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Brain & Heart Practical tips for AD and PD

clinical, and pathogenic features. For instance, both Parkinson’s disease dementia (PD-D) is a significant
are age-related disorders and are more common in and challenging aspect of PD, affecting a substantial
individuals over the age of 65. At the cellular level in these portion of individuals with PD as the disease progresses.
diseases, neurodegenerative process occurs, leading to The prevalence of PD-D during the clinical course of PD
cell death, oxidative stress, excitotoxicity, senile plaques, varies between 28% and 44%. The time from the onset
nigral degeneration, and accumulation of cytoplasmic of early motor symptoms of PD, such as tremor and
inclusions. Furthermore, they share overlapping clinical rigidity, to the onset of cognitive impairment in PD-D is
characteristics, such as extrapyramidal features and associated with a complex and multifaceted mechanism .
[8]
[1]
dementia . PD-D typically starts with subtle changes in cognitive
AD, a progressive neurodegenerative disorder, poses function, often manifesting as mild memory difficulties
one of the most formidable challenges to aging populations and difficulties in multitasking or problem-solving. These
worldwide. It is the most common form of dementia and initial symptoms, however, foreshadow the intricate and
affects more than 25 million people worldwide. While it debilitating cognitive decline that characterizes PD-D.
generally affects 5% of individuals over the age of 65, this The underlying pathology of PD-D shares commonalities
rate rises to 25% in individuals over the age of 80 . It is with PD, involving the accumulation of abnormal protein
[2]
characterized by a subtle yet insidious onset, often marked aggregates, primarily alpha-synuclein, which leads to
by initial symptoms that primarily affect memory and neurodegeneration in critical brain regions, including
cognitive functions. These early signs, such as forgetfulness, the substantia nigra and cortex [9,10] . The epidemiology of
difficulty in finding words, and impaired problem-solving, PD-D reveals intriguing insights, including the fact that
represent the tip of the iceberg caused by the complex the risk of developing dementia in PD increases with
[11]
pathological cascade unfolding within the brains of the age, disease duration, and severity of motor symptoms .
patients. Neuropathologically, diffuse neuronal cell loss In addition, gender differences may play a role, as some
is accompanied by amyloid plaques and neurofibrillary studies suggest that men with PD have a slightly higher
[12]
tangles. AD is etiologically linked to the aggregation of risk of developing dementia compared with women . In
amyloid-beta plaques and tau protein tangles, which PD-D, MRI findings are also used to assist with diagnosis.
leads to synaptic dysfunction and neuronal loss . Loss In individuals with PD-D, MRI findings commonly reveal
[3]
of physical function will be added to these findings in the structural alterations within key brain regions involved
future. Definitive diagnosis of AD is only possible with in both motor and cognitive functions. Atrophy of the
postmortem neuropathological examination, but clinical substantia nigra, a hallmark of PD, can be visualized
diagnosis can be made with neuropsychological testing using MRI, highlighting the neurodegenerative process
and exclusion of other forms of dementia . Although that underlies the motor symptoms . Importantly, MRI
[13]
[4]
imaging approaches are utilized in the process of making studies of PD-D also unveil significant changes in cortical
diagnosis, specific findings for the disease cannot be and subcortical regions, including the frontal cortex
derived from the imaging studies at the onset of symptoms. and hippocampus, which are associated with cognitive
Magnetic resonance imaging (MRI) findings in AD reveal impairment . These MRI findings not only contribute
[14]
a distinctive pattern of structural brain changes in disease to the understanding of the structural underpinnings of
progression. These imaging studies commonly depict PD-D but also have clinical implications for early diagnosis
cerebral atrophy, especially in regions crucial for memory and disease progression monitoring.
and cognition, such as the hippocampus and the entorhinal Despite the differences between PD-D and AD in terms
cortex . Moreover, white matter hyperintensities, which of clinical, neuropathology, and neuroimaging findings,
[5]
are non-specific to AD, are an indication of vascular both pathological conditions share some similarities
damage often found in AD patients, further affecting their in different disease stages. While amnestic changes are
cognitive function . Beyond regional atrophy, functional more prominent in AD, more significant deterioration
[6]
MRI (fMRI) studies have illuminated alterations in brain in executive functions is observed in PD-D . We relied
[15]
connectivity and network integrity, shedding light on primarily on neuropsychological tests and neurological
the disruption of neural communication in AD . The
[7]
combination of structural and fMRI findings also advances examinations to diagnose pathological conditions in the
our understanding of the complex neural changes outpatient clinic. Unfortunately, more expensive tests such
underlying this devastating disorder. Understanding as fMRI or cerebrospinal fluid were not performed on
every patient.
both the initial symptoms and underlying pathology of
AD is crucial for early detection, accurate diagnosis, and In this study, we aimed to create a profile for the
management of this common and debilitating condition. diagnosis and clinical features of dementia by evaluating

Volume 2 Issue 1 (2024) 2 https://doi.org/10.36922/bh.1712