What is Parkinson’s disease?
Parkinson’s disease is a chronic condition due to progressive neuronal degeneration with the initial appearance of motor deficits followed by non-motor deficits of the sensory, cognitive and behavioral types.
Why does Parkinson’s disease occur?
Parkinson’s disease-specific motor deficits are caused by cellular losses of the substantia nigra located in the midbrain region, leading to decreased levels of dopamine in the body. The exact cause of these neuronal losses is not known, but it is suspected that there is a link between PD and the accumulation of alpha-synuclein aggregates (alpha-synuclein aggregates) with a cytotoxic effect in the brain, in the form of Lewy bodies that alter the activity of nerve cells, leading to motor disorders.
The main risk factors for Parkinson’s disease are:
- Age: the condition occurs mainly in people over 60
- Gender: males are more likely to develop PD
- Low dopamine levels favor the onset of the disease
- Repeated, long-term exposure to toxic substances – manganese, carbon disulfide
- Family history: people who have at least 1 relative with this condition in their family are at risk of developing Parkinson’s disease
What are the symptoms of Parkinson’s disease?
Symptoms of Parkinson’s disease are insidious and are often overlooked until they worsen in the advanced stages of the disease. The classic motor deficits for this disease are: tremors of the extremities, bradykinesia (slowed movements), muscle rigidity (increased muscle tone associated with involuntary continuous contractions) and postural instability. Non-motor symptoms become evident later and may be represented by neuropsychiatric disorders (changes in mood – depression, apathy, anxiety and behavior or thinking), altered sense of smell and the appearance of altered sleep quality.
Partial or total loss of reflexes (blinking), alteration of the ability to express oneself with the appearance of slow and sometimes blurred speech, changes in handwriting or the presence of visual hallucinations and paranoid ideas are other symptoms that complete the clinical picture of patients with BP.
Parkinson’s disease staging is based on the patient’s symptoms and includes:
- Stage I is manifested by the appearance of a mild distal tremor that does not affect the patient’s daily activities, a change of posture with the adoption of an unconventional position and difficulty walking
- Stage II is recognized by the appearance of generalized muscle stiffness (affecting limbs on both sides of the body)
- Stage III is accompanied by loss of balance and bradykinesia which prevents the patient from performing activities such as dressing or washing
- Stage IV is defined by worsening symptoms with the appearance of continuous distal tremors, pronounced postural imbalance and speech difficulties
- Stage IV is manifested by the appearance of intense generalized muscle rigidity making it impossible for the patient to move
Diagnosis of Parkinson’s disease
The diagnosis of Parkinson’s disease is determined by the neurologist based on the patient’s history, and physical and neurological examination. The recommended imaging investigations for the diagnosis of PD are:
- Positron Emission Tomography PET CT to identify brain lesions causing dopamine deficiency
- Single photon emission CT can rule out other pathologies that evolve with the onset of essential tremor
- Diffusion nuclear magnetic resonance can differentiate dementia with Lewy bodies from other pathologies with similar symptoms
Treatment of Parkinson’s disease
Treatment of dementia with Lewy bodies is currently used to reduce the intensity of symptoms and improve the quality of life of Parkinson’s patients through:
- Drug treatment with Levodopa and COMT Catechol-O-methyltransferase inhibitors (a substance that degrades levodopa before it crosses the blood-brain barrier to perform its functions), Dopamine agonists
- Deep brain stimulation DBS – surgical method of stimulating brain activity involving the insertion of electrodes into specific brain regions via DBS surgeries
- Constant exercise, healthy eating and maintaining a regular rest program are beneficial for improving flexibility and improving mood changes in BP patients
Find out more:
- Parkinson’s disease – https://www.nature.com/articles/nrdp201713
- Parkinson’s disease – https://onlinelibrary.wiley.com/doi/abs/10.1111/ene.14108
- Diagnostic Criteria for Parkinson’s Disease – https://jamanetwork.com/journals/jamaneurology/article-abstract/774675
