Biomedical subjects

A Bernasconi

Publications and source records attributed to A Bernasconi.

At least 19 recordsLinked to original sources

PubMed2006

Segmentation of focal cortical dysplasia lesions on MRI using level set evolution.

Focal cortical dysplasia (FCD) is the most frequent malformation of cortical development in patients with medically intractable epilepsy. On MRI, FCD lesions are not easily differentiable from the normal cortex and defining their spatial extent is challenging. In this paper, we introduce a method to segment FCD lesions on T1-weighted MRI. It relies on two successive three-dimensional deformable models, whose evolutions are based on the level set framework. The first deformable model is driven by probability maps obtained from three MRI features: cortical thickness, relative intensity and gradient. These features correspond to the visual characteristics of FCD and allow discriminating lesions and normal tissues. In a second stage, the previous result is expanded towards the underlying and overlying cortical boundaries, throughout the whole cortical section. The method was quantitatively evaluated by comparison with manually traced labels in 18 patients with FCD. The automated segmentations achieved a strong agreement with the manuals labels, demonstrating the applicability of the method to assist the delineation of FCD lesions on MRI. This new approach may become a useful tool for the presurgical evaluation of patients with intractable epilepsy related to cortical dysplasia.

Adult↗

PubMed2006

Hearts with concordant ventriculoarterial connections but parallel arterial trunks.

OBJECTIVES: To determine the characteristic morphological features of hearts with concordant ventriculoarterial connections and parallel arterial trunks, and to provide unequivocally a method to describe their anatomy. DESIGN, METHODS AND PATIENTS: The entire cardiac database and cardiac pathological archive at the Hospital for Sick Children, Toronto, Ontario, Canada, was interrogated to identify all patients with concordant ventriculoarterial connections and parallel arterial trunks. The clinical records, autopsy reports and actual cardiac specimens of those who underwent autopsy, were reviewed. RESULTS: 8 cases meeting our criteria were identified. The infundibular anatomy was variable, including four hearts with bilateral infundibulums, three with subpulmonary infundibulums and one with bilaterally absent infundibulums. Considerable variability was also found in the type of atrial arrangement, along with the morphology of the atrioventricular junctions. The most common findings were the usual atrial arrangement (n = 5), left juxtaposition of the right atrial appendages (n = 3), an atrial septal defect (n = 6), univentricular atrioventricular connection (n = 5), ventricular septal defect (n = 8) and pulmonary obstruction (n = 4). In addition, five specimens had either a single coronary artery or two coronary arteries arising from the anticipated right coronary aortic sinus. CONCLUSIONS: Concordant ventriculoarterial connections with parallel arterial trunks can be found in a variety of segmental combinations. An accurate diagnosis of these rare hearts can be achieved by detailed analysis of not only the ventriculoarterial connections but also the infundibular anatomy and the spatial relationship of the arterial trunks. Particular attention to the coronary arteries is warranted.

Aorta↗

PubMed2006

Patterns of hippocampal abnormalities in malformations of cortical development.

OBJECTIVE: To assess whether different types of malformation of cortical development (MCD) are associated with specific patterns of hippocampal abnormalities. METHODS: A total of 122 consecutive patients with MRI diagnosis of MCD (53 males, age range 1-58 years) were included in the study. Hippocampal measurements were made on 1-3 mm coronal T1-weighted MRIs and compared with MRIs of normal controls. RESULTS: A total of 39 patients had focal cortical dysplasia, 5 had hemimegalencephaly, 5 had lissencephaly-agyria-pachygyria, 11 had SLH, 11 had PNH, 12 had bilateral contiguous PNH, 5 had schizencephaly, and 34 had polymicrogyria. The frequency of hippocampal abnormalities in these patients with MCD was 29.5%. A small hippocampus was present in all types of MCD. Only patients with lissencephaly and SLH had an enlarged hippocampus. Abnormalities in hippocampal rotation and shape were present in all types of MCD; however, these predominated in PNH. None of the patients with lissencephaly-agyria-pachygyria or SLH had hyperintense signal on T2 or FLAIR images or abnormal hippocampal internal architecture. CONCLUSION: A small hippocampus was present in all types of MCD; however, the classic MRI characteristics of hippocampal sclerosis were often lacking. Abnormal enlargement of the hippocampus was associated with only diffuse MCD due to abnormal neuronal migration (lissencephaly-agyria-pachygyria and SLH).

Adolescent↗

PubMed2005

Preictal headache in partial epilepsy.

