The Origin of Myoclonus and Periodic Synchronous Discharges in Subacute Sclerosing Panencephalitis

Abstract

We report here a case of a patient with subacute sclerosing panencephalitis (SSPE) and we have analyzed periodic events using dipole tracing methods to clarify the origin of periodic synchronous discharges and myoclonus. Both source generators were located in the subcortical part of the cerebrum, an area adjacent to the thalamus. Although the pathophysiology of periodic events in SSPE has been controversial, dipole tracing methods may contribute to clarify the origin of periodic events in SSPE.

The manual zero potential shifting method in dipole analysis: Comparison with neuroimagings in a patient with epilepsy

“…These results suggest that dipole analysis is influenced by the error potential in the analysis of high amplitude spikes as well. There have been some studies using one dipole method, in which reliable dipolarity value has been reported to be more than 90%, 2 97% 12 and 98% 7 . Based on the results of the present study, however, it is suggested that the reliable dipolarity value was 99% or more.…”

The manual zero potential shifting method in dipole analysis: Comparison with neuroimagings in a patient with epilepsy

“…These results suggest that dipole analysis is influenced by the error potential in the analysis of high amplitude spikes as well. There have been some studies using one dipole method, in which reliable dipolarity value has been reported to be more than 90%, 2 97% 12 and 98% 7 . Based on the results of the present study, however, it is suggested that the reliable dipolarity value was 99% or more.…”

Physiological assessment of paroxysmal dystonia secondary to subacute sclerosing panencephalitis

“…This, together with the marked initial improvement with carbamazepine, suggests some form of ictal activity. Other researchers using dipole tracing techniques have suggested that the origin of periodic synchronous discharges is subcortical, in an area near the thalamus 14. Other movement disorders such as paroxysmal choreoathetosis, which we believe this phenotypically resembles,15, 16 have been associated with similar increases in caudate perfusion.…”

Movement Disorders in Patients with Subacute Sclerosing Panencephalitis: A Systematic Review

“…A variable pattern has been noted by various authors between EEG discharges and myoclonus. Dipole tracing in one patient by Yagi et al 105 showed that source generators of both the myoclonus and the periodic synchronized discharges on EEG were located adjacent to the thalamus. Ser et al evaluated myoclonus in SSPE using multiple electrophysiological tests 106 .…”

The manual zero potential shifting method in dipole analysis: Comparison with neuroimagings in a patient with epilepsy

“…These results suggest that dipole analysis is influenced by the error potential in the analysis of high amplitude spikes as well. There have been some studies using one dipole method, in which reliable dipolarity value has been reported to be more than 90%, 2 97% 12 and 98% 7 . Based on the results of the present study, however, it is suggested that the reliable dipolarity value was 99% or more.…”

Physiological assessment of paroxysmal dystonia secondary to subacute sclerosing panencephalitis

“…This, together with the marked initial improvement with carbamazepine, suggests some form of ictal activity. Other researchers using dipole tracing techniques have suggested that the origin of periodic synchronous discharges is subcortical, in an area near the thalamus 14. Other movement disorders such as paroxysmal choreoathetosis, which we believe this phenotypically resembles,15, 16 have been associated with similar increases in caudate perfusion.…”

Movement Disorders in Patients with Subacute Sclerosing Panencephalitis: A Systematic Review

“…A variable pattern has been noted by various authors between EEG discharges and myoclonus. Dipole tracing in one patient by Yagi et al 105 showed that source generators of both the myoclonus and the periodic synchronized discharges on EEG were located adjacent to the thalamus. Ser et al evaluated myoclonus in SSPE using multiple electrophysiological tests 106 .…”

The manual zero potential shifting method in dipole analysis: Comparison with neuroimagings in a patient with epilepsy

“…These results suggest that dipole analysis is influenced by the error potential in the analysis of high amplitude spikes as well. There have been some studies using one dipole method, in which reliable dipolarity value has been reported to be more than 90%, 2 97% 12 and 98% 7 . Based on the results of the present study, however, it is suggested that the reliable dipolarity value was 99% or more.…”

Physiological assessment of paroxysmal dystonia secondary to subacute sclerosing panencephalitis

“…This, together with the marked initial improvement with carbamazepine, suggests some form of ictal activity. Other researchers using dipole tracing techniques have suggested that the origin of periodic synchronous discharges is subcortical, in an area near the thalamus 14. Other movement disorders such as paroxysmal choreoathetosis, which we believe this phenotypically resembles,15, 16 have been associated with similar increases in caudate perfusion.…”

Movement Disorders in Patients with Subacute Sclerosing Panencephalitis: A Systematic Review

“…A variable pattern has been noted by various authors between EEG discharges and myoclonus. Dipole tracing in one patient by Yagi et al 105 showed that source generators of both the myoclonus and the periodic synchronized discharges on EEG were located adjacent to the thalamus. Ser et al evaluated myoclonus in SSPE using multiple electrophysiological tests 106 .…”