Authors :
Paresh Zanzmera, MD, DM, PDF – Government Medical College, Surat; Amit Gamit, MD – Government Medical College, Surat; Anjali Modi, MD – All India Institute of Medical Sciences, Rajkot; Ashwin Vasava, MD – Government Medical College, Surat
Rationale: Juvenile myoclonic epilepsy (JME) is a common, well-defined, age related epileptic syndrome. JME is often characterized by excellent response to treatment, if diagnosed correctly.
1 Barring few studies,
2,3 factors that are potentially predictive for seizure outcome are not entirely clear yet. Impact of EEG characteristics in form of pattern of interictal epileptiform discharges (IEDs) and activation of IEDs during awake, activation procedures, sleep and awakening from sleep on outcome of seizure frequency in JME is not clearly studied, and hence the objective of this study is to identify clinical and electroencephalographic factors that may potentially predict seizure outcome in patients with JME.
Methods: Previously diagnosed JME patients were retrieved from Epilepsy data base and clinical details including demographic variants, age of onset, duration, details of seizure (types, characteristics and frequency), previous and current AEDs and outcome in form of seizure frequency and number of AEDs required was gathered when they came for follow up after at least 6 months of diagnosis. First diagnostic EEG of each patient was reviewed and details of total duration, activation of IEDs with numbers and duration (total time) of IEDs during awake, hyperventilation (HV), post hyperventilation (PHV), photic stimulation (PS), sleep and awakening from sleep was noted without knowledge of clinical details. Activation of focal slowing or IEDs and radiographic correlates was noted. Outcome measures were improved seizure frequency and number of medication required. Statistical analysis was carried out using SPSS.
Results: In this ambispective study, we
recruited consecutive 44 (M:F 21:23) JME patients in study had mean age of 22.1± 9.52 yrs and median age of onset of epilepsy 15 (8-22) yrs. First seizure type was GTCS in 50% followed by MS in 47.7%. Twelve (27.3%) patients had family history of epilepsy. Average recording time of EEG was 68 minutes excluding one patient with overnight EEG lasting 360 minutes. Total duration of spikes was 21.36 (0.4-277.1) sec which constituted 0.58 (0-6.6) % of total duration of recording. Focal IEDs were seen in 37 (84%) patients, which were distributed in frontal (maximum), temporal, posterior head regions and multifocal. Variables in form of activation of spikes & polyspikes and wave pattern (S/PSW), presence of all types of interictal (IEDs) (abortive spikes, SWD, PSWD, and S/PSW), number of IEDs during PHV and duration of IEDs in light as well as deep sleep are statistically significantly associated with improved frequency (good outcome) in JME (p < 0.01). While none of the variables were significantly associated with requirement of number (single vs. polytherapy) of AEDs, focal slowing and number of spikes during deep sleep in EEG predicted requirement of more than one AEDs for control of seizures (p < 0.08).