Tuesday, September 11, 2012

A systematic review of amnestic and non-amnestic mild cognitive impairment induc

Tannenbaum C, Paquette A, Hilmer S, Holroyd-Leduc J, Carnahan R; Drugs & Aging 29 (8), 639-58 (Aug 2012)A systematic review of amnestic and non-amnestic mild cognitive impairment induced by anticholinergic, antihistamine, GABAergic and opioid drugsCarnahan R; Drugs & Aging 29 (8), 639-58 (Aug 2012


Background: Mild cognitive deficits are experienced by 18% of community-dwelling older adults, many of whom do not progress to dementia. The effect of commonly used medication on subtle impairments in cognitive function may be under-recognized. Objective: The aim of the review was to examine the evidence attributing amnestic or non-amnestic cognitive impairment to the use of medication with anticholinergic, antihistamine, GABAergic or opioid effects. Methods: MEDLINE and EMBASE were searched for randomized, double-blind, placebo-controlled trials of adults without underlying central nervous system disorders who underwent detailed neuropsychological testing prior to and after oral administration of drugs affecting cholinergic, histaminergic, GABAergic or opioid receptor pathways. Seventy-eight studies were identified, reporting 162 trials testing medication from the four targeted drug classes. Two investigators independently appraised study quality and extracted relevant data on the occurrence of amnestic, non-amnestic or combined cognitive deficits induced by each drug class. Only trials using validated neuropsychological tests were included. Quality of the evidence for each drug class was assessed based on consistency of results across trials and the presence of a dose-response gradient. Results: In studies of short-, intermediate- and long-acting benzodiazepine drugs (n = 68 trials), these drugs consistently induced both amnestic and non-amnestic cognitive impairments, with evidence of a dose-response relationship. H(1)-antihistamine agents (n = 12) and tricyclic antidepressants (n = 15) induced non-amnestic deficits in attention and information processing. Non-benzodiazepine derivatives (n = 29) also produced combined deficits, but less consistently than benzodiazepine drugs. The evidence was inconclusive for the type of cognitive impairment induced by different bladder relaxant antimuscarinics (n = 9) as well as for narcotic agents (n = 5) and antipsychotics (n = 5). Among healthy volunteers>60 years of age, low doses of commonly used medications such as lorazepam 0.5 mg, oxybutynin immediate release 5 mg and oxycodone 10 mg produced combined deficits. Conclusion: Non-amnestic mild cognitive deficits are consistently induced by first-generation antihistamines and tricyclic antidepressants, while benzodiazepines provoke combined amnestic and non-amnestic impairments. Risk-benefit considerations should be discussed with patients in order to enable an informed choice about drug discontinuation or substitution to potentially reverse cognitive adverse effects.


Tuesday, July 3, 2012


celebrities in cognitive neuroscience

Sunday, February 19, 2012

evolutionary: brain size homo sapiens not largest

Brains of nonhuman hominids that had greater proportional brain size than homosapiens include

1. Boskops 1900 cc brains
2.  Fossils found in Shkul caves in Qafzeh, Israel; in Wadjak in Indonesia; Fish Hock of S Africa all were larger than humans' 1300 cc but not as large as the Boskops.

Tuesday, February 7, 2012

Counting-backward test for executive function in idiopathic normal pressure hydr

Kanno S, Saito M, Hayashi A, Uchiyama M, Hiraoka K, Nishio Y, Hisanaga K, Mori E; Acta Neurologica Scandinavica (Jan 2012)

OBJECTIVES: The aim of this study was to develop and validate a bedside test for executive function in patients with idiopathic normal pressure hydrocephalus (INPH). MATERIALS AND METHODS: Twenty consecutive patients with INPH and 20 patients with Alzheimer's disease (AD) were enrolled in this study. We developed the counting-backward test for evaluating executive function in patients with INPH. Two indices that are considered to be reflective of the attention deficits and response suppression underlying executive dysfunction in INPH were calculated: the first-error score and the reverse-effect index. Performance on both the counting-backward test and standard neuropsychological tests for executive function was assessed in INPH and AD patients. RESULTS: The first-error score, reverse-effect index and the scores from the standard neuropsychological tests for executive function were significantly lower for individuals in the INPH group than in the AD group. The two indices for the counting-backward test in the INPH group were strongly correlated with the total scores for Frontal Assessment Battery and Phonemic Verbal Fluency. The first-error score was also significantly correlated with the error rate of the Stroop colour-word test and the score of the go/no-go test. In addition, we found that the first-error score highly distinguished patients with INPH from those with AD using these tests. CONCLUSION: The counting-backward test is useful for evaluating executive dysfunction in INPH and for differentiating between INPH and AD patients. In particular, the first-error score may reflect deficits in the response suppression related to executive dysfunction in INPH.