A Brazilian man recovering from a stroke has turned into a philanthropist after damage to parts of his brain changed his personality in a way previously unheard of by doctors.

The 49-year-old senior manager of a large corporation found that he could not stop giving away money and spending cash liberally on sweets, food and drinks for children he met in the street. His wife told doctors her husband’s generosity had led to significant family distress and almost bankrupted them.

The man, referred to as Mr A, suffered a stroke triggered by high blood pressure. This led to bleeding in his subcortical region, an area immediately below the cerebral cortex, associated with higher-level thinking and decision-making.

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Psychiatrists at the University of Rio de Janeiro concluded that the stroke had disrupted Mr A’s emotional behaviour and judgement. Typical symptoms following damage to this region include depression, which Mr A has also displayed.

However, Dr Leonardo Fontenella, a member of the team who examined Mr A, reported in the journal Neurocase in August that the man’s symptoms of “excessive and persistent generosity resembled an impulse control disorder”. He said these personality changes were normally “characteristic symptoms of frontal lobe damage (and) have less often been described in patients with focal subcortical injuries.”

Dr Larry Goldstein, a neurologist at the Stroke Centre at Duke University in North Carolina, said: “Although the observation of personality change is not that unusual, this particular one is apparently novel.”

Mr A told doctors he was aware of his behaviour and no longer wanted to work because he had “seen death close up (and) wanted to enjoy life which is too short”.

The researchers were particularly interested in what was driving the altruism, especially as the symptom is the opposite of disorders such as hoarding and sociopathy. Further research may shed light on which brain areas affect “the delicate balance between altruism and egoism, which make up one of the pillars of ordinary social motivation and decision-making,” they said.