The authors studied clinical characteristics in 11 patients with intractable focal epilepsy and preictal headache (PIHA) using a standardized interview. Headache was frontotemporal, ipsilateral to the focus, in nine patients with temporal lobe epilepsy (TLE) and contralateral in one with TLE and in one with frontal seizures. Migrainous features were found in four. After surgery, all seven seizure-free patients and two with rare seizures were free of PIHA. It may be a useful lateralizing sign in patients with TLE.

Adolescent↗

PubMed2005

Thirteen years of culture-positive M. bovis-BCG infection in an IL-12Rbeta1 deficient patient: treatment and outcome.

Patients with mutations in the IFNgamma/IL-12 pathway show an exquisite susceptibility to mycobacterial diseases. An IL-12Rbeta1 deficient patient with impaired intestinal absorption suffered from a 13 year culture-positive Mycobacterium bovis-BCG infection with acquired multidrug resistance. A combined parenteral and enteral anti-mycobacterial treatment, including recombinant IFNgamma, helped to clear his infection.

Adolescent↗

PubMed2005

MR-based neurological disease classification methodology: application to lateralization of seizure focus in temporal lobe epilepsy.

Classification approaches for neurological diseases tend to concentrate on specific structures such as the hippocampus (HC). The hypothesis for the novel methodology presented in this work is that pathologies will impact large tissue areas with detectable variations of T1-weighted MR signal intensity and registration metrics. The technique is applied to lateralization of seizure focus in 127 patients with intractable temporal lobe epilepsy (TLE), in which the site of seizure onset was determined by comprehensive evaluation (69 with left MTL seizure focus (SF) (group "L") and 58 with right SF (group "R")). The method analyses large, non-specific Volumes of Interest (VOI) centered on the left and right medial temporal lobes (MTL) (55 x 82 x 80 voxels) in pre-processed scans aligned in stereotaxic space. Extracted VOIs are linearly and nonlinearly registered to a reference target image. Principal Components Analyses of (i) the normalized intensity and (ii) the trace, a measure of local volume change, are used to generate a multidimensional reference space from a set of 152 neurologically healthy subjects. VOIs from TLE patients, processed in a similar fashion, are projected in this space, and leave-one-out, forward stepwise linear discriminant analysis of the eigencoordinate distributions is used for classification. Following manual MRI volumetric analysis, 80 patients had HC atrophy (group "HA") ipsilateral to the SF (42 with left SF or "LHA", and 38 with right or "RHA"), and the remaining 47 had normal HC volumes (group "HNV") (27 with left SF or "LNV", and 20 with right SF or "RNV"). The automated method was 100% accurate at separating "HA" vs. "HNV", "LHA" vs. "RHA", and "LNV" vs "RNV". It was also 96% accurate at separating "L" vs. "R". Our results indicate that MR data projected in multidimensional feature domains can lateralize SF in epilepsy patients with a high accuracy, irrespective of HC volumes. This single-scan, practical and objective method holds promise for the pre-surgical evaluation of TLE patients.

Adult↗

PubMed2005

Individual voxel-based analysis of gray matter in focal cortical dysplasia.

High-resolution MRI of the brain has made it possible to identify focal cortical dysplasia (FCD) in an increasing number of patients. There is evidence for structural abnormalities extending beyond the visually identified FCD lesion. Voxel-based morphometry (VBM) has the potential of detecting both lesions and extra-lesional abnormalities because it performs a whole brain voxel-wise comparison. However, on T1-weighted MRI, FCD lesions are characterized by a wide spectrum of signal hyperintensity that may compromise the results of the segmentation step in VBM. Our purpose was to investigate gray matter (GM) changes in individual FCD patients using voxel-based morphometry (VBM). In addition, we sought to assess the performance of this technique for FCD detection with respect to lesion intensity using an operator designed to emphasize areas of hyperintense T1 signal. We studied 27 patients with known FCD and focal epilepsy and 39 healthy controls. We compared the GM map of each subject (controls and patients) with the average GM map of all controls and obtained a GM z-score map for each individual. The protocol being designed to achieve a maximal specificity, no differences in GM concentration were found in the control group. The z-score maps showed an increase in GM that coincided with the lesion in 21/27 (78%) patients. Five of the six remaining patients whose lesions were not detected by VBM presented with a strong lesion hyperintensity, and a significant part of their lesion was misclassified as white matter. In 16/27 (59%) patients, there were additional areas of GM increase distant from the primary lesion. Areas of GM decrease were found in 8/27 (30%) patients. In conclusion, individual voxel-based analysis was able to detect FCD in a majority of patients. Moreover, FCD was often associated with widespread GM changes extending beyond the visible lesion. In its current form, however, individual VBM may be unable to detect lesions characterized by strong signal intensity abnormalities.

