Suprabulbar Paresis, Congenital

Clinical Features

Called the Worster-Drought (1974) syndrome because of the review of 200 cases by that physician, congenital suprabulbar paresis is characterized by selective weakness and impairment of movement of the orbicularis oris muscle, tongue and soft palate leading to dysarthria and troublesome drooling. In severe cases there is involvement of the pharyngeal and laryngeal muscles in early life. The child cannot protrude his tongue or move it within the mouth and is unable to round the lips to whistle or blow, but since other facial muscles are unaffected, he can smile normally and close his eyes. Worster-Drought (1974) noted familial occurrence in 12 of his 200 patients.

Patton et al. (1986) described 4 affected males in 3 sibships of 3 generations of a family. They suggested autosomal dominant inheritance with variable expression and reduced penetrance. All 4 were mentally retarded and the proband was microcephalic; 3 had epilepsy and the fourth had an abnormal EEG. Transmission through males excluded X-linked inheritance. In an earlier report of 82 cases, Worster-Drought (1956) found that 7 families contributed 17 affected persons. These included mother and son, father and 2 children, and 2 adult sisters and the daughter of 1 of them.

Clark and Neville (2008) reviewed phenotypic features and family data of 170 children with a WDS phenotype or perisylvian polymicrogyria, including 33 with bilateral and 20 with unilateral congenital perisylvian polymicrogyria (see CBPS; 300388). WDS was defined as affecting more than 1 bulbar modality, such as speech or feeding, with upper motor neuron bulbar signs on examination. Other features included decreased IQ, pyramidal signs, seizures, and hyperactivity. There were 19 multiplex families, with 15 clearly having the WDS phenotype. Inheritance patterns suggested X-linked transmission in some families and autosomal dominant transmission with reduced penetrance in other families. There was not a clear relationship between perisylvian structural changes and clinical phenotype. Clark and Neville (2008) suggested that there is a spectrum of perisylvian disorders, some with visible MRI changes and others with only functional deficits, and that WDS is a manifestation of certain perisylvian disorders. The authors concluded that perisylvian disorders are heterogeneous but that familial reports implicate a role for genetics in the etiology.

Molecular Genetics

Associations Pending Confirmation

For discussion of a possible association between Worster-Drought syndrome and variation in the SLC9A1 gene, see 107310.