Progressive apraxia of speech as a sign of motor neuron disease.
OBJECTIVE
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).


METHODS
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.
Division of Speech Pathology, Dept. of Neurology, Mayo Clinic, Rochester, MN 55905, USA. jduffy@mayo.edu
Joseph R
JR
Duffy
Richard K
RK
Peach
Edythe A
EA
Strand
D000368:Aged; D000369:Aged, 80 and over; D001072:Apraxias / Q000175:diagnosis* / Q000209:etiology*; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology; D018450:Disease Progression; D004401:Dysarthria / Q000175:diagnosis / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016472:Motor Neuron Disease / Q000150:complications* / Q000175:diagnosis*; D012189:Retrospective Studies