CAPLAN CH8: POST CIRC Flashcards
T/F. Most patients with subclavian artery disease are asymptomatic.
TRUE. Though some present with fatigue, aching after exercise and coolness
In patients with subclavian stenosis, neurological symptoms are NOT common unless ___.
There is accompanying carotid artery disease.
A. What is the most frequent symptom of SUBCLAVIAN ARTERY DISEASE?
B. What is the most frequent NEUROLOGICAL symptom of SUBCLAVIAN ARTERY DISEASE?
A. Those related with ipsilateral arm and hand (eg coolness, weakness and pain)
B. Dizziness (that is spinning or vertiginous in character)
Characteristic pulse of patients with SUBCLAVIAN occlusion.
smaller volume, and delayed relative to the contralateral arm,
bruit from ECVA stenosis WITHOUT subclavian artery narrowing, inflating a BP cuff above systolic BP may ___ the bruit.
AUGMENT (by directing more blood into the ECVA)
When a bruit is caused by SUBCLAVIAN or INNOMINATE artery stenosis, inflating the cuff, ___.
REDUCES flow into the arm, hence the bruit becomes SOFTER.
Where can you find most SUBCLAVIAN ARTERY STENOSIS?
Left more than the right.
Proximal to the VA more often involved.
Professions at risk for INNOMINATE and SUBCLAVIAN ARTERY disease:
Baseball pitchers
Cricket Howlers
Identify which blood vessel involved:
ipsilateral arm and eye ischemia
anterior or posterior circulation (or both) ischemia
INNOMINATE ARTERY DISEASE
Why is the RIGHT SUBCLAVIAN more problematic than the left?
The proximal right subclavian artery makes a posterolateral curve.
Why is it important to obtain delayed films of ECVA when angiography is performed?
Retrograde phase of flow might be missed.
When is repair indicated in subclavian artery occlusions?
- Patient is incapacitated by arm ischemia
- Affects the right innominate or subclavian, serious carotid, territory infarction can ensue.
Otherwise, watchful waitiing
The most frequent location for atherosclerotic disease of the ECVA is at___.
Their origin from the subclavian arteries.
Patients with VA occlusion are indistinguishable from patients with subclavian steal EXCEPT FOR___.
ECVA- origin TIAs are not precipitated by effort or by arm exertion.
ECVA occlusion can be a good differential in patients with ____ dizziness.
repeated, unaccompanied dizziness
Remember that BPPV is only present on rising and retiring
Description of ECVA lesions:
fibrous and smooth; seldom ulcerate
Why are there only scant pathologic data on ECVA-origin lesions?
Endarterectomy is not often performed, so the vessel is not available for pathological examination.
Differentiate ECVA and ICA in terms of origin:
ECVA: arises at nearly 90 degrees
ICA: a direct 180 degree extension
Most important presentation of ECVA-origin disease
Embolization of white platelet-fibrin and red erythrocyte-fibrin thrombi from atherostenotic occlusive lesions
Give TWO reasons why ECVA- origin lesions seldom cause chronic, hemodynamically significant low flow to the vertebrobasilar system:
1, VA are paired uniting to form a single basilar artery (rare atresia of a VA)
2. ECVA gives off numerous muscular and other branches as it ascends (remember ICA has no nuchal branches)
In patients with proximal ECVA disease, a bruit can often be heard over the ___.
SUPRACLAVICULAR REGION. Physicians should auscultate by moving the stethoscope bell to listen over the POSTERIOR CERVICAL MUSCLES, MASTOID.
Most effective means of monitoring ECVA blood flow?
CW Doppler insonation in the low neck and at the C2 region
Restenosis rate of angioplasty and stenting of ECVA?
9-10% within one year
Which part of the vertebral artery is within the intervertebral foramina?
V2 portion
Trial that demonstrated ECVAs treated with stenting developiing restenosis more than 50% at 6 months follow-up.
SSYLVIA TRIAL
Stenting of Symptomatic Atherosclerotic Lesions in the Vertebral or Intracranial Arteries
Treatment for patients with proximal ECVA disease?
Not established yet.
LRC chooses warfarin; JSK uses aspirin + clopidogrel
Usual locations of vertebral artery dissections?
V1- proximal portion of the ECVA
V3- distal extracranial portion, MOST COMMON
Pain is a common presentation of verebral artery dissection? YES OR NO.
YES. Remember that pain in the posterior neck, occiput, and generalized headache is common. Usually hours, rarely weeks.
Typical duplex scan findings of the ECVAs that suggest dilatation:
Increased arterial diameter
Decreased pulsatility
Intravascular abnormal echoes
hemodynamic evidence of decreased flow
Features predictive of a good prognosis for a VAD?
Pain as presentation
No or minor neurological siigns
TIAs are less common in ECVA dissections than in ICA dissections? YES or NO.
YES.
Commonest patterns of ischemic brain damage from VAD?
