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Flashcards in Neurology Deck (176):
1

Neural tube development

1) Notochord induces ectoderm to differentiate into neuroectoderm and form neural plate
2) Neural plate gives rise to neural tube and neural crest cells
3) Notochord becomes nucleus pulposus of intervertbral disc

Alar plate- dorsal, sensory
Basal plate- ventral, motor

2

Regionalization of the brain

PRimary vesicles: prosencephalon (forebrain), mesencephalon (midbrain), rhombencephalon (hindbrain)

Secondary vescles
-prosencephalon -- telencephalon (cerebral hemispheres and lateral venticles) and diencephalon (thalamus and third ventricle)
-mesencephalon -- midbrain and cerebral aqueduct
rhombencephalon --metencephalon (pons and cerebellum) and myelencephalon (medulla); both contribute to fourth ventricle

3

Neuroectoderm derivatives

CNS neurons, epednymal cells that line the ventricles and make CSF, oligodendroglia, astrocytes

4

Neural crest derivatives

PNS neurons and schwann cells

5

mesoderm derivatives

microglia (hematopoietic lineage)

6

Testing for neural tube defects

Elevated AFP in maternal serum and amniotic fliud
Elevated AChE in amniotic fluid

7

Spina bifida occulta

Failure of bony spinal canal to close without any structural herniation and with dura intact. AFP is normal. Least severe neural tube defect.

8

Meningocele and Meningomyelocele

Meningocele: meninges only herniate through bony defect
Meningomyelocele: meninges and nural tissue hernate through bony defect; associated with chiari II malformation

both have risk of ascending infection
Look like plaquode on skin

9

Holoprosencephaly

Not a neural tube defect. Failure of left and right hemispheres to separate. Can be caused by sonic hedgehog mutations. Associated with Patau syndrome and FAS. Associated with cleft palate/lip, cyclopia

10

Chiari II

Hernation of cerebellar tonsils and vermis through foramen magnum. Aqueductal sternosis and hydrocephalus as result. Meningomyelocele (neural tube defect) is associatd

11

Dandy Walker malformation

Agenesis of cerebellar vermis with cystic enlargement of the fourth ventricle. Associated with hydrocephalus and spina bifida

12

Syringomyelia

Cystic cavity in spinal cord. Typicall damages corssing anterior spinal commisurral fibers leading to cape like loss of pain and temp in upper extremities. Associated with chiari I

13

Chiari I malformation

Cerebellar tonsils herniate. Associated with syringomyelia. Usually asymptomatic in childhood

14

Tongue development

1st and second branchial arches: anterior 2/3 with sensation from V3, taste from VII
3rd and 4th arches form posterior 1/3 with sensation and taste from IX and X
Motor from X (palatoglossus) and XII (all others)

15

Nissl stain

Stains RER and can be used to visualize cell bodies and dendrites of neurons. Doesn't stain axon as RER is not present: proteins are synthesized in the cell body and transported down the axon

16

Wallerian degeneration

In response to axonal injury, the nerve degenerates distal to the injury and the axon retracts proximally, allowing for regeneration if in the PNS. Regeneration occurs slowly over weeks to months.

17

Astrocytes

Functions: physical support, repair, potassium metabolism, removal of excess neurotransmitter (take up glutamate and convert to glutamine), component of BBB, reactive gliosis in response to neuronal injury, match cerebral blood flow to synaptic activity

Marker: GFAP

Derivative of neuroectoderm

18

HIV in the brain

Infect microglia, which fuse to form multinucleated giant cells in the CNS

19

Scwann cells

Each Schwann cell myelinates 1 PNS axon. Promote axonal regeneration. Derived from neural crest

20

Oligodendroglia

Myelinate axons of CNS. Each oligodendrocyte can myelinate many axons. Derived from neuroectoderm. Fried egg appearance

21

Types of sensory receptors: free nerve endings, meissner corpuscles, pacinian corpuscles, merkel discs, ruffini corpuscles

Free nerve endings: Carry pain on C fibers, temp on Adelta fibers. Located in skin and seome viscera

Meissner corpuscles: Carry fine touch and position on large myelinated fibers that adapt quickly. Found on hairless skin

Pacinian corpuscles: Carry vibration and pressure on large myelinated fibiers that adapt quickly. Found in deep skin layers, ligaments, and joints.

