Myasthenia gravis, loss of strength of central origin, rigid-akinetic syndromes, and their impact in driving
Myasthenia gravis
It can affect only the eye muscles or be generalized.
The most common symptoms are palpebral ptosis and intermittent diplopia, although any muscle group can be affected.
The treatment with anticholinesterasic drugs with cholinergic properties as neostigmine causes an increase of the tone and reestablishes the normal muscle operation and reduces intraocular pressure for several hours.
Muscarinic adverse events of these drugs are nausea, vomiting, diarrhea, epigastralgia, tearing, myosis, bradycardia, etc. Cholinergic digestive effects can be corrected by atropinics.
Advice on serious myasthenia
- Driving is permitted only if the symptoms of myasthenia are controlled with medical therapy.
- The specialist will report to the patient in this regard, warning him of the side effects of the medication, so that he maximizes the precaution when driving.
- Some drugs such as quinine, hydantoin, streptomycin, diazepam, and phenothiazines can worsen myasthenia or favor a spontaneous episode.
- We should avoid these drugs and, in case they are necessary, warn out patient of the possible interference with driving.
- Drivers with myasthenia gravis should be recommended to drive at daytime, when they are not tired yet.
- If they suffer diplopia or eyelid fall while driving, they should park the car and ask for assistance. Forcing driving in this situation can cause an accident.
Loss of strength of central origin
The most common cause is the vascular disease by infraction or hemorrhage.
- Hemispheric disorders: they cause paresis, and if the injuries are extensive and associated with focal neurological deficits such as dysphasia, contralateral homonymous hemianopsia, and oculocephalic deviation to the side of the injury.
- Injuries in the encephalic trunk: there occur as hemiparesis, tetraparesis, and less frequently monoparesis of contralateral localization. Some cranial pairs are affected and they are associated with a reduction of the level of consciousness.
- Spinal cord injuries: they cause ipsilateral hemiparesis, or else, tetraparesis in cervical injuries or paraparesis in dorsal injuries. They can be associated with spasticity of the extremities and sensory symptoms as paresthesia, that can start in one or both feet and rise. The motor involvement due to interruption of the corticospinal bundles causes tetraplegia or paraplegia, with increased muscle tone.
Advice on loss of strength of central origin
- The loss of strength of central origin is disabling for driving until the clinical condition subsides completely without sequels.
- Drivers with persistent or definitive motor disorders should be assessed in their disability in order to try to adapt their car to their situation and that they can drive with the restrictions set out by the law.
Rigid-akinetic syndromes
They are characterized by poverty of movements, slowness, and weariness in carrying them out, and rigidity with significant muscular tension, that produces a strong resistance to passive movement.
Advice on rigid-akinetic syndromes
- In any of the above situations, the patient cannot drive, and the physician should warn the patient and his relatives about it.
Parkinson’s disease
It is characterized by akinesia, bradykinesia, stiffness, tremor of rest that increases with anxiety and disappears with sleep, and postural instability.
The slow movements affect those requiring more precision, to progressively interfering with all daily life activities, including driving.
The patients can eventually remain still, without barely blinking, and without being able to read nor write.
The rigidity affects more the neck and the extremities, and the straight position of gait cannot be maintained, with equilibrium disorders and frequent falls. Depressive symptoms are almost always present and dementia is frequently established.
They have difficulty to handle car pedals and react slowly to unexpected events in the traffic.
The treatment with L-Dopa is symptomatic and as side effects such as digestive intolerance, orthostatic hypotension, cardiac arrhythmia that can be serious, as well as psychiatric disorders.
The adverse events of central origin of the treatment with L-Dopa appear around two years and are characterized by motor fluctuations, dyskinesia and strong somnolence.
Accordingly, these patients present symptoms caused by the disease itself, and also symptoms more complicated by the treatment.
Parkinsonisms
Secondary to infections, toxic substances, cerebrovascular diseases, metabolic calcium disorders, brain injuries, amyotrophic diseases of the central nervous system, among others.
Favored by drugs such as neuroleptic, reserpine, alpha-methyldopa, lithium, amiodarone, phenelzine, meperidine, amphotericin B, cephaloridine, diltiazem, ethanol, procaine, tricyclic antidepressants, and valproate.
It is important that physicians warn their patients that are in these conditions, of their possibility to develop parkinsonism, and the interference of the symptoms while driving.
Advice on Parkinson’s disease
- The diseases characterized by slow motor impairment of the movements and poor response, cognitive loss with difficulty in the reactivity, are disabling for driving.
- The patient should visit his physician for any doubt, and if the presence of symptoms of secondary parkinsonism is confirmed, although it is beginning, he should be advised against driving until the clinical condition subsides.
- In evolutive diseases with movement and position disorders, it is advised against driving on a permanent basis.
- When the patient is diagnosed of Parkinson’s disease, the symptoms characteristic of the disease will be disabling for driving.
- Furthermore, the drugs used can cause adverse reactions that would hinder driving further, and should be noticed.