Neurologic Substrates of Motor Speech Disorders
A good clinical understanding of the neurologic substrates of neurologic communicative disorders is important both to diagnosis and treatment. This article briefly reviews neurologic substrates for motor speech disorders (MSD) and how clinicians may identify neurologic signs and symptoms to facilitate differential diagnosis of apraxia of speech (AOS) and the various types of dysarthria. Students and clinicians have numerous resources regarding general neuroanatomy and neurophysiology (e.g. Benarroch, 2006; Kandel, Schwartz, and Jessel, 1991; Nolte, 2002; Snell, 1997) as well as neuroanatomic correlates of speech-language behavior and disorders (Bhatnagar, 2012; Duffy, 2013). Articles on aspects of neuroimaging (Brown, Petersen and Schlaggar, 2003; Shuster, 2003) and neurologic substrates for MSDs (Farinella-Bocian, Strand, and Benarroch, 2007) are also available in previous editions of Perspectives. This article begins with an overview of the differing MSDs. A brief overview of neurologic systems is provided, followed by a more detailed description of the neurologic substrates for MSDs. Examples of clinical observations of speech and non-speech characteristics that can aid the clinician in understanding the underlying neural deficit are provided.