Parkinson's
Tremors are involuntary, rhythmic shaking movements that can affect various parts of the body. Two of the most frequent causes of tremor are Essential Tremor (ET) and Parkinson’s, but the conditions differ significantly in their causes, symptoms, and progression.
What Are Tremors?
Tremors occur when muscles contract and relax repeatedly and uncontrollably. They can happen on their own or as part of a broader neurological condition. While tremors in Parkinson’s are linked to the loss of dopamine-producing brain cells, Essential Tremor is a separate movement disorder with its own characteristics and causes.
Essential Tremor
Essential Tremor refers to involuntary shaking in certain parts of the body, most often the hands and arms. It usually occurs without other neurological symptoms or an identifiable underlying cause, and becomes more common with age. For some people it remains mild, while for others it can become severe enough to interfere with everyday activities such as eating, writing, dressing, or using tools.
The condition often runs in families, with around half of all individuals having a genetic link. Although the exact reason for this is not fully understood, it is thought to involve changes in the parts of the brain responsible for coordinating movement.
Essential Tremor is usually most noticeable during movement and often improves at rest. It typically affects both sides of the body and may also involve the head or voice. Unlike Parkinson’s, Essential Tremor does not cause slowness, stiffness, or other neurological symptoms, which helps distinguish the two conditions.
There is no single test that confirms Essential Tremor. Diagnosis is based on recognising the pattern of symptoms, reviewing medical history, and ruling out other possible causes.
Parkinson’s
Parkinson’s is a progressive neurological condition that affects the brain and gradually worsens over time. It occurs when nerve cells that produce dopamine stop working. Dopamine helps control movement, so when levels drop, everyday tasks, such as walking, writing, or buttoning up a shirt, can become slower and more difficult.
Around 166,000 people in the UK live with Parkinson’s, and someone is diagnosed every 20 minutes. Globally, cases are expected to double to 25 million by 2050. There are more than 40 possible symptoms, and they vary from person to person. The risk increases with age, and most people diagnosed are over 50, though younger people can also develop it.
Symptoms of Parkinson’s
Symptoms develop gradually and vary for each person. Common symptoms include slowness of movement (bradykinesia), tremor, stiffness, fatigue, and smaller handwriting. Early signs can appear before movement problems and may include a reduced sense of smell, depression, anxiety, sleep difficulties, constipation, and persistent tiredness. Parkinson’s is challenging to diagnose because there is no single definitive test, and several other conditions can present with similar features.
Parkinsonism
Parkinsonism refers to a group of conditions that share symptoms such as slowness of movement, stiffness, and tremor. Parkinson’s disease is the most common, but there are related conditions with overlapping features.
Idiopathic Parkinson’s
The most common form, with an unknown cause. Symptoms vary from person to person but often include slowness of movement, tremor, stiffness, fatigue, and smaller handwriting, with early non-motor signs such as reduced sense of smell, mood changes, sleep problems, constipation, and tiredness.
Vascular Parkinsonism
Caused by reduced blood flow to the brain, often after a mild stroke. It mainly affects mobility, leading to unsteady walking, short shuffling steps, and balance problems. Other features can include bladder issues, communication difficulties, and memory problems.
Drug-Induced Parkinsonism
Triggered by certain medications, particularly neuroleptic drugs that block dopamine. Symptoms such as slowness of movement, tremor, stiffness, and walking difficulties usually appear quickly and tend to remain stable. Many people improve after the medication is stopped.
Other Related Conditions
Multiple System Atrophy (MSA) damages nerve cells and can resemble Parkinson’s, with additional problems such as bladder difficulties, dizziness, and issues with coordination, balance, and speech.
Progressive Supranuclear Palsy (PSP) causes stiffness, balance and mobility problems, and difficulties with speech, swallowing, and vision. Corticobasal Degeneration (CBD) affects movement, speech, memory, and swallowing.
Normal Pressure Hydrocephalus (NPH) involves a build-up of fluid in the brain and is associated with walking difficulties, bladder problems, and changes in thinking and memory. In some cases, a shunt is used to drain excess fluid.
Dementia with Lewy Bodies shares features with Parkinson’s, including rigidity, slower thinking, mood changes, and cognitive decline.
Wilson’s disease is a rare inherited condition that leads to excess copper in body tissues and can cause tremor, coordination and balance problems, speech difficulties, and dystonia.
