Neuro Flashcards
Alar vs basal plate?
Alar= sensory Basal = motor **BMR= Basal motor rate
What two tests can establish a neural tube defect?
Elevated AFP
Elevated AChE
Anencephaly associations?
Anterior neural fold defect
Elevated AFP
Polyhydramnios
Maternal T1DM
Pt with failure of the 2 cerebral hemispheres to fuse and One centrally located eye has what mutation?
Holoprosencephaly + Cyclopia == Sonic Hedgehog mutation
Arnold-Chiari?
Tonsillar and vermian herniation through foramen magnum
Thoraco-Lumbar myelomeningocele
Paralysis below defect
Child with cystic enlargement of the 4th ventricle, bulging fontanelle, and MRI shows lack of cerebellar vermis?
Dandy-walker = agenesis of cerebellar vermis
Where are Nissl substances located and what are they?
Nissl= RER –> Soma + dendrites
**NOT axon/ hillock
Actions associated with Astrocytes?
BBB Reactive gliosis Removal of excess NTs K+ metabolism Repair
What two types of nerves carry pain and temp?
Free nerve endings –> Everywhere on body
Delta fibers –> Myelinated, Fast, First Pain
C fibers–> Unmyelinated, slow, 2nd pain
What fibers sense fine touch and position?
Meissner’s corpuscles –> Hairless areas
- *Large Myelinated fibers–> Dorsal column
- *Adapt quickly
What fibers sense vibration and pressure?
Pacinian corpuscles –> Deep skin, joints, ligaments
- *Large myelinated
- *Fast adapting
What fibers sense pressure, deep static touch, and position?
Merkels discs –> hair follicles
**Large myelinated,
Adapt SLOWLY
Which fibers adapt slowly and which Fast?
Slow –> Merkel (want to continue to feel static touch)
Fast–> Corpuscles (pressure, vibration we accommodate to)
Layers of a nerve fiber from inside–> out?
Endoneurium -> inflammed in Guillian barre
Perineurium-> permeability barrier, rejoined during microsx
Epineurium->dense CT, contains fascicles + BVs
NE site of synthesis? Inc/dec in what?
Locus ceruleus (pons)
Inc => Anxiety
Dec => Depression
DA site of synthesis? Inc/ dec in what?
Ventral tegmentum + SNc
Inc => Schizophrenia
Dec => PD + depression
5HT site of synthesis? Inc / dec in what?
Raphe nucleus (brain stem) Dec => Anxiety + Depression
ACh site of synthesis? Inc/ dec in what?
Basal nucleus of Meynert (forebrain-> Neocortex)
Inc => REM
Dec => Alzh + Huntingtons
GABA site of synthesis? Inc and dec in what?
Nucleus Accumbens
Dec = Anxiety + Huntingtons
What nucleus is responsible for stress and panic , Reward/pleasure/ addiction?
Stress/panic==> Locus ceruleus
Addiction/reward ==> Accumbens / septal
What forms the BBB?
Tight junctions btwn endothelial cells
Basement membrane
Astrocyte foot processes
What areas do not have a BBB?
Area postrema -> vomiting center
OVLT –> Osmotic center (trigger ADH)
Neurohypophysis-> ADH release
Increased IC pressure due to infections and Neoplasms is due to?
Vasogenic Edema –> Destruction of Endothelial tight junctions
Hypothalmus actions? (TAN HATS)
Thirst Andenohypophysis Neurohypophysis Hunger Autonomics Temperature Sex
What areas give input to Hypothalamus?
OVLT–> Osmotic changes -> ADH release
Area postrema -> Emetics -> ANS activity
Hypothalamic nuclei: actions / def Lateral -> Ventromedial -> Anterior -> Posterior-> Suprachiasmatic-> Supraoptic-> Paraventricular->
Lateral -> Hunger (def = Anorexia) *Inhibited by leptin
Ventromedial=> Satiety (def = Hyperphagia)
anterior=> Cooling (PSNS)
Posterior=> Heating (SNS)
Suprachiasmatic=> Circadian rhythm
Supraoptic -> ADH
Paravenricular=> Oxytocin
If you zap your Lateral hypothalamic nucleus?
You shrink Laterally => controls Hunger
If you zap ventromedial nucleus?
Grow Medially ==> Controls Satiety
Difference btwn Anterior vs Posterior hypothalamic nuclei?
A/C => anterior Cooling (PSNS)
Posterior => heating (SNS)
Thalamic nuclei: VPL VPM LGN MGN Ventrolateral
VPL => Sensory from Body–> postcentral gyrus
VPM-> sensory from FACE -> Postcentral gyrus
LGN -> Eyes (Lateral= Light)
MGN-> Hearing (Music)
VL => Motor
The structures and functions of Limbic system?
