Quize of the week Hajer AlZuhair Medical resident

43 years old male patient who is k/c of HIV and came with history of seizures and confusion.CT scan brain was shown What it your differential diagnosis?

CNS toxoplasmosis in HIV patient Epidemiology Among HIV-infected patients in the US, the annual number of toxoplasmosis peaked at more than 10,000 in 1995, dropped sharply to 3643 in 2001, and then decreased to 2985 in 2008 after the introduction of anti-toxoplasma prophylaxis and potent antiretroviral therapy (ART)

CLINICAL PRESENTATION Patients typically present with headache associated with confusion, and fever Focal neurologic deficits or seizures are also common. more profound mental status changes, especially accompanied by N or V, usually indicates elevated intracranial pressure.

DIAGNOSIS A definitive diagnosis of TE requires identification of one or more mass lesions by brain imaging and detection of the organism in a biopsy specimen they usualy prefer to initially treat a seropositive patient with compatible symptoms, signs, and imaging for TE and a brain biopsy is performed in those who do not improve with directed therapy

serology The majority of patients with TE are seropositive for anti- toxoplasma IgG antibodies. Anti-toxoplasma IgM antibodies are usually absent The absence of antibodies to toxoplasma does not exclude the possibility of TE

IMAGING (MRI) is more sensitive than (CT) for identifying the ring- enhancing brain lesions which most AIDS patients with cerebral toxoplasmosis have.

Brain biopsy Definitive diagnosis of cerebral toxoplasmosis is made by pathologic examination of brain tissue

CSF analysis may have mild mononuclear pleocytosis and elevated protein Detection of T. gondii by PCR has demonstrated high specificity (96 to 100 %) but variable sensitivity (50 to 98%) depending on the primers used

Continue.. A presumptive diagnosis can be made if the patient has a CD4 cell count <100/microL and: Is seropositive for T. gondii IgG antibody Has not been receiving effective prophylaxis for toxoplasma Brain imaging demonstrates a typical radiographic appearance (eg, multiple ring-enhancing lesions) If these three criteria are present, there is a 90 percent probability that the diagnosis is toxoplasmosis

Treatment The initial drug regimen of choice is the combination of : Pyrimethamine Sulfadiazine Leucovorin For those patients who cannot take sulfadiazine due to intolerance or history of allergy, pyrimethamine plus clindamycin

Alternative regimens Trimethoprim-sulfamethoxazole Pyrimethamine plus azithromycin Adjunctive corticosteroids should be used for patients with radiographic evidence of midline shift, signs of critically elevated intracranial pressure or clinical deterioration within the first 48 hours of therapy

Duration of therapy For patients who respond, the duration of therapy is typically six weeks

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