Cerebral Perfusion SPECT Imaging in Epileptic and Nonepileptic Seizures

Mj, Blend; Oa, de León; Th, Jobe; Q, Lin; Jj, Sychra; Gaviria, Moisés

doi:10.1097/00003072-199706000-00003

Cited by 16 publications

(9 citation statements)

References 10 publications

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“…Video-EEG monitoring is crucial because it allows careful and repeated analysis of the clinical characteristics and possible electroclinical correlations. Recently, in two cases in which the use of video-monitored EEG alone was insufficient to make definitive diagnoses, Blend et al (173) proposed the use of compared ictal and interictal Tc-99m HMPAO brain perfusion SPECT imaging examinations.…”

Section: Instrumental Differential Diagnosis With Eeg or Video-eegmentioning

confidence: 99%

Behavioral, Psychotic, and Anxiety Disorders in Epilepsy: Etiology, Clinical Features, and Therapeutic Implications

1999

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Summary: This chapter deals with some aspects of psychiatric disturbances in people with epilepsy. Because depression and its treatment are extensively described later in this issue, they are not discussed here. The same pertains to forced normalization. Key Words: Epilepsy-Anxiety-PsychosisDepress ion-Qua1 i ty of 1 i fe-Ps e u do s ei zure s-A n t idepressants-Antipsychotics-Antiepileptic drugs.Although most people with epilepsy lead a normal emotional and cognitive life, neurobehavioral problems can be found in a large number of patients. Higher rates of psychopathology are observed in people with epilepsy relative to the general population (1,2), to other neurologic control groups (3), and to people with chronic nonneurologic disorders (1,4). In particular, increased psychopathology is more common in temporal lobe epilepsy (TLE) than in generalized epilepsy (5). Nevertheless, many issues remain highly controversial, owing in part to several methodologic problems, such as the nosographic approach, the sample examined, the type of control groups, the comparison among nonhomogeneous forms of epilepsy, and the different antiepileptic drugs (AEDs).Psychiatric disturbances can be related either to involvement of brain structures (biologic pathogenesis) or to the chronic characteristics of epilepsy (psychosocial pathogenesis). These psychiatric symptoms may develop in relationship to the seizures (in prodromal, ictal, or postictal periods) but more commonly are present in a chronic interictal condition.The wide range of clinical diversity is related to the anatomic foci, to patterns of spread, and to biologic or psychological differences among patients. Interictal behavioral changes in epilepsy remain controversial and difficult to define, mainly because pathogenesis may be attributable to several factors, such as epilepsy itself, possible brain lesions, the AEDs prescribed, and psychosocial problems (6). On the other hand, the existence of cognitive changes in epilepsy is well established, and Addrress correspondence and reprint requests to Dr. Riccardo Tom at Dipartimento di Neuroscienze, via Cherasco 11, 10126 Torino, Italy.sometimes the presence of cognitive disorders can facilitate the appearance of psychiatric disturbances (7).One of the most widely discussed problems is the incidence of psychiatric pathology in epilepsy, with a wide range of values in the literature related to the type of study. Epilepsy is characterized by a broad spectrum of severity. Ideally, patients for study trials should be selected consecutively from a general epilepsy population, but most epidemiologic studies are carried out in centers for epilepsy and include many refractory subjects who demonstrate a range of pathologic disturbances more severe than those observed in the general population of patients with epilepsy. In community studies, the prevalence of associated psychiatric disorders is low, whereas in specialty referral centers, particularly those serving indigent populations, the prevalence can rise to 25-50%: Among patient...

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Section: Instrumental Differential Diagnosis With Eeg or Video-eegmentioning

confidence: 99%

Behavioral, Psychotic, and Anxiety Disorders in Epilepsy: Etiology, Clinical Features, and Therapeutic Implications

1999

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“…To the best of our knowledge, quantitative SPECT subtraction analysis has been performed in only two reported patients in whom the SPECT results contributed significantly to correct classification of the paroxysmal events. 39 Baseline brain perfusion was normal in the first patient, who was considered to be suffering from nonepileptic seizure disorder. Ictal SPECT study, however, revealed an area of relative hyperperfusion in the right temporal lobe extending to the right frontobasal and frontolateral regions.…”

