The use of the Rey 15-Item Test and recognition trial to evaluate noncredible effort after pediatric mild traumatic brain injury

The Rey 15-Item Test (FIT) is a performance validity test commonly used in adult neuropsychological assessment. FIT classification statistics across studies have been variable, so a recognition trial was created to enhance the measure (Boone, K. B., Salazar, X., Lu, P., Warner-Chacon, K., & Razani, J. (2002). The Rey 15-Item recognition trial: A technique to enhance sensitivity of the Rey 15-Item Memorization Test. Journal of Clinical and Experimental Neuropsychology, 24(5), 561–573.). The current study assessed the utility of the FIT and recognition trial in a pediatric mild traumatic brain injury sample (N = 319, M = 14.57 years). All participants were administered the FIT and recognition trial as part of an abbreviated clinical neuropsychological evaluation. Failure on the Medical Symptom Validity Test was used as the criterion for noncredible effort. Fifteen percent of the sample met the criterion. The traditional adult cutoff score of <9 on the FIT recall trial yielded excellent specificity (98%), but very poor sensitivity (12%). When the recognition trial was utilized, a total score of <26 resulted in the best combined cutoff score (sensitivity = 55%, specificity = 91%). Results indicate that the FIT with recognition trial may be useful in the assessment of noncredible effort with children and adolescents, at least among relatively high-functioning populations.     

Experimental observation of a theoretically predicted nonlinear sleep spindle harmonic in human EEG

Objective: To investigate the properties of a sleep spindle harmonic oscillation previously predicted by a theoretical neural field model of the brain.     

Bone Flap Necrosis After Decompressive Hemicraniectomy for Malignant Middle Cerebral Artery Infarction

Background

Autologous bone flap reinsertion follows as a second surgical intervention after decompressive craniectomy in patients with malignant middle cerebral artery (MCA) infarction. In addition to surgery-related short-term complications, aseptic resorption of the reimplanted bone flap is a possible long-term problem which has not yet been sufficiently elucidated in these patients.

Methods

A total of 109 patients who had undergone decompressive hemicraniectomy for malignant MCA infarction in our institution between September 1994 and December 2011 were included in the study. Clinical and radiological findings were retrieved retrospectively. Aseptic bone necrosis was classified into two categories based on computer tomographic features.

Results

A total of 76 patients received their own cryoconserved bone flap (mean age 54.34 ± 10.73 years; 49 males). The overall short-term complication rate was 9.2 %. Bone flap necrosis occurred in 26 patients (22.8 %) with 7 flaps showing signs of surgically relevant type II necrosis after a median time of 14 months (interquartile range [IQR] 4–22).

Conclusions

There is a noticeable complication rate in patients undergoing bone flap reinsertion after hemicraniectomy due to malignant MCA infarction. Aseptic bone necrosis represents a significant complication during long-term follow-up. The pathophysiological mechanisms remain unclear and more efforts should be undertaken to understand and possibly prevent this complication in these patients.