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Supplementary CT temporal lobe cuts confer no worthwhile benefit.

The value of angled temporal lobe cuts as a supplement to conventional head computed tomography (CT) has been assessed by comparing the diagnostic yield of standard axial and specific temporal lobe images (TLCT) in 62 patients with temporal lobe epilepsy and 87 with Alzheimer-type senile dementia. Fewer than one patient in six had structural abnormality in the temporal lobe most readily demonstrated by axial CT. Five patients with epilepsy and ten with dementia had changes demonstrated only by TLCT, reported on by one or other of a pair of observers. However such changes were of dubious clinical relevance, or arose as a result of artefact. In one patient with epilepsy and underlying neoplasm, axial CT was positive and TLCT false-negative. The routine addition of temporal lobe cuts to a conventional axial examination confers no added benefit to justify the prolonged examination time and increased radiation dose to the lens of the eye.

Alzheimer Disease↗

Cardiac asystole during a temporal lobe seizure.

The association between temporal lobe seizures and cardiac arrhythmias has been anecdotally reported in the literature. Ictal bradycardia and cardiac asystole are rare, and maybe underestimated. The physiological mechanism is poorly understood. We report a patient with left temporal lobe seizures who developed ictal bradycardia and cardiac asystole during a complex partial seizure and required a subsequent placement of a pacemaker.

Adult↗

Prognostic implication of contralateral secondary electrographic seizures in temporal lobe epilepsy.

PURPOSE: Interhemispheric propagation of seizures in temporal lobe epilepsy is frequently noted during intracranial EEG monitoring. We hypothesized that a distinct secondary electrographic seizure (DSES) in the temporal lobe contralateral to primary seizure onset may be an unfavorable prognostic indicator. METHODS: We reviewed intracranial depth electrode EEG recordings, 1-year outcome, and medical records of 51 patients (M 29, F 22: age 15-64 years) who underwent anterior temporal lobectomy during 1988-96. We defined DSES as a seizure that spread to the contralateral temporal lobe and produced distinct contralateral EEG features. The distinct feature was focal involvement of one or two electrode contacts at onset, which starts and evolves independently from the ipsilateral temporal lobe. We considered DSES as the predominant seizure pattern when it occurred in more than one half of the patients' recorded seizures. RESULTS: Only nine of 19 (47%) patients with predominant DSES had a 1-year seizure-free outcome, whereas 27 of 32 (84%) patients without predominant DSES had a 1-year seizure-free outcome (p < 0.01). Bitemporal independent seizures were more common in patients with predominant DSES (9/19 versus 0/32; p < 0.001). CONCLUSION: Our results suggest that distinct contralateral secondary electrographic seizure is a predictor of unfavorable outcome and is also more likely to be associated with bitemporal seizures.

Adolescent↗

Interictal mood and personality disorders in temporal lobe epilepsy and juvenile myoclonic epilepsy.

BACKGROUND: Mood disorders have been described as the commonest psychiatric disorders in patients with temporal lobe epilepsy. Secondary depression in temporal lobe epilepsy could be interpreted either as an adjustment reaction to a chronic disease or as a limbic dysfunction. To clarify this issue, a controlled study of psychiatric disorders was conducted in different forms of epileptic and non-epileptic chronic conditions. METHODS: Twenty outpatients with temporal lobe epilepsy, 18 outpatients with juvenile myoclonic epilepsy--a primary generalised seizure disorder--20 matched type I diabetic patients, and 20 matched normal controls were assessed by a structured interview (SADS) and by self rating scales (Beck depression inventory (BDI) and the state and trait anxiety scales STAIX1 and STAIX2). RESULTS: Sixteen (80%) patients with temporal lobe epilepsy fulfilled the criteria for a psychiatric diagnosis at the SADS interview with a significantly higher frequency than patients with juvenile myoclonic epilepsy (22%) and diabetic patients (10%) (P < 0.0001). The most frequent disorder in temporal lobe epilepsy was a mood disorder: 11 (55%) patients with temporal lobe epilepsy had depression compared with three patients with juvenile myoclonic epilepsy and two diabetic patients (P < 0.001). Eight patients with temporal lobe epilepsy with an affective disorder also had a comorbid personality or anxiety disorder. Patients with temporal lobe epilepsy scored significantly higher on BDI, STAIX1, and STAIX2 than the three control groups (P < 0.001, P < 0.01, P < 0.001). CONCLUSIONS: Patients with temporal lobe epilepsy have a higher incidence of affective and personality disorders, often in comorbidity, than patients with juvenile myoclonic epilepsy and diabetic patients suggesting that these psychiatric disorders are not an adjustment reaction to a chronic disease but rather reflect a limbic dysfunction.

