Oral self-mutilation in a patient with rhombencephalosynapsys

Rhombencephalosynapsis (RS) is a rare cerebellar malformation. Its essentia l features are the absence of the incisura cerebelli posterior, fusion of t he cerebellar hemispheres, the absence of the velum medullare anterius and nuclei fastigii, and fusion of the dentate nuclei. which are shifted toward s the mid-line. Clinically, affected patients present with signs of cerebel lar and motor disturbances. The present report describes a new patient affe cted by RS. The subject first presented at the age of 22 years because of a psychiatric symptomatology which was characterized by obsessive oral self- mutilation associated with an intellectual disability. Objective evaluation documented dysmorphic features, while neurological examination showed only a slight truncal ataxia. The subject's IQ was 74 on the Wechsler Scale (ve rbal IQ = 79, performance IQ = 74). Psychiatric evaluation with DSM-IV crit eria documented an obsessive-compulsive personality disorder associated wit h emotional instability and oral self-mutilation. The typical picture of rh ombencephalosynapsis was evident on magnetic resonance imaging. Both chromo somal analysis and routine biochemical investigations were normal. The rela tionship between oral self-injurious behaviour and cerebellar malformations is discussed with particular regard to the behavioural aspects of cerebell ar congenital pathology in affective disorders and in autism.