Neuro Flashcards
cerebral aqueduct derives from
mesencephalon (midbrain)
neural tube defect: anomaly, cause, signs
Anomaly: persistant connection between amnion and spinal canal.
Cause: low folate preg
Signes: elevated alpha-fetoprotein, acetylcholinesterase in amniotic
spina bifida occulta
failure of bony spine to close, no herniation, meninges intact, tuft of hair over dimple
meningocele
unclosed bony spine with herniation of the meningies
meningomyelocele
unclosed bony spine plus herniation of both meningies and spine
anencephaly
no forebrain, frog like appearance, polyhydramnios due to no swallow center, associated with maternal diabetes (folate reduces risk)
holoprosencephaly
failure of hemispheres to seperate, cleft lip/palate, cyclopia. due to HH defect
Arnold-Chiari Malformation
cerebellar tonsillar and vermian herniation from foramen magnum. aqueductal stenosis and hydrocephalus. associated with thoracic myelomeningocele.
Dandy-Walker formation
agenesis of cerebellar vermis, cystic enlargement of 4th ventricle, hydrocephalus and spina bifida
Syringomyelia
cystic enlargement of central spinal canal causeing spinothalamic tract damage -> cape-like loss of pain and temp (fine touch ok). associated with chiari formation.
tongue development origins
front 2/3 is 1st branchial arch, back 1/3 is 3rd and 4th arches.
tongue innervation
Taste: 7, 9 , 10 (solitary)
Pain: 5 (3rd), 9, 10
Motor: 12
wallerian degeneration
damage axon, degen distal/ retract proximal
astrocyte marker
GFAP
cells that fuse under HIV and grow when damage occurs
microglia
disease that destroys oligodendrocytes
MS
disease that destroys schwann cells
guillain-barre
ringing in the ear cancer
acoustic neuroma, schwann cells of the CN 8.
Free nerve ending sense
Pain temp
Meissner corpuscles
Fine touch
Pacinian corpuscles
Vibration, pressure
Merkels discs
Pressure, deep touch
Norepinephrine : Change in neuro disease and location of synthesis
High in anxiety, low in depression. Locus ceruleus (pons)
Dopamine: Change in neuro disease and location of synthesis
High in schizophrenia, low in Parkinson’s and depression. Ventral tegmentum, SNc (midbrain)
5-HT
Low in anxiety and depression. Raphe nucleus (pons)
Acetyl Choline: Change in neuro disease and location of synthesis
Low in Alzheimer’s and huntingtons, high in rem sleep. Basal nucleus of meynert.
GABA. Change in neuro disease and location of synthesis
Low in anxiety and huntingtons. Nucleus accumbens
three components of BBB
tight junctions of endothelials, basement membrane, astrocyte foot processes
areas where BBB is broken (and how it is opened)
Opened due to fenestrated endothelial cells. Area postrema- vomit after emetics/chemo, OVLT- osmotic sensing, neurohypophysis - to secrete ADH
Hypothalamus functions
TAN HATS: Thirst/water balance, Adenohypophysis (ant pituitary), Neurohypophysis (releases hormones), Hunger, Autonomic regulation, Temperature, Sexual urges
Lateral Area of Hypothalamus
hunger
Ventromedial area of hypothalamus
satiety
anterior hypothalamus
cooling/parasymp
posterior hypothalamus
heating/symp
suprachiasmatic
circadian rhythem
the one sense which doesn’t route through thalamus
olfaction
VPL Thalamus
. Body Feeling.
VPM thalamus
Face feeling and taste
LGN thalamus
Vision
MGN thalamus
hearing
VL
Motor
Limbic System
5 F: Feeding, Fleeing, Fighting, Feeling, Fucking
Lateral Cerebellum
coordination of ipsilateral extremities (fall towards lesion)
Medial Cerebellum
balance/truncal coordination
causes of hemiballismus
contralateral subthalamic nucleus lesion due to stroke
essential tremor treatment
ethanol (self treatment), beta blockers, primidone
essential tremor vs parkinsons
essential occurs with movement, “resting tremor” is with parkinsons
effects of dopamine in basal ganglia (D1 vs D2)
Dopamine binds D1 to stimulate excitatory and D2 to inhibit inhibitory
Lewy Bodies
intracellular alpha-synuclein inclusions seen in parkinsons
parkinsons signs
TRAP: tremor (resting), Rigidity, Akinesia, Postural Instability
Huntingtons genetics
Autosomal dominant with anticipation. CAG repeat expansions.
