Biomedical subjects

Roy C Martin

Publications and source records attributed to Roy C Martin.

16 recordsLinked to original sources

PubMed2007

Structural and functional neuroimaging correlates of depression in temporal lobe epilepsy.

Depression is commonly experienced among persons with temporal lobe epilepsy (TLE). Although evidence exists implicating dysfunction of distributed neural structure and circuitry among depressed persons without epilepsy, little is known regarding the neural correlates of depression in TLE. We examined the relationship between self-reported depression severity and both structural MRI volumetry and [(18)F]fluorodeoxyglucose positron emission tomography (PET)-measured resting metabolism of the amygdala and hippocampus of 18 patients with TLE. Significant positive relationships were noted between right and left amygdala volumes and depression. No other significant relationships were observed between amygdala PET measures, hippocampal volumes, or hippocampal PET measures and degree of depressive symptomatology. These findings indicate that both right and left amygdala volumes are associated with depression severity among persons with TLE. Future studies examining the potential role of extended neural regions may clarify the observed structural relationship between depressive symptoms and the amygdala.

Adolescent↗

PubMed2006

Medical decision-making abilities in older adults with chronic partial epilepsy.

Little is known about the medical decision-making abilities of older adults with chronic partial epilepsy, although these patients are often faced with medical decisions that impact their health care. Twenty-one older adults with epilepsy and 21 healthy older adults completed the Capacity to Consent to Treatment Instrument (CCTI) and Dementia Rating Scale II (DRS-II). Older adults with epilepsy performed significantly below controls on the CCTI standards Evidencing Choice, Appreciation, and Understanding and the DRS-II Total Score. DRS-II was positively associated with performance on the standards Appreciation and Understanding. Number of antiepileptic drugs, duration of epilepsy, and age at seizure onset were related to performance on Understanding. Older adults with epilepsy demonstrated deficits in their capacity to give informed consent for medical treatment that appear to be associated with cognition and seizure variables. Physicians should consider the decisional abilities of their older adult patients with epilepsy when presenting treatment options.

Aged↗

PubMed2006

Inter-identity amnesia in dissociative identity disorder: a simulated memory impairment?

BACKGROUND: Although included in the current edition of the DSM, there does not seem to be consensus among mental health professionals regarding the diagnostic status and scientific validity of dissociative identity disorder (DID). This study was aimed at the detection of simulation of inter-identity amnesia in DID. METHOD: A sample of 22 DID patients was included, together with a matched control sample of subjects instructed to simulate inter-identity amnesia, a guessor group that had no knowledge of the stimulus material and a normal control group. A multiple-choice recognition test was included. The rate of incorrect answers was determined. Moreover, the specific simulation strategy used was examined by providing subjects with a range of choices that varied in extent of disagreement with the correct answer and determining whether plausible or implausible answer alternatives were selected. RESULTS: On the recognition test DID patients selected incorrect answers above chance like simulators. Patients thus seem to use their knowledge of the correct answer in determining their given answer. They were not characterized by a well-thought-out simulating behaviour style, as indicated by the differences in selection of specific answer alternatives found between patients and simulators. CONCLUSIONS: DID patients were found not to be characterized by an actual memory retrieval inability, in contrast to their subjective reports. Instead, it is suggested that DID may more accurately be considered a disorder characterized by meta-memory problems, holding incorrect beliefs about their own memory functioning.

Adult↗

PubMed2006

Declining medical decision-making capacity in mild AD: a two-year longitudinal study.

