Strokes Brain Lesions

xadajavo's version from 2016-08-08 05:15

Common Brain Lesions

Question Answer
Frontal lobe functionsdamage--> disinhibition, planning, language, judgment, mood, social judgement
deficits in concentration and possible reemergence of primitive reflexes
Lesion of amygdalakluver-bucy syndrome- hyperorality, hypersexuality, disinhibited behavior
Lesion right parietal lobespatial neglect syndrome, agnosia of contralateral world
Lesion RAS in midbrainreduced arousal and wakefulness
Lesion mamillary bodiesWernicke-korsakoff- confusion/ophthalmoplegia/ataxia AND memory loss/confabulation/personality change, seen in alcoholics (thiamine def)
Lesion BGmay result in resting tremor, chorea, or athetosis
Lesion cerebellar hemisphereintention tremor, limb ataxia
damage results in ipsilateral deficit → fall towards side of lesion
Lesion cerebellar vermistruncal ataxia, dysarthria
Lesion subthalamic nucleushemiballismus (contralateral)
Lesion hippocampusanterograde amnesia (cant make new memories)
Lesion PPRFeyes look away from side of lesion
Lesion Frontal eye fieldeyes look toward lesion

CPM & aphasias

Question Answer
Central pontine myelinolysis sxsacute paralysis, dysarthria, dysphagia, diplopia and LOC
Central pontine myelinolysis pathcaused by very rapid correction of hyponatremia usually
Massive axonal demyelination in pontine white matter tracks
Abnormal inc. signal in the pons in T2-weighted MRI
Recurrent laryngeal n. injurylose all laryngeal mm. except cricothyroid, hoarseness
Broca's aphasianonfluent aphasia with intact comprehension, broken boca, INFERIOR FRONTAL GYRUS (frontal lobe)
Wernicke''s aphasiareceptive aphasia, fluent but impaired comprehension, SUPERIOR TEMPORAL GYRUS (temporal lobe)
Conduction aphasialesion arcuate fasciculus connecting broca/wernicke
poor repetition but intact speech and comprehension
Lesion to non-dominant Broca's areaExpressive Dysprosody. Inability to express emotion of inflection in speech. right hemisphere
Lesion to non-dominant Wernicke's areaReceptive Dysprosody. Inability to comprehend emotion. right hemisphere

How to localize a brainstem lesion

Question Answer
cranial nerves in midbrainIII and IV
cranial nerves in ponsV, VI, VII, IIX
cranial nerves in medullaIX, X, XII
cranial nerves in midlinesare those that divide into 12
medial structuresstart with an M
lateral structures startwith an S
corticospinal pathway (aka motor pathway)medial
medial lemniscusmotor pathway
loss of vibration/propioception in contralateral arm and legmedial leminiscus
MLFipsilateral INO
spinocerebllaripsilateral arm and leg ataxia
spinothalamicpain and temperature in contralateral arm and leg
sympatheticipsilateral Horner's
corticospinalweakness contralateral arm and leg

Blood supply


Question Answer
Blood supply to medial portions of the cortex down deep in the longitudinal fissure along corpus callosumACA
Leg/foot region of Sensory homunculusACA
Foot region of Sensory homunculusACA
Leg region of Motor homunculusACA
Foot region of Motor homunculusACA
contralateral paralysis lower limbACA
contralateral loss of sensation lower limbACA
Blood supply to the lateral aspect of the primary motor and sensory cortexMCA
Bloody supply to Broca's AreaMCA
Face region of Sensory homunculusMCA
Hand region of Sensory homunculusMCA
Face region of Motor homunculusMCA
Hand region of Motor homunculusMCA
contralateral paralysis upper limb and faceMCA
aphasia if in dominant (usually left)MCA
hemineglect if lesion affects non dominant (right)MCA
contralateral loss of sensation upper limb and faceMCA
Blood supply to occipital lobe - visual cortexPCA
Expressive AphasiaMCA: Broca's Aphasia
Receptive AphasiaMCA: Wernicke's Aphasia
Blood supply to Broca's areaMCA
Blood supply to Wernicke's areaMCA
Hemianopia with macular sparingPCA, occipital cortex
MCA suppliesUpper limb and Face: Motor and Sensory cortex
Temporal lobe: Wernicke's
Frontal lobe: Broca's
ACA suppliesLower limb: Motor and Sensory cortex
PCA suppliesOccipital cortex, Visual Cortex
ASA suppliesLCST
Medial lemniscus
Caudal medulla: Hypoglossal
PICA suppliesLateral medulla
AICA suppliesLateral pons, Middle and inferior cerebellar peduncle
Contralateral paralysis and loss of sensationACA
Locked inBasilar artery Pons and below
Wallenberg syndromePICA
- Dysphagia, Hoarseness, impaired Gag
- Ipsilateral face: Pain/temperature loss
- Contralateral body: Pain/temperature loss
- Vomting, Vertigo, Nystagmus
Medial medullary syndromeASA
- Contralateral hemiparesis (upper/lower)
- Contralateral proprioception
- Tongue deviates ipsilateral
Lateral pontine syndromeAICA facial paralysis
- Decreased lacrimation
- Ipsilateral face: pain and temperature loss
- Contralateral body: Pain and temperature

