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1.
J Neuroradiol ; 48(4): 271-276, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31034897

RESUMO

PURPOSE: Characterize and determine the frequency of dissections of the supra-aortic arteries (SAA) and injuries to the cervical spine and pharyngolaryngeal cartilages viewed on CT scans after an attempted suicide by hanging. MATERIALS AND METHODS: A retrospective, single-centre study of all patients admitted for attempted suicide by hanging between January 2010 and June 2017 who received CT angiography of the SAA. Search for signs of dissection of the cervical arteries and injuries to the brain, spinal column and pharyngeal and laryngeal cartilages. The results were compared with the initial clinical severity, which was assessed indirectly by whether patients were initially admitted in an intensive care unit (ICU) or in an emergency department (ED). RESULTS: Out of 162 patients included, 4 presented with SAA dissection (2.5%), comprising 3 vertebral arteries and 1 external carotid artery. The cases in question were of 4 men, all in cardiac arrest on arrival and all were treated in ICU. Of the most serious cases, 18/72 (25%) had anoxia-related injuries and one also presented with a C2 fracture. No vascular lesions or signs of cerebral anoxia were observed in the 90 ED patients. Nevertheless, pharyngeal and laryngeal fractures were observed in both groups, with no significant difference. CONCLUSION: In our study, 2.5% of CT angiograms performed after an attempted hanging revealed SAA dissection. Crucially, only most severe patients, who have been immediately admitted to ICU suffered SAA. These results call into question the systematic indication of this exam in cases of hanging attempts.


Assuntos
Lesões do Pescoço , Tentativa de Suicídio , Artérias , Angiografia por Tomografia Computadorizada , Humanos , Masculino , Estudos Retrospectivos
2.
Eur Radiol ; 26(11): 4194-4203, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26843012

RESUMO

OBJECTIVE: To identify relevant relative cerebral blood volume biomarkers from T2* dynamic-susceptibility contrast magnetic resonance imaging to anticipate glioblastoma progression after chemoradiation. METHODS: Twenty-five patients from a prospective study with glioblastoma, primarily treated by chemoradiation, were included. According to the last follow-up MRI confirmed status, patients were divided into: relapse group (n = 13) and control group (n = 12). The time of last MR acquisition was tend; MR acquisitions performed at tend-2M, tend-4M and tend-6M (respectively 2, 4 and 6 months before tend) were analyzed to extract relevant variations among eleven perfusion biomarkers (B). These variations were assessed through R(B), as the absolute value of the ratio between ∆B from tend-4M to tend-2M and ∆B from tend-6M to tend-4M. The optimal cut-off for R(B) was determined using receiver-operating-characteristic curve analysis. RESULTS: The fraction of hypoperfused tumor volume (F_hPg) was a relevant biomarker. A ratio R(F_hPg) ≥ 0.61 would have been able to anticipate relapse at the next follow-up with a sensitivity/specificity/accuracy of 92.3 %/63.6 %/79.2 %. High R(F_hPg) (≥0.61) was associated with more relapse at tend compared to low R(F_hPg) (75 % vs 12.5 %, p = 0.008). CONCLUSION: Iterative analysis of F_hPg from consecutive examinations could provide surrogate markers to predict progression at the next follow-up. KEY POINTS: • Related rCBV biomarkers from DSC were assessed to anticipate GBM progression. • Biomarkers were assessed through their patterns of variation during the follow-up. • The fraction of hypoperfused tumour volume (F_hP g ) seemed to be a relevant biomarker. • An innovative ratio R(F_hP g ) could be an early surrogate marker of relapse. • A significant time gain could be achieved in the management of GBM patients.


Assuntos
Biomarcadores/metabolismo , Neoplasias Encefálicas/terapia , Quimiorradioterapia/métodos , Glioblastoma/terapia , Adulto , Idoso , Volume Sanguíneo , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/fisiopatologia , Meios de Contraste , Progressão da Doença , Feminino , Glioblastoma/patologia , Glioblastoma/fisiopatologia , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Estudos Prospectivos , Curva ROC
3.
AJNR Am J Neuroradiol ; 34(1): 185-90, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22678847

