Primary progressive multiple sclerosis: clinical and paraclinical characteristics with application of the new diagnostic criteria

The aim of our study was to analyse clinical and paraclinical characteristics of patients with multiple sclerosis (MS) with previous diagnosis of primary-progressive (PP) MS according to the Poser's criteria and further investigate if they fulfil the McDonald's diagnostic criteria for this disorder. A total of 561 MS patients were registered in the database at the Institute of Neurology, Belgrade, from 1 January 1997 to 31 December 2000 and 63 of them (11.2%) with previous diagnosis of PPMS were analysed retrospectively. Male/female ratio was 1.3:1 and mean age at onset 33.2 years. Most frequent at onset were pyramidal (in 73% of patients) and sensory symptoms (in 41% of patients); 74.6% of patients had greater than or equal to nine brain magnetic resonance imaging (MRI) lesions. Intrathecal oligoclonal immunoglobulin G (IgG) was detected in 96.7% and prolonged visual evoked potentials (VEP) P100 latency in 82.4% of patients. Of the total study group of 561 patients, 10.2% fulfilled the recently recommended McDonald's diagnostic criteria for the diagnosis of PPMS. Our findings further support the significance of the brain/spinal cord MRI, cerebrospinal fluid and VEP findings for precise diagnostic assessment in patients with suspected PP form of MS.