Causes of Seizures 1/16

Question 1

Types of brain herniation

Answer 1

Question 2

Subfalcine herniation

Answer 2

may compress ant. cerebral art.

Question 3

transtentorial herniation

Answer 3

may compress:

1) CNIII= see ipsilateral dilated pupil and impaired eye movement
2) post. cerebral art.= primary visual cortex
3) cerebral peduncle=kernohan’s notch, ipsilateral hemiparesis
4) pons and midbrain= duret hemorrhage due to vessel tearing–>life threatening

Question 4

tonsillar herniation

Answer 4

brain stem compression–>cardiac and respiratory centers

Question 5

NO LP if CT shows:

Answer 5

mid-line shift, loss of CSF cisterns, post. fossa mass–>high risk of herniation

Question 6

CT without contrast

Answer 6

hemorrhage/hematoma, skull fx/trauma, hydrocephalus, fluid accumulation/abscess

Question 7

CT with contrast

Answer 7

tumor(angiogenesis), vascular malformation, infection/inflammation

Question 8

intracranial hemorrhage

Answer 8

related to HTN and peak age is 60. most frequent sites: thalamus, basal ganglia, pons and cerebellum

Question 9

Charcot-bouchard micro aneurysms

Answer 9

associated with chronis HTN. Minute aneurysms in small vessels which can rupture

Question 10

subarachnoid hemorrhage

Answer 10

caused by bleeding from cerebral arterial aneurysms. bleeding is at arterial pressure. “The worst headache of my life” then loss of consciousness. re-bleeding is common among survivors.

Acute: vasospasm–>ischemia

chronic: meningeal fibrosis–>hydrocephalus

Question 11

berry aneurysm

Answer 11

bright red, shiny surface and a thin, translucent wall. often arise at junctions of vessels due to defect in vessel walls at branch points.

cerebral vessels have only one elastic lamina(internal elastic lamina)–>more prone to dilation

Question 12

picture of berry aneurysm development

Answer 12

Question 13

atherosclerotic aneurysm

Answer 13

arises as dilation of entire part of an artery weakend by atherosclerosis. less common than berry.

Question 14

mycotic aneurysm

Answer 14

arises in vessel walls weakend by microbial infx, usually bacteria, despite the name.

Question 15

epidural hematoma

Answer 15

due to rupture of middle meningeal art. due to traumatic skull fx–>seperation of dura from inner surface of skull–> compression of brain.

pts lucid for several hours then develop neurological signs. emergency drainage required

Question 16

picture of epi and subdural hematomas

Answer 16

Question 17

subdural hematoma

Answer 17

bridging veins from cortical convexities to sup. sagittal sinus travel through the space between dura and arachnoid layer (subdural).

elderly with cerebral atrophy are at risk due to stretching of veins. Infants are also at rick because veins are thin-walled and fragile

Question 18

signs and symptoms of chronic subdural hematoma

Answer 18

headache, confusion and focal signs

Question 19

CSF production

Answer 19

by choroid plexus in lateral and 4th ventricles–>enters subarachnoid space at cisterna magna through foramina of luschka and magendie.

CSF reabsorbed through arachnoid granulations of sup. sagittal sinus.

Question 20

hydrocephalus

Answer 20

obstruction, overproduction, loss of cerebral tissue.

if before closure of cranial sutures–>increased head circumference

after–>increased ICP

Question 21

non-communicating hydrocephalus

Answer 21

obstruction within ventricular system: mass lesions, aqueductal stenosis, obstruction of 4th ventricle

Question 22

communicating hydrocephalus

Answer 22

obstruction outside the ventricular system: subarachnoid hemorrhage or meningitis with secondary meningeal scarring

Question 23

hydrocephalus ex vacuo

Answer 23

if there is less brain tissue–>compensatory enlargement of ventricles (alzheimer’s)

Question 24

choroid plexus papilloma

Answer 24

results in csf overproduction

Question 25

Preference of location of brain abscesses

Answer 25

frontal lobe>parietal>cerebellum

Question 26

clinical findings of brain abscess

Answer 26

progressive focal deficits, increased csf, white cells and protein, normal glucose

Question 27

arterio-venous malformations AVM

Answer 27

largest intracerebral malformations, tangled network of wormlike vascular channels, prominent pulsatile arterio-venous shunt with high blood flow through the malformation.

tend to occur in cerebral hemispheres

Question 28

cavernous hemangioma

Answer 28

greatly distended, loosly organized vascular channels with thin, collagenized walls

Question 29

capillary hemangioma

Answer 29

rarely cause symptoms during life

Question 30

tuberculous meningoencephalitis

Answer 30

csf: moderate lymph or lymph+poly, protein elevated, glucose moderately reduced or normal

arteries in subarachnoid space may show obliterative endarteritis (heubner’s arteritis)

pus usually accumulates at base of brain

Question 31

Brain tumors in adults

Answer 31

supratentorial. Gliomas are most common primary tumors>meningioma

Question 32

brain tumors in chidren

Answer 32

secondary to hematopoietic tumors. Infratentorial. most are astrocytoma>medulloblastoma>ependymoma

Question 33

infratentorial tumors

Answer 33

adults: schwannomas>gliomas of brain stem> mets
children: astrocytoma>medulloblastoma>ependymomas

Question 34

extradural tumors of spine

Answer 34

usually within vertebral body. most common in adult: mets>primary tumors of bone

Question 35

intradural tumors of spine

Answer 35

between dura and spinal cord or within spinal cord=intramedullary

meningioma>ependymoma>astrocytoma

Question 36

astrocytoma high grade=glioblastoma multiforme=anaplastic astrocytoma

Answer 36

increased number of astrocytes that are anaplastic, necrosis with pseudopallisading of tumor cells. poor prognosis–>cerebral edema+herniation

Question 37

pilocytic astrocytoma

Answer 37

usually in cerebellum, but also optic nerve and 3rd ventricle. usually benign but 3rd ventricle pilocytic astrocytoma has poor prognosis

Question 38

oligodendroglioma

Answer 38

fried egg appearance, well-circmscribed, can be cystic with calcification

Question 39

ependymoma

Answer 39

tumor of 4th ventricle–>hydrocephalus, in young children

Can occur in spinal cord in middle life. See ependymoma rosettes

Question 40

medulloblastoma=pnet=peripheral neuroectodermal tumor

Answer 40

usually found in cerebellar vermis and can spread down the spinal cord=drop mets. See small cells with prominent nucleoli, scant cytoplasm and occasional rosettes

Question 41

meningioma

Answer 41

benign, from subarachnoid cell, see whorls with psammoma bodies, compresses the brain

Question 42

primary CNS lymphoma

Answer 42

from microglia, associated with AIDS and renal transplant, mostly B cell phenotype, diffuse infiltration of brain tissue, micro:see large cell lymphoma, poor prognosis

Lesions are often multiple in gray and white matter

Question 43

mets to brain

Answer 43

often multiple, well-circumscribed and at white-gray junction. Often come from lung, breast, kidney

Question 44

carcinomatous meningitis

Answer 44

tumor deposits throughout CNS in subarachnoid space–>widespread neurological dysfunction.

Seen most often with adenocarcinomas, including carcinomas from breast or stomach

Question 45

schwannoma

Answer 45

acoustic neuroma, CNVIII, Antoni A and B, verocay bodies (pallisading of nuclei), thickend vessels

Question 46

Neurofibroma

Answer 46

NF 1 mutation, fusiform noncircumscribed enlargement of nerve seen often at distal part of nerve. micro: see interlacing bands of spindle cells wih elongated nuclei. Hard to remove from nerve. Can infiltrate adjacent tissue.