Adult↗

PubMed2005

Analysis of shape and positioning of the hippocampal formation: an MRI study in patients with partial epilepsy and healthy controls.

The purpose of this study was to evaluate systematically shape and positioning of the hippocampal formation (HF) in patients with partial epilepsy related to malformations of cortical development (MCD) and those with temporal lobe epilepsy (TLE). We studied 76 patients with MCD, including focal cortical dysplasia (n = 29; lesions located outside the temporal lobe in all), heterotopia (lesions outside of the temporal lobe, n = 14; lesions extending into the temporal lobe, n = 16), polymicrogyria (bilateral perisylvian, n = 14; unilateral perisylvian, n = 3) and 30 patients with TLE (hippocampal atrophy, n = 15; normal hippocampal volumes, n = 15). Shape and positioning of the HF were evaluated using a set of eight predefined morphological characteristics. In addition, the degree of hippocampal vertical orientation and medial positioning were assessed quantitatively. Patients were compared with 50 healthy controls. At least three criteria describing abnormal HF shape and positioning were found in 5/50 (10%) healthy controls, 37/76 (49%) MCD and 13/30 (43%) TLE patients. An association with all criteria was found in MCD and TLE, but not in healthy controls. In MCD there was no association between the side of HF shape abnormalities and the side of the cortical malformation or the EEG focus. Likewise, in TLE, HF abnormalities were not related to the side of the EEG focus. In both MCD and TLE patients who had hippocampal atrophy, no association was found between the side of HF shape abnormalities and the side of atrophy. Abnormal HF shape and positioning are found in a similar proportion in MCD and TLE. In TLE, they may be a marker of a more extensive disorder of brain development and may participate in the development of this condition.

Adolescent↗

PubMed2005

Gustatory agnosia.

OBJECTIVE: To report the assessment of a patient exhibiting gustatory agnosia. METHODS: Preoperative and postoperative neuropsychological, neuroimaging, and chemosensory evaluations were performed in a 39-year-old woman undergoing surgical treatment for intractable epilepsy. RESULTS: Preoperative MRIs showed bilateral (right > left) atrophy in the medial temporal lobes and complete atrophy of the left insula. Evaluation of gustatory function revealed normal suprathreshold intensity estimation, affective evaluation, and detection thresholds but elevated recognition thresholds. A functional neuroimaging study showed activation to stimulation of aversive taste in the left amygdala. Surgical treatment entailed resection from the left medial temporal lobe that included the region of amygdala that had responded to taste. Postoperatively, detection, naming, and intensity estimation for taste remained normal, but the patient was unable to recognize different tastes (sweet, sour, salty, and bitter). A second evaluation 2.5 years after her surgery revealed no change in taste ability. CONCLUSION: The anteromedial temporal lobe has an important role in recognizing taste quality.

Adult↗

PubMed2005

Segmentation of focal cortical dysplasia lesions using a feature-based level set.

Focal cortical dysplasia (FCD), a malformation of cortical development, is an important cause of medically intractable epilepsy. FCD lesions are difficult to distinguish from non-lesional cortex and their delineation on MRI is a challenging task. This paper presents a method to segment FCD lesions on T1-weighted MRI, based on a 3D deformable model, implemented using the level set framework. The deformable model is driven by three MRI features: cortical thickness, relative intensity and gradient. These features correspond to the visual characteristics of FCD and allow to differentiate lesions from normal tissues. The proposed method was tested on 18 patients with FCD and its performance was quantitatively evaluated by comparison with the manual tracings of two trained raters. The validation showed that the similarity between the level set segmentation and the manual labels is similar to the agreement between the two human raters. This new approach may become a useful tool for the presurgical evaluation of patients with intractable epilepsy.

Adult↗

PubMed2005

Fetal dextrocardia: diagnosis and outcome in two tertiary centres.