This is a report of a two-year longitudinal study comparing healthy older adult subjects (n = 15) and mild Alzheimer's disease (AD) patients (n = 20) using an objective performance measure of medical decision-making capacity (MDC). Capacity to consent to medical treatment was measured using the Capacity to Consent to Treatment Instrument (CCTI). The CCTI is a psychometric measure that tests MDC using a series of four core capacity standards: S1 (evidencing/communicating choice), S3 (appreciating consequences), S4 (providing rational reasons), and S5 (understanding treatment situation), and one experimental standard [S2] (making the reasonable treatment choice). For each standard, mild AD patients were assigned one of three capacity outcomes (capable, marginally capable, or incapable) based on cut-off scores derived from control group performance. At baseline, mild AD patients performed equivalently with controls on simple standards of evidencing a choice (S1) and making the reasonable choice ([S2]), but significantly below controls on complex standards of appreciation, reasoning, and understanding (S3, S4, and S5) (p < 0.02). Control performance was stable over time on all capacity standards. At one-year follow-up, the mild AD group did not show significant decline from baseline on any capacity standard. However, at two-year follow-up the mild AD group showed significant declines from baseline on the three complex standards (S3, S4, and S5) (p < 0.02), and a trend on one of the simple standards (S1). Over the two-year period, the proportion of marginally capable and incapable outcomes in the AD group increased substantially for four of the five standards (S1, S3, S4, and S5). Performance on [S2] remained stable over time in the AD group.We conclude that mild AD patients have impaired MDC at baseline, and demonstrate significant additional decline on complex consent abilities of appreciation, reasoning, and understanding over a two-year period. AD patients also show emerging impairment on the simple consent ability of evidencing choice at two-year follow-up. Capacity outcome data reflect similar declines over time for these four consent standards. The findings suggest the value of early assessment and regular monitoring at two-year intervals of MDC in patients with mild AD.

Aged↗

PubMed2005

Older adults with epilepsy demonstrate cognitive impairments compared with patients with amnestic mild cognitive impairment.

Little is known about the cognitive effects of chronic epilepsy in older adults. To better characterize cognitive impairment in seniors with epilepsy, we compared cognitive performance of 26 seniors with epilepsy with that of 26 well-matched patients with mild cognitive impairment (MCI) and 26 well-matched healthy older adults. Participants completed neuropsychological testing with the Dementia Rating Scale (DRS), Logical Memory, and CFL Word Fluency. There were no significant demographic group differences, although seniors with epilepsy had higher self-reported depression. Seniors with epilepsy performed below controls on virtually all neuropsychological tests, and performed below patients with MCI on DRS Total score, Initiation/Perseveration, and CFL Fluency. Seniors with epilepsy on antiepileptic drug (AED) polytherapy had the most severe cognitive deficits, whereas seniors with epilepsy on AED monotherapy were comparable to cholinesterase inhibitor-naïve patients with MCI. This study emphasizes the clinical importance of cognitive impairment in seniors with epilepsy and highlights the need for future studies addressing causes and treatment of cognitive impairment.

Age Factors↗

PubMed2005

Dynamic brain activation patterns for face recognition: a magnetoencephalography study.

The present study used magnetoencephalography (MEG) to investigate the spatiotemporal profile of neurophysiological activity associated with recognition of recently encountered human faces in seventeen healthy right-handed adults. Activity sources modeled as instantaneous equivalent current dipoles were found in ventral occipito-temporal regions during the early stages of stimulus processing and in lateral temporal cortices during later stages. Hemispheric asymmetries in regional activity were restricted to ventral occipitotemporal areas. The magnitude of magnetic flux originating in these regions was greater in the right hemisphere during the first 350 ms post-stimulus onset. In addition, the duration of neurophysiological activity was greater in the right hemisphere after 600 ms post-stimulus onset. The results indicate right hemisphere predominance in the degree of engagement of neurophysiological processes involved in both the pre- and post-recognition phases of face processing.

Adolescent↗

PubMed2005

Cognitive functioning in community dwelling older adults with chronic partial epilepsy.

