Oxyhemoglobin changes in the prefrontal cortex in response to cognitive tasks: a systematic review

Purpose of the study: the aim of this study was to synthesize PFC fNIRS outcomes on the effects of cognitive tasks compared to resting/baseline tasks in healthy adults from studies utilizing a pre/post design.

Material and methods: original research studies were searched from seven databases (MEDLINE, EMBASE, CENTRAL, CINAHL, SCOPUS, PEDro and PubMed). Subsequently, two independent reviewers screened the titles and abstracts followed by full-text reviews to assess the studies' eligibility.

Results: eleven studies met the inclusion criteria and had data abstracted and quality assessed. Methodology varied considerably and yet cognitive tasks resulted in the ΔO₂Hb increasing in 8 of the 11 and ΔHHb decreasing in 8 of 8 studies that reported this outcome. The cognitive tasks from 10 of the 11 studies were classified as “Working Memory” and “Verbal Fluency Tasks”.

Conclusions: although, the data comparison was challenging provided the heterogeneity in methodology, the results across studies were similar.     

Synovial chondromatosis of four compartments of the knee: medial and lateral tibiofemoral spaces,patellofemoral joint and proximal tibiofibular joint

A case of synovial chondromatosis of the proximal tibiofibular joint in addition to lateral and medial tibiofemoral spaces and patellofemoral joint has been presented.     

Prefabrication of bone by vascular induction: an experimental study in rabbits.

The various methods of prefabricating flaps include vascular induction through staged transfer; pretransfer delay, expansion, and grafting; the use of alloplastic materials; and tissue bioengineering. In this experimental study, vascular induction was used to provide an axial vascular pedicle to randomly nourished tissue. Twenty-six New Zealand rabbits, ages and weights ranging between 6 months-1 year and 1.5-3.5 kg, respectively, were used. The sex difference was not considered. The deep inferior epigastric artery and vein were used to carry blood and were placed into a segment of femur to prefabricate the bone. Four weeks later, the viability of the segment of bone prefabricated by new axial pedicle was shown by scintigraphic study, and the new axial pedicle was ready for free transfer.     

Cognitive impairment after unilateral hemispheric injury of congenital or adult origin.

OBJECTIVE: The purpose of this study was to assess and compare cognitive functioning in adults with unilateral hemispheric injury due to either congenital damage or an ischemic event in young adulthood. METHOD: Adults with cerebral palsy resulting from left hemispheric brain damage were compared with adults who had a unilateral stroke in either the left or the right hemisphere. Our primary interest was to determine the impact on hemispheric dominance as revealed by dichotic listening, a task that assesses the bias for preferential listening and processing of sounds. Performance also was determined on a language-related task (word finding) and a spatial task (dot localization). RESULTS: Scores on the Quick Neurological Screening Test indicated that all participants demonstrated significant neuromotor deficits, whereas scores on the Barthel Index indicated that the participants were functional in basic activities of daily living. On cognitive assessments, healthy control participants demonstrated a pronounced left-hemisphere dominance and right-ear advantage; participants with injury to the left hemisphere showed a strong shift toward a right-hemisphere and left-ear dominance. In particular, injury of congenital origin appeared to foster this neural reorganization and localization of language-related functions into the healthy hemisphere. This shift was associated with a deterioration of performance on both the language and the spatial tasks. CONCLUSION: The importance of appreciating subtle deficits after unilateral injury is important in therapy. The dichotic listening test may provide a simple and useful means for evaluating persistent unilateral brain dysfunction in the clinical setting.