Biomedical subjects

Gregory P Lee

Publications and source records attributed to Gregory P Lee.

At least 19 recordsLinked to original sources

PubMed2007

Bilateral stereotactic amygdalotomy for self-mutilation disorder. Case report and review of the literature.

Bilateral stereotactic amygdalotomy for the management of patients with severe aggressive behavior disturbances was first introduced by Hideki Narabayashi in 1961. Since then, more than 500 cases have been reported in scientific literature, with a variety of cited behavior improvement rates. The advances of psychopharmacology along with the existent skepticism of the medical community in regards to psychosurgery have resulted in a dramatic decrease in the number of amygdalotomies performed worldwide. In our current communication, we report a case of bilateral stereotactic amygdalotomy for a medically refractory self-mutilation disorder. We also review the pertinent literature with an emphasis on the selection of the most appropriate anatomical targets, the procedure-related complications and the outcomes of this occasionally helpful procedure.

Adult↗

PubMed2006

The Verbal IQ/Performance IQ discrepancy as a sign of seizure focus laterality in pediatric patients with epilepsy.

A large Verbal IQ (VIQ)/Performance IQ (PIQ) discrepancy has been viewed as a sign of lateralized brain dysfunction. The current study was conducted to determine if the presence of a large VIQ/PIQ discrepancy (15 points) would accurately predict laterality of seizure foci in pediatric patients with epilepsy. A discrepancy score (VIQ-PIQ) was calculated for 130 children (mean age=12.25) undergoing presurgical epilepsy evaluations. Patients were grouped on the basis of language mediation confirmed through the intracarotid amobarbital procedure. Large discrepancies were noted in 34% of the group with typical language and 24% of the children with atypical language organization. When present, this discrepancy accurately lateralized seizure focus for 79% of those with typical and 57% of those with atypical language organization. The presence of the discrepancy was unrelated to seizure control following surgery for the atypical language group. In the typical language group, 85% of children with discrepancies, but only 63% of children without discrepancies, achieved seizure control. Results suggest that the presence of a large discrepancy is not effective, by itself, in lateralizing seizure foci, but may contribute to refining predictions of surgical outcome.

Adolescent↗

PubMed2006

Structured cueing on a semantic fluency task differentiates patients with temporal versus frontal lobe seizure onset.

Patients with frontal lobe dysfunction (e.g., Huntington's disease) reportedly benefit more from cueing on measures of semantic fluency than do patients with damage to temporal lobe structures (e.g., Alzheimer's disease). This differential benefit from cueing suggests that different neurocognitive functions are impaired in these two groups. Patients with frontal lobe dysfunction are presumed to have difficulty with the executive aspects of this generative fluency task, whereas patients with temporal lobe impairment are limited by deficits in semantic memory. We studied the performance of patients with complex partial seizures of frontal or temporal lobe onset, as determined by video/EEG monitoring, on standard and cued measures of semantic fluency administered in a counterbalanced sequence across groups. These groups did not differ significantly in terms of age, education, gender, age at seizure onset, total number of antiepileptic drugs, or IQ, and all patients subsequently underwent surgery for intractable epilepsy. Patients with frontal lobe dysfunction (FL group) performed significantly worse than patients with temporal lobe impairment (TL group) on the standard semantic fluency paradigm (TL group: M=18.4, SD=4.7; FL group: M=11.1, SD=5.3), t(27)=-3.75, P<0.001. Nevertheless, results of an ANCOVA demonstrated that the FL group showed significantly greater performance improvement than the TL group when provided with a cued semantic fluency format, even after controlling for baseline differences in ability on the standard semantic fluency task (TL group: M=0.45, SD=3.8; FL M=9.4, SD=5.1), F(1,29)=12.37, P=0.002. These findings support previous research suggesting that frontal and temporal structures contribute uniquely to semantic generative fluency and suggest that using a combination of standard and cued semantic fluency tasks may help confirm localization of seizure onset in partial epilepsy by localizing the associated cognitive dysfunction.

