Radiological Case of the Month FREE

AN 8-YEAR-OLD BOY with human immunodeficiency virus (HIV) was seen for routine evaluation. At the time of HIV diagnosis (age 4½ years), his CD4 cell count was 17 cells/µL (reference range, >1000 cells/µL), and findings from neurologic examination were normal. Treatment was started with zidovudine, trimethoprim sulfate, rifabutin, and monthly intravenous immunoglobulin, but the CD4 cell count remained low. At age 6½ years, he had been performing poorly in school. Findings from neurologic examination showed 2 to 3 beats of ankle clonus bilaterally. A magnetic resonance imaging study (MRI) had been obtained. The patient later developed anemia, leukopenia, elevated creatine phosphokinase levels, and elevated lactic dehydrogenase levels, all of which resolved when zidovudine was discontinued. At age 7 years, he was hospitalized for persistent fever with no source found. Nephrotic syndrome was diagnosed based on renal biopsy findings showing minimal changes of the disease, and he had intermittent hypertension; both resolved by age 8½ years after treatment with didanosine, stavudine, and ritonavir. CD4 cell counts improved to 646 cells/µL.

He was evaluated for increasing mood swings and learning problems at age 8½ years. Findings from physical examination revealed a blood pressure of 136/77 mm Hg; pulse, 96 bpm; height, 121.9 cm (10th percentile); and weight, 21.0 kg (5th percentile). Neurologic evaluation showed increased tone in the upper extremities, brisk (2+ to 3+) patellar reflexes, and 5 to 7 beats of clonus at both ankles. Because of his worsening neurologic signs and symptoms, the MRI was repeated (Figure 1, Figure 2, and Figure 3), and a magnetic resonance angiogram was obtained (Figure 4). Protein S showed normal antigenic activity and decreased functional activity. During the next 18 months, the clonus increased and was spontaneous in both lower extremities, the left greater than right. He developed left-sided weakness with a tendency to carry the left arm and hand in a hemiparetic posture. Repeated MRI with magnetic resonance angiogram showed no changes.