OBJECTIVE: To evaluate the incidence of fetal dextrocardia, associated cardiac and extracardiac malformations, and outcome. DESIGN: Retrospective echocardiographic study. SETTING: Two tertiary centres for fetal cardiology. PATIENTS: 81 consecutive fetuses with a fetal dextrocardia presenting at Guy's Hospital, London, between 1983 and 2003 and at Hôpital Robert Debré, Paris, between 1988 and 2003. Fetal dextrocardia was defined as a condition in which the major axis of the heart points to the right. RESULTS: The incidence was 0.22%. There were 38 fetuses (47%) with situs solitus (SS), 24 (30%) with situs ambiguus (SA), and 19 (23%) with situs inversus (SI). Structural cardiac malformations were found in 25 cases (66%) of SS, 23 cases (96%) of SA, and 12 cases (63%) of SI. Extracardiac malformations were identified in 12 cases (31%) of SS, in five cases (21%) of SA, and in two cases (10%) of SI. Of the 81 cases of fetal dextrocardia, there were 27 interrupted pregnancies (15 of 24 SA, 10 of 38 SS, and 2 of 19 SI), six intrauterine deaths (3 of 38 SS, 2 of 24 SA, and 1 of 19 SI), and five neonatal deaths (3 of 24 SA, 1 of 19 SI, and 1 of 38 SS). There were 43 survivors (24 of 38 SS, 15 of 19 SI, and 4 of 24 SA). CONCLUSION: The majority of fetuses with dextrocardia referred for fetal echocardiography have associated congenital heart disease. There is a broad spectrum of cardiac malformation and the incidence varies according to the atrial situs. Fetal echocardiography enables detection of complex congenital heart disease so that parents can be appropriately counselled.

Chromosome Disorders↗

PubMed2004

Posterior quadrantic dysplasia or hemi-hemimegalencephaly: a characteristic brain malformation.

INTRODUCTION: Posterior quadrantic dysplasia (PQD), a developmental malformation involving the temporal, parietal, and occipital lobes of one cerebral hemisphere, leads to intractable epilepsy. OBJECTIVE: To characterize the clinical features of 19 patients with PQD and analyze the postsurgical outcome of those who underwent resection of dysplastic tissue. METHODS: The extent and nature of the malformation were primarily assessed with high-resolution brain imaging. Fourteen patients underwent complete or partial temporoparieto-occipital resection or temporal resection associated with parieto-occipital disconnection. Postoperative follow-up period ranged from 8 months to 7 years. The authors used the Engel classification for postoperative outcome. RESULTS: All patients were sporadic. Clinical features included infantile spasms, partial seizures, mental retardation, mild hemiparesis, and visual field defects. Neuroimaging localized the malformation within the posterior cerebral quadrant contralateral to the neurologic deficit and demonstrated hemi-hemimegalencephaly in 14 of 19 patients and multilobar cortical dysplasia in 5 of 19 patients. The authors observed class I outcome in six patients. Two patients had class II and four patients had class III outcome. Class IV outcome was seen in two patients. After surgery, two patients developed mild hemiparesis, and two developed a visual field defect. CONCLUSIONS: Widespread cortical dysplasia is more frequent in the posterior quadrant. In our series, posterior quadrantic dysplasia represents either hemi-hemimegalencephaly or multilobar cortical dysplasia. Individuals with posterior quadrantic dysplasia share a spectrum of clinical features. The intractable epilepsy in these patients may be alleviated by a large quadrantic temporoparieto-occipital resection.

Adolescent↗

PubMed2004

GABAA receptor-dependent synchronization leads to ictogenesis in the human dysplastic cortex.

Patients with Taylor's type focal cortical dysplasia (FCD) present with seizures that are often medically intractable. Here, we attempted to identify the cellular and pharmacological mechanisms responsible for this epileptogenic state by using field potential and K+-selective recordings in neocortical slices obtained from epileptic patients with FCD and, for purposes of comparison, with mesial temporal lobe epilepsy (MTLE), an epileptic disorder that, at least in the neocortex, is not characterized by any obvious structural aberration of neuronal networks. Spontaneous epileptiform activity was induced in vitro by applying 4-aminopyridine (4AP)-containing medium. Under these conditions, we could identify in FCD slices a close temporal relationship between ictal activity onset and the occurrence of slow interictal-like events that were mainly contributed by GABAA receptor activation. We also found that in FCD slices, pharmacological procedures capable of decreasing or increasing GABAA receptor function abolished or potentiated ictal discharges, respectively. In addition, the initiation of ictal events in FCD tissue coincided with the occurrence of GABAA receptor-dependent interictal events leading to [K+]o elevations that were larger than those seen during the interictal period. Finally, by testing the effects induced by baclofen on epileptiform events generated by FCD and MTLE slices, we discovered that the function of GABAB receptors (presumably located at presynaptic inhibitory terminals) was markedly decreased in FCD tissue. Thus, epileptiform synchronization leading to in vitro ictal activity in the human FCD tissue is initiated by a synchronizing mechanism that paradoxically relies on GABAA receptor activation causing sizeable increases in [K+]o. This mechanism may be facilitated by the decreased ability of GABAB receptors to control GABA release from interneuron terminals.

