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Biomedical subjects

F Cendes

Publications and source records attributed to F Cendes.

At least 91 records · Page 5Linked to original sources
PubMed1995

The relation of spike foci and of clinical seizure characteristics to different patterns of mesial temporal atrophy.

We reviewed clinical data and scalp electroencephalograms in 61 consecutive patients with temporal lobe epilepsy and mesial temporal atrophy assessed with volumetric magnetic resonance imaging: 39 patients had unilateral and 22 patients had bilateral atrophy. We attempted to determine whether any aspects of seizure symptoms and any electrographic features could be correlated to degree and anatomic pattern of mesial temporal atrophy. Spikes were always confined to temporal regions and were frequently bilateral without a statistically significant difference between patients with unilateral atrophy (33%) and those with bilateral atrophy (50%). Twenty-five of 40 foci associated with amygdala atrophy had maximum field over the anterior temporal regions. In contrast, 19 of 19 foci with isolated hippocampal formation atrophy were never maximum anteriorly. Secondarily generalized seizures and temporal lobe syncopes were correlated with anatomically extensive, particularly amygdala, atrophy. Prolonged postictal confusion was always associated with bitemporal abnormalities in the form of atrophy or spiking. These results explain some of the variability in the clinical and electrographic manifestations of temporal epilepsy and outline the specific role of amygdala involvement in addition to the commonly reported hippocampal atrophy.

Action Potentials↗
PubMed1995

Temporal lobe epilepsy caused by domoic acid intoxication: evidence for glutamate receptor-mediated excitotoxicity in humans.

We describe the development of temporal lobe epilepsy in an 84-year-old man who had suffered domoic acid intoxication. Following intoxication he had nausea, vomiting, confusion, and coma. Generalized convulsions and complex partial status epilepticus progressively developed. After 3 weeks he improved and was seizure free with severe residual memory deficit. Electroencephalograms initially showed periodic epileptiform discharges, later evolving to epileptic abnormalities over frontotemporal regions with diffuse slow waves. Eight months after the intoxication the electroencephalogram was normal. One year after the acute episode, complex partial seizures developed. Electroencephalograms showed epileptic discharges independently over both temporal lobes, with left-sided predominance. Magnetic resonance imaging revealed a hyperintense T2-weighted signal and atrophy of both hippocampi; a positron emission tomographic scan showed bitemporal decreased glucose metabolism. Pneumonia developed and the patient died 3 1/4 years after the intoxication. Autopsy disclosed severe bilateral hippocampal sclerosis. The seizures following acute domoic acid intoxication, the postmortem pathology, and the fact that temporal lobe epilepsy developed 1 year after intoxication indicate that the human hippocampus is also vulnerable to kainate receptor excitotoxicity, and provide strong evidence supporting the role of excitotoxic injury in epileptogenesis. This report provides a unique human parallel to, and validates the animal model of, kainate-induced epilepsy as an important tool for studying temporal lobe epilepsy.

Aged↗
PubMed1995

Curvilinear reconstruction of 3D magnetic resonance imaging in patients with partial epilepsy: a pilot study.

In an attempt to better delineate the abnormalities associated with focal cortical dysgenesis, we performed curvilinear reformatting of the cortex from 3D magnetic resonance (MR) images. Illustrative patients with partial seizures and conventional orthogonal MRI evaluation show that small regions of cortical thickening suggestive of focal dysplastic lesions may not be recognized. In three such patients the curvilinear reformatting demonstrated two additional focal abnormalities of the cortical gyri and better defined the two focal lesions found on conventional orthogonal MR images. This method promises to be a useful tool in the evaluation of epileptic patients with proven or suspected subtle structure cortical abnormalities, particularly focal neuronal migration disorders where cortical thickening, abnormal gyral pattern, and poor delineation of the gray-white matter transition are the main findings.

Brain Damage, Chronic↗
PubMed1995

Proton magnetic resonance spectroscopic images and MRI volumetric studies for lateralization of temporal lobe epilepsy.

