Left Temporal Lobe Dysfunction Research Articles

36 Naming in Monolingual and Bilingual Children with Epilepsy

Objective:Word finding or “naming” difficulty is a symptom of multiple neurological disorders; therefore, naming assessment is an integral component of neuropsychological evaluation. Prior work has found weaker second-language naming in healthy proficient bilingual youth than monolingual youth, and similar findings have been shown in adults with epilepsy. Considering the potential influences of both early onset epilepsy and bilingualism on brain development, we compared naming in English second language (ESL) and monolingual youth with epilepsy. To assess the impact of bilingualism independent of the known effects of seizure laterality (i.e., poor naming in those with left, dominant-hemisphere seizures), we excluded patients with left language dominance and unilateral seizures. We hypothesized that like other groups, naming would be weaker in ESL than in monolingual youth with epilepsy.Participants and Methods:Participants included 84 children with seizures that could not be lateralized clinically (n=36), bilateral seizures (n=20), centrotemporal spikes (n=3), and those with unilateral seizures and atypical language dominance (n=25), ages 6-15 years old: 66 monolingual, English (mean age: 10.87 ± 2.70 years) and 18 ESL (mean age: 10.78 ± 2.88 years). Those with FSIQ < 70 and vocabulary SS < 6 were excluded to ensure English proficiency. Independent samples t-tests, multivariate ANOVA, and chi-square tests compared groups on demographic factors and test performance. All measures (FSIQ, WISC/WASI Vocabulary, letter and category fluency, Children’s Auditory (AN) and Visual Naming (VN) Tests) were administered in English.Results:Monolingual and ESL groups did not differ in: age, sex, SES, seizure type (i.e., non-lateralized, bilateral, centrotemporal spikes, or atypical language dominance), epilepsy onset age, or number of AEDs. Comparisons also showed no differences in FSIQ, vocabulary, letter fluency, or category fluency (all ps > 0.05). By contrast, auditory and visual naming performances were weaker among ESL patients than monolingual patients: AN accuracy, F(1,81) = 10.89, p = 0.001; AN tip-of-the-tongues (TOTs), F(1,81) = 6.35, p = 0.014; AN Summary Scores (SS), F(1,81) = 6.17, p = 0.015; VN accuracy, F(1,81) = 4.66, p = 0.034; VN SS, F(1,81) = 4.87, p = 0.030, with the exception of VN TOTs, which approached significance, F(1,81) = 3.55, p = 0.063.Conclusions:Consistent with findings in bilingual healthy youth and ESL adults with epilepsy, naming in ESL youth with epilepsy was weaker than in monolingual children. The groups did not differ on other aspects of language. Thus, unlike other expressive verbal functions, naming is adversely affected in the second language of bilingual people with epilepsy across the age span. These results suggest that poor naming in ESL patients cannot be used to infer a naming deficit, and/or left (dominant) temporal lobe dysfunction.

Event-related potentials reveal visual episodic memory deficits in patients with temporal lobe epilepsy

ObjectiveTemporal lobe epilepsy (TLE) patients usually suffer from impaired episodic memory (EM), but its underlying electrophysiologic mechanism and impacted cognitive performance are unclear. We aim to investigate the association between episodic memory reserve and physiological measures of memory workload in TLE patients using Event-related potentials (ERP). MethodsA change detection task with image stimuli assesses visual episodic memory. During the memory encoding and decoding phases, the ERP signals were analyzed from twenty-nine TLE patients (twelve with left TLE patients, seventeen with TLE), and thirty healthy controls. Given that EM is a complex process involving many fundamental cognitive processes, the amplitudes and latencies of EM-related ERP (FN400, late positive potential (LPC), and late posterior negativity (LPN)), and the ERP reflecting the fundamental processes (P100, N100, P200, and P300) were calculated. Then we used a three-by-two factorial design on the ERP metrics for interaction and main effects. The correlation analysis among Wechsler Memory Scales-Chinese Revision (WMS-RC) results, behavioral data, and the ERPs was carried out. ResultsThe TLE patients performed worse in WMS-RC and the memory task. The increased P200 and decreased P300 amplitudes were observed in the TLE patients, and LPN was abnormal in only LTLE patients. For EM-related components, differences were observed in both the LTLE and RTLE patients: the lack of the FN400 effect, the lack of the reversed LPC effect, and the reduced FN400. No significant inter-group difference was detected for the latencies of all the ERPs. Additionally, there were significant correlations among WMS-RC scores, behaviors, and some ERP amplitudes. ConclusionsThe impaired EM is linked to the increased P200 and decreased P300 amplitudes. LPN seems to be sensitive to left temporal lobe dysfunction. More importantly, the abnormal old or new effects of the FN400 and LPC, and the reduced FN400 amplitude might be associated with the visual EM deficit in the TLE patients. These findings may assist in the deep understanding of the EM disorder and the evaluation of the side effects of antiepileptic drugs.

