Declarative memory following anterior temporal lobectomy in humans.

Hypothesized that verbal memory decline following anterior temporal lobectomy (ATL) is associated with a lack of significant neuropathology in resected left, but not right, hippocampus and is limited to measures of episodic memory only. Tests of immediate (digit span), semantic (visual naming), and episodic memory as measured by the California Verbal Learning Test (CVLT) were administered before and 6 mo after resection of the anterior left (n?=?36) or right (n?=?26) temporal lobe. There were no effects of hippocampal pathology on measures of immediate or semantic memory for either ATL group or for episodic memory for the right ATL group. Left ATL patients who demonstrated no/mild hippocampal sclerosis exhibited significantly greater postoperative decline in episodic memory compared with those with moderate/marked hippocampal sclerosis on multiple CVLT indices (recall measures, learning characteristics, and contrast measures). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuropsychological outcome following anterior temporal lobectomy in patients with and without the syndrome of mesial temporal lobe epilepsy.

The nature, pattern, and degree of neuropsychological change following anterior temporal lobectomy (ATL) were examined as a function of the presence or absence of the syndrome of mesial temporal lobe epilepsy (MTLE). Fifty-four patients exhibited the syndrome of MTLE, while 34 patients were without the syndrome (non-MTLE). The test-retest performance of a group of 40 epilepsy patients who did not undergo surgery was used to derive regression based estimates of test-retest change. Overall, the MTLE group did not show significant cognitive decline following ATL. In contrast, the left non-MTLE group showed significant declines on verbal memory, confrontation naming, and verbal conceptual ability. Further, verbal memory was the most substantial area of decline, and was independent of seizure outcome. Clinical and theoretical implications of these findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Factors associated with work outcome after anterior temporal lobectomy for intractable epilepsy

PURPOSE: Whereas the effect of anterior temporal lobectomy on seizure frequency is well recognized, less is known about its impact on work status. METHODS: One hundred thirty-four of 190 consecutive patients with temporal lobectomy participated in this study. Eligibility criteria were developed to ensure that only patients with the potential of achieving specific outcomes were included in the corresponding analyses. RESULTS: After surgery, significantly more patients were independent in activities of daily living (p < 0.001) or able to drive (p < 0.001). Income from work also increased (p < 0.01). Nearly one fifth of the patients who were eligible for analysis had either a gain (8%) or a loss (11%) of full- or of part-time work. Univariate analyses revealed the following factors to be associated with full-time work after surgery: student or full-time work within a year before surgery, full-time work experience before surgery, full- or part-time employment experience before surgery, no disability benefits before surgery, low postsurgical seizure frequency, improved postsurgical seizure control, excellent postsurgical seizure control, driving after surgery, and further education after surgery (p < 0.05). Significant factors on multivariate analysis were being a student or having full-time work within a year before surgery [odds ratio, 16.2 (95% CI, 4.3-60.5)], driving after surgery [15.2 (3.2-72.0)], and obtaining further education after surgery [9.2 (2.2-53.0)]. CONCLUSIONS: Anterior temporal lobectomy for intractable epilepsy improves activities of daily living and the ability to drive. Work outcome of this surgery is influenced by presurgical work experience, successful postsurgical seizure control especially to allow driving, and obtaining further education after surgery.     

Role of the hippocampus in sex differences in verbal memory: Memory outcome following left anterior temporal lobectomy.

The authors examined the neural and cognitive bases for sex differences in verbal memory in 57 patients who underwent left anterior temporal lobectomy (ATL) for the treatment of intractable seizures. On the California Verbal Learning Test (D. C. Delis, J. H. Kramer, E. Kaplan, & B. A. Ober, 1987), women recalled more words than men both before and after surgery, regardless of the extent of hippocampal damage. Extent of hippocampal sclerosis was related to memory loss in both men and women. Women's superiority in verbal memory appears to result in part from their use of an efficient encoding strategy. Women were more likely than men to use semantic clustering both before and after ATL, and sex differences in word recall were attenuated after scores were adjusted for semantic clustering. There was no effect of ATL on semantic clustering. Taken together, these results suggest that sex differences in verbal memory are not due to differences in the integrity of the left hippocampus. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Antiepileptic drug treatment following temporal lobectomy

Antiepileptic drug use was documented before and after temporal lobectomy. Carbamazepine, phenytoin, and clobazam were the most commonly used drugs, both pre- and postoperatively. Preoperatively, polytherapy was used in 78% of patients; at 6 months follow-up, 47%; at 12 months, 18%; and at 24 months, 14%. Preoperatively, monotherapy was used in 20% of patients; at 6 months follow-up, 49%; at 12 months, 55%; and at 24 months, 42%. No medication was used preoperatively by 2% of patients; at 6 months follow-up, 2%; at 12 months, 27%; and at 24 months, 44% (p < 0.001). After 2 years, 53% of patients who were seizure free had stopped taking medication, as had 33% who had some seizures after surgery.     

