Parkinson’s Disease

Parkinson’s disease is a progressive neurological condition affecting movement. The issue lies deep within the brain, in areas like the basal ganglia, which sit a few centimetres beneath the outer surface and help regulate smooth, coordinated motion. Here, certain nerve cells that produce dopamine gradually stop functioning. Not abruptly, but over a period of time. As dopamine levels fall, movements lose their fluidity. They become slower, stiffer, and sometimes hesitant.

Symptoms of Parkinson’s Disease

From what we see in practice, symptoms can vary between individuals, but certain patterns tend to repeat.

Motor (movement-related) symptoms:

• Resting tremor – typically starts in one hand, often involving the thumb and index finger (“pill-rolling” movement)
• Bradykinesia (slowness of movement) – tasks like buttoning a shirt or writing may take noticeably longer
• Muscle rigidity – stiffness felt around joints such as the wrist, elbow, or knee; sometimes a “cogwheel” feel during examination
• Postural instability – balance issues, especially while turning or getting up from a chair
• Reduced automatic movements – decreased arm swing, reduced facial expression (mask-like face)
• Speech and writing changes – softer voice, smaller handwriting (micrographia)

Non-motor symptoms:

• Loss of smell (anosmia)
• Sleep disturbances – frequent awakenings, vivid dreams
• Mood changes – anxiety, low mood, apathy
• Cognitive slowing – difficulty with planning or multitasking
• Body aches or unexplained discomfort – sometimes along the neck or lower back

Tremor vs Other Movement Disorders

Not all tremors indicate Parkinson’s disease, and this distinction matters. Parkinsonian tremor usually appears when the limb is at rest, like when the hand is placed on the lap. It often reduces when the person starts using the hand. It tends to begin on one side and may remain more prominent there. In contrast, essential tremor appears during activity, like holding a glass or writing, and is often more symmetrical. It’s a subtle difference, but clinically quite significant.

Causes and Progression

The exact cause of Parkinson’s disease is not always identifiable, but several factors are known to contribute.

Possible causes and risk factors include:

• Loss of dopamine-producing neurons in the midbrain (substantia nigra region)
• Genetic factors – around 15–20% of patients may have a hereditary component
• Environmental exposure – long-term contact with pesticides, insecticides, or heavy metals
• Presence of Lewy bodies – abnormal protein deposits within brain cells
• Other contributing factors – repeated head injury, certain medications, or underlying neurological conditions

Progression is usually gradual. Symptoms often begin on one side, say, the right hand, and even when the other side gets involved, the initial side remains more affected. Over the years, additional symptoms may appear, including balance issues or cognitive changes.