The course of periodic catatonia involves both hyperkinetic and akinetic phases. These are rarely present in pure form, rather, symptoms of one pole are mixed with those of the other pole. In the presence of akinetic traits hyperkinesia displays a certain rigidity. Movements occur with stiffness and jerkiness, and natural harmony is lost. From this change the original significance of the movements can no longer be detected. Reactive movements are no longer recognized as such; expressive movements lose their content to a great extent. Gestures turn into undefined poking movements, facial expressions turn into grimaces. This distortion of natural activity gives the excitement of periodic catatonia a parakinetic character. Even more clearly the opposite pole may be recognized as it impinges on the akinesia. Despite general rigidity of posture and facial expression aimless movement of an extremity may occur. The movements becomes uniform, either as a stereotype or iteratively. As well stereotyped postures develop in this manner; despite poverty of drive certain postures are repeatedly actively assumed. Another form of the admixture of hyperkinetic traits in akinesia is the occurrence of impulsive actions, often associated with aggressiveness. Furthermore some patients, with little provocation, suddenly burst out with exaggerated laughter. Negativistic behaviour may also imply the addition of a motor element to the akinesia.

Remissions regularly follow the acute phases. Patients with hyperkinetic states have, in fact, a relatively good prognosis. Even after several attacks, only a relatively small defect may remain. However akinesia is more often followed by permanent defect. If the defect is only mild it is characterized by general weakness, primarily psychomotor, but also involving affect. In more severe cases it is rather a matter of indifference. In any case a certain irritability exists which may easily lead to aggressive outbursts. In the final phase symptoms from both poles of the disorder still occur side by side. Besides lack of drive there may be grimacing facial movements, impulsive acting out, as well as verbal impulsivity, giving rise to "Vorbeireden" (talking-past-the-point).

Mild cases of periodic catatonia may temporarily imitate the pictures of motility psychosis; other polymorphic phasic psychoses, as well as the other two unsystematic schizophrenias may present similar relationships.