We obtained 2D magnetic resonance (MR) spectroscopic images (MRSI) and MRI volumetric measurements (MRIV) of amygdala and hippocampus in 30 consecutive patients with temporal lobe epilepsy (TLE) being evaluated for surgical treatment. Both MRSI and MRIV lateralization showed good agreement with the current gold standard of clinical-EEG lateralization. Each exam separately correctly lateralized 25 out of 30 patients with no false lateralization. Combining both exams, lateralization could be achieved in 28 out of 30 patients. The two patients with no significant asymmetry had bitemporal EEG abnormalities, and bilateral damage on both MRIV and MRSI. There was a good correlation between the magnitude of the MRSI and MRIV asymmetry (Pearson coefficient = 0.83; p < .0001). Both MRSI and MRIV were normal in our patients with seizures originating outside the temporal lobes. Both MRIV and MRSI can lateralize TLE in 83% of patients. Combination of the two modalities allows lateralization in 93% of patients. Patients who cannot be lateralized generally have symmetrical bitemporal abnormalities; they are not incorrectly lateralized. The structural and chemical pathologic abnormalities seen in TLE seem to be associated with the seizure focus, and may be as, or even more, reliable than a few recorded seizures in predicting the side from which most seizures originate.

Adult↗
PubMed1995

Genetic linkage studies in familial frontal epilepsy: exclusion of the human chromosome regions homologous to the El-1 mouse locus.

Familial frontal epilepsy has been recently described in six pedigrees. All families reported show autosomal dominant inheritance with incomplete penetrance. Affected individuals develop predominantly nocturnal seizures with frontal lobe semiology. In 1959, a genetic mouse model for partial epilepsy, the El mouse, was reported. In the El mouse, a major seizure susceptibility gene, El-1, segregates in an autosomal dominant fashion and has been localized to a region distal to the centromere of mouse ch 9. Comparative genetic maps between man and mouse have been used to predict the location of several human disease genes. The El-1 locus in the mouse is homologous to human chromosomes 3p23-p21.2, 3p11.2-q11.2, 3q21-q25.3, 6p12-q12 and 15q24. Polymorphic microsatellite markers covering these candidate regions were used for genotyping individuals in the three larger families ascertained, one of which is French-Canadian and two are Australian. Significant negative two-point and multipoint lod scores were obtained separately for each family, thus excluding linkage with the candidate regions on chromosomes 3, 6 and 15.

Animals↗
PubMed1995

Autosomal dominant nocturnal frontal lobe epilepsy. A distinctive clinical disorder.

The disorder of autosomal dominant nocturnal frontal lobe epilepsy has recently been identified, and is now delineated in detail. A phenotypically homogeneous group of five families from Australia, Britain and Canada, containing 47 affected individuals, was studied. The largest family contained 25 affected individuals spanning six generations. This disorder is characterized by clusters of brief nocturnal motor seizures, with hyperkinetic or tonic manifestations. Subjects often experienced an aura, and remained aware throughout the attacks. Seizures occurred in clusters (mean eight attacks/night) typically as the individual dozed, or shortly before awakening. The epilepsy usually began in childhood, and persisted through adult life, with considerable intra-family variation in severity. Seizures were often misdiagnosed as benign nocturnal parasomnias, psychiatric and medical disorders. Interictal EEG studies were unhelpful. Ictal video-EEG studies showed that the attacks were partial seizures with frontal lobe seizure semiology. Neuro-imaging was normal. Carbamazepine monotherapy was frequently effective. This disorder showed autosomal dominant inheritance. Recognition of this entity is clinically important for diagnosis, appropriate therapy and genetic counselling. Moreover, this disorder now offers an opportunity to identify a gene for partial epilepsy.

Adolescent↗
PubMed1995

Imaging of axonal damage in vivo in Rasmussen's syndrome.

We obtained magnetic resonance spectroscopic images (MRSIs) in three patients with Rasmussen's syndrome. The relative resonance intensity of N-acetylaspartate (NAA) to creatine (NAA:Cr), an index of neuronal loss or damage, was determined for various regions within the brain, and the affected:unaffected hemisphere asymmetry ratio was determined. All three patients had decreased relative NAA signal intensity over the entire affected hemisphere. The decrease in NAA:Cr involved cortex and white matter, was most prominent in the anterior periventricular region, and showed a tendency to be worse in patients with longer duration of disease. 1 year follow-up MRSI showed further reduction of the relative NAA signal in all patients, indicating progression of the disease. All patients were free of seizures for at least 48 h before the first MRSI, but two of them had epilepsia partialis continua (EPC) during the follow-up examination. There was no significant increase of the lactate resonance intensity, except in the two MRSIs performed during EPC. This indicates that lactate accumulation results from repetitive seizures rather than from the disease process itself. The spatial distribution of the metabolic abnormality on MRSI was more widespread than that of the structural abnormality on MRI. The relative NAA resonance intensity was not reduced in the contralateral hemisphere. Our findings indicate that MRSI can identify and quantify neuronal damage and loss throughout the affected hemisphere of patients with Rasmussen's syndrome, including areas that appear normal on conventional MRI.

