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Functional significance of MRI defined mesial temporal sclerosis in temporal lobe epilepsy

Significado funcional da esclerose mesial temporal definida por ressonância magnética em epilepsia do lobo temporal

Abstracts

The functional significance of MRI-defined mesial temporal sclerosis in temporal lobe epilepsy (TLE) is not completely established. In order to study the possible relationship between signals of mesial temporal sclerosis on MRI and interictal SPECT findings we selected 18 patients with complex partial seizures, unilateral temporal EEG focus and normal CT. The EEG focus was defined by the presence of interictal sharp waves and slow background on several scalp EEG obtained during many years of follow up in all patients and by ictal recordings with sphenoidal electrodes in 12 patients. Group I comprised patients (n=11) in whom MRI showed mesial temporal sclerosis; group II patients (n=7) had normal MRIs. All patients were submitted to interictal 99m-Tc HMPAO injections with concomitant EEG monitoring. Lateralized hypoperfusion ipsilateral to the EEG was found in 13 patients (72%). In all Group II and in 6 Group I patients a temporal hypoperfusion was found. This SPECT study showed a higher positivity rate in patients with normal MRI than previously reported. On the other hand, in all these group II patients a neocortical origin of epileptic focus was suspected on clinical or electroencephalographic basis. Positive SPECT findings may be at least as prevalent in neocortical as in mesiolimbic epilepsy.

epilepsy; temporal lobe epilepsy; SPECT; MRI


O significado funcional dos sinais de esclerose mesial temporal observados em ressonância magnética ainda não está estabelecido. Para estudar as relações entre sinais de esclerose mesial temporal na ressonância magnética e alterações no SPECT intercrítico, foram selecionados 18 pacientes com epilepsia do lobo temporal cujo diagnóstico foi definido pela presença de descargas de ondas agudas e alentecimento da atividade de base em vários EEG obtidos durante vários anos de seguimento em todos os pacientes e por registros críticos com eletrodos esfenoidais em 12 pacientes. No grupo I foram incluídos pacientes (n=11) com sinais de esclerose mesial temporal na ressonância magnética; no grupo II (n=7), pacientes com ressonância normal. Em todos os casos a injeção do Tc 99 HMPAO foi realizada no período intercrítico com monitorização EEG. Foi observada hipoperfusão lateralizada ipsolateral ao foco definido pelo EEG em 13 pacientes (72%). Todos os pacientes do grupo II e 6 pacientes do grupo I tiveram hipoperfusão temporal. Este estudo mostrou maior positividade de SPECT em pacientes com ressonância magnética normal do que tem sido referido na literatura. Como os pacientes do grupo II tinham sinais clínicos ou eletrencefalográficos sugestivos de origem neocortical de suas crises epilépticas, postulamos que hipoperfusão em estudos de SPECT pode ser demonstrada tanto em epilepsia temporal neocortical como mesiolímbica.

epilepsia; epilepsia temporal; SPECT; ressonância magnética


Functional significance of MRI defined mesial temporal sclerosis in temporal lobe epilepsy

Significado funcional da esclerose mesial temporal definida por ressonância magnética em epilepsia do lobo temporal

Elza Márcia T. YacubianI; Arthur CukiertI; Paulo CarrilhoI; Carmen Lisa JorgeI; Lia Arno FioreI; Carlos Alberto BuchpiguelII

IHospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo (FMUSP): Divisão de Neurologia

IIHospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo (FMUSP): Instituto de Medicina Nuclear