Merkel discs: Carry pressure, deep touch, and position on large myelinated fibers that adapt slowly. Found in fingertips and superficial skin

Ruffini corpuscles: Carry pressure information on slow adapting dendritic endings within the capsule

22

Layers of a peripheral nerve

Endoneurium: surrounds single nerve fibers
Perineurium: surround fasicle of nerve fibers
Epineurium: dense connective tissue surrounding entire nerve

23

Location of neurotransmitter synthesis: NE, DA, 5-HT, ACh, GABA

NE: locus ceruleus of the pons
Dopamine: ventral tegmentum and substantia niagra of midbrain
5-HT: Raphe nuclei in brainstem
ACh: Basal nucleus of Meynert
GABA: nucleus accumbens

24

Components of BBB

1. Tight junctions between nonfenestrated capillary endothelial cells
2. Basement membrane
3. Astrocyte foot processes

25

OVLT

Area of hypothalamus not protected by BBB that senses changes in osmolarity.

26

Area postrema

Area of hypothalamus not protected by BBB that responds to emetics

27

Supraoptic nucleus

Part of hypothalamus that makes ADH

28

PAraventricular nucleus

Part of hypothalamus that makes oxytocin

29

Hypothalamus: lateral, ventromedial, anterior, posterior, suprachiasmic nucleus

Lateral area: hunger, inhibited by leptin
Ventromedial area: Satiety, stimulated by leptin
Anterior hypothalamus: Cooling, parasympathetic
Posterior hypothalamus: Heating, sympathetic
Suprachiasmic nucleus: Circadian rhythm

30

Circadan rhythm

Controlled by suprachiasmic nucleus. Drives nocturnal release of ACTH, prolactin, melatonin, norepinephrin.

31

Effect of CNS depressants on sleep

EtOH, benzos, and barbs decrease REM sleep and delta wave sleep

32

Pathology of different sleep stages

Non-REM stage N2: bruxism (teeth grinding)
Non-REM stage N3: sleepwalking, night terrors, bed wetting

33

Thalamic nuclei

VPL: Spinothalamic tract and dorsal column relay to sensory cortex

VPM: Trigeminal and taste relat to sensory cortex

LGNL Received vision info from CNII and sends to calcarine sulcus

MGN: Reveives auditory info from sup olive and inf collicular and sends to auditory cortex

VL: Reveives motor info from basal ganglia and cerebellum and relays to motor cortex

34

Limbic system

Includes hippocampus, amygdala, fornix, mamillary bodies, and cingulate gyrus

35

Central pontine myelinolysis

Result of overly rapidly correcting hyponatremia. Results in acute paralysis, LOC, locked in syndrome

36

Pathways through basal ganglia

Excitatory: Cortical inputs stimulate striatum; striatum stimulates release of GABA which disinhibits the thalamus via GPi/SNr

Inhibitors: Cortical inputs stimulate striatum, disinhibits STN via GPe, STN stimulates GPI/SNr to inhibit thalamus.

37

Dopamine receptors

D1: stimulates excitatory pathway
D2: inhibits inhibitory pathway
both increase motion

38

Hemiballismus

Decreased activity of subthalamic nucleus decreasing GPint activity, increasing thalamic activity and causing flailing. Sudden wild flailing of 1 arm and sometimes ipsilateral leg due to damage to contralateral subthalamic nucleus

39

Athetosis

Slow writhing movements of the fingers seen with lesions to basal ganglia, such as in Huntington

40

Treatment of essential tremor

beta blcokers
primidone

41

Myoclonus

Sudden, brief, uncontrolled muscle contraction seen iwth metabolic abnormalities

42

Pathology of PD

Lewy bodies of alpha synuclein which have intracellular eosinophilic inclusions. Loss of dopaminergic neurons of substantia niagra

43

Neurotransmitters in HD

DA increased
GABA decreased
ACh decreased

44

Broca aphasia

Nonfluent aphasia with intact comprehension, impaired repetition.

Broca area in inferior frontal gyrus of frontal lobe

45

Wernicke aphasia

Fluent aphasia with impaired comprehension and repetition.

