Figure 1, Figure 2, and Figure 3. Magnetic resonance image at age 8½ years. Adjacent proton-weighted axial sections show ectasia (aneurysmal dilation) beginning at the carotid siphon and extending into proximal middle cerebral artery.
Figure 4. Magnetic resonance angiogram at age 8½ years. Coronal reconstruction in the frontal plane shows a large fusiform aneurysm extending from the carotid siphon into the proximal middle and anterior cerebral arteries.
Neurologic abnormalities are documented as occurring frequently in HIV-infected infants and children.1 General symptoms range from developmental regression to hyperactivity and learning disabilities. Corticospinal tract degeneration may occur with clinical clonus and hyperactive stretch reflexes.2 Localized neurologic deficits may also occur, usually secondary to infection with pathogenic or opportunistic organisms or lymphoma. Progressive multifocal leukoencephaly occurs late and can cause localized or general symptoms.3 Vascular abnormalities are described in HIV-infected infants and children. Bleeding secondary to thrombocytopenia, thromboses secondary to bacterial or fungal infection, and cardiomyopathy with consequent embolization occur.3 Drug-induced vasculitis, Henoch-Schöenlein purpura, and varicella-induced vasculitis may be present.
Recently, a number of HIV-infected children were reported to have remarkable aneurysmal dilation of the large cerebral vessels, particularly the Circle of Willis.4- 11 Children with this abnormality usually present with an acute intracerebral event. Their age is past infancy, and they are usually severely immunologically compromised.5 Only rarely is a neurologic event the initial symptom of HIV infection.
The cause of the aneurysmal changes of vessels is unknown, although the aneurysms may be congenital rather than inflammatory. Many patients, including our own, have normal findings from scans prior to the acute neurologic event. Postmortem studies show arterial medial fibrosis, destruction of internal elastic lamina, and intimal hyperplasia.5,6,10 Speculation suggests that bacterial or fungal infection plays a role in some cases. Varicella infection has been implicated,5 as has HIV, as a causative agent.7 Therapy has been problematic because of the crucial location and nature of the aneurysms.
Our patient showed progression of neurologic signs during the following 2 years despite a marked rise (and subsequent fall) in his CD4 cell count. He remains fully functional in activities of daily living. Because of the surgical risk, no intervention has been attempted. He continues to be monitored closely, and his HIV is treated aggressively pharmacologically.
Accepted for publication December 21, 1999.
Presented as a poster at Southern Society Pediatric Research, New Orleans, La, February 7, 1998.
Reprints: Dianne S. Elfenbein, MD, Department of Pediatrics, University of South Florida, 17 Davis Blvd, Suite 308, Tampa, FL 33606.
Radiological Case of the Month. Arch Pediatr Adolesc Med. 2001;155(7):850. doi:10.1001/archpedi.155.7.849