Motor disorders are disorders of the

nervous system In biology, the nervous system is the highly complex part of an animal that coordinates its actions and sensory information by transmitting signals to and from different parts of its body. The nervous system detects environmental changes th ...

that cause abnormal and involuntary movements. They can result from damage to the

motor system The motor system is the set of central and peripheral structures in the nervous system that support motor functions, i.e. movement. Peripheral structures may include skeletal muscles and neural connections with muscle tissues. Central structur ...

. Motor disorders are defined in the fifth edition of the ''

Diagnostic and Statistical Manual of Mental Disorders The ''Diagnostic and Statistical Manual of Mental Disorders'' (DSM; latest edition: DSM-5-TR, published in March 2022) is a publication by the American Psychiatric Association (APA) for the classification of mental disorders using a common langua ...

'' (DSM-5) – published in 2013 to replace the fourth text revision (

DSM-IV-TR The ''Diagnostic and Statistical Manual of Mental Disorders'' (DSM; latest edition: DSM-5-TR, published in March 2022) is a publication by the American Psychiatric Association (APA) for the classification of mental disorders using a common langua ...

) – as a new sub-category of

neurodevelopmental disorder Neurodevelopmental disorders are a group of disorders that affect the development of the nervous system, leading to abnormal brain function which may affect emotion, learning ability, self-control, and memory. The effects of neurodevelopmental ...

s. The DSM-5 motor disorders include

developmental coordination disorder Developmental coordination disorder (DCD), also known as developmental motor coordination disorder, developmental dyspraxia or simply dyspraxia from the word 'praxis' meaning to do or act, is a neurodevelopmental disorder characterized by impair ...

stereotypic movement disorder Stereotypic movement disorder (SMD) is a motor disorder with onset in childhood involving restrictive and/or repetitive, nonfunctional motor behavior (e.g., hand waving or head banging), that markedly interferes with normal activities or results i ...

, and the

tic disorder Tic disorders are defined in the ''Diagnostic and Statistical Manual of Mental Disorders'' (DSM) based on type (motor or phonic) and duration of tics (sudden, rapid, nonrhythmic movements). Tic disorders are defined similarly by the World Health ...

s including

Tourette syndrome Tourette syndrome or Tourette's syndrome (abbreviated as TS or Tourette's) is a common neurodevelopmental disorder that begins in childhood or adolescence. It is characterized by multiple movement (motor) tics and at least one vocal (phonic) ...

Signs and symptoms

Motor disorders are malfunctions of the nervous system that cause involuntary or uncontrollable movements or actions of the body. These disorders can cause lack of intended movement or an excess of involuntary movement.Mandal, Ananya, MD. "What Are Movement Disorders?" News-Medical.net. AZO Network, 14 Oct. 2014. Web. 10 Nov. 2016. Symptoms of motor disorders include tremors, jerks, twitches, spasms, contractions, or gait problems. Tremor is the uncontrollable shaking of an arm or a leg. Twitches or jerks of body parts may occur due to a startling sound or unexpected, sudden pain. Spasms and contractions are temporary abnormal resting positions of hands or feet. Spasms are temporary while contractions could be permanent. Gait problems are problems with the way one walks or runs. This can mean an unsteady pace or dragging of the feet along with other possible irregularities.Stone, Jon. "Functional Tremor/ Spasms / Walking Problems and Other Functional Movement Disorders." Movement Disorders. ''Neurology Research Fund of the Department of Clinical Neurosciences'', 2015. Web.

Causes

Pathological changes of certain areas of the brain are the main causes of most motor disorders. Causes of motor disorders by genetic mutation usually affect the

cerebrum The cerebrum, telencephalon or endbrain is the largest part of the brain containing the cerebral cortex (of the two cerebral hemispheres), as well as several subcortical structures, including the hippocampus, basal ganglia, and olfactory bulb. In ...

.Esra, Tara, and Khodakhah, Kamran. ''Pathophysiology of Cerebellar-induced Motor Disorders'' (2012): ProQuest Dissertations and Theses. Web. The way humans move requires many parts of the brain to work together to perform a complex process. The brain must send signals to the muscles instructing them to perform a certain action. There are constant signals being sent to and from the brain and the muscles that regulate the details of the movement such as speed and direction, so when a certain part of the brain malfunctions, the signals can be incorrect or uncontrollable causing involuntary or uncontrollable actions or movements.

Diagnosis

References

{{DEFAULTSORT:Motor disorder Developmental neuroscience Extrapyramidal and movement disorders Neurological disorders Symptoms and signs: Nervous and musculoskeletal systems Neurodevelopmental disorders