Classically, motor neurone disease (MND) has been considered a pure motor syndrome which spares aspects of cognition, behaviour and emotional processing. A number of studies in recent years have established that a proportion of patients with FTD develop features of frank MND. Moreover, some patients with classic MND also go on to manifest features of FTD although estimates of the degree of overlap have varied widely.
Our group has been investigating the frequency of behavioural and emotional changes in patients who present with classic motor neurone disease. Around 10% of patients develop mark changes in behaviour and personality and meet a diagnosis of frontotemporal dementia. A much higher proportion, around 50%, have subtle but potentially important changes of this type. We are now exploring these patients in greater detail using tests of social cognition, emotion processing and language ability coupled with brain imaging.
The primary aim is to identify the prevalence and pattern of cognitive changes in MND patients, and the potential impact on activities of daily living, decision making and on carer burden.
A parallel study is looking at the frequency of motor abnormalities in patients with frontotemporal dementia to see if features of motor neurone disease can be found.