Adolescent↗
PubMed1995

Focal intermittent delta activity in patients with mesiotemporal atrophy: a reliable marker of the epileptogenic focus.

We attempted to determine the significance of background abnormalities and their relation with spikes and location of atrophy in 56 patients with temporal lobe epilepsy (TLE) and mesiotemporal atrophy (MTA) assessed by volumetric magnetic resonance imaging (MRI): 35 patients had unilateral (group I) and 21 had bilateral atrophy with lateralized predominance (group II). Trains of delta waves over temporal regions were observed in > or = 90% of patients. They lateralized with accuracy equal to that of the spikes to the site of atrophy (delta 92% or 29 of 32 patients in group I and 63% or 12 of 19 of group II; spikes 85% or 28 of 33 of group I and 65% or 13 of 20 of group II). Delta waves and spikes occurred together in > 85% of cases. With respect to their location, a striking concordance was observed: delta activity almost always occurred ipsilateral with unilateral spiking (90% or 19 of 21 of patients with unilateral and 88% or 7 of 8 of patients with bilateral atrophy) and bilaterally independently with bilateral spiking (67% or 6 of 9 of patients in group I and 100% or 10 of 10 in group II). Furthermore, spiking and delta activity were never in disagreement with respect to lateralization. In TLE related to MTA, delta transients are a reliable indicator of the epileptogenic focus and presumably reflect the epileptogenic process rather than the underlying structural pathology.

Adolescent↗
PubMed1995

Frequency and characteristics of dual pathology in patients with lesional epilepsy.

We studied 167 patients who had identifiable lesions and temporal or extratemporal partial epilepsy. Pathology included neuronal migration disorders (NMDs) (48), low-grade tumors (52), vascular malformations (34), porencephalic cysts (16), and gliotic lesions as a result of cerebral insults early in life (17). MRI volumetric studies using thin (1.5- or 3-mm) coronal images were performed in all patients and in 44 age-matched normal controls. An atrophic hippocampal formation (HF), indicating dual pathology, was present in 25 patients (15%). Abnormal HF volumes were present in those with lesions involving temporal (17%) but also extratemporal (14%) areas. Age at onset and duration of epilepsy did not influence the presence of HF atrophy. However, febrile seizures in early childhood were more frequently, although not exclusively, found in patients with hippocampal atrophy. The frequency of hippocampal atrophy in our patients with low-grade tumors (2%) and vascular lesions (9%) was low. Dual pathology was far more common in patients with NMDs (25%), porencephalic cysts (31%), and reactive gliosis (23.5%). Some structural lesions, such as NMDs, are more likely to be associated with hippocampal atrophy, independent of the distance of the lesion from the HF. In other types of lesions, such as vascular malformations, dual pathology was found when the lesion was close to the HF. A common pathogenic mechanism during pre- or perinatal development may explain the occurrence of concomitant mesial temporal sclerosis and other structural lesions because of either (1) associated developmental abnormalities or (2) predisposition to prolonged febrile convulsions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Autosomal dominant frontal epilepsy misdiagnosed as sleep disorder.

We describe a distinctive epilepsy syndrome in six families, which is the first partial epilepsy syndrome to follow single gene inheritance. The predominant seizure pattern had frontal lobe seizure semiology with clusters of brief motor attacks occurring in sleep. Onset was usually in childhood, often persisting through adult life. Misdiagnosis as night terrors, nightmares, hysteria, or paroxysmal nocturnal dystonia was common, and the inheritance pattern was often not appreciated. This autosomal dominant epilepsy syndrome is ideal for identification of partial epilepsy genes.

Adolescent↗
PubMed1994

Lateralization of temporal lobe epilepsy based on regional metabolic abnormalities in proton magnetic resonance spectroscopic images.

