Hypoglycaemia in Clinical Diabetes

Hypoglycaemia in Clinical Diabetes

(Parte 7 de 7)

Symptom scoring systems

The controversy about the effect of human insulin on symptom awareness (Chapter 7) stimulated the development of scoring systems for hypoglycaemia to allow comparative studies between insulin species. This produced scoring systems such as the Edinburgh Hypoglycaemia Scale (Deary et al., 1993), and any such system must be validated for research application. It is important to note that the nature and intensity of individual symptoms are as important as, if not more important than, the number of symptoms generated by hypoglycaemia. The concepts involved are discussed in detail by Hepburn (1993). More information on the symptoms of hypoglycaemia is provided by McAulay et al. (2001b).

Symptoms are subjective reports of bodily sensations. With respect to hypoglycaemia some of these reports – especially neuroglycopenic symptoms – pertain to altered cognitive (mental ability) functioning. Do reports of ‘confusion’ and ‘difficulty thinking’ (Table 2.2) concur with objective mental test performance in hypoglycaemia? Before experimental hypoglycaemia became an accepted investigative tool in diabetes, expert clinical observers noted impairments of cognitive functions despite clear consciousness during hypoglycaemia (Fletcher and Campbell, 1922; Wilder, 1943). Cognitive functions include the following sorts of mental activity: orientation and attention, perception, memory (verbal and non-verbal), language, construction, reasoning, executive function and motor performance. Early studies (Russell and Rix-Trot, 1975) established that the following abilities become disrupted below blood glucose levels of about 3.0mmol/l:

• fine motor co-ordination; • mental speed;

• concentration;

• some memory functions.

(Parte 7 de 7)

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