Significance of basal ganglia calcification on computed tomography in children.

We reviewed 6,428 head computed tomography (CT) scans performed on 4,283 children at our institution over a 3-year period and found basal ganglia calcification (BGC) in 48 (1.1%) of the patients. Their mean age at the time of detection was 5.3 years (range: 0.5-20 years); 16 (33%) patients had cancer, 14 (29%) had tuberous sclerosis or congenital infection and 18 (38%) had other medical conditions. All patients with cancer had been treated with radiation therapy, receiving a mean dose of 4,583 cGy (range: 1,800-5,500 cGy) to the diencephalon, and calcifications first became apparent at a median of 10 months after treatment. Other medical conditions included neonatal asphyxia (3), metabolic disease (3) (Kearns Sayre, MELAS, Krabbe's), congenital anomalies (3), meningitis (2), Fahr's disease (1) and others (6). Neurologic symptoms were common in children of all groups, but could not be correlated to BGC changes. Calcium and phosphorus metabolism was evaluated in 19 patients and was abnormal in 1. We conclude that BGC on CT in childhood occur primarily as an aftermath of the cancer treatment or in children with generalized neurologic dysfunction. Many children with BGC are delayed in their development, but calcifications are not directly related to specific forms of neurologic dysfunction. Rather, ther appear to serve as markers for more extensive brain damage.