Brain imaging correlates of mild cognitive impairment and early dementia in patients with type 2 diabetes mellitus.

BACKGROUND AND AIMS: The risk of mild cognitive impairment and dementia is increased in type 2 diabetes mellitus (T2DM). We aimed to identify the neuroanatomical correlates of mild cognitive impairment (MCI) and early dementia in patients with T2DM, using advanced multimodal MRI. METHODS AND RESULTS: Twenty-five patients (≥70 years) with T2DM and MCI (n = 22) or early dementia (n = 3) were included. The reference group consisted of 23 patients with T2DM with intact cognition. All patients underwent a 3 T MRI. Brain volumes and white matter hyperintensity volumes were obtained with automated segmentation methods. White matter connectivity was assessed with diffusion tensor imaging and fiber tractography. Infarcts and microbleeds were rated visually. Compared to patients without cognitive impairment, those with impairment had a lower grey matter volume (effect size: -0.58, p=0.042), especially in the right temporal lobe and subcortical brain regions (effect sizes: -0.45 to -0.91, false discovery rate corrected p < 0.05). White matter volume (effect size: -0.47, p = 0.11) and white matter connectivity (effect size: 0.55, p = 0.054) were also reduced in patients with versus without cognitive impairment, albeit not statistically significant. White matter hyperintensity volumes and occurrence of other vascular lesions did not differ between the two patient groups. CONCLUSION: In patients with T2DM, grey matter atrophy rather than vascular brain injury appears to be the primary imaging correlate of MCI and early dementia.

Case-finding for cognitive impairment among people with Type 2 diabetes in primary care using the Test Your Memory and Self-Administered Gerocognitive Examination questionnaires: the Cog-ID study.

AIM: To evaluate two cognitive tests for case-finding for cognitive impairment in older patients with Type 2 diabetes. METHODS: Of 1243 invited patients with Type 2 diabetes, aged ≥70 years, 228 participated in a prospective cohort study. Exclusion criteria were: diagnosis of dementia; previous investigation at a memory clinic; and inability to write or read. Patients first filled out two self-administered cognitive tests (Test Your Memory and Self-Administered Gerocognitive Examination). Secondly, a general practitioner, blinded to Test Your Memory and Self-Administered Gerocognitive Examination scores, performed a structured evaluation using the Mini-Mental State Examination. Subsequently, patients suspected of cognitive impairment (on either the cognitive tests or general practitioner evaluation) and a random sample of 30% of patients not suspected of cognitive impairment were evaluated at a memory clinic. Diagnostic accuracy and area under the curve were determined for the Test Your Memory, Self-Administered Gerocognitive Examination and general practitioner evaluation compared with a memory clinic evaluation to detect cognitive impairment (mild cognitive impairment or dementia). RESULTS: A total of 44 participants were diagnosed with cognitive impairment. The Test Your Memory and Self-Administered Gerocognitive Examination questionnaires had negative predictive values of 81 and 85%, respectively. Positive predictive values were 39 and 40%, respectively. The general practitioner evaluation had a negative predictive value of 83% and positive predictive value of 64%. The area under the curve was ~0.70 for all tests. CONCLUSIONS: Both the tests evaluated in the present study can easily be used in case-finding strategies for cognitive impairment in patients with Type 2 diabetes in primary care. The Self-Administered Gerocognitive Examination had the best diagnostic accuracy and therefore we would have a slight preference for this test. Applying the Self-Administered Gerocognitive Examination would considerably reduce the number of patients in whom the general practitioner needs to evaluate cognitive functioning to tailor diabetes treatment.

[Doppler ultrasound determination of vascular resistance in arteriovenous shunts of the finger tip]. / Dopplersonographische Bestimmung des Gefässwiderstandes in arteriovenösen Shunts der Fingerbeere.

AIM: Doppler sonographic assessment of physiological bloodflow characteristic in arteriovenous shunts of the fingertip and calculation of vascular resistance. Identification and definition of a peripheral, physiological resistive index in healthy volunteers. METHOD: Doppler sonographic measurement of bloodflow values in Hoyer-Grosser organs of the fingertip in 20 healthy volunteers. Measurements were repeated at normal air temperature (21 degrees C) and after submersion in water (15 degrees C). The resistive index was calculated from peak systolic velocity and minimal diastolic velocity. RESULTS: Although bloodflow values vary in a wide range, the resistive index is constant with 0.54 (range 0.45-0.69) in healthy volunteers. Characteristic sonographic flow patterns could be achieved in all tests. CONCLUSIONS: Colour Doppler sonography allows identification of small arterio-venous shunts of the fingertip, measurement of bloodflow in these vessels and calculation of vascular resistance. At normal air temperature the physiological resistive index is 0.54.

Pharmacological properties of colloidal bismuth subcitrate (CBS, DE-NOL).

In pharmacological ulcer models in rats colloidal bismuth subcitrate (CBS) demonstrated anti-ulcer activity. This was neither a result of an acid neutralizing nor of an acid secretion inhibitory effect. Both in vitro and in vivo, an anti-peptic action was found. At low pH CBS precipitates and was shown to form a coating on the gastric wall especially on the ulcer crater. This coating most likely forms a protective barrier to the peptic activity of gastric juice. Low toxicity was seen following chronic daily administration of high doses of CBS for 3 months to rats and 6 months to dogs. Although the blood levels were more elevated in rats, the tissue bismuth levels were comparable in the two species (except for the caecum). The chief bismuth-excreting organs, the kidneys, showed relatively high concentrations, while the brain-concentrations were extremely low in concordance with the absence of nervous system toxicity.

Anti-ulcer activity of colloidal bismuth subcitrate in Shay-rats.

The anti-ulcer action of colloidal bismuth subcitrate (CBS) was tested in rats with a ligated pylorus (the Shay preparation). The liquid form used in the clinic displayed a dose-related inhibition of gastric ulceration. the recently developed solid form appeared to be just as effective. On the other hand, non-processed, non-colloidal bismuth salts and the CBS vehicle blank were completely inactive. The anti-ulcer activity of CBS was found to be unrelated to its buffering capacity.