Wernicke area is in superior temporal gyrus of termporal lobe

46

Conduction aphasia

Poor repetition but fluent speech and intact comprehension

Can be caused by damage to arcuate fasciculus

47

Global aphasia

Nonfluent aphasia with impaired comprehension

48

Transcortical motor aphasia

Nonfluent, good comprehension, intact repetition

49

Transcortical sensory aphasia

Poor comprehension, fluent speech, intact repetition

50

Mixed transcortical aphasia

Nonfluent speech, poor comprehension, intanct repetition

51

Kluver Bucy syndrome

Bilateral damage to amygdalae. Disinhibited behavior with hyperphagia, hypersexuality, hyperorality. Associated with HSV-1

52

Frontal lobe lesions

Cause disinhibition, problems with concentration, orietnation, judgement, possible reemergence of primitive reflexes

53

Parietal-temporal cortex lesions

Nondominant: hemispatial neglect syndrome

Dominant: Gerstmann syndrome of agraphia, acalculia, finger agnosia, left-right disorientation

54

Reticular activating system lesions

Reduced levels of arousal and wakefulness

55

Wernicke-Korsakoff syndrome

Pathology: affects mammillary bodies

Presentation: confusion, ophthalmoplegia, ataxia, memory loss, personality changes, confabulation

56

Basal ganglia lesions

Resting tremor, chorea, athetosis

57

Cerebellar lesions

Hemisphere: Intention tremor, limb ataxia, loss of balance. Ipsilateral defects; fall toward side of lesion

Vermis: Truncal ataxia, dysarthria

58

Hippocampal lesions

Anterograde amnesia

59

Defects to paramedian pontine reticular formation vs frontal eye fields

Paramedian pontine reticular formation: eyes look away from side of lesion

Frontal eye fields: eye look toward lesion

60

Regulation of cerebral perfusion

Driven by Pco2. Po2 modulates only in severe hypoxemia. Increased Pco2 increases cerebral perfusion pressure. Decreased O2

61

Therapeutic hyperventilation

Decreases Pco2 which helps to decrease intracranial pressure in acute cerebral edema via vasoconstrtion (brain thinks it has plenty of oxygen if CO2 is low). Hypventilation in panic attacks decreases perfusion leading to fainting.

62

Cerebral perfusion pressure

CPP = MAP - ICP

So, hypotension or incresaed intracranial pressure can decrease cerebral perfusion

63

Presentation of MCA stroke

Can get contralateral paralysis of upper limb and face due to effect on motor cortex

Can get contralateral sensory loss of uppper limb and face due to effect on sensory cortex

Can get aphasia or hemineglect due to effect on ermporal lobe and frontal lobe

64

Presentation of lenticulostriate artery stroke

Affects striatum and internal capsule. Contralateral hemiparesis/hemiplegia. Often lacunar infarct secondary to unmanaged hypertension

65

Presentation of anterior spinal artery stroke

Affects lateral corticospinal tract: contralateral hemiparesis of upper and lower limbs

Affects medial lemniscus: loss of contralateral proprioception

Affects caudal medulla: ipsilateral hypoglossal dysfunction with tongue deviating ipsilaterally

66

Presentation of PICA stroke

Affects lateral medulla: vomiting, vertigo, nystagmus due to cerebellar dysfunction and effect on vestibular nuclei. Decreased pain and temp sensation from ipsilateral face, contralateral body due to effect on lateral spinothalamic tract. Dysphagia and hoarseness due to effect on nucleus ambiguus. Ipsilateral horner syndrome due to effect on sympathetic fibers

67

Presentation of AICA stroke

Affects lateral pons including middle and inferior cerebellar peduncles. Presents with vomiting, vertigo, nystagmus, face paralysis, ataxia, dysmetria

68

Presentation of PCA stroke

Affects occipital cortex and visual cortex. Contralateral hemianopia with macular sparing

69

Presentation of basilar artery stroke

Locked in syndrome. Preserved consciousness and blinking with quadriplegia and loss of mouth, face, tongue movements

70

Presentation of anterior communicating artery stroke

Most often due to aneurysm. Presents with visual field defect

71

Presentation of posterior communicating artery stroke

Saccular aneurysms. CNIII palsy.

