Bilaterally symmetric hippocampi and surgical outcome.

This study investigates the relationship between hippocampal volume and seizure control following temporal lobectomy in patients with volumetrically symmetric hippocampi. Forty-six patients who underwent temporal lobectomy for nonlesional temporal-lobe-onset seizures, and in whom the volumes of the two hippocampi were roughly equal (ie, the difference of the right minus the left hippocampal volume fell between -0.1 and 0.3 cm3), were included. We graded postoperative seizure control on a four-point scale according to criteria defined by Engel. We found no relationship between the hippocampal sum (sum of the right plus left hippocampal volumes normalized for cranial size) and operative outcome. A satisfactory operative outcome is possible in patients with bilaterally symmetric mesial temporal sclerosis by MRI criteria.

MRI hippocampal volumes and memory function before and after temporal lobectomy.

We investigated the relationship between preoperative MRI hippocampal volumes and clinical neuropsychological memory test data obtained before and after temporal lobectomy and amygdalohippocampectomy for intractable epilepsy in 44 left (LTL) and 36 right (RTL) temporal lobectomy patients. In LTL patients, the difference (right minus left hippocampal volume) between hippocampal volumes (DHF) was significantly (p < 0.001) correlated (r = 0.61) with postoperative verbal memory change as measured by a delayed memory percent retention score from the Wechsler Memory Scale-Revised, Logical Memory subtest. DHF was also positively associated with postoperative memory for abstract geometric designs in LTL patients (r = 0.49, p < 0.005). Resection of a relatively nonatrophic left hippocampus was associated with poorer verbal and visual memory outcome. In RTL patients, larger right adjusted (for total intracranial volume) hippocampal volume was associated with decline in visual-spatial learning, but not memory, following surgery. MRI hippocampal volume data appear to provide meaningful information in evaluating the risk for memory impairment following temporal lobectomy.

Effects of anomalous language representation on neuropsychological performance in temporal lobe epilepsy.

OBJECTIVE: To examine the effects of anomalous language representation (i.e., mixed- and right-cerebral dominant) on neuropsychological performance. BACKGROUND: Right cerebral language dominance resulting from early cerebral injury is associated with relatively preserved language function with decreased visuospatial ability. However, previous reports of this phenomenon have examined patients with relatively large cerebral injuries (e.g., infantile hemiplegia) or limited sample sizes. METHODS: A total of 561 patients with complex partial seizures of left temporal lobe origin were studied. Patients were classified into left (n = 455), bilateral (n = 58), and right (n = 48) language dominant groups based on Wada testing. RESULTS: Right language dominant patients performed more poorly on multiple tests of visuospatial function, including Performance IQ (PIQ), than did left language patients. No significant group differences were detected for measures of language or general verbal function. The effects of bilateral language on PIQ differed according to handedness. Lowered PIQ was present in the bilateral nondextral group but not for bilateral dextral patients, and this pattern was observed with other visuospatial measures. CONCLUSIONS: In patients with relatively small lesions restricted to the left mesial temporal lobe, a shift in language dominance to the right hemisphere is associated with decreased visuospatial functions but preserved verbal abilities. Nondextral patients with bilateral language representation also displayed decreased visuospatial performance, although dextral patients with bilateral language did not.

Intractable nonlesional epilepsy of temporal lobe origin: lateralization by interictal SPECT versus MRI.

We performed a retrospective study of 53 consecutive "nonlesional" temporal lobectomy patients to assess the relative utility of MRI versus interictal single-photon emission computed tomography (SPECT) in this patient population. We compared the seizure lateralizing properties of MRI and SPECT using multiple blinded expert reviewers for both SPECT and MRI with a test-retest reviewer paradigm and measurements of hippocampal volume from MRI. The criterion standard for seizure lateralization was satisfactory postoperative seizure control (n = 43). The rate of correct seizure lateralization was significantly greater for MRI than for SPECT (p < or = 0.01), and the rate of incorrect lateralization was significantly less for MRI than for SPECT. The most accurate MRI measure was hippocampal volume measurements, which correctly lateralized the seizures in 86.0% of cases. The correct lateralization rate for SPECT was 45.4%. The MRI and SPECT studies tended to be noncomplementary with respect to seizure lateralization, and SPECT was likely to give an incorrect or indeterminate result in patients who were not lateralized by MRI. Concordant MRI-EEG lateralization was a strong predictor of satisfactory postoperative seizure control, while no relationship between postoperative seizure control and SPECT findings was present.

