Journal of Multiple Sclerosis

A Potential Clinical Index for Parkinson's Disease Using Human Brain Magnetic Resonance Imaging

Adam Hoffman^{* *}Correspondence: Adam Hoffman, Department of Medicine, University of Florida, United States, Email:

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Introduction

The telencephalon, diencephalon, midbrain, pons, medulla oblongata, cerebellum, and basal ganglia are the anatomical divisions of the brain. Each component performs a certain role. The striatum, globus pallidus, subthalamic nucleus, and substantia nigra are the specific components of the basal ganglia and are involved in processes including voluntary movement, eye movements, learning, and memory [1]. The putamen is the region of the striatum that carries out a variety of tasks, including memory, motivation, language processing, motor control, and emotion regulation. Although the putamen directly receives information from the ipsilateral hemisphere, little is known about its functional characteristics. In patients with heart failure and obstructive sleep apnea syndrome, Kumar et al. assessed the putamen's function by linking changes in the dorsal and ventral putamen's volume to motor dysfunction in the oral and upper airway regions. In two earlier studies, Künzle [2-3] demonstrated that the motor and somatosensory cortical areas in the upper and lower limbs and trunk, respectively, differentiate where each projection is sent. Künzle also demonstrated that the putamen receives projections from the motor and somatosensory areas for that function. The connection between the putamen's function and localization has been noted in numerous previous investigations. However, it is believed that the putamen largely plays a role in emotional and motor regulation, and its functional localization is still not entirely known. Numerous patients with putaminal bleeding have been seen in our clinical practise, which raises the possibility that physical activity and the location of putamen injury are related. We believe that the putamen has a functional localization, just as other brain structures and nuclei (such as the thalamus). Putaminal degeneration is a known symptom of Parkinson's Disease (PD). Progressive neurodegenerative illnesses, including Parkinson's Disease (PD), have a high death rate once they manifest, frequently result in impairment, and are followed by a loss of independence. According to Wirdefeldt et al., PD incidence is 14–19 per 100,000 cases annually, and prevalence is thought to be 100–300 per 100,000 cases. PD is the neurodegenerative disease with the fastest increasing prevalence, disability, and mortality, according to the 2017 Global Burden of Disease, Injuries, and Risk Factors Study, which also noted that the overall number of people with the condition had more than doubled since 1990. The GBD Parkinson's Disease Collaborators (2018) state that environmental factors, ageing, greater life expectancy, and declining smoking rates all contribute to the rising prevalence of PD [4]. A rise in the incidence and prevalence of PD was brought on by an increase in the number of older persons due to higher life expectancy across the majority of nations and regions as a result of the advancement of economic and medical standards. Dopaminergic neuron loss in the substantia nigra pars compacta, dopamine insufficiency in the striatum, and Lewy body buildup are the hallmarks of Parkinson's Disease (PD). Additionally, it is linked to abnormalities of motor function such tremors, stiffness, and akinesia. These symptoms are brought on by aberrant inhibition and hyperexcitability in the globus pallidus, thalamus, subthalamic nucleus, and basal ganglia as a result of substantia nigra pars compacta degeneration. Pharmacotherapy, physical therapy, and functional neurosurgery treatments on the thalamus, subthalamic nucleus, and globus pallidus are frequently used to treat Parkinson's Disease (PD). Although the globus pallidus and subthalamic nucleus have gotten the most attention in PD, Santos et al. found that putamen volumes were lower in people with PD and Parkinson's syndrome compared to healthy people [5]. The putamen's atrophy may be a key sign of the beginning of Parkinson's disease symptoms like freezing and shortstepped gait. Therefore, the purpose of this work was to develop an assessment technique for putamen atrophy that could be used in clinical settings and to demonstrate how it related to PD-related changes in physical function. The clinical diagnosis of PD is made based on symptoms because it is a progressive degenerative illness that is challenging to detect. On the basis of those disclosed by the British Brain Bank, numerous diagnostic criteria have been established, and numerous clinical trials have been carried out. The British Brain Bank's diagnostic standards call for patients to exhibit bradykinesia and to rule out other disorders as much as feasible. Additionally, one of the fundamental PD diagnostic criteria is the existence of some retentive support variables. Since then, various testing techniques have been developed by physicians and academics in an effort to create diagnostic criteria for PD. The International Parkinson and Movement Disorder Society have also suggested revised diagnostic standards. As a result, we concentrated on putamen volume. Three-dimensional pictures were employed in a prior work to examine volume changes [6]. However, two-dimensional images from radiography, computed tomography, and Magnetic Resonance Imaging (MRI) are frequently employed in emergency hospitals that don't have time for first consultations and clinics that treat outpatients. Three-dimensional images are primarily used in research. So, based on MR scans, we suggest a straightforward and incredibly precise indicator of putamen atrophy that may be applied in clinical settings. Based on this recently proposed criterion, we compared patients with and without Parkinson's disease.