Huntingtons pathophys
Atrophy of striatal nuclei, caudate lose of ACh and GABA, Neuronal death via NMDA-R binding and glutamate toxicity.
Amygdala lesion
Kluver-Bucy syndrome: hyperorality, hypersexuality, disinhibited behavior, associated with HSV-1.
reemergence of primitive reflexes
frontal lobe lesions
spatial neglect syndrome
lesions in parietal lobe cause agnosia of contralateral side of the world
reticular activating system lesion
midbrain lesion causes loss of arousal/wakefulness
Mammillary body degeneration
Wernicke-Kofsakoff syndrome: confusions, ophthalmoplegia, ataxia, memory loss (anterograde and retrograde), confabulation, personality changes.
Due to thiamine deficency (b1) and excess ethanol use. Can be triggered by glucose.
anterograde amnesia
no new memories, hippocampal lesion
Central pontine myelinolysis
Locked In Syndrome: acute paralysis, dysarthria, dysphagia, diplopia. Due to massive demyelination in pons. Iatrogenic or rapid resuscitation of Na levels.
Brocas Aphasia
Can comprehend but cant speak. Inferior frontal gyrus of frontal lobe.
Wernickes Aphasia
Can speak but cant comprehend. Superior temporal gyrus of temporal lobes.
Conduction aphasia
cant repeat phrases. arcuate fasiculus
what regulates blood flow in the brain
pCO2. pO2 only in very extreme conditions
Mca stroke
Motor/sense face and upper limb
Aphasia of both wernickes and brocas
ACA stroke
Motor/sensory legs
Lateral striate artery
Lacunar infarcts secondary to hypertension. Contralateral hemiparesis/hemiplegia
ASA
Lateral corticospinal tract: contralateral lower limb hemiparesis
Medial lemniscus: down contralateral proprioceprion
Caudal medulla-hypoglossal nerve: ipsilatetal hypoglossal dysfunction.
Commonly bilateral
PICA stroke
Wallenberg Syndrome due to nucleus ambiguous effects- hoarseness and dysphagia. All of lateral medulla gone- vomiting, vertigo, pain/temp, gag reflex
AICA stroke
Lateral pons gone: facial droop.
Basically a lot of the cranial nerves are gone so decreased lacrimation, taste, corneal reflex, ipsilatetal hearing, ipsilatetal horners.
PCA stroke
Contralateral hemianopia with macular sparing
AComm stroke
Saccular aneurysm: visual field defects
PComm lesion
Also saccular aneurysm. CN3 palsy down and out eye with ptosis and dialation
Barry aneurysm association and risk
Associated with autosomal dominant polycystic kidney disease, ehler danlos, marfans
Risks include hypertension advanced age and race(black)
Rupture berry aneurysm
Subarachnoid hemorrhage
Bitemporal hemianopia
Compression of optic chiasm by berry aneurysm
Charcot Bouchard microaneurysm
Chronic hypertension, small vessel in basal ganglia and thalamus
Rupture of medial meningeal artery
epidural hematoma
epidural hematoma: vessel, symptoms, CT
medial meningeal artery (temporal bone fracture), rapidly developing with a lucid interval, CNIII plasy, CT is lense-shapped hematoma
subdural hematoma
bridging vein rupture, slow developing (vein), old/baby/alcoholics, crescent-shaped hemorrage that crosses suture lines, midline shift
subarachnoid hemorrhage
ruptured aneurysms or ateriovenous malformations. worste head ache of my life, exremely rapid loss of consciousness, bloodly LP
subarachnoid hemorrhage risk 2-3 day later
vasospasm (treat with nimodipine)
Intraparenchymal hemorrhage
hypertensive hemorrhage as well as amyloid angiopathy, vasculitis. Charcot-Bouchard’s are one type.
How long till ischemic brain injury and where?
