WorldWideScience

Sample records for amytal

  1. Determination of hemisphere dominance for language: comparison of frontal and temporal fMRI activation with intracarotid amytal testing

    International Nuclear Information System (INIS)

    The reliability of frontal and temporal fMRI activations for the determination of hemisphere language dominance was evaluated in comparison with intracarotid amytal testing (IAT). Twenty-two patients were studied by IAT (bilateral in 13, unilateral in 9 patients) and fMRI using a paradigm requiring semantic decisions. Global and regional (frontal and temporoparietal) lateralisation indices (LI) were calculated from the number of activated (r>0.4) voxels in both hemispheres. Frontolateral activations associated with the language task were seen in all patients, temporoparietal activations in 20 of 22. Regional LI corresponded better with IAT results than global LI. Frontolateral LI were consistent with IAT in all patients with bilateral IAT (including three patients with right dominant and one patient with bilateral language representation) and were not conflicting in any of the patients with unilateral IAT. Temporoparietal LI were discordant with IAT in two patients with atypical language representation. In the determination of hemisphere dominance for language, regional analysis of fMRI activation is superior to global analysis. In cases with clear-cut fMRI lateralisation, i.e. consistent lateralised activation of frontal and temporoparietal language zones, IAT may be unnecessary. FMRI should be performed prior to IAT in all patients going to be operated in brain regions potentially involved in language. (orig.)

  2. Determination of hemisphere dominance for language: comparison of frontal and temporal fMRI activation with intracarotid amytal testing

    Energy Technology Data Exchange (ETDEWEB)

    Spreer, J.; Arnold, S.; Ziyeh, S.; Klisch, J.; Schumacher, M. [Section of Neuroradiology, Neurozentrum, University of Freiburg (Germany); Quiske, A.; Altenmueller, D.; Schulze-Bonhage, A. [Section for Presurgical Epilepsy Diagnosis, Neurozentrum, University of Freiburg (Germany); Wohlfarth, R.; Steinhoff, B.J. [Epilepsiezentrum, Kehl-Kork (Germany); Herpers, M.; Kassubek, J. [Department of Neurology, Neurozentrum, University of Freiburg (Germany); Honegger, J. [Department of Neurosurgery, Neurozentrum, University of Freiburg (Germany)

    2002-06-01

    The reliability of frontal and temporal fMRI activations for the determination of hemisphere language dominance was evaluated in comparison with intracarotid amytal testing (IAT). Twenty-two patients were studied by IAT (bilateral in 13, unilateral in 9 patients) and fMRI using a paradigm requiring semantic decisions. Global and regional (frontal and temporoparietal) lateralisation indices (LI) were calculated from the number of activated (r>0.4) voxels in both hemispheres. Frontolateral activations associated with the language task were seen in all patients, temporoparietal activations in 20 of 22. Regional LI corresponded better with IAT results than global LI. Frontolateral LI were consistent with IAT in all patients with bilateral IAT (including three patients with right dominant and one patient with bilateral language representation) and were not conflicting in any of the patients with unilateral IAT. Temporoparietal LI were discordant with IAT in two patients with atypical language representation. In the determination of hemisphere dominance for language, regional analysis of fMRI activation is superior to global analysis. In cases with clear-cut fMRI lateralisation, i.e. consistent lateralised activation of frontal and temporoparietal language zones, IAT may be unnecessary. FMRI should be performed prior to IAT in all patients going to be operated in brain regions potentially involved in language. (orig.)

  3. MRI language dominance assessment in epilepsy patients at 1.0 T: region of interest analysis and comparison with intracarotid amytal testing

    Energy Technology Data Exchange (ETDEWEB)

    Deblaere, K.; Vandemaele, P.; Tieleman, A.; Achten, E. [Department of Neuroradiology, Ghent University Hospital, De Pintelaan 185, 9000, Ghent (Belgium); Boon, P.A.; Vonck, K. [Reference Center for Refractory Epilepsy of the Department of Neurology, Ghent University Hospital, Ghent (Belgium); Vingerhoets, G. [Labaratory for Neuropsychology, Neurology Section of the Department of Internal Medicine, Ghent University, Ghent (Belgium); Backes, W. [Department of Neuroradiology, University Hospital Maastricht, Maastricht (Netherlands); Defreyne, L. [Department of Interventional Radiology, Ghent University Hospital, Ghent (Belgium)