72

Saccular aneurysms

Also called berry aneurysms. Occur at bifurcations of circle of willis, most commonly junction of ACA and ant comm a. Rupture leads to SAH or hemorrhagic stroke. May compress optic chiasm.

73

Diseases associated with saccular aneurysms

ADPKD, Ehlers-danlos

74

Charcot-Bouchard microaneurysm

Associated with chronic HTN. Affects small vessels of basal ganglia and thalamus

75

Central post-stroke pain syndrome

Neuropathic pain due to thalamic lesions. Parasthesias followed by allodynia and dysesthesia

76

Epidural hematoma

Caused by middle meningeal artery rupture secondary to fracture. Classic lucid interval followed by expansion and transtentorial herniation with CNIII palsy. Biconvex blood collection that doesn't cross suture lines, can cross falx, tentorium

77

Subdural hematoma

Caused by rupture of bridging veins. Slow venous bleeed over time. Seen in eldery, alcoholics, blunt trauma, shaken baby. Crescent shaped hemorrhage that crosses suture lines. Cannot cross tentorium

78

SAH

Caused by rupture of an aneurysm or AVM. Rapid ime course. Worst headache of life. Bloody or yellow spinal tap. Risk of vasospasms 2-3 days afterward due to blood breadown and rebleed

79

Intraparenchymal hemorrhage

Associate dwith systemic HTN or amyloid angiopathy, vascultitis, neoplasm. Basal ganglia and internal capsule are most common locations

80

Ischemic brain diesease

irreversible damage 5 mins of hypoxia. Hippocampus, neocorex, and cerebellum most vulnerable.

Imaging: noncontrats CT to exclude hemorrhage. Will detect ischemic changes in 6-24 hours. Diffusion-weighted MRI can detect ischemia much sooner

81

Histologic changes seen after ischemic stroke

12-48 hrs: red neurons
24-72 hrs: necrosis and neutrophils
3-5 days: macrophages/microglia
1-2 weeks: reactive gliosis and vascular proliferation
over 2 wks: glial scar

82

CSF flow

Made by ependymal cells of choroid plexus. Flows from lateral ventricles through R and L interventricular foramina of monroe into 3rd ventricle, through cerebral aqueduct to 4th ventricle, into subarachnoid space through foramina of luschka (lateral) and foramen of magendie (medial). Reabsorbed by arachnoid granulations. Drains into dural venous singuses

83

Idiopathic intracranial HTN

Also called pseudotumor cerebri. Increased ICP without apparent cause on imaging. Presents with headaches and diplopia without mental status change. Papilledema present. Increased opening pressure on LP.

Risk factors: woman of childbearing age, vitamin A excess, danazol

Treatment: weight los, acetazolamide, topiramate

84

Normal pressure hydrocephalus

Idiopathic condition seen in elderly. CSF pressure elevated episodically. Expansion of ventricles, distorting fibers of corona radiata. Wet, wobbly, and wacky: urinary incontinence, ataxia, cognitive dysfunction

85

Ex vacuo ventriculomegaly

Appearance of increased CSF on imaging due to decreased brain tissue. Normal ICP

86

Spinal nerve naming

C1-C7 exit above corresponding vertebra. C8 exits below C7. Rest exit below their corresponding vertebra

87

Vertebral disc herniation

Nucleus pulposus herniates through annulus fibrosus.

88

Lower extension of spinal cord

Adults: lower border of L1-L2 vertebra. Subarachnoid space to loer border of S2. LP performed between L3/L4 or L4/L5

89

Medial lemniscus

Carries sensory fibers from the nucleus gracilis and cuneatus to LGN

90

Poliomyelitis

Destruction of anterior horns. LMN lesions only (flaccid paralysis). Replicates in oropharynx and sm intestine; then spreads to CNS by blood stream

CSF: increased WBCs and slight increased protein

91

Spinal muscular atrophy

congenital degeneration of anterior hormones. LMN lesions only (flaccid paralysis). Floppy baby with tongue fasciculations. AR inheritance

92

Multiple sclerosis effect on spinal cord

Demyelination mostly of white matter in cervical region. Random and asymmetric lesions

93

Riluzole

Glutamate antagonist used to treat ALS

94

Tabes dorsalis

Caused by tertiary syphilis. Degeneration of dorsal columns and nerve roots resulting in impaired sensation and proprioception and poor coordination. Absent DTRs, pos romberg

95

Vitamin B12 def - effect on spinal cord

Subacute combined degeneration: demyelination of dorsal columns, lateral corticospinal tracts, spinocerebellar tracts resulting in ataxic gait, paresthesia, impaired pos and vibration sense

96

Friedreich ataxia

AR GAA repeat on chromosome 9. Gene encodes iron binding protein frataxin. Leads to impairment of mitochondrial function.

