

clinical presentation of cluster HA?

repetitive brief HA. excruciating periorbital pain with lacrimation and rhinorrhea

52

cluster HA may induce what?

Horner syndrome

53

cluster HA is more common in whom?

males

54

what is the treatment for cluster HA?

inhaled O2 • sumatriptan

55

localization of tension headache?

bilateral

56

duration of tension HA?

>30 min (~4-6hr); constant

57

clinical presentation of tension HA?

steady pain. no photophobia or phonophobia. no aura

58

localization of migraine HA?

unilateral

59

duration of migraine HA?

4-72hr

60

clinical features of migraine?

pulsating pain with nausea, photophobia, phonophobia, aura

61

what causes migraine?

irritation of CN V, meninges, or blood vessels (release of substance P, GCRP, vasoactive peptides)

62

what are the abortive therapies for migraine?

triptans

63

what are the prophylactic therapies for migraine?

propanolol • topiramate

64

what is vertigo?

sensation of spinning while stationary

65

what is the more common type of vertigo?

peripheral vertigo

66

what causes peripheral vertigo?

inner ear etiology: • semicircular canal debris • vestibular nerve infection • Menieres disease

67

what is the finding of positional testing in peripheral vertigo?

delayed horizontal nystagmus

68

what causes central vertigo?

brainstem or cerebellar lesion: • stroke affecting vestibular nuclei • posterior fossa tumor

69

what are the findings in central vertigo?

directional change of nystagmus • skew deviation • diplopia • dysmetria

70

results of positional testing in central vertigo?

immediate nystagmus in any direction; may change directions

71

what are the neurocutaneous disorders?

1. Sturge-Weber syndrome • 2. Tuberous sclerosis • 3. NF1 • 4. Von Hippel-Lindau disease

72

what is Sturge-Weber syndrome?

congenital disorder with port-wine stains (nevus flammeus) typically in V1 ophthalmic distribution

73

what tumors are seen with Sturge-Weber syndrome?

leptomeningeal angiomas • pheochromocytomas

74

Sturge Weber syndrome can cause what?

glaucoma • seizures • hemiparesis • MR

75

inheritance of Sturge-Weber syndrome?

occurs sporadically

76

clinical features of Tuberous Sclerosis?

HAMARTOMAS: • Hamartomas in CNS and skin • Adenoma sebaceum (cutaneous angiofibroma) • Mitral regurgitation • Ash-leaf spots • cardiac Rhabdomyoma • Tuberous sclerosis • autosomal dOminant • Mental retardation • Angiomyolipoma • Seizures

77

what are the clinical features of NF1?

Cafe-au-lait spots • Lisch nodules • neurofibromas in skin • optic gliomas • pheochromocytomas

78

genetic features of NF1?

AD • 100% penetration • variable expressivity • mutated NF1 gene on chromosome 17

79

what are the clinical features of VonHippel-Lindau disease?

Cavernous hemangiomas in skin, mucose, organs; • bilateral RCC • hemangioblastoma in retina, brainstem, cerebellum; • pheochromocytomas

80

genetic features of VonHippel-Lindau disease?

AD • mutated tumor suppressor VHL gene on chromosome 3

81

what is the most common 1° brain tumor in adults?

GBM/ Grade IV astrocytoma

82

prognosis for GBM?

malignant with <1yr life expectancy

83

where is GBM found?

cerebral hemispheres • can cross corpus callosum (butterfly glioma)

84

how do you stain GBM?

stain astrocytes for GFAP

85

histologic findings in GBM?

pseudopalisading pleomorphic tumor cells- border central areas of necrosis and hemorrhage

86

what is the 2nd most common 1° brain tumor in adults?

meningioma

87

meningioma most commonly occurs where?

in convexities of hemispheres (near surfaces of brain) and parasagital region

88

morphologic features of meningiomas?

