Biomedical subjects

B P Hermann

Publications and source records attributed to B P Hermann.

At least 37 records · Page 2Linked to original sources

PubMed1999

Determinants of confrontation naming performance.

Confrontation naming tests are commonly employed in neuropsychological assessment. Surprisingly little work has been done, however, to determine how various demographic, linguistic, and disease status variables influence patterns of performance on these tests. The present study examined data on the Boston Naming Test (BNT) from a total of 1,131 subjects, including 719 normals, 325 patients with Alzheimer's disease, and 87 patients with temporal lobe epilepsy. The effects of age, education, gender, and diagnostic group were examined with respect to overall scores, the influence of phonemic cuing, and performance on individual items. Profiles of scores on individual items were similar across diagnostic groups, suggesting that anomia is characterized by quantitative rather than qualitative changes in naming performance. Age and education systematically influenced scores. There was a significant effect of gender across diagnostic groups (males scoring higher than females), which appears to be due to performance on specific items. Phonemic cuing effects were similar across groups. The results are discussed with respect to the neuropsychological construct of confrontation naming and the clinical interpretation of performance on the BNT.

Journal Article↗

PubMed1998

Synaptophysin immunohistochemistry densitometry measurement in resected human hippocampus: implication for the etiology of hippocampal sclerosis.

Synaptophysin (SY) is a protein expressed at presynaptic vesicles. SY immunohistochemistry (IHC) was undertaken in surgically resected hippocampal specimens from 25 patients with intractable epilepsy. All were investigated with chronic ictal EEG videotelemetry, which showed a temporal onset in each case, and all had normal magnetic resonance imaging (MRI). The density of reaction product of SY IHC was used to generate optical density (OD) measurements as an estimate of synaptic density in CA1 and CA4 fields (ODCA1 and ODCA4), and inner third and outer two-thirds of the molecular layer of the dentate gyrus (ODIML and ODOML). There was significant correlation between ODCA1 (r=0.619, P=0.001) and ODCA4 (r=0.639, P=0.001) and onset age of epilepsy. There was no correlation between ODCA1 and duration of epilepsy. There was correlation between ODCA4 and duration (r=-0.412, P=0.041), but partial correlations showed no significant correlation between ODCA4 and duration when controlling for onset, although correlation between ODCA4 and onset when controlling for duration remained significant (r=0.536, P < 0.01). Univariate ANOVA revealed onset age to be the only predictor of ODCA1 and ODCA4. Chronological age and duration were not predictors. There was no correlation between ODIML or ODOML and either onset age or duration. ODIML and ODOML were not predicted by onset age, duration or chronological age. These findings support the hypothesis that the major cause of hippocampal sclerosis is an age specific insult rather than the result of repeated seizures.

Adult↗

PubMed1998

Does presurgical IQ predict seizure outcome after temporal lobectomy? Evidence from the Bozeman Epilepsy Consortium.

PURPOSE: Considerable debate exists concerning whether the presence of low preoperative IQ should be a contraindication for focal resective epilepsy surgery. METHODS: We examined the relationship between baseline IQ scores and seizure outcome in 1,034 temporal lobectomy cases from eight epilepsy surgery centers participating in the Bozeman Epilepsy Consortium. RESULTS: Those patients who continued to have seizures following surgery had statistically lower preoperative IQ scores than those who were seizure-free (p < 0.009), but only by 2.3 points. This small but statistically significant relationship was fairly robust; it was observed across seven of the eight centers, and indicates that the findings can be generalized. Among patients with IQ scores of < or = 75, 32.8% continued to have seizures following surgery, whereas 23.8% and 16.9% were not seizure-free when IQ scores were between 76 and 109 and > or = 110, respectively. Relative risk analyses revealed no significant increase in risk among patients with low IQ scores who had no structural lesions other than mesial temporal sclerosis. However, patients with IQ scores of < or = 75 had nearly a fourfold (390%) increase in risk for continued seizures as compared with those with higher IQ scores if structural lesions were present. CONCLUSIONS: While our results suggest that preoperative IQ scores alone are not good predictors of seizure outcome and should not be used to exclude patients as potential surgical candidates. IQ scores can be useful for counseling patients and their families concerning the relative risks of surgery.

Comorbidity↗

PubMed1998

Naming decline after left anterior temporal lobectomy correlates with pathological status of resected hippocampus.

