Neurology 2

bananas's version from 2015-05-26 15:39

Bleeding of brain

Question Answer
Epidural hematomaRupture of middle meningeal artery (branch of maxially artery) - 2° to fracture of temporal bone
Lucid then transtential herniation, CN III palsy
CT: biconvex (lentiform), hyperdense blood not crossing suture lines, but can cross falx, tentorium
Subdural hematomaRupture of bridging veins
Slow venous bleeding - elderly, alcoholics, blunt trauma, shaken baby
Crescent-shaped hemorrhage that crosses suture lines
Midline shift
Cannot cross falx, tentorium
SA hemorrhagerupture of aneurysm (ie berry) or an AVM
worst HA of life + CN3 palsy
Bloody/yellow spinal tap
risk of vasospasm 2-3 days later due to breakdown of blood products-->irritated vessels so treat w/Ca channel blockers (nimodipine)
Parenchymal hematomacaused by HTN
also w amyloid, vasculitis, and neoplasm (diabetes also)
lobar strokes all over brain - usually in BG and internal capsule (lenticulostriate vessels)
Most vulnerable areas of brain to ischemic damage?hippocampus, neocortex, cerebellum, watershed areas
Histology of brain damage after ischemia?Irreversible after 5 minutes of hypoxia
red neurons (12-48 hrs)
necrosis + neutros (24-72 hrs)
macros (3-5 days)
reactive gliosis + vascular proliferation (1-2 wks)
glial scar (>2 wks)
Stroke imagingbright on diffusion-weighted MRI in 3-30 min and remains bright for 10 days, dark on CT in 24 hrs
Venous sinusesrun in dura mater where meningeal/periosteal layers separate, cerebral veins-->sinuses-->IJV
Bright areas on noncontrast CThemorrhage (tPA is contraindicated)
Cystic cavity with reactive gliosisAtherosclerosis - thrombi lead to ischemic stroke w subsequent necrosis
Type of necrosis seen with brain infarctionliquifactive


Question Answer
Ventricle pathwaylateral-->3rd via foramen of monro--> cerebral aqueduct-->4th-->SA space via Luschka (lateral) and Magendie (medial)
Normal pressure hydrocephaluswacky/wobbly/wet
NO increase in SA space volume, expansion of ventricles disrupts fibers of corona radiata → dementia, ataxia, urinary incontinence
Communicating hydrocephalusless CSF absorption by arachnoid granulations → increased icp → papilledema and herniation
Hydrocephalus ex vacuoincreased CSF in atrophy (Alzheimers, advanced HIV, picks), ICP is normal and triad not seen
Noncommunicating hydrocephalusStructural blockage (stenosis of aqueduct of sylvius)

Spinal nerves and tracts

Question Answer
What info is carried by Dorsal Column? (DC-ML)Ascending
Pressure, Vibration, Fine touch, Proprioception
What info is carried in the Lateral Corticospinal tract?Descending voluntary movement of contralateral limbs
Lateral spinothalamic tractPain + Temperature
Anterior spinothalamic tractCrude touch + pressure
What info is carried in the Trigeminal?Pain and temperature from the Face
Orientation of lateral coricospinal tractlegs are lateral
Orientation of dorsal columnsArms are lateral (fasciculus cuneatus)
Legs are medial (fasciculus gracilis)
UMN lesionUp Up Up! Increased tone and reflexes
- Spastic paralysis
LMN lesionDowwwwwn: Decreased muscle mass, Tone and Reflexes
- Flaccid Paralysis
- Fasciculations
Aδ & C fibersPain, Temperature
STT and Trigeminal
a-Beta fibersProprioception and Fine touch
DC-ML and Trigeminal
Dorsal Column PathwayDRG: enters spinal cord and ascends ipsilaterally
1. Synapse N. Gracilus (<T6) and N. Cuneatus (>T6)
- Decussates at Caudal medulla and ascends contralaterally in Medial Lemniscis
2. Synapse at VPL (thalamus)
3. Sensory cortex
SpinoThalamic TractDRG: enters spinal cord and ascends Ipsilaterally
1. Synapse in the gray matter of spinal cord
- Decussates in the Anterior White Commissure
- Ascends contralaterally
2. Synapse at VPL (thalamus)
3. Sensory cortex
Lateral Corticospinal tract Pathway1. UMN: cell body in 1° motor cortex →
- descends ipsilaterally through internal capsule
- Decussates at caudal medulla (pyramidal decussation) → descends contralaterally
2. Cell body of Anterior Horn (spinal cord)
- LMN leaves spinal cord
3. Synapses at the NMJ


Question Answer
# of spinal nerves31 total:
8 Cervical
12 Thoracic
5 lumbar
1 coccygeal
Vertebral disc herniationnucleus pulposus (soft central disc) herniates through anulus fibrosus (outer ring)
usually posterolaterally at L4-L5 or L5-S1
Spinal cord extends to where?L1-L2
Subarachnoid space extends to where?Lower border of S2
Lumbar tap levelsL3-L5

