Tonic seizures of Lennox‐Gastaut syndrome: Periictal single‐photon emission computed tomography suggests a corticopontine network. Issue 12 (10th October 2013)

• Record Type: Journal Article
• Authors: Intusoma, Utcharee; Abbott, David F.; Masterton, Richard A. J.; Stagnitti, Monique R.; Newton, Mark R.; Jackson, Graeme D.; Freeman, Jeremy L.; Harvey, A. Simon; Archer, John S.
• Is Part Of: Epilepsia. Volume 54:Issue 12(2013:Dec.)
• Page Start: 2151
• Page End: 2157
• Publication Date: 2013-10-10
• Subjects: Epilepsy -- Periodicals; 616.853
• DOI: 10.1111/epi.12398
• Languages: English
• ISSNs: 0013-9580

Abstract

<abstract abstract-type="main" id="epi12398-abs-0001"> <title>Summary</title> <sec id="epi12398-sec-0001" sec-type="section"> <title>Purpose</title> <p>Lennox‐Gastaut syndrome (LGS) is a severe epileptic disorder with characteristic electroclinical features but diverse etiologies. The shared electroclinical characteristics suggest that common cerebral networks are involved in generating seizures. We sought to reveal these networks by comparing ictal and interictal single‐photon emission computed tomography (SPECT).</p> </sec> <sec id="epi12398-sec-0002" sec-type="section"> <title>Methods</title> <p>We identified 10 ictal–interictal SPECT pairs from seven patients with LGS (median age 11 years; range 1–38) who were studied during video electroencephalography (EEG)–confirmed tonic seizures. We performed a voxel‐wise comparison of ictal and interictal SPECT studies across the group. The evolution of blood flow changes was explored by examining early and late injection groups.</p> </sec> <sec id="epi12398-sec-0003" sec-type="section"> <title>Key Findings</title> <p>Median duration of tonic seizures was 10 s (range 6–29 s), and injection latency from seizure offset was −8 to 48 s. In the early injection group (<10 s; three studies), there was hyperperfusion over pons and cerebellar hemispheres (p<italic> </italic><<italic> </italic>0.05 cluster corrected family wise error), and hypoperfusion bilaterally over the pericentral region, with a trend toward hyperperfusion over bilateral superior and middle frontal gyri, and lateral parietal cortex. In the late injection group, there was hyperperfusion over midline and lateral cerebellar regions, with hypoperfusion widely over bilateral frontal regions.</p> </sec> <sec id="epi12398-sec-0004" sec-type="section"> <title>Significance</title> <p>This study suggests that the tonic seizures of LGS result from activity in a network, containing bilateral frontal and parietal association areas and the pons. We postulate that tonic seizures recruit the corticoreticular system, which connects frontal attentional areas to the pontine reticular formation, and is normally responsible for postural tone and orienting behavior.</p> </sec> </abstract>