Question
Recently a patient was admitted to our rehabilitation department with a diagnosis of corticobasal degeneration. She presents with dysarthria, resembling that of ataxic dysarthria and mild apraxia (oral greater than verbal). Although her speech sounds abe
Answer
Corticobasal degeneration (also known as corticobasal ganglionic degeneration) is one of the parkinsonism-plus syndromes (PPS) which also include progressive supranuclear palsy (PSP), Shy-Drager syndrome, multiple system atrophy (MSA) and olivopontocerebellar degeneration. These diseases affect multiple neural systems and produce varying symptoms from patient to patient. All affect the basal ganglia to some extent, producing some symptoms similar to idiopathic Parkinson's disease (PD). In fact, patients may initially be diagnosed with PD with a diagnosis of PPS coming later as the disease progresses. Corticobasal degeneration is one of the rarer of the parkinsonism-plus syndromes and typically the progression of symptoms is more rapid than those seen in PD. Unlike PD, patients with corticobasal degeneration typically do not respond to antiparkinsonism drugs. Dementia is also seen in the later stages of the syndrome. The dysarthria associated with corticobasal degeneration is of the mixed variety and varies from patient to patient.
With regard to treatment, there is very little research investigating the effectiveness of behavioral therapy with patients with this specific diagnosis. Because the components of the mixed dysarthria may vary, a clinician could identify the primary dysarthria and use treatments that have been designed for that type of dysarthria. For example, speaking rate control techniques or other prosodic therapies for patients with predominately ataxic symptoms. Countryman, et al (1994) did provide some evidence that Lee Silverman Voice Therapy LSVT is effective in improving voice and intelligibility in patients with parkinsonism-plus syndromes, but caution that it should only be used in patients who have voice symptoms typical of PD. However, as this disease often shows rapid progression, it is likely that speech will also show rapid deterioration. With this in mind, a speech therapy program should be simple and target functional communication as quickly and efficiently as possible. It may be more beneficial to spend therapy time teaching the patient ways to compensate for speech deficits, as well as repair strategies to use when intelligibility breaks down, as well as working with family members to assure maximum communicative effectiveness. An excellent resource is Management of Speech and Swallowing in Degenerative Disorders by Yorkston, Miller and Strand. All patients with dysarthria, regardless of etiology, can benefit from these communication-centered approaches to therapy to improve their quality of life. Patients who receive speech therapy in early stages of the disease progression may be able to continue to communicate verbally for a longer period of time. Augmentative communication will likely be necessary in later stages.
Dr. Nancye Roussel is an Assistant Professor in the Dept. of Communicative Disorders at the University of Louisiana, Lafayette. She is a certified speech-language pathologist and has practiced in both hospital and school settings prior to her employment at the University. She currently coordinates the clinical practicum in voice at the University in addition to her teaching responsibilities. Dr. Roussel has taught a graduate course in dysphagia for the past 12 years. In addition, she teaches graduate courses focusing on motor speech disorders in adults and children, voice disorders, and speech science.