PURPOSE: To examine cognitive functioning in community-dwelling older adults with chronic partial epilepsy and demographically matched healthy older adults. METHODS: Standardized measures of neurocognitive function were collected as part of an ongoing study investigating health-related quality-of-life issues in older adults with epilepsy. Cognitive tests consisted of the Mattis Dementia Rating Scale (subscales include attention, initiation/perseveration, construction, conceptualization, memory), Logical Memory subtest from the WMS-III (immediate and delayed recall scores), and word fluency. Mood was measured with the Geriatric Depression Scale. Older adults with epilepsy (n=25) and healthy older adults (n=27) completed testing. All participants were at least 60 years old, living independently in the community, and had no history of drug/alcohol abuse or life-threatening medical conditions. All older adults with epilepsy had been diagnosed as having medically intractable partial complex seizures, including those with histories of secondary generalization. RESULTS: Older adults with epilepsy demonstrated impairments across all cognitive measures compared with the healthy controls. Seizure onset (age) and seizure duration (years) were not statistically associated with neurocognitive function or self-reported mood. Older adults with epilepsy who were receiving antiepileptic drug (AED) polytherapy (n=11) displayed worse performance on the attention, initiation/perseveration, and memory subscales of the DRS and Logical Memory delayed recall score compared with those older adults with epilepsy receiving monotherapy (n=14). The number of AEDs taken was not associated with seizure frequency. CONCLUSIONS: Negative effects on cognitive function are experienced by older adults with chronic partial epilepsy. AED polytherapy may increase the risk for negative cognitive dysfunction.

Affect↗

PubMed2004

Self-report of cognitive abilities in temporal lobe epilepsy: cognitive, psychosocial, and emotional factors.

Self-report of cognitive functioning using the Multiple Abilities Self-Report Questionnaire (MASQ) was examined in 57 left (LTLE) and 36 right (RTLE) temporal lobe epilepsy patients. The MASQ is a 38-item self-report measure assessing five domains of self-perceived cognitive functioning: Language, Visual-Perceptual Abilities, Verbal Memory, Visual-Spatial Memory, and Attention/Concentration. Overall, LTLE patients self-reported more cognitive difficulties across all domains. Language was the only domain to emerge as a robust indicator of seizure lateralization (LTLE patients reporting more problems). Neuropsychological test performance did not emerge as a significant predictor for any domain, whereas measures of psychosocial and emotional functioning accounted for a significant but modest amount of variance in all of them. The results suggest caution in using such self-report measures as an ecological extension of objective testing, but suggest a role in assessing self-appraisal of deficits.

Adolescent↗

PubMed2004

Taking charge of epilepsy: the development of a structured psychoeducational group intervention for adolescents with epilepsy and their parents.

Children and adolescents with epilepsy frequently experience poor psychosocial outcomes due to numerous factors such as perceived stigma, behavior problems, academic difficulties, and depression. Health psychology research has documented the effectiveness of psychoeducational interventions aimed at improving psychosocial outcomes for individuals with a variety of health conditions. With increasing numbers of adolescents living with epilepsy, interest in improving the quality of life for this particular population has grown. There remains, however, a paucity of research concerning psychosocial interventions for adolescents with epilepsy. The present study outlines the development and initial implementation of a 6-week structured psychoeducational group intervention for adolescents with epilepsy and their parents. Preintervention, the QOLIE-AD-48, Childhood Depression Inventory, and Revised Children's Manifest Anxiety Scale were administered. Educational topics included medical aspects of epilepsy, healthy lifestyle behaviors, family and peer relationships, understanding self-image and self-esteem, and stress management techniques. Participants were introduced to a variety of cognitive-behavioral strategies, and were encouraged to share their own experiences with epilepsy. Feedback from adolescent and parent participants indicated that the intervention was relevant to their needs, helped them better understand their epilepsy, and allowed an opportunity for positive peer support. Also, postintervention outcome measurement indicated an overall positive trend for quality of life improvement in the adolescents.

Adaptation, Psychological↗

PubMed2004

Confirmatory factor analysis of the california verbal learning test in patients with epilepsy: relationship to clinical and neuropathological markers of temporal lobe epilepsy.

