Parkinson’s disease is a progressive neurological disorder that affects movement. The key symptoms of Parkinson’s disease are tremors, rigidity, and slowness of movement. The tremors associated with Parkinson’s typically start in the hand, arm, or leg and can affect one side of the body or both sides. The tremors are caused by the death of dopamine-producing brain cells that affect coordination and movement. As Parkinson’s progresses, the tremors may spread to other parts of the body and can become more severe. While tremors are a classic symptom of Parkinson’s, identifying which part of the body shakes first can help doctors diagnose the disease earlier.
What causes the tremors in Parkinson’s disease?
The tremors associated with Parkinson’s disease are called “resting tremors.” This means the tremors occur when the affected limb is relaxed and fully supported against gravity, such as when the hands are resting on the lap. Resting tremors typically start in the hand, although they may also originate in the feet, jaw, lip, face, head, or leg.
The tremors are caused by the loss of nerve cells in a part of the brain called the substantia nigra. These cells produce dopamine, a neurotransmitter that coordinates and controls muscle movement. As dopamine levels decrease, communication between the brain and muscles breaks down, resulting in uncontrollable shaking or tremors. The tremors usually begin on one side of the body, commonly in one hand. As the disease progresses, tremors may spread to both sides of the body. However, the tremors tend to remain more pronounced on the initially affected side.
What are the stages of Parkinson’s disease?
Parkinson’s disease typically progresses through several stages:
Stage 1
The first stage of Parkinson’s disease is often called the “honeymoon period.” At this point, symptoms are mild and generally limited to one side of the body. The most common initial symptoms are a mild tremor or shakiness in one hand, arm, leg, jaw, or foot. Friends and family may not even notice the tremor at this stage. Other early symptoms include hand cramps, aches, fatigue, soft speech, and mask-like facial expressions. Stage 1 usually lasts 2-4 years before progressing.
Stage 2
In stage 2, symptoms begin affecting both sides of the body. Tremors and rigidity may make daily tasks more challenging. Other stage 2 symptoms include slowness of movement (bradykinesia), stooped posture, balance problems, loss of facial expression, and monotone voice. Walking may become slower and more difficult. Patients may also experience depression, anxiety, irritation, and mild memory problems. Stage 2 typically lasts 2-10 years.
Stage 3
During stage 3, Parkinson’s symptoms become more severe and disabling. Tremors and rigidity make movements difficult and significantly limit mobility. Patients may experience significant functional impairment in their ability to walk, talk, complete personal care tasks, and live independently. Additional symptoms in stage 3 include increased memory loss, confusion, nightmares, hallucinations, constipation, urinary issues, blood pressure changes, and sleep disruptions.
Stage 4
The final stage of Parkinson’s involves severe symptoms and disability. Tremors may cause falls, and patients often require a wheelchair or are bedridden. Speech and swallowing difficulties are also common at this stage. Symptoms are no longer controlled by medication, and patients usually require around-the-clock nursing care. Stage 4 typically lasts 1-5 years, leading to death most frequently from aspiration pneumonia.
What are the early symptoms of Parkinson’s disease?
Some of the earliest symptoms of Parkinson’s disease include:
– Tremor – This is often the first noticeable symptom starting in one hand, arm, leg or jaw. The tremor associated with Parkinson’s occurs when the limb is at rest.
– Bradykinesia – Slowed movement and progressive loss of spontaneous movement over time. Daily tasks require more effort and take longer to complete.
– Rigidity – Stiffness and tension in the limbs or trunk of the body. Muscles resist being moved passively by an examiner.
– Impaired posture and balance – Stooped, forward-leaning posture and balance problems that increase the risk of falls.
– Loss of automatic movements – Changes in facial expression, decreased blinking, reduced arm swinging when walking.
– Speech changes – Quiet, breathy, monotone voice or slurred/slow speech.
– Writing changes – Small, cramped handwriting that progresses to difficulty writing.
– Sleep disturbances – Excessive daytime sleepiness, insomnia, or vivid dreaming.
– Dementia – Mild cognitive impairment including memory loss, attention deficit, and slow thinking.
Which part of the body shakes first with Parkinson’s?
In most cases, Parkinson’s tremors begin in the hand on one side of the body. According to the Parkinson’s Foundation, tremors start in one of these three areas in 65-70% of people with Parkinson’s:
| Location | Percentage |
|---|---|
| Fingers or thumb on one hand | 50% |
| Hand | 15% |
| Arm | 15% |
Less commonly, the tremors may initially occur in the:
– Jaw – Seen as shaking or quivering of the chin area.
– Lip – Causes a tremor or quiver of the lips when holding them tightly together.
– Face – Tremors may cause blinking, grimacing, or spasms in the facial muscles.
– Foot – Shaking of one foot when it is relaxed and hanging freely.
