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The interictal FDG PET often shows focal cortical hypometabolism in patients with extratemporal epilepsy and can correctly regionalize neocortical epileptic foci in more than 2/3 of the cases, even if MRI is non-localizing. In some cases, however, FDG PET overestimates the epileptogenic region, and hypometabolism may extend progressively to involve remote cortical and subcortical regions, thus establishing an epileptic network in chronic epilepsy. On the other hand, hypometabolism can occur adjacent to, rather than completely overlap with, ictal seizure onset zones. Therefore, FDG PET is best used for presurgical evaluation in combination with other clinical, electrophysiological and imaging data to guide intracranial grid placement and optimize tailored neocortical resection. When applied in this manner, the use of FDG PET can improve outcome of extratemporal lobe epilepsy surgery.

Reductions in the cerebral metabolic rate of glucose (CMRglc), a measure of neuronal function, have proven to be a promising tool in the early diagnosis of Alzheimer's disease (AD). FDG-PET imaging demonstrates progressive CMRglc reductions in AD patients, the extent and topography of which correlate with symptom severity. There is increasing evidence that hypometabolism appears during the preclinical stages of AD and can predict decline years before the onset of symptoms. This chapter provides an overview of FDG-PET results in individuals at risk for developing dementia, including presymptomatic individuals carrying mutations responsible for early-onset familial AD, patients with mild cognitive impairment (MCI), nondemented carriers of the Apolipoprotein E (ApoE) e4 allele, cognitively normal subjects with a family history of AD, subjects with subjective memory complaints, and the normal elderly followed longitudinally until they expressed the clinical symptoms of AD. Finally, this chapter discusses the potential to combine different PET tracers and cerebrospinal fluid (CSF) markers of pathology to improve the early detection of AD.

This chapter highlights the importance of the revised analysis of electroencephalography (EEG) and magnetoencephalography (MEG) spike source estimation based on comprehensive case conference discussion. It discusses two typical cases of localization-related epilepsy: case 1 as a simple situation and case 2 as a complicated situation. No “gold standard” for epileptic spike analysis in EEG or MEG has been established, so several methods must be adopted to achieve the most reasonable interpretation. However, such intense and revisional analyses may be too time-consuming in clinical settings and result in arbitrary conclusions. Therefore, the authors currently use a simple method first, that is, a single dipole model for the peak or preceding upward slope of unaveraged single spikes. In the following case conference, EEG and MEG data are reviewed with seizure semiology, anatomical magnetic resonance imaging (MRI), and ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET). If all the findings almost agree, the clinical decision can be easily made. If not, revisional analysis of EEG/MEG is recommended using averaged spikes and principal component analysis models as well as distributed source models. In addition to EEG/MEG, the authors often order revisional analysis and additional MRI and FDG-PET studies after the conference. Even further history taking will be recommended if necessary.