HIV and Neurology Flashcards
What is the central nervous system?
consists of the brain and spinal cord
Note: Both brain and spinal cord are enclosed in the meninges
What is the peripheral nervous system?
consists of the nerves and ganglia outside of the brain and spinal cord
What is a lumbar puncture?
is a procedure in which a needle is inserted into the spinal canal to collect cerebrospinal fluid (CSF) to help diagnosing e.g. meningitis
HIV neurological focal lesions causes?
- toxoplasmosis
- tuberculoma
- cryptococcoma
- pyogenic abscess
- lymphoma
- progressive multifocal leukoencephalopathy
HIV neurological diffuse disease causes?
- cryptococcal meningitis
- tuberculous meningitis
- CNS syphilis
- HIV dementia
Diagnosing focal lesions?
CT scan
What is the problem with diagnosing ‘neurological’ HIV?
- CSF results are sometimes not helpful
- imaging studies are rarely diagnostic
- brain biopsy is invasive
Therefore: empiric management is often necessary – anywhere in the world
Diagnosing diffuse disease?
LP
What are seizures?
Seizures are characterized by loss of consciousness and involuntary movements
Ddx for seizures in HIV neurology?
- Toxoplasmosis
- intracerebral involvement of disseminated TB (brain tuberculoma or TB meningitis)
- brain abscesses
- cryptococcal and bacterial meningitis and intracerebral tumors (e.g. CNS lymphoma)
Two key things to ALWAYS remember in the management of HIV infected patients with neurology?
- HIV infection does not prevent the development of a non-HIV related problem, so consider “normal causes”
- Opportunistic problems are related to the CD4 (+) cell count
Note: If the count is > 200-300, the problem is probably not related to the HIV infection
At what CD4 count do we consider a person immunocompromised?
CD4 count <200
What is toxoplasmosis?
One of the most common space occupying lesions especially in a person with a CD4 count <200 (usually < 100)
Etiology of Toxoplasmosis?
infection with the Toxoplasma gondii parasite found in cat feces and contaminated food like meat
- can also be caused by reactivation of a previous disease
Pesentation of toxoplasmosis?
sub-acute and focal
Most common cause of seizures in HIV patients?
toxoplasmosis
Describe the CSF of toxoplasmosis infected patient?
non specific
Diagnosis of toxoplasmosis?
- On CT scan multiple ring enhancing lesions are seen (1/3 single lesion)
- The best diagnostic test is response to treatment as usually the response happens within 10-14 days
Treatment of toxoplasmosis?
Treatment: high-dose bactrim (4 tabs bd) for 28 days, followed by three months of 2 tabs bd
NB: bactrim is a combination of the antibiotics sulfamethaxazole and trimethoprim
Bactrim can be used as a prophylaxis for?
- toxoplasmosis
- malaria
- PCP
- diarrhea
Etiology of cryptococcosis and TB?
Treatment?
Cryptococcosis and tuberculosis more frequently cause meningitis infections, but in individual cases they can also cause focal lesions in the brain
- Treatment is similar to CM and TBM
What is a bacterial brain abscess?
Treatment?
a focal, intra-cerebral infection which develops into a collection of pus
- Treatment : Broad-spectrum antibiotic or even a combination of antibiotics should be given e.g. ceftriaxone plus metronidazole
What is a primary CNS lymphoma?
Treatment?
Primary CNS lymphoma is a cerebral mass lesion seen in patients with advanced HIV disease (usually CD4 <50 cells)
Treatment: is not very effective and prognosis is poor
What is meningitis?
If there is an inflammation of the meninges (meningitis)
Features of menigitis?
- headache
- neck stiffness
- altered mental status
- photophobia
- character changes
Causes of meningitis?
- bacterial
- fungal
- viral
- mycobacterial
CSF results for bacterial meningitis?
- increased polymorphs
- mildly increased lymphocytes
- increased proteines
- decreased glucose
- negative serum CrAg
CSF results for mycobacterial meningitis?
- mildly increased polymorphs
- increased lymphocytes
- increased protein
- decreased protein
- negative serum CrAg
CSF results in viral meningitis?
CSF results in fungal meningitis?
- mildly increased polymorphs
- increased lymphocytes
- increased protein
- decreased glucose
- positive serum CrAg
Common symptoms of stroke in HIV patients?
Symptoms of stroke (e.g. hemiparesis, aphasia) in younger patients are seen relatively commonly in HIV positive patients
Risk factors for stroke in HIV?
Traditional risk factors such as hypertension or diabetes are often absent
What causes stroke like symptoms?
opportunistic infection as a cause of the symptoms
1. intracranial TB
2. syphilis
3. VZV
4. cryptococcal meningitis
HIV associated disease that causes stroke?
HIV-associated cerebral vasculitis has been reported as the etiology of stroke in up to 20% of young HIV-positive stroke patients large South African series
Spinal cord disease and HIV?
- Spinal TB should be considered especially in upper motor neuron disease (=> X-ray spine). If there are suggestive signs of TB, TB treatment has to be started
- If TB is improbable because hyperreflexia and radiological signs are absent, a clinically carefully monitored treatment trial with steroids seems warranted
Peripheral neuropathy and HIV?
- Usually occurs in HIV+ patients at late stages with varying severity
- Poorly understood aetiology (could be related to malnutrition and resultant wasting of peripheral nerves, or neurotoxic effect of cytokines), also secondary to NRTI use e.g. AZT
Clinical features of peripheral neuropathy?
- Burning pain, paresthesia
- Decrease ankle jerk
- Normal strength but can progress to muscle weakness
Treatment of peripheral neuropahty?
Symptomatic Tx: Ibu, Carbamazepine, Amitryptillin
CNS syphilis and HIV?
Syphilis can involve the CNS in two stages:
Secondary (aseptic meningitis)
Tertiary (meningovascular, dementia, tabes dorsales)
Diagnosing CNS syphilis?
Our syphilis test is for plasma only
No CSF test is available => if positive in plasma and clinic fits=> treat!
