The authors systematized the descriptions of different ataxic degenerative syndromes associated with the development of pyramidal symptomatology. Demonstrated the genetic pleomorphism of hereditary spastic ataxias, described the clinical features characteristic of different types of inheritance of spastic ataxias. Based on the authors' observations and analysis of the reported data the following criteria for the diagnosis "spastic ataxia" are suggested: autosomal dominant inheritance type, with the onset on the 3rd-4th decade of life, cerebellar ataxia and dysarthria coupled with tendinous hyperreflexia and the rise of the muscular tone by the spastic type.