Seizure prediction and recall.

Using separate generalized mixed-effects models, we assessed seizure recall and prediction, as well as contributing diagnostic variables, in 83 adult patients with epilepsy undergoing video/EEG monitoring. The model revealed that when participants predicted a seizure, probability equaled 0.320 (95% CI: 0.149-0.558), a significant (P<0.05) increase over negative predictions (0.151, 95% CI: 0.71-0.228]). With no seizure, the rate of remembering was approximately 0.130 (95% CI: 0.73-0.219), increasing significantly to 0.628 (95% CI: 0.439 to 0.784) when a seizure occurred (P<0.001). Of the variables analyzed, only inpatient seizure rate influenced predictability (P<0.001) or recollection (P<0.001). These models reveal that patients were highly aware of their seizures, and in many cases, were able to make accurate predictions, for which seizure rate may be an important factor.

Anomalous dominance and persistent tardive dyskinesia.

We examined handedness and cerebral hemispheric asymmetries on computed tomography (CT) scan in a sample of schizophrenic patients who were rated also for the presence or absence of persistent tardive dyskinesia (TD). Patients with TD showed a more standard dominance pattern, with dextral hand preference and normal occipital asymmetry. Anomalous dominance was associated with a marked underrepresentation of TD. Stepwise discriminant analyses indicated that the statistical prediction of TD was enhanced by the inclusion of dominance measures. Schizophrenic patients with strong standard dominance patterns may be more susceptible to developing TD, or conversely, anomalous dominance may confer protection against TD.

Postictal and chronic psychoses in patients with temporal lobe epilepsy.

OBJECTIVE: This study sought to elucidate the relation of clinical, neuropsychological, and seizure variables to chronic and postictal psychoses in patients with temporal lobe epilepsy. METHOD: Forty-four patients with treatment-refractory temporal lobe epilepsy were given formal psychiatric evaluations; 29 patients had no psychiatric disorder or a nonpsychotic disorder, eight patients had postictal psychoses, and seven patients had chronic psychoses. Comparisons of clinical, neuropsychological, magnetic resonance imaging, and seizure variables were made between the nonpsychotic and the psychotic patients and, secondarily, between the patients with transient postictal psychoses and those with chronic psychoses. RESULTS: Bitemporal seizure foci, clustering of seizures, and absence of febrile convulsions were associated with both postictal psychoses and chronic psychoses. Younger age at onset of epilepsy and lower verbal and full-scale IQs differentiated the patients with chronic psychoses from those with postictal psychoses. CONCLUSIONS: Patients with temporal lobe epilepsy with chronic and postictal psychoses show similar profiles of clinical and seizure variables, suggesting shared etiologic factors. These factors may increase the propensity to develop psychotic symptoms, while other factors, such as time of onset of epilepsy and underlying neuropathology, may determine whether transient or chronic psychotic symptoms develop. Even among patients with treatment-refractory temporal lobe epilepsy, a specific subgroup of patients, characterized by bitemporal seizure foci, an absence of febrile convulsions, and a history of clustering of seizures, appears to be particularly prone to develop psychotic disorders. A process similar to secondary epileptogenesis may be involved in the development of the psychoses.

Cerebellar atrophy in patients with long-term phenytoin exposure and epilepsy.

OBJECTIVE: Cerebellar atrophy has been noted in patients with phenytoin exposure. This finding has been attributed by some investigators to seizures, but by others to phenytoin. Previous studies included patients with mental retardation and convulsive seizures. We undertook a study in a group of nonretarded patients with partial epilepsy to better elucidate the cause of the cerebellar atrophy. DESIGN: Case control study. SETTING: Referral population from an epilepsy center. PATIENTS: Thirty-six patients with partial epilepsy and long-term phenytoin exposure were selected from a consecutive sample of admissions to an epilepsy center. Patients with histories of ethanol abuse, perinatal distress, anoxia, status epilepticus, or neurodegenerative disorders were excluded. Age- and sex-matched controls were selected from a pool of healthy volunteers and patients who had undergone magnetic resonance imaging for complaints of headache and dizziness. INTERVENTIONS: All patients and controls underwent magnetic resonance imaging. MAIN OUTCOME MEASURE: Degree of cerebellar atrophy. RESULTS: The magnetic resonance imaging scans were reviewed in a blind fashion. A rating was assigned to each scan based on the degree of cerebellar atrophy. Cerebellar atrophy was significantly more pronounced in patients than in controls. No correlation was found between cerebellar atrophy and variables reflective of seizure severity or degree of phenytoin exposure. CONCLUSIONS: Cerebellar atrophy may be seen in phenytoin-exposed patients with epilepsy in the absence of generalized tonic-clonic seizures or preexistent brain damage. Whether it is the phenytoin or the seizures that play the primary etiologic role remains unanswered. These factors may be synergistic.

