Pathology Exam 3

Front 1

Hypoxia/ischemic injury to the brain is characterized by what?

Back 1

Characterized by loss of ribonucleoproteins and denaturation of cytoskeletal proteins, resulting in cytoplasmic eosinophilia (red neurons), observed in hematoxylin and eosin stained sections

Front 2

How do astrocytes react to brain injury?

Back 2

React by producing a dense network of cytoplasmic processes surrounding the area of injury. This is somewhat analogous to a fibrous scar occurring elsewhere in the body, and is known as reactive gliosis

Front 3

These are major supporting cells of the brain

Back 3

Astrocytes

Front 4

Demyelinating disorders, such as MS, are caused by damage to what cells?

Back 4

Oligodendrocytes

Front 5

These are cuboidal cells that line the ventricles

Back 5

Ependymal

Front 6

Microglia

Back 6

- Derived from circulating monocytes
- Serve as APC in inflammatory conditions
- Act as scavengers during tissue necrosis

Front 7

Cells with large, foamy cytoplasm are called what?

Back 7

Glitter cells

Front 8

T/F Brain herniations are caused by intracranial pressure from low to high pressure compartments

Back 8

False, high to low

Front 9

These disorders cause increased intracranial imbalances (3)

Back 9

1) Cerebral edema
2) Brain herniations
3) Hydrocephalus

Front 10

Cerebral edema and its 2 types

Back 10

- Increase in water content within the brain parenchyma
- Types (vasogenic, cytotoxic)

Front 11

Herniation and 3 types

Back 11

- Brain swelling results in displacement of brain tissue from one intracranial compartment into another
- Types (transtentorial or uncal, cingulate and cerebellar tonsillar)

Front 12

Hydrocephalus

Back 12

Refers to accumulation of excess cerebrospinal fluid within the ventricular system of the brain. This can be caused by (i) decreased resorption of CSF (obstruction by a tumor or an inflammatory process) or rarely by (ii) by overproduction of CSF (tumors of the choroids plexus)

Front 13

Defined as rapidly evolving, non-epileptic, neurologic deficit that lasts > 24 hrs

Back 13

Stroke

Front 14

Circumscribed destructive lesions caused by local interruption of blood flow; account for about 70-80% of all cerebrovascular accidents. Atherosclerosis is the most common cause (predisposes thrombosis or embolism). 3rd most common cause of death in US.

Back 14

Infarct

Front 15

Risk factors for infarcts

Back 15

- Hypertension
- Smoking
- Diabetes
- Oral contraceptives

Front 16

These arteries are most commonly involved in infarcts

Back 16

Middle cerebral arteries

Front 17

Histology of infarct

Back 17

- Eosinophilic neurons and neutrophilic infiltration appear in 24-36 hours
- Macrophages begin to infiltrate by third day
- One month, softening and liquefaction result in an irregular cavity
- 6 months, a smooth walled cystic cavity

Front 18

Hypertension is the most common underling cause of this

Back 18

Intraparenchymal hemorrhage

Front 19

Intraparenchymal hemorrhage

Back 19

Accelerated atherosclerosis in larger and hyaline arteriolosclerosis in smaller vessels weaken the vessel walls with subsequent wall rupture and hemorrhage

Front 20

Most common regions of intraparenchymal hemorrhage

Back 20

Basal ganglia> pons> thalamus> cerebellum

Front 21

Subarachnoid hemorrhage

Back 21

Acute extravasation of blood in space between arachnoid and pia mater due to rupture of vessels in subarachnoid space. Often spontaneous (although traumatic injury may precipitate) and patients complain of “worst headache of my life”

Front 22

Ruptured berry (saccular) aneurysm (of major brain arteries) is most common cause of non-traumatic what?

Back 22

Subarachnoid hemorrhage

Front 23

Subarachnoid hemorrhage come from what vessels?

Back 23

From the branches of middle cerebral, internal carotid and the junction between the anterior cerebral and anterior communicating arteries

Front 24

T/F Intraparenchymal and subarachnoid hemorrhages cannot be seen together?

