Clinical and epidemiological features of motor neuron disease in south-western Greece

Objective - To evaluate the epidemiological and clinical features of motor neuron disease (MND) in a region (835,000 inhabitants) of south-western Greece. Patients and methods - The medical records of all patients diagnosed with adult-onset MND at the Department of Neurology of the University Hospital of Patras from 1990 to 2003 were reviewed. Results - Overall 133 patients were identified, corresponding to a mean annual incidence rate of 1.13/100,000 population with male preponderance. Eighty-five of them were males (63.9%) and 48 (36.1%) females with a mean age of 61.4 +/- 13.3 years. The most common type of MND was amyotrophic lateral sclerosis (ALS) being identified in 111 (83.5%) patients, whereas 19 cases (14.3%) were classified as progressive spinal muscular atrophy (PSMA) and three (2.2%) cases as progressive bulbar palsy (PBP). The mean age at onset was 60.3 +/- 13.5 years, while the mean delay between age at onset and age at diagnosis was 1.3 +/- 1.1 years. The symptoms at onset involved the lower limbs in 76 (57.2%) cases, upper limbs in 32 (24%) cases, bulbar region in 22 (16.5%) cases and respiratory muscles in three (2.3%) cases. The mean survival time after onset of disease was 20.4 +/- 8.3 months for ALS patients, 15.3 +/- 4.5 months for PBP and 38.1 +/- 26.4 months for PSMA patients. Conclusions - There was no statistically significant difference in the results of the considered epidemiological parameters of our study to those reported by other similar studies. The study of the patients with MND showed a predominance of ALS patients. No potentially causative clinical associations were found and no relation between socioeconomic factors, occupational exposure and the disease was noted.