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1.  Acceleration-Deceleration Sport-Related Concussion: The Gravity of It All 
Journal of Athletic Training  2001;36(3):253-256.
To discuss a newtonian physics model for understanding and calculating acceleration-deceleration forces found in sport-related cerebral concussions and to describe potential applications of this formula, including (1) an attempt to measure the forces applied to the brain during acceleration-deceleration injuries, (2) a method of accruing objective data regarding these forces, and (3) use of these data to predict functional outcome, such as neurocognitive status, recovery curves, and return to play.
Mild concussion in sports has gained considerable attention in the last decade. Athletic trainers and team physicians have attempted to limit negative outcomes by gaining a better understanding of the mechanisms and severity of mild head injuries and by developing meaningful return-to-play criteria. Mild head injury in sports has become an even greater area of focus and concern, given the negative neurobehavioral outcomes experienced by several recent high-profile professional athletes who sustained repeated concussions. Applying the principles of physics to characterize injury types, injury severity, and outcomes may further our development of better concussion management techniques and prevention strategies.
We describe the search for models to explain neuronal injury secondary to concussion and provide an exploratory method for quantifying acceleration-deceleration forces and their relationship to severity of mild head injury. Implications for injury prevention and reduction of morbidity are also considered.
PMCID: PMC155415  PMID: 12937493
mild head injury; physics; athletic injury; axonal injury; whiplash
2.  Out-of-body experiences associated with seizures 
Alterations of consciousness are critical factors in the diagnosis of epileptic seizures. With these alterations in consciousness, some persons report sensations of separating from the physical body, experiences that may in rare cases resemble spontaneous out-of-body experiences. This study was designed to identify and characterize these out-of-body-like subjective experiences associated with seizure activity. Fifty-five percent of the patients in this study recalled some subjective experience in association with their seizures. Among our sample of 100 patients, 7 reported out-of-body experiences associated with their seizures. We found no differentiating traits that were associated with patients' reports of out-of-body experiences, in terms of either demographics; medical history, including age of onset and duration of seizure disorder, and seizure frequency; seizure characteristics, including localization, lateralization, etiology, and type of seizure, and epilepsy syndrome; or ability to recall any subjective experiences associated with their seizures. Reporting out-of-body experiences in association with seizures did not affect epilepsy-related quality of life. It should be noted that even in those patients who report out-of-body experiences, such sensations are extremely rare events that do not occur routinely with their seizures. Most patients who reported out-of-body experiences described one or two experiences that occurred an indeterminate number of years ago, which precludes the possibility of associating the experience with the particular characteristics of that one seizure or with medications taken or other conditions at the time.
PMCID: PMC3923147  PMID: 24592228
epilepsy; seizures; out-of-body experience; autoscopy; near-death experience
3.  Neuropsychological outcomes after Gamma Knife radiosurgery for mesial temporal lobe epilepsy: a prospective multicenter study 
Epilepsia  2011;52(5):909-916.
To assess outcomes of language, verbal memory, cognitive efficiency and mental flexibility, mood, and quality of life (QOL) in a prospective, multicenter pilot study of Gamma Knife radiosurgery (RS) for mesial temporal lobe epilepsy (MTLE).
RS, randomized to 20 Gy or 24 Gy comprising 5.5-7.5mL at the 50% isodose volume, was performed on mesial temporal structures of patients with unilateral MTLE. Neuropsychological evaluations were performed at preoperative baseline, and mean change scores were described at 12 and 24 months postoperatively. QOL data were also available at 36 months.
Key Findings
30 patients were treated and 26 were available for the final 24 month neuropsychological evaluation. Neither language (Boston Naming Test), verbal memory (California Verbal Learning Test and Logical Memory subtest of the Wechsler Memory Scale-Revised), cognitive efficiency and mental flexibility (Trail Making Test), nor mood (Beck Depression Inventory) differed from baseline. QOL scores improved at 24 and 36 months, with those patients attaining seizure remission by month 24 accounting for the majority of the improvement.
The serial changes in cognitive outcomes, mood, and QOL are unremarkable following RS for MTLE. RS may provide an alternative to open surgery especially in those patients at risk of cognitive impairment or who desire a noninvasive alternative to open surgery.
