CNS Trauma Flashcards
Penumbra
Region between necrosis and normal brain tissue that is “at risk”
Neurons that are most sensitive to ischemia and hypoglycemia
Large pyramidal neurons
Hippocampus- Sommer Sector
Purkinje cells of the cerebellum
Morphology of global cerebral ischemia
Brain is swollen
Gyri are widened
Sulci are narrowed
Poor demarcation between gray and white matter
Stages of global cerebral ischemia
Early- red neurons
Subacute- liquefactive necrosis, influx of macrophages
Repair- gliosis
Pseudolaminar necrosis- uneven destruction/preservation of cortex
Border zone infarcts (watershed)
Wedge shapes
Most distant field of arterial perfusion
Between anterior and middle cerebral arteries at greatest risk
Areas that don’t have collateral blood flow
Thalamus
Basal ganglia
Deep white matter
Atherosclerosis (thrombosis)
Carotid bifurcation, origin of middle cerebral artery, ends of basilar artery
Often associated with HTN and DM
Arteritis (thrombosis)
Infectious vasculitis (immunosuppressed and opportunistic infection)
Origins of embolism
Cardiac mural thrombi
Atheromatous plaque of carotid artery
Paradoxical embolus
Surgery
Area most often affected by embolus
Middle cerebral artery
Morphology of non hemorrhagic focal cerebral ischemia
48hrs- pale, soft, edematous
2 to 10 days- boundary of infarct more distinct
10 d to 3 wks- liquefactive necrosis, gliosis, cavity
Hypertensive Cerebrovascular disease: Lacunar infarcts
Affects deep penetrating arteries and arterioles- basal ganglia
Cause: arteriosclerosis
Occur in lenticular nucleus, thalamus, internal capsule, deep white matter
Hypertensive Cerebrovascular disease: slit hemorrhage’s
Small hemorrhages that are resorbed
Hypertensive encephalopathy Acute
HA, confusion, vomiting, convulsions, coma
Treat urgently to avoid increase ICP
Hypertensive encephalopathy occurring over months
Multiple infarcts bilaterally in gray and white matter results in syndrome of dementia, gait abnormalities, pseudobulbar signs and neurologic deficits
Caused by multifocal vascular disease
Multifocal vascular disease
Cerebral atherosclerosis
Vessel thrombosis or embolism
Cerebral arteriolosclerosis from chronic hypertension
Binswanger disease
Multifocal vascular disease that predominantly involves white matter
Intracerebral Hemorrhage
Peak at 60 yo
Caused by hypertension:
Accelerated atherosclerosis (large vessel)
Hyaline arteriolosclerosis (small vessel)
Weaker vessel allows aneurysms to form- commonly in basal gangli
Rupture of intraparenchymal vessel
Putamen
Lobar hemorrhage
Hemorrhage into loves of cerebral hemisphere
Most common cause is cerebral amyloid angiopathy (CAA)
Subarachnoid hemorrhage
Rupture of saccular aneurysm
90% in anterior circulation
Increased risk with AD polycystic kidney disease, Ehlers-Danlos, neurofibromatosis type I️, Marfan
Morphology of saccular aneurysms
Thin walled outpouching
Muscular vessel wall and internal elastic laminate are not in the wall of the aneurysm
Wall of aneurysm has thickened, hyalinized intima covered by adventitia
Usually ruptures at apex
Clinical of subarachnoid hemorrhage
Acutely: vasospasm from irritation of vessels by blood
Can occur in other vessels
May cause additional ischemic injury
Late sequelae:
Meningeal fibrosis and scarring
Obstruction to CSF flow and reabsorption
Arteriovenous malformations
Detected at 10-30 yo
Seizure
Intracerebral hemorrhage
Subarachnoid hemorrhage
Middle cerebral artery most common site
Tangled vessels, pulsatile
Basilar skull fracture
At least one of the following:
Cribiform plate Orbital plate Temporal bone- petrous and squamous portions Sphenoid bone Occipital bone