PURPOSE: To evaluate the determinants of postoperative change in visual confrontation naming ability and the differential sensitivity of two common tests of confrontation naming. METHODS: In a group of 99 patients undergoing lobectomy of the left, language-dominant anterior temporal lobe, we examined naming ability using two measures: the 60 item Boston Naming Test (BNT), and the Visual Naming (VN) subtest of the Multilingual Aphasia Examination (MAE). ATL entailed resection of lateral temporal lobe followed by microsurgical complete removal of hippocampus. Language mapping was not performed. The status of the resected hippocampus was graded on a scale 0-4 of hippocampal sclerosis (HS). A dichotomous grouping HS- (grades 0 and 1, n = 34) and HS+ (grades 3 and 4, n = 61) was effected. Age at surgery, age of epilepsy onset, sex, extent of lateral temporal resection, Full-Scale IQ (FSIQ), and preoperative naming scores were also examined as potential predictors of pre- versus postoperative naming change. RESULTS: Preoperative BNT and VN scores were significantly worse for HS+ than for HS- (BNT, p < 0.05; VN, p = 0.001). Postoperatively, BNT and VN scores significantly declined for HS- as compared with HS+ patients (p < 0.001). For individual risk, the 90th centile of reliable change index (RCI) was used. By this criterion, of the total sample, 39% evidenced decline on the BNT and 17% evidenced decline on the VN. Logistic regression analysis with backward elimination showed HS to be the only predictor of decline in BNT and HS and sex to be the only predictors of VN decline. Males were more at risk than females. Age, age at onset, extent of lateral resection, preoperative scores, and FSIQ were not predictors. Using age at onset as a proxy for HS+/HS- we calculated probabilities for naming decline for given onset age. CONCLUSIONS: Both preoperative and postoperative change in naming ability are associated with the pathological status of the hippocampus. The potential interpretations and implications of these findings are discussed.

Adult↗

PubMed1998

Symptoms of depression and anxiety in pediatric epilepsy patients.

PURPOSE: We assessed rates of symptoms of anxiety and depression among pediatric patients with epilepsy. METHODS: We administered the Revised Child Manifest Anxiety Scale (RCMAS), and Child Depression Inventory (CDI) to 44 epilepsy patients aged 7-18 years (mean age 12.4 years). Demographic, socioeconomic, and epilepsy-related information was examined in relation to depression and anxiety scores. RESULTS: No patients had been previously identified to have depression or anxiety. However, 26% had significantly increased depression scores and 16% met criteria for significant anxiety symptomatology. CONCLUSIONS: Symptoms of depression and anxiety are common among pediatric patients with epilepsy and appear to be overlooked by care providers.

Adolescent↗

PubMed1997

Neuropsychological characteristics of the syndrome of mesial temporal lobe epilepsy.

OBJECTIVE: To identify the neuropsychological features of the syndrome of mesial temporal lobe epilepsy (MTLE), a surgically remediable epileptic syndrome defined by the presence of hippocampal sclerosis, using a broad and comprehensive neuropsychological test battery. SETTING: Epilepsy surgery center. PATIENTS: After scalp adn invasive electroencephalographic monitoring, a consecutive series of 107 adults were found to have intractable complex partial seizures of unilateral left (n = 62) or right (n = 45) temporal lobe origin. Patients were included if they were not retarded and had left hemisphere dominance for speech but no magnetic resonance imaging abnormalities other than hipocampal sclerosis. Histopathological analyses of resected hippocamppi showed that 66 patients had hippocampal sclerosis (MTLE+), and 41 did not have evidence of significant hippocampal sclerosis (MTLE-). INTERVENTIONS: None. MAIN DEPENDENT MEASURES: A comprehensive battery of neuropsychological tests that included measures of intelligence, academic achievement, language, visuoperceptual or visuospatial function, memory and learning, attention, and problem-solving abilities. RESULTS: The syndrome of MTLE was associated with considerable generalized cognitive impairment (in intelligence, academic achievement, language, and visuospatial functions), but not related to adequacy of performances in other selected cognitive domains (attention or concentration, executive functions). Material-specific memory effects were obtained-primarily for verbal memory in association with left-sided MTLE. CONCLUSIONS: Distinct neuropsychological features of spared, compromised, and laterality-specific cognitive impairments characterize the syndrome of MTLE. This information needs to be incorporated into formal syndrome criteria.

Adult↗

PubMed1997

Reorganization of verbal memory function in early onset left temporal lobe epilepsy.

