Clinical · Healthcare · Insights

Improved screening for cognitive change in ALS


Ah, Milano. Home of Armarni, The Last Supper and Panettone…in no particular order of importance, of course! This year Milan was also home to the annual International Symposium on ALS/MND. There was a plethora of high quality research on show this year, particularly at the clinical session on cognitive and psychological change in ALS. A dominant theme of these talks was the issue of effective screening for cognitive-behavioural change in ALS patients. There is increasing recognition of cognitive-behavioural symptoms in ALS, but identifying patients who show such symptoms is troublesome. Clinical settings are limited in time or staff resources. Furthermore, the pervasive use of standardised measures which are not designed with ALS patients’ physical symptoms in mind risks overestimating impairment. Standardised screens might also not be sensitive enough to detect the types of cognitive changes that commonly occur in ALS patients. 

To address these issues, Sharon Abrahams and her colleagues (University of Edinburgh) have devised the Edinburgh Cognitive and Behaviour ALS screen or ECAS. This screen is a 15 – 20 minute measure which assesses several cognitive domains (e.g. language, executive function, fluency, social cognition, memory and visuospatial ability) all the while controlling for the confounds of patients’ motor disability. The unique selling point of this measure is its brief yet comprehensive assessment (most ALS-specific screens only assess executive function) alongside the inclusion of a carer interview designed to detect behavioural symptoms characteristic of FTD (e.g. reduced empathy; increased apathy). Moreover, the screen computes an ‘ALS-specific score’ which estimates performance on domains that have been shown to be susceptible to decline in ALS (executive function, language, fluency, social cognition). It also computes a ‘non-specific score’ which indicates performance on domains that are not strongly associated with the ALS cognitive syndrome (memory, visuospatial ability). Abnormality cut-off scores which indicate the presence and severity of impairment on different domains are also provided. Notably, these scores allow clinicians to determine the type of cognitive and/or behavioural change presenting in patients and tailor their care accordingly. Dr Elaine Niven, a member of the Edinburgh team, presented results from a pilot study which used the ECAS to examine the cognitive-behavioural profiles of 48 ALS patients. The results indicated the measure’s effectiveness as a concise but sensitive screen (see Abrahams et al, 2013 for this study). An interesting observation was that language impairment was highest in the sample (35%), followed by fluency and executive dysfunction (both 23%). These results correspond to other research indicating a higher prevalence of language disruption than executive impairment in ALS patients (see Taylor et al, 2013) and underscore the value in assessing multiple cognitive domains in ALS patients. The ECAS awaits further validation using more detailed neuropsychological assessment in larger patient samples. I suspect that this measure will soon become the gold-standard of ALS cognitive-behavioural screens.

In the second talk, Dr Jennifer Murphy (CA, USA) presented some early findings from her team’s on-going longitudinal study of ALS cognitive change. The study uses three measures to detect cognitive impairment in patients: the ALS-Cognitive-Behavioural Screen (ALS-CBS), a fluency task and a behavioural inventory. Baseline data from 258 ALS patients were presented. Approximately 10 – 15% of patients met criteria for FTD, on the basis of the screening tasks. Of the remaining non-demented ALS patients, approximately 64% and 13% met criteria for cognitive and behavioural change, respectively. Behavioural dysfunction was associated with several variables. These included: lower respiratory function, poorer bulbar functioning, greater overall physical impairment and increased pseudobulbar affect (also known as emotional lability). Lower respiratory function and poorer bulbar functioning were also associated with cognitive subtests measuring concentration and monitoring. While longitudinal data will provide a better indication of causal relationships between these variables, these initial findings identify potential clinical markers for cognitive and behavioural change in patients.

Further evidence for extra-motor change in ALS was provided by a study conducted by Dr Eneida Mioshi and her colleagues (Sydney, Australia) which investigated patient susceptibility to neuropsychiatric symptoms alongside motor symptoms. The results indicated that behavioural symptoms occurred earlier than the development of motor symptoms in the patients, a finding which has considerable theoretical and clinical importance in ALS research. Neuropsychiatric symptoms in ALS support the concept of an ALS-FTD continuum, with non-demented ALS patients displaying similar, albeit less severe, behavioural changes associated with FTD patients. Their early presence may pose additional burden upon caregivers who might be unaware that such changes can occur so early (or at all) in the disease. Decisions regarding the patient’s care are also likely to be affected by the presence of behavioural change. The study joins the others in highlighting the need for frank discussions about possible psychological change in ALS early in the management of patients and their families.

It was encouraging to see the wealth of study dedicated to this area of ALS research. The conference overall offered an exciting glimpse of what is to come in these interesting and emerging fields. If these presentations are anything to go by the next few years are bound to herald some interesting developments in the field.

 

References 

Abrahams S, Newton J, Niven E, Foley J, Bak TH (2013). Screening for cognition and behaviour changes in ALS. Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration. doi:10.3109/21678421.2013.805784

Taylor, L. J., Brown, R. G., Tsermentseli, S., Al-Chalabi, A., Shaw, C. E., Ellis, C. M., … & Goldstein, L. H. (2013). Is language impairment more common than executive dysfunction in amyotrophic lateral sclerosis?. Journal of Neurology, Neurosurgery & Psychiatry84(5), 494-498. doi:10.1136/jnnp-2012-303526

 

Advertisements