Not guilty by reason of epilepsy. Post-ictal delirium and psychosis resulting in violent offending

To the Editor

Emergency staff assisting a collapsed post-ictal 54-year-old (R) in his home were alarmed when their ‘unconscious’ patient leaped up, seized a carving knife and attacked. R then struck responding police officers so forcefully that he split a riot shield in half. Officers later described his strength as ‘superhuman’. Undeterred by stun gun deployment, R was ‘tasered’ twice and pepper-sprayed before collapsing from another generalised seizure.

Following medical stabilisation, R was charged with assault and remanded to a forensic psychiatric hospital. He displayed impaired cognition, euphoric mood and persecutory delusions. He had no recollection of the index offence or preceding week. His wife reported R had consumed excess alcohol 7 days previously and that frequent seizures, poor medication adherence, insomnia and bizarre behaviour followed.

R has a 30-year history of complex partial epilepsy originating in the left anterior temporal lobe with secondary generalisation. His compliance with antiepileptic medication was erratic. Admission sodium valproate level was low at 98 mmol/l. He had no psychiatric history until age 48 when he was compulsorily admitted on the first of three occasions following seizure clusters. Post-ictal symptoms included agitation, elevated mood, paranoid delusions and multi-modal hallucinations. R’s psychosis resolved quickly without inter-episode symptoms. He was placed on risperidone and improved rapidly, however resisted continuing antipsychotics. Previously he had once behaved aggressively post-ictally. He had no forensic history and was described as ‘easy-going’.

R’s symptoms resolved rapidly in hospital. He was shocked to hear details of the attack.

In court, R was found not guilty by reason of insanity on two accounts of assault with a weapon. He was judged to have been suffering from post-ictal delirium/psychosis and not been conscious of the nature and quality of his act – an insane automatism – defined in the New Zealand courts as “Action without conscious volition…in short doing something without knowledge of it, and without memory afterwards of having done it…” (R v Cottle [1958] NZLR 999). R was considered at risk of recurrent post-ictal aggression and received disposition under the Mental Health Act for compulsory treatment.

Episodic psychoses of epilepsy have been identified primarily in patients with temporal lobe epilepsy, particularly complex partial seizures with secondary generalisation (Toone, 2000) and are strongly associated with poor seizure control. Post-ictal resistive violence (combativeness resisting restraint) is not uncommon (Marsh and Krauss, 2000). Directive violence such as that demonstrated by R is rare (e.g. Mendez, 1998). We are only aware of two New Zealand cases where a defendant was acquitted on account of epilepsy-related insane automatism (R v Cottle, 1958 NZLR 999; Q v Hesketh CRI 2002-441-795013. Napier HC T 020688 [unreported]). A review of UK cases was critical of the legal concept of ‘insane automatism’ in relation to epilepsy (MacKay and Reuber, 2007). In R’s case we consider that an insanity finding and disposition under the Mental Health Act was the best clinical outcome to reduce the risk of future violent events to R and to the public. Currently R remains well treated in the community on intramuscular risperidone and sodium valproate with improved seizure control and no further aggressive outbursts.