Defining the Role of Structural Lesions and Metabolic Abnormalities in Periodic Lateralized Epileptiform Discharges

Raroque, Henry G.; Gonzales, Peter C. W.; Jhaveri, Harish S.; Leroy, Robert; Allen, Elizabeth

doi:10.1111/j.1528-1157.1993.tb02411.x

Cited by 41 publications

(21 citation statements)

References 16 publications

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“…They are most often associated with acute structural lesions, although they may also occur in the setting of metabolic derangements (1 3, [17][18][19]. We found that PEDs are also a marker of poor prognosis in SE, confirming the reports of Treiman (20) and Jaitly et al (21).…”

Section: Discussionsupporting

confidence: 87%

The EEG and Prognosis in Status Epilepticus

et al. 1999

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Summary:Purpose: To examine the relation between specific EEG features and clinical outcome, determine whether a predictable sequence of EEG patterns exists during status epilepticus (SE), and examine the relation between periodic epileptiform discharges (PEDs) and SE.Methods: EEG records of 50 patients with SE admitted to Graduate Hospital between January 1990 and July 1995 were reviewed. Ictal EEGs were available in 72%; 28% had only postictal EEGs. Poor outcome was defined as death or persistent vegetative state, and good outcome as all others. Fisher's Exact test, xz. and t tests were performed for data analysis.Results: Of 50 patients, 72% had a good outcome and 28%, a poor outcome. If PEDs were present at any time during or after SE, outcome tended to be worse (p = 0.053). With PEDs, eight (44%) of 18 had a poor outcome; without PEDs, six (19%) of 32 had a poor outcome. Etiologies for SE did not substantially differ in patients with or without PEDs, and structural abnormalities were not more associated with the presence of PEDs. PEDs were seen both early and late, during and after SE. Other EEG characteristics (lateralized vs. bilateral symmetric ictal EEG, discrete vs. continuous ictal activity, and postictal focal slowing) did not relate to outcome. No predictable sequence of EEG changes was found during SE.Conclusions: PEDs are the only EEG feature related to outcome in SE and are associated with poor outcome independent of etiology. Key Words: Status epilepticus-Periodic epileptiform discharge-PLEDs-Prognosis-EEG.Status epilepticus (SE) is a common medical emergency associated with significant morbidity and mortality. Recent estimates of the incidence of SE in the United States range from 50,000 (1) to 152,000 cases per year (1,2). Mortality in SE ranges from 2 to 27% and is higher in some subgroups (1,(3)(4)(5)(6).The EEG is an important tool in both diagnosing and managing patients with SE. Many types of EEG abnormalities can be seen during SE (7,8 nosis than the early stages of SE and that PEDs represent a late stage of SE. However, there is considerable controversy regarding the relation of PEDs to SE. PEDs, especially when lateralized, occur in the absence of seizures and have been associated with the presence of underlying structural lesions, including acute cerebral infarctions, tumors, and inflammatory conditions (8,ll). In contrast, some other studies found a close relation between seizures and PEDs (1 2,13). Although specific stages of SE have been described in an experimental model, human studies have not demonstrated any reliable EEG sequence during SE (4,14).The goals of this study were to determine whether any EEG features predict prognosis in human SE, to determine whether a predictable sequence of EEG patterns exists during SE, and to examine the relation between PEDs and SE. It is important to define which patients are at risk for poor outcome, so that new therapeutic measures can be developed on appropriate populations.

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Section: Discussionsupporting

confidence: 87%

The EEG and Prognosis in Status Epilepticus

et al. 1999

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“…In such cases, metabolic abnormalities are frequently involved (6)(7)(8). In the present case, lesions on MRI were in a small, restricted area.…”

Section: Discussionmentioning

confidence: 43%

Benign bilateral independent periodic lateralized epileptiform discharges

Fushimi¹,

Matsubuchi²,

Sekine³

et al. 2003

Acta Neurologica Scandinavica

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Bilateral independent periodic lateralized epileptiform discharges (BIPLEDs) usually appear transiently in patients with severe disturbances of consciousness and are indicative of a poor prognosis. Recurrent BIPLEDs have not previously been reported in the literature. We report a 64-year-old patient with bilateral hippocampal lesions (cerebral infarction) who exhibited persistent periodic lateralized epileptiform discharges (PLEDs) (chronic PLEDs) associated with recurrent BIPLEDs. Electroencephalography was recorded for more than 6 months. Left hemispheric PLEDs appeared first. Next, PLEDs shifted to the right hemisphere and BIPLEDs occasionally developed. Brain magnetic resonance imaging and single-photon emission computed tomography with technetium-99-hexamethyl-propyleneamine oxime was performed before and after the appearance of BIPLEDs. The patient had no remarkable clinical symptoms aside from mild memory impairment for this period of time. This is the first case of recurrent 'benign' BIPLEDs, that is, BIPLEDs with a positive prognosis.

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“…Patient 4. Axial scan (TR 2500, TE 40) shows that performing only one imaging study, especially before EEG detection of PLEDs, may limit detection of late-evolving lesions (Raroque et al, 1993). In our study, only 2 patients had scans before the EEG.…”

Section: Discussionmentioning

confidence: 71%

Lesion Localization in Periodic Lateralized Epileptiform Discharges: Gray or White Matter

Raroque

Purdy

1995

Epilepsia

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We analyzed the results of neuroimaging studies in patients with periodic lateralized epileptiform discharges (PLEDs) or bilateral independent periodic lateralized epileptiform discharges (BIPLEDs) for localization of lesions in gray or white matter to determine if "cortical isolation" is a critical mechanism in the pathogenesis of this phenomena. We assessed 32 patients who had undergone computed tomography (CT) exclusively and 8 patients who had undergone magnetic resonance imaging (MRI) with or without CT. The superior resolution necessary for adequate lesion localization allowed use of only the MRI scans from the 8 patients. Six patients had scans with cortical and subcortical gray and white matter lesions, and 1 patient had a cortical gray matter lesion only. One patient had an indeterminate scan. No patient had white matter lesions only. Our findings in patients with PLEDs and BIPLEDs correlate with postmortem data in patients with generalized periodic EEG patterns that show consistent localization of lesions in the gray matter. These findings do not support cortical isolation as the critical or sole mechanism in PLEDs or BIPLEDs.

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Defining the Role of Structural Lesions and Metabolic Abnormalities in Periodic Lateralized Epileptiform Discharges

Cited by 41 publications

References 16 publications

The EEG and Prognosis in Status Epilepticus

The EEG and Prognosis in Status Epilepticus

Benign bilateral independent periodic lateralized epileptiform discharges

Lesion Localization in Periodic Lateralized Epileptiform Discharges: Gray or White Matter

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