Parkinson's Disease: What It Is, Symptoms, and Forms

Parkinson's disease is a condition in which parts of the brain gradually become damaged over many years. It manifests primarily as slowed movements, muscle stiffness, and tremor, but it also affects sleep, mood, and sense of smell. Below are the mechanism, symptoms, forms, and how a doctor makes the diagnosis.

Parkinson's Disease: What It Is

This is a chronic neurodegenerative disease in which dopamine-producing neurons die, primarily in the substantia nigra. It belongs to the degenerative diseases of the extrapyramidal motor system: the component that controls the smoothness and precision of movements is affected.

The term "parkinsonism" is broader — it encompasses a number of diseases and conditions with similar leading symptoms: muscle rigidity, hypokinesia, tremor, postural instability. The most common form of parkinsonism is idiopathic Parkinson's disease, the cause of which remains unknown; it accounts for 70–80% of cases.

The frequency is from 60 to 140 people per 100,000 population. Among people over 60, approximately 1% have the disease; among those over 85, 2.6–4%. The first symptoms most often appear at 55–60 years of age, although early onset — before 40 — and a juvenile form — before 20 — do occur. Men are affected somewhat more often than women.

The name has persisted thanks to history: in 1817, the Englishman James Parkinson described six patients with shaking palsy, and Jean Charcot introduced his name into use.

What Happens in the Brain in Parkinson's Disease

Neurons of the substantia nigra die, and dopamine production falls. This neurotransmitter is involved in regulating body movements: when there is less of it, the basal ganglia begin to excessively inhibit the cerebral cortex, and movements lose their usual speed, amplitude, and precision.

Why cells die has not been definitively established. Most specialists believe that a combination of genetic predisposition and environmental factors comes into play. About 15% of people with Parkinson's disease have a family history, but the genes responsible for it have not been identified; among external factors, pesticides and heavy metal salts are discussed.

Main Symptoms: Motor and Non-Motor

Symptoms increase gradually and often begin on one side of the body, eventually affecting both. There are four cardinal motor signs:

• tremor of the hands, legs, jaw, and face, noticeable at rest;
• slowness of movements — hypokinesia;
• stiffness and inflexibility of the muscles of the arms, legs, and trunk;
• postural instability and poor coordination of movements.

As the disease progresses, walking, speech, and simple everyday tasks become more difficult, and problems with chewing and swallowing appear. The non-motor part of the picture is no less noticeable: depression and anxiety, insomnia or other sleep disturbances, memory decline, loss of smell. Instability increases the likelihood of falls.

Forms of the Disease and Its Course

The term "parkinsonism" covers various conditions: in addition to idiopathic Parkinson's disease, a similar picture is produced by chronic cerebrovascular insufficiency and by taking medications with extrapyramidal side effects. Early onset — before 40 — and the juvenile form are distinguished separately.

The course is slowly progressive: over time, symptoms intensify, and everyday tasks require assistance. In the early stages, manifestations are usually mild, and treatment may not be required, but observation by a specialist is necessary. Modern medicine cannot yet cure the disease, but existing methods help reduce the main symptoms and preserve quality of life for longer.

How Parkinson's Disease Is Diagnosed

There is no specific test, so diagnosis can be challenging. The diagnosis is based on medical history and neurological examination: the doctor asks about complaints and their development and, if necessary, refers to a specialist.

When to See a Neurologist

A reason for consultation is tremor, slowness, muscle stiffness, changes in gait, increased frequency of falls, as well as persistent loss of smell or sleep disturbances without a clear cause.

Parkinson's disease itself is not a reason to call an ambulance; 103 or 112 — if a life-threatening condition arises, for example suspected stroke.

This material is for reference: it explains the mechanism and signs but does not replace a doctor's consultation.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer