Brain computed tomography still plays a critical role in the diagnosis of Aicardi-Goutières syndrome

Objectives:Aicardi-Goutières syndrome (AGS) is a rare genetic neurological disorder with different clinical manifestations, heterogeneous genetic varieties and leukodystrophic imaging features. Magnetic resonance imaging (MRI) is mostly found normal therefore,calcification in brain computed tomography (CT) is still very valuable for diagnosis,The aim of this study is to review the clinical, radiological and molecular diagnostic findings with AGS presenting in childhood. Methods:We reviewed the clinical records and brain MRI/CT images of 16 patients whom had a molecular diagnosis of AGS. Results:Fourteen individuals with AGS admitted in the first year of life. Patients presented with developmental delay(87.5%);spasticity(87.5%);speech delay (62.5%);trunk hypotonia(75%);and seizures(56.2%).Brain MRI showed white matter abnormalities(62.5%), and cerebral atrophy(50%).MRI images included leukodystrophic findings but did not show a specific diagnosis.Brain CT was performed in 12 patients, and 11 of them showed small, punctate, multifocal calcifications in the lentiform nuclei, deep cerebral and cerebellar white matter (91.6%).Calcification suggestive image was observed in only five patients with brain MRI.Homozygous mutations were identified in TREX1(25%),RNASEH2B(25%),RNASEH2A(6.3%),RNASEH2C (6.3%),SAMHD1 (6.3%).Heterozygous mutations in 3 patients with TREX1(18.8%),2 patients with IFIH1(12.5%) considered as epileptic encephalopathy spectrum.In follow-up improvement in myelination was observed in the control MRIs of four patients. Conclusions:With these clinical and radiological findings, we aimed to raise awareness about AGS and to show the importance of brain CT. CT is not preferred because it is an old technique and risk of radiation especially with children.In these cases, the age at diagnosis is delayed due to nonspecific clinical and MRI findings.CT is instructive where brain MR findings are not diagnostic.
Keywords: Aicardi-Goutières syndrome; TREX-1; calcification; leukodystrophy.