Neuro: Leech - Cns Infections

Front 1

Special Considerations......

Back 1

Cranium
No lymphatic system
Unique circulation
Limited immunologic surveillance
Blood-brain barrier
Watershed area

More General Thoughts:
Age of the pt
Immune status of pt
Time of yr

Front 2

What is Meningitis?

Inflammation of leptomeninges
There is:
1. acute
2. subacute
3. chronic

Back 2

What is Encephalitis?

Front 3

Inflammation of the brain regions

there is:
1. Diffuse
2. Locatized

Back 3

What is a CNS abscess?

Infectious mass withing the parenchyma.

central necrosis and capsule formations

Front 4

What are the main ways that pathogens can enter the CNS?

Back 4

1. Hematogenous spread
2. Direct Impantation
3. Local Extention
4. Peripheral Nervous System

Front 5

example of hematogenous spread?

Back 5

Arterial and venous spread

Front 6

example of direct implantation spread?

Back 6

almost always traumatic

Front 7

Example of local extension

Back 7

Air sinus (mastoid, frontal) or tooth

Front 8

Example of peripheral nervous system?

Back 8

Certain viruses......
rabies
herpes zoster

Front 9

There are 5 basic categories of infections we are going to learn:

Back 9

1. Acute bacterial or viral infections that involve leptomeninges and CSF

2. Acute bacterial infections of subdural spaces or CNS parenchyma

3. Chronic bacterial infections of the brain and meninges

4. Acute, subacute or chronic viral infection of the brain

5. Fungal and parasitic infections

Front 10

There are different CSF lab findings for different forms of meningitis......

Back 10

Given the lab values tell me the type of Meningitis.

Front 11

<5 lymphocytes
Glucose 45-85
Proteins 15-45
Pressure 70-180

Back 11

Normal CSF

know we are looking at cerebral spinal fluid (CSF) to Dx meningitis

Front 12

Up to 90,000 Neutrophils
glucose is decreased <45
proteins are increased >50
Pressure is markedly elevated

Back 12

Purulent
Bacterial

Front 13

100-1,000 most lymphocytes
glucose is nl
proteins are increased >50
pressure is slightly elevated

Back 13

Aspectic
Viral

Front 14

100-1,000 most lymphocytes
glucose is decreased <45
proteins are increased >50
Pressure is Moderately elevated

Back 14

Granulomatous
mycobacterial
fungal

Front 15

What is the most common cause of acute meningitis*** in the given population?

Neonates

Back 15

e. coli

group B strep

Front 16

What is the most common cause of acute meningitis*** in the given population?

Infants and young children

Back 16

H. influenza

but decreased bc of immunizations

Front 17

What is the most common cause of acute meningitis*** in the given population?

Adolescents and young adults

Back 17

Neisseria meningitidis

Front 18

What is the most common cause of acute meningitis*** in the given population?

Elderly

Back 18

Strep pneumo

Listeria monocytogenes

Front 19

What is the most common cause of acute meningitis*** in the given population?

Viral causes.....

Back 19

enteroviruses
(echo, coxsackie, polio)

Front 20

What are the clinical signs of Acute Meningitis?

Back 20

Headache, fever, nuchal rigidity, cloudy sensorium, coma, death

Viral is self-limited and has low mortality

Front 21

What are the Gross findings of acute meningitis - Bacterial***

Back 21

Purulent leptomeningeal inflammation, cloudy CSF, vascular engorgement, may extend to cortex

Front 22

What are the Gross findings of acute meningitis - Viral***

Back 22

Mild leptomeningeal inflammation, brain swelling

Front 23

What are the microscopic findings of acute meningitis?

Bacterial***

Back 23

PMN’s fill subarachnoid space; Gram-stain shows organism; vessels are involved by PMN’s

Front 24

What are the microscopic findings of acute meningitis?

Viral***

Back 24

Very little except lymphocyte infiltrate of leptomeninges

Front 25

What the heck is Leptomeninges?

Back 25

In medicine, leptomeninges (literally thin meninges) is a term used to refer to the pia mater and arachnoid mater, two of the membranes that surround the brain and the spinal cord

Front 26

What is the sequelae of bacterial acute meningitis?

Back 26

Hydrocephalus, leptomeningeal fibrosis (may cause cranial nerve impairment)

Front 27

What is the sequelae of viral acute meningitis?

Back 27

Very little, if any

Front 28

What the heck does sequelae mean?

Back 28

a pathological condition resulting from a disease, injury, or other trauma.

Front 29

What may be seen on the meninges from acute meningitis?

Back 29

The yellow-tan clouding of the meninges seen here is due to an exudate from acute meningitis

Front 30

What are clinical signs of meningitis?