New-onset psychogenic seizures after surgery for epilepsy.

BACKGROUND: The emergence of psychogenic seizures after surgery for epilepsy is not well recognized. OBJECTIVES: To identify the frequency of psychogenic seizures in an 11-year surgical experience and to characterize the patients with this complication. METHODS: Ninety-six patients underwent surgery for epilepsy between 1985 and 1996. The surgical database was reviewed and all patients who experienced postoperative psychogenic seizures were identified. Patients were characterized by sex, age, psychopathologic conditions, full-scale IQ, duration of epilepsy, surgical procedure, and operative complications. Patients were compared with the surgical group as a whole for these variables. SETTING: A comprehensive epilepsy center. RESULTS: Five patients were identified: 3 men and 2 women. Mean full-scale IQ was 73 (range, 66-82). Mean age was 29.8 years (range, 22-36 years). Three patients were diagnosed as having psychosis, 1 with borderline personality disorder and 1 with generalized anxiety. Operations included 4 anterior temporal lobectomies and 1 occipital lobectomy. Two patients experienced operative complications. Compared with the surgical cohort, patients had a higher frequency of preoperative psychopathologic conditions, lower mean full-scale IQ, and a greater occurrence of operative complications. CONCLUSIONS: (1) Patients can develop new-onset psychogenic seizures after surgery for epilepsy. (2) Low full-scale IQ, serious preoperative psychopathologic conditions, and major surgical complications may be risk factors. (3) Atypical postoperative seizures should be evaluated with video electroencephalographic monitoring before concluding that they are epileptic.

Regional distribution of cerebral arteriovenous malformations. Interactions with sex and handedness.

On the basis of clinical observation and a developmental theory of cerebral laterality, Geschwind and Galaburda suggested that cerebral arteriovenous malformations (AVMs) are more common in the left hemispheres of male patients. We tested this hypothesis by examining interactions among sex, handedness, and location of lateralized, supratentorial AVMs. Data from 112 cases were analyzed by log-linear procedures. We found that (1) females had a greater proportion of left-hemisphere AVMs, whereas males showed an opposite trend; (2) there were no interactions between sex and handedness; and (3) nondextrals showed a higher proportion of AVMs located in frontal regions, regardless of the hemispheric side of the lesion. Although these findings appear to be inconsistent with the Geschwind-Galaburda hypothesis, the inconsistency may be attributable to the embryonic stage at which this developmental abnormality occurs. In addition, the unexpected findings may also reflect our use of multivariate statistical procedures, which control for interaction effects.

Epileptic aphasia.

We document a case of isolated epileptic aphasia with clear correlation between episodic clinical and electrographic events. This disorder is rarely recognized, perhaps because it is obscured by ictal motor activity or speech arrest, or by the lack of clinical manifestations if the seizure occurs when the patient is not attempting to speak.

Cerebral metabolic topography in unilateral temporal lobe epilepsy.

OBJECTIVE: Fluorodeoxyglucose positron emission tomography (FDG-PET) studies of temporal lobe epilepsy (TLE) generally report interictal hypometabolism in the vicinity of the seizure focus. Yet, other evidence suggests that interictal metabolic abnormalities might extend to remote brain areas. We used FDG-PET to evaluate metabolism in selected regions distant from the focus in TLE. SUBJECTS: Twenty adult patients with medically intractable TLE were selected by criteria favoring a unilateral mesiobasal temporal focus. Structural imaging in this sample were normal except for medial temporal sclerosis in 13 patients. Twenty normal volunteers were controls. DESIGN: PET imaging was performed interictally. Regional glucose metabolism normalized by global metabolism was analyzed using t tests and correlation analysis. RESULTS: Ipsilateral to the seizure focus, metabolism was depressed compared with normal in the temporal pole (p = 0.001), but relatively elevated in the mesiobasal region (p = 0.005). Contralateral to the focus, metabolism was elevated in lateral temporal cortex (p = 0.0003) and mesiobasal regions (p = 0.0001). Metabolic correlation between ipsilateral and contralateral mesiobasal regions was similar in normal subjects (r = 0.74) and patients (r = 0.68). In contrast, correlations were abnormal between temporal poles and other temporal lobe subregions, both ipsilateral and contralateral to the seizure focus. CONCLUSIONS: Relative to normal values, both elevations and depressions of metabolism exist interictally in TLE. Such abnormalities, and accompanying changes in interregional correlations, may have wide spatial distribution. These findings are atypical among PET studies but are consistent with other physiologic, anatomic, and neuropsychological investigations of TLE.