1. arise from arachnoid cells • 2. are extra-axial (external to brain parenchyma) • 3. may have a dural attachment (tail)

89

prognosis of meningioma?

typically benign and resectable

90

clinical presentation of meningioma?

often asymptomatic; may present with seizures or focal signs

91

what is the 3rd most common 1° brain tumor in adults?

Schwannoma

92

morphologic features of Schwannoma?

Schwann cell origin; often localized to CNIII →acoustic neuroma

93

treatment for Schwannoma?

resectable or treated with stereotactic radiosurgery

94

Schwannoma is usually found where?

cerebellopontine angle

95

how does a Schwannoma stain?

S-100 positive

96

bilateral acoustic neuromas found in what?

NF2

97

frequency of oligodendroglioma?

relatively rare, slow growing

98

oligodendroglioma is most often located where?

frontal lobes

99

morphologic features of oligodendroglioma?

chicken wire capillary pattern • oligodendrocytes= fried egg cells- round nuclei with clear cytoplasm • often calcified in oligodendroglioma

100

pituitary adenoma is most commonly what?

prolactinoma

101

symptoms of prolactinoma?

bitemporal hemianopia and hypo/hyperpituitarism

102

what are the childhood primary brain tumors?

1. pilocytic (low-grade) astrocytoma • 2. medulloblastoma • 3. ependymoma • 4. hemangioblastoma • 5. craniopharyngioma

103

morphologic features of pilocytic astrocytoma?

well circumscribed • cystic and solid

104

where is pilocytic astrocytoma most often found in children?

posterior fossa/cerebellum • may be supratentorial

105

how does pilocytic astrocytoma stain?

GFAP positive

106

prognosis of pilocytic astrocytoma?

benign • good prognosis

107

histologic findings in pilocytic astrocytoma?

Rosenthal fibers- eosinophilic corkscrew fibers

108

what is a medulloblastoma?

highly malignant cerebellar tumor • form of primitive neuroectodermal tumor

109

medulloblastoma can compress what?

4th ventricle → hydrocephalus

110

how does medulloblastoma metastasize?

can send drop mets to spinal cord

111

morphologic findings in medulloblastoma?

Horner-Wright rosettes • Solid • small blue cels

112

treatment of medulloblastoma?

radiosensitive

113

ependymal cell tumors are most commonly found where?

in 4th ventricle

114

ependymal cell tumors can cause what?

hydrocephalus

115

prognosis of ependymal tumors?

poor

116

morphologic findings in ependymoma?

characteristic perivascular pseudorosettes. rod-shaped blepharoplasts (basal ciliary bodies) found near nucleus

117

hemangioblastomas in the brain are most often where?

cerebellum

118

hemangioblastomas are associated with what condition when seen with retinal angiomas?

VonHippel Lindau disease

119

hemangioblastomas can produce what?

erythropoietin→2° polycythemia

120

what findings are characteristic of hemangioblastoma?

foamy cells and high vascularity

121

what is a craniopharyngioma?

benign childhood tumor, confused with pituitary adenoma (can also cause bitemporal hemianopia)

122

what is the most common childhood supratentorial tumor?

craniopharyngioma

123

craniopharyngioma is derived from what?

Rathke's pouch

124

morphological features of craniopharyngioma?

calcification is common (tooth enamel like)

125

what are the herniation syndromes?

1. cingulate (subfalcine) herniation under falx • 2. downward transtentorial (central) herniation • 3. uncal herniation • 4. cerebellar tonsillar herniation into the foramen magnum

126

cingulate herniation under falx can do what?

compress ACA

127

where is the uncus?

medial temporal lobe

128

complications of cerebellar tonsilar herniation into the foramen magnum?

coma and death result when these herniations compress the brain stem

129

what do glaucoma drugs do?

↓ IOP via ↓ amount of aqueous humor (inhibit synthesis/secretion or increase drainage)

130

what are the classes of glaucoma drugs?

α1-agonists • β-blockers • diuretics • cholinomimetics • prostaglandin

131

what are the α agonists used to treat glaucoma?