Adult↗

PubMed2006

Outcome of patients undergoing gamma knife stereotactic radiosurgery for medically refractory idiopathic trigeminal neuralgia: Medical College of Georgia's experience.

Gamma knife radiosurgery represents an established treatment option for the management of medically refractory trigeminal neuralgia (TN). In our current communication we present our experience in radiosurgically treating patients with idiopathic TN. Over a period of 5 years, 77 patients underwent gamma knife radiosurgery. The patients were divided into 2 groups based on their previous surgical treatment. In the group of patients with no previous surgeries, the initial response rate was 92.4% (48/52 patients), while in the group with previous surgeries it was 84% (21/25 patients). The excellent outcome rates (complete pain relief with no pain medications) at the completion of 1, 2 and 3 years after treatment for the group with no previous surgeries were: 80.8% (42/52 patients), 69.2% (36/52 patients) and 53.8% (28/52 patients), respectively. The respective excellent outcome rates for the group of patients with previous surgeries were: 64% (16/25 patients), 44% (11/25 patients) and 12% (3/25 patients). The good outcome rates at the completion of 1, 2 and 3 years after treatment for the group with no previous surgeries were: 7.7% (4/52 patients), 11.5% (6/52 patients) and 19.2% (10/52 patients). The respective percentages of good outcome for the patients with previous surgery were: 12% (3/25 patients) at 1 year, 16% (4/25 patients) at 2 years and 32% (8/25 patients) at the completion of 3 years after treatment. The most commonly encountered complication in our series was the development of facial numbness. Our findings confirm previous reports that the presence of preceding surgical interventions represents a negative long-term outcome factor. However, gamma knife radiosurgery constitutes a safe and efficient minimally invasive treatment option for patients with idiopathic TN.

Adult↗

PubMed2006

Intracranial stimulation study of lateralization of affect.

As part of their evaluation for epilepsy surgery, 53 patients underwent stimulation of depth or subdural electrodes. Responses obtained from depth stimulation included motor responses at 34 sites, sensory responses at 114 sites, language alterations at 6 sites, and affective responses at 22 sites. Responses obtained from subdural stimulation included motor responses at 19 sites, sensory responses at 31 sites, speech alterations at 10 sites, and affective responses at 1 site. Of 23 affective responses, 21 were dysphoric responses of fear, a sense of dying, or unpleasantness with or without some type of experiential phenomenon. Dysphoric responses were statistically associated (P=0.01) with right-sided stimulation (N=18) as compared with left-sided stimulation (N=3) of mesial frontal, orbitofrontal, mesial temporal, and insular stimulation sites. Two euphoric responses occurred, one with left-sided and one with right-sided stimulation. No affective responses were obtained with convexity or neocortical stimulation.

Adolescent↗

PubMed2006

Autoimmunity in Alzheimer's disease as evidenced by plasma immunoreactivity against RAGE and Abeta42: complication of diabetes.

Features of autoimmunity have been associated with both Alzheimer's disease (AD) and with diabetes. In both diseases high levels of advanced glycation end products (AGEs) and their receptor (RAGE) have been detected in tissues and in the circulation. In addition high titers of antibodies directed against a RAGE-like peptide occur in the circulation. In this study we report the presence of auto-antibodies directed against RAGE and the cytotoxic amyloid peptide Abeta42 in plasma samples derived from four study groups. Anti-RAGE IgG titers were greatest in the AD-diabetic cohort. They were followed in decreasing order by the AD-non-diabetic cohort, the elderly diabetic cohort, and lastly by the control non-diabetic elderly cohort. The same profile of IgG differences was evident for the anti-Abeta42 titers. When all of the data were combined, there was a strong linear correlation between the RAGE and Abeta42 titers suggesting that the two peptides exist as a tight complex in plasma. Plasma IgG titers were not correlated with cognitive status except that AD and AD-diabetic participants were significantly cognitively impaired relative to the two non-AD groups. There also was no significant correlation between IgG titers and subject age, except that there was a trend for a negative slope for the AD participants and a positive slope for the control participants. In keeping with the human data, we also report that chemically-induced diabetes in rats was associated with high levels of AGEs, anti-RAGE-like IgGs, and anti-Abeta42-like IgGs. For non-diabetic rats, there was a clear age-dependency regarding the magnitude of the IgG levels. These data support the concept of an interrelationship between diabetes and AD. For both diseases one underlying contributing factor to cytotoxicity could be the development of an autoimmune response triggered by the presence of AGEs and amyloid peptides.