Back 30

Clinical signs may include:
headache, neck stiffness (from irritation of spinal nerve roots), fever, and clouded consciousness.

Front 31

Here is another example of an acute meningitis from bacterial infection

Back 31

The cerebrospinal fluid (CSF) in such cases typically has a low glucose, high protein, and many PMN's. A gram stain should be done to identify organisms.

Front 32

Picture time

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Microscopically, a neutrophilic exudate is seen involving the meninges at the left, with prominent dilated vessels. There is edema and focal inflammation (extending down via the Virchow-Robin space) in the cortex to the right.

This edema can lead to herniation and death. Resolution of infection may be followed by adhesive arachnoiditis with obliteration of subarachnoid space leading to obstructive hydrocephalus.***

This acute meningitis is typical for bacterial infection.*****

Front 33

picture

Back 33

A gram stain reveals gram negative diplococci within a neutrophil, typical for Neisseria meningitidis.

Front 34

Acute Focal Suppurative Infections Clinical Signs

Back 34

Predisposing conditions:

Acute bacterial endocarditis, right to left shunts, chronic pulmonary sepsis
Mastoiditis, paranasal sinusitis, acute otitis, open fracture, previous neurosurgery


Might also see:
Signs of increased intracranial pressure; focal neurologic deficits

Front 35

What are the gross findings of Acute focal suppurative infections?

Back 35

CT/MRI; ring-enhancing lesion

Central region of liquefactive necrosis with fibrous capsule (often marked cerebral edema)

Front 36

What are the micro findings of acute focal suppurative infections?

Back 36

Granulation tissue, collagen capsule, zone of reactive gliosis

Front 37

What is the Sequelae of acute focal suppurative infections?

Back 37

Increased intracranial pressure and progressive herniation can be fatal

Rupture of abscess can cause ventriculitis, meningitis, venous sinus thrombosis

Surgery and antibiotic therapy can reduce mortality to less than 10%

Front 38

Acute brain swelling in the closed cranial cavity is serious

Back 38

Swelling of the left cerebral hemisphere has produced a shift with herniation of the uncus of the hippocampus through the tentorium, leading to the groove seen at the white arrow.

Front 39

next picture

Back 39

Acute cerebral swelling can also often produce herniation of the cerebelllar tonsils into the foramen magnum. Note the cone shape of the tonsils around the medulla in this cerebellum.

Front 40

Next Picture

Back 40

The end result of herniation is compression and Duret hemorrhages, as seen here in the pons.

Front 41

What can cause abscesses in the brain?

Back 41

This is a cerebral abscess. There is a liquefactive center with yellow pus surrounded by a thin wall. Abscesses usually result from hematogenous spread of bacterial infection, but may also occur from direct penetrating trauma or extension from adjacent infection in sinuses.

Front 42

This computed tomographic (CT) scan of the head in transverse view demonstrates What????

Back 42

This computed tomographic (CT) scan of the head in transverse view demonstrates an abscess in the brain in a patient who had septicemia.

Front 43

What kind of stain is used to analyze cerebral abscess?


EXAM****

Back 43

This trichrome stain demonstrates the light blue connective tissue in the wall of an organizing cerebral abscess.

Normal brain is at the right and the center of the abscess at the left.

Front 44

What is this a picture of?

Back 44

This magnetic resonance imaging (MRI) scan of the head in transverse (axial) view demonstrates a small abscess in the brain in a patient who had septicemia.

Front 45

what is marked dilation of the cerebral ventricles?

Back 45

Hydocephalus

Front 46

What can cause Hydrocephalus?

Back 46

Hydrocephalus can be due to lack of absorption of CSF or due to an obstruction to flow of CSF.

Front 47

What are 3 causes of Chronic Bacterial meningocephalitis?

Back 47

Tuberculosis (mycobacterium tuberculosis)

Neurosyphilis (treponema pallidum)

Lyme Disease (borrelia burgdorferi)

Front 48

What is this?


Gross – fibrinous exudate at base of brain and encasing cranial nerves, white granules scattered over the leptomeninges

Back 48

Tuberculosis

Front 49

What is this?

Micro – mononuclear cell mixture; may see granulomas, may see an intraparenchymal mass (tuberculoma)

Back 49

Tuberculosis

Front 50

What is the clinical symptoms of Tb?

Back 50

Clinical – headache, malaise, mental confusion, vomiting

Front 51

What is this?

Gross – mononuclear meningitis involving base of brain and frontal lobe cortex

Back 51

Neurosyphilis

Front 52

What does this explain?

Micro – perivascular inflammatory infiltrate of plasma cells and lymphocytes; may see gummas

Back 52

Neurosyphilis

Front 53

What are the clinical signs of Neurosyphilis?

