Dysdiadochokinesia (DDK)

Superficial Siderosis Symptom Glossary

DDK is a symptom brought on by damage to the cerebellum and falls under the ataxia grouping.

The signs of Dysdiadochokinesia include changes in balance and gait, slow, awkward or rigid movements. A decline in the coordination of the arms, hands, or legs. Inarticulate or incomprehensible speech patterns and impairment of the ability to stop a directional movement and start the same action in the opposite direction.

For example, a person with DDK may have difficulty screwing or unscrewing a light bulb. They may also have a hard time repeating one to three syllables in a row quickly.

Your neurologist can perform simple in-office testing to evaluate DDK.

Rapidly Alternating Movement Evaluation

You’ll hold the palm of one hand on a flat surface (often the upper thigh), and then continuously flip the hand palm side up, then back to palm side down as fast as possible.

Point-To-Point Movement Evaluation

You’ll be asked to touch your nose and then, using the same finger and as quickly as possible, touch the outstretched finger of the person doing the test.

Heel-Shin Test

You’ll place one heel on one shin just below the knee, and then slide the heel down the shin to the foot. You should aim for rapid, coordinated movements.

Romberg Test

You’ll stand still with your heels together and your eyes closed. If you lose your balance in this position, you may have some form of DDK.

Gait Test

You’ll be asked to walk normally, and then walk heel to toe.

Updated: June 13, 2018

Sources: Superficial siderosis is a rare neurologic disease characterized by progressive sensorineural hearing loss, cerebellar ataxia, pyramidal signs, and neuroimaging findings revealing hemosiderin deposits in the spinal and cranial leptomeninges and subpial layer. The disease progresses slowly, and patients may present with mild cognitive impairment, nystagmus, dysmetria, spasticity, dysdiadochokinesia, dysarthria, hyperreflexia, and Babinski signs. Additional features reported include dementia, urinary incontinence, anosmia, ageusia, and anisocoria. Superficial siderosis MedGen UID: 831707 •Concept ID: CN226971 •Finding Orphanet: ORPHA247245
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