Dysdiadochokinesia

Dysdiadochokinesia, dysdiadochokinesis, dysdiadokokinesia, dysdiadokokinesis, or DDK (from Greek

Greek language

Greek , an independent branch of the Indo-European family of languages, is the language of the Greeks. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. In its ancient form, it is the language of classical...

 dys "bad", dia "across", docho "receive", kinesia "movement") is the medical term for an inability to perform rapid, alternating movements.

It is a feature of cerebellar ataxia

Cerebellar ataxia

Cerebellar ataxia is a form of ataxia originating in the cerebellum.Romberg's test can be used to distinguish cerebellar ataxia from other forms of ataxia.-References:...

, and is the result of lesions to the posterior lobe of the cerebellum.

Dysdiadochokinesia, dysdiadochokinesis, dysdiadokokinesia, dysdiadokokinesis, or DDK (from Greek

Greek language

Greek , an independent branch of the Indo-European family of languages, is the language of the Greeks. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. In its ancient form, it is the language of classical...

 dys "bad", dia "across", docho "receive", kinesia "movement") is the medical term for an inability to perform rapid, alternating movements.

Causes

It is a feature of cerebellar ataxia

Cerebellar ataxia

Cerebellar ataxia is a form of ataxia originating in the cerebellum.Romberg's test can be used to distinguish cerebellar ataxia from other forms of ataxia.-References:...

, and is the result of lesions to the posterior lobe of the cerebellum. It is thought to be caused by the inability to switch on and switch off antagonising muscle groups.

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 and speech problems to heart disease...

 and multiple sclerosis

Multiple sclerosis

Multiple sclerosis is an idiopathic disease of suspected autoimmune cause, in which the body's immune response attacks a person's central nervous system , leading to demyelination. Disease onset usually occurs in young adults, and it is more common in females...

, as a cerebellar symptom (including ataxia, intentional tremor & dysarthria

Dysarthria

Dysarthria is a motor speech disorder resulting from neurological injury, characterised by poor articulation...

).

Presentation

It is commonly demonstrated 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 pronation

Pronation

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 feetThe 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.

Another method of testing for this condition is called the heel

Heel

The heel is the prominence at the posterior end of the foot. It is based on the projection of one bone, the calcaneus, behind the articulation of the bones of the lower leg. In the long-footed mammals, both the hoofed species and the clawed forms which walk on the toes , the heel is well above the...

 to shin

Shin

Shin may refer to:* Shin In-Seob Korean footballer, currently playing for Adelaide United* Shinbone, the larger of the two bones in the leg below the knee in vertebrates* Shin Buddhism, a widely practiced branch of Buddhism...

 test. This is performed by having the patient in a supine

Supine position

The supine position is a position of the body; lying down with the face up, as opposed to the prone position, which is face down, sometimes with the hands behind the head or neck...

or sitting position. The heel of one foot is rubbed up and down the shin of the opposite leg in a rapid movement. (bates guide to physical examination) A positive sign of this condition would be that the patient was not able to perform this movement quickly or steadily, instead showing slow and wobbly movements.