4-Aminopyridine↗

PubMed2004

Prenatal rupture of a left ventricular diverticulum: a case report and review of the literature.

Congenital left ventricular diverticulum is a rare malformation. We report a case of a ruptured congenital left ventricular diverticulum in a 24-week-old fetus. The fetus was referred for a large and circumferential pericardial effusion confirmed by cross-sectional echocardiography in our tertiary fetal cardiology unit. Pericardiocentesis removed 25 mL of old hematic fluid. The fetus died 5 days later. The pathological examination showed a ruptured submitral fibrous diverticulum of the posterior wall of the left ventricle. There is no previous report in the literature of prenatal rupture of a cardiac diverticulum. The submitral location and the fibrous wall of the diverticulum is uncommon. As regards this case, we reviewed the diagnostic criteria and the outcome of 11 cases of prenatal cardiac diverticulum reported in the literature.

Adult↗

PubMed2004

Whole-brain voxel-based statistical analysis of gray matter and white matter in temporal lobe epilepsy.

Volumetric MRI studies based on manual labeling of selected anatomical structures have provided in vivo evidence that brain abnormalities associated with temporal lobe epilepsy (TLE) extend beyond the hippocampus. Voxel-based morphometry (VBM) is a fully automated image analysis technique allowing identification of regional differences in gray matter (GM) and white matter (WM) between groups of subjects without a prior region of interest. The purpose of this study was to determine whole-brain GM and WM changes in TLE and to investigate the relationship between these abnormalities and clinical parameters. We studied 85 patients with pharmacologically intractable TLE and unilateral hippocampal atrophy and 47 age- and sex-matched healthy control subjects. The seizure focus was right sided in 40 patients and left sided in 45. Student's t test statistical maps of differences between patients' and controls' GM and WM concentrations were obtained using a general linear model. A further regression against duration of epilepsy, age of onset, presence of febrile convulsions, and secondary generalized seizures was performed with the TLE population. Voxel-based morphometry revealed that GM pathology in TLE extends beyond the hippocampus involving other limbic areas such as the cingulum and the thalamus, as well as extralimbic areas, particularly the frontal lobe. White matter reduction was found only ipsilateral to the seizure focus, including the temporopolar, entorhinal, and perirhinal areas. This pattern of structural changes is suggestive of disconnection involving preferentially frontolimbic pathways in patients with pharmacologically intractable TLE.

Adolescent↗

PubMed2003

Magnetic resonance spectroscopy and imaging of the thalamus in idiopathic generalized epilepsy.

Experimental work in animal models of generalized epilepsy and clinical data in humans with idiopathic generalized epilepsy (IGE) indicate that the thalamo-cortical circuitry is involved in the generation of epileptic activity. The purpose of this study was to evaluate in vivo the chemical and structural integrity of the thalamus in patients with IGE. Thalamic proton magnetic resonance spectroscopic imaging (1H-MRSI), measuring N-acetylaspartate (NAA), choline-containing compounds and creatine (Cr) was performed in 20 IGE patients and in a group of age-matched healthy subjects. Additionally, 1H-MRSI measurements were taken in the insular cortex, the posterior temporal lobe white matter and the splenium of the corpus callosum. MRI volumetric analysis of the thalamus was performed in all patients. At the time of the examination, seizures were well controlled in 10 IGE patients and poorly controlled in nine. One patient was newly diagnosed and had the MRI and MRSI examination prior to starting the antiepileptic medication. In IGE patients, 1H-MRSI showed a reduction of mean thalamic NAA/Cr compared with normal controls; no difference was found in NAA/Cr in the other examined areas. There was no difference in NAA/Cr between patients whose seizures were well controlled and those in whom seizures were not controlled. There was no correlation between thalamic NAA/Cr and mean number of spike and wave complexes. We found a significant negative correlation between thalamic NAA/Cr and duration of epilepsy. The mean thalamic volume in patients with IGE was not different from normal controls. These results show evidence of progressive thalamic neuronal dysfunction in patients with IGE supporting the notion of abnormal thalamo-cortical circuitry as a substrate of seizure generation in this form of epilepsy. The thalamic dysfunction may occur regardless of amount of spike and wave activity.