Magnetic resonance spectroscopic imaging (MRSI) is capable of determining the spatial distribution in vivo of cerebral metabolites, including N-acetylaspartate (NAA), a compound found only in neurons. We used this technique in 10 patients with temporal lobe epilepsy (TLE) to determine the location of maximal neuronal/axonal loss or damage and to evaluate the potential of MRSI for presurgical lateralization. Asymmetry of the relative resonance intensity of NAA to creatine was determined for mid and posterior regions of the temporal lobes defined anatomically and also for "metabolic lesions" defined as the regions of maximal abnormality on MRSI. MRSI revealed decreased relative signal intensity in at least one temporal lobe of all patients. Two patients had a widespread reduction in NAA in both temporal lobes. The region of maximal abnormality was usually in the posterior temporal lobe but sometimes in the mid temporal lobe. The side of lowest NAA was ipsilateral to the clinical electroencephalographic lateralization in all patients. Lateralization based on NAA to creatine correlated with the atrophy of amygdala and hippocampus in 8 patients who showed this on magnetic resonance imaging volumetric measurements. MRSI can demonstrate regional neuronal loss or damage that correlates with clinical electroencephalographic and structural lateralization in temporal lobe epilepsy. The ability to identify a region of maximal metabolic abnormality on spectroscopic images may confer greater sensitivity than that available from single voxel methods. The maximal metabolic abnormality may not be located in a voxel defined a priori, and based on anatomical considerations, without knowledge of the distribution of the metabolic abnormality.

Adult↗
PubMed1994

Relationship between atrophy of the amygdala and ictal fear in temporal lobe epilepsy.

Viscerosensory and affective manifestations are often elicited by temporal lobe seizure discharges. They have been reproduced by amygdaloid stimulation in awake patients during stereotaxic exploration or neurosurgical procedures. They are not exclusively reproduced by stimulation of the amygdala, though most commonly they are evoked from it. Ictal fear is frequently, but not invariably, associated with a rising epigastric sensation, palpitations, mydriasis and pallor. We studied 50 patients (mean age 33 years) with intractable temporal lobe epilepsy (TLE): MRI volumetric measurements of amygdala and hippocampus were performed using a protocol previously described by our group (Watson et al., Neurology 1992; 42: 1743-50). All patients had extensive EEG investigation and at least two seizures recorded by video-EEG monitoring. Seventeen patients (34%) had a clear history of fear accompanied by a rising epigastric sensation as the initial manifestation of their habitual attacks. The amygdala volumes in this group were significantly (P = 0.001) smaller (mean 2131.6 mm3) compared with the volumes of the 33 patients without these symptoms (mean 2561.5 mm3). Both patient groups had smaller mean amygdala volumes compared with normal controls (mean 2828.2 mm3). Postoperative pathology correlated well with volumetric atrophy. In addition, we found that patients with more pronounced amygdaloid atrophy more commonly had prolonged febrile convulsions in early childhood and also more frequently secondarily generalized seizures. Results support the finding that ictal fear is related to pathology of the amygdala and that it, like the hippocampus, is an important substrate of TLE.

Adolescent↗
PubMed1994

Late-onset drop attacks in temporal lobe epilepsy: a reevaluation of the concept of temporal lobe syncope.

We report the clinical, radiologic, and EEG features of six patients with temporal lobe drop attacks (TLDA), all of whom underwent temporal resection. Postoperative follow-up of at least 1 year was available in all. TLDA were never the first manifestation but followed the onset of epilepsy after a long delay ranging from 7 to 43 years (mean, 24.4 years). Seizures were of unilateral temporal origin. In one patient, stereo EEG recording of TLDA showed rapid spread of the ictal discharge away from the temporal lobe in less than 1 second. Postoperatively, three patients were seizure free; one has had no TLDA but experiences sporadic auras; another, despite a reduction of more than 50%, continues to have complex partial seizures and TLDA; and the sixth has had sporadic secondarily generalized seizures upon reduction of antiepileptic medication. In conclusion, drop attacks may occur in temporal lobe epilepsy, usually long after the onset of epilepsy. They lead to increased disability and suggest a rapid spread of the ictal discharge and possible involvement of the pontine reticular formation rather than the presence of bitemporal foci or an extratemporal origin.

Adult↗
PubMed1994

Confirmation of the SCA-2 locus as an alternative locus for dominantly inherited spinocerebellar ataxias and refinement of the candidate region.