SUMMARY

The functional significance of MRI-defined mesial temporal sclerosis in temporal lobe epilepsy (TLE) is not completely established. In order to study the possible relationship between signals of mesial temporal sclerosis on MRI and interictal SPECT findings we selected 18 patients with complex partial seizures, unilateral temporal EEG focus and normal CT. The EEG focus was defined by the presence of interictal sharp waves and slow background on several scalp EEG obtained during many years of follow up in all patients and by ictal recordings with sphenoidal electrodes in 12 patients. Group I comprised patients (n=11) in whom MRI showed mesial temporal sclerosis; group II patients (n=7) had normal MRIs. All patients were submitted to interictal 99m-Tc HMPAO injections with concomitant EEG monitoring. Lateralized hypoperfusion ipsilateral to the EEG was found in 13 patients (72%). In all Group II and in 6 Group I patients a temporal hypoperfusion was found. This SPECT study showed a higher positivity rate in patients with normal MRI than previously reported. On the other hand, in all these group II patients a neocortical origin of epileptic focus was suspected on clinical or electroencephalographic basis. Positive SPECT findings may be at least as prevalent in neocortical as in mesiolimbic epilepsy.

Key words: epilepsy, temporal lobe epilepsy, SPECT, MRI.

RESUMO

O significado funcional dos sinais de esclerose mesial temporal observados em ressonância magnética ainda não está estabelecido. Para estudar as relações entre sinais de esclerose mesial temporal na ressonância magnética e alterações no SPECT intercrítico, foram selecionados 18 pacientes com epilepsia do lobo temporal cujo diagnóstico foi definido pela presença de descargas de ondas agudas e alentecimento da atividade de base em vários EEG obtidos durante vários anos de seguimento em todos os pacientes e por registros críticos com eletrodos esfenoidais em 12 pacientes. No grupo I foram incluídos pacientes (n=11) com sinais de esclerose mesial temporal na ressonância magnética; no grupo II (n=7), pacientes com ressonância normal. Em todos os casos a injeção do Tc 99 HMPAO foi realizada no período intercrítico com monitorização EEG. Foi observada hipoperfusão lateralizada ipsolateral ao foco definido pelo EEG em 13 pacientes (72%). Todos os pacientes do grupo II e 6 pacientes do grupo I tiveram hipoperfusão temporal. Este estudo mostrou maior positividade de SPECT em pacientes com ressonância magnética normal do que tem sido referido na literatura. Como os pacientes do grupo II tinham sinais clínicos ou eletrencefalográficos sugestivos de origem neocortical de suas crises epilépticas, postulamos que hipoperfusão em estudos de SPECT pode ser demonstrada tanto em epilepsia temporal neocortical como mesiolímbica.

Palavras-chave: epilepsia, epilepsia temporal, SPECT, ressonância magnética.

Texto completo disponível apenas em PDF.

Full text available only in PDF format.

Aceite: 4-março-1994.

Estudo parcialmente financiado por FAPESP - Fundação de Amparo à Pesquisa do Estado de São Paulo.

Dra. Elza Márcia Targas Yacubian - Divisão de Neurologia, Hospital das Clínicas, FMUSP - Av. Dr. Eneas de Carvalho Aguiar 255, Instituto Central - sala 5011 A - 05403-000 São Paulo SP - Brasil.

