CNS Infections Flashcards
What are some causes of a brain abscess?
- Contiguous spread
- Hematogenous seeding w/ bacteremia
- Trauma
- Cryptogenic
What are the clinical manifestations of a brain abscess?
Presence of headache, seizures, nausea and vomiting, and focal neurologic signs
Uncommon: fever, nuchal rigidity
What diagnostic tests are commonly performed for brain abscesses?
MRI & CT Scan commonly ordered, blood cultures for bacteremia
LP should NOT be performed (risk herniation)
What are some features of a paraspinal abscess?
Usually due to bacteremia (staph aureus most common); requires surgical drainage to prevent cord compression; osteomyelitis of vertebral bodies
What are the most common locations of a paraspinal abscess?
Posterior & thoracolumbar > cervical
What are some infectious etiologies of chronic meningitis?
Tuberculosis, cryptococcus, lyme disease, syphilis, coccidioidomycosis, histoplasmosis
What are features of the general paresis type neurosyphilis?
Personality, affect, reflexes, eye symptoms, sensorium, intellect, speech abnormalities
What are features of the tabes dorsalis type neurosyphilis?
Ataxia, shooting pains, sphincter disturbance, peripheral neuropathy, cranial neuropathies
What is neurocysticercosis?
Brain infection caused by infection with Taenia solum (tapeworm in pigs)
What are some noninfectious etiologies of chronic meningitis?
Neoplasms, sarcoidosis, vasculitis, drug induced (NSAIDs)
What are the differences between meningitis and encephalitis?
Meningitis - no altered mental status & infection of meninges
Encephalitis - altered mental status & infection of brain
CSF exam similar in both
What are some etiologies of encephalitis?
Viral (HSV - common), bacterial pathogens, spirochetes, parasites, drugs, vasculitis, mycoplasma…
What is acute disseminated encephalomyelitis (ADEM)?
Postinfectious encephalitis occurring 5-21 days after a viral illness; multifocal neurologic symptoms
Treatment: glucocorticoids –> complete recovery
What type of organism often infects diabetics with uncontrolled sugar levels?
Mucor (Fungus)
What type of brain abscess is related to frontal sinus disease and osteomyelitis?
Cranial epidural abscess
Is a subdural abscess a medical emergency?
Yes. Headaches and seizures are common signs
A patient’s blood work is positive for staph bacteremia and currently is running a 103 fever and reports of severe back pain limiting her walking. What is your first suspected diagnosis?
Paraspinal abscess
Surgical drain required
What lab test would you do for a suspected case of lyme meningitis?
Synthesis index. Antibodies in the CSF will be greater than that in the serum.
What does your CSF values look like with viral encephalitis?
Increased lymphocytes
Cell count 500 seen in HSV, CTFV, CEV
HSV-1 is the most common etiology of Herpes Encephalitis. What is a unique symptom / sign in patients with this?
Seizures / status epilepticus –> temporal lobe affected often
Your patient presents with acute hemorrhagic encephalitis. His friend says they had been swimming in the lake nearby. What do you diagnose?
Encephalitis due to naegleria fowleri
CSF: High PMN / low glucose
99% mortality
How is Creutzfel Jakob Disease spread and what are some signs?
CJD is spread by cadaveric tissue.
You see myoclonus, cerebellar ataxia, and dementia.
