Ms. Tamlyn J. Watermeyer is a doctoral student studying emotional processing and social cognition in Amyotrophic Lateral Sclerosis/Motor Neuron Disease. A researcher at King’s College, London’s Institute of Psychiatry, she presented a paper at the International Symposium on ALS/MND. The symposium took place in Milan, December 6-8, 2013. The abstract for her paper caught my interest. In this email interview, Tamlyn was kind enough to respond in detail to my questions.
Marylee: Apart from the physical changes that happen with ALS, there’s growing evidence that ALS/MND changes the way patients process their feelings. Impaired executive function and loss of empathy can have a big impact on caregivers. You and your colleagues just completed a study where you compared 55 ALS patients to 49 control subjects who otherwise matched them in IQ, mood, years of education, and age. Can you talk tell us whether you found problems with an ALS patient’s decision-making ability?
Tamlyn: We didn’t look at decision-making per se, but the patients in our study were given cognitive tasks which are believed to tap into executive function or processes that may support decision-making in real life. The definition of “executive function” is a controversial topic in psychology. In general it refers to “higher” cognitive processes that supervise “lower” processes that enable reasoning, problem-solving and flexibility of behaviour. Compared to the healthy control participants, some of the patients in our study showed difficulties with tasks requiring abstract and flexible thinking, problem-solving and inhibitory control (the ability to suppress a learned behavioural response).
Marylee: What about other changes in an ALS patient’s emotions, such as the ability to have empathy with others?
Tamlyn: The results of our analyses did not indicate that the patients had problems correctly identifying emotions (happy, sad, angry) from faces. They were also able to “read” the intention and feelings of actors in scenes depicting sarcasm and deceit. However, some patients showed difficulties on a task requiring the inferences of the thoughts and feelings of characters from cartoons and written scenarios. Why they had difficulty on this particular task and not the others might relate to the higher executive demands required by the task.
Separate analyses did indicate that executive dysfunction was related to poorer performance on the tasks assessing the ability to infer emotions and thoughts of others. No differences were found between patients and controls self-ratings of empathic behaviour; however, caregivers rated patients as showing significantly lower levels of some aspects of empathy than patients themselves (see below).
Empathy is an interesting construct to measure in ALS, not only because of the implications for the caregivers of patients, but also because changes in empathic behaviour are common in the behavioural type of frontotemporal dementia (FTD). Research from various fields have associated FTD and ALS at the genetic and neuropathological levels (similar genes and areas of the brain may be involved). Questions remain as to whether the cognitive impairment apparent in some ALS patients is akin (but attenuated) to that seen in FTD patients and whether there might be a cognitive continuum that exists between the disorders, with ALS on one end of the continuum and FTD on the other. That is not to say. however, that ALS patients showing cognitive symptoms will inevitably develop full-blown FTD. In fact, no consensus has been reached as to whether cognitive impairment in ALS progresses with disease. But these observations in ALS patients are interesting as they suggest that the disease may not always be limited to the motor system.
Marylee: Did you find that caregivers were aware of cognitive changes in the people they were caring for?
Tamlyn: We asked caregivers (who were all spouses or partners of ALS patients) to fill out questionnaires relating to patients personalty and cognitive-behavioural change. (The cognitive-behaviour questionnaire included items which assessed patients’ levels of apathy, “executive behaviour” and inhibition). Caregivers rated patients as showing significant changes in personality and behavioural domains since the onset of their illness. (We asked caregivers to rate patients at the time of the interview and approximately two years before the onset of their ALS symptoms). We found that perceived behavioural change, together with severity of limb disability of the ALS patient, significantly contributed to reduced caregiver well being (a composite score of caregiver’s levels of anxiety, depression, burden and strain).
Notably, caregivers reported significantly higher levels of anxiety and depression than the respective patients. Clinicians should be made aware that ALS can bear common but unequal outcomes on patients and their caregivers. Clinical communication with ALS families should emphasise the psychological challenges presented by cognitive-behavioural features, as much as the physical manifestations, of ALS.
Marylee: Did caregivers feel a lack of empathy on the part of the people they were taking care of?
Tamlyn: We asked caregivers to rate different facets of patients’ empathic behaviour (not their own empathy towards the patient). Current models of empathy distinguish between cognitive and emotional components of empathy. The cognitive component relates to the ability to understand another’s perspective or mental state, while emotional or affective empathy refers to the capacity or tendency to respond emotionally to another’s mental state or emotional display.
In our study, caregivers rated patients as showing lower levels of cognitive empathy than patients rated themselves (differences in ratings for affective empathy did not differ significantly), suggesting they felt that patients were less likely or less able to imagine the cognitive viewpoint of another. Exploratory analyses found that the greater the discrepancies between patients’ and caregivers’ ratings for cognitive empathy, the greater the caregivers’ dissatisfaction with their relationship with the patient. As the study was cross-sectional (data collected all at one time point), we were not certain whether lower cognitive empathy in patients (as perceived by caregivers) may cause caregivers’ reduced marital satisfaction or whether low marital satisfaction (either before or after disease onset) might influence caregivers’ reporting of patients’ empathic behaviour.
Future longitudinal research is needed to investigate whether or not the discrepancies between patients’ and caregivers’ perceptions of patients’ empathy become more disparate with time; and if discordant perceptions between the spousal partners contribute to caregivers’ experience (in terms of well being and marital satisfaction) over the duration of the patient’s illness. This design would provide a better indication of causal relationships between patients’ empathy and caregivers’ outcomes.
Marylee: Why is it difficult to measure cognitive changes in patients with ALS?
Tamlyn: Testing cognition over time in ALS patients presents some challenges. Cognitive tasks need to be adjusted to take into account the patients’ physical disability (as had been done in this study). Otherwise the tasks may overestimate patients’ impairment. Not all standardised tasks can be adjusted, and quite often they are verbally based, which can be tricky for patients with bulbar symptoms that worsen with the disease course. Also, testing can be tiring and a greater commitment for patients in the end stage of the disease; loss of data from attrition in longitudinal studies is common. Nonetheless, longitudinal studies of ALS cognition do exist, with some, but not all, finding modest cognitive deterioration in patients over time.
Marylee: Did your research discover anything about the progression of cognitive changes?
Tamlyn: The study wasn’t longitudinal. We relied on retrospective reports of cognitive-behavioural and personality change, which is open to bias such as the memory recall of the respondent.
Marylee: What would you like to add?
Tamlyn: I would just like to highlight that not all patients in the study showed signs of cognitive-behavioural impairment. ALS is a highly variable disease and there is no strong evidence to suggest that cognitive impairment is an inevitable consequence of the disorder. That said, I believe more awareness regarding the possible psychological changes that may present in ALS is warranted. I would encourage frank discussions between clinicians, patients and their families regarding such changes early in the disease course.
Tamlyn Watermeyer [email@example.com]
King’s College London
Insitute of Psychiatry
Centre of the Economics of Mental Health/Section of Community Health
16 De Crespigny Park