NeurometPlus

Incidence

AD. The aggregate frequency of craniosynostosis is about 0.4-0.6 per 1000 live births. Unnafected parents have 1% of reccurrence chance. Patients have 50% chance of reccurrence.

Clinical Characteristics

The aggregate frequency of craniosynostosis is about 0.4-0.6 per 1000 live births. It has been emphasized the fundamental principle that it is the accessory malformations, not the particular affected sutures, that allows differentiation among isolated craniosynostosis and the craniosynostosis syndromes. For example, patients with the Apert, Pfeiffer, or Crouzon syndromes may have premature synostosis of the coronal sutures, but it is the finger fusion (Apert), broad thumbs (Pfeiffer), or normal hand findings (Crouzon) that guides the diagnosis. The head shape reflects the sutures that are fused. Synostosis of the coronal suture (roughly along a line connecting the ears) produces a "tower" skull (acrocephaly) with a short forehead-occiput distance (brachycephaly). Synostosis of the sagittal suture (from forehead to occiput) produces an elongated head (scaphocephaly) with a prominent occiput. Rarely, several sutures are fused to produce the severe anomaly called clover-leaf skull or Kleebattschädel anomaly. Depending on the cause and distribution of fused sutures, it is the changes in skull shape that produce complications in the craniosynostosis disorders. With synostosis of the coronal (ear to ear) suture, undergrowth of the midface is common with malformation of the sphenoid bones behind the nose and flattening of the cranial base. Infants may have a huge fontanelle (soft spot), extending from the lower forehead to the occiput. The nasal bridge is depressed and the nasal septum may be deviated. Narrowing of the posterior choanae (nasal passages) may occur and produce respiratory distress or heart failure. The small midface may also restrict the orbits, causing the eyes to bulge and become injured because of exposure and inadequate tearing. Palatal anomalies (cleft soft palate, highly arched palate) together with flattened cheekbones and protrusion of the jaw cause dental misalignment. Dental eruption may also be delayed. In Pfeiffer syndrome, there is risk for upper and lower airway obstruction. The smaller mouth and throat may cause symptoms of obstructive sleep apnea (cessation of breathing during sleep) and heart failure due to inadequate oxygenation (cor pulmonale). Surgical treatment involving resection of the palate, adenotonsillectomy, or even tracheostomy (breathing tube through neck into the windpipe) may be considered for symptomatic patients. Lower airway obstruction can result from narrowing or inflexibility of the trachea, causing difficulty in clearing secretions and possible damage from tracheal suctioning. Fusions of the neck spine can also occur in these syndromes, mandating cervical spine x-rays before attempting intubation for general anesthesia. Narrow respiratory structures can impair ear drainage, causing chronic otitis and hearing loss. In Pfeiffer syndrome, cervical spine fusion may be more common and complex, and anomalies of the lower backbone (sacrum) may occur. Hearing deficits and optic nerve problems also occur, along with dental anomalies (extra teeth) and skeletal defects (club foot, fusions of the arm bones, short arms). More severe synostosis with clover-leaf skull anomaly and severe ocular proptosis may occur in Pfeiffer syndrome, and these patients often have an early death. Unaffected parents who have a child with Pfeiffer syndrome will have a recurrence risk of less than 1%. Affected individuals, who will mostly have normal life expectancies and reproductive potential, will have a 50% recurrence risk with each pregnancy.

Precipitants

no

Provocation Tests

no

Diagnostic Procedures

Clinical diagnosis.