Dopamine Function in Developmental Stuttering

INCLUSION AND EXCLUSION CRITERIA - STUTTERING AND CONTROL SUBJECTS: Subjects must be between the ages of 18 and 55. Subjects must be in good general health except for the primary neurological diagnosis of stuttering. Subjects may not have evidence of hypertension or cardiovascular disease, cerebrovascular disease or hyperthyroidism. EKG and thyroid function tests must be within normal limits. Subjects must have no history of traumatic head injury including any head trauma that resulted in loss of consciousness or history of substance abuse, including alcohol (excluding caffeine). Subjects will be screened for history of psychiatric illness, such as depression, anxiety or obsessive-compulsive disorders according to DSM-IV; subjects with such diagnoses will be excluded. Subjects will be screened for a past medical history or family history of speech-language disorders; subjects with a personal or significant family history of speech-language disorders unrelated to the diagnoses of stuttering or aphasia will be excluded. Also those subjects with immediate family members having a significant history of heart attack or stroke will be excluded. Women who are pregnant or currently breast-feeding will be excluded from this study. Subjects with pacemakers, aneurysm clips, cochlear implants, shrapnel fragments or have a significant history of exposure to small metallic objects, which might have become lodged in the tissues of the head, or neck will be excluded due to the MRI. The following criteria must be met to identify an individual who stutters: Affected individual regards him or herself as having a stuttering disorder, reporting instances during speech where they know exactly what they wish to say, but can not be due to production impairment; these instances may be accompanied by a feeling of tension somewhere within the vocal tract. Individuals may have sought treatment for their stuttering. Speech-language pathologist confirms diagnosis of stuttering disorder in affected individuals, documenting presence of silent or sound prolongations, syllable repetitions, word/phrase repetitions, interjections and pauses at non-linguistic loci in their speech. Affected individuals will be at least 5% dysfluent in at least 2 of the speaking tasks used to assess fluency. Recovered stutterers must have a history of stuttering documented by the speech pathologist responsible for evaluation or treatment of this individual during childhood. A history of stuttering may alternatively be documented by a parent and at least one other family member or friend. Recovered individuals must report that they no longer monitor their speech on a routine basis or use speech therapy techniques while speaking. Speech-language pathologist must judge that recovered individuals are currently free of overt stuttering (less than 1 stuttering behavior/100 words). Onset of stuttering in both affected individuals and recovered stutterers must have occurred in childhood (between 3 and 10 years-of-age), unrelated to psychological or neurological trauma.