Rapid Fire

Question Answer
Pressure, Vibration, ProprioceptionDC-ML
Pressure, Vibration, Proprioception > T6N. Cuneatus (DCML)
Pressure, Vibration, Proprioception < T6N. Gracilus (DCML)
Pain and Temperature SensationLateral SpinoThalamic Tract
Crude Touch and PressureAnterior SpinoThalamic Tract
Alternate route for voluntary movementReticulospinal and Rubrospinal
Postural adjustments and Head movementsVestibuloSpinal
Proprioception from the cerebellumDorsal and Ventral SpinoCerebellar
Voluntary motor command from Motor cortex to Contralateral BodyLateral Corticospinal tract
Voluntary motor command from Motor cortex to Ipsilateral BodyVentral Corticospinal tract
Voluntary motor command from Motor cortex to Head and neckCorticobulbar tract [Bulb = head]

Spinal cord lesions

DiseaseArea of destructionCharacteristics
Polio & Werdnig-Hoffman diseaseAnterior Horns
Corticospinal tract: Lose motor output
LMN lesions: Flaccid paralysis, Hyporeflexia, Fasciculation
Asymmetric limbs
MSCervical white matter: Random and Asymmetric
Charcot's triad: Scanning speech + Intention tremor + Nystagmus
Internuclear opthalmoplegia (MLF)
CSF: ↑ Protein (Ig light chains)
ALSAnterior horn and lateral corticospinal tracts
UMN (LCST): Spastic paralysis, Increased tone
LMN (Ant horn): Flaccid paralysis, Fasciculation, Weakness, Atrophy
No sensory loss!
Caused by defect in Superoxide Dismutase 1
Tx with Riluzole (modest ↑ in survival with ↓ presynaptic glutamate release)
Complete occlusion of anterior spinal arteryPreserve dorsal columns and Lissauer's tract
Loss of bilateral movement (CST), Pain/Temperature (STT) below lesion
Light touch, Vibration and Proprioception in tact
Lesion and deficits above T8 usually d/t lack of collateral blood supply above T8
Tabes dorsalisdorsal columns
Caused by 3° syphilis
Impaired sensation/proprioception and progressive sensory ataxia
+ Romberg (tests DCML)
Assoc w. Charcot's joints, shooting pain, Argyll Robertson pupils (small, bilateral pupils that accommodate but don't react)
SyringomyeliaAnterior white commissure
Impaired Spinothalamic Tract: Loss of bilateral pain/temp
Seen with Chiari 1
Usually C8-T1 but can expand
Vitamin B12 or Vit E deficiencyDemyelination of Dorsal Columns, Lateral CST, and Spinocerebellar tracts
Ataxic gait (Spinocerebellar, LCST)
Impaired position and vibration sense (Dorsal Column)
Brown SequardHemisection
- Below lesion: UMN (CST) and Vibration/Proprioception (DCML)
- At lesion: LMN (CST) and Loss of Sensation
- Loss of pain, temperature and crude touch (STT)


A great website:


Question Answer
spread of poliovirus in the bodyreplicates in oropharynx and small intestine, spreads via bloodstream to CNS
signs of poliovirus infectionmalaise, headache, fever, nausea
symptoms of poliomyelitisLMN signs (destruction of cells in anterior horn of spinal cord)
poliovirus can be recovered fromstool and throat
CSF findings in poliomyelitisincreased WBCs and slight protein elevation, no change in glucose
Werdnig-Hoffman disease iscongenital degeneration of anterior horns -> LMN lesion. floppy baby with tongue fasciculations.
inheritance of Werdnig-Hoffmanautosomal recessive
infantile Werdnig-Hoffman median age of death7 months
Friedreich's ataxia geneticsautosomal recessive GAA trinucleotide repeat
defect in Friedreich's ataxiafrataxin; leads to impairment of mitochondrial function
findings in Friedreich's ataxiastaggering gate, frequent falling, nystagmus, dysarthria, pes cavus, hammer toes
Friedreichs ataxia presents in childhood withkyphoscoliosis
cause of death in Friedreich's ataxiahypertrophic cardiomyopathy
symptoms of Horner's syndromeptosis, miosis, anhydrosis
oculosympathetic pathwayhypothalamus, intermediolateral column in spinal cord, superior cervical ganglion, to eye area

Landmark Dermatomes & reflexes

Question Answer
C2posterior half of skull
C3high turtleneck shirt
C4low collar shirt
T7xiphoid process
L1inguinal ligament
S2, S3, S4erection and sensation of penile and anal zones
primitive reflexes normally disappear within 1st year of life, inhibited byfrontal lobe; frontal lobe lesion may cause reemergence of primitive reflexes
moro reflexabduct/extend limbs when startled, then draw together
rooting reflexmovement of head toward one side if cheek or mouth stroked (nipple seeking)
sucking reflexsucking response when roof of mouth is touched
palmar reflexcurling of fingers if palm is stroked
gallant reflextrekking one side of spine while newborn face down causes lateral flexion of lower body toward stimulated side


