Deep Brain Stimulation As A Treatment for Neurodegenerative Diseases

 by Henry Hayter


X ray of deep brain stimulation

Parkinson’s is a neurodegenerative disease that is caused by the degeneration of [1]dopaminergic neurons in the Substantia nigra region of the brain ( the region which is responsible for the facilitation of movement and large amounts of dopamine production) which results in a number of symptoms which tend to develop over a long period of time (usually several years) , the symptoms of Parkinson’s include : Limb rigidity, Bradykinesia or slow limb movement and tremors, loss of balance and gait/posture, the severity of these symptoms is measured on the modified 2Hoehn and Yahr Scale . The scale is from 1 to 5 with 1 containing the least debilitating symptoms such as bradykinesia in unilateral movement only and 5 containing the most debilitating symptoms which have left the patient wheelchair or bed bound by the disease . Parkinson’s disease is currently without a permanent cure although treatments such as L-Dopa therapy and physiotherapy do delay the development of more severe symptoms. DBS is another temporary cure for parkinson’s disease as can work effectively for upwards of 10 years although the process of DBS is invasive and as such is often reserved for more severe cases of Parkinson’s disease, furthermore given that the average parkinson’s patient is in their late 50s or mid 60s it is more risky to undergo a surgery due to the increased likelihood of comorbidities affecting the patient’s overall health.

Deep Brain Stimulation or DBS is a surgical procedure in which electrodes are inserted into a targeted region of the brain ,often the subthalamic nucleus (STN) and the globus pallidus interna (GPi). The electrodes are inserted via an MRI in the first of two procedures. During the second procedure an Impulse generator battery is placed below the clavicle and connected to the electrodes via a lead. The generator provides impulses to the electrodes interfering the impulses sent from the degenerating region of the brain preventing the symptoms of Parkinson’s disease from manifesting. As a result the DBS treatment is the most effective treatment for Parkinson's where other treatments have failed to effectively halt the disease's progression.

The relative newness of DBS as a treatment of PD being only 24 years old has meant that the long term effects of the treatment on the patient is yet to be fully understood. A survey was carried out in 2017 finding that 51% of patients of DBS were alive 10 years later , the survey also found that of the patients who responded 90% were satisfied with the alleviation of symptoms that the treatment had provided and that 75% of those who received the DBS thought that their symptoms had improved noticeably since receiving the treatment.

Given the lack of alternative long term treatments that many patients who undergo DBS have available to them - it should be noted that while DBS is often used alongside chemical and physiotherapy techniques including the L-Dopa therapy mentioned before, DBS has been shown to provide the greatest amount of symptom relief over the longest period of time and therefore is a popular treatment for those who suffer from Parkinson’s and whose chemical therapy and physiotherapy is failing to alleviate all of the symptoms of the disease fully .

Sources,

https://www.parkinson.org/

https://www.physio-pedia.com/images/5/52/PPHYscaleParkinsons.pdf

https://bit.ly/3ujbnGe



[1] Neurons which are responsible for dopamine production

2  The scale used to determine the impact of Parkinson’s on the patient and how likely they are to need to seek further treatment, full scale can be seen at: https://www.physio-pedia.com/images/5/52/PPHYscaleParkinsons.pdf


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