Adult↗

Correlation of apparent diffusion coefficient with neuropsychological testing in temporal lobe epilepsy.

BACKGROUND AND PURPOSE: Patients with nonlesional temporal lobe epilepsy have long been known to have abnormalities of memory. Recently, these patients have been shown to have increased diffusivity in the hippocampus. We hypothesized that in these patients, a negative correlation would exist between diffusivity measures of the mesial temporal lobe and performance on neuropsychological tests. METHODS: Twenty presurgical patients with temporal lobe epilepsy and 20 age- and sex-matched healthy controls underwent MR imaging of the brain. Apparent diffusion coefficient region of interest measures were taken in both hippocampi and parahippocampal gyri by 2 independent observers. Mean whole brain diffusivity was calculated. All patients completed neuropsychological testing. Electroencephalogram and pathology results were collected. Patients and controls were compared with respect to each apparent diffusion coefficient measure. In patients, apparent diffusion coefficients ipsilateral and contralateral to the seizure focus were compared. Associations were assessed between diffusivity measures and neuropsychological scores. RESULTS: Eleven patients had right-sided seizure foci and 9 had left-sided seizure foci. Patients demonstrated higher apparent diffusion coefficient values than controls over the whole brain, in the hippocampi, and in the parahippocampal gyri (P < .05). Patients demonstrated higher apparent diffusion coefficient within the ipsilateral hippocampus (1.19 +/- 0.22 x 10(-3) s/mm2) and parahippocampal gyrus (1.02 +/- 0.12 x 10(-3) s/mm2) compared with the contralateral side (1.02 +/- 0.16 x 10(-3) s/mm2 and 0.96 +/- 0.09 x 10(-3) s/mm2, respectively) (P < .05). Negative correlations were seen between hippocampal apparent diffusion coefficients and multiple memory tests (P < .05). CONCLUSION: Quantitative diffusion measurements in the hippocampus correlate with memory dysfunction in patients with temporal lobe epilepsy.

Adult↗

Relational verbal memory processing in patients with temporal lobe epilepsy.

Patients with left temporal lobe epilepsy (LTLE) have been shown to demonstrate impaired categorization in semantic memory tasks leaving open the question whether this is due to problems with active categorization or to problems with consolidation/retrieval of relations. 35 patients with left or right temporal lobe epilepsy (LTLE, RTLE) and 20 healthy controls performed three verbal learning and memory tests differing in the relational distance between the items to be learned (unrelated, low associative, high associative). In order to separate the memory component in relational memory processing, we avoided problems in active categorization and perception of semantic relations by presenting category members already clustered in the order of category membership, and by checking whether the patients had actually noticed the categories. In controls and in patients with RTLE, both semantic conditions significantly improved the test performance. LTLE-patients showed the worst test performance independent of the test condition. Their performance improved under the high associative condition, but they did not at all profit from the low associative condition. Although the semantic tasks had no demand on active clustering and although all LTLE-patients noticed the relational properties very well, they could not make use of the offered clusters. They demonstrated significantly more "item specific" than "relational" encoding than the other groups. This was pronounced in the low associative condition but became evident also in the high associative condition. In contrast to the other groups, the order in recall (clustering) deteriorated with passing time in LTLE-patients. In conclusion the data provide evidence of impaired semantic relational processing in LTLE. The impairment depends on the relational properties of the material to be learned, in that it increases with the relational distance between the memory contents. Because the tasks did not demand active clustering, we can attribute this impairment to deficits in relational encoding/retrieval which would be consistent with current opinions of the role of temporolimbic structures in relational memory processing.

Adult↗

Temporal and spatial context memory in patients with focal frontal, temporal lobe, and diencephalic lesions.

Patients with focal frontal, temporal lobe, or diencephalic lesions were investigated on measures of temporal (recency) and spatial (position) context memory, after manipulating exposure times to match recognition memory for targets (pictorial stimuli) as closely as possible. Patients with diencephalic lesions from an alcoholic Korsakoff syndrome showed significant impairment on the temporal context (recency) task, as did patients with frontal lesions penetrating the dorsolateral frontal cortex, according to MRI (and PET) evidence. Patients with temporal lobe lesions showed only a moderate (non-significant) impairment on this task, and patients with medial frontal lesions, or large frontal lesions not penetrating the dorsolateral cortical margins, performed as well as healthy controls at this task. On the spatial context memory task, patients with lesions in the temporal lobes showed significant impairment, and patients with right temporal lesions performed significantly worse than patients with left temporal lesions. Patients with diencephalic lesions showed only a modest (non-significant) impairment on this task, and the frontal lobe group performed normally. When a group of patients with temporal lobe lesions resulting from herpes encephalitis were examined separately, an identical pattern of results was obtained, the herpes group being significantly impaired on spatial memory and showing a trend towards impairment for temporal context memory. There were strong correlations between anterograde memory quotients and context memory performance (despite the use of an exposure time titration procedure) and a weak association in the frontal group with one frontal/executive task [corrected] (card-sorting perservations). It is predicted that correlations between temporal context memory and frontal/executive tasks will be greater in samples of patients all of whom have frontal lesions invading the dorsolateral cortical margin.

