Section 11
Nervous system

Alert

  • Any seizure is grounds for immediate cessation of all driving activities.
  • Resumption of driving will depend on neurologic assessment of the patient and the nature of the driving activity that is involved.
  • Driving after a seizure caused by use of a substance depends on complete abstinence from use of that substance.
  • Lack of adherence, including forgotten doses of medications, is grounds for immediate cessation of all driving activities.

11.1 Overview

Safe driving requires concentration, a reasonable level of intelligence and maturity, complete control over all muscle movements, and freedom from the distracting influence of severe pain. In addition, a safe driver must always be alert, fully conscious, and capable of quickly appreciating and responding to changing traffic and road conditions.

A driver with a history of any type of seizures, due to epilepsy or any other cause, is generally fit to drive a non- commercial vehicle if there have been no seizures during the previous 6 months. For certain types of seizures that do not affect the level of consciousness and with symptoms that do not affect driving, the seizure-free period may be waived if the seizure pattern has remained constant for at least 12 months.

This section lists and discusses the most common neurologic conditions that can adversely affect driving ability.

11.2 Febrile or toxic seizures, benign childhood absence epilepsy, and other age-related epilepsy syndromes

Where seizures are directly related to a toxic illness, either in childhood or in adult life, and the patient has fully recovered from the illness, the seizures are of no concern in evaluating a patient’s later medical fitness to drive. Some benign childhood epilepsy syndromes remit. These would be of less concern than a current epileptic disorder. A neurologic evaluation should be obtained in all such cases.

11.3 Syncope

A single occurrence of syncope that is fully explained and, given the etiology, is unlikely to recur may require no more than close observation. However, patients with a history of several fainting spells or repeated unexplained falls should not drive until the cause has been determined and successful corrective measures taken. See Section 14.7, Syncope.

11.4 Seizures

As for all conditions, in all instances where a temporal recommendation is made, the time period should be considered a general guideline. Individual circumstances may warrant prolonging or reducing the time period suggested.

The recommendations for seizures are presented in both tabular (Table 3) and text format.

11.4.1 Single, unprovoked seizure before a diagnosis

Non-commercial drivers: These patients should not drive for at least 3 months and not before a complete neurologic evaluation — including electroencephalography (EEG) with recording while awake and asleep and appropriate neurologic imaging, preferably magnetic resonance imaging (MRI) — has been carried out to determine the cause.

Commercial drivers: Commercial drivers should be told to stop driving all classes of vehicles at once. For these drivers, there is a need for even greater certainty that another seizure will not occur while they are driving. At a minimum, commercial drivers should follow the guideline for non-commercial drivers and not drive non-commercial vehicles for at least 3 months after a single unprovoked seizure. If a complete neurologic evaluation, including EEG while awake and asleep and appropriate neurologic imaging (preferably MRI), does not suggest a diagnosis of epilepsy or some other condition that precludes driving, it is safe to recommend a return to commercial driving after the patient has been seizure-free for 12 months.

11.4.2 After a diagnosis of epilepsy

Patients may drive any class of vehicle if they have been seizure-free for 5 years, with or without antiseizure medication. However, patients with juvenile myoclonic epilepsy (Janz syndrome) may not drive any class of vehicle unless they are taking appropriate antiseizure medication.

Non-commercial drivers: Patients with epilepsy who are taking antiseizure medication should not be recommended for Class 5 or 6 licensing until the following conditions are met:

  • Seizure-free period: The patient should be seizure-free on medication for not less than 6 months. With certain types of epilepsy, this period may be reduced to not less than 3 months on the recommendation of a neurologist, provided the neurologist has stated the reasons for this recommendation. The seizure-free period is necessary to establish a drug level that prevents further seizures without adverse effects that could affect the patient’s ability to drive safely. The antiseizure medication should have no evident effect on alertness or muscular coordination.
  • Patient adherence with medication and instructions: The attending physician should feel confident that the patient is conscientious and reliable and will continue to take the prescribed antiseizure medication as directed, carefully follow the physician’s instructions, and promptly report any further seizures. Medication adherence and dose appropriateness should be supported by measurement of drug levels whenever reasonably possible.