Visual confrontation naming following left anterior temporal lobectomy: A comparison of surgical approaches.

Change in visual confrontation naming was examined following left (speech dominant) anterior temporal lobectomy (ATL) as a function of surgical technique and patient characteristics. Two hundred seventeen patients with intractable left temporal lobe epilepsy were selected according to standard criteria across 8 centers, and combined into 4 surgical approaches to ATL: (a) tailored resections with intraoperative mapping of eloquent cortex, (b) tailored resections with extraoperative mapping, (c) standard resections with sparing of superior temporal gyrus, and (d) standard resections including excision of superior temporal gyrus. Changes in visual confrontation naming were examined with an index of reliable change derived from an independent sample of 90 nonsurgical patients with complex partial seizures. Results showed significant decline in visual confrontation naming following left ATL, regardless of surgical technique. Across surgical approaches, the risk for decline in visual confrontation naming was associated with a later age of seizure onset and more extensive resection of lateral temporal neocortex. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preserved musical abilities following right temporal lobectomy

It has been widely accepted that the right temporal lobe plays a major role in the processing of music. One of the main lines of evidence was derived from Milner's study, published in 1962, which reported that right temporal lobectomy led to a decline in patient scores on four of the six subtests (Tonal Memory, Timbre, Loudness, and Time subtests) of the Seashore Measures of Musical Talents. That finding had led some surgeons and patients to hesitate in choosing right temporal lobectomy as a treatment for intractable epilepsy. The authors examined performance on the Seashore Measures before and after operations in 20 patients with right temporal lobectomy and nine patients with left temporal lobectomy. No disturbances in the Seashore Measures were detected after temporal lobectomy on either side. The extent of these temporal lobectomies was smaller than that of the temporal lobectomies in Milner's study, as measured along the sylvian fissure (1.5-4 cm; mean 2.7 cm, standard deviation (SD) 0.92 cm) and the base of the temporal lobe (3.5-5.5 cm; mean 4.7 cm, SD 0.63 cm). These findings indicate that the region resected on right temporal lobectomy in the present study is not essential for basic musical processing.     

Individual memory change after anterior temporal lobectomy: a base rate analysis using regression-based outcome methodology

PURPOSE: To characterize patterns of base rate change on measures of verbal and visual memory after anterior temporal lobectomy (ATL) using a newly developed regression-based outcome methodology that accounts for effects of practice and regression towards the mean, and to comment on the predictive utility of baseline memory measures on postoperative memory outcome. METHODS: Memory change was operationalized using regression-based change norms in a group of left (n = 53) and right (n = 48) ATL patients. All patients were administered tests of episodic verbal (prose recall, list learning) and visual (figure reproduction) memory, and semantic memory before and after ATL. RESULTS: ATL patients displayed a wide range of memory outcome across verbal and visual memory domains. Significant performance declines were noted for 25-50% of left ATL patients on verbal semantic and episodic memory tasks, while one-third of right ATL patients displayed significant declines in immediate and delayed episodic prose recall. Significant performance improvement was noted in an additional one-third of right ATL patients on delayed prose recall. Base rate change was similar between the two ATL groups across immediate and delayed visual memory. Approximately one-fourth of all patients displayed clinically meaningful losses on the visual memory task following surgery. Robust relationships between preoperative memory measures and nonstandardized change scores were attenuated or reversed using standardized memory outcome techniques. CONCLUSIONS: Our results demonstrated substantial group variability in memory outcome for ATL patients. These results extend previous research by incorporating known effects of practice and regression to the mean when addressing meaningful neuropsychological change following epilepsy surgery. Our findings also suggest that future neuropsychological outcome studies should take steps towards controlling for regression-to-the-mean before drawing predictive conclusions.     

Investigation of executive function change following anterior temporal lobectomy: Selective normalization of verbal fluency.