Back 24

False, they can

Front 25

Four major types of vascular malformations and how they result

Back 25

1) Arteriovenous
malformation (AVM)
2) Cavernous angioma
3) Capillary telangiectasias
4) Venous angioma
* Result from abnormal angiogenesis

Front 26

Vascular malformations

Back 26

They are composed of irregular collections of blood vessels of varying caliber that include arteries, veins and transitional forms. They can be associated with intraparenchymal as well as subarachnoid hemorrhage. Malformations can be an incidental finding, can cause focal neurologic deficits or can lead to fatal brain hemorrhage.

Front 27

__ are the most common vascular malformations and are most likely to give rise to brain hemorrhages

Back 27

Arteriovenous malformation (AVM)

Front 28

Leading cause of death and disability, accounting for over 25% of all accidental deaths

Back 28

Trauma
- blunt
- penetrating (gun shot)

Front 29

Traumatic injury involving blunt force include ____, ___ and ___

Back 29

Epidural hematoma, subdural hematoma and parenchymal injury.

Front 30

Epidural hematoma

Back 30

Arterial bleeding, frequently caused by rupture of a meningeal artery, usually as a result of skull fracture. Middle meningeal aretery is most commonly involved.

Front 31

Hematoma forms in between skull bone and dura matter, with compression of the underlying brain. Patients commonly experience a ‘lucid interval’, followed by progressive loss of consciousness.

Back 31

Epidural hematoma

Front 32

T/F Menigneal arteries are intimately attached w/ skull bones and are easily torn at fracture sites

Back 32

True

Front 33

Subdural hematoma

Back 33

Venous in origin. Caused by disruption of the bridging veins that extend from the surface of the brain to the dural sinuses. Blows to the head, vigorous shaking of head and whiplash injury may produce acute subdural hematoma

Front 34

Blood collects between dura matter and arachnoid membrane

Back 34

Subdural hematoma

Front 35

Chronic subdural hematomas are associated with what and how are they caused?

Back 35

Assoc. w/ atrophic brains (elderly) and may be caused by trivial trauma since atrophic brains have greater mobility w/i the cranium

Front 36

Traumatic parenchymal injuries include (3)

Back 36

1) Concussion
2) Contusion
3) Laceration

Front 37

Loss of consciousness with full recovery and no sequelae

Back 37

Concussion

Front 38

Contusion

Back 38

A hemorrhage in the superficial brain parenchyma caused by blunt trauma. Certain regions of the brain that come in contact with the skull are prone to develop contusioinal injury, including the frontal, temporal and occipital poles

Front 39

Coup lesion

Back 39

Contusion immediately underneath the point of contact

Front 40

Contrecoup lesion

Back 40

Contusion that develops in an area away from the site of impact

Front 41

Traumatic tearing of the superficial layers of brain

Back 41

Laceration

Front 42

Infectious routes

Back 42

Different routes of entry that include hematogenous spread, direct implantation (trauma), local extension of infections (sinusitis, middle ear or dental infections) and via peripheral nerves (rabies).

Front 43

___spread is the most common infectious route

Back 43

Hematogenous

Front 44

Acute Bacterial Meningitis

Back 44

Infections resulting in inflammation of the leptomeninges and subarachnoid space
- CSF involvement is a helpful diagnosis

Front 45

T/F Acute purulent meningitis is cause by pyogenic bacteria while chronic leptomeningitis is caused by both bacterial and fungal organisms

Back 45

True

Front 46

Extremes of age, crowded living conditions, poor hygiene, and debilitation are risk factors

Back 46

Acute bacterial meningitis

Front 47

Clinical features of bacterial meningitis

Back 47

Clinical features include fever, headache, stiff neck (due to meningeal irritation). Brain becomes swollen and congested. Purulence, necrotic debris and bacteria usually observed within meninges.

Front 48

Usually caused by bacteria including streptococci, staphylococci and anaerobic organisms. 50% are spread from adjacent infections (dental, ear or sinus infections). Streptococcus milleri is most commonly identified microorganism.

Back 48

Brain abscess

Front 49

Clinical manifestations of brain abscess and prognosis

Back 49

Usually solitary, can be multiple. Presents with headache, fever, neck rigidity, increased intracranial pressure and focal neurologic deficits. Extremes of age is a poor prognostic factor. Mortality is approximately 20%.

Front 50

Patient presents with headache, neck stiffness, pyrexia (fever) and focal seizures. Common morphological features include perivascular lymphocytosis, microglial nodules and neuronophagia. Sometimes, viral inclusions (eg. Cowdry A and Negri bodies) can be identified.

