10 - Intracranial Tumours

10.1About intracranial tumours

Intracranial tumours are tumours that develop inside the cranium, the upper portion of the skull that protects the brain.  Primary tumours are those which originate from within the cranium and metastatic tumours are those which result from cancers which spread (metastasize) from other parts of the body. Metastatic tumours are by far the more common type of intracranial tumour in adults, 10 times more common than primary tumours.

Primary tumours may be classified as either benign (non-cancerous) or malignant (cancerous).  Malignant tumours are graded on a scale of 1 to 4, with grade 4 being the most severe, based on how abnormal they are compared to normal tissue and how quickly they are likely to grow and metastasize.

Typically, the treatment options for intracranial tumours are surgery, radiation and chemotherapy, alone or in combination, regardless of whether the tumour is primary or metastatic, benign or malignant.  For primary tumours, the probability of successful treatment depends on a number of factors, including the type of tumour, size and location.

Treatment will rarely cure a metastatic tumour, and the goal of treatment is generally to reduce symptoms, increase length of survival and improve quality of life.

Impairments associated with intracranial tumours vary depending on the tumour type, location and rate of growth, and can affect cognitive, motor or sensory functions.

Examples of possible impairments include:

  • cognitive impairment
  • epilepsy
  • personality changes
  • focal weakness, and
  • sensory disturbances

The presentation of impairments may be progressive or variable.

10.2Prevalence

The overall incidence of intracranial tumours in the United States is between 5 and 14 per 100,000 people (all ages), with the peak incidence in those between 65 and 79 years of age. Canadian data are lacking.

10.3Intracranial tumours and adverse driving outcomes

No studies on the effects of intracranial tumours on driving were found.

10.4Effects on functional ability to drive

Condition Type of driving impairment and assessment approach Primary functional ability affected Assessment tools
Intracranial tumour Persistent impairment: Functional assessment Variable – cognitive, motor or sensory

Medical assessments

Functional assessment

Episodic impairment: Medical assessment – likelihood of impairment Variable – sudden impairment (epilepsy) Medical assessments

An intracranial tumour may result in a persistent cognitive, motor or sensory impairment, or an episodic impairment (epilepsy), or both.

10.5Compensation

Drivers who have experienced a persistent impairment of motor or sensory function may be able to compensate.  An occupational therapist, driver rehabilitation specialist, driver examiner or other medical professional may recommend specific compensatory vehicle modifications or restrictions based on an individual functional assessment.

Some examples of compensatory mechanisms are shown in the following table.

Motor impairment Sensory (vision) impairment
  • Steering wheel spinner knob
  • Restriction to automatic transmission or power-assisted brakes
  • Scanning horizon more frequently
  • Turning head 90◦ to maximize area scanned
  • Large left and right side mirrors

10.6Guidelines for assessment

10.6.1 Intracranial tumour

If a driver has epilepsy as a result of an intracranial tumour, also see the standards in Chapter 17.

National Standard

All drivers eligible for a licence if

  • movement and strength are sufficient to perform the functions necessary for driving
  • cognitive and visual functions necessary for driving are not impaired
  • any pain associated with the condition, and any treatment for the condition, do not impair the functional abilities necessary for driving
  • where required, a road test or other functional assessment indicates that the driver is able to compensate for any loss of functional ability necessary for driving, and
  • the conditions for maintaining a licence are met
BC Guidelines
  • If further information regarding an individual’s medical condition is required, RoadSafetyBC may request
    • a Driver’s Medical Examination Report
    • additional information from the treating physician, or
    • an assessment from a specialist.
  • If the treating physician indicates possible impairment of one or more of the functions necessary for driving, RoadSafetyBC may request functional assessment(s) as appropriate for the type(s) of impairment and class of licence held, unless there has been no significant change in the individual’s condition or functional ability since a previous functional assessment
Conditions for maintaining licence No conditions are required
Restrictions

RoadSafetyBC may restrict an individual’s licence so that they only drive with any permitted vehicle modifications and devices required to compensate for their functional impairment. This may include one or more of the following restrictions

  • 26        Specified vehicle modifications required
  • 28        Restricted to automatic transmission
  • 51        [specify type of restriction]
Reassessment RoadSafetyBC will re-assess every 5 years or in accordance with routine commercial or age-related re-assessment, unless a shorter re- assessment interval is recommended by the treating physician. No further re-assessment is required if the tumour is successfully removed
Information from health care providers
  • Whether the driver suffers from epilepsy as a result of the tumour. See the standards under Chapter 17 if epilepsy is present
  • Opinion of treating physician on whether the driver has a loss of movement or strength that may affect functional ability to drive
  • Opinion of treating physician on whether pain or treatment may adversely affect functional ability to drive
  • Opinion of treating physician on whether the driver suffers from diplopia and/or a visual field deficit that may affect functional ability to drive.  See the standards under Chapter 22 if the treating physician indicates that either of these conditions may be present.
  • Results of cognitive assessment
  • Where required, the results of a functional assessment
Rationale The potential functional impairments associated with an intracranial tumour are variable