Relationship of Pre- and Postanesthetic EEG Abnormalities to Enflurane-Induced Seizure Activity

Kj, Burchiel; Jj, Stockard; Rk, Calverley; Nt, Smith

doi:10.1213/00000539-197707000-00010

Cited by 30 publications

(13 citation statements)

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“…This conclusion is supported by the dramatic differences we observed between the elevated multiunit, hemodynamic, and metabolic responses associated with fast-poly-spike activity in the hippocampus and the corresponding decreases associated with large-amplitude slow waves in the frontal cortex during partial limbic seizures. Furthermore, while cortical seizure propagation is associated with elevated neuronal activity and cerebral metabolism, resembling hippocampal seizure activity, ictal neocortical slow activity more closely resembles slow oscillations seen in humans during various states of depressed brain function, such as slow-wave sleep (Achermann and Borbely, 1997), encephalopathy (Ebersole and Pedley, 2003; Plum and Posner, 1980), and surgical anesthesia (Burchiel et al, 1977; Clark and Rosner, 1973). Interestingly, we observed that neocortical slow waves and depressed neuronal activity and metabolism continue into the postictal period, when impaired consciousness often persists in human TLE (Blumenfeld et al, 2004a; Blumenfeld et al, 2004b).…”

Section: Discussionmentioning

confidence: 99%

Remote Effects of Focal Hippocampal Seizures on the Rat Neocortex

Englot

Mishra²,

Mansuripur³

et al. 2008

J. Neurosci.

132

205

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Seizures have both local and remote effects on nervous system function. Whereas propagated seizures are known to disrupt cerebral activity, little work has been done on remote network effects of seizures that do not propagate. Human focal temporal lobe seizures demonstrate remote changes including slow waves on electroencephalography (EEG) and decreased cerebral blood flow (CBF) in the neocortex. Ictal neocortical slow waves have been interpreted as seizure propagation; however, we hypothesize that they reflect a depressed cortical state resembling sleep or coma. To investigate this hypothesis, we performed multimodal studies of partial and secondarily generalized limbic seizures in rats. Video/EEG monitoring of spontaneous seizures revealed slow waves in the frontal cortex during behaviorally mild partial seizures, contrasted with fast polyspike activity during convulsive generalized seizures. Seizures induced by hippocampal stimulation produced a similar pattern, and were used to perform functional magnetic resonance imaging weighted for blood oxygenation and blood volume, demonstrating increased signals in hippocampus, thalamus and septum, but decreases in orbitofrontal, cingulate, and retrosplenial cortex during partial seizures, and increases in all of these regions during propagated seizures. Combining these results with neuronal recordings and CBF measurements, we related neocortical slow waves to reduced neuronal activity and cerebral metabolism during partial seizures, but found increased neuronal activity and metabolism during propagated seizures. These findings suggest that ictal neocortical slow waves represent an altered cortical state of depressed function, not propagated seizure activity. This remote effect of partial seizures may cause impaired cerebral functions, including loss of consciousness.

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Section: Discussionmentioning

confidence: 99%

Remote Effects of Focal Hippocampal Seizures on the Rat Neocortex

Englot

Mishra²,

Mansuripur³

et al. 2008

J. Neurosci.

132

205

View full text Add to dashboard Cite

show abstract

“…Of course the ideal would produce anesthesia and not convulsions (but note that we've had more than one useful anesthetic that, incidentally, occasionally produced convulsions. )25,26 The ideal anesthetic would have a potency that would allow administration of lots of oxygen. It would be halogenated because it needed to be nonflammable.…”

Section: Summary Statementmentioning

confidence: 99%

After You, Please

Eger

2010

Anesthesiology

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“…111 Enflurane may also induce epileptiform discharges including spikes and spike-and-slow wave complexes not only in patients with a known history of seizures but also in normal subjects undergoing elective surgery. 111 Enflurane may also induce epileptiform discharges including spikes and spike-and-slow wave complexes not only in patients with a known history of seizures but also in normal subjects undergoing elective surgery.…”

Section: General Anesthesiamentioning

confidence: 99%