We present the neuropsychological and linguistic follow-up of a girl with bilateral perisylvian polymicrogyria during 4 years of gestural and verbal speech therapy. Some researchers have suggested that children with bilateral perisylvian polymicrogyria mentally fail to reach the syntactic phase and do not acquire a productive morphology. This patient achieved a mean length of utterance in signs/gestures of 3.4, a syntactic phase of completion of the nuclear sentence and the use of morphological modifications. We discuss the link between gesture and language and formulate hypotheses on the role of gestural input on the reorganization of compensatory synaptic circuits.