Neuro Arterial Supply Flashcards by Ali Haselhorst

What are the Watershed zones of the Cebral arteries?

Between Anterior/middle cerebral arteries & Posterior/middle cerebral arteries

How well did you know this?

Not at all

Perfectly

What is the consequence of severe hypotension in the Watershed zones?

Upper leg/upper arm weakness, defects in higher-order visual processing

How well did you know this?

Not at all

Perfectly

What is Cerebral perfusion primarily driven by?

PCO2

(PO2 in severe hypoxia)

How well did you know this?

Not at all

Perfectly

What is Therapeutic hyperventilation (dec PCO2) used for?

Helps dec ICP in cases of acute cerebral edema (stroke, trauma) via dec cerebral perfusion

How well did you know this?

Not at all

Perfectly

What are the effects of a stroke in the MCA area of the Motor cortex?

Contralateral paralysis of the upper limb & face

How well did you know this?

Not at all

Perfectly

What are the effects of a stroke in the MCA area of the Sensory cortex?

Contralateral loss of sensation in upper limb & face

How well did you know this?

Not at all

Perfectly

What are the effects of a stroke in the MCA area of the Temporal lobe (Wernicke’s area) or Frontal lobe (Broca’s area)?

Aphasia if in dominant (us. left) hemisphere

Hemineglect if lesion in nondominant (us. right) side

How well did you know this?

Not at all

Perfectly

What are the effects of a stroke in the ACA area of the Motor cortex?

Contralateral paralysis in the lower limb

How well did you know this?

Not at all

Perfectly

What are the effects of a stroke in the ACA area of a Sensory cortex?

Contralateral loss of sensation in the lower limb

How well did you know this?

Not at all

Perfectly

What are the effects of a stroke in the Lateral striate artery area of the Striatum or internal capsule?

Contralateral hemiparesis/hemiplegia

How well did you know this?

Not at all

Perfectly

What are the effects of a stroke in the ASA area of the Lateral corticospinal tract?

Contralateral hemiparesis of lower limbs

Stroke commonly bilateral

How well did you know this?

Not at all

Perfectly

What is Medial medullary synd?

Caused by infarct of paramedian branches of ASA & vertebral arteries

How well did you know this?

Not at all

Perfectly

What are the effects of a stroke in the ASA area of Medial Leminsucs?

Dec contralateral proprioception

How well did you know this?

Not at all

Perfectly

What are the effects of a stroke in the ASA area of the Caudal medulla (hypoglossal n.)?

Ipsilateral hypoglossal dysfunction

(tongue deviates ipsilaterally)

How well did you know this?

Not at all

Perfectly

What are the structures of the lateral medulla?

Vesibular nuclei
Lateral Spinothalamic tract
Spinal trigemeinal nucleus
Nucleus ambiguus
Sympathetic fibers
Inferior cerebellar peduncle

How well did you know this?

Not at all

Perfectly

What are the effects of a stroke in the PICA area of the Lateral medulla?

Dysphagia*
Hoarseness*
Vomiting
Vertigo
Nystagumus
Dec pain & temp sensation to limbs/face
Dec gag reflex
Ipsilateral Horner’s synd
Ataxia
Dysmetria

How well did you know this?

Not at all

Perfectly

What synd can stroke to the PICA area of the Lateral medulla cause?

Lateral medullary (Wallenburg’s) synd

How well did you know this?

Not at all

Perfectly

What are the effects of a stroke to the AICA area of the Lateral pons?

Paralysis & loss of pain/temp sensation of face*
Vomiting
Vertigo
Nystagmus
Dec lacrimation
Salivation
Dec taste from anterior 2/3 of tongue
Dec corneal reflex
Ipsilateral loss of hearing/Horner’s synd

How well did you know this?

Not at all

Perfectly

What are the structures of the Lateral pons?

Cranial nerve
Vestibular nuclei
Facial nucleus
Spinal trigeminal nucleus
Cochlear nuclei
Sympathetic fibers

How well did you know this?

Not at all

Perfectly

What are specific to PICA lesions?

Nucelus ambiguus effects

How well did you know this?

Not at all

Perfectly

What are specific to AICA lesions?

Facial nucleus effects

How well did you know this?

Not at all

Perfectly

What are the stroke effects of a stroke in the AICA area of the Middle & Inferior cerebellar peduncles?

Ataxia & dysmetria

How well did you know this?

Not at all

Perfectly

What are the effects of a stroke in the PCA area of the Occipital cortex or Visual cortex area?

Contralateral hemianopia w/ macular sparing

How well did you know this?

Not at all

Perfectly

Whare are the common sites of saccular (berry) aneurysms?

PComm & AComm (impingement on cranial nerves)

How well did you know this?

Not at all

Perfectly

What are the effects of a AComm saccular (berry) aneurysm?

Visual field defects

What are the effects of a PComm saccular (berry) aneurysm?

CN III palsy-- eye is "down & out" w/ ptosis & pupil dilation

What is an aneurysm?

ABN dilation of artery dute to weaking of vessel wall

What is a Berry aneurysm?

Occurs at the bifurcations in the circle of Willis

What is the MC site of Berry aneurysm?

Bifurcation of the anterior communicating artery

What is the MC complication of a Berry aneurysm?

Rupture leads to subarachnoid hemorrhage ("worst headache of life") or hemorrhagic stroke

What can Berry aneurysm cause?

Bitemproal hemianopia via compression of optic chiasm

What are Berry aneurysms assoc w/?

* ADPKD * Ehlers-Danlos synd * Marfan's synd

What are the risk factors of a Berry aneurysm?

