Recently, the development of digital EEG technology has enabled us to visualize EEG activities of wider frequency bands in addition to conventional 'Berger bands'. We could record the low frequency activities below 1 Hz and also the high frequency activities above 200 Hz, and utilize such novel information as DC shift (infra-slow) and high frequency oscillations (HFO). Both activities have been found in epileptogenic areas, and have received much attention as new surrogate biomarkers of epileptic focus. However, the definition and methods of recoding/analysis have not been well established so that it would be difficult to compare previous reports from various institutes. Previously the standardization of clinical practice parameter in recording and analysis of ictal DC shifts and ictal HFOs was proposed based on multi-institutional collaborative study about wide-band EEG analysis of ictal electrocorticogram by AMED (J. Jpn. Epil. Soc. 2017; 35: 3-13). We are now presenting the revised proposal by adding and rectifying several points after the collaboration of several academic societies of clinical neuroscience in Japan.
We investigated 126 epilepsy patients who received medical certification for fitness to drive at our adult epilepsy outpatient clinic. Of 126 patients, 25 (19.8%) had recurrence of a seizure after the medical certificate was issued. Of these 25 patients, nine exhibited poor therapeutic compliance, such as neglecting to take medicine. For patients receiving a certificate within 2 to 5 years of seizure, seizure inhibition rates were 88.3% in the 2nd year, and 75.6% in the 5th year. For patients receiving a certificate 5 years or more after seizure, seizure inhibition rates were 98.0% in both the 2nd year and the 5th year. We examined the cause of seizure recurrence in patients with good compliance. A longer period from the start of treatment to seizure inhibition, higher age of seizure onset, and electroencephalographic findings of generalized epileptic discharge were predictive factors for seizure recurrence.
The current results suggested that it is appropriate for epilepsy patients with good compliance to receive certification for fitness to drive on the basis of Japanese Road Traffic Law.
The safety and efficacy of epilepsy surgery for mesial temporal lobe epilepsy have been established. However, some patients show psychiatric comorbidity after epilepsy surgery. It is possible that psychiatric symptoms are induced by antiepileptic drugs (AED). An early withdrawal of AED after epilepsy surgery may be a risk factor for seizure recurrence.
Here we describe a case of a 19-year-old female who had intractable epilepsy. She also had focal impaired awareness seizures with epigastric rising sensation. She was diagnosed with right mesial temporal lobe epilepsy, and focus resection was thus performed. After epilepsy surgery she started having depression and aggression episodes. Therefore, the dosage of AED was reduced, and she started taking selective serotonin reuptake inhibitors at two months after surgery. Subsequently, psychiatric symptoms improved, and she remained seizure freedom.
Normal postoperative electroencephalogram findings, seizure freedom after epilepsy surgery, and complete resection may be the indications for the early withdrawal of AED.