Neuropsychologic assessment in surgical treatment of epilepsy.

Neuropsychologic assessment has long been an integral part of evaluation for surgical treatment of epilepsy. Neuropsychologic evaluation and consultation continue to be an important part of the assessment for operative intervention for epilepsy, but the role of neuropsychology has changed over time. At one time, neuropsychologic assessment assumed a diagnostic role in preoperative evaluation for epilepsy and also contributed to the lateralization and localization of the seizure focus. Sophisticated electroencephalographic techniques and especially neuroimaging have revolutionized the diagnosis and management in epilepsy surgical treatment centers. Although still helpful, neuropsychology no longer has a major role in lateralization or localization of seizure onset. This report describes neuropsychologic evaluation and its current role in surgical treatment of epilepsy. The characteristics and purposes of neuropsychologic assessment and Wada testing (intracarotid injection of amobarbital) are described. Current research on assessment of emotional adjustment and on its predictors before and after surgical therapy for epilepsy is reviewed. Finally, the risk for neuropsychologic decline after temporal lobectomy is discussed in light of recent research on preoperative memory, hippocampal pathologic lesions, and quantitative neuroimaging data.

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.

Gender differences in post-temporal lobectomy verbal memory and relationships between MRI hippocampal volumes and preoperative verbal memory.

Thirty-three men and 42 women who underwent left, and 26 men and 24 women who underwent right temporal lobectomy (TL) were studied retrospectively to determine if there were sex differences in (1) verbal memory outcome, and (2) relationships between verbal memory and magnetic resonance imaging (MRI) hippocampal volumes. All patients were left hemisphere language dominant. The surgical specimen and MRI were consistent only with mesial temporal sclerosis (MTS). Verbal memory was evaluated by Logical Memory percent retention (LMPER) from the Wechsler Memory Scale-Revised (WMS-R). Women experienced a significant improvement while men experienced a significant decline in postoperative LMPER. The difference between right and left hippocampal volumes predicted verbal memory outcome in both men and women. Preoperative LMPER was positively correlated with both the left and right hippocampal volumes in left TL women only. No verbal memory sex differences or correlations between LMPER and MRI data were found in the right TL group. The data support the presence of human neurocognitive sexual dimorphism. Verbal memory abilities supported by the hippocampus are less lateralized in women with left temporal lobe epilepsy and mesial temporal sclerosis. Women appear to have greater verbal memory plasticity following early left mesial temporal lobe insult.

Quantitative MRI hippocampal volumes: association with onset and duration of epilepsy, and febrile convulsions in temporal lobectomy patients.

The relationships between preoperatively acquired MRI-based hippocampal volumes (HV), seizure disorder onset and duration, and early childhood febrile convulsions were investigated retrospectively with data from 72 left and 56 right temporal lobectomy patients. Patients with lesional pathology and heterotopic abnormalities were excluded. Age at development of spontaneous seizures unprovoked by an acute illness defined age of seizure disorder onset. Age of onset was subtracted from age at neurosurgery to determine duration. MRI variables included in this study were the right and left HV divided by total intracranial volume (RAHV, LAHV), and the right-left hippocampal difference (DHF). Partial correlations were used to better isolate relationships with onset of recurrent seizures corrected for age at surgery, and age at neurosurgery corrected for age of recurrent seizure onset. Partial correlations between age at neurosurgery and volume were not significant in either group. LAHV (r = 0.42, P < 0.0003) and DHF (r = -0.49, P < 0.0001) were correlated with age of onset in the left lobectomy group. Correlations in the right lobectomy group were not significant. The presence of a febrile convulsion was associated with smaller LAHV (F(1,70) = 10.54, P < 0.002) and larger DHF (F(1,70) = 11.36, P < 0.002) in left temporal lobectomy patients. The presence of a febrile convulsion in the right temporal group was associated with a slightly smaller DHF (F(1,56) = 5.90, P < 0.02), and slightly smaller RAHV (F(1,56) = 4.49, P < 0.04). These data suggest that hippocampal atrophy remains stable over the duration of temporal lobe onset seizure disorders, and is associated with early onset of recurrent seizures in left temporal patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Operative strategy in patients with MRI-identified dual pathology and temporal lobe epilepsy.