RESUMO

BACKGROUND AND PURPOSE: Patterns of DWI findings that predict recurrent ischemic events after TIA are well-established, but similar assessments of intracranial MRA findings are not available. We sought to determine the imaging characteristics of MRA that are predictive of early recurrent stroke/TIA in patients with TIA. MATERIALS AND METHODS: We performed a retrospective analysis of 129 consecutive patients with a clinical diagnosis of TIA in whom MR imaging was done within 24 hours of symptom onset. We calculated the sensitivity, specificity, positive predictive value, and negative predictive value of >50% stenosis or occlusion of symptomatic intracranial arteries for recurrent stroke/TIA at 7 days after TIA. We used logistic regression analysis to adjust for the clinical ABCD(2) score. We performed this analysis for symptomatic steno-occlusive lesions at any site and symptomatic steno-occlusive lesions on proximal large intracranial arteries (internal carotid artery, vertebral artery, basilar artery, and circle of Willis). RESULTS: Forty-two (32.5%) patients had acute ischemic lesions on DWI; 16 (12.4%) had significant MRA lesions, of which 11 (8.5%) were on proximal vessels. Nine patients had early recurrence (TIA, 7; minor stroke, 2). Only patients with proximal MRA lesions were at higher risk of early recurrence independent of the ABCD(2) score (adjusted odds ratio, 5.5; 95% confidence interval, 1.1-27.8; P = .04). CONCLUSIONS: Proximal lesions of cerebral arteries seen on MRA were predictive of recurrent stroke/TIA at 7 days. These findings suggest that MRA could be used to improve the selection of patients with TIA at high risk of early recurrent stroke/TIA.


Assuntos
Doenças Arteriais Intracranianas/diagnóstico , Doenças Arteriais Intracranianas/epidemiologia , Ataque Isquêmico Transitório/diagnóstico , Ataque Isquêmico Transitório/epidemiologia , Angiografia por Ressonância Magnética/estatística & dados numéricos , Idoso , Comorbidade , Constrição Patológica/diagnóstico , Constrição Patológica/epidemiologia , Feminino , França/epidemiologia , Humanos , Incidência , Pessoa de Meia-Idade , Prognóstico , Recidiva , Fatores de Risco
4.
J Neuroradiol ; 37(1): 68-71, 2010 Mar.
Artigo em Francês | MEDLINE | ID: mdl-19665792

RESUMO

We report an atypical case of cerebral toxoplasmosis (CT) in a 70-year-old woman with a history of breast cancer. Contrast-enhanced computed tomography revealed a single ring-enhancing lesion in the pons with perifocal oedema and mass effect. Toxoplasma encephalitis was suggested by means of diffusion weighted imaging, MR perfusion and MR spectroscopy, leading to the discovery of HIV infection. The patient was put on antitoxoplasma therapy. Subsequent clinical and radiological improvements confirmed the diagnosis.


Assuntos
Encéfalo/patologia , Angiografia por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Toxoplasmose Cerebral/diagnóstico , Idoso , Feminino , Humanos
5.
Rev Neurol (Paris) ; 165(8-9): 709-17, 2009.
Artigo em Francês | MEDLINE | ID: mdl-19147166

RESUMO

BACKGROUND AND PURPOSE: Moyamoya disease is rare among non-Asian populations and its clinical features are ill-defined. We report 12 new cases of Moyamoya disease in French, non-Asian adults. METHODS: We identified adults with Moyamoya disease managed at a French University Hospital from 1998 through 2006. We reviewed baseline clinical and radiological data and collected follow-up data between March and June 2008. The risk of recurrent stroke was determined using the Kaplan-Meier method. RESULTS: Twelve patients, 10 women and two men, were included. The mean age at baseline was 31.1 years. The initial clinical manifestation was ischemic stroke in 10 patients. The disease was clinically asymptomatic in two patients. The mean follow-up in the 10 symptomatic patients was 52.4 months. Only one patient was surgically treated. The one and five-year risk of recurrent stroke were both 50%. At the end of the follow-up, one patient was dead, four patients had no functional impairment (grade 0-1 on the Rankin scale), and seven patients had moderate functional impairment (grade 2-3 on the Rankin scale). A cognitive dysfunction as identified by failure on the Trail Making Test part B was found in six of ten patients evaluated. CONCLUSION: Moyamoya disease in this cohort of French, non-Asian adults was associated with high rates of both recurrent stroke and cognitive impairment. The findings suggest that Moyamoya disease in non-Asian adults is a potentially severe disease.


