Giant SEPs and SEP-recovery function in Unverricht-Lundborg disease

详细信息    查看全文

• 作者：E. Visani^a ; L. Canafoglia^a ; D. Rossi Sebastiano^a ; P. Agazzi^a ; ^b ; F. Panzica^a ; V. Scaioli^a ; C. Ciano^a ; S. Franceschetti^a ; ^{franceschetti@istituto-besta.it}
• 关键词：SEP recovery cycle ; Giant SEPs ; Myoclonus ; Unverricht&ndash ; Lundborg disease
• 刊名：Clinical Neurophysiology
• 出版年：2013
• 出版时间：May, 2013
• 年：2013
• 卷：124
• 期：5
• 页码：1013-1018
• 全文大小：444 K

文摘

Objective

To evaluate the relationship between sensory hyperexcitability as revealed by giant SEPs and the SEP recovery function (SEP-R) in a series of patient with progressive myoclonic epilepsy of Unverricht-Lundborg type, identified as epilepsy, progressive myoclonic 1A (EPM1A), MIM #254800.

Methods

We evaluated SEPs by applying median nerve stimuli and SEP-R using paired stimuli at inter-stimulus intervals (ISIs) of between 20 and 600 ms in 25 patients and 20 controls. The SEPs were considered ¡°giant¡± if the N20P25 and P25N33 amplitudes exceeded normal mean values by +3SD.

Results

During the paired-stimulus protocol, the SEPs elicited by the second stimulus (S2) were detectable at all ISIs but consistently suppressed in the 13 patients with giant SEPs reflecting a significantly delayed SEP-R. Maximal suppression roughly corresponded to the plateau of a broad middle latency (>100 ms) wave pertaining to the S1 response.

Conclusions

The cortical processing dysfunction generating giant SEPs in EPM1A patients consistently combines with a long-lasting suppression of hyperexcitability that leads to a delayed giant SEP-R without obstructing the response to incoming stimuli.

Significance

The delayed SEP-R is not due to true inhibition but the suppression of aberrant hyper-synchronisation sustaining giant SEPs. A broad middle latency SEP component adds a significantly suppressive effect. This suggests that cortico-subcortical circuitries contribute to both the gigantism and the delayed SEP-R.