Radiographic and Tomographic Study of the Cranial Bones in Children with the Idiopathic Type of West Syndrome.

ABSTRACT

BACKGROUND: Neither radiological phenotypic characteristics nor reconstruction CT scan has been used to study the early anatomical disruption of the cranial bone in children with the so-called idiopathic type of West syndrome. MATERIAL AND METHODS: The basic diagnostic measures and the classical antiepileptic treatments were applied to these children in accordance with the conventional protocol of investigations and treatment for children with West syndrome. Boys from three unrelated families were given the diagnosis of the idiopathic type of West syndrome, aged 7, 10 and 12 years old. Parents underwent extensive clinical examinations. Three parents (age range of 28-41 year) were included in this study. All children showed a history of intellectual disabilities, cryptogenic epileptic spasms and fragmented hypsarrhythmia. These children and their parents were referred to our orthopedic departments because of variable skeletal deformities. Variable forms of skeletal deformities were the motive for the families to seek orthopedic advice. A constellation of flat foot, torticollis and early-onset osteoarthritis were observed by the family doctor. Apparently, and from the first clinical session in our practice, we felt that all these children are manifesting variable forms of abnormal craniofacial contour. Thereby, we immediately performed detailed cranial radiological phenotypic characterization of every affected child, as well as the siblings and parents, and all were enrolled in this study. All affected children underwent whole-exome sequence analysis. RESULTS: The craniofacial phenotype of all children revealed apparent developmental anatomical disruption of the cranial bones. Palpation of the skull bones showed unusual palpable bony ridges along different sutural locations. A 7-year-old child showed abnormal bulging over the sagittal suture, associated with bilateral bony ridges over the squamosal sutures. AP skull radiograph of a 7-year-old boy with West syndrome showed facial asymmetry with early closure of the metopic suture, and other sutures seemed ill-defined. A 3D reconstruction CT scan of the skull showed early closure of the metopic suture. Another 3D reconstruction CT scan of the skull while the patient was in flexion showed early closure of the squamosal sutures, pressing the brain contents upward, causing the development of a prominent bulge at the top of the mid-sagittal suture. A reformatted 3D reconstruction CT scan confirmed the bilateral closure of the squamosal suture. Examination of the parents revealed a similar skull radiographic abnormality in his mother. A 3D reformatted frontal cranial CT of a 35-year-old mother showed early closure of the metopic and sagittal sutures, causing a mid-sagittal bony bulge. A 10-year-old boy showed an extremely narrow frontal area, facial asymmetry and a well palpable ridge over the lambdoid sutures. A 3D axial reconstruction CT scan of a 10-year-old boy with West syndrome illustrated the asymmetry of the posterior cranial bones along the lambdoid sutures. Interestingly, his 28-year-old mother has been a client at the department of spine surgery since she was 14 years old. A 3D reconstruction CT scan of the mother showed a noticeable bony ridge extending from the metopic suture upwards to involve the sagittal suture (red arrow heads). The black arrow shows a well demarcated bony ridge over the squamosal suture. A 3D reconstruction CT scan of the skull and spine showed the thick bony ridge of the metopic and the anterior sagittal as well as bilateral involvement of the squamosal, causing apparent anterior narrowing of the craniofacial contour. Note the lumbar scoliosis. A 12-year-old boy showed brachycephaly. A lateral skull radiograph of a 12-year-old boy with West syndrome showed premature sutural fusion, begetting an abnormal growth pattern, resulting in cranial deformity. The nature of the deformity depends on which sutures are involved, the time of onset and the sequence in which individual sutures fuse. In this child, brachycephalic secondary to craniosynostosis, which occurred because of bilateral early ossification of the coronal sutures, led to bi-coronal craniosynostosis. Thickened frontal bones and an ossified interclinoid ligament of the sella turcica were encountered. The lateral skull radiograph of a 38-year-old mother with a history of poor schooling achievements showed a very similar cranial contour of brachycephaly, thickening of the frontal bones and massive ossification of the clinoid ligament of the sella turcica. Maternal history revealed a history of multiple spontaneous miscarriages in the first trimester of more than five times. Investigating his parents revealed a brachycephalic mother with borderline intelligence. We affirm that the pattern of inheritance in the three boys was compatible with the X-linked recessive pattern of inheritance. Whole-exome sequencing showed non-definite phenotype/genotype correlation. CONCLUSIONS: The aim of this study was sixfold firstly, to refute the common usage of the term idiopathic; secondly, we feel that it could be possible that West syndrome is a symptom complex rather than a separate diagnostic entity; thirdly, to further detect the genetic carrier, we explored the connection between the cranial bones in children with West syndrome with what has been clinically observed in their parents; fourthly, the early life anatomical disruptions of the cranial bones among these children seem to be heterogeneous; fifthly, it shows that the progressive deceleration in the development of this group of children is highly connected to the progressive closure of the cranial sutures; sixthly, we affirm that our findings are novel.