By Dr Ananya Mandal, MD
How do we move?
Movement, although seemingly simple like picking up a bit of paper, is actually a complex process that requires activities of several different parts of the brain working in tandem with muscles and nerves.
The thought areas of the brain trigger or stimulate the motor area to send signals to the muscles that finally carry out the action.
Throughout the action there is a constant to and from of information between the brain and the muscles via nerves of the spinal cord. This regulates the power, speed, coordination and balance necessary for a smooth action.
Gait or normal locomotion or walking, running etc. is another complex area of movement that in addition requires maintenance of posture and balance. (1-5)
What are movement disorders?
Movement disorders are neurological syndromes where they may be excess of movement or a paucity of movement that is not connected to weakness, paralysis of spasticity of the muscles.
They affect the speed, fluency or smoothness, quality, and ease of movement.
Causes of movement disorders
Most movement disorders are associated with pathological changes in the brain especially in an area of the brain called the basal ganglia. This region is part of the grey matter that lies deep within the brain.
The defects may also lie in the base of the brain or cerebellum. This leads to difficulty in walking, locomotion or maintenance of posture and normal body balance.
Movement disorders are widely prevalent and many of them have genetics as the common cause.
Impact of movement disorders
The impact can be enormous, with loss of employment, inability to drive and difficulties in performing activities of daily living including those of personal hygiene.
Progression of movement disorders
Most movement disorders begin slowly and progress to a more severe form if left untreated. Sometimes they begin as weakness or stiffness of muscles or there may be twitches and tics.
How common are movement disorders
Given that movement and gait are complex phenomenon, problems with them are widespread since minor changes in the pathways and components of movement may affect smooth workings of motion.
The most common movement disorder is essential tremor. It affects one in 20 people under the age of 40 and one in five people over 65.
The disorder is characterized by shaking of the hand or fingers when it attempts to perform a task.
Restless leg syndrome
Another common condition is called restless leg syndrome and affects nearly one in 10 individuals.
Parkinson’s disease is the best known movement disorder. It affects one in 500 individuals and in most cases is caused by genetic predisposition or exposure to certain drugs and toxins.
Although less common than other movement disorders, Parkinson’s disease can severely impair quality of life because they hamper regular movement and walking about and make the sufferer dependent on their carers.
The disease is characterized by rigidity of muscles, tremors and shaking and a short “shuffling” gait which eventually becomes difficult.
Dystonia is another type of movement disorder where there is excessive spasm of a group of muscles making them painful and difficult to move.
This leads to abnormal postures or writhing, twisting movements of part of the body. Dystonias affect 0.4% of the population. (1-5)
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)