Objectives. An attempt was made in the study to evaluate etiology of disorders in patients with features of a chronic cerebellar syndrome, referred to the 1st Neurology Department in the years 1998-2002.
Methods. Epidemiological and clinical features, as well as results of investigations including genetic examination, MRI brain scan, and EMG were analysed in 45 patients with a cerebellar syndrome predominating in the clinical picture as recognised by the referring physician. In the DNA analysis (at the Genetics Department) unstable trinucleotide repeats as well as features indicating the spinocerebellar ataxia (SCA) presence were looked for. Although only SCA1 and SCA2, as well as SCA8 and SCA17 (in a single family) have been diagnosed to date in Poland, in cases of familial SCA the examination covered as a rule the complete set of mutations. Most patients were analysed looking for SCA1, 2, 3, 6, 7, 8, 12, 17 and dentato-rubro-pallido-luysi atrophy (DRPLA).
Results. The patients under study were divided into 4 groups: (I) with confirmed SCA (1 and 2), (II) with symptoms of cerebellar atrophy in the MRI scan (and no SCA features detected), (III) with generalised cerebral lesions manifesting in the form of cerebellar-pyramidal-extrapyramidal syndromes (with no features of cerebellar atrophy and no confirmed SCA), and (IV) with secondary cerebellar symptoms in the course of other diagnosed CNS disorders. The main objective of the study was not quite attained, as in some patients etiology of the disorders remained unclear.
Conclusions. The major problem in differential diagnosis of chronic cerebellar syndromes seems to consist in establishing whether it is the case of (1) a primary (often genetically determined) damage to the cerebellum, (2) a generalized degenerative process affecting the brain, or (3) secondary cerebellar symptoms occurring in the course of other conditions in the CNS and predominating in later stages of the disease. Such differentiation should be based, above all, on an analysis of the presenting symptoms, their sequence and severity over time. Genetic and neurophysiological examinations as well as MRI of the brain seem to contribute most to the differential diagnosis. Moreover, obtaining a detailed genetic case history of the patient is of utmost importance.