5 mins and most vulnerable is hippocampus, neocortex, cerebellum, and watershed areas.
ischemic brain injury histology timeline
red dead neurons 12-48hrs, necrosis + neutrophils 24-72hrs, macrophages 3-5 days, reactive gliosis + vascular proliferation 1-2 weeks, glial scar after two weeks
Ischemic stroke risks
a fib, carotid dissection, patent foramen ovale, endocarditis, hypertension.
Transient ischemic attack
brief reversible focal neurological dysfunction without an infarction. due to focal ischemia (vasospasm)
CSF Flow
Ependymal cells of choroid plexus -> lateral ventricle -> foramin of monro -> 3rd vent -> cerebral aqueduct -> 4th vent -> Luschka (lateral)/Magendie (medial) foramina -> subarachnoid space -> arachnoid granulations -> superior sagittal sinus
communicating hydrocephalus
due to decreased CSF absorption -> high ICP
normal pressure hydrocephalus
Wet, wobbly, wacky (incontinency, ataxia, cognitive dysfunction). due to expanded ventricle space but normal pressure
hydrocephalus ex vacuo
high CSF due to brain atrophy (alzheimers, HIV, Picks) normal pressure and ventricles
number of spinal nerves in each section
8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal. 31 total
where do nerve roots exit?
C1-7 exit above their vertebra, the rest exit below.
disc herniation
nucleus pulposus herniates through anulus fibrosus at L4-L5 or L5-S1
where does spinal chord end?
L1-L2
spine front and center tract
Anterior spinothalamic tract (crude touch, pressure)
spine sides tract
Lateral corticospinal tract (motor)
spine back side
lateral spinothalamic (pain temp)
spine back center
dorsal column (pressure, vibration, touch, proprioception)
dorsal column structure
pressure, vibration, fine touch, proprioception. dorsal root ganglia, ipsilateral spine ascending, medulla 1st synapse then 2nd neuron crosses over to VPL 2nd synapse
spinothalamic tract structure
pain, temp, crude touch, pressure. 1st nerve enters spine, synapse 1 in ipsilateral gray matter, 2nd neuron crosses over immiedately then ascends to VPL
Lateral corticospinal tract
motor. 1 neuron in motor cortex crosses over in medulla then decends, then synapse 1 in anterior horn, 2 neuron leaves spine (no third neuron)
What does poliomyelitis attack?
LMN disease, destruction of anterior horns of spine causing paralysis
Amyotrophic lateral sclerosis pathophys
UMN and LMN defects but no cognitive or oculomotor defects. Defective superoxide dismutase 1.
ALS presentation
Fasiculations to atrophy with UMN and LMN signs. No cog defect, Stephen Hawking.
ALS treatment
Riluzole helps some. Decreases presynaptic glutamate release.
Tabes dorsalis
3’ syphilis demyelination of dorsal roots and column. Lose feeling and proprioception. Absence of deep tendon reflexes.
Argyll Robertson pupils
Small bilateral pupils that constrict further to accommodate but not to light. 3• syphilis
B12 or E deficiency on the spine
Degeneration of dorsal columns, lateral corticospinal tracts, spinocerebellar tracts
Poliomyelitis transmission replication and test
Fecal-oral transmission, replicate in oropharynx and small intestine before blood spread to cns. Test for virus in stool or throat.
Werdnig-Hoffman
Congenital anterior horn loss (like polio)
Fredreich ataxia
Frataxin poly GAA repeat causes mitochondrial dysfunction. Causes ataxia.
Hemisection of the spinal cord
Ipsilatetal motor UMN defects(corticospinal) and tactile/vibration/proprioception (dorsal column)
Contralateral pain/temp loss (spinothalamic)
Loss all sensation at the lesion level and side.
Horners syndrome
Sympathectomy of face: ptosis(eye lid droop), anhidrosis(no sweat), miosis (pupil construction)
Dermatome C3
High turtleneck
Dermatome c678
Arms
Dermatome t4
Nipple pore
Dermatome t10
Belly button (butten)
Dermatome L1
Ingunial ligament
Dermatome S
Penis
Dermatome knees
L4
Pineal gland
Melatonin, circadian rhythm, seat of the soul
Superior bs inferior colliculli
Vision , auditory
Cn1
Olfaction. Sensory.