Aged↗

PubMed2005

Deteriorating outcomes after meniscal repair using the Meniscus Arrow in knees undergoing concurrent anterior cruciate ligament reconstruction: increased failure rate with long-term follow-up.

BACKGROUND: An increased awareness of the degenerative changes that occur in the knee after meniscectomy has led to efforts to salvage the injured meniscus. Numerous devices have been developed in an effort to provide the dual benefits of a durable meniscal repair and minimal invasiveness. HYPOTHESIS: The Meniscus Arrow is comparable to conventional inside-out suture repair in accomplishing long-term healing of meniscal tears. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: This study is an extended follow-up of an original series of 32 patients with outcomes analysis. All patients underwent meniscal repair with exclusive use of the arrow. All repairs were performed in the context of a concomitant anterior cruciate ligament reconstruction. Follow-up assessment included physical examination, arthrometry, the International Knee Documentation Committee instrument, and the Knee Disorders Subjective History visual analog scale. Intermediate follow-up at a mean of 2.3 years yielded a success rate of 90.6%. The mean follow-up in the present study has been extended to 6.6 years. RESULTS: The extended follow-up analysis revealed a substantial attrition in the success rate of this series of patients undergoing meniscal repair with the arrow. A 90.6% success rate at a mean follow-up of 2.3 years deteriorated to 71.4% at 6.6 years. CONCLUSION: This study provides the longest follow-up in the literature of any of the all-inside meniscal repair implants. The Meniscus Arrow demonstrated long-term meniscal healing rates inferior to those found in the literature for inside-out suture repair techniques.

Anterior Cruciate Ligament↗

PubMed2005

Traumatic articular-bursal fistula in a collegiate football player.

A collegiate football player suffered a direct blow to the distal quadriceps mechanism, resulting in a partial tear of the vastus medialis obliquus. Over time, he began to develop activity-related swelling of his prepatellar bursa. By 6 weeks after his injury, an area of swelling the size of a golf ball would rapidly develop with just 5 minutes of quadriceps exercises. Swelling would diminish within a few hours of rest. A magnetic resonance imaging examination suggested a fistula track from the articular space through the vastus medialis obliquus into the prepatellar bursal area. When prolonged rest did not improve his symptoms, he was taken to surgery. Arthroscopic visualization confirmed a traumatic fistula between the articular space and the prepatellar bursa, allowing free egress of fluid. A spinal needle was used to localize the fistula tract to allow this to be identified for an open, layered suture closure. An area of traumatic chondrosis on the medial side of the patella with loose chondral flaps was also debrided as the probable "fluid generator." The patient enjoyed a full recovery and was back to playing college football 10 weeks after surgery.

Adult↗

PubMed2005

Dimensions of the epilepsy foundation concerns index.

We performed principal component analysis (PCA) of the Epilepsy Foundation Concerns Index scale in 189 patients undergoing evaluation for epilepsy surgery. We identified a five-factor solution in which there were no varimax-rotated factors consisting of fewer than two questions. Factor 1 reflects affective impact on enjoyment of life, Factor 2 reflects general autonomy concerns, Factor 3 reflects fear of seizure recurrence, Factor 4 reflects concern of being a burden to one's family, and Factor 5 reflects a perceived lack of understanding by others. Multiple regression using the Quality of Life in Epilepsy--89 question version; Minnesota Multiphasic Personality Inventory--2; Wechsler Adult Intelligence Scale--third edition; and verbal and visual memory tests as predictors demonstrated a different pattern of association with the factor and summary scores. We conclude that the Epilepsy Foundation Concerns Index is multidimensional, and using a global score based on all items may mask specific concerns that may be relevant when applied to individual patients.