The nociferous cortex hypothesis predicts that electrophysiological normalization to distal extratemporal brain regions following anterior temporal lobectomy (ATL) will result in improvements in executive functioning. The present study examined the effects of seizure laterality and seizure control on executive function change. The authors administered the Wisconsin Card Sorting Test (WCST), Trails B, and the Controlled Oral Word Association Test to 174 temporal lobe epilepsy patients who underwent ATL. No significant changes were found on the WCST or Trails B tests, regardless of surgery side or seizure-free status. However, verbal fluency significantly improved in seizure-free patients. Findings were consistent with the nociferous cortex hypothesis suggesting selective executive function improvement following ATL. These findings are discussed in terms of recent research demonstrating extrahippocampal metabolic normalization following surgery. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory for emotional words following unilateral temporal lobectomy

We recently reported that patients who had received unilateral temporal lobectomy, including the amygdala and hippocampus, show impaired acquisition in a fear conditioning task (LaBar, LeDoux, Spencer, & Phelps, 1995), indicating a deficit in emotional memory. In the present paper, we examined performance of these patients on two verbal, emotional memory tasks in an effort to determine the extent of this deficit. In Experiment 1, subjects were asked to recall emotional and non-emotional words. In Experiment 2, subjects were asked to recall neutral words which were embedded in emotional and non-emotional sentence contexts. Both temporal lobectomy subjects and normal controls showed enhanced recall for emotional words (Experiment 1) and enhanced recall for neutral words embedded in emotional sentence contexts (Experiment 2). These results suggest that the deficit seen in emotional memory following unilateral temporal lobectomy is not a global deficit and may be limited to specific circumstances where emotion influences memory performance. Several hypotheses concerning the discrepancy between the present studies and the fear conditioning results (LaBar et al., 1995) are discussed.     

Differences between nouns and verbs after anterior temporal lobectomy.

To test the claim that lesions of left anterior and middle temporal cortical structures specifically impair processing of nouns but not verbs, 56 left-hemisphere-language-dominant patients who had undergone anterior temporal lobectomy (ATL) completed tasks assessing confrontation naming of pictured objects and actions, generation of synonyms for nouns and verbs, and semantic lexical judgments about nouns and verbs. Compared with right ATL patients left ATL patients were impaired across different tasks that assessed naming and comprehension of high-imageability as well as low-imageability nouns. These groups did not differ, however, in verb naming or comprehension on most tasks. Results are consistent with the hypothesized specialization of left temporal lobe structures for processing nouns and suggest that naming problems commonly seen after left ATL extend beyond difficulties with retrieving object names and may be related to subtle disturbances in comprehension of the meanings underlying nominal word forms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Deficits in complex visual perception following unilateral temporal lobectomy

Although human temporal cortex is known to be important for short- and long-term memory, its role in visual perception is not well understood. In this study, we compared the performance of three patients with unilateral temporal lobectomies to that of normal controls on both "simple" and "complex" visual discriminations that did not involve explicit memory components. Two types of complex tasks were tested that involved discriminations secondary to texture segmentation. These were contrasted with simple discriminations using luminance-defined stimuli. Patients showed impaired thresholds only on tasks involving texture segmentation, performing as well as controls when the targets were defined by luminance rather than texture. The minimum stimulus presentation times for threshold performance were also measured for all tasks and found to be elevated in temporal lobectomy patients relative to controls. Although the magnitude of the deficits observed was substantial, loss was equivalent in ipsi- and contra-lesional regions of the visual field. Additional control experiments showed that the patients' perceptual deficits were not due, even in part, to disturbances of basic visual capacities such as acuity and contrast sensitivity. Our results indicate that temporal lobe damage disrupts complex, but not simple, visual discriminations throughout the visual field.     

Management of TMD caused by temporal head trauma

This report followed the management of a 56-year-old female suffering from TMD caused by trauma to her temporal head area. The management consisted of occlusal devices until her condition stabilized followed by prosthodontic rehabilitation to obtain and maintain a physiologic maximum intercuspation.     

Visual and quantitative ictal EEG predictors of outcome after temporal lobectomy

PURPOSE: We investigated whether visual and quantitative ictal EEG analysis could predict surgical outcome after anteromesial temporal lobectomy (AMTL) in which mesial structures, basal, and temporal tip cortex were resected. METHODS: We retrospectively reviewed 282 presurgical scalp-recorded ictal EEGs (21- to 27-channel) from 75 patients who underwent AMTL. We examined the pattern of seizure onset (frequency, distribution, and evolution) and estimated the principal underlying cerebral generators by using a multiple fixed dipole model that decomposes temporal lobe activity into four sublobar sources (Focus 1.1). We correlated findings with a 2-year postoperative outcome. RESULTS: Sixteen patients had seizures with a well-lateralized, regular 5 to 9-Hz rhythm at onset, that most often had a temporal or subtemporal distribution. All patients became seizure free after surgery. In 51 patients, seizure onset was remarkable for lateralized slow rhythms (<5 Hz), which sometimes appeared as periodic discharges, were often irregular and stable only for short periods (<5 s), and had a widespread lateral temporal distribution. Among these a favorable surgical outcome was encountered in patients with seizures having prominent anterior-tip sources ( 16 of 17 seizure free), whereas those with dominant lateral or oblique sources had a less favorable outcome (three of 14 and 13 of 18, respectively). Irregular, nonlateralized slowing characterized seizure onsets in eight patients. Three patients became seizure free after surgery. CONCLUSIONS: Both visual and quantitative sublobar source analysis of scalp ictal EEG can predict surgical outcome in most cases after AMTL and complement non-invasive presurgical evaluation.     

