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Progressive apraxia of speech as a sign of motor neuron disease
Joseph R Duffy1, Richard K Peach, Edythe A Strand
1Division of Speech Pathology, Dept. of Neurology, Mayo Clinic, Rochester, MN 55905, USA. jduffy@mayo.edu
Purpose:
To document and describe in detail the occurrence of apraxia of speech (AOS) in a group of individuals with a diagnosis of motor neuron disease (MND).
Method:
Seven individuals with MND and AOS were identified from among 80 patients with a variety of neurodegenerative diseases and AOS (J. R. Duffy, 2006). The history, presenting complaints, neurological findings, and speech-language findings were documented for each case.
Results:
Spastic or mixed spastic-flaccid dysarthria was present in all 7 cases. The AOS was judged as worse than the dysarthria in 4 cases. Nonverbal oral apraxia was eventually present in all cases. Aphasia was present in 2 cases and equivocally present in another 2. Dementia was present in 1 case and equivocally present in 2.
Conclusions:
AOS can occur in MND, typically also with dysarthria, but not invariably with aphasia or other cognitive deficits. Thus, a diagnosis of MND does not preclude the presence of AOS. More importantly, MND should be a diagnostic consideration when AOS is a prominent sign of degenerative disease.
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