A 67-year-old man with cognitive decline incidentally diagnosed with gastric submucosal tumor

Introduction.–Vitamin B12 deficiency can lead tomemory loss, disorientation and dementia is well known from the past. Therefore when we first meet the patient who have cognitive decline, we must check the Vitamin B12 level. Methods and results.– A 67-year-old man visited our clinic with cognitive decline. He had no specific past history of illness. Two years ago, memory complaint was started. His neuropsychological test showed both frontal and left temporal lobe dysfunction. His educationwas 16years. Korean-MiniMental State Examination (KMMSE) score was 26 and Clinical Dementia Rating (CDR) score was 0.5. And sum of box score was 4. He was in mild dementia state. The routine lab tests revealed that he had vitamin B12 deficiency. Vitamin B12 level was 45pg/mL and homocysteinwas 83.8umol/L. His hemogoblin was 13.3 g/dL. Antiparietal cell antibody(Ab) was positive and anti intrinsic factor Abwas negative. Gastrin level was increased. Under the esophagogastroduodenoscopy, there was no evidence of atrophic gastritis but gastric submucosal tumor was found. If the autoimmune gastritis was in chronic state, atrophic gastritismight be found. Usually after chronic stage of autoimmune gastritis, gastric cell dysplasia and submucosal tumor can occur. But in this case, there was no anemia and no atrophic gastritis. It suggests his hypovitaminosis B12 state has not been that long. Conclusions.– Whether his submucosal tumor was due to autoimmune gastritis or incidental growth, it was a unique case who did not have pernicious anemia and atrophic gastritis have a gastric submucosal tumor.

A critical evaluation of the lateralizing significance of material-specific memory deficits in patients with mesial temporal lobe epilepsy with hippocampal sclerosis

To critically assess the value of material-specific memory deficits in lateralizing temporal lobe dysfunction preoperatively, we compared the neuropsychological data of 50 consecutive patients with unilateral mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS; right: 31, left: 19) with those of 50 age- and education-matched healthy control subjects. On case-control comparison, both the subcohorts with left and right MTLE-HS performed poorly on intelligence tests, in addition to individual memory tests. However, comparison of the verbal and visual memory functions between subcohorts with right and left MTLE-HS revealed that learning trials and delayed word list recall were the only tests that hypothesized left temporal lobe dysfunction. We conclude that material-specific memory deficits are largely test driven, but there is a lateralizing role for task-specific deficits in left MTLE-HS. Although neuropsychological data help to define baseline neuropsychological impairment, caution should be exercised in interpreting the lateralizing value of material-specific memory deficits prior to surgery.

Progressive cerebroretinal microangiopathy with calcifications and cysts syndrome: An unusual cause of complex partial seizure