Assuntos
Doença de Moyamoya/patologia , Adolescente , Adulto , Angiografia Cerebral , Circulação Cerebrovascular , Progressão da Doença , Feminino , França , Humanos , Estimativa de Kaplan-Meier , Angiografia por Ressonância Magnética , Masculino , Doença de Moyamoya/diagnóstico , Doença de Moyamoya/diagnóstico por imagem , Testes Neuropsicológicos , Recidiva , Acidente Vascular Cerebral/etiologia , Adulto Jovem
6.
J Neuroradiol ; 33(4): 263-5, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17041532

RESUMO

We report the case of a patient with bilateral and symmetrical T2 hyperintensities of the middle cerebellar peduncles. She had a history of left pontine infarction 8 months before. This was attributed to bilateral Wallerian degeneration. MR Spectroscopy showed decreased N-acetyl aspartate/Creatine (NAA/Cr) ratio in the cerebellar peduncles as well as in the whole cerebellum. We hypothesize that this could reflect neuronal degeneration following a stroke.


Assuntos
Infartos do Tronco Encefálico/complicações , Ângulo Cerebelopontino , Mesencéfalo , Degeneração Walleriana/etiologia , Idoso , Feminino , Humanos
7.
J Neuroradiol ; 33(3): 201-5, 2006 Jun.
Artigo em Francês | MEDLINE | ID: mdl-16840964

RESUMO

The authors report a case of an X-linked-adrenoleukodystrophy (ALD) in a young adult presenting with hemianopsia. Adult onset cerebral ALD is rare and represents only 3% of cases of ALD. The observation describes clinical data, as well as conventional and spectroscopic MR imaging and related value in prognosis evaluation.


Assuntos
Adrenoleucodistrofia/diagnóstico , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Adulto , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Colina/metabolismo , Diagnóstico Diferencial , Humanos , Masculino
8.
J Radiol ; 86(9 Pt 2): 1091-101, 2005 Sep.
Artigo em Francês | MEDLINE | ID: mdl-16227905

RESUMO

Imaging of stroke has evolved with the development of stroke units and the CE approval of intravenous thrombolysis in the first three hours after stroke onset. The goal of imaging in the acute phase of stroke is: to make the diagnosis of stroke; to rule out other diagnosis (above all hemorrhagic strokes); to precise the location of the arterial occlusion; to assess the level of hypoperfusion; to evaluate the viability and reversibility of brain lesions; to understand the origin of the stroke by evaluating cervical arteries. Constraints of imaging in the acute phase of stroke are: the need to be performed as fast as possible to not delay IV thrombolysis (time is brain); machines must be available 24 hours a day, 7 days a week as close as possible to the stroke unit. The aim of imaging are: in routine practice to evaluate the likely benefits (provided by penumbra imaging) and risks of IV thrombolysis; in term of "evidence based medicine" to better evaluate new specific stroke therapies in randomized studies (IV thrombolysis between 3 to 4 hours, use of anti GpIIbIIIa, intra-arterial mechanical or chemical thrombolysis...). Magnetic resonance imaging is considered the goal standard of stroke imaging allowing to evaluate in a "one stop shopping" the level of arterial occlusion, hypoperfusion and brain viability. However, stroke management is a regional issue and performing MR in extreme emergency is almost impossible in all stroke units outside or even within university hospitals 24 hours a day. CT-perfusion and CT angiography are therefore an accurate alternative tool for acute stroke imaging. Multislice CT is indeed available in almost all stroke units. The examination is very time-saving and clinically relevant to make the decision for IV thrombolysis.


Assuntos
Isquemia Encefálica/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Isquemia Encefálica/tratamento farmacológico , Angiografia Cerebral/métodos , Infarto Cerebral/diagnóstico por imagem , Infarto Cerebral/tratamento farmacológico , Circulação Cerebrovascular/fisiologia , Tomada de Decisões , Feminino , Fibrinolíticos/uso terapêutico , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/uso terapêutico , Fatores de Risco , Terapia Trombolítica , Fatores de Tempo , Sobrevivência de Tecidos/fisiologia , Resultado do Tratamento
9.
J Radiol ; 85(11): 1943-6, 2004 Nov.
Artigo em Francês | MEDLINE | ID: mdl-15602417

RESUMO

Cervicothoracic syringomyelia is a frequent feature in Chiari I malformation. It can be symptomatic or not, and is well demonstrated by magnetic resonance imaging (MRI). Its spontaneous resolution is uncommon. The authors report a case of spontaneous resolution of a thoracic syrinx in an 18-year-old patient with a Chiari I malformation. MRI study performed 6 years previously because of worsening headaches demonstrated a Chiari I malformation associated with a syrinx cavity. The cavity disappearance was noted after improvement of the symptoms.