    2004-06-01

    The primary goal of this study was to test the reliability of presurgical language lateralization in epilepsy patients with functional magnetic resonance imaging (fMRI) with a 1.0-T MR scanner using a simple word generation paradigm and conventional equipment. In addition, hemispherical fMRI language lateralization analysis and region of interest (ROI) analysis in the frontal and temporo-parietal regions were compared with the intracarotid amytal test (IAT). Twenty epilepsy patients under presurgical evaluation were prospectively examined by both fMRI and IAT. The fMRI experiment consisted of a word chain task (WCT) using the conventional headphone set and a sparse sequence. In 17 of the 20 patients, data were available for comparison between the two procedures. Fifteen of these 17 patients were categorized as left hemispheric dominant, and 2 patients demonstrated bilateral language representation by both fMRI and IAT. The highest reliability for lateralization was obtained using frontal ROI analysis. Hemispherical analysis was less powerful and reliable in all cases but one, while temporo-parietal ROI analysis was unreliable as a stand-alone analysis when compared with IAT. The effect of statistical threshold on language lateralization prompted for the use of t-value-dependent lateralization index plots. This study illustrates that fMRI-determined language lateralization can be performed reliably in a clinical MR setting operating at a low field strength of 1 T without expensive stimulus presentation systems. (orig.)

  4. MRI language dominance assessment in epilepsy patients at 1.0 T: region of interest analysis and comparison with intracarotid amytal testing

    International Nuclear Information System (INIS)

    The primary goal of this study was to test the reliability of presurgical language lateralization in epilepsy patients with functional magnetic resonance imaging (fMRI) with a 1.0-T MR scanner using a simple word generation paradigm and conventional equipment. In addition, hemispherical fMRI language lateralization analysis and region of interest (ROI) analysis in the frontal and temporo-parietal regions were compared with the intracarotid amytal test (IAT). Twenty epilepsy patients under presurgical evaluation were prospectively examined by both fMRI and IAT. The fMRI experiment consisted of a word chain task (WCT) using the conventional headphone set and a sparse sequence. In 17 of the 20 patients, data were available for comparison between the two procedures. Fifteen of these 17 patients were categorized as left hemispheric dominant, and 2 patients demonstrated bilateral language representation by both fMRI and IAT. The highest reliability for lateralization was obtained using frontal ROI analysis. Hemispherical analysis was less powerful and reliable in all cases but one, while temporo-parietal ROI analysis was unreliable as a stand-alone analysis when compared with IAT. The effect of statistical threshold on language lateralization prompted for the use of t-value-dependent lateralization index plots. This study illustrates that fMRI-determined language lateralization can be performed reliably in a clinical MR setting operating at a low field strength of 1 T without expensive stimulus presentation systems. (orig.)

  5. Provocative Testing for Embolization of Spinal Cord AVMs

    OpenAIRE

    Niimi, Y.; Sala, F; Deletis, V; Berenstein, A.

    2000-01-01

    The purpose of this study is to evaluate efficacy and reliability of chemical provocative testing using neurophysiological monitoring prior to embolization of spinal cord AVMs (SCAVMs). We performed retrospective analysis of provocative testing using sodium amytal and lidocaine injected superselectively in 41 angiography and/ or embolization procedures in 26 patients with a SCAVM, including 23 amytal and 26 lidocaine injections. All procedures were performed under general anesthesia using neu...

  6. Histochemical technique for the demonstration of phosphofructokinase activity in heart and skeletal muscles.

    Science.gov (United States)

    Meijer, A E; Stegehuis, F

    1980-01-01

    A histochemical multi-step technique for the demonstration of phosphofructokinase activity in tissue sections is described. With this technique a semipermeable membrane is interposed between the incubating solution and the tissue sections preventing diffusion of the non-structurally bound enzyme into the medium during incubation. In the histochemical system the enzyme converts the substrate D-fructose-6-phosphate to D-fructose-1,6-diphosphate, which in turn is hydrolyzed by exogenous and endogenous fructose diphosphate aldolase to dihydroxyacetone phosphate and D-glyceral-dehyde-3-phosphate. The dihydroxyacetone phosphate is reversibly converted into D-glyceraldehyde-3-phosphate by exogenous and endogenous triosephosphate isomerase. Next the D-glyceraldehyde-3-phosphate is oxidized by exogenous and endogenous glyceraldehyde-3-phosphate dehydrogenase into 1,3-diphospho-D-glycerate. Concomitantly the electrons are transported via NAD+, phenazine methosulphate and menadione to nitro-BT. Sodium azide and amytal are incorporated to block electron transfer to the cytochromes. PMID:6446532