 

Discussion

Overview

The goal of this study was to develop and evaluate a method for using MRI to assess putamen atrophy as well as determine whether the putamen change ratio correlates with PD alterations. Our findings demonstrated that this evaluation technique had a modest intra-examiner measurement error and adequate intra-observer reliability. Additionally, the putamen's change ratio varied significantly between the PD and control groups, indicating that it is consistent with the PD diagnosis.

A Technique for Assessing Putamen Atrophy

In this study, we proposed to assess putamen atrophy using a change ratio derived from MR images. A satisfactory intra-rater reliability of 0.842 was shown by the ICC. MRI currently enables the analysis of threedimensional brain images using techniques like MRIcron and generalised auto-calibrating partially parallel acquisitions [7]. Because image processing takes more time, three-dimensional images aren't currently frequently employed in emergency rooms and first medical exams. Two-dimensional images, in contrast, are frequently utilised in therapeutic settings since they take less time and place less of a load on the patient. As a result, they provide important benefits during the initial examination. Any medical practitioner working in the field can evaluate the evaluation procedure described here because it is straightforward. Three-dimensional images are also time-consuming to examine and are commonly employed in research. As it can be done from an MRI and utilised as a parameter for screening and diagnosing PD, this evaluation method is quick and easy. Additionally, while there are sporadic instances of putamen volume changes in PD, there are no reports of thalamus volume changes. As a result, the putamen change ratio for that in the thalamus was calculated [8]. Clear diagnostic imaging techniques are required, as there has been considerable discussion on intra- and inter-examiner mistakes for some time. Image discrimination is influenced by the reader's experience as assessments are made by visually evaluating the posterior limb of the internal capsule, thalamus, and putamen. The ICC in this instance, however, was >0.7 and demonstrated reproducibility with a minor mistake for the same examiner. The findings of evaluations conducted by the same examiner on different days will not alter, making their use extremely important. Despite the fact that individual variations may influence putamen measurements, physicians can account for any mistakes by comparing the ratio to the thalamus distance. Numerous areas of the capsule experience atrophy, and it is difficult to capture changes in three dimensions in two dimensions. The outcomes of the proposed evaluation approach for this study, however, revealed important variations between the two groups. We think that the approach effectively captures changes in the nucleus's location brought on by variations in its exterior form and atrophy. Therefore, analysing the putamen's change ratio could detect volumetric changes or exterior forms.