Assuntos
Malformação de Arnold-Chiari/complicações , Siringomielia/etiologia , Adolescente , Criança , Feminino , Seguimentos , Humanos , Remissão Espontânea
10.
Neuroradiology ; 45(11): 812-7, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14517703

RESUMO

Inflammatory myofibroblastic tumours (IMT), also called inflammatory pseudotumours, nodular lymphoid hyperplasia, plasma-cell granuloma and fibrous xanthoma, are rare soft-tissue lesions characterised by inflammatory cells and a fibrous stroma. Clinically and radiologically, they may look like malignant tumours. They rarely affect the central nervous system and are very rare in the spinal cord. We report an IMT of the spinal cord in a 22-year-old woman presenting with spinal cord compression and a cauda equina syndrome. MRI showed a lesion at T9 with extramedullary and intramedullary components giving low signal on T2-weighted images and enhancing homogeneously. Pial lesions on the lumbar enlargement and thoracic spinal were present 11 months after surgery, when the lesion recurred. We present the radiological, operative and pathological findings and review the literature.


Assuntos
Granuloma de Células Plasmáticas , Imageamento por Ressonância Magnética , Doenças da Medula Espinal , Adulto , Cauda Equina , Feminino , Granuloma de Células Plasmáticas/complicações , Granuloma de Células Plasmáticas/epidemiologia , Granuloma de Células Plasmáticas/patologia , Granuloma de Células Plasmáticas/cirurgia , Humanos , Síndromes de Compressão Nervosa/etiologia , Recidiva , Reoperação , Doenças da Medula Espinal/complicações , Doenças da Medula Espinal/epidemiologia , Doenças da Medula Espinal/patologia , Doenças da Medula Espinal/cirurgia
11.
J Radiol ; 83(12 Pt 1): 1850-2, 2002 Dec.
Artigo em Francês | MEDLINE | ID: mdl-12511842

RESUMO

Superficial siderosis of the central nervous system is secondary to chronic subarachnoid bleeding. However, the underlying etiology is not always detected. Superficial siderosis can be diagnosed at MRI by the presence of a hypointense rim along the brain surface on gradient echo T2W images. The authors report a case of superficial cerebral siderosis where the underlying etiology remained undiagnosed in spite of extensive neuroradiological work up.


Assuntos
Doenças do Sistema Nervoso Central/diagnóstico , Imageamento por Ressonância Magnética/métodos , Siderose/diagnóstico , Doenças do Sistema Nervoso Central/tratamento farmacológico , Doenças do Sistema Nervoso Central/etiologia , Angiografia Cerebral , Quelantes/uso terapêutico , Doença Crônica , Feminino , Perda Auditiva Bilateral/etiologia , Humanos , Pessoa de Meia-Idade , Siderose/tratamento farmacológico , Siderose/etiologia , Hemorragia Subaracnóidea/complicações , Trientina/uso terapêutico
12.
Neuroradiology ; 43(6): 485-8, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11465762

RESUMO

We report a case of Lyme myelitis in a 31-year-old man, presenting with a conus medullaris syndrome. MRI demonstrated contrast enhancement on the pial surface of the lower thoracic cord and conus medullaris. Elevated blood immunoglobulins and IgM antibodies against Borrelia burgdorferi in the cerebrospinal fluid (CSF) were found. Leptomeningitis may be the first stage of spinal infection in Lyme disease, preceding parenchymal infection leading to myelitis. Vasculitis is probably the major mechanism. MRI findings are nonspecific and the diagnosis is given by serum and CSF analyses. Early treatment with antibiotics and high doses steroids may result in complete recovery, as in this case.


Assuntos
Borrelia burgdorferi/isolamento & purificação , Doença de Lyme/patologia , Mielite/etiologia , Mielite/patologia , Adulto , Borrelia burgdorferi/patogenicidade , Diagnóstico Diferencial , Humanos , Imunoglobulina M/análise , Doença de Lyme/diagnóstico , Imageamento por Ressonância Magnética , Masculino , Testes Sorológicos
13.
Radiology ; 216(2): 351-5, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10924552

