Parkinson’s disease (PD) is a chronic neurodegenerative brain disorder.It was first described by Dr. James Parkinson in 1817 as a “shaking palsy.” It occurs when certain nerve cells in a part of the brain called the substantia nigra die or become impaired. When approximately 80 percent of neurons are damaged, the symptoms of Parkinson’s disease appear. The risk of developing Parkinson’s disease increases with age. In a review , it was reported that an estimated 10 million people in the world (i.e., approximately 0.3% of the world population) and 1% of those above 60 years are found to be affected with PD.The disease has a significant clinical impact on patients, families, and caregivers.
It is characterized by both motor and non motor features. The motor symptoms of PD are attributed to the loss of striatal dopaminergic neurons, although the presence of nonmotor symptoms supports neuronal loss in nondopaminergic areas as well. Not only motor symptoms but also non motor symptoms increase in their severity and burden over time, increasing patients’ disability, with additional worsening of their quality of life, as well as caregivers’ burden and consequential consumption of social resources by increasing societal costs. That is why, it would be necessary to identify motor with nonmotor symptoms.
Cardinal Motor Symptoms (“Classical Triad”)
- Bradykinesia (80% to 90% of patients): Slowness of movement.
- Rigidity (80% to 90% of patients): Resistance to passive movement.
- Tremor at rest (70% to 90% of patients): Common initial symptom, primarily involving hands, often resolves with action or during sleep, may also involve jaw, tongue, lips, chin, or legs
- Postural instability: Occurs in later stages of Parkinson’s disease & results from loss of postural reflexes. Predisposes patients to falls and injuries.
- Dysarthria (difficulty in speech as slurring)
- Dystonia (abnormal body posture or movement)
- Difficulty with handwriting (e.g., micrographia) and soft speech (hypophonia)
Non-motor Symptoms of Parkinson’s Disease
- Autonomic Dysfunction: Constipation, Orthostatic hypotension (Drop in blood pressure while standing), Urinary retention, increased urinary frequency & urgency & Sexual dysfunction…….
- Neuropsychiatric Symptoms: Anxiety, Cognitive impairment (mild), Dementia, Depression (e.g., dysphoria, suicidal ideation, apathy), Impulse-control disorders (e.g., preoccupations, hypersexuality, compulsive shopping, binge eating), Panic disorder & Psychosis (e.g., hallucinations, delusions)
- Sensory Symptoms: Olfactory dysfunction (hyposmia-decreased smell sense), Paresthesias, Pain body & limbs
- Sleep Disturbances: Daytime somnolence, Insomnia, Rapid eye movement disorder, Restless legs syndrome, Sleep attacks. & Sleep apnea
- Others: Fatigue, Sialorrhea (excessive salivation) & Weight loss
The term parkinsonism is a symptom complex used to describe the motor features of Parkinson disease, which include resting tremor, bradykinesia, and muscular rigidity. Parkinson disease is the most common cause of parkinsonism, although a number of secondary causes also exist, including diseases that mimic PD and drug-induced causes.
Atypical Parkinsonism or Parkinson Plus
- Multiple system atrophy (MSA): Like Parkinson’s, MSA can cause stiffness and slowness of movement in the early stages. However, people with MSA can also develop symptoms that are unusual in early Parkinson’s, such as unsteadiness, falls, bladder problems and dizziness.
- Progressive supranuclear palsy (PSP): PSP affects eye movement, balance, mobility, speech and swallowing.
- Corticobasal ganglionic degeneration
Vascular parkinsonism (also known as arteriosclerotic parkinsonism) affects people with restricted blood supply to the brain. Sometimes people who have had a mild stroke may develop this form of parkinsonism. Common symptoms include problems with memory, sleep, mood and movement.
Normal pressure hydrocephalus (NPH)
Normal pressure hydrocephalus mainly affects the lower half of the body. The common symptoms are walking difficulties, urinary incontinence and memory problems. Removing some cerebrospinal fluid through a needle in the lower back can help with these symptoms in the short term. If there is improvement after this procedure, an operation to divert the spinal fluid permanently (known as ventricular drainage) can help in the long term.
Some drugs can cause parkinsonism. Neuroleptic drugs (used to treat schizophrenia and other psychotic disorders), which block the action of the chemical dopamine in the brain, are thought to be the biggest cause of drug-induced parkinsonism. Most will recover within months –and often within days or weeks – of stopping the drug that’s causing it.
Rarer causes of parkinsonism
There are several other, much rarer, possible causes of parkinsonism.These include rare conditions like Wilson’s disease, Huntington’ disease, Multi-infarct state, Infection (AIDS, Prion disease), Recurrent head trauma & toxins (carbon monoxide, manganese, mercury, methanol, ethanol).
Various tremors, including essential tremor While these are not parkinsonian disorders, you may be diagnosed with one of these conditions if tremor is your only symptom.
You should need a Parkinson’s specialist for diagnosis. Diagnosis is mainly clinical depending upon the expertise of your physician. It requires magnetic resonance imaging (MRI) brain scanning & dopamine transporter chemical scan (DaTScan).
In many cases, parkinsonism develops gradually. Symptoms that allow your doctor to make a specific diagnosis may only appear as your condition progresses. Everyone with parkinsonism is different and has different symptoms.
A group of drugs are available to maintain the dopamine level in the brain. Which may delayed the disease process & symptomatic improvement.
Depending upon the type of parkinsonism, patient age, general condition, response to medication & other associated co-morbidities, deep brain stimulation (DBS) surgery is also available. DBS is just like pacemaker to brain to control various motor symptoms in parkinson’s disease.
Your specialist will be able to tell you more.