Eleven patients with transient paralytic attacks of obscure nature are described. Paralysis could involve face or leg alone, face and hand, or face, arm and leg. The duration varied from two minutes to one day. Four patients had brain tumors, six probably had brain infarcts, and one a degenerative process. The differential diagnosis included TIAs, migraine accompaniments, and seizures. In the absence of good evidence for the first two, the cases are discussed from the standpoint of possibly representing nonconvulsive seizure paralysis (ictal paralysis, inhibitory seizure paralysis or somatic inhibitory seizure). Because of the difficulty in defining seizures as well as TIAs and migraine in their atypical variations, a firm conclusion concerning the mechanisms of the spells was not attained. Two cases of the hypertensive amaurosis-seizure syndrome have been added as further examples of ictal deficits.