PMCID: PMC3519361  PMID: 21426323
epilepsy surgery; radiosurgery; verbal memory; language; depression; quality of life
4.  Neuropsychological dysfunction in patients with end-stage pulmonary disease: lung transplant evaluation 
There has been a relative absence of studies that have examined the neuropsychological profiles of potential lung transplant candidates. Neuropsychological data are presented for 134 patients with end-stage pulmonary disease who were being evaluated as potential candidates for lung transplantation. Neuropsychological test results indicated that a significantly greater proportion of the patients exhibited impaired performances on a number of Selective Reminding Test (SRT) tasks as compared to the expected population frequency distributions for these measures. The highest frequencies of impairment were observed on the SRT’s Immediate Free Recall (46.43%), Long-term Retrieval (41.67%), and Consistent Long-term Retrieval (51.19%) variables. On the Minnesota Multiphasic Personality Inventory-2 (MMPI-2)/Minnesota Multiphasic Personality Inventory-Adolescent (MMPI-A), patients’ mean clinical profile revealed elevations on Scales 1 (Hypochondriasis) and 3 (Conversion Hysteria). This profile indicated that they were experiencing an array of symptomatology ranging from somatic complaints to lethargy and fatigue, and that they may have been functioning at a reduced level of efficiency. Findings are discussed in light of patients’ end-stage pulmonary disease and factors possibly contributing to their neuropsychological test performances. Implications for clinical practice and future research are also provided.
PMCID: PMC3219058  PMID: 14591451
Neuropsychology; Neurocognitive; Pulmonary disease; End-stage; Lung transplant
5.  Neurocognitive Differences Between Drivers with Type 1 Diabetes with and without a Recent History of Recurrent Driving Mishaps 
A subset of drivers with type 1 diabetes mellitus (T1DM) may be at significant risk of hypoglycemia-related driving collisions and moving vehicle violations due to acute and chronic neurocognitive impairment. The present study compared drivers with T1DM with and without a recent history of multiple driving mishaps on a neurocognitive battery during euglycemia, progressive mild hypoglycemia, and recovery from hypoglycemia, to determine whether neurocognitive measures differentiate the two risk groups. We hypothesized that drivers with a history of multiple recent hypoglycemia-related driving mishaps would demonstrate greater psychomotor slowing, both during hypoglycemia and euglycemia.
Study design
Partcipants were 42 adults with T1DM and were assigned to one of two groups: those reporting no driving mishaps in the last year (−History) and those reporting two or more (+History).Neurocognitive testing was conducted before and repeated during a hyper-insulinemic clamping procedure.
Not surprisingly, all drivers demonstrated a decrease in functioning across all neurocognitive tasks during hypoglycemia. However, in contrast to the common belief that neurocognitive functions return slowly and gradually following hypoglycemia, baseline neurocognitive functioning immediately recovered upon return of BG to euglycemia for all subjects. Between-group analyses revealed that subjects with a recent history of driving mishaps consistently demonstrated poorer performance on tasks measuring working memory.
Working memory is a potential neurocognitive indicator that may help differentiate adults with T1DM with and without a history of driving mishaps, predict future risk for driving mishaps, and provide targeted intervention programs to address this critical public health issue.
PMCID: PMC2993428  PMID: 21127720
type 1 diabetes mellitus; driving; neuropsychology; hypoglycemia
6.  Neuropsychological dysfunction in patients suffering from end-stage chronic obstructive pulmonary disease 
Few studies have examined the neuropsychological sequelae associated with end-stage pulmonary disease. Neuropsychological data are presented for 47 patients with end-stage chronic obstructive pulmonary disease (COPD) who were being evaluated as potential candidates for lung transplantation. Although patients exhibited a diversity of neurocognitive deficits, their highest frequencies of impairment were found on the Selective Reminding Test (SRT). Specifically, over 50% of the patients completing the SRT exhibited impaired immediate free recall and consistent long-term retrieval deficits, while more than 44% of these individuals displayed deficient long-term retrieval. Deficient SRT long-term storage strategies, cued recall, and delayed recall were exhibited by between 26% and 35% of these patients, while more than 32% of this sample displayed elevated numbers of intrusion errors. Over 31% of the patients completing the Wisconsin Card Sorting Test (WCST) failed to achieve the expected number of categories on this measure, while more than 23% of these individuals demonstrated elevated numbers of perseverative errors and total errors. Clinically notable frequencies of impairment (greater than 20% of the sample) were also found on the Trail Making Test (TMT): Part B and the Wechsler Memory Scale-R (WMS-R) Visual Reproduction II subtest. Minnesota Multiphasic Personality Inventory-2 (MMPI-2) personality assessments indicated that patients were experiencing a diversity of somatic complaints and that they may have been functioning at a reduced level of efficiency. These findings are discussed in light of patients’ end-stage COPD and factors possibly contributing to their neuropsychological test performances. Implications for clinical practice and future research are also included.
PMCID: PMC2714268  PMID: 14589783
Neuropsychological dysfunction; Chronic obstructive pulmonary disease; Lung transplantation

Results 1-7 (7)