Hippo + Amygdala + Fornix + MBs + Cingulate
5 Fs = Feeding, Fleeing, Fighting, Feeling, Fucking
Emotions, Longterm Memory, Olfaction, behavior, ANS
What are the inputs to Cerebellum?
Mossy fibers => Contralateral cortex via Middle peduncle
Climbing fibers=> Ipsilateral proprioception Dorsal columns via Inferior Peduncle
Output from Cerebellum?
Purkinji fibers -> Superior Peduncle-> Contralateral Cortex
Lateral -> voluntary movement of extremities
Medial -> Balance, truncal coordination
Deep nuclei of cerebellum?
Dont Eat Greasy Foods = Lat-> med
Dentate-> Emboliform -> Globose -> Fastigial
What is the cause of the ACh/ GABA neuron loss on Huntingtons?
Excess NMDA-R binding causing GLUTAMATE toxicity
CAG=> Caudate loses ACh and GABA
Action tremor that is exacerbated by holding posture of limb position?
Essential tremor
**Pt self medicate with EtOH
Give Beta Blocker
Hand tremor that is alleviated by intentional movement?
Resting (unintentional) tremor => PD
SLow zigziag pointing or tremor with actions?
Intention tremor–> Cerebellum
Sudden brief uncontrolled muscle contractions?
Myoclonus –> Metabolic encephalopathy
Consequence of losing: Amygdala BL Frontal lobe Right parietal lobe RAS Basal ganglia Subthalamic nucleus Cerebellar vermis Hippocampus Paramedian Pontine reticular formation Frontal eye fields
Amygdala BL => Hyperphagia, hyperoral, hypersexual
Frontal lobe-> Disinhibited, primitive reflexes, judgement
R parietal => Left sided Spatial neglect
RAS -> COMA
BG -> tremor, chorea, PD
Subthalamic=> Contralateral hemibalismus
Cerebellar vermis => Truncal ataxia, dysarthria
Hippocampus => Anterograde amnesia (No new memories)
PPRF => Eyes look AWAY from lesion
FEF => Eyes look TOWARD lesion
Pt with a hx of DM, HTN, and stoke presents with Right sided hemiparesis and hemiplegia. What is the most likely cause?
Lacunar infarct due to HTN @ L INTERNAL CAPSULE
- stroke @ Lateral striate artery => Straitum/ IC can also cause this.
- *
Pt with Left lower limb paresis, loss of proprioception, and dysarthria due to inability to move their tongue to the right. Stroke @ what Artery?
Anterior Spinal Artery **Medial medullary syndrome=> contralateral Lateral corticospinal tract contralateral Medial lemniscus Ipsilateral CN XII
Pt with vertigo, nystagmus, dysphagia, hoarseness, horner’s syndrome, ataxia, decreased Pain + temp to Limbs and face. What artery?
Lateral medullary syndrome => PICA
Vestibular nucleus = Vertigo, nystagmus
Lat spinothalamic tract => dec temp/ pain
**Nucleus ambiguus –> CN IX & X (dysphagia/ hoarseness)
SNS=> horners
Inferior cerebellar peduncle=> Ataxia, dysmetria
Pt with vertigo, nystagmus, decreased pain/temp to face, decreased hearing, meiosis, paralysis of face, dec lacrimation. What artery?
Lateral Pons ==> AICA CN VIII=> vertigo, nystagmus CNVII => facial paralysis Spinal CN V nucleus=> Loss of pain/ temp face SNS=> Horner's Middle/Inferior peduncle => Ataxia
pt with Right sided hemianopia with macular sparing. What artery?
Occipital cortex ==> PCA
Pt with a pure sensory deficit. What is the MCC?
Lacunar infarct of Thalamic nuclei (VPL/VPM)
Charcot-Bouchard aneurysms are MC located in?
Basal ganglia
Thalamus
Pons
Cerebellum
Hypertensive hemorrhage vs Cerebral Amyloid angiography?
HTN ==> Charcot aneurysms of Lenticulostriate vessels==> BG/ IC bleeds
CAA –> LOBAR/ cortex bleeds
During hypoxia and stroke what is the time line for brain damage/ changes?
Damage begins @ 5 min of hypoxia (Hippo / Cerebellum)
12-48 hrs = Red neurons
1-3d -> Liquifactive necrosis + PMNs
3-5d –> Macrophages
1-2wks -> Reactive gliosis + vascular proliferation
>2wks –> SCAR
What tests are done to diagnose stroke?