Cerebellar infarction in the PICA territory distribution and
Lateral medullary infarction
How can ECVA dissections cause cervical root pain?
When an aneurysmal dilatation of the ECVA adjacent to nerve roots causes the radicular pain and can lead to radicular distribution motor, sensory and reflex abnormalities.
What is still the optimal method of imaging the extracranial vertebral arteries in patients suspected of having VAD?
dye-contrast catheter cerebral angiography
What is the most common vascular lesion explaining the lateral medullary syndrome?
occlusion of the proximal or middle portion of the ICVA
Describe the nystagmus of patients with lateral medullary syndrome?
with coarse rotatory movement
when looking at the ipsilateral side- SMALL- AMPLITUDE
when looking at the contralateral side- LARGE- AMPLITUDE
sometimes, there is ocular lateral pulsion
Describe the sensory loss in LATERAL MEDULLARY SYNDROME?
In the limbs, it is ANALGESIA- CONTRALATERAL.
The leg is worse than the arm. (It is because sacral area– leg– trunk– arm are arranged from superficial to medial).
LOSS OF VIBRATION SENSE IS- IPSILATERAL
Associated with caudal lesions extending dorsomedially involving dorsal column or decussating lemniscal fibers.
Differentiate ROSTRAL vs CAUDAL medullary infarctions?
ROSTRAL- more associated with distal artery atherosclerotic disease (ventral paramedian area affected)
Hence, dysphagia, dysarthria, contralateral trigeminal sensory loss, and facial palsy.
CAUDAL- laterally located.
Hence, more severe gait ataxia, more lower extremity involvement due to spinocerebellar tract
Lateral Medullary Syndromes usually have good prognosis EXCEPT for:
- If extended and affects ipsilateral cerebellum
- If respiratory centers are affected (hence sudden death)
- If both ICVAs are occluded
Mechanism of a hemimedullary infarction?
Long occlusion of the distal ICVA (that spares the PICA)
Territory of SCA and PICA/AICA is separated by what?
The horizontal fissure (above is SCA, below is PICA/AICA)
Important PICA symptoms:
alteration of posture
gait ataxia
limb hypotonia
(note that ipsilateral limbs do not show a cerebellar type of rhythmic intention tremor)
What is the general rule in ICVA disease?
The more distal it is along the path from the proximal subclavian-vertebral junction to the distal basilar artery, the more likely it is to cause infarction.
The more proximal, the more benign.
What are the most common symptoms of an AICA infarct?
dysarthria, limb dysmetria and intention tremor
What do you call eyelid retraction. Common in patients with lesions at the midbrain-thalamic junction.
Collier sign.
In how many percent, the basilar communicating artery is hypoplastic?
30%
What is the most common mechanism of infarction in PCA strokes?
embolism from a proximal occlusive lesion within the vertebrobasilar system
When intrinsic atherosclerosis of the PCA is present, the clinical presentation usually consists of ___.
transient hemianopic visual symptoms, sometimes accompanied by transient hemisensory symptoms on the same side.
Describe the headaches caused by PCA disease?
Found retro-orbital or above the eye
- reflecting the fact that the upper surface of the tentorium is innervated by the first division of the CNV
Affected in SUPERIOR QUADTRANTONOPIA?
Lingual gyrus
Describe the optokinetic nystagmus in patients with occipital lobe infarcts?
NORMAL
Hemisensory loss + Hemianopia and NO PARALYSIS
Think of PCA territory
Lesion is within the PCA (before the thalamogeniculate branches to the lateral thalamus)
Lateral thalamus is infarcted and midbrain is spared. What is the presentation?
Hemisensory loss + hemiataxia, chorea and dystonic movements on the same side of hemisensory loss
ATAXIA- interruption of cerebellofugal fibers from SCP and RN that synapse in the VL of thalamus
CHOREA and DYSTONIA- interruption of extrapyramidal fibers from ansa leticularis to VL and VA thalamic nuclei
ALEXIA without AGRAPHIA
left PCA territory infarct
- Right occipital lobe can read the left hemi-space, but since the corpus callosum has been damaged, cannot be processed
Gerstmann Syndrome. Where is the lesion?
angular gyrus
R PCA infarction are accompanied by what symptom:
Prosopagnosia- difficulty in recognizing familiar faces
Syndrome wherein the patient may not recognize their visual deficit, and do not admit that they cannot see
Anton syndrome or visual anosognosia
How can a posterior circulation stroke present with behavioral change?
If hippocampus, fusiform, lingual gyri are infarcted, they can be confused with delirium tremens
Where data vs What data in occipital lobe processing?
Where data– goes to parietal and frontal regions
What data- middle and inferior temporal gyri, medial temporal limbic structures, amygdaloid nucleus hippocampus, ventrolateral frontal lobe cortex
If ventral pathway (lower banks of calcarine fissure) affected, major findings are:
prosopagnosia and defective color vision
If dorsal pathway is affected, what is the
