Hippocampus and amygdala volumes in a random community-based sample of 60–64 year olds and their relationship to cognition

Reduced volumes of the hippocampus (HC) and amygdala (AG) are potential biomarkers for Alzheimer's disease (AD) and other neuropsychiatric disorders. Published studies on HC and AG volumes suffer from methodological limitations, and a valid and reliable normative database does not exist. This study aimed to establish a database of HC and AG volumes from a large community sample of participants 60–64 years old and relate them to cognition. A total of 452 randomly selected participants (from 622 approached) were retained in the study (238 males, 214 females), and all received brain MRI scans, as well as cognitive and physical assessments. HC and AG volumes were estimated from manual tracings on T1-weighted images, and intracranial volume (ICV) was obtained from an automated program. In both sexes, right hippocampi were larger than left, while left amygdalae were larger than right. The only correlation to remain significant after normalization was left HC volume and percent retention of a word list in females. This study provides a HC and AG volumetrics database and describes its relationship with cognitive performance in a representative sample using a standard methodology that will be a reference for future studies. It will therefore have clinical applicability in early AD and other disorders.     

Evaluation of QUADAS, a tool for the quality assessment of diagnostic accuracy studies

Background  

In clinical trials, both unequal randomization design and sequential analyses have ethical and economic advantages. In the single-stage-design (SSD), however, if the sample size is not adjusted based on unequal randomization, the power of the trial will decrease, whereas with sequential analysis the power will always remain constant. Our aim was to compare sequential boundaries approach with the SSD when the allocation ratio (R) was not equal.     

The distribution of arachidonic acid in plasma and tissues of patients near term undergoing elective or emergency Caesarean section

The distribution of arachidonic acid in both the free and the bound state was measured in the maternal circulation, the fetal circulation and tissues within the pregnant uterus in 16 patients undergoing Caesarean section. Half of the patients had an elective Caesarean section and half had a Caesarean section during labour. No differences in arachidonic acid concentrations were found between the maternal or fetal circulations in women having elective Caesarean section and those having a Caesarean section in labour. The total and bound values of arachidonic acid in myometrium were higher in patients undergoing Caesarean section in labour. There was also an increased amount of arachidonic acid when expressed as an arachidonic acid/palmitic acid ratio between the fetal circulation and the maternal circulation, suggesting an active transport mechanism for arachidonic acid across the placenta. Levels of free arachidonic acid were in microgram quantities in both plasma and tissues, suggesting that the availability of free arachidonic acid was not the limiting factor in prostaglandin production.     

Multiple spin-echo magnetic resonance imaging

Spin-echo magnetic resonance (MR) imaging detects a variety of pathologic states with great sensitivity. A technique for producing multiple spin-echo images in multisection operation is presented. This method of intensity-image acquisition is compared with retrospective intensity-image synthesis from routine data sets. Both yield long echo time (TE) images with similar image contrast and comparable and often increased diagnostic utility. Technical and clinical considerations are addressed, including signal-to-noise levels, flow effects, and patient throughput.     

Near-hanging as presenting to hospitals in Queensland: recommendations for practice

Near-hanging is an increasing presentation to hospitals in Australasia. We reviewed the clinical management and outcome of these patients as they presented to public hospitals in Queensland. A retrospective clinical record audit was made at five public hospitals between 1991 and 2000. Of 161 patients enrolled, 82% were male, 8% were indigenous and 10% had made a previous hanging attempt. Chronic medical illnesses were documented in 11% and previous psychiatric disorders in 42%. Of the 38 patients with a Glasgow Coma Scale score (GCS) of 3 on arrival at hospital, 32% returned to independent living and 63% died. Fifty-two patients received CPR, of whom 46% had an independent functional outcome. Independent predictors of mortality were a GCS on hospital arrival of 3 (AOR 150, CI 95% 12.4-1818, P<0.001), taking plain X-rays of the cervical spine (AOR 0.06, CI 95% 0.004-0.97, P=0.047) and contact with the ground (AOR 0.03, CI 95% 0.002-0.62, P=0.02). Only 66% had imaging of the cervical spine performed with other imaging performed infrequently. There were three laryngeal, two hyoid bone and three cervical spine injuries and one carotid dissection. The number of cervical spine X-rays required to find a significant cervical spine fracture was 54. Near-hanging presenting to hospital with a poor conscious state or even cardiac arrest can have a favourable clinical outcome. Radiological investigations are infrequently performed despite a low GCS precluding early accurate assessment. Given the general favourable outcome, an aggressive approach to searching for correctable injuries is recommended.