Diffusion weighted MRI => Early pickup (3-30min)
non-contrast CT –> after 24hrs
Stroke vs TIA?
Stroke = Irreversible focal CNS def, with changes on imaging
TIA -> reversible focal def, < 1 hour, WITHOUT changes on Imaging
Types of stroke:
Atherosclerotic
Hemorrhagic
Ischemic
Atherosclerotic => thrombi->necrosis>Cystic cavity>gliosis
Hemorrhagic-> HTN, Anticoagulants (lower BP)
Ischemic-> PFO, endocarditis, Afib, Carotid dissection, Lacunar strokes (tPA <4.5 hrs)
Normal pressure hydrocephalus vs. Hydrocephalus ex-Vacuo?
Normal pressure=> Expansion of ventricles distort Corona radiate -> Wet, Wacky, Wobbly
Hydrocephalus ex-vacuo=> Inc CSF due to cerebral ATROPHY (Alzh, HIV, Picks), NO triad
**BOTH have Normal IC pressure
Pseudotumor cerebri?
Benign IC HTN >300 Obese woman + headache + blurry vison NORMAL labs + Neuro exam Dec CSF absorption Rx: Carbonic Anhydrase inh
Two causes of LMN lesions ONLY?
Poliomyelitis
Werdnig-Hoffman disease
Pt with both LMN / UMN and no ANS defects. What is the mutation and Rx?
ALS –> SOD 1 mutation
**Riluzole –> dec presynaptic Glutamate release which is know to be toxic at high levels due to excess Ca+
Pt with abdominal surgery to repair AAA begins to complain of weakness and loss of sensation. What is the cause and what is spared?
Loss of Artery of Adamkiewicz –> ASA
**Spares Dorsal columns & Lissauer’s tract (medial portion of spinothalamic tract)
Pt with +Romberg and absence of DTRs complains of joint pain and blurry vision. Most likely cause?
Tertiary syphilis –> Tabes dorsalis
Argyll Robertson pupil-> Accommodates but Doesnt React
What is affected in B12 def?
Subacute combined degeneration
Dorsal columns
Lateral corticospinal tracts
Spinocerebellar tracts
Infant baby is “Floppy,” has marked hypotonia, and tongue fasciculations. What is the dx and seen on biopsy of Spinal cord?
Werdnig hoffman –> Degeneration of Anterior horn
young boy presents with ataxia, nystagmus, pes cavus, hammer toes, and kyphoscoliosis. Echocardiogram reveals enlarged heart. What it the molecular cause of his disease?
Friedreich’s ataxia–> GAA repeats
- *Impaired MITOCHONDRIAL function
- *Ataxia + Hypertrophic cardiomyopathy
Conjugate vertical gaze center?
Superior colliculus
**Below Pineal gland –> Cancer gaze vertical gaze palsy due to compression == Perinaud syndrome
Cranial nerve nuclei locations:
Midbrain
Pons
Medulla
Midbrain= CN 3 + 4 Pons = CN 5 + 6 + 7 + 8 Medulla = CN 9 + 10 + 12
Vagal nuclei functions:
Solitarius
Ambiguus
Dorsal motor nucleus
Solitarius –> Visceral Sensory from VII, IX, X (Taste, baroreceptors, gut distention)
aMbiguus => Motor IX, X
Dorsal => PSNS via X
Pt with hearing difficulties has an abnormal Rinne test, and Weber test localizes to the left ear. What is the cause?
Conductive hearing loss in LEFT ear
**Weber localizes in Affected ear
Pt with hearing difficulties has a normal Rinne test and Weber localizes to the Left ear?
Sensorineural hearing loss in the RIGHT ear
**Weber localizes in Unaffected ear
Pt with noised induce hearing loss has damaged what? Sudden extremely loud noise can damage?
Noise induced=> Damaged to Stereocilliated cells in Organ of Corti-> Loss of High freq 1st
Sudden loud noise–> Tympanic membrane rupture
LMN vs UMN lesion to facial muscles?
UMN -> Contralateral Lower face paralysis only (BL UMN innervation of Forehead)
LMN –> Ipsilateral Total facial paralysis
Elderly man with decreased ability to focus during accommodation. What it the most likely cause?
Sclerosis and decreased Elasticity ==> AGING
Pt with a history of back pain comes with blurry vision and pain. Eye exam shows uveitis. What parts are affected by inflammation and Rx?
HLA-B27 association
**Inflammation of Uveal coat (iris, ciliary body, choroid)
Rx: STEROIDS
Retinitis associations?