RESUMO

PURPOSE: To investigate and characterize the global distribution of magnetization transfer (MT) ratio values of normal-appearing white matter (NAWM) in patients with relapsing-remitting multiple sclerosis (MS) and test the hypothesis that the MT histogram for NAWM reflects disease progression. MATERIALS AND METHODS: Conventional and MT magnetic resonance (MR) images were obtained in 23 patients and 25 healthy volunteers. Clinical tests for comparison with the MT histogram parameters included the Extended Disability Status Scale and the ambulation index. Lesion load calculated with T2-weighted MR images and whole-brain and white matter volumes were measured. RESULTS: The location of the MT histogram peak and the mean MT ratio for NAWM were significantly lower in patients with MS than in control subjects. In longitudinal studies, the histogram peak location and mean MT ratio shifted in the direction of normal values as the duration of disease increased. A mean of 26.5% of the volume of new lesions identified on the later studies were demonstrated to have originated in NAWM corresponding to "lost" pixels on the histogram. CONCLUSION: MT histogram analysis of NAWM, including longitudinal analysis, may provide new prognostic information regarding lesion formation and increase understanding of the course of the disease.


Assuntos
Encéfalo/patologia , Imageamento por Ressonância Magnética/métodos , Esclerose Múltipla Recidivante-Remitente/patologia , Adulto , Pessoas com Deficiência/classificação , Progressão da Doença , Feminino , Seguimentos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Estudos Longitudinais , Masculino , Esclerose Múltipla Recidivante-Remitente/diagnóstico , Esclerose Múltipla Recidivante-Remitente/fisiopatologia , Exame Neurológico , Prognóstico , Valores de Referência , Caminhada/fisiologia
14.
Neurology ; 54(1): 15-9, 2000 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-10636119

RESUMO

OBJECTIVE: To quantitate the extent of neuronal cell loss in MS via the whole brain's N-acetylaspartate (NAA) concentration (WBNAA). METHODS: Because NAA is assumed to be present only in neuronal cell bodies and their axons, we measured WBNAA as a marker for viable neurons in 12 patients (9 women and 3 men, 26 to 53 years of age) suffering from relapsing-remitting (RR) MS for at least 5 years and compared them with 13 age- and sex-matched normal controls. Total brain NAA was determined with proton MR spectroscopy, and WBNAA was obtained by dividing it by the total brain volume, calculated from high resolution MRI. RESULTS: The WBNAA of the RR MS patients was lower than their matched controls (p<0.005). This difference was greater among older than younger subjects. The linear prediction equations of WBNAA with age indicate a faster, x10, decline in the patients, approximately 0.8% per year of age (p = 0.022). CONCLUSION: The age-dependent decrease of whole brain N-acetylaspartate (WBNAA) in the patients suggests that progressive neuronal cell loss is a cardinal feature of this disease. WBNAA offers a quick, highly reproducible measure of disease progression and may be an important marker of treatment efficacy in MS as well as other neurodegenerative diseases.


Assuntos
Ácido Aspártico/análogos & derivados , Encéfalo/metabolismo , Esclerose Múltipla/metabolismo , Adolescente , Adulto , Ácido Aspártico/metabolismo , Biomarcadores , Sobrevivência Celular , Progressão da Doença , Feminino , Humanos , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/fisiopatologia , Neurônios/metabolismo , Neurônios/fisiologia , Valores de Referência , Reprodutibilidade dos Testes , Índice de Gravidade de Doença
15.
AJNR Am J Neuroradiol ; 20(9): 1613-8, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10543630

RESUMO

BACKGROUND AND PURPOSE: Multiple sclerosis (MS) is the most common inflammatory disease of the central nervous system and manifests both physical and neurocognitive disabilities. Although predominantly a disease of the white matter, MS is also characterized by lesions in the gray matter. Previous pathologic studies have found that cortical and deep gray matter lesions comprised 5% and 4%, respectively, of total lesions. Using software for lesion detection and quantitation, our study was designed to determine MS involvement in the cortical and deep gray matter and to correlate gray matter lesion load with neurocognitive function and the Kurtzke Expanded Disability Status Scale. METHODS: Using a semiautomated segmentation algorithm that detected and delineated all possible brain MS lesions on MR images, we investigated gray matter lesion volume in 18 patients with untreated relapsing-remitting MS. Cortical and deep gray matter lesions then were correlated with the neurocognitive and physical disability measurements. RESULTS: We found that cortical gray matter lesions comprised approximately 5.7% of the total lesion volume, whereas deep gray matter lesions comprised another 4.6% in this patient cohort. No strong correlations were found between gray matter lesions and disability status or neurocognitive function. CONCLUSION: These results are similar to those found in previous pathologic studies. The cortical lesion load in cases of relapsing-remitting MS, as measured by MR imaging, represents less than 6% of the total lesion volume and does not correlate with disability measures or neurocognitive tests.


