Brain masses, lesions, and other on imaging Flashcards
large solitary tumor within cerebral hemisphere with irregular enhancing margins and central necrotic core
glioblastoma multiforme tends to spread across the corpus callosum
multiple lesions at the junction of gray and white matter with surrounding edema
non seminomatous germ cell tumors
Rarely metastasize to brain but when they do they show up as mentioned
what is seen on imaging with cerebral toxoplasmosis
ring enhancing lesions on neuroimaging. Rarely seen in immunocompetent pts Seen in HIV pts
HIV pt with headache confusion and fever. Check for what?
cerebral toxoplasmosis
CNS TB presents with
subacute febrile illness followed by meningismus, focal deficits, confusion, and seizure
CNS TB on imaging
basilar meningeal enhancement hydrocephalus, tuberculomas (iso hyperdense encapsulated lesions with ring ehancement)
Mexican immigrant presents with seizure. think about
neurocysticerocosis
Multiple viable cysts 5-20 mm hypodense lesions in brain parenchyma
neurocysticerocosis
Name the condition
glioblastoma multiforme.
from glial cells and it grows so fast there are no calcifications.
seizure or focal weakness, headache worse on coughing or lying down.
34 y o woman with acute headache then generalized tonic clonic seizures. Felt fine until 6 hrs ago when she developed a 10/10 throbbing bilateral headache and blurry vision. She is mulitple HTN meds and never had a history of seizure.
Temp normal, BP 210/140 and HR 80 and neuroexam: awake and alert but oriented to person and place. See copper and silver wiring no papilledema on fundoscopic exam. CT shows loss of greay white matter differentiation in posterior occipital parietal lobes and this is the MRI. What does she have?
PRES - posterior reversible encephalopathy syndrome
AKA
reversible posterior leukoencephalopathy syndrome (RPLS)
what causes PRES?
often seen with hypertensive crisis,
chemotherapy agents (cyclosporine)
eclampsia, preeclampsia,
allogenic bone marrow transplant
medical renal dx,
autoimmune dx,
sepsis and shock.
what is posterior leukoencephalopathy syndrome?
PRES
also called hyperperfusion encephalopathy
brain capillary leak syndrome
What is the pathophysiology behind PRES or brain capillary leak syndrome?
brain edema likely from diminished sympathetic innervation of the posterior circulation.
posterior regions of the brain are more susceptible to injury from high mean arterial pressures, which MAP increased in brain parenchyma and subseqent vasogenic edema
which areas of the brain are most susceptible to PRES?
parietal and occipital lobes, then the frontal lobes and inferior temporal occipital junction and cerebellum
rare case reports of brainstem and cervical cords.
Treatment of PRES:
lowering BP - no more than 25% in first 6 hrs
stop any precipitating drugs
antiepileptic therapy for seizures
most pts are experience reversal in symptoms within 2 weeks.
Must also need to get imaging. MRI imaging to rule out stroke or ICP
what is this CT scan show?
subarachnoid hemorrhage and this is a medical emergency. need to get aniogram to do coiling or embolization
Can be seen with fibromuscular dysplasia or twisting of arteries (see spontaneous coronary artery dissection or renal FMD)
25% mortality rate in 1st 24 hrs of presentation to hospital due to rebleeding.
what is on this CT scan of the head?
subarachnoid hemorrhage.
look for acute blood products or white contrast in the cisterns on neuroimaging.
Herpes simplex virus encephalitis you see:
high signal flaire abnormality with enhancement in bilateral or unilateral temporal lobes
see fever, headache, change in mental status and seizures.
what is seen in idiopathic intracranial hypertension
young obese women with recurrent postural headaches (worse in supine position) and visual obscurations, papilledema, and rarely visual loss
no changes on brain MRI.
what does this image show?
Pt had MVA, new onset headache which radiates to left side of neck. Also has global aphasia, right homonymous hemianopsia, left pupillary miosis and partial ptosis and left gaze preference
Reduced sensation on right side of face and body and right sided hemiparesis and extensor response at the right big toe on plantar cutnaeous stimulation.
Has traumatic left internal carotid artery dissection causing ipsilateral MCA stroke and ipsilateral horners syndrome. carotid dissection can present as transient vision loss, ischemic stroke or embolic stroke
Because the post ganglionic sympathic fibers run on outside surface of ICA to supply the head, ICA dissection can damage fibers and lead to partial ipsilateral Horner’s (partial ptosis, miosis without anhidrosis).
See MRA/CTA with a ICA with t_apered, flame-shaped apperance rather than blunt stumped appearance_ of vascular occlusion.
how are cervical neck artery dissections treated?
many are treated with aspirin and not anticoagulation
If there’s any concern for brain herniation what to do next?
IV dexamethasone to prevent brain herniation. Dexamethasone is preferred because lacks mineralcorticoid effects.
may see Cushing’s triad: high BP and irregular respirations and bradycardia - sign of ICP
what to do for ICP?
while waiting for definitive treatment options, some other thing should be
ELEVATION of hehad of bed to 30 degrees,
artificial respiratory alkalosis with lower ICPs
also need emergent intubation-even if there’s no respiratory compromise
give glucocorticoids
needs CT head to confirm herniation to look for a cause (stroke, tumor, hemorrhage)
second most frequent cause of thunderclap headache is:
reversible cerebral vasoconstriction syndrome - recurrent thunderclap headache. See multifocal constriction of intracranial vessels normalizing within 3 months of onset.
Triggered: exertion, valsalva maneuver, emotion, and bathing
Presentation: focal deficits, encephalopathy and seizures
Need to get a MRA/CTA and CSF analysis to rule out stroke and infection.
Brain MRI may show areas of white matter edema in occipital or parietal lobe compatible with posterior reversible encephalopathy syndrome. see a_reas of ischemia and hemorrhage in parenchyma and sub dural or subarachnoid hemorrhage_
