Neuro-First Aid

Medical Sciences Medical School Block Ix Neuro with Wagner at University of Texas - Southwestern Medical Center at Dallas

About this deck

By: Pamela Hoof
Created: 2012-05-29
Size: 102 flashcards
Views: 15

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Where in the neuron is Nissl substance located? Where is it not located?

Nissl substance (RERs) located in the cell body and dendrites

Not the axon

Oligodendroglia/ oligodendrocytes

-myelin-producing glial cells of CNS

-one oliodendroglial cell myelinates multiple axons in the CNS

-destroyed in multiple sclerosis

Schwann cells

-produce myelin in the PNS

-Destroyed in Guillain-Barre syndrome

-Acoustic neuroma assoc. with NF2 is a type is Schwannoma

typically located in the internal acoustic meatus

Free nerve endings

Skin receptors that detect pain and temperature

Type Aδ fast, myelinated and Type C slow,unmyelinated

- located in glabrous (hairless skin, e.g. lips fingers); -have highest sensitivity (lowest threshold) when sensing vibrations lower than 50 Hz;

- type of mechanoreceotor; rapidly adapting fibers for position sense, dynamic fine touch (manipulation) signal that something is touching the skin
small receptive fields

-non-localized nerve endings in the skin

-Located in the deep skin layers,ligaments and joints

-responsible for sensitivity to vibration and pressure. Vibrational role may be used to detect surface, e.g., rough vs. smooth.
-fast adapting, large field
-100-300 Hz

What kind of fibers are in Merkel's disks?

Large, myelinated fibers

Found in hair follicles

Position sense, static touch (shape, edges, texture) - adapts slowly

Peripheral Nerve Layers (out to in)

Epineurium-dense connective tissue that surrounds the entire nerve
Perineurium:surrounds a fascicle of nerves; must be rejoined for limb attachment
Endoneurium-surrounds single nerve fibers, affected by Guillian-Barre

Where is NE synthesized? How does the level of NE change in anxiety? in depression?

Locus ceruleus & reticular formation, solitary tract.

Increase in anxiety

Decrease in depression

Where is dopamine synthesized? How are its levels affected in schizophrenia, Parkinsons?

Ventral tegmentum and Substantia nigra pars compacta

↑ Schizophrenia

↓ Parkinsons

Where is 5-HT synthesized and what diseases are associated with changes in levels?

Raphe nucleus

Decrease in anxiety, depression (ALERTNESS)

*serotonergic predominance in Raphe nucleus important in initiating sleep*

Where is Ach synthesized? Associated diseases?

Basal nucleus of Meynert.

Decreased in Alzheimer's, Huntington's.

and REM sleep.

Where is GABA synthesized? How are its levels affected in anxiety and Huntington's?

Nucleus accumbens

↓ in both

Reticular Activating System (RAS)

Group of neurons in the brain stem that plays a key role in arousal.

-Reticular formation

-Locus ceruleus

-Raphe nucleus

Hypothalmus Functions

TAN HATS
Thirst
Adenihypophysis
Neurohypophysis
Hunger
Autonomics
Temperature
Sexual Arousal

Lateral area of hypothalmus

-feelings of hunger

-Inhibited by leptin

-Destruction leads to anorexia

ventromedial hypothalmus

-feelings of satiety

-Stimulated by leptin

-Destruction leads to hyperphagia

Most common is craniophaygioma

Anterior Hypothalmus

Cooling

Parasympathetics

Posterior Hypothalmus

Heating

Sympathetics

Suprachiasmatic nucleus

Circadian rhythms

Limbic System

5 Fs- feeding, fleeing, fighting, feeling, sex
Include cingulate gyrus, hippocampus, fornix, mammillary bodies, and septal nucleus

Cerebellum -- DONT EAT GREASY FOODS

receives CONTRAlateral cortical input via middle cerebellar peduncle and IPSIlateral sensory proprioceptive input via inferior cerebellar peduncle >> input nerves = climbing and mossy fibers

Provides stimulatory feedback to contralateral cortex to modulate movement; output nerves = Purkinje fibers to deep nuclei of cerebellum >> output to cortex via superior cerebellar peduncle Deep nuclei LtoM??

