About parkinson's disease and movement disorders
Parkinson's disease develops when the brain cells that produce dopamine gradually stop working. It causes slowness of movement, stiffness, a tremor at rest and changes in walking and balance, and often non-movement symptoms too: loss of smell, constipation, sleep disturbance, low mood and, later, thinking changes. It affects around 12,000 people in Ireland and is more common with age, though one in ten is diagnosed under 50.
Essential tremor is a shaking of the hands, and sometimes the head or voice, that is worse when holding a posture or doing something. Dystonia causes sustained muscle contractions and abnormal postures. Tics, chorea, myoclonus and drug-induced movement disorders are also seen in the clinic.
Symptoms we assess
Reasons for referral include:
- Tremor of a hand, either at rest or when using it
- Slowness, stiffness or a change in handwriting (smaller, cramped)
- A shuffling walk, reduced arm swing or difficulty turning
- Loss of facial expression or a quieter voice
- Abnormal postures or twisting of the neck, hand or foot
- Acting out dreams, loss of smell or constipation together with any of the above
- Involuntary movements after starting a new medication
How we diagnose it
Parkinson's disease and most movement disorders are diagnosed clinically, by a neurologist watching how you move. The consultant takes a detailed history, including medication, family history and non-movement symptoms, and examines tone, speed of movement, tremor, posture, walking and balance. Because the examination is the test, the first appointment is unhurried.
Imaging is used to exclude other causes rather than to confirm Parkinson's. MRI is arranged where the picture is atypical. A DaT scan, which shows dopamine activity in the brain, is used in selected cases where Parkinson's and essential tremor cannot be separated clinically. Blood tests exclude thyroid disease and other contributors to tremor.
Treatment and follow-up
Parkinson's disease is treated with medicines that replace or mimic dopamine. Levodopa remains the most effective, and the consultant explains how and when to start it, how to adjust it as the condition changes and how to manage the fluctuations that can develop over years. Newer formulations, add-on drugs and, for selected patients, deep brain stimulation are discussed as they become relevant.
Exercise is the other treatment with proven benefit, and the consultant will direct you to physiotherapy, speech therapy and occupational therapy as needed. Non-movement symptoms, from sleep to mood to blood pressure, are actively looked for and treated.
Essential tremor responds to specific medications and, where severe, to focused ultrasound or deep brain stimulation. Dystonia is treated with botulinum toxin injections into the affected muscles and with medication. All patients are followed long term, with letters to the GP after every visit.
When to see a GP, and when to see a consultant
Tremor and slowness should be assessed by a neurologist rather than watched, because early diagnosis gives the widest treatment choice and because some causes are reversible. Ask your GP for a referral for any new tremor, stiffness or change in walking, for known Parkinson's disease without regular specialist review, or for involuntary movements of any kind.