The purpose of this investigation was to examine the issue of reorganization of verbal memory function following early insult to the left mesial temporal region. It was hypothesized that reorganization of memory function was most likely to occur in those patients with an early age of seizure onset who have a more limited degree of extra-hippocampal neuropathology. Fifty-four patients with epilepsy of unequivocal left temporal lobe origin were classified into four groups on the basis of the presence/absence of hippocampal sclerosis and degree of postoperative seizure relief. Measures of verbal learning and memory as well as nonmemory measures were administered both before and 6 to 8 months after anterior temporal lobectomy. Findings were consistent with the reorganization proposal. The clinical and theoretical significance of the findings are discussed.

Adult↗

PubMed1997

Effect of Wada memory stimulus type in discriminating lateralized temporal lobe impairment.

PURPOSE: To examine the effects of memory stimulus type on Wada memory performance. METHOD: Ninety-six patients (left, 47; right, 49) from four epilepsy centers who were candidates for anterior temporal lobectomy (ATL) and who have subsequently undergone surgery were studied. Patients with atypical cerebral language lateralization or with evidence on magnetic resonance imaging (MRI) to suggest a lesion other than hippocampal sclerosis were excluded. Wada memory performance was obtained by using both real objects and line drawings as memory stimuli. RESULTS: Wada memory laterality scores with either real objects or line drawings as memory stimuli discriminated left from right-ATL groups. However, objects were superior to line drawings in making this differentiation. Further, objects were superior to line drawings in individual patient classification of candidates for left ATL, with no difference in the classification rates using either objects or line drawings in candidates for right ATL. CONCLUSIONS: Type of memory stimuli is an important factor affecting memory results during the Wada test.

Amobarbital↗

PubMed1997

Differential rates of age of seizure onset between sexes and between hemispheres?

In a descriptive analysis of 158 patients with temporal lobe epilepsy, Taylor (1969) reported that the age of first seizure varied systematically as a function of laterality and sex. We conducted inferential analyses of Taylor's original data which (1) provided support for his proposal of disproportionate left hemisphere vulnerability to seizure onset in early life, but (2) failed to provide evidence of sex differences in age of onset of unilateral seizures. Examination of these effects in a larger sample of 844 patients drawn from the Bozeman Epilepsy Consortium provided some additional support for findings from the inferential analysis. Specifically, the left hemisphere appeared more vulnerable to seizure onset in childhood, this increased vulnerability extending to about age 5 years. Age of onset of seizures was not different when males and females were compared. Thus, reanalysis of Taylor's original data as well as examination of data from a larger, more contemporary sample suggest that seizure onset varies as a function of laterality, but not sex.

Adult↗

PubMed1997

The use of figural reproduction tests as measures of nonverbal memory in epilepsy surgery candidates.

The construct of nonverbal memory, as assessed by figural reproduction tests, has recently been questioned by a number of investigators. The purpose of this study was to reexamine this construct and its relationship to right temporal lobe dysfunction. Figural reproduction test scores were examined in 757 epilepsy surgery candidates obtained from 8 epilepsy centers participating in the Bozeman Epilepsy Consortium. All participants exhibited unequivocal evidence of left (LTL) or right (RTL) temporal lobe epilepsy observed in ictal and interictal EEG recordings. All subjects also had IQ scores exceeding 70, right-hand preference, and left hemisphere language dominance confirmed by intracarotid sodium amytal testing. Comparisons of LTL and RTL groups showed no significant differences in scores on the Visual Reproduction subtests from the Wechsler Memory Scale (WMS) or Wechsler Memory Scale-Revised (WMS-R) or on the copy and delayed recall conditions of the Rey-Osterrieth Complex Figure Test (ROCFT). Significant differences were observed among centers on WMS and ROCFT scores, which are likely to be a result of variations in administration and/or scoring procedures. The lack of significant differences between LTL and RTL groups in this large sample raise questions about the nature of nonverbal memory and its relationship to right temporal lobe dysfunction.

Adult↗

PubMed1996

Hippocampal sclerosis and verbal encoding ability following anterior temporal lobectomy.

Previous research has shown that the degree of verbal memory decline following left anterior temporal lobectomy (ATL) is inversely related to the extent of neuronal dropout in resected left hippocampus. The goal of this investigation was to clarify further the nature of the free recall impairment and to determine the relative contribution of verbal retrieval and encoding processes. Seventy-six patients who underwent left (n = 46) or right (n = 30) ATL were classified according to the presence or absence of hippocampal sclerosis and pre- to postoperative changes in free recall, cued recall and recognition memory for verbal material were examined. Surgically induced free recall impairments were selectively associated with resection of nonsclerotic left hippocampus and represented a 29-35% decline in verbal learning ability. These free recall deficits were due to postoperative impairment in verbal encoding efficiency, not retrieval difficulties. Assessment of false positive recognition errors indicated that resection of nonsclerotic left hippocampus selectively impaired the ability to encode stimulus uniqueness within correct semantic fields. The clinical and theoretical significance of these results are discussed.