Section: Discussionmentioning

confidence: 98%

“…Interictal brain perfusion was normal, and subtracted SPECT images showed minimal blood flow of 15%-20% during ictus in frontal lobes bilaterally and left temporal lobe, reported to be suggestive of a nonepileptic seizure disorder. 39 The use of quantitative subtraction images may be even more pertinent in certain situations, such as in the nonepileptic versus epileptic quandary in which frequent interictal abnormalities may provide greater difficulty for visual interpretation; when perfusion changes are small in degree; and when the "difference" is a fall in perfusion. An individual protocol with established normal values for variability at each center using this technique is important in correct interpretation.…”

Section: Discussionmentioning

confidence: 99%

The Role of Quantitative Ictal SPECT Analysis in the Evaluation of Nonepileptic Seizures

Spencer²,

Corsi³

et al. 1999

Journal of Neuroimaging

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Nonepileptic seizures may represent difficult diagnostic problems. Identifying their presence and frequency is critical for determining appropriate treatment. The authors investigated the value of quantitative perfusion changes as measured by ictal single-photon emission tomography (SPECT) difference images in differentiating nonepileptic from epileptic seizures. Eleven patients with a clinical suspicion of nonepileptic events had ictal and interictal technetium-99m hexamethylpropylene amine SPECT scans during continuous audiovisual surface electroencephalogram (EEG) monitoring. The authors analyzed perfusion difference images based on registration, normalization, and subtraction of ictal and interictal SPECT images. The difference images were registered to each patient's magnetic resonance imaging scan to anatomically localize ictal perfusion changes. Three of 11 patients also carried the diagnosis of epilepsy and were taking antiepileptic medication. Five patients were taking antiepileptic drugs, but the diagnosis of epilepsy was not confirmed. In all patients, continuous video EEG monitoring revealed no ictal EEG findings. In nine of these patients, visual interpretation of ictal SPECT was suggestive of localized increased (n = 6) or decreased perfusion (n = 3). In all patients, however, no blood flow changes were noted on quantitative SPECT analysis with injections performed during the seizure-like event, suggesting the diagnosis of pseudoseizures. The authors' results suggest that quantitative ictal SPECT analysis is a useful tool in the diagnosis of nonepileptic seizures.

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“…The spatial resolution of EEG/EMT techniques is still quite limited (about 25mm with the current electrode setting) and investigators generally need to rely on other modalities in order to improve the localization of the most likely epileptic focus(-ci) 4,13 . MRI data sets exhibit excellent soft tissue contrast and may show lesion(s) or abnormal brain tissue.…”

Section: 21 Phase I Investigationmentioning

confidence: 99%

<title>Model-based multiconstrained integration of invasive electrophysiology with other modalities</title>

Bidaut

2001

SPIE Proceedings

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Following recent developments, most brain imaging modalities (MR, CT, SPECT, PET) can nowadays be registered and integrated in a manner almost simple enough for routine use. By design though, these modalities are still not able to match the principles and near real-time capabilities of the much simpler (but of lower spatial resolution) EEG, thus the need to integrate it as well, along with -for some patients -the more accurate invasive electrophysiology measurements taken directly in contact with brain structures.A standard control CT (or MR) is routinely performed after the implantation of invasive electrodes. After registration with the other modalities, the initial estimates of the electrodes' locations extracted from the CT (or MR) are iteratively improved by using a geometrical model of the electrodes' arrangement (grids, strips, etc.) and other optional constraints (morphology, etc.).Unlike the direct 3D pointing of each electrode in the surgical suite -which can still act as a complementary approachthis technique estimates the most likely location of the electrodes during monitoring and can also deal with non cortical arrangements (internal strips, depth electrodes, etc.).Although not always applicable to normal volunteers because of its invasive components, this integration further opens the door towards an improved understanding of a very complex biological system.

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Cerebral Perfusion SPECT Imaging in Epileptic and Nonepileptic Seizures

Cited by 16 publications

References 10 publications

Behavioral, Psychotic, and Anxiety Disorders in Epilepsy: Etiology, Clinical Features, and Therapeutic Implications

Behavioral, Psychotic, and Anxiety Disorders in Epilepsy: Etiology, Clinical Features, and Therapeutic Implications

The Role of Quantitative Ictal SPECT Analysis in the Evaluation of Nonepileptic Seizures

<title>Model-based multiconstrained integration of invasive electrophysiology with other modalities</title>

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