L >> M

Dentate, Emboliform, Globose, Fastigial

Lateral = voltunary movement of extremeities

Medial = balance, truncal coordination, ataxia; when injured, propensity to fall toward injured (ipsilateral) side

Hemiballismus

Sudden, wild flailing of 1 arm +- leg
Characteristic of contralateral subthalamic nucleus lesion

Leads to loss of inhibition of the thalmus through the globus pallidus externa

Huntington's disease

-CAG repeat→Caudate loses ACh and GABA

-Chorea,Agression,depressions, dementia

-Atrophy of striatal nuclei= loss of main inhibitors of movement

Kluver-Bucy Syndrome

Bilateral amygdala lesion (ablation)
Flattened emotions
Non-aggressive behavior
Visual agnosia
Hyperorality/sexuality
Assoc. with HSV-1

Frontal lobe lesion leads to what symptoms?

-Disinhibition

-defects in concentration, judgement, and orientation

-Return of primitive reflexes

Spatial neglect syndrome - agnosia of the contralateral side of the world

Right parietal lobe

Tremor at rest, chorea, or athetosis

Basal ganglia lesions

Truncal ataxia and dysarthria are assoc. with ??

Cerebellar vermis lesions
vermis is centrally located and affects the central body

Lesions of the subthalamic nucleus leads to...

Hemiballismus

Lesions of the hippocampus lead to?

Anterograde amnesia- inability to make new memories

Lesion of Paramedian pontine reticular formation leads to......

eyes look away from side of lesion

Lesion of frontal eye fields leads to....

eyes look toward lesion

acute paralysis, dysarthria, dysphagia, diplopia, and loss of consciousness

very rapid correction of hyponatremia

Aphasia vs dysarthria

Aphasia - higher order inability to speak

dysarthria - motor inability to speak

What are the symptoms of an MCA stroke?

Contralateral paralysis of upper limb & face
Contralateral loss of sensation of upper limb & face
Hemineglect if lesion affects nondominant (usually right) side
Aphasia if dominant side

What are the symptoms of a stroke of the ACA?

Contralateral paralysis of lower limb
Contralateral loss of sensation of lower limb

Symptoms of stroke in lateral striate arteries?

-Contralateral hemiparesis/hemiplegia

-WHy? Bc the lateral striates perfuse the neostriatum and internal capsule

-Common location of lacunar infarcts due to chronic hypertension

Stroke of Anterior SPinal Artery leads to what symptoms?

-ASA covers lateral corticospinal tract, medial leminiscus, hypoglossal nerve

Contralateral hemiparesis of lower limbs
↓ contralateral proprioception
Ipsilateral hypoglossal dysfunction-tongue deviates ipsilaterally

What are the effects of a stroke of the PICA?

Lateral medullary syndrome

Vomitting,Vertigo, nystagmus
↓Pain/temp sensation in limbs and face
Ipsilateral Horner's
Ataxia

Nucleus ambiguus effects (hoarsness, dysphagia) - specific to PICA lesions

Don't pick a (PICA) horse that can't eat

What are the effects of an AICA stroke?

Lateral Pontine Syndrome: Vomiting, vertigo, nystagmus (vestibular nuclei)

Ipsilateral: ataxia (MCP); ↓ facial pain & temp (trigeminal nucleus); facial paralylsis, ↓ lacrimation & salivation, ↓ taste from ant. 2/3 of tongue, ↓ corneal reflex (facial nucleus); ↓ hearing (cochlear nuclei), Horner's syndrome

* Facial nuc. effects specific to AICA lesions - facial droop means AICA's pooped.

What are the symptoms of a PCA stroke?

Contralateral hemianopsia with macular sparing, thalamic injury, Weber's syndrome: contralateral weakness and CNIII paresis/pupil dilation.

Berry Aneurysm assw what renal problem

Most common site is brach point of ACA
-Assoc with:

ADPKD
Ehlers-Danlos
Marfan's
Charcot-Bouchard:microaneurysms associated with

Epidural Hematoma

Rupture of middle meningeal artery, secondary to fracture of temporal bone
Lucid Interval
RAPID progression-due to increased intracranial pressure leading to transtentorial herniation
Shows as CN III palsy
"Lens shaped" DOES NOT CROSS SUTURE LINES, can cross falx/tentorum

SUBEPIDURAL HEMATOMA

-Rupture of bridging veins

Slow bleed due to less pressure

-Elderly, alcoholics, shaken-baby syndrome

-Crescent shaped hemorrhage that crosses suture lines with MIDLINE SHIFT;preserved gyri

-Cannot cross falx.tentorium

What are the characteristics of normal pressure hydrocephalus?