PROGRESSIVE CEREBRORETINAL MICROANGIOPATHY syndrome is characterized by cerebral calcification and cyst formation (CRMCC), as defined in recent years,1 and is described in the published reports as Coats plus syndrome, Labrune syndrome and leukoencephalopathy calcification and cysts (LCC) syndrome.2 Cerebral, ophthalmic, skeletal, intestinal involvement can be seen. CRMCC determined in late adolescence is limited. Autosomal recessive inheritance is reported.3 In the majority of patients, neurological findings showing progression have been reported, such as spasticity, dystonia, ataxia and loss of cognitive abilities. Imaging findings with laboratory data should support the diagnosis.4 The case presented here is of a 20-year-old male patient whose indications began in late adolescence and were defined as CRMCC characterized by central nervous system involvement. The patient had a history of febrile convulsions at the age of 2, and until 20 years old had suffered no seizures. He started to have complex partial seizure (CPS) with an aura of loss of speech and extremity numbness followed by extremity spasms accompanied by spasm of the head and neck area, versive rotation movements and manual automatisms after 20 years of age. Familial inheritance was not shown. The neurological and ophthalmological examination was normal. There were no psychiatric, psychological or behavioral problems besides CPS. Memory disturbance due to left temporal lobe dysfunction was determined by the Wechsler Memory Scale (WMS) psychometric tests. Under observation in the video electroencephalography monitorization unit, CPS were seen three times. Seizures lasting up to 1 min were observed, before the seizure, showing a defining aura of loss of speech and numbness on the right side of the body, while during the seizure he had a behavioral arrest, his head was versive turned to the right and there were oral-alimentary and bilateral manual automatisms. Spike, sharp and slow wave activities were observed starting from the left frontal region and emitting to the temporal region during the seizure. For this reason, the seizure from the left frontal region and spread to the left temporal region was concluded. Computed tomography showed multiple calcified foci in the cyst wall, basal ganglia, thalami and cerebral white matter. Magnetic resonance (MR) imaging revealed signal abnormalities in the cerebral white matter, and a right thalamo-caudate cyst and a smaller pontine cyst. There was no restriction of diffusion-weighted MR images. MR spectroscopy demonstrated minimal increase in the choline peak, mild decrease in the N-acetylaspartate peak, and a lactate peak. Serology positive data were not determined. CRMCC cases generally show indications at an early age and the number of cases determined in late adolescence and older is relatively limited. Cases may present with different clinical tables related to the system involvement. To the best of our knowledge, cases of CRMCC-related complex partial seizures have not been reported. In the radiological imaging data of CRMCC syndrome as leukoencephalopathy (demyelinization and white matter edema), calcification and cyst formation were found. It is a syndrome which may accompany retinal microangiopathy. A differential diagnosis of CRMCC should be considered for cases presenting with CPS and radiological imaging findings. The patient gave the authors written informed consent to publish this report. We would like to thank Patricia E. Miller, University of Rochester Medical Center, NY, USA.

The Story Learning and Memory (SLAM) test: Equivalence of three forms and sensitivity to left temporal lobe dysfunction

Remembering meaningful information is an important component of verbal memory. However, findings from existing story memory tests have been mixed in patients with temporal lobe epilepsy (TLE). We developed a test, the Story Learning and Memory (SLAM) test, in which a story is presented repeatedly until a performance criterion is reached, and verbatim recall is obtained only once, after a delay. In Study 1 we demonstrated a significant learning deficit in patients with left, but not right, TLE, and they were further impaired in retention of the story despite having learned it to the same criterion as subjects with right TLE and healthy subjects. These deficits remained confined to patients with left TLE after surgery. For clinical use we developed the SLAM in three versions in two languages; in studies 2 and 3 we tested and proved their equivalence.

Persistent Auditory Hallucinations That Are Unresponsive to Antipsychotic Drugs

Persistent Auditory Hallucinations That Are Unresponsive to Antipsychotic Drugs

Altered hemispheric asymmetry and positive symptoms in schizophrenia: equivalent current dipole of auditory mismatch negativity