Retinal edema and Necrosis
Immunosuppressed == CMV, HSV, HZV
Pt comes in with acute loss of vision in one eye. Eye exam shows “whitening with cherry-red spots” and no pain is noted during exam. Dx?
Central Retinal artery occlusion –> Temporal arteritis
**CRVO => ischemia and edema Rx: Anti-VEGF
What produces aqueous humor of the eye and what receptors stimulate them? Dilator & sphincter receptors?
Ciliary epithelium
- *Beta 2 receptors
- *Dilator = alpha 1
- *Sphincter = M3
Pt suffers from gradual painless loss of peripheral vision. What can causes this?
Open (wide) Angle Glaucoma = Inc IOP + CN 2 Atrophy
- Dec Outflow through trabecular meshwork
- Hx of uveitis, trauma, Steroids, vasoproliferative retinopathy
What is the cause of Closed angled glaucoma?
Forward movement of the Lens against central iris to block aqueous flow through PUPIL
Acute vs Chronic closed angled glaucoma?
Chronic=> Asymptomatic, Inc IOP, CN2 atrophy
Acute= Emergency, Inc IOP, VERY painful, sudden loss of vision, Halos around lights, frontal headache, Epi Is CI
Rx: Pilocarpin or CA inhibitor
Pt with sudden onset of Painful vision loss, headache, and halos around lights?
Acute closed angled glaucoma
What are risk factors for Painless bilateral opacifications of the lens?
Cataracts: EtOH **Diabetes Classic Galactosemia + Galactokinase def **Corticosteroids
PSNS vs SNS tracts to Eyes?
PSNS=> Edinger-Wesphal->CN3-> Short ciliary n
SNS->Hypothalamus->C8-T2->Sup Cerv Gang->ICA->Long ciliary nerve
Pt presents with flashes and floaters in the left eye. Hrs later complains of acute vision loss as if “curtains were drawn down” on eyes?
Retinal Detachment
Pt comes in with continuous distortion of vision and now complains of central vision loss?
Macular degeneration
Dry vs Wet Macular degeneration?
Dry (80%)-> “drusen” (proteins) deposits beneath retinal pigment epithelium (prevent with Multivitamin/Antioxidant)
Wet-> Rapid loss of vision due to Choroidal neovascularization (Anti-VEGF)
Visual defect locations: Homonymous hemianopia Upper quadrantic anopia Lower quadranic anopia Hemianopia with macular sparing Central scotoma
Homonymous hemianopia= TRACT Upper => Meyers Loop Lower => Radiations Hemianopia Macular sparing=> PCA/ Visual cortex infarct Central scotoma=> MD/ Lens defect
Highly myelinated tract in the eye that is often first to go in MS?
MLF –> NOT involved in convergence
MCCs of ophthalmia neonatorum? Rx?
- Chlamydia trachamatis => Erythromycin
2. N gonorrhea => Ceftriaxone
MCC of viral conjunctivitis?
Adenovirus –> pink eye
HSV1 –> Keratoconjunctivitis + dendritic ulcers
Young patient with Loss of vision and Pain on eye movement. What are MCCs of this dz?
Optic Neuritis –> Rx with Steroids
- MS
- Methanol
AIDs pt with “cotton wool exudates” and retinal hemorrhage on eye exam?
CMV retinitis –> MCC of blindness in AIDs pts
MCC of “swimmers ear” and Malignant external otitis in DM?
Both P. aeruginosa
- swimmers –> Rx Polymyxin B
- Malignant-> Impenem-Cilastin
Pt complains of vertigo, dizziness, and sensorineural hearing loss. What is the mechanism of her disease?
Meniere’s dz–> Inc Endolymph in inner ear
Rx: HCTZ + Triamtrene
MCC of sensorineural hearing loss in the elderly is due to?
Presbycusis–> Degeneration of hairs in the Base of Organ of Corti
Rx: Cochlear implants
What is the MCC of conductive hearing loss in the elderly?
Osteosclerosis –> Fusion of middle ear ossicles
MCC of otitis media in kids?
S pneumo > H flu > Morexella
Classical characteristic presentations of MS?
20-30s female
Inflammatory + demyelination of Brain& spinal cord
Optic neuritis + INO + hemiparesis/hemisensory loss
Bladder/ Bowel incontinence
Relapsing remitting
SIN (scanning speech, Intention tremor, INO, Incontinence, Nystagmus)
Lab findings associated with MS? Rx?
CSF=> Inc IgG, Oligoclonal bands
MRI (goldstandard) -> “Periventricular plaques”
(Oligodendrocyte loss + Axonal destruction)
What is the treatment of MS? spasticity associated with it?