Expansion of ventricles distorts fibers of corona radiata → clinical triad:"Wet, Wobbly, Wacky"

Does not result in ↑ subarachnoid space volume.

Intraparenchymal hematoma

Commonly assoc with systemic hypertension
Basal ganglia and internal capsule

What are the characteristics of normal pressure hydrocephalus?

Expansion of ventricles distorts fibers of corona radiata → clinical triad: Wet, wobbly, wacky

Dementia, Ataxia, and urinary incontinence
Reversible cause of dementia in the elderly

Does not result in ↑ subarachnoid space volume.

What are the characteristics of communicating hydrocephalus?

↓ CSF absorption by arachnoid villi (e.g. arachnoid scarring post-meningitis), leads to ↑ pressure, papilledema, herniation

What is obstructive/non-communicating hydrocephalus?

Occurs when there is structural blockage in the outflow of CSF. Common causes are congenital stenosis of the cerebral aqueduct of Sylvius and the Arnold-Chiari malformation.

What is hydrocephalus ex vacuo?

Appearance of ↑ CSF in atrophy, e.g. Alzheimer's disease, advanced HIV, Pick's disease.

Intracranial pressure is normal, triad not seen.

Most common site of vertebral disk herniation?

Nucleus pulposus herniates through Annulus fibrosis) between L5/S1

Adult Spinal cords end at

L1/L2

the subarachnoid space ends where

the lower border of S2 where the dura attaches to the film terminal. The filum terminal descends to attach to the coccyx.

Where is the lumbar puncture done?

B/t L3-5 level

Ascending pathway for vibration and propiroception
1st order neuron: sensory nerve ending→cell body in dorsal root ganglion→enters spinal cord and ascends IPSILATERALLY in dorsal column
Synapse 1=IPSILATERAL nucleus cuneatus or gracilis
Decussates at medulla and ascends in CONTRALATERALLY in medial lemniscus
Synapse 2 is VPL of thalmus.... then sensory cortex

Sensory pathway originating in the spinal cord. It transmits information to the thalamus about pain, temperature, itch and crude touch. The pathway decussates at the level of the spinal cord; Two divisions:

The lateral spinothalamic tract transmits pain and temperature.
The anterior spinothalamic tract (or ventral spinothalamic tract) transmits crude touch.

Spinothalamic Tract Pathway

Ascending: Pain and Temp

Neuron 1: A-delta, C-fibers to DRG(body), enters SC in Lissauer t.

Synapse 1: IPSILATERAL gray matter on dorsal horn

Neuron 2: Decussate across Ant. White commissure and ascends CONTRALATERALLY

Synapse 2: VPL - Thalamus

Neuron 3: Thalamus to 1' Sensory Cortex

Lateral Corticospinal tract Pathway

Descending: Voluntary contralateral limb movement

Neuron 1: UMN: cell body in 1' motor cortex, descend ipsi through Internal capsule to pyramidal decussation in medulla, descend contralaterally

Synapse 1: on ventral horn cell bodies in spinal cord (via interneuron)

Neuron 2: LMN: exits the Spinal cord from ventral horn

Synapse 2: NMJ!

Poliomyelitis

Poliovirus transmitted via fecal-oral
Destruction of cells in the anterior horn of the spinal cord=LMN destruction
Sore throat, weakness/atrophy,fasciculations and hyporeflexia
Key finding = CSF with lymphcytic pleocytosis with slight elevation of protein;normal glucose
Virus recovered from stool or throat

Werdnig-Hoffman disease

-infantile spinal muscular atrophy

-AR,presents at birth

-Due to degeneration of anterior horn

floppy baby, tongue fasciculations

Amyotrophic lateral sclerosis

ALS=Anterior Horn+Lateral Spinothalamic+Superoxide dismutase def.
both UMN and LMN signs

