Epileptic drop attacks in partial epilepsy: clinical features, evolution, and prognosis.

OBJECTIVES: Sudden falls have been described in patients with partial epilepsy. However, no study has detailed the clinical, EEG, and evolutive features of partial epilepsies with drop attacks.
METHODS: In a consecutive series of 222 patients with partial epilepsy admitted for uncontrolled seizures over a 10 year period, 31 patients presented with epileptic drop attacks during evolution of their illness. Twenty two patients had frontal, five temporal, and four multifocal or undefinable lobe epilepsy; 74% of the cases showed an EEG pattern of secondary bilateral synchrony during evolution. A statistical comparison of some clinical and EEG features between the patients with epileptic drop attacks and patients with partial epilepsy without drop attacks (control group of 191 patients) was carried out.
RESULTS: Seventy four per cent of patients had a poor prognosis and 45% were mentally retarded; 52% of patients with epileptic drop attacks continued to have epileptic falls associated with partial seizures and mental deterioration at the end of the follow up. These characteristics of patients with epileptic drop attacks were significantly different from the control group.
CONCLUSION: Almost all literature reports concur that the physiopathogenetic substrate of epileptic drop attacks is a mechanism of secondary bilateral synchrony. A localised epileptic focus may lead to a process of secondary epileptogenesis involving the whole brain, causing a progressive cerebral disturbance with worsening of the epileptic seizures and higher cerebral functions.