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REM sleep components predict the response to initial treatment of infantile spasms
J Kohyama1, J Sugimoto, M Itoh
1Department of Pediatrics, Faculty of Medicine, Tokyo Medical and Dental University, Yushima, Japan.
Insights
The phasic inhibition index (PII) can predict treatment response in infantile spasms (ISs). Higher PII indicates a poorer response to conventional anticonvulsants, suggesting a need for alternative therapies.
Area of Science:
- Neurology
- Sleep Medicine
- Pediatric Neurology
Background:
- Infantile spasms (ISs) are a severe epilepsy syndrome in infants.
- Assessing treatment response is crucial for optimal management and avoiding ineffective therapies.
- The phasic inhibition index (PII) during REM sleep may offer insights into ISs pathophysiology and treatment outcomes.
Purpose of the Study:
- To investigate the utility of the phasic inhibition index (PII) in predicting the response to conventional anticonvulsant (AED) therapy in patients with infantile spasms (ISs).
- To differentiate between good responders (GRs) and poor responders (PRs) to AEDs using REM sleep components.
- To potentially guide treatment decisions and avoid hormonal therapy in ISs.
Main Methods:
- Retrospective analysis of REM sleep (REMS) recordings in 15 IS patients before medication initiation.
- Classification of patients into good responders (GRs) and poor responders (PRs) based on the need for additional hormonal therapy.
- Calculation and comparison of the phasic inhibition index (PII), rapid eye movement bursts (RBs), and phasic chin muscle activity (PCMA) between groups.
Main Results:
- Patients with ISs exhibited significantly lower REM sleep duration compared to controls.
- While REM sleep duration was lower in GRs than PRs, this difference was not statistically significant.
- The average PII was significantly higher in poor responders (12.6+/-3.4) compared to good responders (6.1+/-1.7) (p < 0.001).
- Frequencies of RBs and PCMA did not differ significantly among GRs, PRs, and controls.
Conclusions:
- The phasic inhibition index (PII) is a valuable biomarker for distinguishing between good and poor responders to conventional AEDs in infantile spasms.
- Elevated PII may indicate a reduced likelihood of response to standard anticonvulsant treatment in ISs.
- PII could aid in early identification of patients requiring escalated or alternative treatment strategies.
Purpose:
The phasic inhibition index (PII) is the rate of the simultaneous occurrence of rapid eye movement bursts (RBs) and phasic chin muscle activity (PCMA) during rapid eye movement sleep (REMS). PII is low insofar as physiologically occurring REM-related phasic inhibition acts on chin muscles. Previously we found that PII was significantly higher in patients with infantile spasms (ISs) who had a recurrence of convulsions than in patients with ISs who exhibited no recurrence. We aimed to predict the response of patients with ISs to conventional anticonvulsants (AEDs) by means of REMS components including PII, expecting to facilitate avoidance of potentially hazardous hormonal therapy.
Methods:
REMS, recorded before the beginning of any medication, was retrospectively examined in 15 patients with ISs. The patients were classified into two groups according to the response to initial treatment with conventional AEDs. Conventional AEDs were enough to control the spasms in six good responders (GRs), whereas further hormonal therapy was required in nine poor responders (PRs) to control the spasms.
Results:
The amount of REMS was significantly lower in patients with ISs than in controls. GRs had less REMS than did PRs, although no significant difference was observed. Although the frequencies of RB and PCMA showed no significant differences among GRs, PRs, and controls, the average PII value in PRs (12.6+/-3.4; mean+/-SD) was significantly (p < 0.001) higher than that in GRs (6.1+/-1.7).
Conclusions:
PII is a useful parameter for differentiating GRs from PRs.