Dysdiadochokinesia
Encyclopedia
Dysdiadochokinesia, dysdiadochokinesis, dysdiadokokinesia, dysdiadokokinesis, or DDK (from Greek
dys "bad", diadocho "receive", kinesia "movement") is the medical term for an inability to perform rapid, alternating movements.
, and is the result of lesions to the cerebellar hemispheres, the posterior or frontal lobes of the cerebellum, or all of the aforementioned regions. It is thought to be caused by the inability to switch on and switch off antagonising muscle groups in a coordinated fashion due to hypotonia, secondary to the central lesion.
Dysdiadochokinesia is also seen in Friedreich's Ataxia
and multiple sclerosis
, as a cerebellar symptom (including ataxia, intentional tremor & dysarthria
).
/supination
test of the upper extremity. A simpler method using this same concept is to ask the patient to demonstrate the movement of trying a door knob or screwing in a lightbulb. The deficits become visible in the rate of alternation and the completeness of the sequence, involving both motor coordination and sequencing.
When testing for this condition in legs ask the patient to tap your hand as quickly as possible with the ball of each foot in turn. Movements tend to be slow or awkward. The feet normally perform less well than the hands.
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
dys "bad", diadocho "receive", kinesia "movement") is the medical term for an inability to perform rapid, alternating movements.
Causes
It is a feature of cerebellar ataxiaCerebellar ataxia
Cerebellar ataxia is a form of ataxia originating in the cerebellum.-References:...
, and is the result of lesions to the cerebellar hemispheres, the posterior or frontal lobes of the cerebellum, or all of the aforementioned regions. It is thought to be caused by the inability to switch on and switch off antagonising muscle groups in a coordinated fashion due to hypotonia, secondary to the central lesion.
Dysdiadochokinesia is also seen in Friedreich's Ataxia
Friedreich's ataxia
Friedreich's ataxia is an inherited disease that causes progressive damage to the nervous system, resulting in symptoms ranging from gait disturbance to speech problems; it can also lead to heart disease and diabetes....
and multiple sclerosis
Multiple sclerosis
Multiple sclerosis is an inflammatory disease in which the fatty myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms...
, as a cerebellar symptom (including ataxia, intentional tremor & dysarthria
Dysarthria
Dysarthria is a motor speech disorder resulting from neurological injury of the motor component of the motor-speech system and is characterized by poor articulation of phonemes...
).
Presentation
It is demonstrated clinically by asking the patient to tap the palm of one hand with the fingers of the other, then rapidly turn over the fingers and tap the palm with the back of them, repeatedly. This movement is known as a pronationPronation
In anatomy, pronation is a rotational movement of the forearm at the radioulnar joint, or of the foot at the subtalar and talocalcaneonavicular joints. For the forearm, when standing in the anatomical position, pronation will move the palm of the hand from an anterior-facing position to a...
/supination
Supination
Supination is a position of either the forearm or foot; in the forearm when the palm faces anteriorly, or faces up . Supination in the foot occurs when a person appears "bow-legged" with their weight supported primarily on the anterior of their feet.The hand is supine in the anatomical position...
test of the upper extremity. A simpler method using this same concept is to ask the patient to demonstrate the movement of trying a door knob or screwing in a lightbulb. The deficits become visible in the rate of alternation and the completeness of the sequence, involving both motor coordination and sequencing.
When testing for this condition in legs ask the patient to tap your hand as quickly as possible with the ball of each foot in turn. Movements tend to be slow or awkward. The feet normally perform less well than the hands.