* Advanced age * HTN * Smoking * Race (high risk in blacks)

What is Charcot-Bouchard mircoaneurysm?

Assoc w/ chronci HTN Affects small vessels

What is an Epidural hematoma?

Rupture of Middle Meningeal artery (branch of maxillary a.), often 2° to a fracture of temporal bone

What do Epidural hematomas cause?

Lucid Interval Rapid expansion under systemic arterial pressure→ transtentorial herniation, CN III palsy

What does CT of an Epidural hematoma show?

Biconvex (lentiform), hyperdense blood collection not crossing suture lines. Can cross falx, tentorium

What is a Subdural hematomoa?

Rupture of bridging veins

What does a Subdural hematoma lead to?

Slow venous bleeding (less pressure= hematoma develops over time)

Who are Subdural hematomas seen in?

* Elderly * Alcoholics * Blunt trauma * Shaken baby

What is seen on CT of a Subdural hematoma?

Cresecent-shaped hemorrhage that crosses suture lines. Midline shift. Cannot cross the falx, tentorium

What is a Subarachnoid hemorrhage?

Rupture of an aneurysm or an arteriovenous malformation (AVM)

What does a Subarachnoid hemorrhage cause?

Rapid time course Pts complain of "worst headache of my life" (WHOML)

What is seen on spinal tap of a Subarachnoid hemorrhage?

Bloody or yellow (xanthochromic)

What are the risks 2-3 days after a Subarachnoid hemorrhage?

Risk of vasospasm d/t blood breakdown (not visible on CT, tx w/ nimodipine) & rebleed (visible on CT

What is the MC of Intraparenchymal (hypertensive) hemorrhage?

Systemic HTN

What can Intraparenchymal hemorrhage be seen in?

* Amyloid angiopathy * Vasculitis * Neoplasm

Where does Intraparenchymal hemorrhage occur?

Typically Basal ganglia & internal capsule but can be lobar

What can Athersclerosis cause?

Thrombi lead to ischemic stroke w/ subsequent necrosis Form cystic cavity w/ reactive gliosis

What is a Hemorrhagic stroke?

Intracranial bleeding

What can cause Hemorrhagic stroke?

* HTN * Anticoagulation * Cancer (ANB vessels can bleed)

What can a Hemorrhagic stroke be 2° to?

Ischemic stroke followed by reperfusion (Inc vessel fragility)

What is Ischemic brain dz/stroke?

Irreversible damage begins after 5 min of hypoxia

What areas of the brain are most vulnerable to Ischemic brain dz/stroke?

* Hippocampus * Neocortex * Cerebellum * Watershed areas

What is the time frame of irreversible nueronal injury?

* Red neurons (12-24 hours) * Necrosis + neutrophils (24-72 hours) * Macrophages (3-5 days) * Reactive gliosis + vascular prolif (1-2 weeks) * Glial scar (\>2 weeks)

What does a stroke show on diffusion-wt MRI?

Bright in 3-30 min & remains bright for 10 days

What does a stroke show on noncontrast CT?

Dark in ~24 hours Bright areas indicate hemorrhage (tPA contraindicated)

What is an Ischemic stroke?

Atherosclerotic emboli block large vessels

What can cause an Ischemic stroke?

* Atrial fibrillation * Carotid dissection * Patent foramen ovale * Endocarditis

What are Lacunar strokes?

Ischemic strokes that block small vessels May be 2° to HTN

What is the tx of an Ischemic stroke?

tPA w/in 4.5 hours (so long as pt presents w/in hours of onset & there is no major risk of hemorrhage)

What is a Transietn ischemic attack (TIA)?

Brief, reversible episode of focal neurologic dysfunction typically lasting \<1 hour w/o acute infarction (neg MRI)

What are the deficits in a TIA d/t?

Focal ischemia

What are the Dural venous sinuses?

Large venous channels that run through the dura

What do the Dural venous sinuses do?

Drian blood from cerebral veins & receive CSF from arachnoid granulations

Where do the dural venous sinuses empty?

Internal jugular vein

Where is CSF made?

Ependymal cells of choroid plexus

What is CSF reabsorbed by?

Arachnoid granulations

Where does CSF drain?

Dural venous sinuses

Where does the Lateral ventricle drain?

3rd ventricle via right & left intraventricular foramina of Monro

Where does the 3rd ventricle drain?

4th ventricle via cerebral aqueduct of Sylvius

Where does the 4th ventricle drain?

Subarachnoid space via Foramina of Luschka (lateral) & Foramen of Magendie (medial)

What is Communicating hydrocephalus?

Dec CSF absorption by arachnoid granulations, which can lead to inc ICP, papilledema & herniation

What is normal pressure hydrocephalus?

Results in inc subarachnoid space volume but no inc in CSF pressure. Expansion of ventricles distorts the fibers of the corona radiata.

What is the Clinical Triad of normal pressure hydrocephalus?

Urinary incontinence, ataxia & cognitive dysfunction "Wet, wobbly & wacky"

What is Hydrocephalus ex vacuo?

Appearance of inc CSF in atrophy

What dz are hydrocephalus ex vacuo seen in?

* Alzheimer's dz * Advanced HIV * Pick's dz

What are the clinical features of Hydrocephalus ex vacuo?

ICP normal & triad not seen

What is seen on imaging in Hydrocephalus ex vacuo?

Apparent increase in CSF observed on imaging is actually result of dec neural tissue d/t neuronal atrophy

What causes Noncommunicating hydrocephalus?

Structural blockage of CSF circulation w/in the ventricular system

Neuro Arterial Supply Flashcards

(80 cards)