Cortex Lesions

Question Answer
Aphasia w intact comprehensionBroca's Aphasia
"Fluent" AphasiaWernicke's Aphasia
Aphasia with impaired comprehensionWernicke's Aphasia
Aphasia w intact comprehensionConduction Aphasia
Aphasia with poor repetitionConduction Aphasia
Aphasia due to lesion of arcuate fasciculusConduction Aphasia
Arcuate fasciculusTract that connects Broca's and Wernicke's area
Non-fluent aphasia AND Impaired comprehensionGlobal Aphasia
Lesion to non-dominant Broca's areaExpressive Dysprosody. Inability to express emotion of inflection in speech.
Lesion to non-dominant Wernicke's areaReceptive Dysprosody. Inability to comprehend emotion

Common Brain Lesions

Question Answer
Lesion to dominant angular gyrus in parietal lobe (posterior, superior to Wernicke's area)Gerstmann syndrome
AgraphiaGerstmann syndrome
AlcalculiaGerstmann syndrome
Right-left disorientationGerstmann syndrome
Finger agnosiaGerstmann syndrome
Lesion to non-dominant parietal lobeHemispatial neglect
Frontal cortex lesionDishinibtion, Poor judgment, Reemergence of primitive reflexes
Prefrontal cortex lesionPt. unable to complete complex higher level tasks
Lesion to PPRF - eye deviates......away from side of lesion
Lesion to Frontal eye field - eye deviates......toward side of lesion
Lesion to superior colliculusParalysis of upward gaze (Parinaud's Syndrome)
Lesion to Reticular activating systemStupor and coma
Bilateral hippocampus lesionAnterograde amnesia
Destruction of mammillary bodiesWernicke-Korsakoff syndrome (Anterograde &or retrograde amnesia, ataxia, nystagmus, confabulation)
Bilateral amygdala lesionKl├╝ver-Bucy syndrome. Associated with HSV-1
Lesion to basal gangliaHypokinesis or hyperkinesis
Lesion to subthalamic nucleus of basal gangliaHemiballismus (involuntary flailing of arm)
Hemispheric cerebellar lesionIpsilateral movement problems
Cerebellar vermis lesionTruncal ataxia, dysarthria
spastic paralysisUMN lesion
flaccid paralysisLMN lesion
clasp knifespaciticity (UMN)
mutation in superoxide dismutase 1ALS
lesion to internal capsulemotor deficit
thalamic syndrometotal sensory loss on contralateral side of body



Question Answer
Anterior spinal a.Lateral corticospinal tract - contralateral hemiparesis of lower limbs
ML - no contra proprioception
Caudal medulla - ipsilateral paralysis of hypoglossal n. - tongue deviates ipsilaterally
PICA occlusionLateral medulla
Vestibular nuclei - vomiting, vertigo, nystagmus
lateral spinothalamic tract, spinal trigeminal nucleus - ↓ pain/temp in limbs/face
nucleus ambiguus - dysphagia, hoarseness ↓ gag reflex
Sympathetics - ispilateral Horner's
ICP - ataxia, dysmetria
"Don't PICA horse that can't eat"
AICA occlusionLateral pons:
CN nuclei - vomiting, vertigo, nystagmus, paralysis of face, ↓ lacrimation/salivation, ↓ taste from anterior 2/3rds of tongue, ↓ corneal reflex
Ipsi ↓ pain/temp/hearing, horner's
MCP/ICP - ataxia, dysmetria
"Facial droop means AICA's pooped"
PCA occlusionOccipital cortex, visual cortex:
contra homonymous hemianopia with macular sparing
ACA occlusionContra lower limb paralysis and loss of sensation
MCA occlusioncontra face/arm paralysis and sensory loss
aphasia (if lesion on left side)
left sided neglect (if lesion on right side)
Anterior communicating a.most common site of saccular (berry) neurysm in Willis
visual field defects
Posterior communicatingn a. occlusionSaccular (berry aneurysm)
CN3 palsy - eye is "down and out" w pupil dilation
Lateral striate aa. occlusiondivisions of MCA, supply internal capsule, striatum(caudate/putamen)
contralateral hemiparesis/hemiplegia
lacunar infarcts (2° to unmanaged hypertension)
Watershed zonesbetween ACA/MCA, and PCA/MCA
damage in severe hypotension-->upper leg/upper arm weakness, defects in high-order visual processing
Basilar a. infarctlocked in syndrome, only CN3 works
Stroke of anterior circlegeneral sensory/motor dysfunction, aphasia
Stroke of posterior circledeficit in CNs, coma, cerebellar deficits, dominant hemisphere (ataxia), nondominant (neglect)
Cerebral perfusion regulated byPCO2, except in severe hypoxia (severe COPD) - then PO2 takes over
Medial medullary syndromeparamedian branches of ASA and vertebral arteries
Contra LL hemiparesis
↓ contra proprioception
Tongue deviation toward lesion
Lateral medullary (Wallenberg's) syndromePICA (lateral medulla)
CN deficits
Dysphagia, hoarseness, ↓ gag reflex
Ipsi Horner's
Most common site of Berry aneurysmbifurcation of the anterior communicating a.
sx of berry aneurysm rupture"worst headache of my life" d/t subarachnoid hemorrhage
Bitemporal hemianopia via compression of optic chiasm
Associated with berry aneurysmADPKD
Ehler's Danlos syndrome
Marfan's syndrome
Advanced age, HTN, smoking, AAs
Charcot-Bouchard microaneurysmChronic hypertension
Small vessels - basal ganglia, thalamus