  • 1. Abou-Khalil BW, Siegel GJ, Sackellares JC, Gilman S, Hichwa R, Marshall R. Positron emission tomography studies of cerebral glucose metabolism in chronic partial epilepsy. Ann Neurol 1987, 22: 480-486.
  • 2. Ancri D, Semah F, Adam C, Laplane D, Baulac M. Spect study of temporal lobe epilepsy patients with hippocampal atrophy demonstrated by MRI. (abstr). Epilepsia 1991, 32(Suppl 3): 98.
  • 3. Andersen AR, Gram L, Kjaer L, Fuglsang-Frederiksen A, Herning M, Lassen NA, Dam M. SPECT in partial epilepsy: identifying side of the focus. Acta Neurol Scand 1988, 78 (Suppl 117): S90-94.
  • 4. Berkovic SF, Newton MR, Rowe CC. Localization of epileptic foci using SPECT. In: Lüders HO (ed). Epilepsy surgery. New York: Raven Press, 1991, p 251-256.
  • 5. Bluestone DL, Engelstad BL, Barbaro NM, Laxer KD. Tc-HMPAO SPECT imaging for intractable complex partial seizures of temporal lobe origin (abstr). Epilepsia 1989, 30: 690.
  • 6. Convers P, Bierme T, Ryvlin P, Revol M, Fischer C, Froment JC, Maugeniere F. Brain magnetic resonance imagin (MRI) in drug-resistent partial epilepsy: a study of 100 patients with normal CT scans. Rev Neurol 1990, 146: 330-337.
  • 7. Duval E, Coubes P, Badly-Moulinier M, Valmier J, Touchon J. Regional cerebral blood flow tomography by intravenous injection of Tc 99m HMRAO in partial epilepsy (abstr). Epilepsia 1989, 30: 718.
  • 8. Engel J Jr, Kuhl DE, Phelps ME, Mazziotta JC. Interictal cerebral glucose metabolism in partial epilepsy and its relation to EEG changes. Ann Neurol 1982, 12: 510-517.
  • 9. Hajek M, Antonini A, Leenders KL, Wieser HG. Mesiobasal versus lateral temporal lobe epilepsy: metabolic differences in the temporal lobe shown by interictal 18F-FDG positron emission tomography. Neurology 1993, 43:79-86.
  • 10. Jibiki I, Kubota T, Fujimoto K, Yamaguchi N, Matsuda H, Tsuji S, Hisada K. High reproducibility of regional abnormalities on interictal 123 I-IMP SPECT brain scans in adults with partial epilepsy. Eur Arch Psychiatry Clin Neurosci 1990, 240:5-8.
  • 11. Kuzniecky R, De La Sayette V, Ethier R, Melanson D, Andermann F, Bercovic S, Robitaile Y, Olivier A, Peters T, Frindel W. Magnetic resonance imaging in temporal lobe epilepsy: pathological correlations. Ann Neurol 1987, 22:341-347.
  • 12. Lee BI, Markand ON, Wellman HN, Siddiqui AR, Mock B, Krepshaw J, Kung H. HIPDM single photon emission computed tomography brain imaging in partial onset secondarily generalized tonic-clonic seizures. Epilepsia 1987, 28:305-311.
  • 13. Mc Lachlan RS, Nicholson RL, Black NS, Carr T, Blume WT. Nuclear magnetic resonance imaging, a new approach to the investigation of refractory temporal lobe epilepsy. Epilepsia 1985, 26:555-562.
  • 14. Moretti JL, Defer G, Cinotti L, Cesaro P, Degos JD, Vigneron N, Ducassou D, Holman BL. "Luxury perfusion"with 99m Tc-HMPAO and 123 I-IMP SPECT imaging during the subacute phase of stroke. Eur J Nucl Med 1990, 16: 17-22.
  • 15. Rowe CC, Berkovic SF, Austin MC, Saling M, Kalnins RM, McKay WJ, Bladin PF. Visual and quantitative analysis of interictal SPECT with technetium-99m-HMPAO in temporal lobe epilepsy. J Nucl Med 1991, 32:1688-1694.
  • 16. Ryvlin P, Garcia-Larrea L, Philippon B, Froment JC, Fischer C, Revol M, Maugui_re F. High signal intensity on T2-Weighted MRI correlates with hipoperfusion in temporal lobe epilepsy. Epilepsia 1992, 33:28-35.
  • 17. Sackellares JC, Siegel GJ, Abou-Khalil BW, Hood TW, Gilman S, McKeever PE, Hichwa RD, Hutchins GD. Differences between lateral and mesial temporal metabolism interictally in epilepsy of mesial temporal origin. Neurology 1990, 40:1420-1426.
  • 18. Theodore WH, Dorwart R, Holmes M, Porter RJ, Di Chiro G. Neuroimaging in refractory partial seizures: comparison of PET, CT, and MRI. Neurology 1986, 36:750-759.

Publication Dates

  • Publication in this collection
    19 Jan 2011
  • Date of issue
    Sept 1994
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