CN2
Optic. Sensory
CN3
Oculomotor
Corneal reflex
V1 to VII
Lacrimation reflex
V1 to VII
Jaw jerk reflex
V3 to v3
Pupillary reflex
2 to 3
Gag reflex
9 to ten
Bicep reflex
C5 root
Tricep reflex
C7 root
Patella reflex
L4 root
Achilles reflex
S1 root
Exit through superior orbital fissure
3, 4, 5.1,6
Exits through foramen rotundum
5.2
Foramen ovale
5.3
Internal auditory meatus
7 8
Jugular foramen
9, 10 , 11
Hypoglossal canal
12
Cavernous sinus syndrome
CN 3,4,5,6 and carotid pass through. Mass effect here disturbs all ocular movement and facial sensation (maxillary, corneal)
Cn 5 motor lesion
Jaw deviates toward injury
CN 10 lesion
Uvula deviates away from lesion
CN 11 lesion
Weakness turning head away and shoulder drop towards
CN12 lesion
Tongue deviates toward
Causes of facial nerve palsy
HAT SLIDe: idiopathic, AIDS, Lyme, HSV, sarcoidosis, tumors, diabetes
Uveitis associations
Systemic inflammatory diseases: sarcoidosis , rheum arth, HLA-b27
Retinitis associations
Viruses: CMV, hsv, hzv. Also immunosuppression
Retinal whitening with cherry red spot
Central retinal artery occlusion
Open glaucoma
Aka wide angle, aqueous humor flows normally past lense. Loss peripheral then central vision. High intraoccular pressure causes damage. Primary is idiopathic, secondary can be uveitis, trauma, steroids, outflow trabecular blockage
Closed glaucoma
Narrow angle. Lense blocks humor flow. Buildup causes high intraoccular pressure.
Chronic asymptomatic
Acute is an emergency, very painful. DO NOT GIVE EPI
Cataracts
Opacification of lens. Corticosteroids, galactosemia, galactokinase deficiency, diabetes (sorbitol), ethanol, smoking.
Papilledema is sxm of
Increased intracranial pressure
Curtains drawn down
Retinal detachment. Surgery indicated.
Types of macular degeneration
Dry: treat with multivitamin and antioxidants
Wet: treat with laser and anti vegf
Down syndrome associated dementia
Alzheimers
Familial Alzheimers proteins/chromosomes
Early onset: APP (21), presenilin-1 (14), presenilin-2 (1)
Late onset: ApoE4 (19)
Protein which protects from alzheimers
ApoE2 (19)
Neurotransmitter disturbance in Alzhiemers
low Acetyl Choline
Alzheimers gross and histo
cortical atrophy, extracellular “senile” plaques of A-beta (from APP) and intracellular neurofibrillary tangles of phospho tau
What in alzheimers correlates with degree of dementia?
neurofibrillary tangles
Frontotemporal dementia
Pick’s disease. Change in personality, aphasia, dementia. Spares parietal lobe, and posterior 2/3 of temporal superior gyrus. Picks bodies of spherical tau protein
Alzheimers complications
intracranial bleed secondary to amyloid angiopathy
Lewy Body dementia
Parkinsonism with dementia and hallucinations. Alpha-synuclein
Creutzfeldt-Jakob Disease
prion spongiopathy which is rapid. “startle myoclonus”
Causes of Mutli-infarct dementia
syphilis, HIV, vitamin B1/2/13 deficency, wilsons, hydrocephalus
Classic Triad of MS
SIN: Scanning speech, Intention tremor (incontenience and internuclear opthalmoplegia), Nystagmus
MS diagnostic features
Increase protein (IgG) in CSF that are oligoclonal. MRI is gold standard. Periventricular plaques. Demylenation with gliosis and axon destruction
MS treatment
Beta-interferon, immunosuppression, natalizumab
infectious agents responsible for guillan-bare
Campylobacter jejuni and CMV (molecular mimicary)
PML
demyelination of cns in AIDS due to JC virus (fatal)
Acute disseminated (post infectious) encephalomyelitis
multifocal perivenular inflammation and demyelination after infxn (measles and VZV) or vaccine (smallpox or rabies)
Metachromic leukodystrophy
recessive lysosomal storage disease due to arylsulfatase A deficiency -> build up of sulfatides which impair myelination
Charcot-Marie-Tooth
onion skin meylination
Krabbes disease
autosomal recessive lysosomal storage disease with defective galactocerebrosidease (break down myelin)
difference between Krabbes and Metachromatc leukodystrophy
Krabbes is defect in galactocerebrosidase
Metachromatic is defect in arylsulfatase A (sulfatides)
simple vs complex partial seizures
both are focal seizures. simple = consciousness intact. complex = consciousness disrupted
status epilepticus
> 30mins seizure. emergency. Children: genetic, infx. Adults: tumors, trauma, stroke, infx.
