Following a significant brain injury, the person who has sustained significant injury to the frontal lobes and other associated areas may present with changes in personality and behaviour. These changes arise from impairments in executive functioning and are often referred to as Dysexecutive Syndrome (also known as Frontal Lobe Syndrome). Significant changes in personality and behaviour may lead to the person experiencing difficulties in interpersonal relationships which has a negative impact on all aspects of their life.
Pre-injury personality traits, which were previously relatively innocuous or even helpful, may be exaggerated as a result of executive functioning impairment e.g. a previously appropriately assertive individual may present as inappropriately assertive and aggressive following brain injury or a previously sociable person may become overly talkative. New and sometimes unhelpful personality traits may also occur following brain injury (e.g. aggressive tendencies in a previously placid individual or uncharacteristic sexually disinhibited behaviour).
Sometimes changes in personality and behaviour are relatively minor and only noticeable to the people who knew the person best before their brain injury. However following a significant brain injury, a spectrum of severity of change is observed in both personality and behaviour.
For some individuals the changes in personality and behaviour may be very significant and represent a marked and persistent alteration in personality and behaviour. The expression of emotions, needs and impulses may be particularly affected. This is referred to as Organic Personality Disorder.
Characteristic features of Organic Personality Disorder include reduced impulse control, reduced empathy, emotional lability, irritability, aggressive outbursts, socially inappropriate behaviour and sexually disinhibited behaviour.
Changes in personality and behaviour are undoubtedly one of the most distressing after-effects for family and friends. The person may be unaware of the changes in himself/herself. This may be associated with poor social judgement and lack of insight into the potential consequences of their behaviour upon themselves or others. Unfortunately, specific alterations in personality (e.g. irritability, aggressive tendencies, disinhibited behaviour, reduced impulse control) may lead to the development of challenging behaviours.
Please note that formal psychometric assessment of executive functioning may not always demonstrate evidence of impairment. Comprehensive assessment should include observation of the person in a range of different settings and gathering information from the person, their family, carers and other health and social care professionals. Functional Analysis of Behaviour is helpful and specialist advice may be necessary.
It is important that we do not attribute negative or difficult behaviours arising from executive functioning impairment as being deliberate, vindictive or purely due to pre-injury personality traits. It is most likely that prior to the brain injury, the person would have been perfectly willing and able to modify and adapt their behaviour according to the social situation.