Beta interferon –> Immunosuppression
Baclofen –> GABA agonist for SPASTICITY
Characteristics of Guillian barre?
Destroy Schwann cells –> Inflammation/ demyelination
Inc CSF proteins + Normal cell count –> aka “albuminocytologic dissociation”
Campylobacter + CMV Molecular mimicry
Rx: IV immunoglobulins + PLASMAPHERESIS
What is adrenoleukodystrophy?
XR def in enzyme for VLCFA oxidation in PEROXISOMES
Accumulation of VLCFA
Adrenal insuff + demyelination
Rapidly progressive demyelination/ destruction of Oligodendrocytes in AIDs pt is caused by?
Reactivation of JC –> PML
Lysosomal storage disease associated with build up of Sulfatides which impair production of myeline sheaths?
Metachromatic leukodystrophy –> Arylsulfatase A def
Hereditary motor and sensory neuropathy related to defective production of Proteins involved in the function of Peripheral nerves or Myelin sheaths. Often have Orthopedic abnormalities?
Charcot-Mary tooth –> ARCHED feet + hamar toes
**PMPzz del **
Partial seizures are?
Simple partial vs Complex partial?
Partial = affects 1 area, MC originate in Temporal lobe, preceded by seizure aura Partial = Consciousness intact Complex= Impaired consciousness
Recurrent seizure disorder not counting Febrile seizures?
Epilepsy
Status epilepticus is defined by?
Continuous seizure > 30 min OR
recurrent seizures without regaining consciousness btwn seizures for >30min
Causes: genetic, tumor, strokes, trauma, infections
Characterized by 3Hz on EEG, no postictal confusion, and blank stare?
Absence = Petit mal seizures
Seizures characterized by quick repetitive jerks with Normal consciousness?
Myoclonic
Seizures characterized by Alternating stiffening and movement, postictal confusion, tiredness?
Tonic clonic –> grand mal
**Nocturnal form = Lennox Gustaut
Tonic vs atonic seizures?
Tonic –> Stiffening
atonic–> Drop or loss of muscle tone (confused for fainting)
What is thought to be the cause of Migraines? Rx and prophylactic?
Irritation of CN V, meninges, blood vessels via Excess release of substance P + CGRP = vasoactive peptides
Rx Triptans
Prophylactic= Propranolol + Topiramate
What are the characteristics of BPPV?
Positional/ morning / laying back
Otoliths trapped in Posterior semicircular canal
Dx: Dix halpike maneuver
Rx: Epley maneuver
Pt with broun stains around his mouth, benign vascular growths in CNS, elevated BP, seizures, and mental retardation?
Sturge-Weber syndrome: Port-wine stains V1 distribution Leptomeningeal angiomas Pheochromocytoma Seizures, glaucoma, retardation
Tuberous sclerosis associations?
HAMARTOMAS Adenoma sebaceum (cutaneous angiofibromas) "Mitral regurg" Ash-leaf spots Rhabdomyomas autosomal Dominant Mental retardation renal Angiomyolipomas Seizures
NF1 associations?
Lisch nodules (Pigmented iris hamartomas) Optic gliomas
Cavernous hemangiomas, BL renal cell carcinoma, Hemangiobalstoma?
VHL
Gliobastoma multiforme associations?
MC overall primary
+ Necrosis + hemorrhage
Meningioma associations?
Benign arising from “Arachnoid cells”
Dural tail of CT
Seizures + focal signs to compression
“spindle cells” + WHORLED + Psammomas
What CNS tumor is S-100 positive?
S-100= Ca binding protein (Calmodulin like)
Schwannomas
Melanomas
Slow growing CNS tumor with “fried egg” appearing cells and prominent delicate vasculature?
Oligodendrogliomas
Benign Cerebellar tumor that is cystic and solid. What is seen on biopsy?
Pilocytic astrocytoma –> Rosenthal fibers (intermediate fibers)
Medulloblastoma associations?
Malignant cerebellar tumor Hydrocephalus by compressing 4th ventricle "Drop mets" to spinal cord Homer-wright rossets + Small blue cells Radiosensitive due to high malignancy
Tumor characterized by “perivascular pseudorossets?”
Ependymoma
Pt with cerebellar tumor that is highly vascularized and has “Foamy cells.” Labs reveal polycythemia?
Hemangioblastoma ==> VHL association
Herniations and their associations: Cingulate (subfalcine) Transtentorial (Central) Uncal Cerebellar tonsillar
Subfalcine–> Compress ACA
Central –> Compress brainstem + Duret’ hem in pons, Cheyne stokes resp
Uncal –> CN3
Tonsillar–> Coma/death compress Resp center @ BS