Tabes dorsalis

3° syphilis leading to destruction of dorsal columns and dorsal roots
Assoc. with Chacot joints, shooting pain, Argyll Robertson pupils, absence of Deep tendon reflexes, and positive Romberg sign
Sensory ataxia at night

Friedrich's ataxia

GAA triplicate repeat in frataxin gene
Impaired mitochondrial functioning
Staggering gait, falling, nystagmus, hypertrophic cardiomyopathy

Hemisection of the spinal cord:

At the level of lesion: LMN signs and ipsilateral loss of all sensation

Below the lesion:

Ipsilateral spastic paralysis (UMN signs)

Contralateral pain and temperature loss

Ipsilateral loss of touch, vibration, proprioception

** If lesion is above T1=Horner's syndrome

What is the 3-neuron oculosympathetic pathway?

1st neuron in hypothalamus → synapse in lateral horn → 2nd neuron thru sympathetic chain, synapsing in Sup. cervical ganglion → 3rd neuron to SM of eyelids, dilator pupilae m., sweat glands of forehead and face

This pathway is disturbed in Horner's syndrome

Any lesion of the spinal cord above T1 causes what?

Horner's syndrome

Ptosis
Anhidrosis
Miosis

Parinaud syndrome

-Paralysis of conjugate vertical gaze due to lesion of superior colliculi

2 nerves responsible for taste and lacrimation

1. Facial Nerve= taste in anterior 2/3 of tongue and salivation of submandibular and sublingual glands

2. Glossopharyngeal N. =taste in posterior 1/3 of tongue and salivation from parotid gland

nucleus of the tractus solitarius (NTS)

-Vagal nuclei that receives sensory info about taste, gut distention, and baroreceptors

-VII,IX,X

Nucleus AMbiguus

nuclei for Motor innervation of pharynx,larynx, and upper esophagus

-Swallowing, palate elevation

IX, X, XI

What is the function of the dorsal motor nucleus?

CN X - sends autonomic (parasympathetic) fibers to heart, lungs, and upper GI

what exits out of the superior orbital fissure?

CN III, IV, VI, V1,

opthalmic vein and sympathetic fibers

Internal
Internal Carotid Artery

Abducens Nerve

External

Ocularmotor Nerve (III)

Trochlear Nerve (IV)

Opthalmic Nerve (V1)

Maxillary Nerve (V2)

Blood drains from eye and superficial cortex→cavernous sinus→internal jugular vein

What are the symptoms of cavernous sinus syndrome?

ophthalmoplegia, ophthalmic and maxillary sensory loss

-due to mass effect

-Remember that that all nerves controlling extraocular movement pass through the cavernous sinus

Causes of Bell's Palsy

My Lovely Bella Had an STD - Lyme Disease, Herpes, AIDS, Sarcoidosis, Tumors, Diabetes

What is the consequence of retinal artery occlusion? What are the findings?

Acute, painless monocular loss of vision.

Pale retina and cherry-red macula (macula has own blood supply - choroid artery)

What's the main pathway of aqueous humor?

Through the trabecular meshwork through to the canal of Schlemm

What causes open/wide angle glaucoma? What is it associated with?

Gradual obstruction of outflow (e.g. canal of Schlemm). Angle between iris and cornea is wide/open which is normal.

Associated with myopia, ↑ age, African-American race

More common, "silent," painless, develops slowly.

Closed angle glaucoma

Acute onset. The opening between the cornea and iris narrows so that fluid cannot reach the trabecular meshwork. This can cause a sudden increase in the intraocular pressure that produces pain, nausea, redness of the eye, and blurred vision.

-Rock hard eye and frontal headache

-EMERGENCY

-Do not give epinephrine

Functions of III Oculomotor Nerve other than specific musle control

Accomodation
Pupillary constriction
eye opening-levator palprebrae
SR, IR, MR, IO

the involved eye does not react to light directly (the other eye also does not show anything indirectly) - afferent response
but does constrict to light directed to the opposite eye (consensual response) - efferent response

Age-related macular degeneration (AMD)

-Retinal detachment and degeneration of photoreceptors in the macula
- loss of visual acuity in the center of the visual field
- leading cause of blindness in people over 60

-Dry=slow, due to fat deposits an causes gadual vision loss

-Wet= new vascularization,rapid loss of vision

Familial form of Alzheimers is assoc. with what genes??

