1 - Neuroradiology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal.
2 - Neuroradiology Department, Hospital de Braga, Braga, Portugal.
3 - Neuroradiology Department, Hospital Dona Estefânia, Centro Hospitalar Universitário de Lisboa Central, Lisboa, Portugal
- 45th ESNR Annual Meeting, 14-18 Setembro, Lisboa
- Neuroradiology (2022) 64 (Suppl 1):S1-S165 https://doi.org/10.1007/s00234-022-03012-w
Introduction: fetal MRI is a widely used technique to confirm, complement or exclude questionable prenatal ultrasound (US) findings and plays an essential role in evaluating fetuses with suspected US findings and /or positive family history. Kinked brainstem is a rare finding in fetal neuroimaging, typically seen in association with other CNS abnormalities.
Clinical case: a 26-year-old woman with a history of endometriosis, prolactinoma and ovarian teratoma, with no previous pregnancies and no history of inbreeding undergoes prenatal US evaluation at 21 weeks and 4 days of gestation with evidence of microcephaly and multiple central nervous system (CNS) malformations. Three days later fetal MRI is performed, showing a complex CNS malformation, characterized by kinked brainstem, marked hypoplasia of the cerebellum, complete agenesis of the corpus callosum, cavitation of the ganglionic eminences, malformation of the midbrain-diencephalic junction and microcephaly with delayed sulcation and gyration pattern. α-dystroglycanopathy, X-linked hydrocephalus, tubulinopathy or lissencephaly with cerebellar hypoplasia were considered as the main differential diagnosis. At 22 weeks and 6 days of gestation she was hospitalized for medical termination of pregnancy, and the postmortem anatomopathological examination confirmed the imaging findings. Genetic study identified a mutation involving the TUBA1A gene (c.601G>A).
Conclusion: prenatal identification of a kinked brainstem should prompt evaluation of the multiple possible associated CNS malformations, allowing an attempt to distinguish between main possible diagnosis, such as X-linked hydrocephalus (L1CAM mutation), tubulinopathy (TUBA1A mutation) or α-dystroglycanopathies (e.g., Walker-Warburg syndrome). Although definitive diagnosis depends on genetic confirmation, fetal MRI provides the necessary resolution to detect complex CNS malformations, to further assist genetic evaluation, management, and counseling.
Key Words: fetal MRI; kinked brainstem; tubulinopathy; TUBA1A mutation