Adult↗

PubMed2005

Victoria symptom validity test performance in non-litigating epilepsy surgery candidates.

We report Victoria Symptom Validity Test (VSVT) performance in 120 epilepsy patients undergoing neuropsychological assessment as part of their evaluation as epilepsy surgery candidates. Patients were grouped according to their performance on hard VSVT stimuli. Scores of at least 21/24 on the hard VSVT items were classified as valid (n=86), scores of 18/24-20/24 were considered questionably valid (n=20), and scores of 17/24 and below were designated as invalid (n=14). Significant group effects were observed for WAIS-III Full Scale IQ, Verbal IQ, Performance IQ, Digit Span, Rey 3x5 Memory, Selective Reminding Recognition, and Complex Figure Immediate Recall; poorer cognitive scores were associated with lower VSVT scores. Age was also related to VSVT performance, with patients older that 40 years of age (16/42) more likely to fail the VSVT (i.e., hard scores < or = 20/24) than their younger counterparts (8/78) (p=.0006, Fisher's Exact Test). These results indicate that VSVT may identify cases of incomplete effort in patients being evaluated for strictly clinical purposes in which no external incentive to perform poorly has been identified, although the potential confound of low IQ on VSVT cannot be determined from this sample. Older patients also appear to be at increased risk for suboptimal performance, and may need additional encouragement or education regarding the need to perform to the best of their ability, and thereby maximize the likelihood of obtaining valid neuropsychological test results.

Adult↗

PubMed2005

Prediction of verbal memory decline after epilepsy surgery in children: effectiveness of Wada memory asymmetries.

PURPOSE: Differences in Wada memory performance after left and right amobarbital injection are powerful predictors of pre- to postoperative memory change among adult epilepsy patients after anterior temporal lobectomy. It is unknown, however, whether these Wada memory asymmetries apply to children who undergo focal cortical resection or to epilepsy surgery patients who undergo resection outside the temporal lobes. METHODS: To investigate these issues, Wada memory asymmetries and pre- to postoperative neuropsychological memory test performances were examined in 132 children who underwent some form of resective epilepsy surgery. Ninety-three (70%) children showed Wada memory asymmetries in the predicted direction (memory after injection ipsilateral to side of surgery better than memory after contralateral injection), and 39 (30%) did not. RESULTS: Children with Wada memory asymmetries showed significant improvement in verbal memory after surgery as compared with children without Wada memory asymmetries who showed significant verbal memory decline. This result was also obtained when individual cases were examined: 77% of children with Wada memory asymmetries in predicted direction showed no verbal memory decline after surgery, whereas 80% of children without asymmetries had lower postoperative verbal memory (passage recall) test scores. Wada memory asymmetries had no value in predicting postoperative changes in visual-spatial memory. CONCLUSIONS: Wada memory asymmetries may be used as one of the factors to assess risk for verbal memory decline after epilepsy surgery in children.

Adolescent↗

PubMed2004

Structural versus functional prediction of memory change following anterior temporal lobectomy.

Decline in recent memory function is a significant risk for patients undergoing anterior temporal lobectomy. We report a patient with a febrile seizure history, complex partial seizures arising from the left anterior temporal lobe, and MRI evidence suggesting left hippocampal sclerosis, all of which indicate a low likelihood of significant postoperative memory decline. However, high normal verbal memory on neuropsychological testing and bilaterally normal Wada memory scores indicated increased risk for postoperative memory decline. Following left anterior temporal lobectomy, the patient displayed a significant decline in verbal recent memory that affected school performance. Despite the worsening in memory, the patient reported a significant improvement in his self-reported quality-of-life perception, demonstrating that factors other than change in cognitive performance are related to whether a patient considers epilepsy surgery worthwhile. In the present case, behavioral measures were superior to structural measures in predicting cognitive change following surgery.

