Background The diagnostic category of pervasive developmental disorders (PDD) refers to a group of disorders characterized by delays in the development of socialization and communication skills. Symptoms may include problems with using and understanding language, difficulties relating to people, objects and events, as well as difficulties in changing routine or familiar surroundings, repetitive body movements or behaviour disorders. The behaviour disorders (aggressive behaviours, SIB) can occur and manifest with a large spectrum of clinical symptoms; they usually can be treated with antipsychotic medications. However, when no response to antipsychotics is observed, episodes of aggressive behaviour could be related to epilepsy, occurring in the context of high emotional arousal, anger or fear.

Methods We report the case of a 18-year-old man diagnosed with PDD presenting auto-aggressive behaviour non-responding to neuroleptic medication. The symptoms began when he was 14-year-old. Clinical evaluation showed recurrent episode of excessive hyperactivity and severe auto mutilation, such as biting himself. PET imaging with F-18 2-fluoro-2-deoxyglucose (F-18 FDG) was performed for epilepsy work-up.

Results PET Imaging showed a focal hypo metabolic lesion in the right temporo-parietal region, highly suggestive for an epileptic focus.

Treatment with anti-epileptic medication was initiated and 2 weeks later the self injurious behaviour disappeared with no recurrence 12 months later.

Conclusions Evaluation of more cases of this subset of PDD patients with epilepsy presenting as behaviour disorders by 18F-FDG PET may suggest a possible role in determining an epileptic focus and might in addition potentially help to monitor treatment response.