  7. Transcortical mixed aphasia due to cerebral infarction in left inferior frontal lobe and temporo-parietal lobe

    Energy Technology Data Exchange (ETDEWEB)

    Maeshima, S.; Matsumoto, T.; Ueyoshi, A. [Department of Physical Medicine and Rehabilitation, Wakayama Medical University, Wakayama (Japan); Toshiro, H.; Sekiguchi, E.; Okita, R.; Yamaga, H.; Ozaki, F.; Moriwaki, H. [Department of Neurological Surgery, Hidaka General Hospital, Wakayama (Japan); Roger, P. [School of Communication Sciences and Disorders, University of Sydney, Sydney, NSW (Australia)

    2002-02-01

    We present a case of transcortical mixed aphasia caused by a cerebral embolism. A 77-year-old right-handed man was admitted to our hospital with speech disturbance and a right hemianopia. His spontaneous speech was remarkably reduced, and object naming, word fluency, comprehension, reading and writing were all severely disturbed. However, repetition of phonemes and sentences and reading aloud were fully preserved. Although magnetic resonance imaging (MRI) showed cerebral infarcts in the left frontal and parieto-occipital lobe which included the inferior frontal gyrus and angular gyrus, single photon emission CT revealed a wider area of low perfusion over the entire left hemisphere except for part of the left perisylvian language areas. The amytal (Wada) test, which was performed via the left internal carotid artery, revealed that the left hemisphere was dominant for language. Hence, it appears that transcortical mixed aphasia may be caused by the isolation of perisylvian speech areas, even if there is a lesion in the inferior frontal gyrus, due to disconnection from surrounding areas. (orig.)

  8. Wada test for evaluation of language and memory function in medically intractable epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Yong Kook; Chung, Tae Sub; Suh, Jung Ho; Kim, Dong Ik; Kim, Eun Kyung; Lee, Byung In; Huh, Kyun [College of Medicine, Yonsei University, Seoul (Korea, Republic of)

    1992-05-15

    The Wada test was performed for lateralization of language and memory function, using intracarotid injection of Sodium Amytal. But the internal carotid artery (ICA) Wada test has some limitations for testing memory function. The posterior cerebral artery (PCA) Wada test has been designed to modify the ICA Wada test for testing memory function selectively. In our study, 10 patients out of 12 patients with intractable seizure underwent only the ICA Wada test and the other 2 patients underwent both the ICA and the selective PCA Wada test. In all 12 patients undergoing the ICA Wada test, we successfully localized speech and language dominance. Four of 12 patients who underwent the ICA Wada test for evaluation of memory function displayed superior memory functions in one hemisphere, but the other hemisphere also significantly contributed to memory. The selective PCA Wada test, performed in 2 patients, showed successful results of memory function test in both patients. Four of 12 patients underwent temporal lobectomy and there was no major post-operative language or memory deficits. We concluded that the ICA and PCA Wada tests are useful for preoperative evaluation of medically intractable epilepsy, and the PCA Wada test is valuable in memory evaluation in some patients who have high risk of postoperative global amnesia after temporal lobectomy following equivocal results of memory function by the ICA Wada test.

  9. Mitochondria mediate tumor necrosis factor-alpha/NF-kappaB signaling in skeletal muscle myotubes

    Science.gov (United States)

    Li, Y. P.; Atkins, C. M.; Sweatt, J. D.; Reid, M. B.; Hamilton, S. L. (Principal Investigator)

    1999-01-01

    Tumor necrosis factor-alpha (TNF-alpha) is implicated in muscle atrophy and weakness associated with a variety of chronic diseases. Recently, we reported that TNF-alpha directly induces muscle protein degradation in differentiated skeletal muscle myotubes, where it rapidly activates nuclear factor kappaB (NF-kappaB). We also have found that protein loss induced by TNF-alpha is NF-kappaB dependent. In the present study, we analyzed the signaling pathway by which TNF-alpha activates NF-kappaB in myotubes differentiated from C2C12 and rat primary myoblasts. We found that activation of NF-kappaB by TNF-alpha was blocked by rotenone or amytal, inhibitors of complex I of the mitochondrial respiratory chain. On the other hand, antimycin A, an inhibitor of complex III, enhanced TNF-alpha activation of NK-kappaB. These results suggest a key role of mitochondria-derived reactive oxygen species (ROS) in mediating NF-kappaB activation in muscle. In addition, we found that TNF-alpha stimulated protein kinase C (PKC) activity. However, other signal transduction mediators including ceramide, Ca2+, phospholipase A2 (PLA2), and nitric oxide (NO) do not appear to be involved in the activation of NF-kappaB.

