Vagus nerve stimulation in Parkinson's disease

INTERVENTION: Patients will be allocated randomly to one of two intervention arms, ‐ active nVNS or sham nVNS, such that both patient and experimenter will be blinded to the intervention. After the baseline assessments (motor and non‐motor symptoms) patients and carers will be trained in the use of for using the sham/active VNS device on the left side of the neck. They will be and asked to deliver the intervention in their at home for one month using a standard dose as per (total 12 minutes of stimulation voltage and current per day). At the end of one month the patients will be re‐assessed. After a washout period of one month the same patients will be then allocated to the alternate treatment arm and the same process is followed. The nVNS device produces a proprietary electrical signal that delivers a low voltage (peak, 24 V) and a maximum output current of 60 mA. Users adjust the stimulation amplitude within a preset range. Two stainless steel contact surfaces coated with a conductive gel enable delivery of stimulation to the neck in the vicinity of the vagus nerve (figure e‐1 on the Neurology® Web site at Neurology.org). The sham device is identical in appearance, weight, visual and audible feedback, and user application and control but does not deliver identical electrical stimulation. Each treatment consists of two 2‐minute self‐administered stimulation delivered 5–10 minutes apart to the left side of the neck at 3 pre‐specified times every day: (1) within 1 hour of awakening; (2) 6–8 hours after the first treatment; and (3) 6–8 hours after the second treatment. The devices were dispensed in a randomised and blinded manner. Simple randomisation was performed using a computer‐generated list of random numbers to assign either nVNS CONDITION: Idiopathic Parkinson's disease ; Nervous System Diseases ; Parkinson's Disease PRIMARY OUTCOME: ; Measured at baseline and 1 month; 1. Two dimensional spatio‐temporal gait parameters derived from GAITRite walkway; 2. Motor function using UPDRS III scrore; 3. Extent of freezing of gait estimated from post hoc video analysis and FOGQ score; SECONDARY OUTCOME: ; Measured at baseline and 1 month; 1. Cognitive parameters assessed by MMSE, Mattis DRS scores; 2. Severity of REM sleep behavior disorder from REM sleep behavior disorder screening questionnaire RBDSQ; 3. Fear of fall by Fall Efficacy Scale; 4. Peripheral biomarkers from serum sample (TNF‐ Alpha, IL‐6, IL 10, reduced glutathione, superoxide dismutase); INCLUSION CRITERIA: 1. Patients with PD and FOG 2. Age ranging from 30‐80 years 3. Can walk independently at a stretch for at least 30 meters without support 4. PD patients were diagnosed as per UKPDS (full form) Brain Bank Criteria