What is Dementia?
Dementia is the general term used to describe a set of symptoms exhibited in individuals. The typical symptoms are difficulties with memory, language, and thinking. This impairment is a progressive decline in cognitive and behavioural functioning, meaning that it gets worse with time. The number of older individuals with Dementia is on the rise, with more than 50 million people in 2021, a number which is expected to triple by 2050 (Porsteinsson et al., 2021).
Alzheimer’s Disease vs Frontotemporal Degeneration
There are multiple causes of Dementia with two of the more common ones being Alzheimer’s Disease and Frontotemporal Degeneration. Alzheimer’s Disease is a degenerative disease typically seen within adults aged 65 or older, however there can also be an early onset, occurring in those under the age of 65 (Sá et al., 2012). Although the exact cause of Alzheimer’s Disease is not known, it is believed that a peptide, Amyloid-β, forms plaques outside of neurons and ultimately leads to neurodegeneration, mediated by the neurofibrillary tangles of a protein, Tau (Lesné et al., 2013).
In the earlier stages, with a milder cognitive impairment, patients with Alzheimer’s Disease may have trouble with episodic and short-term memory such as remembering recent conversations, executive function during familiar tasks, and with visuospatial tasks (Porsteinsson et al., 2021). As the disease progresses, there can be severe issues with cognition and behaviour, impacting social functioning and this is typically when assistance will be required to support a person’s daily life (Porsteinsson et al., 2021).
Frontotemporal Dementia has its onset around the ages of 45-65; however, symptoms can also appear earlier or later than this age range (Bang et al., 2015). It is a heritable disorder, with a third of patients reporting an autosomal dominant family history (Rohrer et al., 2015). This type of Dementia is characterized by progressive degeneration within the frontotemporal neural networks (Boeve et al., 2022). Many Frontotemporal Dementia patients show the presence of Tau and a transactive response DNA-binding protein in their brains, indicating their potential implications in the degeneration which occurs (Bang et al., 2015).
Those with Frontotemporal Dementia can experience impairments in social cognition and behaviour as well as apathy, trouble with language, and changes in personality (Boeve et al., 2022). In contrast to Alzheimer’s disease, memory is not as affected within these early stages. In the end-stage, patients may experience trouble eating, swallowing, and moving (Bang et al., 2015).
When a neuropsychological assessment can be helpful
One common aspect of aging, even in those without Dementia, is the gradual decline in cognitive processes, such as memory and processing speed (Harada et al., 2013). Healthy adults can have trouble with source memory such as remembering the source of learned information, or prospective memory such as remembering to perform future actions like taking medicine (Harada et al., 2013). Although these changes are common in older adults, if there are changes in thinking, memory, or behaviour that concern you, a neuropsychological assessment or screening can be completed to further explore these challenges. Although a timely diagnosis of Dementia maximizes the benefits of receiving treatment, it can be challenging within the early stages to distinguish between symptoms of normal aging and cognitive impairment seen in Dementia (Salloway & Correia, 2009). It is often that Dementia is not diagnosed until late in the disease process.
In those with suspected Dementia, a neuropsychological assessment is an important diagnostic element in addition to examining patient history, or further, an examination of brain structures through Magnetic Resonance Imaging (MRI) (Reul et al., 2017). It has been found that diagnoses made based on the cognitive profiles of patients who underwent testing, were supported by later brain scans and biomarker evidence of the disease progression (Reul et al., 2017). A neuropsychologist can help the individual and family understand how the person’s scores on cognitive tests compare to others their age and make recommendations with respect to additional treatment and referrals.
References
Bang, J., Spina, S., & Miller, B. L. (2015). Frontotemporal dementia. The Lancet, 386(10004), 1672-1682. https://doi.org/10.1016/S0140-6736(15)00461-4
Boeve, B. F., Boxer, A. L., Kumfor, F., Pijnenburg, Y., & Rohrer, J. D. (2022). Advances and controversies in frontotemporal dementia: Diagnosis, biomarkers, and therapeutic considerations. The Lancet Neurology, 21(3), 258–272. https://doi.org/10.1016/s1474-4422(21)00341-0
Harada, C. N., Natelson Love, M. C., & Triebel, K. L. (2013). Normal cognitive aging. Clinics in Geriatric Medicine, 29(4), 737–752. https://doi.org/10.1016/j.cger.2013.07.002
Lesné, S. E., Sherman, M. A., Grant, M., Kuskowski, M., Schneider, J. A., Bennett, D. A., & Ashe, K. H. (2013). Brain amyloid-β oligomers in ageing and alzheimer’s disease. Brain, 136(5), 1383–1398. https://doi.org/10.1093/brain/awt062
Porsteinsson, A. P., Isaacson, R. S., Knox, S., Sabbagh, M. N., & Rubino, I. (2021). Diagnosis of Early Alzheimer's Disease: Clinical Practice in 2021. The journal of prevention of Alzheimer's disease, 8(3), 371–386. https://doi.org/10.14283/jpad.2021.23
Reul, S., Lohmann, H., Wiendl, H., Duning, T., & Johnen, A. (2017). Can cognitive assessment really discriminate early stages of Alzheimer’s and behavioural variant frontotemporal dementia at initial clinical presentation? Alzheimer’s Research & Therapy, 9(1). https://doi.org/10.1186/s13195-017-0287-1
Rohrer, J. D., Nicholas, J. M., Cash, D. M., van Swieten, J., Dopper, E., Jiskoot, L., van Minkelen, R., Rombouts, S. A., Cardoso, M. J., Clegg, S., Espak, M., Mead, S., Thomas, D. L., De Vita, E., Masellis, M., Black, S. E., Freedman, M., Keren, R., MacIntosh, B. J., … Rossor, M. N. (2015). Presymptomatic cognitive and neuroanatomical changes in genetic frontotemporal dementia in the genetic frontotemporal dementia initiative (GENFI) study: A cross-sectional analysis. The Lancet Neurology, 14(3), 253–262. https://doi.org/10.1016/s1474-4422(14)70324-2
Salloway, S., & Correia, S. (2009). Alzheimer’s disease: Time to improve its diagnosis and treatment. Cleveland Clinic Journal of Medicine, 76(1), 49–58. https://doi.org/10.3949/ccjm.76a.072178
Sá, F., Pinto, P., Cunha, C., Lemos, R., Letra, L., Simões, M., & Santana, I. (2012). Differences between early and late-onset Alzheimer’s disease in neuropsychological tests. Frontiers in Neurology, 3. https://doi.org/10.3389/fneur.2012.00081
Author: Andrea Nizic, Undergraduate Student at Wilfrid Laurier University Majoring in Psychology and Neuroscience
Comments