Degeneration of spinal tracts resultingin weakness, loss of DTRs, vibratory sense, and proprioception.

Associated with diabetes and hypertrophic cardiomyopathy. Also kyphoscoliosis

97

Brown Sequard syndrome

Hemisection of cord. If above T1 can cause Horner syndrome as well as spinal cord findings

98

Key dermatomes: C2, C3, C4, T4, T7, T10, L1, L4, S2, S3, S4

C2: posterior half of skull cap
C3: high turtleneck shirt
C4: low collar shirt
T4: nipple
T7: xiphoid process
T10: umbilicus
L1: inguinal ligament
L4: kneecap
S2, S3, S4: erection and sensation of penis and anus

99

Pineal gland

Located above the superior colliculi. Responsible for melatonin secretion and circadian rhythms

100

Supeiror and inferior colliculi

Superior: conjugate vertical gaze
Inferior: auditory function

101

Locations of cranial nerve nuclei

Midbrain: III and IV
Pons: V, VI, VII, VIII
Medulla: IX, X, XII
Spinal cord: XI

Latearl nuclei are sensory, originating from alar plate
Medial nuclei are motor, originating from basal plate

102

Optic canal: what travels through

CNII, ophthalmic artery, central venous vein

103

Superior orbital fissure: what passes through

CNIII, IV, V1, VI (all nerve to eye except optic) + opthalmic vein and sympathetic fibers

104

Foramen rotundum

Carries CN V2

105

Foramen ovale

Carries CN V3

106

Foramen spinosum

Holds middle meningeal artery

107

Internal auditory meatus

Carries CN VII and VIII

108

Jugular foramen

Carries CN IX, X, XI, jugular vein

109

Hypoglossal canal

Carries CN XII

110

Foramen magnum

Carries spinal roots of CN XI, brainstem, vertebral arteries

111

Function of CN IV and XI

IV (trochlear) innervates superior oblique
VI (abducens) innervates lateral rectus

112

Sensation of tongue

Somatosensory for anterior 2/3: CNV
Taste for anterior 2/3: CNVII
Taste and somatosensory for posterior 1/3: CNIX
Taste from epiglottic region: CNX

113

Carotid and aoritc body monitoring

CNIX monitors carotid body and sinus chemo and baroreceptors
CNX monitors aortic arch chemo and baroreceptors

114

Nucleus solitarius

Visceral sensory information for CNVII, IX, X - taste, baroreceptors, gut distention

115

Nucleus ambiguus

Motor information for pharynx, larynx, upper esophagus. CNIX, X, XI

116

Dorsal motor nucleus

Autonomic fibers of CNX to heart, lungs, upper GI tract

117

Gag reflex

Afferent: IX
Efferent: X

118

Cavernous sinus

Collection of venous sinuses on either side of pituitary. Blood from eye and superficial cortex drains into cavernous sinus which drains into internal jugular vein.

CN III, IV, V1, VI pass through to get to orbit

119

Cavernous sinus syndrome

Ophthalmoplegia, decreased corneal sensation, Horner syndrome due to pituitary tumor mass effect, fistula, cavernous sinus thrombosis affecting nerves that pass through

120

Tonotopy of basilar membrane

Low freq heard at apex which is wide and flexible
High freq heard at base of cochlea which is thin and rigid

121

Test results for conductive vs senorineural hearing loss

Conductive hearing loss: Rinne test abnormal with bone greater than air. Weber test localizes to affected ear

Sensorineural hearing loss: Rinne test normal wiht air greater than bone conduction. weber localizes to unaffected ear

122

Noise induced hearing loss

Damages hair cells. Leads to loss of high freq hearing loss first

123

Cholesteatoma

Overgrowth of desquamated keratin debris within middle ear. May errode ossicles and mastoid air cells leading to conductive hearing loss

