Parkinson’s Disease and Driving
Sex and age
- Non-pathological history: Retired, no known allergies to medications. Occasional smoker. Barthel’s Index: moderately dependent.
- Pathological history: Type 2 DM and high blood pressure being treated by medication; hyperuricemia, neoplasia of the left kidney treated by nephrectomy, Parkinson’s disease being monitored by the neurology service.
- Surgical history: nephrectomy of left kidney (2010), cataract surgery on left eye (2005).
Stalevo (Levodopa 50 mg; Carbidopa 12.5 mg; Entacapone 200 mg) 1-1-1/2, Torasemide 10mg 1-1/2-0, Metformin 850 mg, fast-action insulin.
Loss of approximately 5 kg in the last month, hyporexy, asthenia, general weakness, tendency to feel drowsy, choluria, which the patient associates with starting to take Stalevo.
- Conscious and orientated, sleepy, skin and mucous membranes regularly hydrated, normal coloration.
- Cardiovascular: Rhythmic precordium, no additional pathological murmurs.
- Respiratory: Preserved respiratory noise, no audible catarrh or wheezing.
- Abdomen: Flat, soft, depressible, not painful, no masses or visceromegaly found, peristalsis (+) normal.
- Lower limbs: Complete, symmetrical, no coloration changes, no edemas. No signs of DVT.
Probable side effects to Parkinson’s disease medication.
Parkinson’s disease: Parkinson’s disease (PD) is a chronic degenerative disease of the nervous system caused by the death of the dopaminergic cells in the black substances of the midbrain and is characterized clinically by resting tremor, cogwheel rigidity, bradykinesia and postural instability.
Epidemiology: The prevalence of Parkinson’s symptoms is very high, presenting in some 15% of elderly people and up to 50% of people over 80. Parkinson’s disease is the main cause of Parkinsonian symptoms and in industrialized countries is the second most prevalent degenerative nervous system disease after Alzheimer’s disease. The World Health Organization estimates that there are 40 million Parkinson’s disease sufferers worldwide and a further 30% who have not yet been diagnosed.
Etiology and risk factors: It is known that the presentation of PD is due to an interaction of various environmental and genetic factors, many of which are still under study. It has been shown that age and a family history of PD are the main risk factors for its development, yet there are many other risk factors such as: pesticides, herbicides, heavy metals, obesity, diabetes and traumatic brain injury, amongst others. There are also protective factors, such as: caffeine, tea, alcohol, vitamin E, exercise and taking certain non-steroidal anti-inflammatory drugs and statins.
Clinical symptoms and classification: The appearance of Parkinson’s disease symptoms tends to be insidious, so it is difficult to make an exact diagnosis in the early stages; there are four cardinal signs of the disease:
- Resting tremor : Present in up to 70% of patients. This is a course tremor, disappears while sleeping and worsens in situations of stress. It affects the hands, feet, face, jaw, tongue muscles and, more rarely, the head.
- Movement disorders : These can be characterized by bradykinesia (slowing-down of movements), akinesia (difficulty initiating movement) and hypokinesia (limitations to the scope of movements). They mainly affect the face and distal muscles and it is one of the most incapacitating symptoms.
- Rigidity . This occurs in up to 90% of patients and starts in the same extremity as the tremor, if tremor is present. It occurs due to increased muscle tone, leading to greater resistance to passive movement in the affected limb (“cogwheel rigidity”).
- Postural instability. This appears in the most advanced stages of the disease as a result of impairment of the postural reflexes. It causes a backward lean (known as retropulsion) or a stooped forward posture with the head bowed and shoulders dropped. This is one of the factors that increases the number of falls in these patients.
The most widely-used scale to evaluate the stage and severity of Parkinson¡s disease is the Hoehn and Yahr scale, given its ease of use in daily clinical practice. Hoehn and Yahr stages:
- Stage 1
- Symptoms on one side only.
- Mild symptoms.
- Disturbing but not incapacitating symptoms.
- Presence of tremor symptoms in a limb.
- Friends notice certain changes to posture, facial expressions and movements.
- Stage 2
- Bilateral symptoms.
- Minimal disability.
- Movement and posture are affected.
- Stage 3
- Significant slowing-down of body movements.
- Difficulty maintaining balance whether standing or walking.
- Moderately severe general dysfunction.
- Stage 4
- Severe symptoms.
- Can still walk a short distance.
- Rigidity and bradykinesia.
- Cannot live alone.
- Tremor may be less severe than in previous stages.
- Stage 5
- Total invalidity.
- Cannot stand or walk unassisted.
- Requires nursing care
The diagnosis of PD is solely clinical and based on the following criteria:
Main diagnostic criteria
Presence of bradykinesia and at least one of the following symptoms:
- Resting tremor.
- Postural instability unrelated to visual, cerebral or vestibular deficits or proprioceptive disorders.
Diagnostic exclusion criteria
- Repeated cerebrovascular accidents.
- Repeated brain damage.
- Use of anti-psychotic or anti-dopaminergic drugs.
- Presence of untreated encephalitis and/or oculogyric crises.