The abnormality of mismatch negativity (MMN) in schizophrenia is thought to be associated with perceptional disturbance and cognitive dysfunction. The purpose of the present study was to investigate the change of the normal functional hemispheric lateralization in schizophrenia by employing the equivalent current dipole (ECD) model of auditory MMN with individual MRI and high-density electroencephalography (EEG). The MMNs resulting from auditory stimuli with passive oddball paradigm in a group of schizophrenics ( n=15), and also a group of age-, sex-, and handedness-matched normal controls, were recorded by 128 channel EEG. The location and power of ECD sources at the peak point were calculated. Individual 3-D brain magnetic resonance images (MRI) were used for realistic head modeling and for source localization. For both groups, the MMN source was determined to be located in the superior temporal gyrus (STG). However, the normal functional hemispheric asymmetry of ECD power was significantly altered in the schizophrenics ( χ 2 test=16.13, p<0.001). Left MMN ECD power and the asymmetry coefficient (AC) were negatively correlated with the positive scores from Positive and Negative Syndrome Scale (PANSS) ( r=−0.673, p=0.008), especially with the hallucinatory behavior subscale ( r=−0.677, p=0.008). These findings support the deficits in preattentive automatic processing of auditory stimuli, especially in the left hemisphere, and indicate the correlation between positive symptoms, especially auditory hallucination, and left temporal lobe dysfunction in schizophrenia.

Morphometric and neuropsychologic studies in children with arachnoid cysts

Temporal lobe arachnoid cysts are common findings during brain imaging. Debate exists regarding whether they result from temporal lobe agenesis or are a malformation of the arachnoid matter. We measured temporal lobe volumes in five children with left middle cranial fossa arachnoid cysts using morphometric analysis of magnetic resonance imaging scans. Three patients had neuropsychologic testing, and two patients had positron emission tomography scanning. All patients had significantly smaller left temporal lobes compared with the right side. On neuropsychologic testing two patients had cognitive deficits suggestive of left temporal lobe dysfunction. Temporal lobes adjacent to arachnoid cysts are smaller and less metabolically active when compared with the temporal regions on the opposite side. Patients with middle cranial fossa arachnoid cysts should undergo careful assessment of temporal lobe structure and function before any therapeutic intervention.

Processing of rapid auditory information in epileptic patients with left temporal lobe damage

The role of the temporal lobes in processing time-related (temporal) information was tested in a task of anisochrony (or irregularity) discrimination assessing the temporal processing of sequential auditory information according to different presentation rates or tempos (between 80 and 1000 ms inter-onset intervals, IOI). Epileptic patients with either left (LHA, n=8) or right (RHA, n=10) hippocampal atrophy participated in this study as well as six normal control subjects (NC). For all the subjects, an effect of tempo was obtained, thresholds deteriorating for the 80 ms IOI as compared to longer IOI (the latter conforming to Weber's law). Furthermore, there was a specific impairment of rapid anisochrony discrimination (80 ms IOI) for patients with LHA as compared to patients with a RHA and NC, whereas no significant deficit was observed in these patients for longer IOI. These findings are in agreement with studies carried out in patients with left-hemisphere damage associated with massive language disorders and suggest the specialisation of left medial temporal lobe structures in processing rapid sequential auditory information. However, these results might also be explained by an auditory memory deficit in the presence of left temporal lobe dysfunction, as opposed to a specific impairment of fast sequential temporal processing.

Brain event-related potentials (ERPs) in schizophrenia during a word recognition memory task

Impairments of recognition memory for words and attenuation of the ERP ‘old–new’ effect have been found in patients with left medial temporal lobe damage. If left temporal lobe dysfunction in schizophrenia involves medial structures (e.g. hippocampus), then schizophrenic patients might show similar abnormalities of verbal recognition memory. This study recorded ERPs from 30 electrode sites while subjects were engaged in a continuous word recognition memory task. Results are reported for 24 patients having a diagnosis of schizophrenia ( n=16) or schizoaffective disorder ( n=8) and 19 age-matched healthy controls. Both patients and controls showed the expected ‘old–new’ effect, with greater late positivity to correctly recognized old words at posterior sites, and there was also no significant difference between groups in P3 amplitude. However, accuracy of word recognition memory was poorer in patients than controls, and patients showed markedly smaller N2 amplitude. Reduced amplitudes of N2 and N2–P3 were associated with poorer performance, with highest correlations over the left inferior parietal (N2) and left medial parietal (N2–P3) region. Moreover, patients failed to show significantly greater left than right hemisphere amplitude of N2–P3 at posterior sites, which was seen for healthy controls. These findings suggest that impaired word recognition in schizophrenia may arise from a left lateralized deficit at an early stage of processing, beginning at 200–300 ms after word onset.