Latent constructs involved in California Verbal Learning Test (D. C. Delis, J. H. Kramer, E. Kaplan, & B. A. Ober, 1987) performance were examined using confirmatory factor analysis in 388 epilepsy surgery candidates. Eight factor models were compared. A single-factor model was examined, along with 7 models accommodating constructs of auditory attention, inaccurate recall, and delayed recall in different combinations. The retained model consisted of 3 correlated factors: Auditory Attention. Verbal Learning, and Inaccurate Recall. Validity of this factor structure was examined in a subsample of patients with left and right temporal lobe epilepsy. All 3 factors were related to seizure focus and magnetic resonance imaging hippocampal volume. Only Verbal Learning was related to hippocampal neuropathology, supporting the distinction between learning and attention in the factor structure.

Adolescent↗

PubMed2003

Loss of calculation abilities in patients with mild and moderate Alzheimer disease.

BACKGROUND: Calculation deficits are a common early manifestation of Alzheimer disease (AD). OBJECTIVE: To investigate oral and written calculation skills in AD patients using quantitative and qualitative methods. DESIGN: Comparison among controls, patients with mild AD, and patients with moderate AD on measures of arithmetic skill. SETTING: Tertiary care university medical center. PARTICIPANTS: Twenty patients with AD (11 with mild AD, 9 with moderate AD) and 23 elderly controls. MAIN OUTCOME MEASURES: Tests of oral arithmetic (Wechsler Adult Intelligence Scale-Third Edition [WAIS-III] Arithmetic subtest) and written arithmetic (Wide Range Achievement Test-3 [WRAT-3] Arithmetic subtest) were administered, and overall group differences were examined. Errors on selected WRAT-3 problems were qualitatively analyzed across groups using a set of error codes. RESULTS: Patients with mild and moderate AD performed significantly below controls on both oral and written arithmetic tasks (P<.001). Patients with moderate AD performed worse than those with mild AD on written arithmetic (P<.002) but not on oral arithmetic tasks. On selected WRAT-3 problems, single- and multiple-digit addition and subtraction operations and single-digit division operations were preserved in patients with mild AD. In contrast, only single-digit addition was preserved in patients with moderate AD. Errors of operation substitution and number position were the most common error types observed in AD patients. Patients with moderate AD displayed multiple error types and high incidence rates compared with controls, while patients with mild AD exhibited error types and incidence rates intermediate to controls and patients with moderate AD. CONCLUSIONS: A decline in calculation abilities is one of the hallmark cognitive features of AD. Patients with mild AD maintain relative preservation of simple written calculation skills but demonstrate marked impairment as task complexity increases. Patients with moderate AD demonstrate global impairments extending to the simplest arithmetic skills. These findings suggest that loss of calculation abilities in AD is both hierarchical (by arithmetic operation) and a function of disease severity.

Aged↗

PubMed2003

Temporal lobectomy in congenital porencephaly associated with hippocampal sclerosis.

BACKGROUND: Clinical and neuroimaging features of patients with epilepsy and coexisting extratemporal porencephaly and hippocampal sclerosis have been previously described. OBJECTIVE: To present the clinical characteristics and surgical outcome of 6 patients with intractable epilepsy and coexisting extratemporal porencephaly and hippocampal sclerosis. PATIENTS AND METHODS: Twenty-four patients with porencephaly and epilepsy were studied. Of these, 6 had an epileptogenic focus in the temporal region. All patients underwent video electroencephalogram monitoring, magnetic resonance imaging studies, and neuropsychological evaluation. Of the subset of patients with temporal lobe epilepsy, 1 patient underwent intracranial electroencephalogram monitoring. Temporal lobe resection was performed in 5 patients. Outcomes were evaluated using the Engel classification. RESULTS: Freedom from seizures was achieved in all patients. Pathologic analysis of the resected tissue confirmed the presurgical diagnosis of mesial temporal sclerosis. CONCLUSION: Patients with extratemporal porencephaly and intractable seizures should be evaluated early and be considered for temporal lobectomy if clinical, magnetic resonance imaging, and electroencephalogram findings support the diagnosis of temporal lobe onset seizures.