Adult↗

PubMed1996

Relationship of hippocampal sclerosis to duration and age of onset of epilepsy, and childhood febrile seizures in temporal lobectomy patients.

Controversy exists as to whether hippocampal sclerosis (HS) is a preexisting cause or a consequence of seizures. We investigated 122 consecutive patients who underwent anterior temporal lobectomy for intractable epilepsy between 1989 and 1992. MRI scans were normal apart from evidence of HS in 5 cases. The degree of HS was graded from 0 to 4. There was a significant inverse correlation between age of seizure onset and grade of HS (P < 0.0001), and a positive correlation between duration of epilepsy and grade of HS (P < 0.001). Using a dichotomous grouping of HS (HPSC - for grades 0 and 1 [no/mild HS], and HPSC + for grades 3 and 4 [moderate/marked HS]), there was a positive correlation between HPSC + and a history of childhood febrile seizures (CFS) (P = 0.003), earlier age of onset of epilepsy (P < 0.001) and longer duration of epilepsy (P < 0.001). There was no correlation with history of particularly prolonged individual seizures. Partial correlations after controlling for age at onset of epilepsy showed that there was no longer a significant relationship between HPSC + and duration of epilepsy. After controlling for duration of epilepsy, the relationship between HPSC + and age of onset remained significant (P < 0.001). The correlation between HPSC + and CFS, controlling for age at onset, was not significant. A series of logistic regression analyses showed age at onset to be the only predictor of HPSC +. It is concluded that this is supportive evidence for preexisting HS being a cause of temporal lobe epilepsy and not a consequence of seizures.

Adult↗

PubMed1996

A comparison of health-related quality of life in patients with epilepsy, diabetes and multiple sclerosis.

The purpose of this investigation was to compare self-reported health-related quality of life (HRQOL) in epilepsy compared to another neurological condition or a non-neurological chronic illness. Patients with epilepsy (N = 271), multiple sclerosis (N = 85) and diabetes (N = 555) completed a generic measure of HRQOL (RAND 36-Item Health Survey 1.0 (SF-36)), and the eight SF-36 scale scores were compared across groups, adjusting for differences in sociodemographic characteristics and co-morbid medical conditions. Patients with multiple sclerosis reported significantly worse HRQOL compared to both the epilepsy and diabetes groups (who did not differ from one another) on the Physical Functioning, Role Limitations-Physical, Energy, and Social Function scales. Patients with epilepsy and multiple sclerosis did not differ from one another but reported significantly lower HRQOL scores than the diabetes group on the Emotional Well-Being and Role Limitations-Emotional scales. However, the epilepsy group reported better health perceptions compared to the diabetes and multiple sclerosis patients. Generic measures of HRQOL appear useful in identifying some effects of neurological disease, but disease-targeted supplements may be required to more clearly identify the impact of epilepsy on quality of life.

Adult↗

PubMed1996

The effects of human hippocampal resection on the serial position curve.

The purpose of this study was to examine the contribution of the human hippocampal formation to the classic serial position curve. Seventy-seven patients who underwent anterior temporal lobectomy (ATL) (47 left, 30 right) were administered a list learning task before and after surgery, and changes in the serial position curve were examined. Forty nonsurgical patients with complex partial seizures were tested at comparable intervals and served as controls. Changes in the serial position curve were seen only after left ATL, and almost exclusively among patients without hippocampal sclerosis. Patients without left hippocampal sclerosis, and who therefore underwent resection of hippocampus that was to a considerable degree structurally (and presumably functionally) intact, showed significant declines in recall from the primacy and middle portions of the list compared to all other groups. There was no change in the recency portion of the list. Patients with left hippocampal sclerosis showed only a modest decline in recall from the middle region compared only to the control group, and the right ATL groups did not show any significant changes in serial position recall. These findings demonstrate the contribution of the left hippocampus to those discrete portions of the serial position curve which rely on secondary memory, and have implications for assessing the effects of ATL on memory function.

Adult↗

PubMed1996

Intractable epilepsy due to meningitis: results of surgery and pathological findings.