Adult↗

PubMed2004

Determinants of quality of life in epilepsy.

Although depression is associated with diminished quality of life (QOL) in epilepsy patients, the relative contributions of epilepsy-specific concerns, as well as clinical and cognitive variables of QOL, have not been simultaneously investigated. A comprehensive neuropsychological test battery including the Beck Depression Inventory (BDI), Epilepsy Foundation of America's (EFA) Concerns Index, MMPI-2, QOLIE-89, WAIS-III, and Selective Reminding was administered to 115 epilepsy surgery candidates with normal Full Scale IQs. Linear regression analyses were performed to identify significant predictor combinations of QOLIE-89 total score. Regression analysis demonstrated that depressive symptomatology, whether reflected by the BDI (R2=0.45) or Depression scale of the MMPI-2 (R2=0.36), was a robust individual QOL predictor. Seizure Worry from the EFA Concerns Index was nearly as effective as the BDI in predicting QOLIE-89 (R2=0.42). When the BDI and EFA Concerns Index were combined into the same regression, both factors continued to contribute significantly to the QOLIE-89 total score, with both variables accounting for 61% of the variance. Although patients who developed their seizures at an older age had poorer QOL and patients with higher educational levels reported higher QOL, neither factor was related to QOL after accounting for the effects of psychological variables and epilepsy-related concerns. Although quality of life has multiple determinants, symptoms of depression and seizure worry are the most important factors affecting QOL in patients with intractable epilepsy.

Adult↗

PubMed2004

Neural substrates of emotion as revealed by functional magnetic resonance imaging.

OBJECTIVES: To examine the brain circuitry involved in emotional experience and determine whether the cerebral hemispheres are specialized for positive and negative emotional experience. BACKGROUND: Recent research has provided a preliminary sketch of the neurologic underpinnings of emotional processing involving specialized contributions of limbic and cortical brain regions. Electrophysiologic, functional imaging, and Wada test data have suggested positive, approach-related emotions are associated with left cerebral hemisphere regions, whereas negative, withdrawal-related emotions appear to be more aligned with right hemisphere mechanisms. METHOD: These emotional-neural associations were investigated using functional magnetic resonance imaging in 10 healthy controls with 20 positively and 20 negatively valenced pictures from the International Affective Picture System in a counterbalanced order. Pictures were viewed within a 1.5 Telsa scanner through computerized video goggles. RESULTS: Emotional pictures resulted in significantly increased blood flow bilaterally in the mesial frontal lobe/anterior cingulate gyrus, dorsolateral frontal lobe, amygdala/anterior temporal regions, and cerebellum. Negative emotional pictures resulted in greater activation of the right hemisphere, and positive pictures caused greater activation of the left hemisphere. CONCLUSIONS: Results are consistent with theories emphasizing the importance of circuitry linking subcortical structures with mesial temporal, anterior cingulate, and frontal lobe regions in emotion and with the valence model of emotion that posits lateralized cerebral specialization for positive and negative emotional experience.

Adult↗

PubMed2003

Wada memory performance predicts seizure outcome after epilepsy surgery in children.