 

TABLE 3: Recommendations for drivers who have experienced seizure
Type of seizureNon-commercial driversCommercial drivers
Single, unprovoked seizure before a diagnosis (including post-traumatic seizures not related to epilepsy)

• No driving for at least 3 months
and
• Neurologic assessment, preferably including

EEG (awake and asleep) and appropriate imaging

• No driving non-commercial vehicles for at least 3 months

and

  • Neurologic assessment, including EEG (awake

    and asleep) and appropriate imaging

  • If no epilepsy diagnosis, resume professional

    driving if seizure-free for 12 months

After a diagnosis of epilepsy

Resume driving if:

  • 6 months seizure-free* on medication
  • Physician has insight into patient adherence

  • Physician cautions against driving while

    fatigued and against alcohol use

• Resume driving if 5 years seizure-free (recommendations for individual patients may differ on an exceptional basis)
Juvenile myoclonic epilepsy (Janz syndrome)• No driving of any class of vehicle unless taking appropriate antiseizure medication
After surgery to prevent epileptic seizures• Resume driving if 12 months seizure-free after surgery, with therapeutic drug levels (recommendations for individual patients may differ on an exceptional basis)• Resume driving if 5 years seizure-free (recommendations for individual patients may differ on an exceptional basis)
Seizures only in sleep or immediately on wakening• Resume driving after 12 months from initial seizure if drug levels are therapeutic• No driving commercial vehicles for at least 5 years
Medication withdrawal or change:
Initial withdrawal or change• No driving for 3 months from the time medication is discontinued or changed• No driving for 6 months from the time medication is discontinued or changed
If seizures recur after withdrawal or change• Resume driving if seizure-free for 3 months• Resume driving if seizure-free for 6 months (recommendations for individual patients may differ on an exceptional basis)
Long-term withdrawal and discontinuation of medication• Resume driving any vehicle if seizure-free off medication for 5 years with no epileptiform activity within previous 6 months on EEG (awake and asleep)
Auras (simple partial seizures)

Resume driving if:

  • Seizures are unchanged for at least 12 months
  • No generalized seizures
  • Neurologist approves

  • No impairment in level of consciousness or

    cognition

  • No head or eye deviation with seizures

Resume driving if:

  • Seizures remain benign for at least 3 years
  • No generalized seizures
  • Neurologist approves

  • No impairment in level of consciousness or

    cognition

  • No head or eye deviation with seizures
Seizures induced by alcohol withdrawal

Resume driving if:

  • Has remained alcohol-free and seizure-free for 6 months
  • Has completed a recognized rehabilitation program for substance dependence
  • Is adherent with treatment
*Or 12 months seizure-free if seizures associated with altered awareness have occurred in previous 2 years (see text). Note: EEG = electroencephalography.

 

• Cautions: Physicians should advise patients with epilepsy that they should not drive for long hours without rest, nor should they drive when fatigued.

Patients who require antiseizure medication and who are known to drink alcohol to excess should not drive until they have been alcohol-free and seizure-free for at least 6 months. These patients often neglect to take their medication while drinking. As well, alcohol withdrawal is known to precipitate seizures, and the use of even moderate amounts of alcohol may lead to greater impairment in the presence of antiseizure medication. Patients taking these drugs should be advised not to consume more than one unit of alcohol per 24 hours.

A patient who stops taking antiseizure medication against medical advice should not be recommended for driving. This prohibition on driving may change if the physician feels confident that the formerly non-adherent patient, who is again taking antiseizure medication as prescribed, will conscientiously do so in the future and if adherence is corroborated by therapeutic drug levels, when available.

Commercial drivers: It can be unsafe for commercial drivers who must take antiseizure medication to operate passenger-carrying or commercial transport vehicles (Classes 1–4). For these drivers, there is a need for even greater certainty that another seizure will not occur while they are driving. Commercial drivers are often unable to avoid driving for long periods of time, and they frequently must drive under extremely adverse conditions or in highly stressful and fatiguing situations that could precipitate another seizure. Unfortunately, seizures do sometimes recur even after many years of successful treatment.

11.4.3 After surgery to prevent epileptic seizures

Non-commercial drivers: These patients should be seizure-free for 12 months after the surgery and should be taking antiseizure medication before being recommended for driving any type of motor vehicle. This period may be reduced to 6 months on the recommendation of a neurologist.

Commercial drivers: Before resuming driving, commercial drivers should be seizure-free for 5 years, with or without medication. However, in certain types of epilepsy, this period may be reduced to 3 years on the recommendation of a neurologist.

11.4.4 Seizures only while asleep or on wakening

Non-commercial drivers: Patients with epilepsy involving seizures that only occur while they are asleep or immediately after wakening can be recommended for a non-commercial vehicle licence (Class 5 or 6) if the seizure pattern is consistent for at least 12 months after the initial seizure or if they are seizure-free for at least 6 months.

Commercial drivers: Commercial drivers with this type of seizure and with therapeutic drug levels should not drive passenger-carrying vehicles or commercial trucks (Classes 1–4) for at least 5 years. Recommendations for individual patients may differ on an exceptional basis. There should be no prolonged post-ictal impairment in wakefulness.