Epinephrine • Brimonidine (α2)

132

what is the MOA of epinephrine for glaucoma?

↓ aqueous humor via vasoconstriction

133

what is the MOA of brimonidine for glaucoma?

↓ aqueous humor synthesis

134

what are the side-effects of epinephrine for glaucoma?

mydriasis; do not use in closed angle glaucoma

135

what are the side effects of brimonidine for glaucoma?

Blurry vision, ocular hyperemia, foreign body sensation, ocular allergic reactions, ocular pruritus

136

what are the β-blockers used for glaucoma?

timolol • betaxolol • carteolol

137

what is the MOA of timolol, betaxolol, and carteolol for glaucoma?

↓ aqueous humor synthesis

138

what are the side effects of timolol, betaxolol, and carteolol for glaucoma?

no pupillary or vision changes

139

what are the diuretics used for glaucoma?

acetazolamide

140

what is the MOA of acetazolamide for glaucoma?

↓aqueous humor synthesis via inhibition of carbonic anhydrase

141

what are the side effects of acetazolamide for glaucoma?

no pupillary or vision changes

142

what are the direct cholinomimetics used for glaucoma?

pilocarpine, carbachol

143

what are the indirect cholinomimetics used for glaucoma?

physostigmine • echothiophate

144

what is the mechanism of action of cholinomimetics for glaucoma?

↑ outflow of aqueous humor via contraction of ciliary muscle and opening of trabecular meshwork

145

what are the side effects of cholinomimetics for glaucoma?

miosis and cyclospasm

146

which drug should be used for glaucoma emergency?

pilocarpine- very effective at opening meshwork into canal of Schlemm

147

what is the prostaglandin used for glaucoma?

Latanoprost (PGF2α)

148

what is the MOA of latanoprost?

↑ outflow of aqueous humor

149

what are the side effects of latanoprost for glaucoma?

darkens color of iris

150

which drugs are opioid analgesics?

1. morphine • 2. fentanyl • 3. codeine • 4. heroin • 5. methadone • 6. meperidine • 7. dextromethorphan • 8. diphenoxylate

151

what is the MOA of opioid analgesics?

agonists at opioid receptors to modulate synaptic transmission- open K+ channels, close Ca2+ channels→ ↓ synaptic transmission • - inhibit release of ACh, NE, 5-HT, glutamate, substance P

152

what is the clinical use of opioid analgesics?

pain, cough suppression (dextromethorphan), diarrhea (loperamide and diphenoxylate), acute pulmonary edema, maintenance programs for addicts (methadone)

153

what happens in opioid analgesic toxicity?

addiction • respiratory depression • constipation • miosis (pinpoint pupils) • additive CNS depression with other drugs

154

there is no tolerance to which side effects of opioids?

miosis • constipation

155

opioid toxicity is treated with what?

naloxone or naltrexone (opioid receptor antagonist)

156

what stimulates opioid mu receptor?

morphine

157

what stimulates opioid delta receptor?

enkephalin

158

what stimulate opioid kappa receptor?

dynorphin

159

what is the MOA of Butorphanol?

mu-opioid receptor partial agonist and kappa-opioid receptor agonist; produces analgesia

160

what is the clinical use of Butorphanol?

severe pain (migraine, labor, etc.) causes less respiratory depression than full opioid agonists

161

what happens in butorphanol toxicity?

can cause opioid withdrawal symptoms if patient is also taking full opioid agonist (competition for opioid receptors). overdose not easily reversed with naloxone

162

what is the MOA of tramadol?

very weak opioid agonist; also inhibits 5HT and NE reuptake (works on multiple neurotransmitters)

163

what is the clinical use of tramadol?

chronic pain

164

what happens in tramadol toxicity?

similar to opioids. decreases seizure threshold

165

What kind of seizures do you treat with phenytoin?

- 1st LINE: Tonic-Clonic + Prophylaxis of status epilepticus • - Simple and complex partial

166

what type of seizures do you treat with carbamazepine?