PURPOSE: Wada memory asymmetries were examined in children from four comprehensive epilepsy surgery centers who subsequently underwent epilepsy surgery to determine whether Wada memory performance could predict degree of seizure relief in children. METHODS: One hundred fifty-six children (between ages 5 and 16 years) with intractable epilepsy underwent Wada testing before resective epilepsy surgery (93 within the left hemisphere, and 63 within the right hemisphere). Memory stimuli were presented soon after intracarotid amobarbital injection, and recognition memory for the items was assessed after return to neurologic baseline. Eighty-eight children underwent unilateral temporal lobe resection, and 68 had extratemporal lobe resections. One hundred four (67%) children were seizure free (Engel class I), and 52 (33%) were not seizure free (Engel classes II-IV) at follow-up (mean follow-up interval, 2.3 years). RESULTS: Seizure-free children recalled 19.3% more Wada memory items after ipsilateral injection than did non-seizure-free children (p = 0.008). If analysis was restricted to youngsters with temporal lobectomies (TLs), seizure-free children recalled 27.7% more items after ipsilateral injection than did non-seizure-free TL children (p = 0.004). With regard to individual patient prediction, 75% of children who had memory score asymmetries consistent with the seizure focus were seizure free. In contrast, only 56% of children whose memory score asymmetries were inconsistent with the seizure focus were seizure free (p = 0.01). CONCLUSIONS: Results suggest that Wada memory performance asymmetries are related to the degree of seizure relief after epilepsy surgery in children and adolescents.

Adolescent↗

PubMed2003

A 10-year experience with magnetic source imaging in the guidance of epilepsy surgery.

Magnetic source imaging (MSI) of interictal epileptiform dipoles was studied in 100 epilepsy surgery candidates. Sixty underwent surgery. MSI epileptiform data were classified as focal, regional, multifocal, scattered or none. Resections of MSI epileptiform foci were classified as extensive (EXT) versus partial or none (P/N). MSI interictal epileptiform dipoles were found in 22 of 27 anterior temporal (ATL) cases, and in 31 of 33 extratemporal (XMT) cases. Of 10 EXT ATL cases, 5 (50%) were seizure free (SF). Of 12 P/N ATL cases, 7 (58%) were SF. Of 10 nonlesional EXT XMT resections, 8 (80%) were SF. Of 10 nonlesional P/N XMT resections, 1 (10%) was SF. Neither focality of MSI data or spatial agreement of electrographic and MSI data significantly affected outcomes.

Epilepsy↗

PubMed2003

Effect of extracorporeal shock waves on calcaneal bone spurs.

In a prospective study of 435 patients with chronic proximal plantar fasciitis, 283 (65%) had an inferior calcaneal bone spur of variable size evident prior to treatment with electrohydraulic high-energy extracorporeal shock waves (ESW). This included 308 patients who received extracorporeal shock wave treatments and 127 placebo (sham control) patients. At both initial (3 months) and final (12 months) evaluations after receiving ESW, no patient who received shock wave applications had significant disappearance or change in the radiographic appearance of the heel spur. Clinical outcome after ESW was satisfactory in 168 patients (82%) with a radiographically demonstrable inferior heel spur and in 81 patients (79%) without such a heel spur. The results showed no correlation between the presence or absence of the heel spur and the eventual treatment outcome.

Chronic Disease↗

PubMed2003

Impact of the changing health care environment on fieldwork education: perceptions of occupational therapy educators.

To investigate how clinical fieldwork educators and academic fieldwork coordinators view the impact of the changing health care environment on student fieldwork education, current practice, and future of the profession, a 48-item questionnaire assessing the influence of recent changes in the health care system on fieldwork education was sent to 125 occupational therapy fieldwork educators and coordinators (response rate 62.4%). Differences between fieldwork educators and coordinators were analyzed statistically using nonparametric methods. Alpha level was set at p < 0.01 for all statistical comparisons. Fieldwork educators and coordinators agreed productivity expectations, number of hours worked, and time spent in documentation have increased, while job security, time for continuing education, and quality of patient care under the current reimbursement system have decreased, but diverged on several other issues. Fieldwork educators believed reimbursement issues did not affect their ability to accept fieldwork students, whereas academic coordinators believed declining reimbursement had negatively affected fieldwork educators' ability to accept students. Factors thought to facilitate the fieldwork shortage included cost reductions, changes in reimbursement, and increased productivity demands on clinicians.

Allied Health Personnel↗