Adult↗

Clinical features and EEG findings differentiating mesial from neocortical temporal lobe epilepsy.

We evaluated whether mesial temporal lobe epilepsy (MTE) and neocortical temporal lobe epilepsy (NTE) can be distinguished on electroclinical grounds. One hundred and twenty-two consecutive MTE (n = 86) and NTE (n = 36) patients were included in this prospective study. All patients underwent prolonged EEG-video monitoring and high resolution magnetic-resonance imaging (MRI). MTE was defined as epilepsy with purely mesial temporal lesion in the absence of extramesial temporal pathology, based on pre-operative MRI or post-operative histology. NTE was defined as neocortical temporal MRI lesions, depth recorded neocortical temporal seizure onset and lack of mesial temporal lesions on MRI or histology. One thousand two hundred and fourty-nine epileptic seizures were analyzed. Congenital malformation (NTE 19% versus MTE 3%, P < 0.01), nonspecific auras (NTE 25% versus MTE 8%, P < 0.001) and early clonic activity following automatisms (NTE 22% versus MTE 8%, P < 0.03) were more frequent in NTE. In contrast, a history of febrile seizures (MTE 29% versus NTE 3%, P < 0,001), abdominal auras (MTE 62% versus NTE 33%, P < 0.005) and contralateral hand dystonia (MTE 43% versus NTE 22%, P < 0.03) were more often documented in MTE. Interictal epileptiform discharges in MTE occurred predominantly (> 67%) over the ipsilateral mesial temporal regions (MTE 65% versus NTE 33%, P < 0.001). No MTE patient had lateral neocortical temporal spike predominance (NTE 22%, P < 0.001). Multiple logistic regression revealed that a history of febrile seizures, abdominal auras, contralateral dystonic posturing and predominance of ipsilateral mesial temporal spikes point to MTE, with an accuracy of 73% (PPV 81%, NPV 70%). Analyzing clinical and EEG features, particularly the distribution of interictal epileptiform discharges, helps to differentiate between MTE and NTE.

Adult↗

Topographical disorientation following unilateral temporal lobe lesions in humans.

Studies of the non-human temporal lobe, particularly the hippocampus, confirm its significant role in learning and memory, particularly allocentric spatial mapping of the environment. The role of the human temporal lobes in topographical orientation was investigated by examining the formation of representations of a large-scale real-world environment after unilateral left and right temporal lobe surgery. Patients and normal control subjects viewed videotape presentations of overlapping routes through a novel urban area. Topographical orientation was then assessed across a range of parameters. Right temporal lobe lesions alone gave rise to deficits in making proximity judgements. However, on all other topographical orientation tasks both right and left temporal lobe lesion groups were impaired relative to the normal control group, but the two patient groups did not differ significantly from each other. These findings suggest that such is the nature of remembering and way-finding in the environment that the integrity of both human temporal lobes is required.

Adult↗

Significance of preserving the vein of Labbé in epilepsy surgery involving temporal lobe resection.

OBJECT: Preservation of the vein of Labbé is recommended to prevent temporal lobe infarction after skull base surgery. However, the importance of preserving the vein in epilepsy surgery involving resection of the temporal lobe is unclear. METHODS: Retrospective analysis was performed in 47 cases, in which patients underwent temporal lobe resection, out of 148 cases in which patients underwent surgery for intractable seizures over a 5-year period. Standard temporal lobe resection anterior to the vein of Labbé was performed in 11 patients. In 24 patients, the temporal lobe resection extended posterior to the vein of Labbé; the vein was preserved in eight patients, who underwent surgery prior to 2002, and resected in the other 16 patients, who underwent surgery after 2002. Twelve patients underwent a temporoparietooccipital resection. There was no significant difference in the pattern of venous anatomy (based on analysis of the relative size of veins [chi-square test, p = 0.1] and the number of superficial veins draining the temporal lobe [p = 1]) in patients in whom the vein was resected compared with those in whom it was preserved. No patient experienced postoperative infarction. CONCLUSIONS: The authors conclude that the vein of Labbé may be safely resected in epilepsy surgery involving temporal lobe resection. The decision whether to resect the vein need not be based on the surface venous drainage pattern or number of veins draining the temporal lobe.