The autosomal dominant spinocerebellar ataxias (SCAs) are a clinically heterogeneous group of neurodegenerative diseases. To date, two SCA loci have been identified-one locus (SCA-1) on the short arm of chromosome 6 and the second locus (SCA-2) on the long arm of chromosome 12. We have studied two large kindreds from different ethnic backgrounds, segregating an autosomal dominant form of SCA. A total of 207 living individuals, including 50 affected, were examined, and blood was collected. We performed linkage analysis using anonymous DNA markers which flank the two previously described loci. Our results demonstrate that the two kindreds, one Austrian-Canadian and one French-Canadian, are linked to SCA-2 (chromosome 12q). Multipoint linkage analysis places the SCA-2 locus within a region of approximately 16 cM between the microsatellites D12S58 and D12S84/D12S105 (odds ratio 2,371:1 in favor of this position). We show that the SCA-2 locus is not a private gene and represents an alternative SCA locus.

Austria↗
PubMed1993

Atrophy of mesial structures in patients with temporal lobe epilepsy: cause or consequence of repeated seizures?

We studied 70 epileptic patients by using magnetic resonance imaging volumetric measurements of amygdala (AM) and hippocampal formation (HF). Fifty patients presented with intractable temporal lobe epilepsy (TLE), 10 patients had focal extratemporal lobe epilepsy, and 10 had generalized epilepsy. In 91% of the 45 TLE patients without foreign tissue lesions, there was significant smallness of the AM and/or HF coinciding with the side of electroencephalographic seizure onset. No significant smallness or asymmetry was demonstrated in patients with focal extratemporal or generalized epilepsy. We performed a linear regression analysis, plotting the number of years of recurrent seizures and the estimated seizure frequency against the volumes of the AM and HF. There was no correlation between either of these two parameters and AM or HF volume (p > 0.9). There was also no correlation between the patient's age and volumetric measurements of AM or HF, nor did these measurements correlate with the occurrence of generalized seizures. On the other hand, patients with antecedent prolonged febrile convulsions in early childhood had significantly smaller AM and HF, compared with those without such a history (p < 0.001). The findings indicate that repeated seizures or longer duration of epilepsy do not cause increased atrophy of AM or HF that is measurable by volumetric magnetic resonance imaging.

Adolescent↗
PubMed1993

Increased neocortical spiking and surgical outcome after selective amygdalo-hippocampectomy.

We studied the electrocorticogram (ECoG) before and immediately after transcortical selective amygdalo-hippocampectomy, prospectively in 13 consecutive patients and retrospectively in three others. ECoG was performed with surface and two depth electrodes inserted through T2 aimed at the amygdala and anterior hippocampus. Before resection the ECoG showed a variable amount of interictal spiking, recorded either independently from the depth and surface, or synchronously. A small cortical incision (2-3 cm) was made in T2. The hippocampus, amygdala and parahippocampal gyrus were removed subpially. After the resection, increased epileptiform abnormality was observed in all 16 patients and a different ECoG pattern emerged. It consisted of repetitive, high amplitude spikes and polyspikes, separated by attenuated background, recorded from the most anterior temporal area. Similar observations were reported by Niemeyer in 1958. The outcome was comparable to that of standard anterior temporal resection: 62.5% class I and 25% class II (Engel's scale). ECoG is often used to tailor the amount of resection, and the persistence of epileptic abnormalities correlates with worse outcome. This is not the case in selective amygdalo-hippocampectomy, suggesting that a different underlying mechanism is responsible for the increased interictal spiking following this procedure.

Adolescent↗
PubMed1993

MRI volumetric measurement of amygdala and hippocampus in temporal lobe epilepsy.

We performed MRI volumetric measurements of the amygdala (AM), the hippocampal formation (HF), and the anterior temporal lobe in a group of 30 patients with intractable temporal lobe epilepsy (TLE) and in seven patients with extratemporal lobe foci. Measurements were analyzed with a semiautomated software program and the results compared with those of normal controls and correlated with the findings of all other investigations. In particular, we compared the results with the lateralization of epileptic abnormalities in the EEG. Volumetric studies of AM and HF showed lateralization of measurable atrophy consistent with that derived from extracranial and intracranial EEG examinations. The HF volumes were more sensitive and provided a lateralization in 87%. Combined measurements of AM and HF showed lateralization in 93%, always congruent with the results of EEG lateralization. This slight but important additional improvement in discrimination justifies using AM measurements in MRI volumetric studies of mesial temporal structures. Volumetric studies combined with other currently employed noninvasive techniques may diminish the need for invasive methods of investigation in patients with TLE.

Adult↗