CNS Infections and Diabetic Neuropathy (Exam 2)

Question 1

What is meningitis?

Answer 1

-inflammation of the meninges surrounding the brain and/ or spinal cord
-meningoencephalitis refers to inflammation of only the meninges surrounding the brain
-most commonly caused by bacterial or viral infection

Question 2

What are the 3 meningitis pathogenic classifications?

Answer 2

1) acute pyogenic (bacteria causes pus formation)
2) acute aseptic (viral)
3) chronic (bacterial)

Question 3

Which bacteria most commonly infects newborns with acute pyogenic meningitis?

Answer 3

E. coli and group B strep

Question 4

Which bacteria most commonly infects older adults with acute pyogenic meningitis?

Answer 4

steptococcus pneumoniae and listeria monocytogenes

Question 5

Which bacteria most commonly infects adolescents with acute pyogenic meningitis?

Answer 5

neisseria meningitidis

Question 6

How is acute pyogenic meningitis diagnosed?

Answer 6

spinal tab and blood culture

Question 7

What are the clinical features of acute pyogenic meningitis and acute aseptic meningitis?

Answer 7

-fever
-headache
-eyes sensitive to light
-neck stiffness
-irritability

note: the symptoms are the same for both types but acute pyogenic is more severe

Question 8

Most cases of acute aseptic meningitis is caused by enteroviruses. The other 20% of cases are caused by what bacteria?

Answer 8

borrelia burgdorgeri (spirochete bacteria that causes lyme disease)

Question 9

What is chronic meningitis caused by?

Answer 9

-TB (mycobacterium TB)
-lyme disease (spirochetal)
-neurosyphilis (spirochetal)
-fungus (cryptococcal)
-malaria protozoan (parasite)
-toxoplasmosis (parasite)

Question 10

Who is most commonly infected with meningitis?

Answer 10

anyone who lives in close quarters
-children in daycare centers
-dorm rooms
-military barracks

Question 11

What is neurosyphilis?

Answer 11

bacteria infection caused by treponema pallidum (STD, spirochete bacteria)

Question 12

What are the tertiary stages of syphilis that affect the CNS?

Answer 12

1) meningovascular neurosyphilis (chronic meningitis)
2) paretic neurosyphilis (kills cortical neurons= dementia)
3) tabes dorsalis (loss of joint proprioception, pain sensation and discriminative touch)

Question 13

What is tabes dorsalis?

Answer 13

-stage 3 of neurosyphilis
-damage to sensory axons in dorsal spinal nerve roots, dorsal horn, and dorsal white columns (medial lemniscus tract)
-damaged fasciculus gracilis will result in loss of discriminative touch and vibration
-damaged fasciculus cuneatus will result in loss of joint proprioception

Question 14

What is lyme disease?

Answer 14

-bacterial infection caused by borrelia burgdorferi (spirochete bacteria)
-transmitted through the deer tick
-erythema migrans (bulls eye rash) occurs at tick bite site
-flu like symptoms
-knee pain

Question 15

What is neuroborreliosis?

Answer 15

-lyme disease that spreads to CNS
-chronic meningitis
-facial nerve palsy unilateral or bilateral
-polyneuropathies
-encephalopathy

Question 16

What is herpes simplex encephalitis?

Answer 16

-viral infection
-encephalitis of the temporal and frontal lobes
-frontotemporal lobar degeneration
-major cause of fatal sporadic encephalitis in US
-loss of cortical neurons
-fatal to newborns and immunocompromised

Question 17

What is varicella zoster virus (herpes zoster)?

Answer 17

-viral infection
-initially chicken pox (cutaneous only)
-latent phase in adults is shingles (neurological manifestations)
-chicken pox is highly contagious contact virus that causes infection of keratinocytes
-shingles virus is dormant in dorsal root or trigeminal ganglia
-chicken pox is random vesicular blisters
-shingles is vesicular blisters that follow a dermatome

Question 18

What is rabies?

Answer 18

-severe viral encephalitis
-transmitted to humans by the bite of a rabid animal (its in the saliva)
-carried to the CNS via retrograde axoplasmic transport!!!!!
-encephalitis
-negri bodies within CNS neurons
-widespread neuronal degradation
-foaming at the mouth and aversion to swallowing and water hydrophobia (due to contracture of the pharyngeal musculature)

Question 19

What is progressive multifocal leukoencephalopathy?

Answer 19

-fancy word for common wart
-viral infection caused by JC polyomavirus
-demyelination of oligodendrocytes causes encephalitis (typically only effects immunocompromised, MS most as risk)
-enlarged oligodendrocyte nuclei containing glassy amphophilic viral inclusions
-lesions show an area of demyelination and reduced number of axons

Question 20

What is wernicke’s encephalopathy?

Answer 20

-thiamine (vit B1) deficiency long term will damage mammillary bodies
-inability to absorb thiamine from intestines due to chronic alcoholism, gastric disorders, including carcinoma, chronic gastritis, or persistent vomiting
-hemorrhage and necrosis in the mammillary bodies and the walls of the 3rd and 4th ventricles
-lesions in the dorsomedial nucleus of the thalamus
-psychotic symptoms
-nystagmus
-untreated can lead to korsakoff syndrome (create memories that never happened and short term memory is distorted)

Question 21

What is diabetic neuropathy?

Answer 21

-distal peripheral nerve damage (finger tips, toes, hands, feet)
-leaky microvessels caused by chronic DM type 1/2
-degeneration of axons and or myelin sheath
-distal symmetric polyneuropathy (numbness, paresthesia (pins and needles), and pain)
-skin ulcers which can lead to amputation
-uncontrolled hyperglycemia damages microvessels supplying axons which leads to degeneration due to decreased oxygen and NGF
-diabetic neuropathy can also affect autonomic neurons