Monthly Archives: February 2009

Here is an important study on how your blood sugar matters to the health of your brain. If you have diabetes, take it seriously and make sure your blood sugar is tightly controlled.

Impact of fasting glycemia and regional cerebral perfusion in diabetic subjects: a study with technetium-99m-ethyl cysteinate dimer single photon emission computed tomography. Cosentino F, Battista R, Scuteri A, De Sensi F, De Siati L, Di Russo C, Camici GG, Volpe M. Stroke. 2009 Jan;40(1):306-8.

BACKGROUND AND PURPOSE: Diabetes mellitus increases the risk of ischemic stroke. The aim of this study was to investigate the correlation between fasting plasma glucose (FPG) and changes in regional cerebral perfusion (CP) in subjects with DM.

METHODS: CP was assessed in 24 subjects (mean age 44+/-2.5 years) with type 1 diabetes mellitus by single photon emission computed tomography.

RESULTS: Analysis of CP during elevated FPG (224+/-24 mg/dL) showed 3 or more deficits in 42% of the subjects. A positive relationship between the number of CP deficits and FPG was observed (P<0.01), but not with age, sex, body mass index, or duration of diabetes mellitus. Regional deficits were reduced (P<0.001) with improvement in FPG (119+/-5 mg/dL). This reduction remained significant after adjustment for age, sex, and body mass index. Plasma levels of P-selectin, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1, established markers of endothelial dysfunction, were significantly decreased with lower FPG. Furthermore, thiobarbituric acid reactive substance plasma levels, an index of oxidative stress, were also reduced (P<0.01).

CONCLUSIONS: The present study demonstrates that changes in FPG are associated with functional changes in regional CP. Hyperglycemia-induced endothelial dysfunction may be implicated in the impaired regional CP of diabetic subjects.

From Australia comes a fascinating study correlating smell deficits with ADHD. As we have seen at the Amen Clinics, ADHD is often associated with low activity in the inferior orbital prefrontal cortex, which is very close to the olfactory or smell area of the brain. Smell identification deficits was found to be significant in Alzheimer’s disease. In our book Preventing Alzheimer’s we argues that ADHD may be a risk factor for Alzheimer’s disease. Hmmm.

Enjoy the abstract.

OBJECTIVE: This study compared unilateral olfactory identification abilities in children with and without attention-deficit/hyperactivity disorder (ADHD) and evaluated the utility of the University of Pennsylvania Smell Identification Test (UPSIT) as a potential screening tool for the diagnosis of ADHD.

METHOD: Subjects comprised 44 children with DSM-IV ADHD (aged 7-16 years) from 2 Melbourne, Australia, hospital outpatient clinics and 44 healthy children matched for age and sex. The children were assessed from March 2004 to October 2004 for olfactory identification ability using the UPSIT, and behavioral data were gathered using the Rowe Behavioral Rating Inventory. Background and demographic data were also obtained through hospital records and parental interview.

RESULTS: Children with ADHD demonstrated significantly poorer olfactory identification ability compared to healthy controls (p < .01). A significant right nostril advantage for smell identification was evident in the control group (p < .01), whereas significant right nostril impairment was evident among the children with ADHD (p < .01).

CONCLUSION: The results provide the first evidence of olfactory identification deficits in children with ADHD. As such deficits implicate orbitofrontal regions, this finding is consistent with previous reports of prefrontal compromise in children with ADHD.

Karsz FR, Vance A, Anderson VA, Brann PG, Wood SJ, Pantelis C, Brewer WJ. Olfactory impairments in child attention-deficit/hyperactivity disorder. J Clin Psychiatry. 2008 Sep;69(9):1462-1468.