Chap 28 Morphology 2

Question 1

Morphology of acute meningitis

Answer 1

• Exudate is evident within the leptomeninges over the surface of the brain
• Meningeal vessels are engorged and prominent

Question 2

Where does H. influenzae meningitis usually occur?

Answer 2

Basal

Question 3

Where does pneumococcal meningitis usually located?

Answer 3

Over the cerebral convexities near the sagittal sinus

Question 4

What cell predominates the subarachnoid space in acute meningitis?

Answer 4

Neutrophils

Question 5

What occurs during fulminant meningitis?

Answer 5

Inflammatory cells infiltrate the walls of the leptomeningeal veins and can extend into the brain

Question 6

When does leptomeningeal fibrosis occur?

Answer 6

Following pyogenic meningitis and can cause hydrocephalus

Question 7

What is chronic adhesive arachnoiditis and when does it occur?

Answer 7

• Large quantities of polysaccharide of the organism produce gelatinous exudate that promotes arachnoid fibrosis
• Occurs mostly in pneumococcal meningitis

Question 8

What are abscesses?

Answer 8

• Discrete lesions with central liquefactive necrosis surrounded by brain swelling
• The outer margin of necrotic lesion has exuberant granulation tissue with neovascularization around the necrosis

Question 9

What are the characteristics of meningoencephalitis?

Answer 9

• Subarachnoid space contain gelatinous or fibrinous exudate

Question 10

Microscopic exam of diffuse meningoencephalitis

Answer 10

• Areas of mixed inflammatory infiltrates containing lymphocytes, plasma cells, and macrophages

Question 11

What is a tuberculoma?

Answer 11

Well-circumscribed intraparenchymal mass that may be associated with meningitis

Question 12

Appearance of a tuberculoma

Answer 12

• Central area of caseous necrosis surrounded by granulomas

Question 13

What is meningovascular neurosyphilis?

Answer 13

• Chronic meningitis involving the base of the brain, cerebral convexities, and spinal leptomeninges

Question 14

What causes paretic neurosyphilis?

Answer 14

• Invasion of the brain by T. pallidum

Question 15

What are the symptoms of paretic neurosyphilis?

Answer 15

• Progressive cognitive impairment (mood alterations)

- “General paresis of the insane” –> dementia

Question 16

Where is parenchymal damage in paretic neurosyphilis most common?

Answer 16

Frontal lobe

Question 17

What are the characteristics of the lesions for paretic neurosyphilis?

Answer 17

• Loss of neurons
• Proliferation of microglia
• Gliosis
• Iron deposits

Question 18

Why are there iron deposits in the lesions for paretic neurosyphilis?

Answer 18

From the small bleeds stemming from damage to the microcirculation

Question 19

How does Tabes Dorsalis occur?

Answer 19

Damage to the sensory axons in the dorsal roots

Question 20

What are the symptoms of Tabes Dorsalis?

Answer 20

• Impaired join position sense
• “Lightening pains”
• Locomotor ataxia
• Loss of pain sensation
• Charcot joints- skin and join damage
• Absence of deep tendon reflexes

Question 21

Microscopic examination of Tabes Dorsalis

Answer 21

• Loss of both axons and myelin in the dorsal roots

- Pallor and atrophy in dorsal columns in spinal cord

Question 22

Histology of encephalitides caused by arboviruses

Answer 22

• Perivascular accumulation of lymphocytes
• Multiple foci of necrosis of gray and white matter
• Neuronphagia
• Microglial nodules

Question 23

Neuronphagia

Answer 23

Single-cell neuronal necrosis with phagocytosis of debris

Question 24

Microglial Nodules

Answer 24

Microglial cells form small aggregates around foci of necrosis

Question 25

Where does HSV-1 encephalitis most severely involve?

Answer 25

Inferior and medial regions of the temporal lobes and orbital gyri of the frontal lobes

Question 26

What characteristics are present in HSV-1 encephalitis?

Answer 26

- Necrotizing and hemorrhagic regions - Perivascular inflammatory infiltrates - Cowdry type A intranuclear viral inclusion bodies

Question 27

What does CMV in immunosuppressed individuals cause?