1st LINE: Simple and complex partial + Tonic-Clonic

167

which types of seizures do you treat with lamotrigine?

- Simple and complex partial • - Generalized tonic-clonic

168

which types of seizures do you treat with gabapentin?

- Simple and complex partial • - generalized tonic-clonic

169

which types of seizures do you treat with topiramate?

- Simple and Complex Partial • - Generalized Tonic-clonic

170

which types of seizures do you treat with phenobarbital?

- Simple and complex partial • - generalized tonic-clonic

171

which types of seizures do you treat with Valproate?

1st LINE: Tonic-Clonic • - Simple and Complex partial • - absence

172

which types of seizures do you treat with ethosuxamide?

1st LINE: absence

173

which types of seizures do you treat with Benzodiazepines?

1st LINE: acute status epilepticus

174

which types of seizures do you treat with tiagabine?

simple and complex partial seizures

175

which types of seizures do you treat with vigabatrin?

simple and complex partial

176

which types of seizures do you treat with levetiracetam?

- simple and complex partial • - generalized tonic clonic

177

what is the first line treatment for prohpylaxis of Status epilepticus?

phenytoin

178

what is the 1st line treatment for acute status epilepticus?

benzodiazepines

179

what is the first line treatment for absence seizures?

ethosuxamide

180

what are the first line treatments for tonic-clonic seizures?

phenytoin • carbamazepine • valproic acid

181

what are the first line treatments for simple and complex partial seizures?

carbamazepine

182

MOA of phenytoin?

use dependent blockade of Na channels; inhibition of glutamate release from excitatory presynaptic neuron

183

how do you give parenteral phenytoin?

Fosphenytoin

184

MOA of carbamazepine?

↑ Na+ channel inactivation

185

which drug is the 1st line treatment for trigeminal neuralgia?

carbamazepine

186

MOA of lamotrigine?

blocks voltage gated Na+ channels

187

what is the MOA of gabapentin?

designed as GABA analog, but primarily inhibits high-voltage-activated Ca++ channels

188

gabapentin is used for what other than seizures?

peripheral neuropathy • postherpetic neuralgia • migraine prophylaxis • bipolar disorder

189

MOA of topiramate?

blocks Na+ channels • ↑GABA action

190

topiramate is used for what other than seizures?

migraine prevention

191

MOA of phenobarbital?

↑GABAa action

192

when is phenobarbital 1st line?

in children

193

MOA of valproic acid?

↑Na+ channel inactivation, • ↑ GABA concentration

194

valproic acid can be used for which unusual type of seizure?

myoclonic seizure

195

MOA of ethosuxamide?

blocks thalamic T-type Ca++ channels

196

MOA of diazepam/lorazepam?

↑GABAa action

197

benzodiazepines are used for what in pregnancy?

seizures in eclampsia, but 1st line is MgSO4

198

MOA of tiagabine?

inhibits GABA reuptake

199

MOA of vigabatrin?

irreversibly inhibits GABA transaminase →↑GABA

200

MOA of levetiracetam?

may modulate GABA and glutamate release

201

Benzodiazepine toxicity?

Sedation • Tolerance • Dependence

202

Carbamazepine toxicity?

Diplopia • ataxia • blood dyskrasias (agranulocytosis, aplastic anemia) • liver toxicity • teratogenesis • P450 induction • SIADH • SJS

203

ethosuxamide toxicity?

GI distress • fatigue • headache • urticaria • SJS

204

phenobarbital toxicity?

Sedation • tolerance • dependence • induction of P450

205

Phenytoin toxicity?

nystagmus • diplopia • ataxia • sedation • gingival hyperplasia • hirsutism • megaloblastic anemia (↓folate absorption) • teratogenesis (fetal hydantoin syndrome) • SLE like syndrome • induction of P450 • lymphadenopathy • SJS • osteopenia

206

Valproic acid toxicity?

GI distress • rare but fatal hepatotoxicity • NTD • tremor • weight gain • CI in pregnancy

207

toxicity of lamotrigine?

