Oral self-mutilation in a patient with rhombencephalosynapsys

Rhombencephalosynapsis (RS) is a rare cerebellar malformation. Its essential features are the absence of the incisura cerebelli posterior, fusion of the cerebellar hemispheres, the absence of the velum medullare anterius and nuclei fastigii, and fusion of the dentate nuclei, which are shifted towards the mid-line. Clinically, affected patients present with signs of cerebellar and motor disturbances. The present report describes a new patient affected 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 (verbal IQ = 79, performance IQ = 74). Psychiatric evaluation with DSM-IV criteria documented an obsessive-compulsive personality disorder associated with emotional instability and oral self-mutilation. The typical picture of rhombencephalosynapsis was evident on magnetic resonance imaging. Both chromosomal analysis and routine biochemical investigations were normal. The relationship between oral self-injurious behaviour and cerebellar malformations is discussed with particular regard to the behavioural aspects of cerebellar congenital pathology in affective disorders and in autism.