  10. Developing a comprehensive presurgical functional MRI protocol for patients with intractable temporal lobe epilepsy: a pilot study

    International Nuclear Information System (INIS)

    Our aim was to put together and test a comprehensive functional MRI (fMRI) protocol which could compete with the intracarotid amytal (IAT) or Wada test for the localisation of language and memory function in patients with intractable temporal lobe epilepsy. The protocol was designed to be performed in under 1 h on a standard 1.5 tesla imager. We used five paradigms to test nine healthy right-handed subjects: complex scene-encoding, picture-naming, reading, word-generation and semantic-decision tasks. The combination of these tasks generated two activation maps related to memory in the mesial temporal lobes, and three language-related maps of activation in a major part of the known language network. The functional maps from the encoding and naming tasks showed typical and symmetrical posterior mesial temporal lobe activation related to memory in all subjects. Only four of nine subjects also showed symmetrical anterior hippocampal activation. Language lateralisation was best with the word generation and reading paradigms and proved possible in all subjects. The reading paradigm enables localisation of language function in the left anterior temporal pole and middle temporal gyrus, areas typically resected during epilepsy surgery. The combined results of this comprehensive f MRI protocol are adequate for a comparative study with the IAT in patients with epilepsy being assessed for surgery. (orig.)

  11. Changes in oscillatory dynamics in the cell cycle of early Xenopus laevis embryos.

    Directory of Open Access Journals (Sweden)

    Tony Y-C Tsai

    2014-02-01

    Full Text Available During the early development of Xenopus laevis embryos, the first mitotic cell cycle is long (∼85 min and the subsequent 11 cycles are short (∼30 min and clock-like. Here we address the question of how the Cdk1 cell cycle oscillator changes between these two modes of operation. We found that the change can be attributed to an alteration in the balance between Wee1/Myt1 and Cdc25. The change in balance converts a circuit that acts like a positive-plus-negative feedback oscillator, with spikes of Cdk1 activation, to one that acts like a negative-feedback-only oscillator, with a shorter period and smoothly varying Cdk1 activity. Shortening the first cycle, by treating embryos with the Wee1A/Myt1 inhibitor PD0166285, resulted in a dramatic reduction in embryo viability, and restoring the length of the first cycle in inhibitor-treated embryos with low doses of cycloheximide partially rescued viability. Computations with an experimentally parameterized mathematical model show that modest changes in the Wee1/Cdc25 ratio can account for the observed qualitative changes in the cell cycle. The high ratio in the first cycle allows the period to be long and tunable, and decreasing the ratio in the subsequent cycles allows the oscillator to run at a maximal speed. Thus, the embryo rewires its feedback regulation to meet two different developmental requirements during early development.

  12. Wada test for evaluation of language and memory function in medically intractable epilepsy

    International Nuclear Information System (INIS)

    The Wada test was performed for lateralization of language and memory function, using intracarotid injection of Sodium Amytal. But the internal carotid artery (ICA) Wada test has some limitations for testing memory function. The posterior cerebral artery (PCA) Wada test has been designed to modify the ICA Wada test for testing memory function selectively. In our study, 10 patients out of 12 patients with intractable seizure underwent only the ICA Wada test and the other 2 patients underwent both the ICA and the selective PCA Wada test. In all 12 patients undergoing the ICA Wada test, we successfully localized speech and language dominance. Four of 12 patients who underwent the ICA Wada test for evaluation of memory function displayed superior memory functions in one hemisphere, but the other hemisphere also significantly contributed to memory. The selective PCA Wada test, performed in 2 patients, showed successful results of memory function test in both patients. Four of 12 patients underwent temporal lobectomy and there was no major post-operative language or memory deficits. We concluded that the ICA and PCA Wada tests are useful for preoperative evaluation of medically intractable epilepsy, and the PCA Wada test is valuable in memory evaluation in some patients who have high risk of postoperative global amnesia after temporal lobectomy following equivocal results of memory function by the ICA Wada test

