Stepwise Synchronization Through the Corpus Callosum Is One Cause of Myoclonic Jerks

Cortico-muscular and cortico-cortical coherence changes resulting from Perampanel treatment in patients with cortical myoclonus

OBJECTIVE

To investigate the mechanisms by which Perampanel (PER) reduces the severity of action myoclonus, we studied on MEG signals the changes occurring in cortico-muscular coherence (CMC) and cortico-cortical connectivity in patients with progressive myoclonus epilepsies.

METHODS

The subjects performed an isometric extension of the hand; CMC and cortico-cortical connectivity were assessed using autoregressive models and generalized partial-directed coherence. The contralateral (Co) sensors showing average CMC values >0.7 of the maximum (set to 1) were grouped as central (C) regions of interest (ROI), while adjacent sensors showing CMC values >0.3 were grouped as Surrounding (Sr) ROIs.

RESULTS

Under PER treatment, CMC decreased on Co C and Sr ROIs, but also on homologous ipsilateral (Ip) ROIs; out-degrees and betweenness centrality increased in Co ROIs and decreased in Ip ROIs. The flow from Ip to Co ROIs and from activated muscles to Ip C ROI decreased.

CONCLUSION

The improvement of myoclonus corresponded to decreased CMC and recovered leadership of the cortical regions directly involved in the motor task, with a reduced interference of ipsilateral areas.

SIGNIFICANCE

Our study highlights on mechanisms suitable to treating myoclonus and suggests the role of a reduced local synchronization together a better control of distant synaptic effects.

Anterior corpus callosotomy in school-aged children with Lennox-Gastaut syndrome: a prospective study

AIMS

To compare outcomes of anterior corpus callosotomy (CCT) with anti-epileptic drugs (AEDs) treatment in school-aged children with Lennox-Gastaut syndrome (LGS).

METHODS

Sixty school-aged children with LGS were prospectively enrolled and divided into either the medicine or surgery group according the choice of the patients' caregivers. Cases in the medicine group were treated with multiple rational AEDs and patients in the surgery group underwent anterior CCT. Seizure control at 1-5 years after enrollment and changes of intelligence quotient (IQ) and quality of life (QOL) from pre-treatment to the 2-year follow-up were compared between the two groups.

RESULTS

The percentages of patients who were totally seizure-free in the surgery group were 17.4% at the 1-year follow-up, 13.0% at the 2-year follow-up and 8.7% at the 5-year follow up, and the data for patients in the medicine group were 2.9%, 5.9% and 2.9%, respectively. Significant differences were found in total seizure control between the two groups at 1, 2, and 5-year follow-up (personal χ2 test). Significant differences were found in mean changes of IQ and overall QOL between the medicine and surgery groups at the 2-year follow-up, showing positive results for the surgery group, but these changes were not related to postoperative outcomes of seizure control (t-test).

CONCLUSION

Anterior CCT is a promising treatment for school-aged children with LGS, and can present marked seizure control and improvement in QOL and IQ, all of which were significantly better than the effects of treatment with multiple AEDs.

Outcomes After Anterior or Complete Corpus Callosotomy in Children

BACKGROUND:

Corpus callosotomy (CC) is a valuable palliative surgical option for children with medically refractory epilepsy due to generalized or multifocal cortical seizure onset.

OBJECTIVE:

To investigate the extent of CC resulting in optimal seizure control in a pediatric patient population and to evaluate the modification of seizure profile after various CC approaches.

METHODS:

The records of 58 children (3–22 years of age at the time of surgery) with medically refractory epilepsy who underwent CC between 1995 and 2011 were retrospectively reviewed.

RESULTS:

Anterior two thirds callosotomy resulted in resolution of absence (P = .03) and astatic (P = .03) seizures, whereas anterior two thirds callosotomy followed by second-stage completion resulted in resolution of generalized tonic-clonic (GTC) (P = .03), astatic (P = .005), and myoclonic (P = .03) seizures in addition to a trend toward resolution of absence seizures (P = .08). Single-stage upfront complete callosotomy resulted in resolution of absence (P = .002), astatic (P < .0001), myoclonic (P = .007), and complex partial (P = .008) seizures in addition to a trend toward resolution of GTC (P = .06). In comparing a composite of subjects who underwent anterior two thirds callosotomy alone or 2-stage complete callosotomy before the second stage to complete the callosotomy with subjects who underwent upfront complete CC, a more favorable outcome was found in those with the upfront complete CC (P = .02).

CONCLUSION:

Single-stage upfront complete callosotomy is effective in relieving a broader spectrum of seizure types than anterior two thirds callosotomy or 2-stage complete callosotomy in children. The advantages of single-stage complete callosotomy must be weighed against the potentially higher risk of neurological and operative complications.