Emotion recognition from faces and prosody following temporal lobectomy.

The anteromedial temporal lobe has been found to participate in processing emotion, but there are unresolved discrepancies in the literature. To address this issue, the authors investigated recognition of emotion from faces and from prosody in 26 participants with unilateral temporal lobectomy (15 left, 11 right) and in 50 brain-damaged controls. Participants with right, but not left, temporal lobectomy did significantly worse in recognizing fear from facial expressions. There were no group differences in recognizing emotional prosody. Neither IQ nor basic perceptual function accounted for task performance; however, there was a moderate negative correlation between extent of amygdala damage and overall performance. Consistent with some prior studies, these findings support a role for the right anteromedial temporal lobe (including amygdala) in recognizing emotion from faces but caution in drawing conclusions from small group samples. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Predictors of outcome following severe head trauma: follow-up data from the Traumatic Coma Data Bank

Outcome as a function of employment status or return to school was evaluated in severely head-injured patients. A priori we selected the most salient demographic, physiological, neuropsychological and psychosocial outcome predictors with the aim of identifying which of there variables captured at baseline or 6 months would best predict employability at 6 or 12 months. Based on the patients evaluated at 6 months, 18% of former workers had returned to gainful employment and 62% of former students had returned to school. For those not back to work or school at 6 months, 31% of the former workers and 66% of the former students had returned by 12 months. Age, length of coma, speed for both attending and motor movements, spatial integration, and intact vocabulary were all significantly related to returning to work or school. The three most potent predictors for returning to work or school were intactness of the patient's verbal intellectual power, speed of information processing and age.     

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.     

Psychiatric outcome of temporal lobectomy for epilepsy: incidence and treatment of psychiatric complications

PURPOSE: To determine the incidence of psychiatric disorders before and after surgical treatment for partial epilepsy and to document the effectiveness of their treatment. METHODS: Fifty consecutive patients treated surgically for focal epilepsy (44 temporal and six frontal) were evaluated by established neuropsychiatric methods before surgery and over a mean period of 2 years after surgery. The patients with interictal dysphoric disorders, with or without psychotic episodes, were treated with tricyclic antidepressant medication alone or combined with serotonin selective reuptake inhibitors and, if necessary, with the addition of risperidone. RESULTS: Before surgery, 25 (57%) of the 44 patients with temporal lobe epilepsy had dysphoric disorders. After surgery, 17 (39%) of the 44 patients experienced either de novo psychiatric complications (six psychotic episodes, six dysphoric disorders, and two depressive episodes) or exacerbation of preoperative dysphoric disorder (three patients). Eight previously intact patients of the 19 (42%) developed dysphoric disorders after surgery that were significantly related to recurrence of seizures. All psychiatric complications occurred in the first 2 months after surgery, except for the six patients intact before surgery, who had a recurrence of seizures. A significant predictor of ultimate excellent psychiatric outcome was complete absence of seizures after surgery. All postoperative psychiatric complications remitted on treatment with psychotropic medication in the compliant patients. CONCLUSIONS: An exceptional psychiatric morbidity is associated with the months after temporal lobectomy. Possible pathogenetic mechanisms are discussed. Antidepressant drugs are very effective in treating the psychiatric disorders of chronic epilepsy; their use in conjunction with the surgical treatment of epilepsy appears to be crucial for the overall positive outcome of a significant number of patients.     

Posttraumatic hypopituitarism: anterior pituitary insufficiency secondary to head trauma

A 30-year-old woman, who was involved in an automobile accident two years before admission, presented with hypopituitarism. Deficits of ACTH, FSH, LH, GH, and borderline TSH were demonstrated. Normal TRF response and elevated prolactin levels indicated residual normal anterior pituitary tissue with inadequate hypothalamic control. We have briefly reviewed the subject of posttraumatic hypopituitarism.