- Presence of other neurological symptoms: supranuclear palsy, cerebellous signs, severe deterioration in autonomy in the early stages, Babinski sign, dementia or severe language or memory disorders in the early stages.
- Presence of a brain tumor or hydrocephalus in neuroimaging tests.
- Exposure to a known neurotoxin.
- More than one member of the family affected.
- Prolonged clinical remission.
- Negative response to high doses of levodopa if poor absorption is ruled out.
Definitive diagnostic criteria
- Strictly unilateral clinical data on the disorder three years after the start of the clinical record.
- Presence of at least three of the following clinical data:
- Unilateral start.
- Presence of resting tremor.
- Progressive disorder.
- Asymmetric disorder with a greater unilateral effect from the start.
- Excellent response to levodopa.
- Levodopa-induced chorea.
- Response to levodopa for 5 years.
- Clinical course more than 10 years.
Up until now there has been no drug capable of halting the progress of Parkinson’s disease. However, given that the motor manifestations of the disease are due to the depletion of dopamine in the nigrostriatial pathway, the fundamental treatment entails administering substances or taking actions that increase this concentration.
The current treatment for Parkinson’s disease consists of replacing dopamine by means of its precursor, L-Dopa, or substances that increase the activity of this neurotransmitter on stimulating the dopaminergic receptors (Ropinirole, Pramipexole, Bromocriptine). Other drugs act by inhibiting the enzymes that destroy dopamine, such as catechol-O-methyl transferase (COMT) (Entacapone) and type B monoamine oxidase (MAOB) (Selegiline and Rasagiline).
There are also surgical treatments, the gold standard of which for treating most Parkinson’s symptoms is subthalamic deep-brain stimulation which improves the motor functions, including walking and balance, of patients with Parkinson’s disease.
Parkinson’s disease and Road Safety. Regulations and repercussions.
- Regulations on PD and driving.
The general regulations for drivers in Spain do not specify the rules for Parkinson’s disease but cover it in the section relating to the nervous and muscular system, and states that: “There should be no loss or severe impairment of motor, sensory or coordination functions, episodes of syncope, major tremors or spasms of the head, trunk or limbs, or tremors or spasms that involuntarily affect vehicle control.”
- PD and its repercussions on driving.
Parkinson’s disease causes a progressive motor disability which significantly restricts the everyday activities of patients; statistics show that even with these limitations, two out of every 10 people with PD continue driving. For this reason we need to know about the risk factors that make these patients more likely to suffer accidents and thus try to control them.
When a patient with PD who is still driving is referred to us, we need to know that the difficulties experienced by patients with Parkinson’s disease when driving vehicles are due to the main signs and symptoms of the disease: resting tremor, rigidity and bradykinesia, which from the early stages of the disease can:
- Make it difficult to perform simple motor actions.
- Affect the automatic execution of learned complex movements (patients experience difficulty in starting a movement and reaction time becomes longer).
- Be associated with non-motor manifestations such as depression or dementia.
All of this makes it more likely for there to be a slow and imprecise psychomotor response with impaired coordination (poor pedal control, difficulty in controlling the hands) and excessive fatigue.
The factor most closely associated with the risk of accidents would appear to be the presence of motor response fluctuations.
- Parkinson’s disease medication and driving.
As well as the limitations on driving ability caused by the PD itself, there are other limitations caused by its medication.
On treating patients with Parkinson’s disease, we should remember that PD medication can have a very strong effect on driving ability. The Spanish Agency for Medicines and Medical Devices classifies Parkinson’s disease medication under Group N N – Nervous System. Subgroup N04, and states that all patients who are undergoing this treatment must be warned about the possibility of the treatment causing: drowsiness and/or sudden attacks of sleepiness; they must also be informed that they should not drive a vehicle or do any activities for which a loss of alertness might put them or other people at risk of serious injury or death until such time as these episodes of drowsiness/sleepiness have stopped.
The disease often causes people to stop driving, but there is still a considerable percentage of sufferers who continue to drive. Most of them decide to stop driving of their own accord or on the advice of family members, but in very few cases have been given medical advice in this respect.
Road Safety Advice for drivers with Parkinson’s disease
- Patients should talk openly and frankly to their doctor to jointly decide on the safest driving guidelines according to the stage their disease has reached.
- Patients should strongly heed the advice of their doctor on the side effects of their medication.
- If the patient notices any warning signs such as drowsiness, abnormal movements, difficulty in moving, etc. they should slow down and stop when it is safe to do so.
- Patients should always try to drive with someone else, limit the number of hours at the wheel and avoid using vehicles for work. They should plan trips ahead, avoid driving at night and keep to regular sleeping patterns, mealtimes and medication schedules.
- Patients should try to drive on well-known routes, avoiding peak times, complicated journeys and adverse weather conditions.
- Patients should avoid speeding, risky overtaking and making unnecessary maneuvers.
- Always keep to the correct speed limit and avoid driving without a break for periods of more than one hour.
- Avoid distractions at the wheel.
- Never drink alcohol if you intend to drive.
- Ask for advice! There could be a mechanism you could use in your car to make driving easier (power steering, a knob on the steering wheel, wider pedals, etc.). Provincial Traffic Departments and driving test centers can give you advice in this respect.