Definition: Cloverleaf skull or kleeblattschadel is a rare malformation caused by synostosis of multiple cranial sutures. It can be associated with hydrocephalus, proptosis, and hypoplasia of the midface and cranial base.

Synonyms: Craniosynostosis.

Incidence: Rare outside the associated syndromes (see below).

Etiology: Depend on the associated syndrome, most are de novo mutation of the FGFR1-3.

Diagnosis: The findings are usually quite obvious with the usual oval shape of the head at the level of the BPD replaced by the trilobate skull: one frontal protrusion and two postero-lateral protrusions.

Genetic anomalies: Most are de novo mutation of the FGFR1-3.

Differential diagnosis: Hydrocephalus from other causes, although the head shape is usually normal.

Associated anomalies: Many syndrome present with cloverleaf skull including most of the acrocephalopoly(syn)dactylies (Crouzon, Pfeiffer, Carpenter, Apert…). It is also typical of the type II form of thanatophoric dysplasia (another FGFR mutation).

Prognosis: When associated with hydrocephalus the outcome is usually poor with frequent death in infancy.

Management: The surgical management of patients with cloverleaf skull deformity is aimed at relieving the intracranial hypertension and correcting the aesthetic appearance. By a process of repositioning and modifying segments of the skull satisfactory results both as regards relief from intracranial hypertension and preservation of visual acuity, and from the aesthetic viewpoint can now be achieved[1],[2].

Reference:

[1] Zuccaro G, Dogliotti P, Bennum R, Monges J: Treatment of cloverleaf skull syndrome. Childs Nerv Syst 1996 Nov;12(11):695-8

[2] Resnick DK, Pollack IF, Albright AL Surgical management of the cloverleaf skull deformity. Pediatr Neurosurg 1995;22(1):29-37; discussion 238