SJS

208

gabapentin toxicity?

sedation • ataxia

209

topiramate toxicity?

sedation • mental dulling • kidney stones • weight loss

210

clinical presentation of SJS?

prodrome of malaise and fever followed by rapid onset of erythematous/purpuric macules • skin lesions progress to epidermal necrosis and sloughing

211

Clinical use of phenytoin?

tonic-clonic seizures • class 1B antiarrhythmic

212

which drugs are the barbiturates?

phenobarbital • pentobarbital • thiopental • secobarbital

213

mechanism of action of Barbiturates?

facilitate GABAa action by *↑ duration* of Cl channel opening→↓ neuron firing

214

what is the clinical use of barbiturates?

sedative for anxiety, seizures, insomnia, induction of anesthesia (thiopental)

215

Barbiturate toxicity?

Respiratory and cardiovascular depression (can be fatal) • CNS depression (↑ by EtOH) • dependence • induces P450

216

when are barbiturates contraindicated?

porphyria

217

what is the treatment for barbiturate overdose?

supportive (assist respiration and maintain BP)

218

which drugs are benzodiazepines?

diazepam • lorazepam • triazolam • temazepam • oxazepam • midazolam • chlordiazepoxide • alprazolam

219

what is the mechanism of action of benzodiazepines?

facilitates GABAa action by ↑ frequency of Cl channel opening

220

effect of benzodiazepines on REM sleep?

221

t1/2 of benzodiazepines?

most have long half lives and active metabolites except for triazolam, oxazepam, and midazolam which are short acting →higher addictive potential

222

what do benzos barbs and EtOH all have in common?

all bind GABAa receptor= ligand gated Cl channel

223

clinical use of benzodiazepines?

anxiety • spasticity • status epilepticus • detoxification • night terrors • sleepwalking • general anesthesia (amnesia, muscle relaxation) • hypnotic

224

which benzos can be used for status epilepticus?

lorazepam and diazepam

225

toxicity of benzodiazepines?

dependence • additive CNS depression FX with EtOH • less risk of respiratory depression and coma than with barbiturates

226

treat overdose of benzodiazepines with what?

flumazenil (competitive inhibitor at benzodiazepine GABA receptor)

227

which drugs are the nonbenzodiazepine hypnotics?

Zolpidem (Ambien) • zalephon • eszopiclone

228

mechanism of nonbenzodiazepine hypnotics?

act via the BZI subtype of the GABA receptor

229

how are effects of Zolpidem, zalephon, and eszopiclone reversed?

flumazenil

230

what is the clinical use of zolpidem and other non benzodiazepine hypnotics?

insomnia

231

toxicity of zolpidem, zalephon, eszopiclone?

ataxia • HA • confusion

232

duration of non BZD hypnotics?

short because of rapid liver metabolism

233

difference between zolpidem and older sedative hypnotics?

cause only modest day after psychomotor depression and few amnestic effects • lower dependence risk than benzos

234

what is necessary for a drug to work on the CNS?

lipid soluble (cross BBB) • or • be actively transported

235

features of anesthetics with ↓ solubility in blood?

rapid induction and recovery times

236

features of anesthetics with ↑ solubility in lipids?

↑ potency= 1/MAC

237

what is MAC?

minimal alveolar concentration at which 50% of the population is anesthetized

238

MAC varies with what?

age

239

solubility properties of N2O?

↓ blood and lipid solubility, and thus fast induction and low potency

240

solubility properties of halothane?

↑lipid and blood solubility, and thus high potency and slow induction

241

which drugs are inhaled anesthetics?

halothane • enflurane • isoflurane • sevoflurane • methoxyflurane • nitrous oxide

242

what is the mechanism of inhaled anesthetics?

unknown

243

what are the effects of inhaled anesthetics?

myocardial depression • respiratory depression • nausea/emesis • ↑ cerebral blood flow (↓cerebral metabolic demand)

244

toxicity of halothane?

hepatotoxicity

245

toxicity of methoxyflurane?

nephrotoxicity

246

toxicity of enflurane?

proconvulsant

247

which inhaled anesthetics carry risk of malignant hyperthermia?

all but N2O; rare life threatening inherited susceptibility

248

toxicity unique to N2O?

expansion of trapped gas in a body cavity

249

what are the intravenous anesthetics?

