Neuro of immunocompromised Flashcards
Causes of immunodeficiency
Inherited (common variable immunodeficiency - B cell), congenital (thymic alplasia - T cell), protien-losing illness, malignancy (lymphomas, CLL etc.), infection (HIV), iatrogenic (drugs, immunosuppressants e.g. steroids, radiotherapy, malnutrition)
Course of HIV infection
CD4 count declines and HIV viral load increases, increased risk of developing infections and tumours, severity greater with lower CD4 count, most AIDS diagnosis occurs at CD4 < 200
How can HIV affect the nervous system?
Opportunistic infections (tumours), increased risk for other conditions (stroke, MI), direct CNS and PNS infection, primary infection (meningoencephalitis, vasculitis), toxoplasmosis, tuberosclerosis, primary CNS lymphoma
Investigations in immunocompromised
Imaging (contrast CT or MRI), Lumbar puncture (proteins, cultures), CD4 count, Blood tests, syphilis serology, brain biopsy
Management of immunocompromised
Treat toxoplasmosis, steroids for oedema, AED’s for seizures, consider PCP prophylaxis, treat HIV at 2 weeks with antiretrovirals
What are the potential effects of HIV treatment?
Controlled HIV infection, leading to immune reconstitution, potential toxicities, interactions with other medications, immune reconstitution syndrome (IRIS), creating of sanctuary sites
What issues may be relevant to someone diagnosed with HIV?
Need for lifelong treatment, impact on driving, other STIs, impact on sexual partner and children, impact on employment, lifestyle, insurance, GP records, stigma, reckless transmission
Late diagnosis of HIV
24% diagnosed too late for effective treatment, 24% CD2 count <22mm3 at diagnosis
How is HIV diagnosed?
Antibodies in serum detectable in > 99% infected people 12 weeks post-exposure, 4th generation ab/ag tests positive within 2-4 weeks of infection, Viral RNA, salivary screening tests, take confirmatory samples of CD4 count to assess degree of immunosuppression if test positive
Suspected primary HIV infection
Seroconversion illness 60-80% of people 2-4 weeks post-infection. symptoms include: fever, maculopapular rash, myalgia, pharngitis, headache/aseptic, meningitis, lymphadenopathy. During this time the patient is highly infectious.
What are the neurological indicator diseases for HIV? (regardless of age, gender and ethnicity)
Cryptococcal meningitis, cerebral abscess, cerebral toxoplasmosis, aseptic meningitis, encephalitis, PML, leucoencephalopathy, primary lymphoma, SOL, unknown cause neurological symptoms if possible seroconversion