Ratio Variation in Both Groups' Putamen

Between the PD and control groups, there was a discernible difference in the putamen's change ratio (p = 0.015). Our findings point to a difference in the putamen's change ratio between patients with and without Parkinson's Disease (PD), which may be a sign of putamen atrophy. The putamen may undergo alterations as a result of PD [9]. It's crucial to remember that putamen atrophy can also be brought on by ageing. Global and regional grey matter volume decreases with age in healthy adults, according to structural neuroimaging studies using a longitudinal methodology. In 66 healthy older people between the ages of 60 and 84, Thambisetty evaluated longitudinal changes in cortical thickness. The study demonstrated extensive age-related loss in cortical thickness, with frontal and parietal regions along an anteriorposterior gradient showing higher rates of decline than temporal and occipital regions. In this investigation, there were no discernible differences between the two patient groups. The 5-year gap and level of age-related atrophy are still up for debate because prior research frequently studied those decades apart. Even though there was no discernible difference, a closer examination of the left-right difference revealed that the left side had changed more. The left side is primarily damaged, according to these data, which are in line with earlier research' findings [10]. A control group was made up of patients who had TIA or lacunar infarction. The control group started using MRI images 30 minutes after the initiation. At 18 months following a TIA, Muhammad et al. found no significant difference between TIA participants and normal participants in age-related brain shrinkage. As a result, lesion-induced brain shrinkage is not anticipated to have an impact on the MRIs used in this investigation because they were acquired within 30 minutes of the TIA's commencement. We also used images from the side of the lacunar infarct that was not compromised by the lesion and that we did not anticipate would be impacted by brain atrophy. Healthy people do not experience Parkinson's Disease (PD) or multiple system atrophy, thus putamen atrophy that is more rapid than that caused by age may indicate the onset of movement abnormalities including frozen gait and brachybasia. Therefore, employing the putamen's change ratio as a marker for Parkinson's disease may lower the risk of contracting the illness. Additionally, involving patients in early intervention may prolong healthy life expectancy and stop PDrelated decrease in activities of daily living and quality of life.

Limitations

This research had several restrictions. First, because the MR pictures used in this study were obtained at the same institution using the same imaging methodology, the image processing accuracy of the evaluated images was comparable. It is yet to be determined how different imaging protocols or pieces of equipment affect the accuracy of picture assessment. Therefore, it will be required in the future to compare the outcomes utilising MR images taken under various circumstances. Furthermore, 3D imaging should be used to verify volume changes. Using 3D imaging, different brain volumetric measurements can be made, each with unique properties. Before 3D images may be used in clinical practise, there are still several challenges that need to be worked out in study. The MRI employed in this evaluation method, which may also be used as a diagnostic parameter, makes it straightforward. Based on these considerations, a future issue is to contrast and evaluate the ratio values computed using the putamen and thalamus volumes obtained using 3D pictures with the outcomes of this study obtained using 2D images. Second, the evaluations were conducted using the locations of the internal capsule, putamen, and thalamus on MR images. For such evaluations to discriminate between the internal capsule, putamen, and thalamus, a high level of reader experience and high-quality images are needed. These measurements accurately assess the putamen's lentiform nucleus and the globus pallidus. The volume reduction in the globus pallidus, which receives less dopaminergic input than the striatum, should be minimal, according to Matochik et al.. Although there is certainly room for improvement, we chose this approach because we hypothesised that it would enable us to evaluate the putamen by looking at changes in the lentiform nucleus. As a result of the small patient sample and probable putamen atrophy, we concentrated on patients with PD. Putamen degeneration is a condition linked to multiple system atrophy. Parkinsonism is a common sign of putamen degeneration, which is the primary cause of striatonigral degeneration. By evaluating the evaluation process, expanding the number of cases, and figuring out the threshold rate of change in the putamen for PD, we want to increase the accuracy of this diagnostic marker. In the future, we would like to enhance the classification of patients in the PD group according to the length of treatment and severity of the disease, as well as the inclusion of patients with striatal substantia nigra degeneration to better understand the role of the putamen in this neurodegenerative condition.

Conclusion

Here, we suggested a technique for using MRI to assess putamen atrophy. Putamen atrophy may be indicated by the fact that the putamen change ratio was considerably lower in PD patients than in controls. By increasing the precision in measuring the putamen change ratio, this method may also be used for early identification of Parkinson's Disease (PD) and preventative treatment.

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