Focal Neurological Disease in Patients with Acquired Immunodeficiency Syndrome

Abstract

Focal neurological disease in patients with acquired immunodeficiency syndrome may be caused by various opportunistic pathogens and malignancies, including Toxoplasma gondii, progressive multifocal leukoencephalopathy (PML), cytomegalovirus (CMV), and Epstein-Barr virus-related primary central nervous system (CNS) lymphoma. Diagnosis may be difficult, because the findings of lumbar puncture, computed tomography (CT), and magnetic resonance imaging are relatively nonspecific. Newer techniques have led to improved diagnostic accuracy of these conditions. Polymerase chain reaction (PCR) of cerebrospinal fluid specimens is useful for diagnosis of PML, CNS lymphoma, and CMV encephalitis. Recent studies have indicated the diagnostic utility of new neuroimaging techniques, such as single-photon emission CT and positron emission tomography. The combination of PCR and neuroimaging techniques may obviate the need for brain biopsy in selected cases. However, stereotactic brain biopsy, which is associated with relatively low morbidity rates, remains the reference standard for diagnosis. Highly active antiretroviral therapy has improved the prognosis of several focal CNS processes, most notably toxoplasmosis, PML, and CMV encephalitis.

Ring enhancing intracranial lesion responding to antituberculous treatment in an HIV-infected patient

“…Most patients with cerebral toxoplasmosis showed a CD4+ cell count below 100 cells/mm 3 , and in the case of primary CNS lymphoma, below 50 cells/mm 12,16 . However, intracranial tuberculomas or tuberculous brain abscesses are not uncommon with CD4+ cell count above 100 cells/mm 3(15) .…”

Meningoencephalitis and new onset of seizures in a patient with normal brain CT and multiple lesions on MRI

“…A wide range of clinical findings, including altered mental state, seizures, weakness, cranial nerve disturbances, sensory abnormalities, cerebellar signs, meningismus, movement disorders, and neuropsychiatric manifestations are seen in TE [1][2][3]. The characteristic presentation usually has a subacute onset with focal neurologic abnormalities.…”

“…However, in 15% to 25 % of cases, the clinical course may be more abrupt, with seizures or cerebral hemorrhage. Aditionally, up 10 % of patients may www.bjid.com.br present with diffuse encephalitis, without any visible focal lesions [2]. Suspicion of TE in AIDS patients with neurological symptoms usually arises when neuroimaging studies demonstrate multiple lesions, but a solitary lesion may account for nearly one third of patients [7].…”

“…Presumptive diagnosis is considered in patients with less than 200 CD 4 + T-lymphocyte cells/ mL, anti-Toxoplasma IgG antibody in the serum, consistent clinical features, characteristic neuroimaging studies, and response to empirical anti-Toxoplasma therapy [1][2][3]. Failure to respond to therapy after two weeks, indicated by persistence or worsening of either symptoms or the mass lesions observed on radiographic imaging dictates the need for a diagnostic stereotactic biopsy [10].…”

“…Toxoplasmic encephalitis (TE) is the most common cerebral mass lesion in patient with acquired immunodeficiency syndrome (AIDS) [1], and is due to reactivation of latent infection as a result of progressive loss of celular immunity. Most patients (>80%) who develop disease have CD 4 cell counts of < 100 cell/mL [2]. The frequency of TE in AIDS patients varies from about one fourth to one half of cases in the absence of antimicrobial prophylaxis [3].…”