Ataxic cerebellum dysarthria is a sensorimotor speech disorder associated with damage to the cerebellum or its input and output pathways.¹
The cerebellums role in feed-forward processing has been linked to speech motor control. Neuro imaging studies led researchers Kristie Spencer and Dana Slocomb, Department of Speech and Hearing Sciences, University of Washington, Seattle, to establish two cerebellar cortical regions are responsible for the feedforward motor commands for speech: the anterior paravermal and superior lateral areas. Previously ataxic dysarthria had been classified as a disorder of motor execution, focusing on uncoordinated and hypotonic muscles.²
Motor nerve difficulties clearly contribute to ataxic dysarthria but this doesn’t address the processing abnormalities controlled by the cerebellum that take place during the planning phase of speech.
Difficulty in the pronunciation of words due to neurologic dysfunction of the nerves that control the facial muscles, tongue, lips, and throat present as a slurring of words or speaking slowly. If nerve palsies are also involved you may also have trouble controlling the muscles in your mouth and face.
The cranial nerves involved in the articulation of speech. These include:
• Trigeminal nerve (fifth cranial) supplies nerve function to the chewing muscles
• Facial nerve (seventh cranial) control facial muscles
• Hypoglossal nerve (twelfth cranial) controls the tongue
Updated: June 22,2018
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
¹Spencer, K.A. & Slocomb, D.L. Cerebellum (2007) 6: 58. https://doi.org/10.1080/14734220601145459
²Yorkston KM, Beukelman DR, Strand EA, Bell KA. Management of motor speech disorders in children and adults. 2nd ed. Austin: PRO-ED, Inc.; 1999.