– Leg – Tremor or shaking sensation originating in the thigh, calf, or entire leg.
– Head – Causing a back and forth shaking of the head.
– Neck – Seen as rhythmic shaking of the neck, usually from side to side.
– Trunk – Causing a slight shaking of the chest, abdomen, or trunk while sitting or standing.
Why do the tremors start on one side of the body?
In Parkinson’s disease, the loss of dopamine-producing cells occurs in a region of the brain called the substantia nigra pars compacta. This area is located in the midbrain on both sides of the brain stem.
The substantia nigra cells begin dying on one side of the brain first, leading to the asymmetrical symptoms often seen in early Parkinson’s. Since dopamine helps control muscle movement, the loss of these brain cells on one side disrupts coordination on the opposite side of the body.
This is why tremors typically start in the hand, arm, or leg on just one side of the body in the early stages of Parkinson’s disease. As Parkinson’s progresses and more dopamine-producing brain cells die off, the tremors often spread to both sides of the body. However, the tremors tend to remain more pronounced on the initially affected side.
How do doctors diagnose the shaking side in Parkinson’s disease?
Doctors use various neurological exams and tests to diagnose which side of the body shakes first in Parkinson’s disease:
– Observation of tremors – The doctor observes the resting tremors affecting the hands, feet, or other areas during the office visit.
– Patient histories – The doctor asks about where tremors or other symptoms first appeared.
– Motor examination – The doctor may check for rigidity, slow movements, and tremors on each side of the body.
– Dopamine transporter (DAT) scan – This imaging test shows dopamine loss in the substantia nigra on one or both sides of the brain.
– Single-photon emission computerized tomography (SPECT) scan – SPECT imaging can detect decreased blood flow in the basal ganglia on the affected side.
Once the shaking side is determined, doctors can better track the expected pattern of Parkinson’s progression and response to medications.
What is the importance of identifying the shaking side?
Identifying which side of the body shakes first in Parkinson’s provides several key insights for diagnosis and treatment:
– Confirms the Parkinson’s diagnosis – The asymmetrical presentation of tremors or rigidity points to Parkinson’s disease as the likely diagnosis.
– Helps rule out other causes – Symptoms affecting just one side of the body indicates the cause is within the brain rather than disorders that typically cause tremors on both sides.
– Predicts expected disease progression – Parkinson’s symptoms often spread from one side of the body to the other in a predictable pattern.
– Assesses treatment effectiveness – Monitoring symptoms on each side helps doctors determine if medications are improving tremors and control.
– Evaluates eligibility for surgery – Surgeries like deep brain stimulation work best for tremors affecting primarily one side of the body.
– Indicates the initially affected side – The first side involved typically remains more affected throughout the disease.
– Correlates with brain imaging – Imaging showing dopamine loss on one side correlates with the clinical symptoms on the opposite side.
Overall, identifying the shaking side guides Parkinson’s diagnosis, prognosis, and management for the greatest treatment benefit.
What are effective treatments for Parkinson’s tremors?
While there is currently no cure for Parkinson’s disease, several effective treatments help reduce tremors and improve symptoms:
– Levodopa – The standard oral medication converted to dopamine in the brain. It helps increase dopamine levels and reduce tremors.
– Dopamine agonists – These medications mimic dopamine effects by binding to dopamine receptors in the brain. Examples are pramipexole, ropinirole, rotigotine.
– Anticholinergics – Medications that block acetylcholine signaling to help control tremors in early Parkinson’s. They include trihexyphenidyl, benztropine, ethopropazine.
– Monoamine oxidase (MAO-B) inhibitors – These prevent the breakdown of dopamine. Selegiline and rasagiline are examples.
– Deep brain stimulation – This surgery implants electrodes into the brain and stimulates targeted areas to reduce tremors.
– Focused ultrasound – Highly focused ultrasound waves modulate brain areas involved in tremors and improve symptoms.
– Life adjustments – Making lifestyle changes to avoid triggers, practice relaxation techniques, improve sleep, and increase exercise.
While challenging to live with, Parkinson’s tremors can often be well-managed through an individualized treatment approach and tapping into available support resources.
Conclusion
In most people with Parkinson’s disease, tremors start in one hand, arm, leg, or foot on just one side of the body. This shaking or tremor occurs when the limb is relaxed and at rest. The asymmetrical presentation of symptoms is due to the loss of dopamine-producing cells in one side of a brain area called the substantia nigra.
Identifying the first shaking side is important for diagnosis and tracking Parkinson’s progression. Doctors determine the initially affected side through observation, patient histories, neurological exams, and brain imaging tests. Recognizing the shaking side can guide more effective treatments and management. While Parkinson’s is a progressive disease, medications, surgery, therapy, and lifestyle changes can help control tremors and improve quality of life.