Barbiturates • Benzodiazepines • Arylcyclohexylamines (Ketamine) • Opioids • Propofol

250

MC barbiturate IV anesthetic?

Thiopental

251

PK of thiopental as IV anesthetic?

high potency, high lipid solubility, rapid entry into brain

252

thiopental is used as an IV anesthetic for what?

induction of anesthesia and short surgical procedures

253

effect of thiopental as IV anesthetic is terminated by what?

rapid redistribution into tissues (MSK + Fat)

254

effect of IV thiopental on cerebral blood flow?

↓cerebral blood flow

255

which IV benzodiazepine is most common anesthetic used for endoscopy?

midazolam

256

how is midazolam used as IV anesthetic?

adjunctively with gaseous anesthetics and narcotics

257

risk of IV midazolam for anesthesia?

may cause severe post/op respiratory depression, ↓BP and amnesia

258

what are arylcyclohexylamines like ketamine?

PCP analogs that act as dissociative anesthetics

259

PD of IV ketamine in anesthesia?

blocks NMDA receptors

260

effect of IV ketamine on Cardiovascular system?

cardiovascular stimulant

261

congitive effects of arylcyclohexylamines?

cause disorientation, hallucination, and bad dreams

262

effect of arylcyclohexylamines on cerebral blood flow?

↑ cerebral blood flow

263

use of IV opioids in anesthesia?

morphine, fentanyl used with other CNS depressants during general anesthesia

264

propofol is used for what?

sedation in ICU • rapid anesthesia induction • short procedures

265

PD effects of IV propofol?

potentiates GABAa

266

difference in side effects between propofol and thiopental?

propofol has less postoperative nausea than thiopental

267

what are the local anesthetic esters?

procaine • cocaine • tetracaine

268

what are the aminde local anesthetics?

lidocaine • mepivacaine • bupivacaine

269

MOA of local anesthetics?

block Na+ channels by binding to specific receptors on inner portion of channel

270

local anesthetics preferentially bind to what?

activated Na+ channels, so most effective in rapidly firing neurons

271

PK of 3° amine local anesthetics?

penetrate membrane in uncharged form, hen bind to ion channels as charged form

272

Local anesthetics can be given as what combination?

can be given with vasoconstrictors (epi) to enhance local action= • ↓bleeding, ↑anesthesia by ↓systemic concentration

273

what happens when you use an alkaline anesthetic in infected tissue?

in acidic tissue, alkaline anesthetics are charged and cannot penetrate membrane effectively →need more anesthetic

274

what is the order of nerve blockade by local anesthetics?

small diameter myelinated > small unmyelinated> large myelinated fibers > large unmyelinated

275

what is the order of loss of sensation in local anesthesia?

1 pain • 2 temperature • 3 touch • 4 pressure

276

what is the clinical use of local anesthetics?

minor surgical procedures, spinal anesthesia. If allergic to esters, give amides

277

toxicity of local anesthetics?

CNS excitation, severe cardiovascular toxicity (bupivacaine), HTN, arrhythmia (cocaine)

278

neuromuscular blocking drugs are used for what?

muscle paralysis in surgery or mechanical ventilation. selective for motor vs autonomic nicotinic receptor

279

prototypical depolarizing neuromuscular blocker?

succinylcholine

280

MOA of succinylcholine?

strong ACh receptor agonist; produces sustained depolarization and prevents muscle contraction

281

steps in reversal of succinylcholine blockade?

