Two women with recurrent falls: La maladie des genoux bleus alias cryptogenic drop attacks

Two women, aged 79 and 56, reported recurrent falls for several years without any prodromes or residues, without any known features of either syncope or seizure, without any detectable causative condition and seemingly without revealing any pathognomonic signs in the clinical examination. In both cases, the falls occurred only while walking and without loss of consciousness. These falls resulted always in dropping forward with pouncing on the knees. There had never been an injury other than contusions of the knees. Indeed, inspection of the knees of one of these patients showed signs of contusion with erosions and scars of different ages, whereas on the whole body no other wounds or dermatological lesions could be detected. What could that be? Cryptogenic drop attacks--or in French and more descriptively: La maladie des genoux bleues!