Adult↗

PubMed2003

Intractable temporal lobe epilepsy with rare spikes is less severe than with frequent spikes.

OBJECTIVE: To analyze clinical, electrophysiologic, and neuroradiologic characteristics of a group of patients with nonlesional intractable temporal lobe epilepsy (TLE) and rare or absent interictal epileptiform abnormalities (IEA). METHODS: Between 1990 and 2000, 31 patients (11 men; mean +/- SD age 34.3 +/- 11.7 years) with nonlesional intractable TLE were consecutively selected on the basis of the absence or paucity of IEA (<1/h) on serial scalp EEG recording; these were defined as "oligospikers." The clinical and laboratory characteristics of oligospikers were compared with those of a group of 27 age-matched control subjects (10 men; mean +/- SD age 38.5 +/- 11 years), randomly selected from a pool of patients with nonlesional TLE with frequent IEA. RESULTS: Oligospikers showed a later age at seizure onset (mean +/- SD 19.1 +/- 14.4 versus 10.2 +/- 7.4 years; p = 0.004), lower monthly frequency of complex partial seizures (median 6 versus 12; p = 0.035), lower incidence of secondarily generalized tonic-clonic seizures (10 versus 81%; p < 0.001), and no status epilepticus (0 versus 22%) than control subjects. Also, hippocampal atrophy (HA) was less commonly found in oligospikers (55 versus 96%; p = 0.001). However, there were no differences between the two groups in the frequency of family history of epilepsy, risk factors, febrile convulsions, and type of medication. Twenty-three (74%) oligospikers and 25 (93%) control patients underwent either a selective amygdalohippocampectomy or corticoamygdalohippocampectomy. Excellent surgical outcome (Engel's Class Ia) was found in 14 of 23 (61%) oligospikers and 17 of 25 (67%) control patients. CONCLUSIONS: This study identified a subgroup of patients with nonlesional intractable TLE with no or few IEA. Oligospikers have a later age at seizure onset, less frequent and less severe seizures, besides a lower incidence of HA. The similarity of etiologic factors compared with patients with frequent IEA suggests that the rarity of spikes could reflect a disease not really distinct but less severe, even though still intractable and incapacitating enough to consider surgery. In spite of the absence or paucity of IEA, oligospikers have excellent surgical outcome.

Adult↗

PubMed2003

Alpha-[11C] methyl-L-tryptophan and glucose metabolism in patients with temporal lobe epilepsy.

OBJECTIVE: To determine whether metabolism in the brain serotonergic system, including the kynurenine pathway, is involved in temporal lobe epilepsy (TLE). METHODS: The authors studied 14 patients with intractable TLE by PET using alpha-[11C] methyl-L-tryptophan (alpha-MTrp) and 2-[18F]-fluoro-deoxy-glucose (FDG) and compared results with 21 healthy control subjects who had alpha-MTrp PET studies. Seven patients had unilateral hippocampal atrophy (HA), and seven had normal hippocampal volumes (NV). The regional uptake constant (K*) for alpha-MTrp and regional FDG uptake were calculated in regions with high serotonergic innervation, including the hippocampus, amygdala, lateral temporal lobe, frontal lobe, thalamus, lenticular nucleus, and cingulate cortex. RESULTS: A significant increase of alpha-MTrp uptake was observed in the hippocampus ipsilateral to the seizure focus in seven TLE patients with NV compared to seven patients with HA as well as to healthy controls. In patients with TLE, glucose utilization in the lateral temporal lobe ipsilateral to the seizure focus was correlated negatively with K* for alpha-MTrp in the ipsilateral hippocampus and positively with K* in the ipsilateral lenticular nucleus and cingulate cortex. Glucose utilization in the frontal lobe ipsilateral to the seizure shows a reduction in the glucose utilization which relates to the increase in the alpha-MTrp uptake in the ipsilateral lateral temporal lobe. CONCLUSION: This study demonstrates dysfunction of the serotonergic system, which could include metabolism through the kynurenine pathway in TLE patients with normal hippocampal volumes. alpha-MTrp PET studies might be useful for lateralizing the epileptic focus in TLE patients with normal hippocampal volumes.

Adolescent↗