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.

Retrograde amnesia following unilateral temporal lobectomy.

Remote memory performance was assessed in a carefully matched sample of temporal lobectomy subjects and normal controls. Left temporal lobectomy subjects exhibited a consistent pattern of remote memory disturbance. Right temporal lobectomy subjects performed at the same level as normal controls. The pattern of impairment observed in left temporal lobectomy subjects was characterized by deficits in recall of chronological information from the past decade and extended to deficits in recall in some aspects of factual knowledge. The disorder could not be attributed solely to language deficits and was at least as severe as accompanying deficits in recent memory. These findings suggest that the left medial temporal region may play a significant role in recall of remote information in addition to its role in recent memory functions.

Memory functioning in Lyme borreliosis.

BACKGROUND: To objectively measure memory functioning in patients with Lyme borreliosis and examine the relationship between subjective reports of memory dysfunction and actual impairment. METHOD: A prospective pretreatment study of patients with Lyme borreliosis (N = 21), a patient control group (osteomyelitis, N = 21), and healthy controls (N = 21) was conducted by using tests of verbal memory functioning (California Verbal Learning Test) and self-reported depression (Beck Depression Inventory-Cognitive Index), fatigue (Fatigue Severity Scale), and subjective ratings of memory abilities (Self-Rating Scale of Memory Functions). RESULTS: Patients with Lyme borreliosis performed worse than healthy controls on verbal memory testing, but did not perform significantly differently from patient controls. Lyme borreliosis patients reported increased fatigue, which was correlated with poorer memory performance. Although the Lyme borreliosis patients rated their memory as more impaired, subjective complaints were not correlated with objective memory scores. CONCLUSION: These findings suggest impaired memory performance is not specific to Lyme borreliosis and may be a result of evaluating cognitive functioning in patients with physical illness and somatic complaints. Fatigue is a prominent presenting complaint in patients with Lyme borreliosis and needs to be controlled for since it is known to influence neuropsychological performance. Subjective complaints are not correlated with objective memory assessment, so self-report of memory impairment should not be the criterion for inclusion in studies investigating cognitive manifestations of Lyme borreliosis.

Schizophrenia and attention deficit disorder. Two complex disorders of attention.

Attentional dysfunction can be found in nearly every form of psychopathology, not just in attention deficit disorder (ADD). Being able to distinguish ADD from other psychiatric conditions is crucial for clinicians working with adolescents and young adults, particularly in the case of psychoses where making the correct diagnosis and beginning treatment promptly is extremely important. In this paper we review the literature on the attentional dysfunction found in schizophrenia and compare it to that found in ADD in an effort to increase our knowledge of etiology and underlying mechanisms. Investigators studying ADD may learn from the study of schizophrenia by realizing that ADD is also a complex disorder of attention that occurs across the developmental spectrum and is characterized by various predispositional, environmental, and maturational factors.

Three-dimensional fast low-angle shot imaging and computerized volume measurement of the hippocampus in patients with chronic epilepsy of the temporal lobe.

This study investigated the use of three-dimensional fast low-angle shot (FLASH) imaging and computer-assisted morphometry for identifying hippocampal changes associated with unilateral temporal lobe seizures. Contiguous 3.1-mm coronal FLASH images were obtained in 28 patients with electroencephalographically verified left (n = 17) or right (n = 11) temporal lobe seizures and 28 age- and sex-matched control subjects. Hippocampal volumes were calculated with the use of a computerized mensuration system developed for detailed morphometric assessment. The results of a multivariate analysis of variance revealed a significant group difference by hemisphere interaction (F = 26.3, p less than .001). Significant reductions in left hippocampal volume (32%, p less than .001) were exhibited in patients with left temporal lobe seizures, and significant reductions in right hippocampal volume (35%, p less than .001) were seen in patients with right temporal lobe seizures. A discriminant analysis with the use of left and right hippocampal volumes classified patients with left temporal lobe seizures with 94% sensitivity and 73% specificity and patients with right temporal lobe seizures with 89% sensitivity and 94% specificity. The results of this study demonstrate that unilateral temporal lobe seizures are accompanied by significant reductions in hippocampal volume ipsilateral to the seizure focus. The use of FLASH imaging and computer-assisted morphometry of the hippocampus appears to provide valuable structural information for confirming the laterality of the electroencephalographic seizure focus.

