Organic neuropsychiatry: a treatable cause of suicidal behaviour

A previously well 29-year-old man, on holiday in Portugal, developed myalgias, drenching night sweats, overwhelming fatigue and an umbilical rash. Two weeks later, he developed worsening anxiety, agitation and obsessive behaviours, progressing over 3 weeks, together with memory difficulty, hyperphagia, paraesthesiae in limb extremities and de novo vivid nightmares. On examination, there were generalised fine jerky movements in all limbs, consistent with myoclonus. He had bilateral papilloedema. Mini-mental state examination score was 25/30, with points dropped on short-term recall and serial sevens. Additional testing (three stage Luria) demonstrated frontal dysexecutive impairment. He was reviewed in clinic 1 week later, having attempted suicide the day before. He had hung himself at home with a wire noose, after taking six paracetamol tablets. Fortunately, the noose broke. Immediately afterwards, he was remorseful, frightened and surprised by his actions. He now disclosed delusional ideas that he would be unjustly imprisoned either in this world or another one, which had driven him to the attempted hanging. As a child, he had been inclined to obsessive hand washing and his father had suffered severe depression. Until this illness, he had worked as a high level manager and was due for a promotion. ### Question 1 How would you summarise the salient features of the case and formulate a balanced differential diagnosis? ### Comment The case can be summarised as a subacute history of progressive cognitive deterioration culminating in a suicide attempt in a high-functioning young man, with prominent psychiatric features including agitation and obsessions, and a florid paranoid delusional system (on the background of possible obsessional–compulsive disorder as a child), amnesia, myoclonus and papilloedema. There was no history of substance abuse and no seizures. The differential diagnosis is wide and includes infective and postinfective aetiologies, inflammatory and metabolic conditions (summarised in the table 1). View this table: Table 1 Balancing the differential diagnosis Variant Creutzfeldt–Jakob …