Adolescent↗

Hyperphagia and obesity in female rats with temporal lobe lesions.

Damage to the temporal lobes in cats, dogs, and primates has long been known to result in hyperphagia and obesity, but research into the role of this area of the brain in feeding behavior has largely been neglected because of an inability to produce similar results in rats. The present study reports hyperphagia and obesity in female rats with small electrolytic lesions centered in the posterodorsal amygdala. Daily food intake more than doubled in the first few days after surgery and mean weight gain was more than four times that observed in animals with sham lesions during the first 26 days. The rats with lesions were not hyperresponsive to a switch in diets (lab chow to high-fat, and back). In all animals that gained abnormal amounts of weight, the posterior extent of the lesions extended through the amygdalohippocampal area into the ventral hippocampal formation. The results suggest that the temporal lobe is an important extrahypothalamic site for the regulation of food intake in rodents.

Animals↗

Increased expression of phosphate-activated glutaminase in hippocampal neurons in human mesial temporal lobe epilepsy.

Patients with mesial temporal lobe epilepsy (MTLE) have increased basal concentrations of extracellular glutamate in the epileptogenic versus the non-epileptogenic hippocampus. Such elevated glutamate levels have been proposed to underlie the initiation and maintenance of recurrent seizures, and a key question is what causes the elevation of glutamate in MTLE. Here, we explore the possibility that neurons in the hippocampal formation contain higher levels of the glutamate synthesizing enzyme phosphate-activated glutaminase (PAG) in patients with MTLE versus patients with other forms of temporal lobe epilepsy (non-MTLE). Increased PAG immunoreactivity was recorded in subpopulations of surviving neurons in the MTLE hippocampal formation, particularly in CA1 and CA3 and in the polymorphic layer of the dentate gyrus. Immunogold analysis revealed that PAG was concentrated in mitochondria. Double-labeling experiments indicated a positive correlation between the mitochondrial contents of PAG protein and glutamate, as well as between PAG enzyme activity and PAG protein as determined by Western blots. These data suggest that the antibodies recognize an enzymatically active pool of PAG. Western blots and enzyme activity assays of hippocampal homogenates revealed no change in PAG between MTLE and non-MTLE, despite a greatly (>50%) reduced number of neurons in the MTLE hippocampal formation compared to non-MTLE. Thus, the MTLE hippocampal formation contains an increased concentration and activity of PAG per neuron compared to non-MTLE. This increase suggests an enhanced capacity for glutamate synthesis-a finding that might contribute to the disrupted glutamate homeostasis in MTLE.

Adolescent↗

Hippocampal volumetric and morphometric studies in frontal and temporal lobe epilepsy.

The most common temporal lobe pathology is Ammons Horn sclerosis (AHS), and several different imaging techniques have been utilized to detect this with varying success. We describe the clinical application of magnetic resonance imaging (MRI) using a three-dimensional volume technique which allows total hippocampal volume to be measured and symmetry evaluated. Hippocampal surface area was calculated in sequential 1.5 mm thick contiguous images, using a GE IC workstation. Total volumes and surface areas were calculated. The cross-sectional surface area at 1.5 mm intervals was displayed graphically, permitting morphometric analysis of the hippocampus throughout its length. Focal atrophy within any part of the hippocampal formation (HF) and its extent could thus be assessed. Patients with well-lateralized temporal lobe epilepsy (TLE) (n = 20) and well-defined frontal lobe epilepsy (FLE) (n = 20) were studied, and volumes compared with normal values derived from 10 neurologically normal controls. Asymmetric hippocampal volume loss was demonstrated in all 20 patients with clinically typed TLE, but not in normal controls or patients with FLE. Volume loss distribution was anterior in 12 patients, posterior in one patient and widespread in seven patients. Secondarily generalized seizures were strongly associated with widespread loss. This method of surface area and volumetric analysis of the hippocampus in TLE can demonstrate asymmetry and focal involvement, and help distinguish between hippocampal and frontal pathologies.

Adult↗

Clinical and EEG analysis of mesial and lateral temporal lobe seizures.