Question Answer
most common site of saccular (aka Berry aneurysm)junction of acom and ACA
increased in ADPKD and Ehlers Danlosberry aneurysms
Pcomm aneurysmCN III palsy (down and out with ptosis and mydriasis)
ruptured berry aneurysmsubarachnoid hemorrhage
bitemporal hemianopiacompression of optic chasm by berry aneurysm
common between Acomm and ACAberry aneurysms
lenticulostriate vesselslacunar infarct
associated with HTNlacunar and charcot-bouchard
common in basal gangliacharcot-bouchard micro aneurysm (intracerebral hemorrhage)
intracerebral hemorrhagecharcot-bouchard
middle meningeal artery ruptureepidural
bridging veins rupturesubdural
blood between dura and skullepidural
lucid intervalepidural
fracture to temporal boneepidural
talk and die syndromeepidural
blood between dura and arachnoidsubdural
crescent shaped hemorrhagesubdural
crosses suture linessubdural
does NOT cross suture linesepidural
crosses falx tentoriumepidural
does NOT cross falx tentoriumsubdural
may begin days to week after traumasubdural
momentary loss of consciousness followed by lucid intervalepidural
lens shapedepidural
crescent shapedsubdural
AV malformationsubarachnoid
xanthochromic spinal tapblood or yellow (subarachnoid)
amyloid angiopathyintraparenchymal hemorrhage
premature babiesintraventricular hemorrhage of germinal matrix
risk of vasospasm due to rebelledsubarachnoid
most vulnerable to ischemic hypoxiahippocampus (pyramidal neurons 3, 5, 6) and also cerebellum (parkinje)
ependymal cellsmake CSF
vitamin A excesspseudotumor cerebri
distorts fibers of corona radiatanormal pressure hydrocephalus
wet wobbly wackynormal pressure hydrocephalus
reversible hydrocephalusnormal pressure (reverses with VP shunt)
internal capsule strokemotor deficit
thalamic syndrometotal sensory loss on contralateral side of body

Quick associations

Question Answer
basilar arterypons
PCAtemporal, occipital
MCAtemporal, parietal, frontal, insular cortex
ACAparietal and frontal

Ischemic Brain Disease/Stroke

Question Answer
red neurons12-24 hours
necrosis and neutrophils24-72 hours
macrophages (microglia)3-5 days
reactive gliosis plus vascular proliferation1-2 weeks
glial scargreater than 2 weeks
most vulnerable region of the brain to hypoxiahippocampis
irreversible injury beginsfive minutes after hypoxia
hippocampusmust vulnerable to hypoxia

Hydrocephalus etc

Question Answer
Pseudotumor cerebriincreased ICP with no apparent cause on imaging. Papilledema seen on exam.
Communicating hydrocephalusincreased ICP and decreased CSF absorption by arachnoid granulations. enlargement all parts of ventricular system
NPHdminshed resportive capativy of arachnoid villi. CT shows communication, but LP shows normal opening pressures
NPH clinical presentationwet, wobbly and wacky
CT/ MRI of NPHcommunicating hydrocephalus, LP shows normal opening pressure
non communicationblockage CSF circulation
ex vacuo ventriculomegalyappearance of increased CSF on imaging. neuronal atrophy. ICP is normal
Increased ICPpseudotumor cerebri, communicating hydrocephalus
obstruction at foramen Magendie and Lusckhaenlargement of all four ventrilces
obstruction at cerebral aqueductdilated lateral and third ventricles. normal 4th
obstruction at foramen of monroenlargement of only affected lateral ventricle

urination reflex and NPH

Question Answer
sacral micturition centerlocated in S2-S4 and responsible for bladder contraction via parasympathetics
pontine micturitionlocated in pontine reticular formation. Coordinates external urethral sphincter w/bladder contraction during voiding
cerebral cortexinhibits sacral center
NPHdisrupts impules from cortex to sacral center. later in the disease, there is lack of inhibition from cerebral cortex

dopaminergic pathways

Question Answer
meso-limbic-meso-corticalregulates behavior
nigrostriatalcoordination of voluntary movements
tuberoinfundibularcontrols prolactin secretion
disease associated with meso-limbic mesocorticalschizophrenia
disease associated with nigrostriatalParksonism
disease associated with tuberoinfundibularhyperprolacitnemia