Early onset: APP (21), presenilin-1 (14), presenilin-2 (1)

Late onset: ApoE4 (19)

*** Apo E2 on 19 is protective

Lewy Body dementia vs. Pick disease

Lewy Body Dementia: α-synuclein defect; key is hallucinations

Pick Disease: tau protein in Pick bodies, frontotemporal dementia w/ personality changes

Charcot's Triad for MS

SIN

- Scanning speech

Intention tremor / incontinence /internuclear opthalmoplegia

Nystagmus

What are symptoms of Charcot-Marie-Tooth disease?

distal muscle wasting, pes cavus (high foot arches), claw hand (abduction of thumb, flexion at the PIP joint, extension at the MCP joint), hypertrophy of greater auricular nerve, foot drop

-defective production of neural proteins

Acute diseminated postinfectious encephalopathy

multifocal periventricular inflammation and demyelination postinfection

STURGE-WEBER SYNDROME - rare congenital neurocutaneous disorder often associated with port-wine stains (PWS) on face, glaucoma, mental retardation, ipsilateral leptomeningeal angiomas (V1 & V2 distribution), pheochromocytoma

Clinically: Seizures (LA), Focal Neurologic Deficits, Developmental Delay

Treatment: Anticonvulsants, NSAIDS for H/As, Glaucoma treatment, Aspirin, Laser for PWS

Neurofibromatosis type 2 displays what symptoms? Which chromosome is it on? How is it inherited?

bilateral acoustic schwannomas; juvenile cataracts; chromosome 22 (neurofibromatosis type 2) AD

tuberous sclerosis

HAMARTOMAS mnemonic for tuberous sclerosis:

Hamartomas, adenoma sebaceum, mitral regurgitation, ash-leafspos, cardiac Rhabdomyoma, (tuberous sclerosis0, autOsOmal dOminant, Mental retardation, renal Angiomyolipoma, Seizures

Etiology: mutation of the NF1 gene on the long arm of chr 17 (17 letters in "von Recklinghausen"); autosomal dominant

Findings:

-Cafe au lait spots

-Neural tumors

-Lisch nodules (pigmented iris -hamartomas)

-Skeletal disorders: Scoliosis

-Optic pathway gliomas

Von Hippel-Lindau

inherited multi-system disorder
abnormal growth of blood vessels (as knots)
mut. VHL on chromosome 3 (3p) mutation

Hemangioblastoma
Cavernous hemangioma (brain, retina)
Adenomas/cysts (liver, kidney, pancreas, others)

Associated w/ bilateral clear cell renal cell carcinoma

CT of butterfly appearance bc it can cross corpus callosum, with central necrosis is classic for GBM

most common primary brain tumor

stain w/ GFAP; PSEUDOPALISADING pleiomorphic cells

Headaches, seizures, focal deficits

Requires surgical resection

Meningioma

2nd most common brain tumor in adults. Parasaggital. From arachnoid cells. Resectable. Spindle cells in whorl. psammomma bodies.

S-100 stains for?

Schwannoma

oligodendroglioma histology

rare,slow growing in frontal lobes

calcifications

fried egg pattern with chicken-wire capillary pattern

most often in children in the posterior fossa; well circumscribed; GFAP+, good prognosis

Rosenthal fibers (eosinophilic corkscrew fibers)

Benign, good prognosis

medulloblastoma

small round blue cells with Homer-Wright rosettes
PNET tumor
Can compress 4th ventricle causing hydrocephalus

4th ventricle, hydrocephalus, children

Perivascular pseudorosettes

Poor prognosis

hemangioblastoma histology, associations

foamy cells, high vascularity

assoc. with VHL syndrome

can produce EPO → 2° polycythemia

craniopharyngioma

calcified, cystic tumors

arise from Rathke's pouch

cause headache, growth failure, bitemporal hemianopia

About this deck

By: Pamela Hoof
Created: 2012-05-29
Size: 102 flashcards
Views: 15

About StudyBlue

“Simply amazing. The flash cards are smooth, there are many different types of studying tools, and there is a great search engine. I praise you on the awesomeness.”
Dennis