Answer 27

Subacute encephalitis with are associated with CMV inclusion-bearing cells

Question 28

Where does CMV in immunosuppressed patients localize?

Answer 28

- Paraventricular subependymal regions of the brain | - Results in severe hemorrhagic necrotizing ventriculoencephalitis and a choroid plexitis

Question 29

Microscopy of CMV infection

Answer 29

Prominent enlarged cells with intranuclear and intracytoplasmic inclusions

Question 30

Appearance of acute cases of poliomyelitis

Answer 30

Show mononuclear cell perivascular cuffs and neuronophagia of anterior horn motor neurons of the spinal cord

Question 31

Brain examination of patient with Rabies

Answer 31

- Intense edema | - Vascular congestion

Question 32

Microscopic appearance of Rabies

Answer 32

- Widespread neuronal degeneration and inflammatory reaction most severe in the brainstem - Negri bodies

Question 33

What are Negri bodies?

Answer 33

- Found microscopically in Rabies | - Cytoplasmic, round/oval eosinophilic inclusions found in hippocampus and Purkinje cells

Question 34

What is HIV encephalitis?

Answer 34

Chronic inflammatory reaction associated with microglial nodules that contain multinucleared giant cells

Question 35

Where are microglial nodules found in HIV encephalitis?

Answer 35

Near small blood vessels which are prominent in endothelial cells and perivascular foamy or pigment laden macrophages

Question 36

What cells can HIV be detected in?

Answer 36

CD4+ mononuclear and multinucleated macrophages and microglia

Question 37

What occurs with cryptococcal infection?

Answer 37

Chronic meningitis affecting the basal leptomeninges which are thickened by connective tissue that can obstruct outflow of CSF causing hydrocephalus

Question 38

Where is CSF obstructed in cryptococcal infection from the connective tissue?

Answer 38

Foramina of Luschka and Magendie

Question 39

What are soap bubbles and where are they found?

Answer 39

- Found in subarachnoid space during cryptococcal infection, particularly the basal ganglia - Small cysts within the parenchyma

Question 40

What do the parenchymal lesions in cryptococcal infections consist of?

Answer 40

- Organisms within expanded perivascular spaces (Virchow-Robin)

Question 41

What occurs in Toxoplasmosis?

Answer 41

CNS brain abscesses mostly in cerebral cortex and deep gray nuclei

Question 42

Characteristics of acute lesions of toxoplasmosis

Answer 42

Central necrosis, petechial hemorrhages surrounded by acute and chronic inflammation, macrophage infiltration, and vascular proliferation

Question 43

What is the appearance of the lesions of toxoplasmosis after toxoplasmosis?

Answer 43

Large, well-demarcated areas of coagulative necrosis surrounded by lipid-laden macrophages

Question 44

What is the pathognomonic finding in classic CJD?

Answer 44

Spongiform transformation of the cerebral cortex and deep gray matter structures (caudate and putamen)

Question 45

Result of spongiform transformation in CJD

Answer 45

Small, empty microscopic vacuoles of varying sizes within the neuropil

Question 46

What are kuru plaques and where are they seen?

Answer 46

- Extracellular deposits of abnormal protein | - Seen in cerebellum with normal CJD and cerebral cortex for vCJD

Question 47

What is multiple sclerosis?

Answer 47

A white matter disease in the brain and spinal cord

Question 48

Appearance of MS lesions in the early state

Answer 48

Firm, surrounded by white matter (sclerosis) , well circumscribed, and appear depressed, glassy, with irregularly shaped plaques

Question 49

What are active plaques and when are they seen?

Answer 49

- Seen microscopically in MS on small veins | - Is ongoing myelin breakdown associated with macrophages

Question 50

What are inactive plaques and when are they seen?

Answer 50

- Microscopically in MS after lesions become quiescent - Have little to no myelin and a reduced number of oligodendrocyte nuclei - Astrocytic proliferation and gliosis are prominent

Question 51

What are shadow plaques and when are they seen?

Answer 51

- Microscopically in MS | - Have abnormally thinned out myelin sheaths