Section 9: Metabolic Diseases
Hypothyroidism and Driving Literature Review
As noted previously, cognitive impairments, sleepiness, and fatigue associated with hypothyroidism have direct relevance for driving. In terms of research literature, the effects of hypothyroidism on cognitive functioning have received the most attention. Cognitive deficits associated with hypothyroidism include impairments in general intelligence (Haggerty, Evans, and Pringe, 1986; Mennemeier, Garner, and Heillman, 1993), attention and concentration (Osterweill, Syndulko, Cohen, et al., 1992), memory (Haggerty et al., 1986; Mennemeier et al., 1993), perceptual and visual functioning (Mennemeier et al., 1993; Osterweill et al., 1992), and executive/frontal lobe functioning (Mennemeier et al., 1993). It is interesting to note that many of the cognitive deficits associated with hypothyroidism do not show consistent improvement following treatment with thyroid hormone replacement therapy. It may, therefore, be important to test for cognitive deficits in individuals with hypothyroidism once they have been stabilized on thyroid hormone replacement therapy.
Table 29 Guidelines for Metabolic Diseases
(Reproduced with permission)
Should not drive. The DLA will normally issue a conditional license if condition stable. Reviews of driving status will normally be required at intervals no greater than 5 years. |
Can usually drive if:
- Has good understanding of condition.
- Follows instructions about diet, medication, and prevention of complications.
- Remains under regular supervision.
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Should not drive. Normally, the DLA will issue conditional license on certificate of physician caring for the patient on the premise that the condition is stable and all other criteria (as per guidelines) have been met. Review of condition required at maximum period of 2 years. |
Can drive if :
- Under regular medical supervision.
- Individual understands their diabetic condition and the close interrelationship between insulin demand, and diet and exercise.
- Follows physician’s advice
- No history of impairment due to alcohol or drug abuse.
- No history of severe hypoglycemic episodes in last 6 months.
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May drive if stable and eligible under general vision criteria. |
Patients with hyperthyroidism complicated by cardiac or neurologic symptoms should not drive any type of motor vehicle until the condition has been controlled. |
May drive if stable. |
Patients with symptomatic hypothyroidism should not drive any type of motor vehicle until the condition has been brought under satisfactory control. |
DLA = Driver Licensing Authority
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