The relationship between auditory ERP and neuropsychological assessments in schizophrenia

To clarify the cognitive significance of event-related potential (ERP) abnormalities in schizophrenia, we examined the relationships of amplitudes and latencies of ERP components with performance on neuropsychological tests in schizophrenic patients. Twenty patients underwent the Trail Making B Test (TM-B), which is sensitive to frontal lobe dysfunction, and the logical memory, verbal paired-association, and visual reproduction subtests of the Wechsler Memory Scale (WMS), which are sensitive to temporal lobe dysfunctions, and ERP recordings during performance of an oddball auditory discrimination task. Pearson product–moment correlations indicated that an increased P200 amplitude was correlated with poor performance on the TM-B, whereas a decreased P300 amplitude was correlated with poor performance on the verbal paired-association subtest of the WMS. These findings suggest that a P200 abnormality represents the frontal lobe dysfunction, and a P300 abnormality represents the left temporal lobe dysfunction in schizophrenia.

Left temporal lobe dysfunction in schizophrenia: event-related potential and behavioral evidence from phonetic and tonal dichotic listening tasks.

Asymmetric reduction of the P3 event-related potential (ERP) has provided evidence of left temporal lobe dysfunction in schizophrenia. Prior studies have been limited by reliance on simple target detection (oddball) tasks with pure tones. This study investigated the time course and topography of ERPs to binaural syllables or complex tones in dichotic listening tasks. Event-related potentials of 26 patients meeting criteria for schizophrenia (n = 19) or schizoaffective disorder (n = 7) and 26 healthy controls were recorded from 30 scalp electrodes during 2 dichotic tasks in which different syllables or complex tones were simultaneously presented to each ear. A principal components analysis was used to derive factor scores corresponding to overlapping components in ERP waveforms--N1, N2, P3, and a late-positive potential. Healthy controls showed a right ear advantage for perceiving dichotic syllables, which was associated with greater N2 amplitude at left than right temporoparietal sites. Patients with schizophrenia did not show either this perceptual or N2 asymmetry. Patients also had smaller late-positive potential amplitude when compared with controls for both syllables and complex tones, with greatest decrement over left temporal sites. A right ear advantage in healthy adults for perceiving consonant-vowels was associated with a left-lateralized ERP component peaking at 200 milliseconds after syllable onset (N2). Patients with schizophrenia failed to show either of these task-dependent asymmetries, which may indicate a dysfunction of left temporal regions involved in phonetic classification. A task-independent asymmetric reduction of a later positive potential in patients with schizophrenia resembled left temporal P3 reductions reported for auditory oddball tasks.

Ephemeral New Traces and Evaporated Remote Engrams: A Form of Neocortical Temporal Lobe Amnesia? A Preliminary Case Report

We report the case of a patient (GB) with a 2-year history of memory disturbances characterized by forgetting of both recently learned traces and remote information acquired decades before. Forgotten contents involved the episodic aspects of autobiographical and media-mediated information. Moreover, a mild anterograde verbal learning defect was evident. General cognition was normal. In the last months of our observation, GB developed partial complex epilepsy with EEG evidence of a left temporal anterior focus. He never experienced acute transient amnesic episodes. MRI showed normal and symmetrical temporomedial aspects, and a slight ventricular asymmetry with a greater extension of the left ventricle. No brain atrophy was apparent. It is speculated that GB's memory loss is the consequence of a neocortical left temporal lobe dysfunction due to a still obscure underlying degenerative process which produces, as its neurological counterpart, not atrophy, but epilepsy. Temporal epilepsy is cautiously rejected as a crucial determinant of GB's amnesia.

First-episode schizophrenic psychosis differs from first-episode affective psychosis and controls in P300 amplitude over left temporal lobe.

