An 8-year-old male patient was born full-term via vaginal delivery, with unremarkable prenatal and birth history. Patient has been previously diagnosed with Hunter syndrome. Sudden onset of neurologic symptoms including slurring of speech and decreased sensorium prompted hospital consult. The patient’s mother claimed previous unwitnessed episodes of head trauma.
On non-enhanced cranial CT scan, acute to subacute subdural haemorrhage along the right cerebral convexity is noted (Fig. 1). Three-dimensional (3D) reconstruction of the bone window incidentally revealed fused sagittal and bilateral lamboid sutures (Fig. 2A-D). The patient’s skull is dolicocephalic and microcephalic (Fig. 3A-B). On skeletal survey, aside from the absence of the sagittal and bilateral lambdoid sutures, anterior beaking of the inferior aspect of some of the lumbar vertebral bodies were observed, as seen in cases of Hunter syndrome. (Fig. 4A-C).
Multisutural cranial synostosis is rare by itself and syndromic in approximately 15% of cases.  In this report, we are presented with a case of bilateral lambdoid and sagittal suture craniosynostosis, discovered as an incidental finding. This type of craniosynostosis usually occurs as an isolated finding. Recent publications reported only one syndrome for which it may be associated, namely Opitz Syndrome.  Hunter syndrome is under the group of mucopolysaccharidoses, and is due to deficient iduronate-2-sulfatase, which primarily affects males. Usual calvarial ﬁndings include a J-shaped sella turcica and thickened skull. Other skeletal manifestations may include odontoid dysplasia, anterior beaking of the lower thoracolumbar vertebral bodies, shortening of the long bones and thickened ribs and clavicles. Limited literature has been published regarding its relationship with craniosynostosis. [3,4,5] Bilateral lambdoid and sagittal sutures craniosynostosis is also known as Mercedes Benz syndrome. This pattern comprises only 0.3-0.7% of the known cases of craniosynostosis and is heterogenous, which may be syndromic, chromosomal or isolated in nature. Early fusion of the lambdoid and sagittal sutures in these patients results in step-like deformity of the occiput. Secondary effects of the marked local skull growth restriction in posterior fossa include compensatory expansion of the anterior fossa seen as frontal bossing. [1,2,3,5] Syndromic cases of bilateral lambdoid and sagittal craniosynostosis are rarely seen such as in our case. Recent study shows that for Hunter syndrome, more than two sutures were closed in 67% of cases; however, there were no reported cases with sagittal and bilateral lambdoid craniosynostosis.  Diagnostic imaging is essential to identify the fused suture and associated skull deformities, determine other intracranial pathologies, possible complications, surgical planning and post-treatment evaluation of patients. Computed tomography (CT) with three-dimensional (3D) reconstruction is the primary imaging technique used in cases of craniosynostosis, due to its superior bone depiction.  For the definitive management of bilateral lambdoid and sagittal craniosynostosis, early surgery is suggested to maximise neurologic potential.  This is usually done in the first year of life, when the calvarial bones effectively heal, and as soon as the infant appears able to tolerate the procedure. Most of the cases with this pattern usually require a single cranial vault remodeling procedure. [7,8] The choice of suitable surgical procedure must be based on the patient’s pre-operative head appearance and presence of associated anomalies. [2,7,8] In conclusion, bilateral lambdoid and sagittal suture synostosis appears to arise from aetiologically heterogeneous group of disorders, with syndromic associations infrequently occur. Written informed patient consent for publication has been obtained.
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