Epilepsy Syndromes in Patients with Childhood-Onset Seizures in Finland.
Matti Sillanpaa, M. Jalava and S Shinnar
Pediatric Neurology Vol 21, (2); 533-537, Aug 1999
This an excellent prospective study over more than 20 years. If it does not bring much new information it has the value to confirm previous studies, which were incomplete dealing only with one or two types of seizures and or epilepsies. This study is very good because it takes the ILEA classification, as the underlying frame and the reader knows exactly what seizure type or epileptic syndrome the authors refer to.
The study involves 245 patients followed prospectively. The mean age of onset of the seizures was 4 years and 3 months and the mean age at the last follow-up was 32year and 6 months.
68 (28%) had idiopathic seizures, (12 lost, 7 deaths) 49 alive at last follow-up: 42 no seizure and no treatment, 3 no seizure on treatment and 4 uncontrolled seizures. Of the 4 uncontrolled seizures 2 were Juvenile Absences and 1 was Juvenile Myoclonic E.
54 (22%) had Cryptogenic seizures, (6 lost, 4 deaths) 25 no seizure no treatment, 5 no seizure on treatment, and 14 still having seizures. Of these 14, 12 have partial seizures.
123 (50%) had remote symptomatic seizures, (7 lost, 33 deaths) 16 no seizure no treatment, 21 no seizure on treatment and 46 still having seizures.
Over all 25/245 patients lost to follow-up, 44 were dead (39 of which were NOT in remission), 83 (or one third of the patients) had no seizure no treatment (1/2 of them idiopathic, while idiopathic seizures represent only 22% of the overall population), 29 (or a bit more than 10%) had no seizure but were still needing medication's) and 64 (1/4 patient) were still experiencing seizures. A terminal remission was defined as 5 years seizure-free.
When one looks at seizure types:
Partial Seizures: 14 lost, 23 deaths, 45 no seizure no treatment, 22 no seizure with treatment, and 43 still experiencing seizures.
Generalized Seizures: 10 lost, 14 deaths, 32 no seizure no treatment, 6 no seizure with treatment, and 16 still experiencing seizures.
Overall generalized seizures have a better outcome than partial seizures, particularly when due to a cryptogenic or remote symptomatic epilepsy. Partial idiopathic seizures have an excellent prognosis. The patients with idiopathic epilepsy were all in remission except for the one having either Juvenile Absence or Juvenile Myoclonic Epilepsies.
In other words, after 20 years of epilepsy, in idiopathic seizures almost all the patients (90%) are being seizure free; in cryptogenic seizures only 2 thirds (68%) of them will enjoy a seizure free status, and in symptomatic seizures less than half (44.5 %) of them have become seizure free. Furthermore the need for medications after 20 years is 14% for idiopathic seizures, 43% for cryptogenic seizures and 80% for patients with symptomatic seizures.
This study confirms that epilepsy is not a benign condition. People with epilepsy need ongoing support and treatments for most of their life.