Phase I (prolonged depolarization) no antidote. block potentiated by cholinesterase inhibitors • Phase II (repolarized but blocked) antidote consists of cholinesterase inhibitors

282

complications of succinylcholine use?

hypercalcemia • hyperkalemia • malignant hyperthermia

283

what are the nondepolarizing neuromuscular blockers?

tubocurarine • atracurium • mivacurium • pancuronium • vecuronium • rocuronium

284

MOA of nondepolarizing neuromuscular blockers?

competitive antagonists- compete with ACh for receptors

285

how do you reverse blockade by nondepolarizing neuromuscular blockers?

neostigmine • edrophonium • and other cholinesterase inhibitors

286

what is the MOA of dantrolene?

prevents the release of Ca++ from the sarcoplasmic reticulum of skeletal muscle

287

what is the clinical use of dantrolene?

used in the treatment of malignant hyperthermia and neuroleptic malignant syndrome

288

what are the strategies for the treatment of Parkinson's disease?

1. Dopamine agonists • 2. ↑dopamine • 3. prevent dopamine breakdown • 4. Curb excess cholinergic activity

289

what is the mnemonic for the treatment of Parkinson's?

BALSA • Bromocriptine • Amantadine • Levodopa • Selegiline • Antimuscarinics

290

what are the dopamine agonists used for Parkinson's?

Bromocriptine (ergot) • pramipexole • ropinirole (non-ergot) • Non ergot are preferred

291

what are the agents used to ↑dopamine in Parkinson's?

Amantadine (may ↑dopamine release) • L-dopa/carbidopa

292

Amantadine is also used for what?

antiviral against influenza A and rubella

293

toxicity of Amantadine?

ataxia

294

MOA of Ldopa?

converted to DA in CNS

295

what agents prevent dopamine breakdown in Parkinson's?

Selegiline • entacapone • tolcapone

296

MOA of selegiline?

selective MAO type B inhibitor which preferentially metabolized dopamine over NE and 5HT

297

MOA of entacapone, tolcapone?

COMT inhibitors- prevent Ldopa degradation

298

which agents curb excess cholinergic activity in Parkinson's?

Benztropine

299

MOA of benztropine?

Antimuscarinic; • improves tremor and rigidity but has little effect on bradykinesia

300

difference between Ldopa and DA?

L dopa can cross BBB and is converted by dopa decarboxylase in the brain to DA

301

MOA of carbidopa?

a peripheral decarboxylase inhibitor, is given with Ldopa to ↑bioavailability of Ldopa in the brain and to limit peripheral side effects

302

toxicity of Ldopa/carbidopa?

arrhythmia from increased peripheral formation of catecholamines • long term use can lead to dyskinesia following administration, akinesia between doses

303

clinical use of selegiline?

adjunctive agent to L dopa in Tx of Parkinsons

304

toxicity of selegiline?

may enhance adverse effects of Ldopa

305

what are the Alzheimer's drugs?

Memantine • Donepezil, galantamine, rivastigmine

306

MOA of memantine?

NMDA receptor antagonist; helps prevent excitotoxicity

307

toxicity of memantine?

dizziness • confusion • hallucinations

308

MOA of donepezil, galantamine, rivastigmine?

acetylcholinesterase inhibitors

309

toxicity of AChE inhibitors in AD?

nausea • dizziness • insomnia

310

what are the neurotransmitter changes in Huntington's disease?

↓GABA • ↓ACh • ↑DA

311

what are the treatments for Huntingtons?

Terbenazine and reserpine • Haloperidol

312

MOA of terbenazine and reserpine in huntingtons?

inhibit VMAT; limit DA vesicle packaging and release

313

MOA of haloperidol for huntingtons?

DA receptor antagonist

314

MOA of sumatriptan?

5HT1B/1D agonist- • inhibits trigeminal nerve activation • prevents vasoactive peptide release • induces vasoconstriction

315

t1/2 of sumatriptan?

<2h

316

clinical use of sumatriptan?

acute migraine • cluster HA attacks

317

toxicity of sumatriptan?

coronary vasospasm (CI in patients with CAD or prinzmental's angina) • mild tingling