Question Answer
CNs that lie medially at brainstemIII, VI, XII
Pineal glandMelatonin secretion
Circadian rhythms
Superior colliculiVertical gaze center
inferior colliculiAuditory
Parinaud syndromeParalysis of upward gaze
- Due to lesion in superior colliculi (e.g., pineal germinoma)
CN Ismell, only CN without thalamic relay
CN IIsight
pupillary constriction (sphincter pupillae; Edinger-Westphal nucleus, muscarinic receptors)
eyelid opening (levator palpebrae)
CN Vmastication, facial sensation, somatosensation from anterior 2/3 of tongue
CN VIIfacial movement
taste from anterior 2/3 tongue
salivation (submandibular and sublingual)
eyelid closing (orbicular oculi)
stapedius muscle in ear
CN VIIIhearing, balance
CN IXtaste and somatosensation from posterior 1/3 of tongue
salivation (parotid)
carotid body and sinus
CN Xtaste from epiglottic region
palate elevation
midline uvula
thoracoabdominal viscera
aortic arch chemo and baroreceptors
CN XISCM, trapezius
CN XIItongue movement
Midbrain nucleiII, IV
Pons nucleiV, VI, VII, VIII
medulla nucleiIX, X, XII
spinal cord nucleiXI
corneal reflexafferent is V1 nasociliary branch; efferent is VII temporal branch (orbicularis occuli)
lacrimationafferent V1 (loss of reflex does not preclude emotional tears); efferent VII
jaw jerkafferent V3 muscle spindle from masseter; efferent V3 to masseter
pupillaryafferent II, efferent III
gagafferent IX, efferent X
nucleus solitarius informationvisceral sensory, e.g., tate, baroreceptors, gut distention
nucleus solitarius CNsVII, IX, X
nucleus ambiguus infomotor innervation of pharynx, larynx, upper esophagus
nucleus ambiguus CNsIX, X
dorsal motor nucleus infoparasympathetic fibers to heart, lungs, upper GI
dorsal motor nucleus CNsX

CN pathways

Question Answer
cribriform plateCN I
middle cranial fossa through sphenoid boneCN II-VI
optic canalCN II, ophthalmic artery, central retinal vein
superior orbital fissureIII, IV, V1, VI, ophthalmic vein, sympathetic fibers
foramen rotundumV2
foramen ovaleCN V3
foramen spinosummiddle meningeal artery
posterior cranial fossa through temporal or occipital boneVII-XII
internal auditory meatusVII, VIII
jugular foramenIX, X, XI, jugular vein
hypoglossal canalXII
foramen magnumspinal roots of XI, brain stem, vertebral arteries
Great mnemonic for CN exit sitesCarl only swims south. Silly Roger only swims in infinity jaccuzzi's. Jane just hitchhikes
passage of blood through venous sinusblood from eye and superficial cortex -> cavernous sinus -> internal jugular
things that run through cavernous sinusII, IV, V1, V2, VI, postganglionic sympathetics, internal carotid
cavernous sinus syndromeophthalmoplegia and decreased corneal and maxillary sensation, normal vision

Common CN lesions

Question Answer
CN V motor lesionjaw juts toward lesion (unopposed force of opposite pterygoid)
CN X lesionuvula deviates away from lesion (weak side collapses)
CN XI lesionweakness turning head to contralateral side (SCM), shoulder droop on ipsilateral side (trapezius)
CN XII lesion (LMN)tongue deviates toward lesion (lick your wound)

Hearing loss & facial lesions

Question Answer
conductive hearing loss rinneabnormal (bone > air)
conductive hearing loss weberpt hears the sound louder in the affected ear
sensorineural rinnenormal (air > bone)
sensorineural weberlouder in unaffected ear
noise-induced hearing loss damagestereocilliated cells in organ of Corti; high-frequency lost first
UMN lesionLesion between motor cortex and facial nucleus
Contra paralysis of lower face
forehead spared d/t bilateral innervation by UMNs
LMN lesionIpsi paralysis of upper & lower face
Facial nerve palsyIpsi facial paralysis w inability to close eye on involved side
Occurs in: AIDS, Lyme disease, HSV, sarcoid, tumors, and diabetes
Weber test256 Hz tuning fork is placed on the forehead
Rinne test512Hz tuning fork placed on mastoid bone. Once the vibration is no longer heard, quickly move tuning fork to just outside the ear canal. If they can hear it again, normal (air conduction should be better than bone)

Mastication muscles

Question Answer
muscles that close jawmasseter, temporalis, medial pterygoid
muscle that opens jawlateal pterygoid
all mastication muscles innervated byV3