DR RV ANAND SENIOR NEUROLOGIST SAI NEURO CLINIC CHENNAI POSTURAL INSTABILITY IN PARKINSON DISEASE the autonomic reflexes helps to maintain postural imbalance in all of us when we stand and walk.in people with parkinson diseasethese reflexes , causing a tendency to fall or loose balance.it usually occurs late in the course of disease.Asthese reflexes stop working in these patients they will have more troble with walking .they might need assistance in walking or move about in wheel chair if postural instablity occurs early it suggests it is not pure parkinson disease alone more on it to follow