Infectious Disease

Question 1

What are the different types of meningitis?

Answer 1

Bacterial (most common), Viral, Fungal, Mycobacterial

Question 2

What are the signs/symptoms of Bacterial Meningitis?

Answer 2

fever, HA, meningismus, photophobia, vomiting

Question 3

What are the common organisms that cause bacterial meningitis?

Answer 3

newborns - group B strep
child-young adult - Neisseria, strep pneumo
elderly - strep pneumo, listeria
Neurosurgical pts - staph aureus (MRSA)

Question 4

How does the bacteria invade in meningitis?

Answer 4

colonization of the nose into the veins across the BBB or CSF leak allows it in with head trauma. Invasion of CSF leads to exudate formation, increased ICP, and inflammed arteries (think stroke!)

Question 5

Tx of bacterial meningitis

Answer 5

get antibiotics going empiracally - ceftriazone (crossses BBB), vancomycin and maybe ampilcillin for listeria
steroids to reduce swelling

Question 6

CSF in bacterial meningitis

Answer 6

cloudy, pressure > 180, WBC (PMNs) > 1000, protein > 40, glucose < 40, gram stain shows bacteria!

Question 7

What are the signs/symptoms of Viral Meningitis?

Answer 7

HA, fever, meningismus - but less severe than bacterial and no changes in level of consciousness

Question 8

What characterized viral meningitis?

Answer 8

self-limiting. caused by enterovirus, herpes (HSV2), measles, mumps, arboviruses. Tx bedrest, fluids, analgesia. CSF shows WBC < 500 mostly lymphocytes.

Question 9

What is fungal meningitis?

Answer 9

rare, but severe form of meningitis - usually seen in immunosuppressed (cancer or AIDS) - that may be subacute or chronic. Typical organisms of Cryptococcus (most common), Aspergillus, Candida. S/Sx: HA, low grade fever, malaise, fatigue, confusion and dementia may present

Question 10

CSF in fungal meningitis

Answer 10

hazy, WBC , 200 lymphocytes, high protein, glucose low but > 20, eosinophilia

Question 11

What is mycobacterial meningitis?

Answer 11

It is a rare form of meningitis seen in immunocompromised or malnourished pts caused by tuberculosis that has reactivated from a previous infection.

Question 12

CSF in mycobacterial meningitis

Answer 12

hazy, yellowish, WBC < 200 lymphocytes, protein high >300, glucose very low

Question 13

Viral encephalitis

Answer 13

encephalitis characterized by changes in LOC (seizures/focal deficits), HA, fever, meningismus - but pt looks sicker than viral meningitis. Most often caused by HSV1, but also can be caused by arboviruses. Tx: IV acyclovir ASAP & hydration.

Question 14

CSF of viral encephalitis

Answer 14

mostly normal with slightly elevated WBCs, overtime WBC, RBC and protein will increase!

Question 15

Rabies Virus

Answer 15

virus transmitted by infected saliva into a wound and then enters neurons and moves in a retrograde fashion to the brain. 2-12 days latent, causes viral prodrome, encephalitis, change LOC, painful spasms, can’t swallow, death in 2-10 days. Tx: antibodies and vaccination prior to sx onset

Question 16

Bacterial encephalitis (neurosyphilis)

Answer 16

caused by Treponema Pallidum, primary infection is a painless ulcer that becomes latent and then can cause encephalopathy. early sx: meningitis, cranial neuritis, cerebrovascular. late sx: sensory ataxia, dementia w/ psychosis, Charcot joints.

Question 17

Bacterial encephalitis (lyme disease)

Answer 17

Caused by Borrellia burgdorferi. Sx: spreading rash (erythema migrans), arthritis, mild meningismus, HA, neck pain. Dx: blood cultures w/ western blot. tx: doxycycline or ceftriaxone

Question 18

Herpes Zoster

Answer 18

Reactivation of varicella zoster cirus that is common in elderly or immunocompromised. Causes vesicular skin eruptions in dermatomal distributions and dysesthesia (tingling). Dx: rash, skin biopsy, PCR. Tx: acyclovir
Pain may persist after recovery - Postherpetic neuralgia

Question 19

Bacterial Brain Abscess

Answer 19

Usually caused by a mix of anaerobic and aerobic organisms, it presents with HA and focal sx and will show up as ring enhancing lesions due to inflammed tissue w/ dark necrotic center. Tx with antibiotics

Question 20

Toxoplasmosis

Answer 20

The parasite, Toxoplasma, can cause brain abscesses that look like many ring enhancing lesions on CT. It is very responsive to Tx. Major DDx is primary CNS lymphoma.

Question 21

Cysticercosis

Answer 21

The parasite Pork Tapeworm can cause cysticercosis presenting as calcified lesions seen on unenhanced CT. Also invades the liver, muscle, brain and eye.

Question 22

empyema

Answer 22

build up of pus in a body space

Question 23

Epidural abscess

Answer 23

infx in the epidural space of the spine (usually Staph Aureus) that causes a low grade fever and back pain that can lead to spinal cord damage and sepsis.

Question 24

Common opportunistic infections in HIV/AIDS

Answer 24

toxoplasmosis, tb, cyptococcus, syphilis, progressive multifocal encephalopathy, cytomegalovirus

Question 25

Progressive multifocal encephalopathy

Answer 25

reactivation of JC virus resulting in white matter leasions that presents in the immunocompromised. Tx: immune support.

Question 26

AIDS dementia

Answer 26

HIV is neurotropic and can damage the brain. With increased viral loads, AIDs pts can develop disorientation and confusion. Tx: decrease the viral load.

Question 27

Creutzfeld-Jacob Disease

Answer 27

Prion disease that causes spongiform encephalopathy when spread from infected tissue. It remains latent for a while and then progresses rapidly and the CSF is clear unless tested for specific proteins. Can present with myoclonic jerks or muscle twitches that worsen to ataxia overtime.

Question 28

Botulinum Toxin

Answer 28

blocks neurotransmission by cleaving synaptobrevin (vesicle docking protein) usually causing facial or eye muscle paralysis first, then flaccid paralysis throughout (top down)

Question 29

Tetnus toxin

Answer 29

Toxin that cleaves synaptobrevin to inhibit GABA and glutamate release resulting in uncontrolled neuronal firign and stiffness (lockjaw). Early anti-toxin may be life saving.