The analysis of the temporal lobe seizures through video-EEG systems shows that they often consist of a sequence of clinical and EEG features which may suggest the localization and the lateralization of the epileptogenic lobe. We analyzed clinical and EEG features of 50 temporal lobe seizures which were separated in group 1 with 25 patients (related to mesial temporal sclerosis) and group 2 with 25 patients (other neocortical temporal lesions). Among the auras, the epigastric type was the most frequent and predominated in group 1. There were differences between the two groups, considering dystonic and tonic posturing and versive head and eye movements. Dystonic posturing was always contralateral to the ictal onset and was considered the most useful lateralizing clinical feature. Ictal speech, spitting and blinking automatisms, prolonged disorientation for place and a greatest percentage of postictal language preservation occurred in right temporal seizures. Postictal aphasia and global disorientation predominated in left temporal seizures. EEG was important for lateralizing the epileptogenic lobe, specially considering rhythmic ictal activity and postictal findings.

Dystonia↗

[Mesial temporal lobe anatomy and its relationships with surrounding structures].

OBJECTIVE: To explore the anatomy of mesial temporal lobe and the relationships between the mesial temporal lobe and its surrounding structures. METHODS: Twenty formalin-fixed adult cadaveric heads after perfusion of the arteries and veins with colored latex were studied under microscope, and photographs were taken. RESULTS: The hippocampus, fimbria, amygdala and choroidal fissure constituting the mesial temporal lobe were intraventricular structures, and uncus, parahippocampal gyrus, and dentate gyrus were extraventricular structures. The apex of the uncus pointed to the oculomotor nerve and posterior communicating artery. The anterior segment faced the cistern of Sylvius, ICA and MCA. The posterior segment faced the Crus cerebri. The uncus was related medially to the posterior cerebral artery, anterior choroidal artery, and optic tract. CONCLUSION: The structures of the mesial temporal lobe are complicated, so understanding of the mesial temporal lobe anatomy and the relationships between the mesial temporal lobe and its surrounding structures is conducive to the microsurgical operations of the mesial temporal lobe lesions.

Amygdala↗

Auditory/visual duration bisection in patients with left or right medial-temporal lobe resection.

Patients with unilateral (left or right) medial temporal lobe lesions and normal control (NC) volunteers participated in two experiments, both using a duration bisection procedure. Experiment 1 assessed discrimination of auditory and visual signal durations ranging from 2 to 8 s, in the same test session. Patients and NC participants judged auditory signals as longer than equivalent duration visual signals. The difference between auditory and visual time discrimination was equivalent for the three groups, suggesting that a unilateral temporal lobe resection does not modulate the modality effect. To document interval-timing abilities after temporal lobe resection for different duration ranges, Experiment 2 investigated the discrimination of brief, 50-200 ms, auditory durations in the same patients. Overall, patients with right temporal lobe resection were found to have more variable duration judgments across both signal modality and duration range. These findings suggest the involvement of the right temporal lobe at the level of the decision process in temporal discriminations.

Acoustic Stimulation↗

Intractable complex partial seizures associated with occult temporal lobe encephalocele and meningoangiomatosis: a case report.

Occult congenital temporal lobe encephalocele has rarely been reported in association with medically intractable complex partial seizures. The four previously reported cases were unsuspected preoperatively. We present the case of an 18-year-old woman with intractable complex partial seizures since age 13. Seizure onset was electrically localized to the right temporal lobe. Preoperative neuroimaging studies revealed a middle fossa defect and inferior herniation of the right temporal lobe. Pathologic examination of the resected encephalocele revealed prominent features of meningoangiomatosis. We believe this to be the first case of temporal lobe encephalocele and epilepsy to be diagnosed preoperatively, and the first case also to be associated with meningoangiomatosis. The relevant literature on meningoangiomatosis and on temporal lobe encephalocele as a cause of epilepsy is reviewed.

Adolescent↗

[Diagnosis and surgical treatment of temporal lobe epilepsy].

OBJECTIVE: To discuss the diagnosis and surgical treatment of temporal lobe epilepsy. METHODS: From 1995 to 1998, 30 patients with intractable mesial temporal lobe epilepsy were identified by EEG and MR. Among them, 15 patients underwent anterior temporal lobectomy, while another 15 patients accepted selective amygdalahippocampectomy. The results of operation and follow-up were analyzed. RESULTS: As to seizure outcome, all patients were benefited from surgery. Surgical result was satisfactory in 18 patients, notable in 11, and good in 1. There was no complication. CONCLUSIONS: MR is beneficial for the localization of epileptic foci. Operation is an effective way for the treatment of temporal lobe epilepsy. Selective amygdalohippocampus is the first choice for medial temporal lobe epilepsy. Transzygmatic-temporal lobe base approach improves the safety of operation.

Adolescent↗