Frontal lobe is the brain's way of modifying and interposing constraints on basic reflexive behaviors. It has a key role in higher mental functions such as motivation, planning, social behavior, and speech production. Frontal lobe syndrome reflects damage to the prefrontal regions of the frontal lobe. It is characterized by deterioration in behavior and personality in a previously normal individual. Cerebrovascular disease is one of major causes of frontal lobe syndrome.

After weaking up from comma caused by subarachnoidal haemmoraghia and embolisation of arteria communicans, 48 year old patient was radically changed. His wife reported “He is not the same man”. He became erretic, euphoric, noncritical, sexually desinhibed, impulsive and easy frustrabile even agressive. His circadiary rythm was disrupted, he was sleaping invariably. Computer tommograpy shown “multiple ischemic lesions bifrontoparietalis”. After treatment some of symptoms are set under control but some persisted.

There is no other part of the brain where lesions can cause such a wide variety of symptoms. These symptoms can roughly be divided into three main categories: cognitive, emotional and behavioural. Combination of presented symptoms can make diagnostic confusion. It may often be confounded with two psychiatric disorders: mania (or hypomania) and antisocial personality disorder.

Treatment of such patients is ambiguous and failures can be often expected.