11.4.5 Withdrawal of antiseizure medication or medication change

The following recommendations do not apply to voluntary cessation of antiseizure medication by the patient or instances of missed doses of prescribed medication.

Initial withdrawal or change: Some patients with fully controlled seizures whose antiseizure medication is withdrawn or changed have a recurrence of their seizures. Because the relapse rate with drug withdrawal is at least 30%–40%, patients must not drive for 3 months from the time their medication is discontinued or changed. Such patients should always be cautioned that they could have further seizures and should be counselled as to the risk factors for seizure recurrence.

The same concerns and conditions apply to commercial drivers as to non-commercial drivers. However, the period of observation before resuming driving is 6 months, and a normal EEG, preferably both awake and asleep, should be obtained during this time. If the evaluation is being done in the context of medication withdrawal, the EEG should be done when serum drug levels are non-measurable.

If seizures recur: If seizures recur after a physician has ordered discontinuation of or a change in antiseizure medication, patients can resume driving, provided they take the previously effective medication according to the physician’s instructions. Non-commercial drivers must be seizure-free for 3 months and commercial drivers for 6 months before resuming driving.

Long-term withdrawal or discontinuation: Patients with epilepsy whose antiseizure medication has been discontinued may drive any class of vehicle once they have been seizure-free off medication for 5 years, with no epileptiform activity being recorded during EEG while awake and asleep, obtained in the 6 months before resumption of driving.

11.4.6 Auras (simple partial seizures)

Non-commercial drivers: Patients with auras involving somatosensory symptoms, special sensory symptoms, or non-disabling focal motor seizures in a single limb without head or eye deviation may be eligible for a Class 5 or 6 licence, provided there is no impairment in their level of consciousness or cognition, their seizures are unchanged for more than 1 year or they are seizure-free for at least 6 months, and they have the approval of a neurologist to resume driving.

Commercial drivers: Patients with auras involving somatosensory symptoms, special sensory symptoms, or non-disabling focal motor seizures in a single limb without head or eye deviation may be eligible to drive commercial vehicles, including passenger-carrying commercial vehicles (Classes 1–4), provided there is no impairment in their level of consciousness, the seizure pattern has remained benign for at least 3 years and has never been generalized, and they have the approval of a neurologist to resume driving.

11.4.7 Seizures induced by alcohol withdrawal

As a result of chronic alcohol abuse or after a bout of heavy drinking, alcohol withdrawal can cause seizures, whether or not the person has epilepsy. Patients who have had alcohol-withdrawal seizures should not drive any type of motor vehicle. For these patients, investigation is required to exclude an underlying epileptic disorder. Before they can resume driving, these patients must complete a recognized rehabilitation program for substance dependence and must remain both alcohol-free and seizure-free for 6 months. A patient who does not have epilepsy who experiences a seizure induced by alcohol withdrawal does not usually require antiseizure medication.

11.5 Head injury and seizures

Drivers who have had a recent head injury should always be examined with particular care to determine whether there is any evidence of confusion or other symptoms that would make them temporarily unfit to drive. Although a minor head injury usually does not impair driving for more than a few hours, a more serious injury that results in even minimal residual brain damage or concussion should be fully evaluated before driving is resumed.

See also Section 16, Traumatic brain injury.

11.5.1 Post-traumatic seizure

Under certain conditions, a patient with a head injury may resume driving after a single post-traumatic seizure.

Non-commercial drivers: A patient with a single post-traumatic seizure should not drive for at least 3 months and not until a complete neurologic evaluation, including EEG with sleep recording and appropriate brain imaging, has been carried out.

Commercial drivers: A patient with a single post-traumatic seizure should not drive for at least 12 months and not until a complete neurologic evaluation, including EEG with sleep recording and appropriate brain imaging, has been carried out.

11.5.2 Post-traumatic epilepsy

The guidelines for non-commercial and commercial drivers after a diagnosis of epilepsy (Section 11.4.2, After a diagnosis of epilepsy) should be applied to those with post-traumatic epilepsy.

11.6 Disorders affecting coordination, muscle strength, and control

Loss of muscle strength or coordination occurs in a wide variety of disorders, each of which poses a special problem. These conditions include weakness, altered muscle tone, involuntary movements, or reduced coordination due to poliomyelitis, Parkinson disease, multiple sclerosis, cerebral palsy, the muscular dystrophies, myasthenia gravis, tumours of the brain or spinal cord, spinal stenosis, spina bifida, organic brain damage following a head injury or stroke, Tourette syndrome, Huntington chorea, and ataxias.

