[16:47, 12/04/2021] Anindya Da: World Parkinson’s Day is celebrated each year on april 11 in the honour of James Parkinson, a great neurologist, researcher and activist, who was born on this date in the year 1755. He described the cardinal features of Parkinson’s disease (PD) in his famous write up “an essay on shaking palsy” in the year 1817. Later on, Dr. Jean-Martin Charcot named this disease after James Parkinson, calling it “Maladie de Parkinson” (Parkinson’s disease) as a gesture of acknowledgement and respect. April is celebrated as parkinsons awareness month where in doctors, nurses, physiotherapists, speech therapists, behavioural therapists, occupational therapists, support groups, many government and non government organizations worldwide come together in creating positivity and hope in the life of patients with PD. This year, the theme is, “unite for Parkinsons”, a call to action that urges people to stand for patients suffering from Parkinson’s and their loved ones and to help them in all possible ways. The idea is to spread the word and engage people and organizations in making life of patients with Parkinson disease easy and society more responsive towards them.
There are nearly ten million people living with Parkinsons disease worldwide, men being 1.5 times more affected than women. The incidence and prevalence increases with advancing age, around 1% of people above 65 years of age being affected from PD. There is no homogeneous and large epidemiological data available from India, however, sectoral data suggest a crude prevalence rate of 14.1 per 100,000 population in nothern India (Kashmir), 27 per 100,000 in southern part of India (Bangalore), 16.1 per 100,000 in eastern India (rural Bengal), and 328.3 per 100,000 among a population of 14,010 Parsis living in colonies in Mumbai, western India.
Parkinson’s disease is a chronic progressive neurodegenerative disorder characterized by early prominent loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) and wide spread presence of alpha synuclein (aSyn), an intracellular protein. Dopamine deficiency in the basal ganglia leads to the classical Parkinsonian motor symptoms viz, bradykinesia, tremor, rigidity and later postural instability. PD is also associated with non-motor symptoms viz, sleep disorders, hyposmia, autonomic dysfunctions, cognitive impairment, mood disorders and pain, which may precede motor symptoms by more than a decade. These non-motor symptoms become troublesome symptoms in the later stages of PD. Currently, the mainstay of PD management is pharmacological therapy, which include levodopa/ carbidopa, dopamine agonists (both ergot and non-ergot types), monoamine oxidase-B (MAO-B) inhibitors, injectable dopamine agonist (apomorphine), catechol-O-methyltransferase (COMT) inhibitors, N-methyl-D-aspartate (NMDA) receptor inhibitors, and anti-cholinergics. Dopaminergic therapy is highly effective in bradykinesia and rigidity but monoamine MAO B inhibitors are only moderately effective. Dopamine agonists and levodopa help to reduce disease progression and disability to an extent. Tremor responds to anticholinergic drugs like trihexyphenidyl but has a poor and inconsistent response to dopamine replacement therapy. However, these symptomatic therapies have major limitations in advanced disease. Many disabling features develop later in the course of the disease including non-motor symptoms, dopamine resistant motor symptoms and motor complications of long-term dopamine therapy. In the later stages of PD, drug delivery can be supplemented via alternative routes (e.g., intrajejunal infusions, subcutaneous injections or transdermal patches). Continued motor fluctuations and dyskinesias may be indications to evaluate the patient’s candidacy for deep brain stimulation (DBS). Although there have been remarkable advances in the medical and surgical treatment for PD, definitive disease modifying therapy is still eluding. However, researchers are hopeful that they will be able to identify the potential targets for disease modification in near future.
Non-pharmacological therapies viz, exercise, education, support groups, speech therapy and nutrition, are equally important and play a great role, if started early on in the disease course, in retarding the progression of disease and improving the quality of life of PD patients.
In the prevailing Covid-19 situation, patients with parkinsons disease are at higher risk because, they are usually aged population with waning immunity. Respiratory muscle rigidity as well as poor respiratory excursion makes them further vulnerable to ventilatory failure in the event of Covid-19 infection. Covid-19, like any other infection, could also lead to the worsening of parkinsonian motor symptoms like bradykinesia and or dyskinesias.
Therefore all precautions advised to avoid Covid-19 infection need to be followed by all PD patients, including social/physical distancing and 20-seconds hand washing. In severely affected patients needing ventilatory support, non-oral dopamine replacement strategy should be resorted to eg., liquid levodopa (via nasogatric tube or PEG), transdermal rotigotine patches, or apomorphine injection/infusion. Non motor symptoms especially; anxiety, depression and fatigue must also be enquired about and properly addressed. Drug – drug interactions especially, patients on MAO-B inhibitors with cough- cold remedies should be borne in mind while prescribing. Other drugs being tested and tried against Covid-19 viz., lopinavir, ritonavir, remdesevir, tociizumab, hydroxychloroquine etc have not shown any significant interaction with PD drugs, so far. Further, Amntadine, which is an ativiral agent used for PD, needs to be evaluated for its potential anti-Covid-19 effect. Hence amidst Covid-19, care for PD patients warrants further attention.
“While there are many diseases, there is, in a sense, only one health”. Park’s Text Book of PSM