  13. Developing a comprehensive presurgical functional MRI protocol for patients with intractable temporal lobe epilepsy: a pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Deblaere, K.; Vandemaele, P.; Achten, E. [MRI Department -1 K12, Department of Radiology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent (Belgium); Backes, W.H.; Hofman, P.; Wilmink, J. [Department of Neuroradiology, University Hospital Maastricht, Postbus 5800, 6202 AZ Maastricht (Netherlands); Boon, P.A.; Vonck, K. [Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent (Belgium); Boon, P. [Department of Medical Psychology, University Hospital Maastricht (Netherlands); Troost, J. [Department of Neurology, University Hospital Maastricht (Netherlands); Vermeulen, J. [S.E.I.N Heemstede, Psychological Laboratory, Achterweg 5, 2103 SW Heemstede (Netherlands); Aldenkamp, A. [Epilepsy Center ' Kempenhaeghe' , Postbus 61, 5900 AB Heeze (Netherlands)

    2002-08-01

    Our aim was to put together and test a comprehensive functional MRI (fMRI) protocol which could compete with the intracarotid amytal (IAT) or Wada test for the localisation of language and memory function in patients with intractable temporal lobe epilepsy. The protocol was designed to be performed in under 1 h on a standard 1.5 tesla imager. We used five paradigms to test nine healthy right-handed subjects: complex scene-encoding, picture-naming, reading, word-generation and semantic-decision tasks. The combination of these tasks generated two activation maps related to memory in the mesial temporal lobes, and three language-related maps of activation in a major part of the known language network. The functional maps from the encoding and naming tasks showed typical and symmetrical posterior mesial temporal lobe activation related to memory in all subjects. Only four of nine subjects also showed symmetrical anterior hippocampal activation. Language lateralisation was best with the word generation and reading paradigms and proved possible in all subjects. The reading paradigm enables localisation of language function in the left anterior temporal pole and middle temporal gyrus, areas typically resected during epilepsy surgery. The combined results of this comprehensive f MRI protocol are adequate for a comparative study with the IAT in patients with epilepsy being assessed for surgery. (orig.)

  14. Interventional neuroradiology (surgical neuroanglography)

    International Nuclear Information System (INIS)

    The applications and effectiveness of surgical neuroangiography, or interventional neuroradiology of the head, neck, spine and brain are rapidly increasing. These procedures are used in the management of a variety of vascular lesions, either preoperatively or as the primary mode of treatment. Lesions that can be approached by the endovascular route, vascular neoplasms (benign or malignant), vasculas malformations (arterial, venous, or mixed), hemangiomas, arteriovenous fistulas, vessel lacerations, and extracranial or intracranial aneurysms are discussed, as are infusion chemotherapy and angioplasties of atherosclerotic or vasospastic extracranial or intracranial vessels. The various catheters or delivery systems and embolic agents, including conventional or special microcatheters, balloon catheters of various lumens, detachable balloons of silicone and latex, open-ended guide wires, and steerable microwires, as well as various embolic agents, either particulated or liquid, and including cytotoxic agents, are described. Functional vascular anatomy of the collateral circulation is reviewed, including extracerebral to intracerebral anastomases and the supply to the transcranial nerves. The use of chemical testing with Amytal and Xylocaine and electrophysiologic monitoring for safe embolization is demonstrated

  15. Whole-brain functional magnetic resonance imaging of cerebral arteriovenous malformations involving the motor pathways

    International Nuclear Information System (INIS)

    To investigate cortical, basal ganglia and cerebellar activation in patients with arteriovenous malformations (AVMs) involving the motor pathways, we studied ten patients (six male, four female, mean age 30.3 years, range 7.4-44.1) by whole-brain functional magnetic resonance imaging (fMRI) in a 1.5-T scanner with the EPI-BOLD-technique. In seven cases multiple fMRI studies were available, acquired in the course of the multi-session endovascular interventional treatment. Self-paced right- and left-handed finger-tapping tasks were used to invoke activation. In six patients a super-selective amytal test (Wada test) was performed during diagnostic pre-interventional angiography studies. Abnormal cortical activation patterns, with activation of the primary sensorimotor area, the supplementary motor area and/or the cerebellum shifted to unphysiological locations, were found in four patients. In all cases, localization of the AVM could account for the changes from the normal. After endovascular procedures, fMRI demonstrated shifts in the activation pattern in three patients. In the six patients that had undergone fMRI studies and the Wada test, both methods yielded comparable results. The fact that AVMs are structural anomalies for which the brain can partly compensate ('plasticity') was underlined by these results. fMRI is a valuable tool in the pre-therapeutic evaluation and post-interventional follow-up of patients with cerebral AVMs in whom an operation or an endovascular procedure is planned. (orig.)

