Role of Galanin Neuropeptide in Pathogenesis of Postural Disorders in Parkinson’s Disease

INTRODUCTION: Postural disorders in Parkinson’s disease (PD) are symptoms with poorly understood pathogenesis, and the early objective diagnosis is difficult. In the literature, the influence of galanin neuromodulator on many structures of peripheral and central nervous system has been described, which indicates the probable involvement of the nervous system in the formation of motor disorders in PD. AIM: To study the content of galanin neuromodulator in blood serum of patients with PD and to determine its effect on clinical manifestations of postural disorders. MATERIALS AND METHODS: Seventy-three patients with PD diagnosis were examined, the control group included 22 healthy volunteers. The complaints, history and neurological status were evaluated. In the main group, ‘classic’ complaints and clinical manifestations were identified. The Hoehn and Yahr unified rating scale for PD was used. The content of galanin in blood serum was determined using the enzyme-linked immunoassay. RESULTS: The stage of the disease on average was 2 [2; 3], severity of motor deficit on the unified PD assessment scale was 46 [36; 56] points. In 8 patients, severe postural disorders were identified, moderate disorders — in 21, mild disorders — in 28 patients, very mild — in 8 patients. The level of galanin in the main group was 6.0 [4.2; 10.3] pg/ml, which is considerably lower than in the control group (16.9 [9.8; 18.1] pg/ml; р = 0.001). The correlation analysis revealed the relationship between the level of galanin and severity of postural disorders (R = -0.73; p = 0.001). With the content of galanin above 26 pg/ml, no postural disorders were present in the patients, the content 8 pg/ml — 26 pg/ml was associated with the minimal and mild disorders, 5 pg/ml – 8 pg/ml — with moderate disorders, and the content below 5 pg/ml — with severe disorders. CONCLUSION: Reduction of serum galanin level is associated with the degree of severity of postural disorders in Parkinson’s disease.