Effect of diabetes on some primitive reflexes.

Primitive reflexes (PRs) are present in newborns; they disappear as the brain matures and increase in frequency in healthy elderly individuals. Primitive reflexes are more frequent in some neurological disorders than in age-matched controls. The aim of this study was to investigate the effect of diabetes on some PRs. We examined three PRs (glabellar tap, snout and palmomental reflexes) in 376 subjects: 111 normal age-matched controls, 60 patients with cerebrovascular disease (CVD) and 205 patients with type 2 diabetes mellitus. The latter patients were divided into three groups: (1) diabetics without neurological complications (D); (2) diabetics with cerebrovascular disease (D-CVD); and (3) diabetics with polyneuropathy (D-PN). The frequency of PRs was increased in CVD, unchanged in D-CVD (except palmomental) and greatly reduced in D and D-PN. It is possible that the vascular lesions in perforating arteries of the pons in diabetic subjects, previously studied in some pathological reports, can account for the reduced occurrence of primitive reflex responses.