We performed a prospective study using preoperative magnetic resonance imaging to identify hippocampal formation atrophy in 15 consecutive patients with intractable partial epilepsy who had undergone a stereotactic resection of an extrahippocampal temporal lobe foreign-tissue lesion. A stereotactic lesionectomy was performed in all patients, i.e., only the imaging-defined lesion itself was resected. Hippocampal formation atrophy was identified in three of the 15 patients. Neuroimaging-detected hippocampal formation atrophy has been shown to be a reliable marker of moderate to severe mesial temporal sclerosis. All patients with hippocampal formation atrophy had an unfavorable operative outcome. Pathological examination of the hippocampus in one patient with neuroimaging-identified hippocampal formation atrophy who subsequently received an anterior temporal lobectomy revealed mesial temporal sclerosis. Nine of the 12 patients without hippocampal formation atrophy experienced a significant reduction in seizure tendency after lesionectomy. The surgically excised hippocampus in one patient without hippocampal formation atrophy who later underwent a temporal lobectomy showed no significant neuronal loss. Results of this study have modified the surgical approach taken at this institution in patients with temporal lobe lesional epilepsy. Patients with magnetic resonance imaging-defined dual pathology now undergo a temporal lobectomy which includes resection of the hippocampus and the foreign-tissue lesion.

MRI in the presurgical evaluation of patients with frontal lobe epilepsy and children with temporal lobe epilepsy: pathologic correlation and prognostic importance.

We performed magnetic resonance imaging (MRI) using a high-field strength magnet (1.5 T) in two series of 53 patients with intractable partial epilepsy of frontal lobe or temporal lobe origin who subsequently received ablative surgery for their seizure disorder. In the first series of patients the pathologic correlation and prognostic importance of an MRI-identified lesion in the frontal lobe were assessed. Twenty-five percent of the patients with negative MRI studies and 67% of patients with neuroimaging abnormalities restricted to the frontal lobe, were seizure-free at a minimum duration of follow-up of 1 year. None of the patients with a multilobar MRI-detected abnormality was seizure-free postoperatively. In the second study the sensitivity and specificity of MRI-based hippocampal volumetry was determined in pediatric patients with partial epilepsy of temporal lobe origin unrelated to foreign-tissue pathology. Hippocampal formation atrophy in the epileptic temporal lobe was identified in 63% of patients. The sensitivity and specificity of hippocampal volumetry was 100% in patients with mesial temporal sclerosis. The presence of an MRI-detected epileptogenic lesion in the frontal lobe and hippocampal formation atrophy in the temporal lobe may correlate with the underlying pathology and affect the identification of potential candidates for epilepsy surgery.

Temporal lobectomy in children: cognitive outcome.

OBJECT: The authors sought to determine the impact of early temporal lobectomy (in patients younger than age 17 years) on intellectual functioning. The efficacy of temporal lobectomy for treating seizures is well established and the procedure is becoming more acceptable as a treatment for children whose seizures are intractable. However, cognitive outcomes of temporal lobectomy in children and adolescents are largely unreported. The present study takes advantage of a unique multicenter collaboration to examine retrospectively intellectual functioning in a large sample of children who underwent temporal lobectomy. METHODS: Intellectual functioning was assessed before and after temporal lobectomy for treatment of medication-resistant seizures in 82 patients at eight centers of epilepsy surgery. All children underwent standard presurgical examinations, including electroencephalography-video monitoring, magnetic resonance (MR) imaging, and neuropsychological testing, at their respective centers. Forty-three children underwent left temporal lobectomy and 39 underwent right temporal lobectomy. For the entire sample, there were no significant declines in intelligence quotient (IQ) following surgery. Children who underwent left temporal lobectomy demonstrated no significant loss in verbal intellectual functioning and improved significantly in nonverbal intellectual functioning. Children who underwent right temporal lobectomy did not demonstrate significant changes in intellectual functioning. Although group scores showed no change in overall IQ values, an analysis of individual changes revealed that approximately 10% of the sample experienced a significant decline and 9% experienced significant improvement in verbal functioning. Significant improvement in nonverbal cognitive function was observed in 16% of the sample and only 2% of the sample showed significant declines. Risk factors for significant decline included older patient age at the time of surgery and the presence of a structural lesion other than mesial temporal sclerosis on MR imaging. CONCLUSIONS: The present study provides preliminary data for establishing the risk of cognitive morbidity posed by temporal lobectomy performed during childhood. With respect to global intellectual functioning, a slight improvement was significantly more likely to occur than a decline. However, there were several patients in whom significant declines did occur. It will be necessary to study further the factors associated with such declines. In addition, further study of more specific cognitive functions, particularly memory, is needed.

