THE ABSENCE OR PAUCITY OF SPIKES IN INTRACTABLE TLE SUGGESTS A LESS SEVERE DISEASE
Abstract number :
1.097
Submission category :
Year :
2002
Submission ID :
1323
Source :
www.aesnet.org
Presentation date :
12/7/2002 12:00:00 AM
Published date :
Dec 1, 2002, 06:00 AM
Authors :
Anna Rosati, Frederick Andermann, Andrea Bernasconi, Fernando Cendes, Neda Bernasconi, Andre Olivier, Jean Gotman, Francois Dubeau. Department of Neurology and Neurosurgery, Montreal Neurological Hospital and Institute, Montreal, Quebec, Canada; Departmen
RATIONALE: TLE patients usually have high incidence of interictal EEG tracings with frequent interictal spikes. Only 2 % of TLE patients have no spike despite prolonged scalp EEG recordings (C. Ajmone-Marsan and L.S. Zivin, Epilepsia 1970; 11:361-381). The absence or paucity of spikes is more common in well-controlled or familial TLE. The objective of this study is to analyze clinical, EEG and imaging characteristics of non-lesional intractable TLE patients with rare or absent spikes (oligospikers).
METHODS: Between 1990 and 2000, 31 patients (11 men, mean age, 34 years) with intractable TLE were prospectively selected on the basis of the absence or paucity of spikes ([lt] 1/hour). We compared the clinical and laboratory characteristics of these individuals with a group of 27 age-matched (10 men, mean age, 38 years) randomly selected non-lesional TLE patients who had frequent spikes.
RESULTS: Oligospikers showed a later age at seizure onset (19 vs 10 years, p=0.004), shorter disease duration (14 vs 28 years, p[lt]0.001), lower incidence of secondarily generalized tonic-clonic (SGTC) seizures (10% vs 81%, p[lt]0.001) and no status epilepticus (SE) (0 vs 22%). Also, hippocampal atrophy (HA) was less commonly found in oligospikers (58% vs 96%, p=0.001). However, there were no difference between the two groups in the incidence of family history of epilepsy, risk factors, febrile convulsions, and type of medication. Excellent surgical outcome (Engel[ssquote]s class Ia) was found in 14/23 (61%) oligospikers and 17/25 (67%) TLE patients with frequent spikes.
CONCLUSIONS: The striking lack of spikes in some patients with refractory TLE over long interval led us to think that they represent a distinct TLE group with a more benign disease course. Oligospikers have less severe epilepsy as suggested by a later age of seizure onset, shorter duration of epilepsy, rare SGTC seizures and no SE. They also have a lower incidence of HA. The similarity of etiological factors compared to patients with frequent spikes suggests that the rarity of spikes reflect a disease that is not really distinct, but less severe, particularly with respect to SGTC seizures and SE. Nevertheless, oligospikers also have frequent complex partial seizures, and their epilepsy may be severe enough to consider surgery.