Dysdiadochokinesia
Dysdiadochokinesia | |
---|---|
Other names | Dysdiadochokinesis, dysdiadokokinesia, dysdiadokokinesis |
Specialty | Neurology |
Dysdiadochokinesia (DDK) is the medical term for an impaired ability to perform rapid, alternating movements (i.e., diadochokinesia). Complete inability is called adiadochokinesia. The term is from Greek δυς dys "bad", διάδοχος diadochos "working in turn", κίνησις kinesis "movement".[1]
Signs and symptoms
Abnormalities in diadochokinesia can be seen in the upper extremity, lower extremity and in speech. The deficits become visible in the rate of alternation, the completeness of the sequence, and in the variation in amplitude involving both motor coordination and sequencing.[2][3] Average rate can be used as a measure of performance when testing for dysdiadochokinesia.[4]
Dysdiadochokinesia is demonstrated clinically by asking the patient to tap the
Causes
Dysdiadochokinesia is a feature of cerebellar ataxia and may be the result of lesions to either the cerebellar hemispheres or the frontal lobe (of the cerebrum), it can also be a combination of both.[2] 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.[6]
Dysdiadochokinesia is also seen in Friedreich's ataxia and multiple sclerosis, as a cerebellar symptom (including ataxia, intention tremor and dysarthria). It is also a feature of ataxic dysarthria. Dysdiadochokinesia often presents in motor speech disorders (dysarthria), therefore testing for dysdiadochokinesia can be used for a differential diagnosis.[4]
Dysdiadochokinesia has been linked to a mutation in SLC18A2, which encodes vesicular monoamine transporter 2 (VMAT2).[7]
References
- ^ "dysdiadochokinesia". Farlex Partner Medical Dictionary. 2012.
- ^ S2CID 3198795.
- S2CID 19100385.
- ^ PMID 19088478.
- ^ Bates Guide to Physical Examination, 8th Ed.
- ^ "Dysdiadochokinesia", UBM Medica, United States. (2011). Retrieved May 11, 2011.
- PMID 23363473.