Evaluation of Syndromic Craniosynostosis in Children

Examination

A full multidisciplinary examination must be carried on all children with syndromic craniosynostosis. This examination will involve pediatricians, neurosurgeons, craniofacial plastic surgeons, ophthalmologists, and ENT surgeons.

ICP monitoring

• Early identification of elevated ICP: ICP monitoring is useful and safe in the management of babies and children with syndromic and nonsyndromic craniosynostosis to help evaluate the need to normalize ICP and thereby reduce the risk of long-term sequelae of ICP elevation. Overnight or 24-hour ICP monitoring identifies patients with raised ICP who would benefit from early surgical intervention and has become a significant factor in the staged surgical management of these patients.

Ophthalmological screening

• Ocular and oculomotor abnormalities: Patients with syndromic craniosynostosis have a high percentage of ocular and oculomotor complications, such as optic atrophy, exorbitism, strabismus, functional amblyopia, and ptosis of the eyelid. Some of these symptoms are related to the shape, direction and position of the orbital cavity, others to the paralysis of oculomotor muscles, and still others to raised ICP. 

ENT screening

• Airway: All patients require ENT assessment at presentation to determine the status of the airway.
• Hearing and ear: It is important that the ENT service examine the child for pinna abnormalities, external canal atresia, middle ear abnormalities, stapes fixation, and sensorineural deafness.

Laboratory Tests

Genetic and molecular testing

While the clinical assessment is the best guide to management and prognosis, there are several instances where the knowledge of the mutation may aid in this process.

• FGFR testing: A level 1 screen will detect most iatrogenic mutations causing Apert, Crouzon, Pfeiffer, Muenke, and Saethre-Chotzen syndromes (FGFR1 exon 7, FGFR2 exons 8 and 10, FGFR3 exons 7 and 10, TWIST1 exon 1). A level 2 screen will detect the more rare Crouzon and Pfeiffer syndrome mutations (FGFR2 exons 3, 5, 11, 14-17). In atypical cases, Crouzon syndrome may be difficult to diagnose in the first few months, and alertness to this possibility can anticipate future complications.
• TWIST1 testing: Mutations in TWIST1 causing Saethre-Chotzen syndrome are usually iatrogenic, but in approximately 20% of cases a complete deletion of the gene in 7q21.1 is responsible (37). A substantial deletion of the gene is significant and may be associated with additional learning difficulties. This information is useful to the surgeon since developmental delay might otherwise be attributed to raised ICP or complications of previous surgeries.

Radiologic Tests

Although most skull deformity syndromes are identified by clinical evaluation, imaging can help to confirm or refine the diagnosis. Imaging is also used to assess the severity of a syndrome and to assist in its classification. The selection of modality, such as CT or MRI, is based on the clinical presentation and symptomatology. CT and MRI are used in a complimentary fashion or may be done exclusively.

CT with 3D reconstruction

• Treatment planning: A 3D reconstruction of a CT scan is typically employed for treatment planning. It is used to evaluate the skull for the presence and degree of sutural involvement as well as the shape of the skull. It can also assess any associated facial and intracranial abnormalities. It should be used sparingly for monitoring after interventions because of the exposure of tissues to a high radiation dose. This concern is particularly applicable to the cornea.

MRI

• Evaluation of suspected, associated brain abnormalities: MRI is mainly used to determine whether associated brain abnormalities, such as white matter immaturity, agenesis of the corpus callosum, and heterotopias, are present. The inclusion of the craniocervical junction and cervical spine helps to rule out Chiari malformations, commonly associated with syndromic craniosynostosis, and other cervical spine abnormalities.
• Evaluation of intracranial circulation: MRV is helpful to identify anomalies in the venous system.

 Electrodiagnostic Tests

• Visual evoked potentials: Some centers use visual evoked potentials as an indicator of ICP rather than direct ICP monitoring.

Neuropsychological Tests

• Establish baseline and follow: Neurodevelopmental testing is part of the routine work-up. Such testing yields information about cortical functioning before and after cranial vault remodeling by comparing the child’s mental and psychomotor scales to a normogram. It thereby helps to quantify whether the child is delayed and surgery has reduced the severity of the delay.
• Family support: The psychologist also works with the parents, helping them to meet the various needs of their child and may be the key for a family’s optimal and successful patient journey.

Correlation of Tests

• Multidisciplinary team planning: When the patient has been fully evaluated and all test results are available, the case is discussed at a multidisciplinary team meeting. Typically, this team will consist of core members (neurosurgeons, plastic surgeons, maxillofacial surgeons, ophthalmologists, ENT surgeons, anesthesiologists, and radiologists) with other consultants participating on a variable basis.
• Clinical status, presence of elevated ICP, and progression: Decisions for intervention are taken on the basis of syndrome, age, comorbidities, rate and pattern of head growth, presence or absence of elevated ICP, presence of visual impairment, and airway or swallowing compromise. Each case is unique and must have individualized treatment plans.