CNS pathology- 2 Flashcards
What are astrocytomas?
glial neoplasms derived from astrocytes
75-80% of adult primary brain tumors
usually middle age or older
Where are Astrocytomas usually found?
Adults- in the cerebral hemispheres
Peds- Cerebellum and the pons
Grade I Astrocytoma
20% of primary intracranial neoplasms
- poorly demarcated
- infiltrates the cortex
- indistinct margin
- can also be seen in the pons/cerebellum in peds and cervical spinal cord in young adults
What is the life expectancy for a Grade I Astrocytoma?
~5 years
How do you distinguish Anaplastic (Grade II) Astrocytoma from a well-differentiated astrocytoma?
- Greater cellularity
- Cellular pleomorphism
- Anaplasia
*distribution parallels that of Grade I
What is the growth and life expectancy of an Anaplastic (Grade II) Astrocytoma?
growth is rapid
life expectancy= ~3yrs
Glioblastoma Multiforme (GBM)–> AKA grade III astrocytoma
- 40% of primary intracranial neoplasms
- life expectancy= 18mo
- Infiltrates extensively into cortex, often crossing the corpus callosum w/ bilateral extension into the white matter of both hemispheres
What is seen on gross examination of Glioblastoma Multiforme (GBM)?
-Both bottled red (recent hemorrhage) and yellow (remote hemorrhage) likened to a butterfly on gross examination
What differentiated oligodendrogliomas from other tumors?
- well-circumscribed, gelatinous, grey masses, often with cysts, focal hemorrhage and calcification
- Slow growth is reflected by absence of mitotic figures and necrosis (so better prognosis than astrocytomas)
- common complaint: seizures
What is the most common presentation of Epenymomas?
-hydrocephalus secondary to progressive obstruction of the 4th ventricle (whee they are commonly located) x
What chromosomal aberration is seen in meningiomas?
Majority arise sporadically and exhibit either a deletion or mutation of chromosome 22
What is the characteristic cell that is seen in Parkinsons disease?
Lewy Bodies
What is the number 1 etiology as to why Hypertensive bleeds occur that are related to HTN?
- Charcot-Bouchard aneurysms (formed from the weakening of the walls of cerebral arterioles) are predisposed to rupture and cause hypertensive cerebral rupture
- Have a graphic distribution
What is the number one etiology of why strokes occur?
Artherosclerosis- predisposes to vascular thrombosis and embolic events –> both result in ischemia and subsequent cerebral infarction
What is are meningiomas?
- intracranial tumors that arise from the arachnoid villi and produce sxs by compressing brain tissue.
- 20% of intracranial tumors
What is the peak incidence of meningiomas?
4th-5th decades
Slightly more common in females (60:40)
Where are meningiomas most commonly located?
In the parasagittal areas, convexities of the cerebral hemispheres, the olfactory groove and the lateral wing of the sphenoid
What do meningiomas have a propensity to do?
erode contiguous bone
Other than chromosomal abberations, what else can cause meningiomas?
Cranial radiation (related to dosage)
How do meningiomas appear grossly
well-circumscribed, firm, bosselated masses of variable size
-cut sections show a gray, fibrous patter
What is the clincial presentation of meningiomas?
depending on location, seizures rather than neuro deficits characterize the pt (due to lesions positioned in the parasagittal and over the convexities of the hemispheres)
Clinical presentation of meningiomas
tumors in the olfactory groove produce ansomnia
Tumors in suprasellar region- visual defects
HA’s common
What is Kernig sign?
Pain in the knee when the hip is flexed
–> sign of bacterial meningitis
What is the Brudzinski Sign?
Spontaneous flexion of the knees and hips when the neck is flexed
–> sign of bacterial meningitis
What are two special physical exam tests you can perform on a patient to test for bacterial meningitis?
Kernig and Brudzinski signs
+= bacterial meningitis
What is an Acoustic Neuroma?
- Intracranial Schwannoma that is restricted to CN8
- Malignancy is rare
Symptoms of Acoustic Neuroma
- tinnitus
- Deafness
Can also compress other Cranial nerves
Where are Acoustic Neuromas usually found?
- Found in the cerebellar pontine angle
- restricted to CN8
What is Multiple Sclerosis?
A chronic, demyelinating dz of the CNS which there are numerous patches of demyelination throughout the white matter
- Affects both sensory and motor functions
- Characterized by exacerbations and remissions over several yrs
What is the prevalence of MS?
Most common demyelinating disorder
1 in 1000
What is the etiology of MS?
unknown
experimental studies point to possible genetic, immune and infectious etiology
What are early symptoms of MS? What is often the presenting complaint?
- blurred vison or unilateral vision loss
- double vision
- vertigo
Who is most likely to get MS?
- Usually occurs in temperate climates (rare in tropics)
- Acquired at mean age of 30. Rare <14y/o and >60
- Women afflicted 2x more than men
Genetic factors associated with MS
suggest a familial aggregation of the dz w/ an increased risk in 2nd and 3rd degree relatives
What are immune factors related to MS?
Immune factors are related to the histologic appearance of lesions: perivascular lymphocytes and macrophages with numerous CD4+ and CD8+ T-cells
What viruses are associated with MS?
measles
mumps
rubella
herpes
*no direct evidence exists for this involvement
What is the hallmark of MS?
the plaque
-variable in sz w/ smooth rounded contour
Where is the plaque, that is a hallmark of MS, located?
Usually situated in the white matter
occasionally breech the gray-white junction
- shows a preference for optic nerves and chiasm and uniformly localizes to the periventricular white matter
- Can also involv the cerebellum brainstem and SC (but mainly around the ventricles)
What happens as the plaque in MS ages?
- it becomes more discrete and the edema regresses
- Astrocytes traverse the aging plaque and the tissue becomes dense with glial processes
What symptoms are seen in a patient with MS if the plaques are within the spinal cord?
- weakness of one or both legs
- numbness in the lower extremities
Are the initial sxs of MS reversible?
many of the initial sxs are partially reversible w/in a few months
What is the degree of functional impairment in MS?
variable.
Ranges from minor disability–> sever incapacity with widespread paralysis, dysarthria, severe visual defects, incontinence and dimentia
How do patients with MS usually die?
usually die of respiratory paralysis or UTIs in terminal coma
What is the prognosis of MS?
Most patients survive 20-30 years after onset of sxs