124

UMN vs LMN lesion of face

UMN: causes contralateral paralysis of the face. upper face is spared because it gets bilateral UMN innervation

LMN: causes ipsilateral paralysis of upper and lower face

125

Muscles of mastication

Masseter, temporalis, and medial pterygoid close the jaw

Lateral pterygoid opens

126

Aqueous humor pathway

Produrced by ciliary epithelium. Collected by trabecular meshwork, then goes into canal of schlemm to drain

127

Refractive errors: hyperopia, myopia, astigmatism, presbyopia

Hyperopia: eye too short; light focused behind retina
Myopia: eye too long; light focused in front of retina
Astigmatism: abnormal curvature of cornea
Presbyopia: age-related impaired acommodation due to decreased lens elasticity

128

Glaucoma

Opitc disc atrophy with cupping. Elevated IOP, progressive peripheral vision loss

129

Open angle glaucoma

Painless and more common. Associated with age, african america, famiy history. Can be secondary to blocked trabecular meshwork with WBCs, RBCs, retinal elements

130

Tetrodotoxin

Toxin found in puffer fish. Binds to NA+ channels, inhibiting influx

131

Morphine effect on ion channels

Binds to mu receptors and causes G protein coupled acivation of K+ channels to increase K+ efflux, hyperpolarizing post-synatpic neurons and terminating pain transmission

132

Kinesin

MT associated motor protein that does anterograde transport of intracellular vesicles and organelles toward plus end of MTs.

133

Valproate during pregnancy

Increases risk of neural tube defects because inhibits folic acid absorption

134

Length constant vs time constant

Length constant: How far long an axon an impulse can propagate. Increased by myelin so that conduction occurs faster.

Time constant: How long it takes for a change in membrane potential to occur. Reduced by myelination so that conduction occurs faster.

135

POMC

Polypeptide precursor that goes through enzymatic modification to produce beta endorphins, ACTH, and MSH

136

Tetrahydrobiopterin

BH4. Cofactor in synthesis of serotonin, DOPA, and tyrosine

137

CSF findings in MS

Increased protein in CSF - oligoclonal bands diagnostic

138

Treatment of MS

Disease modifying therapies: beta-interferon, natalizumab

Acute flares: IV steroids

139

Treatment of Guillan Barre

Respiratory support. Plasmapheresis. IVIG

140

Acute disseminated encephalomyelitis

Multifocal periventricular inflammation and demyelination after infection or certain vaccinations. Commonly seen after measles or VZV

141

Charcot-Marie-Tooth disease

Progressive hereditary nerve disorders due to defective protein production. AD inheritance. Associated with scoliosis and foot deformities

142

Krabbe disease

AR lysosomal storage disease due to def of galactocerebrosidase. Causes galactocerebroside to build up and destroy myelin. Presents with peripheral neuropathy, developmental delay, optic atrophy, globoid cells

143

Metachromatic leukodystrophy

AR lysosomal storage disease. Arylsulfatase A def. Central and peripheral demyelination with ataxia and dementia

144

Progressive multifocal leukoencephalopathy

Demyelination of CNS due to oligodendrocyte destruction. Associated with JC virus - seen in AIDS patients. Radpily progressive and fatal.

145

Adrenoleukodystrophy

X-linked genetic disorder. Disupted metabolism of VLCFA causing build up in NS, adrenal, testes.

146

Positional testing for nystagmus

Delayed horizontal nystagmus suggests peripheral (inner ear) vertigo

Immediate nystagmus in any direction suggests central vertigo

147

Sturge-Weber syndrome

Congenital anomaly of neural crest derivatives due to acivating GNAQ mutation. Affects capillaries leading to port-wine stain on face. Ipsilateral leptomeningeal angioma causes seizures. Intellectual disability. Episcleral hemangioma leads to elevated IOP and early onset glaucoma

148

Tuberous sclerosis

Hamartomas in CNS and skin.
Angiofibromas
Mitral regurg
Ash-leaf spots
Cardiac rhabdomyoma
mental retardation
renal angiomylolipoma
seizures
shagreen patches
Autosomal dominant inheritance

149

Cancers seen with von hippel lindau

hemangioblastomas of retina, brain stem, cerebellum, and spine
angiomatosis
bilateral renal cell carcinoma
pheochromocytoma

150

Glioblastoma multiforme pathology

Found in cerebral hemispheres and can cross the corpus callosum. Stains positive for GFAP. Pseudopalisading, pleomorphic tumors cells: tumor cells border areas of necrosis and hemorrhage

151

Meningioma presentation and pathology

Presentation: Seizures or focal neurologic signs due to compression of brain tissue

Pathology: spindle cells in whorled paterns; psammoma bodies

152

Hemangioblastoma

Associated with VHL syndrome. Usually cerebellar. Can make EPO leading to polycythemia.