Back 53

Clinical – insidious, progressive loss of mental and physical functions, mood changes, terminating in dementia; tabes dorsalis results from damage to dorsal roots

Front 54

What does this describe?

Gross – variable, meningitis

Back 54

Lyme Disease

Front 55

What does this describe?

Micro – vasculitis, granulomas, focal proliferation of microglial cells

Back 55

Lyme Disease

Front 56

What are the clinical symptoms of Lyme disease?

Back 56

Clinical – (B. burgdorferi transmitted by Ixodes tick) variable symptoms which include meningitis, polyneuropathies, facial nerve palsies

Front 57

There are a number of different viruses that cause Viral meningoencephalitis....what are some?

Back 57

Arthropod-borne (St. Louis, California, Eastern and Western equine, Venezuelan)
Herpes Simplex (HSV-1)
HSV-2
Varicella-Zoster (Herpes Zoster)
Cytomegalovirus
Poliomyelitis
Rabies
HIV

**Just as a note these are in order from 1 to 8

Front 58

How will a viral meningoencephalitis present?

Back 58

Clinical – variable, mental status change, fever, headache, may progress to coma

Front 59

What are the gross findings of Viral meningoencephalitis?

Back 59

Gross – variable, from not much to vascular congestion and intense edema

Front 60

What are the GENERAL things seen on micro for viral meningoencephalitis

Back 60

perivascular infiltrates, microglial nodules, neuron loss, neuronophagia

Front 61

What are the SPECIFIC things seen on micro for viral meningoencephalitis?

Back 61

Herpes-temporal lobe necrosis

Rabies-Negri bodies in hippocampal and Purkinje neurons

HIV-microglial nodules and multinucleated giant cells

KNOW THESE SPECIFICS*****

Front 62

The hemorrhages seen here in the temporal lobe are due to......

Back 62

Herpes simplex virus infection.

Front 63

What will you see micro for herpes viral infection?

Back 63

Viral infections produce mononuclear cell infiltrates microscopically

Front 64

What are fungal and Parasitic Meningoencephalitis?

Back 64

Fungal – Usually only late in disease and primarily in immunocompromised

Front 65

What is the most common cause of Fungal Meningoencephalitis?

Back 65

Most common – Candida, Aspergillus, Mucor, Criptococcus

Front 66

What areas fungal species are seen in endemic areas?

Back 66

In endemic areas – Histoplasma, Coccidioides, Blastomyces following pulmonary or cutaneous

Front 67

What are the 3 main patterns of Fungal and Parasitic Meningoencephalitis

Back 67

Three main patterns

Chronic meningitis – with
AIDS--Toxoplasmosis

Vasculitis – Mucor, Aspergillus

Parenchymal – Candida,
Criptococcus

Front 68

What about Parasitic (protozoal)
Fungal and Parasitic Meningoencephalitis

Back 68

Parasitic (protozoal)

Offenders include malaria, toxmoplasmosis, amebiasis, trypanosomiasis, typhus, Rocky Mountain Spotted Fever, cysticercosis, echinococcosis

Front 69

What parasitic infection is of most concern?

Back 69

Toxoplasmosis is of most concern because of involvement with AIDS (up to 30%)

See abscess, necrosis, chronic inflammation

CT/MRI shows ring-enhancing lesion

Front 70

Disseminated infections can be seen in immunocompromised hosts. Such infections can include fungi.

Back 70

Seen here are branching hyphae of Aspergillus invading a cerebral vessel. Aspergillus likes to invade vessels and produce hemorrhage and thrombosis.

Front 71

Transmissible spongiform encephalopathies are Prion Diseases

Back 71

What is Kuru?


Prion
Host Human
Subacute Spongiform Encephalopathy (SSE);
Fore Tribe – New Guinea; consuming infected brains

Front 72

What is Creutzfeldt-Jakob Disease

Back 72

Prion Dz
Host-human
SSE
Genetic prediposition

Front 73

What is Gerstmann-Straussler

Back 73

Prion disease
Host-human
SSE

Front 74

What is Fatal Familial Insomnia

Back 74

Prion disease
host-human
SSE

Front 75

What is Scrapie?

Back 75

Prion dz
host-sheep
SSE - from scraping their wool off on fences

Front 76

What are the clinical signs of Prion diseases?

Back 76

Clinical
occurs in middle-aged to elderly
Rapid progressive dementia
Death within 6-12 months

Front 77

What are the gross signs of prion diseases?

Back 77

Gross – not much

Front 78

What are the micro signs of prion disease?

Back 78

Micro – spongiform change of cerebral cortex and deep gray matter (caudate, putamen)