MRI hippocampal volume and neuropsychology in epilepsy surgery.

A review is provided of recent findings on relationships between neurocognitive test data and magnetic resonance imaging (MRI)-determined hippocampal volumes in nonlesional temporal lobectomy patients. The difference between the right and left hippocampal volumes is correlated with postoperative verbal memory in left temporal lobectomy patients who do not have lesional pathology. MRI hippocampal volume data are not associated with measures of executive functioning or naming. Sex differences have been found for verbal memory outcome as women have better verbal memory following left temporal lobectomy. Sex differences have also been found in the relationships between verbal and visual memory, and hippocampal volume data. The systematic combination of MRI-acquired morphological data and neuropsychological test data may further our understanding of neurocognitive function, and provide clinically useful data for counseling epilepsy surgery patients. The current data are promising with regard to prediction of memory outcome following temporal lobectomy, but they do not yet allow for prediction of specific individual patient outcomes. Rather, the currently available data support counseling patients based on the memory outcome of others with similar characteristics.

Intracarotid amobarbital procedure. The Wada test.

Wada testing has been a standard part of temporal lobectomy evaluation since the early 1960s. Although the procedure was initially used to lateralize language function, it was soon modified to assess risk for postoperative amnesia. The use of the procedure has now evolved to include prediction of degrees of memory decline. This use has been criticized, but more recent research has better described important parameters of the procedure and supported its validity. The Wada test is effective in lateralizing seizure onset, predicting postoperative seizure control, and predicting degree of verbal memory decline following left temporal lobectomy. The validity of Wada test data has also been supported by correlations between Wada memory performance and hippocampal pyramidal cell loss or MR imaging determined hippocampal volumes. It remains to be seen, however, if Wada memory performance and data from other sources such as MR imaging, ictal SPECT, positron emission tomography, or functional MR imaging are redundant or independently contribute to patient diagnosis and management.

Long-term cognitive outcomes following out-of-hospital cardiac arrest: a population-based study.

OBJECTIVE: To report the neurologic outcomes in long-term survivors of out-of-hospital cardiac arrest with ventricular fibrillation as the presenting rhythm (OHCA VF) at a population level. METHODS: All adults who experienced OHCA VF in Olmsted County, MN, from 1990 to 2008, survived more than 6 months postarrest, and were alive at the time of study recruitment were invited to participate in structured neuropsychological testing and a neurologic examination. Cognitive test results were compared to the normal population using the Mayo's Older Adults Normative Studies. Linear regression models were fit to evaluate each neuropsychological test result in relation to call-to-shock time, sex, age at cardiac arrest, time elapsed since event, witnessed vs unwitnessed arrest, and administration of bystander cardiopulmonary resuscitation. RESULTS: Of 332 OHCA VF arrests, 140 people (42.2%, 95% confidence interval 36.9%-47.5%) survived to discharge. No patient entered a minimally conscious or permanent vegetative state. Long-term survivors (n = 47, median survival 7.8 years postarrest) had lower scores on measures of long-term memory and learning efficiency (p = 0.001) but higher than average scores on verbal IQ (p = 0.001). Nearly all survivors were functionally independent and scored high on the Mini-Mental State Examination (MMSE) (median Barthel Index 100/100, median MMSE 29/30). CONCLUSIONS: Long-term survivors of OHCA VF have long-term memory deficits compared to the normal population at the same age and education level. These findings provide a baseline for cognitive outcomes studies of OHCA VF as new techniques are developed to improve survival.

Neurologic manifestations in welders with pallidal MRI T1 hyperintensity.

