Amount and Distribution of Intracranial Calcification in Symptomatic and Asymptomatic Primary Familial Brain Calcification

BACKGROUND AND OBJECTIVES: In clinical practice, it can be difficult to differentiate between intracranial calcifications related to primary familial brain calcification (PFBC) or aging. Also, little is known about the consequences of the amount of intracranial calcifications in patients with PFBC. Therefore, we aimed to compare the amount and distribution of intracranial calcifications in persons with PFBC with controls and between asymptomatic and symptomatic PFBC cases. METHODS: This was a case-control study including patients with PFBC and controls. Controls received a CT of the brain because of a trauma and had at least some basal ganglia calcification. The Nicolas score and volume of calcification were used to quantify intracranial calcifications on the CT scans. Receiver operating characteristic curves were obtained to calculate optimal cutoff points to discriminate between cases and controls. Mann-Whitney U tests and logistic regression, adjusted for age and sex, were used to compare the amount of calcification. RESULTS: Twenty-eight cases (median age 65 years, 50.0% male) and 90 controls (median age 74 years, 46.1% male) were included. Calcification scores were higher in cases (median volume: 4.91 cm(3) against 0.03 cm(3), p < 0.001, median Nicolas score: 26.5 against 2.0, p < 0.001) than controls. Calcifications were also more diffusely distributed in cases. To differentiate between cases and controls, optimal cutoff points were ≥0.2 cm(3) for the calcification volume and ≥6.0 for the Nicolas score. Calcification was higher for symptomatic than asymptomatic cases (calcification volume: 13.62 cm(3) against 1.61 cm(3), p = 0.01, Nicolas score: 39.0 against 15.5, p = 0.02). After adjustment for age and sex, the Nicolas score remained significantly higher in symptomatic patients, and the calcification volume did not. DISCUSSION: Patients with PFBC had more severe intracranial calcifications, and these calcifications were more diffusely distributed through the brain compared with controls. Symptomatic patients with PFBC might have more intracranial calcifications than asymptomatic persons.