153

Schwannoma: location and tumor marker

Found at cerebellopontine angle. S-100 positive.

154

Oligodendroglioma

Slow growing, usually in frontal lobes. Fried egg cell appearance. Often calcified

155

Pilocytic astrocytoma

Well circumscribed posterior fossa tumor of childhood. GFAP +. Benign with good prognosis. Rosenthal fibers

156

Medulloblastoma histology

Homer-Wright rosettes. Solid small blue cells

157

Ependymoma

Ependymal cell tumor found in 4th ventcile. Can cause hydrocephalus. Poor pronosis. Perivascular rosettes on histology

158

Craniopharyngioma

Benign tumor of childhood in sella turcica. Presents with bitemporal hemianopia. Derived from Rathke pouch remnants. Commonly calcified

159

Cingulate herniation

Cingulate gyrus herniates under falx cerebri. Can compress ACA

160

Transtentorial herniation

Can displace brain stem leading to duret hemorrhages; usually fatal

161

Uncal hernation

Uncus herniates downward and compresses CNIII and PCA

162

Cerebellar tonsilar herniation

Herniates into foramen magnum. Can compress brainstem resulting in coma and death

163

MOA of opioids

Agonize opioid recetpors. Open K+ channels and close Ca++ channels to reduce synaptic transmission. Inhibit release of ACh, NE, 5-HT, glutamate, substance P

164

Butorphanol

MOA: kappa opioid agonist, mu opioid partial agonist
Less resp depression than full opioid agonist
Can cause withdrawal in someone also taking full agonist due to competition at mu receptor

165

Tramadol

MOA: weak opioid agonist; inhibits 5-HT and NE reuptake
Toxicity: decreased seizure threshold, serotonin syndrome

166

Ethosuximide toxicity

Itching, stevens johnson syndrome

167

Phenytoin: MOA, pharmacokinetics, side effects, use

MOA: Increases Na+ channel inactivation
Kinetics: 0 order kinetics
Side effects: gingival hyperplasia, P450 induction, stevens johnson
Use: First line for tonic-clonic seizures and prophylaxis of status epilepticus; can be used for everything except absence

168

Carbamazepine: MOA, side effects, use

MOA: Increases Na+ channel inactivation
Side effects: agranulocytosis and aplastic anemia, teratogenic, P450 induction, SJS
Use: First line for partial seizures and tonic-clonic seizures, first line for trigeminal neuralgia

169

Valproic acid: MOA, side effects, use

MOA: Increases Na+ channel inactivation, increases GABA
Side effects: hepatotoxicity, neural tube defects
Use: First line for tonic clonic seizures, effective against all seizure types. Myoclonic seizures, bipolar

170

Gabapentin: MOA, side effects, use

MOA: inbhits VG Ca++ channels
Side effects: sedation and ataxia
Use: Partial seizures, peripheral neruopaty

171

Phenobarbitol for seizures: MOA, side effects, use

MOA: Increases GABAa action
Side effects: sedation, tolerance and dependence, resp depression, P450 induction
Use: First line in neonatal seizures

172

Topiramate: MOA, side effects, use

MOA: blocks Na+ channels, increases GABA
Side effects: Sedation, mental dulling
Use: Partial and tonic-clonic seizures. Migraine prophylaxis

173

Lamotrigine

MOA: blocks VG Na+ channels
Side effects: SJS
Use: All seizure types, including absence

174

Levetiracetam use

Partial and tonic-clonic seizures

175

Tiagabine MOA and use

Inhibits GABA reuptake. Used for partial seizures

176

Vigabatrin

Increases GABA. Used for partial seizures