The roles of semantic networks and search efficiency in verbal fluency performance in intractable temporal lobe epilepsy.

Two competing hypotheses (i.e., disruption of semantic networks vs. search inefficiency) concerning the mechanisms underlying impaired semantic verbal fluency in temporal lobe epilepsy (TLE) were tested within a single paradigm. Reports that semantic verbal fluency is more impaired in left than right TLE groups were confirmed by the findings that the left TLE group produced fewer words on a supermarket fluency task than did the normal control (NC) group, and that the performance of the right TLE group was intermediate to that of the left TLE and NC groups. Because both TLE groups generated fewer words per category of supermarket items sampled, and produced a higher ratio of category labels relative to category exemplars than did the NC group, it can be surmised that TLE disrupts semantic memory networks. The findings did not support the competing hypothesis that reduced semantic verbal fluency in TLE is a manifestation of inefficient search/retrieval strategies, possibly associated with distal frontal lobe pathophysiology. Specifically, the TLE and NC groups did not differ significantly in their mean number of perseverations, intrusions, or search efficiency (operationalized as the ratio of the number of shifts between categories to the number of categories sampled).

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.

The neuropsychology of schizophrenic speech.

Recent interest in the biological basis of schizophrenia has led to a reexamination of many symptomatic aspects of the disorder in terms of brain-behavioral models. Schizophrenic speech disturbances have traditionally been described in terms of a model of acquired aphasia. We review some of the limitations of this model and provide an alternative model for the study of some characteristics of schizophrenic speech based on neuropsychological theories of frontal lobe dysfunction in schizophrenia. The emphasis is placed on the study of productive errors noted in schizophrenic speech, most notably verbal perseverations. In a study of errors observed during a sample of 15 schizophrenics performance on a confrontation naming test, we were able to reliably identify and classify hierarchic categories of verbal perseverations occurring at both semantic and phonemic levels. These perseverations constituted 20% of the total errors. We argue that these perseverations represent a special case of executive dysfunction resulting from a disturbance of language monitoring mechanisms. We examine the implications of these findings for a hypothesis of schizophrenic speech disturbances in terms of frontal lobe dysfunction and the developmental neuropathological processes involved in the illness.

Long-term association between seizure outcome and depression after resective epilepsy surgery.

OBJECTIVE: This study explored the association between long-term epilepsy surgery outcome and changes in depressive symptoms. METHODS: Adults were enrolled between 1996 and 2001 in a multicenter prospective study to evaluate outcomes of resective epilepsy surgery. The extent of depressive symptoms and depression case status (none, mild, or moderate/severe) were assessed using the Beck Depression Inventory (BDI) preoperatively and 3, 12, 24, 48, and 60 months postoperatively. A mixed-model repeated-measures analysis was performed, adjusting for covariates of seizure location, gender, age, race, education, and seizure control. RESULTS: Of the total 373 subjects, 256 were evaluated at baseline and 5 years after surgery. At baseline, 164 (64.1%) were not depressed, 34 (13.3%) were mildly depressed, and 58 (22.7%) had moderate to severe depression. After 5 years, 198 (77.3%) were not depressed, 20 (7.8%) were mildly depressed, and 38 (14.8%) were moderately to severely depressed. Five years after surgery, the reduction in mean change from baseline in BDI score was greater in subjects with excellent seizure control than in the fair and poor seizure control groups (p = 0.0006 and p = 0.02 respectively). Those with good seizure control had a greater reduction in BDI score than the poor seizure control group (p = 0.02) and borderline significant reduction compared with the fair seizure control group (p = 0.055). CONCLUSION: Although study participants had initial improvement in depressive symptoms, on average, after resective surgery, only patients with good or excellent seizure control had sustained long-term improvement in mood.

Reliable change indices and regression-based measures for the Rey-Osterreith Complex Figure test in partial epilepsy patients.

The Rey-Osterreith Complex Figure (ROCF) is commonly used in evaluations of patients undergoing epilepsy surgery. We assessed test-retest performance on ROCF in 30 partial epilepsy patients (mean interval = 33.7 months) to derive reliable change indices (RCIs) and regression-based measures for change. ROCF reproductions were rescored by three raters (IRR Copy: 0.963; Delayed Recall: 0.986). The derived adjusted RC (90% CI) cutoff values for the ROCF Copy were (or=8.4) and were (or=10.0) for the Delayed Recall. Results from regression-based analyses were negative, using age, education, seizure duration, and age of onset, whereas a baseline score was a significant predictor of a follow-up score. The results provide a means to evaluate long-term outcome in epilepsy patients using the ROCF.