  16. Successful management of a giant spinal arteriovenous malformation with multiple communications between primitive arterial and venous structures by embolization: report of a case.

    Science.gov (United States)

    Kuga, T; Esato, K; Zempo, N; Fujioka, K; Harada, M; Furutani, A; Akiyama, N; Toyota, S; Fujita, Y

    1996-01-01

    A 47-year-old woman was admitted to our hospital with a giant spinal arteriovenous malformation (AVM) causing heart failure and thoracic myelopathy. Angiography revealed that the spinal AVM had multiple feeding vessels branching from the 5th through 12th intercostal arteries. The drainage vein flowed to the azygos vein and superior vena cava. The AVM destroyed the 7th thoracic vertebra. The cardiac output was 16.7l/min and the shunt ratio was 64% before treatment. Embolization with cyanoacrylate was performed because the operation was considered to be associated with a significant risk of paraplegia and organ ischemia. The cardiac output decreased to 11.6l/min and the shunt ratio was reduced to 32%. After embolization the patient demonstrated no symptoms of either heart failure or sensory deficits. During embolization, provocative tests using sodium amytal and lidocaine with magnetic stimulation were also performed. The above findings suggest that provocative tests and magnetic stimulation are useful to predict paraplegia, which could result from embolization while, in addition, embolization is considered to be a useful treatment for multiple shunt and nidus in this region. PMID:8883257

  17. Generation of reducing power in chemosynthesis. 3. Energy-linked reduction of pyridine nucleotides in Thiobacillus novellus.

    Science.gov (United States)

    Aleem, M I

    1966-02-01

    Aleem, M. I. H. (Research Institute for Advanced Studies, Baltimore, Md.). Generation of reducing power in chemosynthesis. III. Energy-linked reduction of pyridine nucleotides in Thiobacillus novellus. J. Bacteriol. 91:729-736. 1966.-Cell-free extracts from Thiobacillus novellus. catalyzed an adenosine triphosphate (ATP)-dependent reduction of pyridine nucleotides anaerobically, or aerobically when the respiratory chain was inhibited by azide. The exogenous electron donor employed for the reduction of nicotinamide adenine dinucleotide or nicotinamide adenine dinucleotide phosphate (NADP) was thiosulfate, formate, or mammalian ferrocytochrome c. In the latter case, the oxidation of ferrocytochrome c was observed with the concomitant reduction of the pyridine nucleotide. Values calculated for the molar ratios of ATP utilized-NADP reduced and of cytochrome c oxidized-NADP reduced were 1:1 and 2:1, respectively. The energy-dependent reduction of the pyridine nucleotides was inhibited by Atabrine or amytal and by low concentrations of the uncouplers of oxidative phosphorylation such as 2,4-dinitrophenol and carbonyl cyanide m-chlorophenyl hydrazone. Evidence is presented showing that the reduced pyridine nucleotides are essential for providing the reducing power for the energy-dependent reduction of carbon dioxide in T. novellus. PMID:4379907

  18. Transcortical mixed aphasia due to cerebral infarction in left inferior frontal lobe and temporo-parietal lobe

    International Nuclear Information System (INIS)

    We present a case of transcortical mixed aphasia caused by a cerebral embolism. A 77-year-old right-handed man was admitted to our hospital with speech disturbance and a right hemianopia. His spontaneous speech was remarkably reduced, and object naming, word fluency, comprehension, reading and writing were all severely disturbed. However, repetition of phonemes and sentences and reading aloud were fully preserved. Although magnetic resonance imaging (MRI) showed cerebral infarcts in the left frontal and parieto-occipital lobe which included the inferior frontal gyrus and angular gyrus, single photon emission CT revealed a wider area of low perfusion over the entire left hemisphere except for part of the left perisylvian language areas. The amytal (Wada) test, which was performed via the left internal carotid artery, revealed that the left hemisphere was dominant for language. Hence, it appears that transcortical mixed aphasia may be caused by the isolation of perisylvian speech areas, even if there is a lesion in the inferior frontal gyrus, due to disconnection from surrounding areas. (orig.)