General seizure types
Abscence/petit mal: just blank out Myoclonic: quick repetitive jerks Tonic-clonic/grand mal: classic seizure Tonic: just stiff Atonic: drop seizure (confused for fainting)
Cluster Headache
> 15mins unilateral headache that is repetitive causes running nose and crying. May cause horners.
Tension Headache
Bilateral >30mins. steady pain and no photophobia/phonophobia or aura.
Migraine
unilateral >4hr with photophobia/phonophobia. aura present. Substance P/CGRP
Vertigo types and differentiation
Peripheral: at the ear (debris, infxn) resulting in delayed horizontal nystagmus. Central: CNS (tumor/stroke at vestibular nuclei), immediate nystagmus at all directions
Sturge-Weber syndrome
Neurocutaneous: port-wine skin stains in the V1 region. ipsilateral leptomeningeal angiomas, pheochromocytomas. Causes: glaucoma, seizures, hemiparesis, and retardation.
Tuberous sclerosis
HAMARTOMAS: Hamartomas in the CNS and skin, Adenoma sebaceum, mitral regurg, ash-leaf spots, cardiac Rhabdomyoma, Tuerous sclerosis, autosomal dOminant, Mental retardation, rengal Angiomyolipoma, Seizures… that was a stretch.
Neurofibromatosis type I
Cafe-au-lait spots, Lisch nodules (pigmented iris hamartomas), cutaneous neurofibromas, optic gliomas, pheochromocytomas. Autosomal dominant with 100% penetrant. NF1 gene on chrom 17
von Hipple-Lindau disease
Cavernous hemangiomas on visceral (skin/mucosa/organs). kidney cancers (bilateral renal cell carcinoma and pheochromocytomas), hemangioblastoma of CNS (retina/brainstem/cerebellum). autosomal dominant. VHL gene on chrom 3
Gliblastoma multiforme
Grade 4 astrocytoma(GFAP). Most common primary brain cancer.
Meningioma
second most common primary brain cancer. from arachnoid cells. benign. psammoma bodies (laminated calcifications)
Schwannoma
3rd most common brain cancer. CN8. S100 positive. Associated with Neurofibromatosis type 2
Oligodendroglioma
rare and slow. chicken wire capillary, fried egg appearance.
Pituitary adenoma
commonly a prolactinoma which presses on the optic chiasm causing bilateral hemianopia.
Pilocytic Astrocytoma
low grade benign, in children, posterior fossa tumor. Rosenthal fibers (eosinophilic corkscrews). Cystic +solid
Medulloblastoma
Highly malignant cerebellar. primitive cells (GCPs). Compresses 4th ventricle -> hydrocephalus. “drop mets” to spinal cord. Homer-wright rosettes. Small blue (high N/C)
Ependymoma
(child)Ependymal cells in the fourth ventricle. hydrocephalus. poor prognosis. perivascular pseudorosettes. Rod-shaped bleopharoplasts (basal ciliary bodies) near nuclei.
Cingulate herniation
under falx cerebri, can compress ACA
uncal herniation
medial temporal lobe herniation through tentorium
Hemangioblastoma
(child)most often cerebellar, VHL syndrome (with rentinal angiomas). EPO increased causing polycythemia. Histo: highly vascular and foamy cells
Craniopharyngioma
Rathke’s pouch childhood tumor confused with pituitary adenoma cause it also compresses optic chiasm. calcified alot to mimic tooth enamel.
Nucleus solitarius
7,9,10 (taste) visceral Sensory info like taste, baro, and gut distention.
Nucleus ambiguus
9, 10. Motor innervation of pharynx, larynx and esophagus
Dorsal motor nucleus
the only sole vagal nuclei, autonomic to heart lungs GI
Who gets subdural hematomas?
Old alcoholic babies