Schizophrenia is associated with central (sagittal) midline reductions of the P300 cognitive event-related potential and topographic asymmetry of P300, with reduced left temporal voltage. This P300 asymmetry is, in turn, linked to tissue volume asymmetry in the posterior superior temporal gyrus. However, it is unknown whether P300 asymmetry is specific to schizophrenia and whether central and lateral P300 abnormalities are due to chronic morbidity, neuroleptic medication, and/or hospitalization, or whether they are present at the onset of illness. P300 was recorded in first-episode schizophrenia, first-episode affective psychosis, and control subjects (n = 14 per group). Subjects silently counted rare (15%) target tones (1.5 kHz) among trains of standard tones (1.0 kHz). Averages were constructed from brain responses to target tones. Peak amplitude of P300 and integrated voltage over 300 to 400 milliseconds were significantly different between first-episode schizophrenics and controls over the posterior sagittal midline of the head. First-episode schizophrenics displayed smaller amplitudes over the left temporal lobe than first-episode affective psychotics and controls, but the groups showed no differences over the right temporal lobe. Left-sided P300 abnormality in first-episode schizophrenia relative to first-episode affective psychosis and controls suggests that P300 asymmetry is specific to schizophrenic psychosis and present at initial hospitalization. This P300 asymmetry suggests left temporal lobe dysfunction at the onset of schizophrenia.

Left temporal lobe dysfunction: Utility of the Russell WAIS index in an epilepsy population

Left temporal lobe dysfunction: Utility of the Russell WAIS index in an epilepsy population

Left temporal lobe dysfunction: Utility of the Russell WAIS index in an epilepsy population

Left temporal lobe dysfunction: Utility of the Russell WAIS index in an epilepsy population

Psychogenic mechanisms of prolonged autobiographical retrograde amnesia

Abstract Much of the previous literature on retrograde amnesia (RA) has emphasized either psychogenic or neurologic explanations. Two cases of persistent RA for autobiographical material after cerebral dysfunction are described, including 9-year follow-up data. Each case had both psychogenic features and evidence of left temporal lobe dysfunction, although the latter was transient in one case. For these cases there was no likely neurologic explanation for RA, and the data suggested psychogenic etiology. Distinguishing features of neurologic and psychogenic causes of RA are summarized. It is recommended that researchers investigating presumptive cases of RA of neurologic origin rule out psychogenic explanations through hypnosis or sodium amytal interviews and careful review of history.

Cerebral blood flow in schizophrenia: Effects of memory processing on regional activation

Regional cerebral blood flow (rCBF) was measured with the 133Xenon clearance technique and a high resolution (254 detectors) scanner during the performance of a verbal and a facial memory task in 18 patients with schizophrenia and 18 sociodemographically matched controls. Patients and controls had comparable resting rCBF, but differed in global and hemispheric rCBF changes induced by the memory tasks. Patients had less global increase, which was relatively higher in the left hemisphere, and this was more pronounced for the verbal task. Although controls showed appropriate laterality changes (L > R for verbal and R > L for facial memory) in the midtemporal region, patients failed to show such a focal pattern. They did not show appropriate laterality change in the midtemporal region, but instead showed such changes in other regions. Patients showed greatest impairment in specificity of verbal recognition performance, and this correlated with severity of hallucinations and delusions. This supports a model of left temporal lobe dysfunction in schizophrenia.

Wisconsin card sorting performance: Effects of age of onset of damage and laterality of dysfunction

Wisconsin Card Sorting Performance was examined in patients with complex partial seizures of left (n = 35) or right (n = 42) temporal-lobe origin. Our findings suggest that poor performance, in the form of perseveration, occurs in the context of nonfrontal dysfunction and depends not only on the laterality of the epileptogenic disturbance but also on the age of onset of the damage. The ability to shift set is most impaired by left temporal-lobe dysfunction, but only when the damage occurs very early in life. Left temporal-lobe dysfunction after one year of age leaves sorting behavior relatively intact. Perseveration may also occur in the context of right temporal-lobe dysfunction, regardless of the age of onset of the damage, although the deficit tends to be less marked. Finally, the occurrence of the deficit does not depend upon the status of the cerebral speech pattern or general intellectual level.