In the early stages of some of these conditions, driving restrictions may be unnecessary. However, in serious cases, it will be immediately obvious that the applicant is unable to drive safely. Drivers with Class 5 licences who have mild loss of muscle strength or control may have special controls added to their cars. The motor vehicle licensing authorities are aware of the types of controls available and where they can be obtained. After the controls have been installed, the driver must undergo a road test and satisfy an examiner that they can drive safely.

If the disorder is not progressive, a single medical examination and road test will usually suffice. However, if the condition is progressive or there are multiple medical conditions, the patient must be followed closely, and driving must be discontinued when the disability reaches the point at which driving becomes unsafe. In such conditions, the physician should recommend a functional evaluation if the patient wishes to resume driving.

If the condition is characterized by or accompanied by cognitive impairment or impairment of memory, judgment, or behaviour, or it is liable to lead to a loss of consciousness, the patient should be advised to stop driving. Any sign of cognitive impairment should trigger further evaluation of fitness to drive (see Section 8, Dementia).

In most instances, these disorders preclude holding a Class 6 licence. Patients with peripheral neuropathy causing sensory or motor symptoms should be evaluated further by a specialist.

11.7 Severe pain

Severe pain from such causes as migraine headache, trigeminal neuralgia, or lesions of the cervical or lumbar spine can decrease concentration or limit freedom of movement to a degree that makes driving extremely hazardous. This is a particular concern for commercial drivers, whose responsibilities or working conditions may prevent them from stopping work even if the pain becomes disabling.

In addition, prescription and over-the-counter painkillers may interfere with a person’s ability to drive safely. However, some patients may be rendered capable of driving despite their pain by the use of these medications. Patients who experience frequent, chronic, and incapacitating pain should be advised to avoid driving while incapacitated.

The underlying condition causing the pain may affect the person’s fitness to drive, and a functional driving evaluation may be indicated; see Section 2, Functional assessment — emerging emphasis.

11.8 Intracranial tumours

A patient who wishes to resume non-commercial or commercial driving after removal of an intracranial tumour must be evaluated regularly for recovery of neurologic function and absence of seizure activity.

11.8.1 Benign tumours

If a patient’s cognitive function, judgment, coordination, visual fields, sense of balance, motor power, and reflexes are all found to be normal after removal of a benign intracranial tumour, there is usually no reason to recommend any permanent driving restrictions.

If a seizure has occurred either before or after removal of the tumour, the patient should be seizure-free for at least 12 months, with or without medication, before resuming driving.

11.8.2 Malignant tumours

No general recommendation can be made about driving after removal of a malignant or metastatic brain tumour. The opinions of the consulting neurologist and the surgeon who removed the tumour should always be sought and each case evaluated individually. Seizures related to a brain tumour are discussed above. If there is a possibility that the tumour could recur, the physician should always fully explain to the patient the nature of the condition before sending a medical report to the motor vehicle licensing authority.

11.9 Parkinson disease and parkinsonism

During the early stages, Parkinson disease affects only fine coordination and therefore should not affect fitness to drive. With progression, impairment of the speed of gross movements and of reaction time may begin to make driving unsafe. The situation can be worsened by any associated cognitive impairment, adverse effects of medications (e.g., somnolence, involuntary movements, hallucinations), and an increasingly unpredictable response to medication leading to “wearing off” and other motor function fluctuations. The main concern is a delay in reaction time in response to complex traffic situations, which increases the risk of collision. Periodic assessment of cognitive processing speed will help in determining changes in reaction time. The Montreal Cognitive Assessment (MoCA; www.mocatest.org) may be useful in this regard, followed by an on-road test.

Resources

Koppel S, Di Stefano M, Dimech-Betancourt B, Aburumman M, Osborne R, Peiris S, et al. Influence of epilepsy and/or seizure disorders on MVC risk.
In: Charlton JL, De Stefano M, Dow J, Rapoport MJ, O'Neill D, Odell M, et al., project leads. Influence of chronic illness on crash involvement of motor vehicle drivers. 3rd ed. Report 353. Victoria, Australia: Monash University Accident Research Centre; 2021 Mar. p. 29-42. Available: https://www.monash.edu/__data/assets/pdf_file/0008/2955617/Chronic-illness-and-MVC-risk_Report-MUARC-report-no-353_JUNE2022.pdf (accessed 2022 July 4).

Koppel S, Di Stefano M, Dimech-Betancourt B, Aburumman M, Osborne R, Peiris S, et al. What is the motor vehicle crash risk for drivers with epilepsy? J Transport Health. 2021;23:101286.