Between 1986 and 1992, among a total of 668 craniotomies performed for intractable epilepsy, 13 (1.9%) patients had a presumed aetiology of a previous episode of meningitis. Twelve were investigated with chronic electrocorticography with subdural electrodes which showed mesial temporal onset in eight, regional temporal onset in three and bilateral diffuse onset in one. One patient underwent corpus callosotomy and 12 anterior temporal lobectomy (ATL) (6L, 6R). The pathology in the resection cases was hippocampal sclerosis in six and gliosis in six. Mean length of follow up was 3 years (range 1-6 years). Ten of the 12 (83%) ATL patients were seizure free (six off medications). Two ATL patients and the callosotomy patient were significantly improved. It is concluded that in patients where the presumed aetiology of intractable epilepsy is meningitis and widespread damage may therefore be expected, this does not necessarily indicate multifocality, and the prognosis following resective surgery appears to be good.

Adolescent↗

PubMed1996

MRI confirmation of accuracy of freehand placement of mesial temporal lobe depth electrodes in the investigation of intractable epilepsy.

Stereotactic techniques are commonly used to place intracerebral depth electrodes. We placed 15 depth electrodes (9R, 6L) freehand, orthogonally into temporal lobes in 12 patients undergoing monitoring with subdural strip electrodes in the evaluation of their intractable epilepsy. Coronal MRI was performed with the electrodes in place. The mean distance from the closest depth electrode contact to the hippocampus was 0.8 mm (range 0-5 mm). In 11 instances the closest contact was either within or making contact with the hippocampus, and in another three it was within 3 mm. For 13 electrodes, the most distal contact was the closest to the hippocampus, for two the penultimate contact was closest. There were no complications from electrode placement. Ictal onset was mesial temporal in 11 patients and frontal in one. Temporal onset was detectable in the depth electrode in each case, usually simultaneously with the onset in the subdural electrode although often the discharge was better developed in the depth electrode. We conclude that freehand placement of depth electrodes orthogonally into the temporal lobe can achieve a degree of accuracy sufficient to localize seizure onset in the mesial temporal lobe.

Adolescent↗

PubMed1996

Empirical techniques for determining the reliability, magnitude, and pattern of neuropsychological change after epilepsy surgery.

PURPOSE: We assessed test-retest neuropsychological performance in patients with complex partial seizures to derive reliable change indices (RCIs) and regression-based norms for change, indices that may be helpful in assessing cognitive outcome after anterior temporal lobectomy. METHODS: Forty patients with complex partial seizures (CPS) who did not undergo epilepsy surgery were administered a comprehensive neuropsychological battery on two occasions. Their test-retest data were used to compute both RCIs and regression-based norms for change for each neuropsychological index. RCIs corrected for practice effects provide a confidence interval (CI) indicating the degree of performance change required to exceed the variability attributable to sources of error (e.g., practice, test-retest reliability). Regression-based norms for change also correct for several sources of measurement error and examine observed versus expected test-retest changes on a common metric, thereby facilitating determination of the degree and relative magnitude of change across cognitive domains. RESULTS: Mean changes in test-retest performance were generally modest, but were evident across several test measures. Our data indicate a considerable degree of individual variability in test-retest performance. CONCLUSIONS: RCIs and regression-based norms are complementary indexes and can be particularly useful in examining the test-retest performance of individual patients who undergo epilepsy surgery as well as in the more general investigation of cognitive outcome after epilepsy surgery.

Adult↗

PubMed1996

Relation between intracarotid amobarbital memory asymmetry scores and hippocampal sclerosis in patients undergoing anterior temporal lobe resections.

The intracarotid amobarbital procedure (IAP) is used to evaluate memory function preoperatively in candidates for anterior temporal lobe resections (ATL). We examined IAP memory asymmetry scores in 30 patients undergoing ATL (17 R, 13 L), as a function of the presence (HS+) or absence (HS-) of hippocampal sclerosis. Ictal onset zones were determined by extraoperative recording with subdural strip electrodes in all but 3 patients in whom magnetic resonance imaging (MRI) scan showed HS. MRI scans were otherwise normal. All patients were left hemisphere dominant for language except 1, in whom language was represented bilaterally. IAP memory testing involved presentation of eight subjects during anesthesia of each hemisphere, followed by recognition testing after patients recovered from amobarbital effects. A score of 1 was given for each correctly recognized object, and 0.5 was deducted for each false-positive identification. There were 16 foils. A total asymmetry score was calculated, which was positive if there was agreement between the direction of the symmetry and side of operation and negative if reversed. The mean asymmetry score for HS- (n = 8) was 0.9; that for HS+ (n = 22) was 4.1 (p < 0.01). IAP memory performance provided lateralizing information (asymmetry score > or = + or -2) in 73% of cases; among these, the lateralization was correct in 91%. Our data indicate that IAP memory asymmetry predicts both laterality of ictal onset and the presence of HS.

Adolescent↗