Examination of the autonomic nervous system at the bedside.

Autonomic function is an integral part of the assessment of neurological disorders. However, pragmatically, it is often the most neglected part of neurological examination and is often limited to testing for orthostatic hypotension. Testing the autonomic nervous system may aid in the early diagnosis of neurodegenerative disorders, thereby enabling the initiation of neuroprotective strategies and resulting in improved quality of life in this group of patients. It may also enable differentiation between certain atypical parkinsonisms, such as Multiple System Atrophy and Dementia with Lewy Bodies, in which autonomic dysfunction is early and usually profound compared to Parkinson's disease. Our review focusses on the "first-line" autonomic function tests which can be done at the bedside and require use of minimal equipment and provide insights into cardiovascular, pupillary and sudomotor function. The use of minimal equipment underscores the value of these tests in resource-constrained settings as a major unmet need, thereby saving resources and avoiding delays in diagnosis and treatment.