Adolescent↗

PubMed2003

Evolving antiepileptic drug treatment in juvenile myoclonic epilepsy.

BACKGROUND: In the face of availability of newer antiepileptic drugs (AEDs) such as lamotrigine and topiramate, there is need to reassess the role of older AEDs in the treatment of juvenile myoclonic epilepsy (JME). OBJECTIVES: To explore whether lamotrigine and topiramate monotherapy or polytherapy can be effective options in the treatment of JME, and to determine whether older AEDs, such as phenytoin and carbamazepine, have a role in the treatment of JME. DESIGN: A retrospective cohort study. SETTING: A large academic teaching hospital. PATIENTS: Seventy-two consecutive JME patients treated with valproic acid, lamotrigine, topiramate, phenytoin, or carbamazepine between April 1, 1991, and March 31, 2001. METHODS: We compared the efficacy of valproic acid, lamotrigine, and topiramate monotherapy or polytherapy in the control of different seizure types of JME, and compared their efficacy and tolerability with the efficacy and tolerability of phenytoin and carbamazepine. RESULTS: Seizure outcome did not differ when patients receiving valproic acid monotherapy (n = 36) were compared with those receiving lamotrigine monotherapy (n = 14), and when patients receiving valproic acid polytherapy (n = 22) were compared with those receiving lamotrigine polytherapy (n = 21) or topiramate polytherapy (n = 15) (P>.05 for all). The combined data of myoclonic seizure control by all 3 AEDs were poorer when compared with the combined data of generalized tonic-clonic seizure control by all 3 AEDs (P =.03), but not when compared with the combined data of absence seizure control by all 3 AEDs (P =.43). Valproic acid, lamotrigine, and topiramate, when compared with phenytoin or carbamazepine, demonstrated significantly better control of myoclonic seizures (P<.01 for all), but not of generalized tonic-clonic seizures (P>.11 for all). CONCLUSIONS: Lamotrigine and topiramate are effective alternative options to valproic acid in the treatment of JME. Lamotrigine is an effective option as monotherapy and polytherapy. Topiramate is an effective option as polytherapy, but more data are needed to determine if it is an effective option as monotherapy. More effective therapy is needed to improve myoclonic seizure control. Older AEDs, such as phenytoin and carbamazepine, may not be indicated in JME patients.

Adult↗

PubMed2003

Confirmatory factor analysis of the WMS-III in patients with temporal lobe epilepsy.

Five competing models specifying the factor structure underlying the Wechsler Memory Scale-Third Edition (D. Wechsler, 1997b) primary subtest scores were evaluated in a sample of patients with intractable temporal lobe epilepsy (N = 254). Models specifying separate immediate and delayed constructs resulted in inadmissible parameter estimates and model specification error. There were negligible goodness-of-fit differences between a 3-factor model of working memory, auditory memory, and visual memory and a nested--more parsimonious--2-factor model of working memory and general memory. The results suggest that specifying a separate visual memory factor provides little advantage for this sample--an unexpected finding in a population with lateralized dysfunction, for which one might have predicted separate auditory and visual memory dimensions.

Adult↗

PubMed2002

In vivo hippocampal metabolic dysfunction in human temporal lobe epilepsy.