  19. Unilateral mesial temporal atrophy after a systemic insult as a possible etiology of refractory temporal lobe epilepsy: case report Esclerose mesial temporal unilateral após insulto sistêmico como possível etiologia de epilepsia refratária do lobo temporal: relato de caso

    Directory of Open Access Journals (Sweden)

    Arthur Cukiert

    1997-09-01

    Full Text Available Mesial temporal sclerosis is the main pathological substrate present in refractory temporal lobe epilepsy and its presence is often related to the occurrence of febrile seizures in infancy. There is an on-going discussion on the nature of mesial temporal sclerosis as it related to epilepsy: cause or consequence. A previously normal child developed hyperosmolar coma after abdominal surgery at the age of 6. Three months afterwards he developed simple and complex partial seizures with an increasing frequency and refractory to multiple mono-and polytherapic drug regimens. He was evaluated for surgery at the age of 13. Ictal and interictal recordings showed left temporal lobe abnormalities. Early CT scaning suggested left temporal atrophy. MRI showed mesial temporal sclerosis. Neuropsichological testing showed verbal memory deficits and he passed a left carotid artery amytal injection. He was submitted to a cortico-amygdalo-hippocampectomy and has been seizure-free since then. The clinical data obtained from this patient suggest that at least in this case mesial temporal sclerosis would be related to the cause of epilepsy and not resultant from repeated seizure activity.A esclerose mesial temporal é o principal substrato anatomo-patológico envolvido na epilepsia refratária do lobo temporal e está frequentemente associada à ocorrência de convulsões febris na infância. Persiste até o momento intensa discussão se a esclerose mesial seria causa ou consequência da síndrome epiléptica. Uma criança previamente normal, desenvolveu coma hiperosmolar após intercorrência em cirurgia abdominal aos 6 anos de idade. Após 3 meses iniciaram-se crises parciais simples e complexas em frequência ascendente e refratárias a múltiplos esquemas terapêuticos em mono- e politerapia. Ele realizou investigação pré-operatória para epilepsia aos 13 anos de idade. Registros eletrencefalográficos de superfície ictais e interictais mostraram anormalidades

  20. The Role of Investigative Modalities in Epilepsy Work-up

    Directory of Open Access Journals (Sweden)

    Helen Nayeri

    2009-01-01

    epilepsy. In such patients, there is an approximately 97% satisfactory post-operative outcome. In cases with discordant EEG and MR findings or when confirmation of the epileptogenicity of the MR-identified lesion is lacking, intracranial EEG recording using subdural or parenchymal depth electrodes are warranted. Invasive electrophysiological studies are also indicated in cases with more than one MR abnormality, when MR shows a large atrophic region or developmental abnormality, and when functional mapping of the brain is indicated based on MR findings or other reasons. "nOther modalities for preoperative evaluation of surgical candidates with intractable epilepsy involve functional neuroimaging (include SPECT, PET, magnetoencephalography as well as neuropsychological assessment and lateralization of language and memory functions by Amytal procedure (IAP or Wada test. "nMR imaging protocols for epilepsy vary. The protocol must be able to detect hippocampal sclerosis, as well as foreign tissue lesions (i.e., neoplasms, infections, etc and developmental abnormalities. The MR imaging of amygdala and hippocampus is best performed in a slightly oblique coronal plane, perpendicular to the long axis of hippocampus. The study requires evaluation of both morphological and signal abnormalities. High resolution FSE T2W and IR sequences are important for depiction of hippocampal signal and architectural changes. Either a coronal T1W gradient volume acquisition (e.g., SPGR or MP-RAGE sequences or inversion recovery (IR can be used to help evaluate cortical dysplasia, as well as to assess subtle hippocampal asymmetry. High-resolution T2 and axial inversion recovery FSE imaging is also routinely used. Coronal, T1-weighted, three dimensional volume, gradient echo sequences not only provide excellent gray-white matter differentiation, but also thin slices (1.0 to 1.6 mm thick, which may improve the detection of subtle malformations of cortical development. Volume loss and T2 signal changes