Parkinson’s disease is classified among movement disorders, but today we know it is far more than that. It is a chronic, progressive neurodegenerative disease which, in addition to altering motor control, can cause cognitive, emotional, sleep, autonomic and sensory symptoms.
Its impact is not limited to mobility; it can significantly affect independence and quality of life.
What happens in the brain?
The origin of Parkinson’s is related to the progressive death of dopaminergic neurons in the substantia nigra (pars compacta).
These neurons form part of the nigrostriatal pathway, key to regulating the basal ganglia and the fluidity of movement. The decrease in dopamine causes a loss of automatic coordination.
In addition, there is an accumulation of alpha-synuclein (Lewy bodies) and alterations in other neurotransmitters such as serotonin, noradrenaline and acetylcholine, which explains the non-motor symptoms.
Causes and risk factors
Parkinson’s is a multifactorial disease, influenced by:
- Genetic factors (LRRK2, GBA1, SNCA)
- Environmental factors (such as pesticides)
In most cases there is no single cause, but rather a combination of biological predisposition and environment.
Impact and prevalence
Parkinson’s is one of the fastest-growing neurological diseases:
- More than 8.5 million people affected worldwide
- Projection of 25.2 million by 2050
- In Spain: 200,000 people and 10,000 new cases a year
Diagnosis can be delayed by 1 to 3 years.
Motor symptoms
- Bradykinesia (slowness of movement)
- Reduction of automatic movement
- Resting tremor
- Muscle rigidity
- Postural instability and risk of falls
- Difficulty with fine motor skills
- Speech alterations
- Swallowing problems and sialorrhoea
Sialorrhoea is usually not due to excess saliva, but to a reduction in automatic swallowing.
Non-motor symptoms
They frequently appear even before the motor symptoms:
- Anxiety, depression and apathy
- Sleep disorders
- Fatigue
- Constipation and urinary problems
- Sexual dysfunction
- Loss of smell
- Pain and daytime sleepiness
Depression can be one of the first manifestations in up to 40% of cases.
Cognitive involvement
Parkinson’s can also affect:
- Attention
- Processing speed
- Working memory
- Executive functions
It is regarded as a clinical continuum, in which cognitive symptoms are part of the disease.
Who does it affect?
Age is the main risk factor:
- 2% of people over 65
- 4% of people over 80
- 15% of cases in people under 50
It is more frequent in men.
Diagnosis
Diagnosis is mainly clinical.
To speak of parkinsonism there must be: bradykinesia + resting tremor or rigidity.
There are complementary tests and biomarkers under development, but they do not replace clinical assessment.
Treatment
At present: there is no cure or treatment that halts progression.
But there are effective options for controlling symptoms:
- Levodopa (main treatment)
- Dopamine agonists
- MAO-B inhibitors
In advanced stages:
- Deep brain stimulation
- Continuous infusion therapies
Neurorehabilitation
Treatment is not only pharmacological. The approach must be multidisciplinary:
- Physiotherapy: gait and balance
- Occupational therapy: independence
- Speech and language therapy: speech and swallowing
This approach makes it possible to maintain function and independence for longer.
The future of Parkinson’s
Research is advancing in:
- More precise biomarkers
- Therapies targeting alpha-synuclein
- Disease-modifying treatments
Some therapies, such as prasinezumab, are in advanced stages of research.
Conclusion
Parkinson’s is a complex neurodegenerative disorder, with motor and non-motor symptoms, which requires:
- Early diagnosis
- Specialised follow-up
- A comprehensive approach
Although there is no cure, current advances make it possible to significantly improve the quality of life of people living with this disease.
