Progressive neurological disorders are incurable disorders with gradual deterioration and impacting patients for life. Two common progressive neurological disorders found in late life are Parkinson’s disease (PD) and motor neuron disease (MND). Psychological complications such as depression and anxiety are prevalent in people living with PD and MND, yet they are underdiagnosed and poorly treated. PD is classified a Movement Disorder and predominantly characterized by motor symptoms such as tremor, bradykinesia, gait problems and postural instability; however, neuropsychiatric complications such as anxiety and depression are common and contribute poorly to quality of life, even more so than motor disability. The average prevalence of depression in PD suggest 35% and anxiety in PD reports 31%. Depression and anxiety often coexist. Symptoms of depression and anxiety overlap with symptoms of PD, making it difficult to recognize. In PD, daily fluctuations in anxiety and mood disturbances are observed with clear synchronized relationships to wearing off of PD medication in some individuals. Such unique characteristics must be addressed when treating PD depression and anxiety. There is an increase in the evidence base for psychotherapeutic approaches such as cognitive behavior therapy to treat depression and anxiety in PD. Motor neuron disease (MND) is classified a neuromuscular disease and is characterized by progressive degeneration of upper and lower motor neurons is the primary characteristic of MND. The most common form of MND is Amyotrophic lateral sclerosis (ALS) and the terms ALS and MND are simultaneously used in the literature. Given the short life expectancy (average 4 years), rapid deterioration, paralysis, nonmotor dysfunctions, and resulting incapacity, psychological factors clearly play a major role in MND. Depression and suicide are common psychological concerns in persons with MND. While there is an ALS-specific instrument to assess depression, evaluation of anxiety is poorly studied; although emerging studies suggesting that anxiety is highly prevalent in MND. Unfortunately, there is no substantial evidence-base for the treatment of anxiety and depression in MND. Caregivers play a major role in the management of progressive neurological diseases. Therefore, evaluating caregiver burden and caregiver psychological health are essential to improve quality of care provided to the patient, as well as to improve quality of life for carers. In progressive neurological diseases, caregiving is often provided by family members and spouses, with professional care at advanced disease. Psychological interventions for PD carers addressing unique characteristics of PD and care needs is required. Heterogeneous clinical features, rapid functional decline, and short trajectory of MND suggest a multidisciplinary framework of carer services including psychological interventions to mitigate MND. A Supportive Care Needs Framework has been recently proposed encompassing practical, informational, social, psychological, physical, emotional, and spiritual needs of both MND patients and carers.
Nadeeka N. Dissanayaka
Anthony Randal McIntosh
Brain organization can be measured across multiple spatial and temporal scales where each scale affects the other in the emergent functions that are known as cognition. As a complex adaptive system, the interplay of these scales in the brain represents the information that ultimately supports what one thinks and does. The dynamics of these multiscale operations can be quantified with measures of complexity, which are sensitive to the balance between information that is coded in local cell populations and that is captured in the network interactions between populations. This local versus global balance has its foundation in the structural connectivity of the brain, which is then realized through the dynamics of cell populations and their ensuing interactions with other populations. Considering brain function and cognition in this way enables a different perspective on the changes in cognitive function in aging. Changes in brain signal complexity from childhood to adulthood were assessed in two independent studies. Both showed that maturation is accompanied by an overall increase in signal complexity, which also correlated with more stable and accurate cognitive performance. There was some suggestion that the maximal change occurs in medial posterior cortical areas, which have been considered “network hubs” of the brain. In extending to the study of healthy aging, a scale-dependent change in brain complexity was observed across three independent studies. Healthy aging brings a shift in local and global balance, where more information is coded in local dynamics and less in global interactions. This balance is associated with better cognitive performance and, interestingly, in a more active lifestyle. It also seems that the lack of this shift in local and global balance is predictive of worse cognitive performance and potentially predictive of additional decline indicative of dementia.