Objective: Oral and verbal apraxias represent motor programming deficits of nonverbal and verbal movements respectively. Studying their properties may shed light on speech motor control processes. This study was focused on identifying cases with oral or verbal apraxia, their co–occurrences and severities.

Materials & Methods: In this non-experimental study, 55 left adult subjects with left brain lesion including 22 women and 33 men with age range of 23 to 84 years, were examined and videotaped using oral apraxia and verbal apraxia tasks. Three speech and language pathologists independently scored apraxia severities. Data were analyzed by independent t test, Pearson, Phi and Contingency coefficients using SPSS 12.

Results: Mean score of oral and verbal apraxias in patients with and without oral and verbal apraxias were significantly different (P<0.001). Forty- two patients had simultaneous oral and verbal apraxias, with significant correlation between their oral and verbal apraxia scores (r=0.75, P<0.001). Six patients showed no oral or verbal apraxia and 7 had just one type of apraxia. Comparison of co-occurrence of two disorders (Phi=0.59) and different oral and verbal intensities (C=0.68) were relatively high (P<0.001).

Conclusion: The present research revealed co-occurrence of oral and verbal apraxias to a great extent. It appears that speech motor control is influenced by a more general verbal and nonverbal motor control.