BACKGROUND: Neurologic symptoms have been attributed to manganese fumes generated during welding. Increased T1 MRI signal in the basal ganglia is a biologic marker of manganese accumulation. Recent studies have associated welding and parkinsonism, but generally without MRI corroboration. OBJECTIVE: To characterize the clinical and neuropsychological features of patients with MRI basal ganglia T1 hyperintensity, who were ultimately diagnosed with neurotoxicity from welding fumes. METHODS: The medical records of welders referred to the Department of Neurology with neurologic problems and basal ganglia T1 hyperintensity were reviewed. RESULTS: All eight patients were male career welders with increased T1 basal ganglia signal on MRI of the brain. Several different clinical syndromes were recognized: a parkinsonian syndrome (three patients), a syndrome of multifocal myoclonus and limited cognitive impairment (two patients), a mixed syndrome with vestibular-auditory dysfunction (two patients), and minor subjective cognitive impairment, anxiety, and sleep apnea (one patient). Neuropsychometric testing suggested subcortical or frontal involvement. Inadequate ventilation or lack of personal respiratory protection during welding was a common theme. CONCLUSIONS: Welding without proper protection was associated with syndromes of parkinsonism, multifocal myoclonus, mild cognitive impairment, and vestibular-auditory dysfunction. The MRI T1 hyperintensity in the basal ganglia suggests that these may have been caused by manganese neurotoxicity.

MAPI code types in an inpatient crisis-unit sample.

Limited data is available concerning the use of the Millon Adolescent Personality Inventory (MAPI; Millon, Green, & Meagher, 1982) and high-point code combinations of its personality style scales. Our study reports on the frequency of high-point codes in an inpatient crisis-unit sample. Data analyses comparing personality style codes using MAPI expressed concerns scale elevations and Rorschach data are reported. Results comparing the personality style codes and expressed concerns scales were consistent with the findings of Millon et al. (1982). Analyses comparing Rorschach and MAPI data revealed only the presence or absence of vista responses as having any appreciable relationship to MAPI codes or personality scales.

Learned helplessness, attributional style, and depression in epilepsy. Bozeman Epilepsy Surgery Consortium.

PURPOSE: We wished to examine the relevance of the theory of learned helplessness in general, and attributional style in particular, to the understanding of depression among patients with epilepsy. METHODS: Patients with lateralized temporal lobe epilepsy (TLE) (right = 73, left = 70) were administered two self-report depression inventories [Beck Depression Inventory (BDI), Center for Epidemiological Studies-Depression scale (CES-D)]. Depression scores were examined in relation to a key component of the revised theory of learned helplessness (attributional style) using the Optimism/Pessimism Scale. RESULTS: Attributional style was significantly associated with increased self-reported depression and remained significant when the effects of several confounding variables were controlled [age, age at onset, laterality of TLE, sex, and method variance]. CONCLUSIONS: The results indicate that the concept of learned helplessness in general, and attributional style in particular, are related to the genesis of depression in epilepsy. Because they are known to be related to depression in the general population, and because specific techniques for intervention and prevention are available, greater consideration of learned helplessness and attributional style in the genesis of depression in epilepsy may be worthwhile.

The utility of the MAPI in the assessment of depression.

The relationships between the Millon Adolescent Personality Inventory (MAPI; Millon, Green, & Meagher, 1982) and depression, as assessed by the Multiscore Depression Inventory (MDI; Berndt, 1968) were examined. Elevations on the MDI subscales were positively related to elevations on MAPI personality style Scale 2 (Inhibited) and Scale 8 (Sensitive) and on six of the eight MAPI expressed concerns scales. MAPI personality style Scale 4 (Sociable) and Scale 5 (Confident) were negatively correlated with the MDI. MAPI code types containing either Scale 2 or 8 were associated with a high MDI full-scale score. The subjects who received a MAPI computer-generated diagnosis of borderline personality disorder also had elevated MDI full-scale scores. The findings of this study appear consistent with the existing body of MAPI research, and the data suggest that the MAPI personality style scales may have both state and trait qualities.

California Verbal Learning Test (CVLT) performance in severely head-injured and neurologically normal adult males.

California Verbal Learning Test (CVLT) performance was compared for 33 head-injured and 33 neurologically normal adult males. On learning trials, head-injured persons recalled fewer items than controls in general, though the percent of improvement between trials did not differ for these groups. Head-injured patients also demonstrated more intrusions and used semantic groupings less than did normal controls during learning trials. On delayed recall trials, head-injured persons remembered a smaller percentage of items they had learned earlier than did controls. Semantic cues aided recall for head-injured but not normal persons. Head-injured persons were less able to discriminate list from nonlist items during the recognition trial. Results indicated both retrieval and storage (i.e., encoding or retention) deficits for the head-injured group. The CVLT is a useful instrument for defining memory deficits in a head-injured population.