2010 BC Guide in Determining Fitness to Drive

Neurogenic symptoms of hypoglycemiaThe body’s immediate response to low blood sugar is to secrete hormones that counteractinsulin, including adrenaline. The presence of adrenaline causes neurogenic (or autonomic)symptoms such as tremulousness, palpitations, anxiety, sweating, hunger, and paresthesias(tingling and numbness). People with diabetes learn to recognize these symptoms as evidence ofhypoglycemia and respond by consuming sugary liquids or starchy foods to increase their bloodglucose level.Neuroglycopenic symptoms of hypoglycemiaNeuroglycopenic symptoms are the direct result of impaired brain function due to low glucoselevels. These symptoms include confusion, weakness or fatigue, severe cognitive failure, seizureand coma. As the blood glucose level falls, higher cortical function (insight, judgment,calculation, speech and memory) is the first to be affected. Next, a person will experiencestupor, characterized by confusion, slurred speech, slow reaction times, poor judgment and lackof coordination. If the level continues to fall, there will be loss of consciousness, seizures andpotentially brain damage or death.Hypoglycemia unawarenessAnother complicating factor is hypoglycemia unawareness, which is the inability to recognizethe autonomic symptoms of hypoglycemia or a failure of such warning signs to occur prior toimpaired brain function. If the initial autonomic symptoms caused by the release of adrenalineare missed, a person experiencing hypoglycemia can only rely on the neuroglycopenic symptomsas an indicator of low blood glucose. Because these symptoms appear in the context of cognitiveimpairment, they are not easily recognized by the hypoglycemic individual and may delay orprevent self-treatment.Severe hypoglycemiaSevere hypoglycemia is commonly defined as hypoglycemia that requires outside intervention toabort, or that produces an alteration in level of consciousness or loss of consciousness. Thealtered or reduced level of consciousness prevents a person experiencing severe hypoglycemiafrom taking appropriate action.11.2 Prevalence and incidence of diabetes and hypoglycemiaDiabetesBased on research conducted by the National Diabetes Surveillance System, it is estimated thatapproximately 5% of Canadians aged 20 years and older have been diagnosed with diabetes.Diabetes is somewhat more prevalent in males, and the overall prevalence of diabetes increaseswith age as shown in Figure 1 below. It is estimated that 5 to 10% of diagnosed diabetes is type1, and 90 to 95% is type 2.86