Assuntos
Córtex Cerebral/patologia , Avaliação da Deficiência , Imageamento por Ressonância Magnética , Esclerose Múltipla Recidivante-Remitente/diagnóstico , Testes Neuropsicológicos , Adulto , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes
17.
Magn Reson Med ; 40(5): 684-9, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9797150

RESUMO

The intra-individual and inter-individual variations of the global N-acetylaspartate (NAA) concentration were measured in a cohort of five 42+/-5 year-old normal females. The total NAA signal from the whole head was obtained with non-localized non-echo proton spectroscopy (1H-MRS) and converted into absolute mole amounts using phantom replacement. Since NAA is assumed to be present only in neurons, its concentration was obtained by dividing these mole amounts with the brains' volume, calculated from high resolution MRI. The key feature of the procedure is its near-complete suppression of the intense subcutaneous and bone marrow lipids' signals, whose chemical shifts neighbor and underlay the NAA. This was achieved by exploiting the lipids' much shorter T1s, compared to that of NAA, for destructive interference of their signals in co-addition following alternating, nonselective 180 degrees inversions. The average global, inter-individual NAA concentration in that group was found to be 10.63 mM with a 95% confidence interval of 10.43-10.82 mM.


Assuntos
Ácido Aspártico/análogos & derivados , Encéfalo/metabolismo , Espectroscopia de Ressonância Magnética , Adulto , Fatores Etários , Análise de Variância , Ácido Aspártico/análise , Química Encefálica , Estudos de Coortes , Feminino , Humanos , Pessoa de Meia-Idade , Prótons , Valores de Referência , Reprodutibilidade dos Testes
18.
Neurochirurgie ; 42(3): 153-61, 1996.
Artigo em Francês | MEDLINE | ID: mdl-9084742

RESUMO

Inactivation of an epileptogenic focus by dividing it into sub-unities unable to maintain epileptic activity has been demonstrated in animals. Based on these experiments, multiple subpial transections have been performed in patients suffering from partial drug-resistant epilepsies when resection of the epileptogenic cortex was not possible. In order to develop a new surgical technique for such epilepsies, the authors present an initial study of multiple cortical laser photolesions on the rabbit brain. The aim of this study is to assess the histological lesions created on the cortex with a laser at a chronic stage, and to compare the electrical paroxysmal activity of a penicillin focus on the laser irradiated cortex and on the non radiated cortex in the same animal. Twenty-five adult albino rabbits were used for this study. Both hemispheres of 19 rabbits have been exposed; 14 to 35 photolesions in a network were performed on one hemisphere using a 1.064 microns wavelength Nd-YAG laser. Six to twenty-one days later, a penicillin-induced focus was created on both hemispheres, a corticographic study was performed, and each animal was sacrificed for histological study of the brain. For the 6 last animals a high-power 0.805 micron wavelength diode laser was used with the same protocol. Histological study was solely performed in order to compare the effects of both lasers. In 11 animals electrocorticographic control was reliable. Time to first spike occurrence after penicillin application was significantly increased on the treated hemisphere as compared to the untreated one (1' to 14'30" and 10" to 6', respectively; p < 0.01) and the number of spikes per minute at early and late counts was significantly smaller on the treated hemisphere as compared to the untreated one (1 to 29 and 2 to 70, respectively; p < 0.02). Histologically the lesions appeared as cone-shaped coagulation necrosis surrounded by an area of macrophagic reaction, angiogenesis and gliosis. With the diode laser, some lesions included ischemic changes extended in the white matter. This study demonstrated the possibility of creating limited and reproducible photolesions using the laser light energy, without extensive destruction of the cortex. These lesions were reaching from one third to the totality of the cortical depth, depending on laser exposure parameters. This study also demonstrated that these photolesions arranged in a network and at a chronic stage were associated with a significantly reduced paroxysmal activity of a penicillin focus when compared to intact cortex. Since such lesions did not totally isolate cortical sub-unities, spiking was still recorded from the irradiated cortex, but at a lower rate, suggesting a disorganization of the local neuronal network responsible for paroxysmal activity.


Assuntos
Córtex Cerebral/efeitos da radiação , Epilepsia/fisiopatologia , Lasers , Animais , Córtex Cerebral/patologia , Córtex Cerebral/cirurgia , Modelos Animais de Doenças , Eletroencefalografia , Epilepsia/patologia , Epilepsia/cirurgia , Fotocoagulação a Laser/métodos , Penicilinas , Coelhos
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