Back 50

Encephalitis

Front 51

Encephalitis

Back 51

Diffuse inflammation of brain parenchyma caused by a number of viral agents (HSV, HIV, cytomegalovirus and many arthropod-borne encephalitis viruses)

Front 52

Tumors of the brain arise from what?

Back 52

Cells of the brain or spinal cord and their coverings

Front 53

T/F Brain tumors present clinically by their site of origin rather than their pathologic type

Back 53

True

Front 54

T/F Tumor location has nothing to do w/ its behavior?

Back 54

False. Brain tumors have varying degrees of histological malignancy (for example the astrocytomas) but because of their critical location even benign tumors may behave in a “clinically malignant” fashion (i.e. result in fatality due to compression of vital structures)

Front 55

Second most common form of brain neoplasm

Back 55

Metastatic tumors (often from lung or breast)

Front 56

Most common adult brain tumor

Back 56

Astrocytoma
- WHO grade II, III, and IV

Front 57

Oligodendroglioma

Back 57

Cells with round nuclei and perinuclear halos. Slow growing (grade II)

Front 58

Ependymoma

Back 58

Intraventricular, slow growing (grade II). Cells make perivascular pseudorosettes.

Front 59

Meningioma

Back 59

Derived from the arachnoid matter. Forms cellular whorls and psammoma bodies. 2nd most common neoplasm.

Front 60

Usually cystic and occurs in the cerebellum, brain stem and optic nerve. Hairlike (piloid) processes, Rosenthal fibers and eosinophilic granular bodies are present.

Back 60

Pilocytic astrocytoma (grade 1)

Front 61

Located in the cerebellum. Cells form Homer-Wright rosettes. Usually disseminates through the CSF.

Back 61

Medulloblastoma (grade IV)

Front 62

T/F MS is more frequent in equatorial regions

Back 62

False, temperate

Front 63

Typically present in young adults, with waxing and waning of signs and symptoms, depending on the regions of brain involvement. Common manifestations include visual disturbances, speech and gait abnormalities, paresthesias and emotional disturbances

Back 63

MS

Front 64

Common site of MS plaques

Back 64

Perivascular white matter, optic nerve, etc., but can occur anywhere in the brain or SC

Front 65

Histology of MS plaques

Back 65

Microscopically, plaques are characterized by areas of demyelination, accompanied by variable presence of perivascular lymphocytosis and infiltration by foamy macrophages

Front 66

Neurodegenerative diseases can be ___ or ___, can have variable signs and symptoms including ___, movement disorders, ___, and ___

Back 66

Sporadic, familial, dementia, tremor, rigidity

Front 67

Alzheimer's Disease

Back 67

- Most common cause of elderly dementia
- Mostly sporadic, 10% familial
- Atrophic brain (loss of vol. & weight) and dilation of ventricular system
- Patients present w/ progressive loss of memory and other cognitive functions that are non-reversible

Front 68

Diagnostic features of of Alzheimers

Back 68

1) Senile or neuritic plaques
- aggregates of thickened, tortuous processes with a central amyloid core
2) Neurofibrillary tangles
- coarse, filamentous aggregates within the cytoplasm of the neurons

Front 69

The hallmark of Parkinson's disease

Back 69

Intracytoplasmic inclusion bodies known as Lewy bodies, within the pigmented neurons of the substantia nigra and locus ceruleus

Front 70

The substantial nigra and locus ceruleus are involved in what disease?

Back 70

Parkinson's

Front 71

Parkinson's Disease

Back 71

- This is caused by degeneration of the dopamine secreting pigmented neurons of the substantia nigra in the midbrain
- Unknown etiology
- Most are sporadic cases in 6th decade
- Mildly atrophic brain

Front 72

Hereditary and progressive disorder characterized by spontaneous involuntary movements called chorea and also dementia.

Back 72

Huntington's Disease

Front 73

Hallmark of Huntington's disease

Back 73

The atrophy of the basal ganglia (caudate, putamen and sometimes globus pallidus)

Front 74

Huntington's Disease

Back 74

The onset is usually in the 4th or 5th decade. The disease is caused by mutations in the huntingtin gene, located in the short arm of chromosome 4. Microscopically, there is severe neuronal loss in the basal ganglia, accompanied by fibrillary gliosis.