The ability to balance is essential for a person to stand, walk and run. Maintaining this ability is a complex exercise of coordination dependent on the brain, sensory and motor nerves, and joints. There is a regular supply of information to the brain about the positions of various parts of the body and it responds with relevant instructions to the motor parts of the body. Eyes, the inner ear, skin and muscles all provide information. The cerebellum (part of the brain) collates all the information and initiates action. Balance may be aﬀected by disorders in the balancing mechanism of the inner ear (semicircular canals) such as MENIERE’S DISEASE, and inﬂammation of the labyrinth (labyrinthitis). Infection of the middle ear, such as otitis media (see under EAR, DISEASES OF), can also disturb the ability to balance, sometimes accompanied by dizziness or VERTIGO. If the cerebellum is aﬀected by disease – a tumour or a stroke, for example – the result will be faulty muscular coordination leading to clumsiness and the inability to walk properly.
Article Categories:Medical Dictionary