BACKGROUND: The nature of functional metabolic disturbances in mesial temporal lobe epilepsy remains unclear. OBJECTIVES: To compare in vivo measures of hippocampal metabolic abnormalities in mesial temporal lobe epilepsy, as acquired with fludeoxyglucose F 18 positron emission tomography and proton magnetic resonance spectroscopic imaging, and to determine the relationship between N-acetylaspartate (NAA) disturbances and well-established derangements of glucose metabolism. DESIGN: Measures of hippocampal glucose metabolism from fludeoxyglucose F 18 positron emission tomography were normalized to whole brain counts to provide a glucose uptake metabolic index. Proton magnetic resonance spectroscopic imaging was performed at 4.1 T, and measures of creatinine/NAA ratio were made from mostly hippocampal-only voxels. Direct comparisons and correlation analysis of measures were performed. SETTING: Presurgical evaluations for treatment of intractable epilepsy. PATIENTS: Twenty-nine patients between July 1994 and June 1996 who were candidates for anterior-medial temporal lobectomy at the epilepsy centers of the University of Alabama at Birmingham and Vanderbilt University schools of medicine were studied. RESULTS: The mean ipsilateral hippocampal glucose metabolic index (0.85) was normal, while the contralateral metabolic index (0.95) was nearly significant for an abnormally elevated measure. The mean ipsilateral hippocampal creatinine/NAA (1.26) was abnormally elevated; the mean contralateral creatinine/NAA (0.88) was normal. Hippocampal glucose and creatinine/NAA measures did not correlate; asymmetry measures also did not correlate. CONCLUSIONS: Hippocampal metabolic disturbances in mesial temporal lobe epilepsy as measured by fludeoxyglucose F 18 positron emission tomography vs proton magnetic resonance spectroscopic imaging reflect different mechanisms of biochemical dysfunction. This lack of correlation is hypothesized to reflect a differential effect of varying degrees of disturbed cellular energy metabolism on mechanisms of glucose use and biosynthesis of NAA.

Adolescent↗

PubMed2002

Risk to verbal memory following anterior temporal lobectomy in patients with severe left-sided hippocampal sclerosis.

BACKGROUND: Previous investigations indicate low risk for memory loss following anterior temporal lobectomy (ATL) in patients with severe hippocampal sclerosis (HS) compared with patients with mild HS. However, these conclusions have been established primarily with group-level analyses. OBJECTIVE: To investigate individual base rate risk for verbal memory loss following ATL in patients who have pathologically verified mild, moderate, or severe HS. PATIENTS AND METHODS: One hundred fifteen patients with unilateral temporal lobe epilepsy (68 with left-sided and 47 with right-sided epilepsy) were included. Acquisition, retrieval, and recognition components of verbal memory, as measured by the California Verbal Learning Test, were assessed before and after ATL. Postoperatively, the degree of neuronal loss and reactive gliosis of the hippocampus was assessed via a 3-tiered rating system establishing mild, moderate, and severe pathologic features. Patients with preoperative magnetic resonance imaging-based evidence of lesions outside the mesial temporal area (side of surgical resection) were excluded. RESULTS: Neither seizure laterality nor severity of HS was associated with preoperative verbal memory performance. Postoperatively, the left-sided ATL group demonstrated significant decline across the acquisition (P<.01), retrival (P<.001), and recognition (P<.001) verbal memory components compared with the right-sided ATL group. Patients who underwent left-sided ATL and had mild HS displayed the largest magnitude and percentage proportion of postoperative decline across all verbal memory components. However, 28 (48%) of the 58 patients who underwent left-sided ATL and who had moderate and severe HS displayed statistically reliable declines on retrieval aspects of verbal memory. Most patients undergoing right-sided ATL, regardless of the extent of hippocampal pathologic features, displayed no postoperative memory change. CONCLUSIONS: Substantial individual heterogeneity of memory outcome exists across groups of patients undergoing ATL, with various degrees of pathologically verified HS. Patients undergoing left-sided ATL who have mild HS seem at greatest risk for broad-spectrum verbal memory decline. However, when examining outcome on a patient-by-patient basis, many patients undergoing left-sided ATL who have moderate to severe HS were also vulnerable to verbal memory loss. This risk seems selective to a retrieval-based aspect of verbal memory.

Adolescent↗