Advertisement

Magnetoencephalography in the detection of focal lesions in West syndrome

      Abstract

      Background: According to the international classification of epilepsy syndromes, West syndrome (WS) is a form of generalized epilepsy. However, it is known that localized lesions can induce WS and that patients with WS often subsequently develop focal seizures. We evaluated such patients using magnetoencephalography (MEG).
      Method: Fourteen patients of 3 months to 6 years of age who had or who had previously had WS were examined. MEGs were recorded using a laying-type whole-cortex MEG system with a 160-channel first-order gradiometer. Twelve-channel electroencephalography (EEG) and one-channel electrocardiography (ECG) were simultaneously recorded. Equivalent current dipoles were estimated at the point of spikes on the EEG.
      Results: Patients were classified by magnetic resonance imaging (MRI) findings into a focal lesion group (group F, n=7) and a non-focal lesion group (group N, n=7). The dipoles estimated from the MEG were classified into three groups: W, with the dipoles distributed over a wide brain area (n=7); WC, dipoles distributed over a wide area along with a dense dipole distribution in a specific cortical area (n=3); and C, closed dipole distribution in a unilateral cerebral focal area (n=4). Patients were also classified by the stage of the disease during which the MEG was recorded, and by the type of seizure they experienced. Those with hypsarrhythmia examined early in the disease all had pattern W regardless of their lesion group, whereas those examined later exhibited more diverse dipole patterns that corresponded to seizure type.
      Conclusions: Dipoles were distributed widely over bilateral cerebral cortex when patients had infantile spasms with hypsarrhythmia whether or not they had focal lesions. The dipole distribution pattern in MEG changed according to changes in seizure type.

      Keywords

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'

      Subscribe:

      Subscribe to Brain and Development
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect

      References

        • Commission on Classification and Terminology of the International League Against Epilepsy
        Proposal for revised classification of epilepsies and epileptic syndromes.
        Epilepsia. 1989; 30: 389-399
        • Mimaki T.
        • Ono J.
        • Yabuuchi H.
        Temporal lobe astrocytoma with infantile spasms.
        Ann Neurol. 1983; 14: 695-696
        • Ruggieri V.
        • Caraballo R.
        • Fejerman N.
        Intracranial tumors and West syndrome.
        Pediatr Neurol. 1989; 5: 327-329
        • Askenasi A.
        • Snead O.C.
        Infantile spasms secondary to a brain tumor.
        J Child Neurol. 1991; 6: 180-182
        • Aktan G.
        • Simsek A.
        • Aysun S.
        Brainstem tumor with infantile spasms.
        J Child Neurol. 1997; 12: 152-154
        • Chugani H.T.
        • Shields W.D.
        • Shewmon D.A.
        • Olson D.M.
        • Phelps M.E.
        • Peacock W.J.
        Infantile spasms: I. PET identifies focal cortical dysgenesis in cryptogenic cases for surgical treatment.
        Ann Neurol. 1990; 27: 406-413
        • Yamamoto N.
        • Watanabe K.
        • Negoro T.
        • Furune S.
        • Takahashi I.
        • Nomura K.
        • et al.
        Partial seizures evolving to infantile spasms.
        Epilepsia. 1988; 29: 34-40
        • Donat J.F.
        • Wright F.S.
        Simultaneous infantile spasms and partial seizures.
        J Child Neurol. 1991; 6: 246-250
        • Kubota T.
        • Aso K.
        • Negoro T.
        • Okumura A.
        • Natsume J.
        • Takada H.
        • et al.
        Epileptic spasms preceded by partial seizures with a close temporal association.
        Epilepsia. 1999; 40: 1572-1579
        • Aicardi J.
        Epilepsy in children. 2nd ed. Raven Press, New York, NY1994
        • Otsubo H.
        • Snead O.C.
        Magnetoencephalography and magnetic source imaging in children.
        J Child Neurol. 2001; 16: 227-235
        • Hattori H.
        • Shimogawara M.
        • Haruta Y.
        • Tsuyuguchi N.
        • Tsutada T.
        • Matsuoka O.
        • et al.
        Equivalent current dipole estimation of the diffuse spike or spike and wave discharges in the interictal electroencephalogram with epileptic patients.
        Epilepsia. 1999; 40: 48
        • Higuchi M.
        • Shimogawara M.
        • Haruta Y.
        • Uehara G.
        • Kawai J.
        • Ogata H.
        • et al.
        System integration and trade-offs of SQUID system for biomagnetic applications.
        Appl Superconduct. 1998; 5: 441-449
        • Satoh J.
        • Mizutani T.
        • Morimatsu Y.
        Neuropathology of the brainstem in age-dependent epileptic encephalopathy – Especially of cases with infantile spasms.
        Brain Dev. 1986; 8: 443-449
        • Chugani H.T.
        • Shewmon D.A.
        • Sankar R.
        • Chen B.C.
        • Phelps M.E.
        Infantile spasms: II. Lenticular nuclei and brain stem activation on positron emission tomography.
        Ann Neurol. 1992; 31: 212-219
        • Hrachovy R.A.
        • Frost Jr, J.D.
        • Kellaway P.
        Sleep characteristics in infantile spasms.
        Neurology. 1981; 34: 102-105
        • Miyazaki M.
        • Hashimoto T.
        • Tayama M.
        • Kuroda Y.
        Brainstem involvement in infantile spasms: a study employing brainstem evoked potentials and magnetic resonance imaging.
        Neuropediatrics. 1993; 24: 126-130
        • Baram T.Z.
        Pathophysiology of massive infantile spasms: perspective on the putative role of the brain adrenal axis.
        Ann Neurol. 1993; 33: 231-236
        • Chiron C.
        • Dulac O.
        • Bulteau C.
        • Nuttin C.
        • Depas G.
        • Raynaud C.
        • et al.
        Study of regional cerebral blood flow in West syndrome.
        Epilepsia. 1993; 34: 707-715
        • Miyazaki M.
        • Hashimoto T.
        • Fujii E.
        • Tayama M.
        • Kuroda Y.
        Infantile spasms: localized cerebral lesions on SPECT.
        Epilepsia. 1994; 35: 988-992
        • Hrachovy R.A.
        • Frost Jr, J.D.
        • Glaze D.G.
        Coupling of focal electrical seizure discharges with infantile spasms: incidence during long-term monitoring in newly diagnosed patients.
        J Clin Neurophysiol. 1994; 11: 461-464