The neurological signs observed in sheep during hypoglycaemia, induced by doses of insulin ranging from 1 to 10 units per kg., are described in detail. The signs varied in intensity from mild lassitude through muscular spasms to collapse and convulsive activity. The severity of these disturbances was closely correlated with the level of blood glucose and the period during which it remained at a particular level. Levels of less than 5 mg. per cent. were invariably associated with signs which progressed beyond the stage of mild lethargy. Convulsive activity was seen only after the blood glucose had been reduced to negligible levels, less than 1 mg. per cent., and had remained there for upwards of one hour. Hypoglycaemic convulsions in rats were also found to occur at virtually negligible blood-glucose levels.Attention is drawn to the considerable volume of literature which, particularly when the errors of analytical methods are taken into consideration, supports the contention that the blood glucose is negligible at the onset of convulsions in non-ruminant species, just as it is in the sheep.
