EEG, PET, SPET and MRI in intractable childhood epilepsies: possible surgical correlations

Abstract

Magnetic resonance imaging (MRI), single photon emission tomography (SPET), and positron emission tomography (PET) using [18F]fluorodeoxyglucose were used in combination with scalp and scalp-video EEGs in a group of 30 pediatric patients with drug resistant epilepsy (DRE) in order to identify patients who could benefit from neurosurgical approach. Seizures were classified according to the consensus criteria of The International League Against Epilepsy. In three patients infantile spasms (IS) were diagnosed; 13 subjects were affected by different types of generalized seizures, associated with complex partial seizures (CPS) in three. In the other 14 patients partial seizures, either simple (SPS) or complex, were present. A localized abnormality was demonstrated in one patient with IS and in three patients with generalized seizures. Of the group of 14 subjects with CPS, MRI and CT were normal in 7, but SPET or PET indicated focal hypoperfusion or hypometabolism concordant with the localization of the EEG abnormalities. In 5 of the other 7 patients anatomical and functional imaging and EEG findings were concordant for a localized abnormality. It can be concluded that functional imaging combined with scalp EEGs appears to be superior to the use of only CT and MRI for selecting children with epilepsy in whom a surgical approach can be considered, in particular when CPS resistant to therapy are present.

Magnetic resonance perfusion imaging in malformations of cortical development

“…One potential confounding factor of this study is seizure activity. It is well known from nuclear medicine studies (PET and SPECT) that imaging at or close to the time of a seizure is associated with regional hypermetabolism (29), whilst hypometabolism is the most common finding interictally (7,21,32). It is highly likely that cellular metabolism is closely linked to regional cerebral blood flow, therefore causing potential changes on MR perfusion studies.…”

MR measurement of regional relative cerebral blood volume in epilepsy

“…To date, the application of first-pass dynamic MRI in TLE has not been described in the literature. Perfusion studies in epilepsy patients have been conducted using nuclear medicine techniques, such as SPECT or PET (6,9,23,24). However, the lower spatial resolution of SPECT and PET and the ionization from tracers are major concerns.…”

Proteus syndrome associated with hemimegalencephaly and Ohtahara syndrome: Report of two cases

“…18 The etiology of Ohtahara syndrome is heterogeneous and includes central nervous system (CNS) malformations, such as hemimegalencephaly, [19][20][21] porencephaly, Aicardi syndrome, 22 and other conditions. 17,[23][24][25][26][27] The prognosis is poor due to the intractability of seizures. Mortality is high, particularly among earlyonset cases, and estimated survival is 2 years.…”