Patterns of dystonia ("I-D-I" and "D-I-D-") in response to l-dopa therapy for Parkinson's disease.

The clinical, biochemical, and pharmacologic responses to L-dopa were studied in 87 patients with Parkinson's disease. Eleven of the 87 patients had a long-duration response, 39 had a short-duration response, and 37 had a combination of both. Thirty-four of the 39 patients with short-duration response to L-dopa experienced a consistent and reproducible sequence of clinical and biochemical events after each dose, characterized by improvement of parkinsonism and a single phase of dystonia occurring during or shortly after the peak of dopa concentration in plasma and during maximal clinical improvement. We have called this the I-D-I- response, for Parkinsonism-Improvement-Dystonia-Improvement-Parkinsonism. The remaining five patients all had the onset of the disease at an unusually young age and showed a distinctly different response pattern consisting of a first phase of dystonia, before there was any improvement, followed by a phase of improvement without dystonia and then by a second phase of dystonia before the abrupt return of parkinsonism. We have called this the D-I-D response, for Parkinsonism-Dystonia-Improvement-Dystonia-Parkinsonsim. Dystonia occurs in the D-I-D- response when the concentration of dopa in plasma passes through a critical but relatively low level, whereas it remains absent as long as the concentration of dopa remains above that level. In the I-D-I- response, dystonia is avoided by keeping the plasma concentration of dopa low, in the D-I-D- response by keeping it high. It is postulated that in the D-I-D response postsynaptic depolarization blockade due to supramaximal stimulation of the neuronal system mediating dystonia occurs, whereas in the I-D-I response the postsynaptic members of the same neuronal population respond with excitation but not with depolarization blockade.

The effect of auditory rhythmic stimulation on articulatory accuracy in apraxia of speech.

In order to study the effects of different rates of rhythmic auditory stimulation on the phonemic accuracy of speakers who have apraxia of speech, eight apraxic subjects read four equated monosyllabic passages under one control and three experimental conditions. In the experimental conditions, rhythmic auditory stimulation provided by a metronome was imposed at each subject's oral reading rate as well as 75% and 125% of this established rate. In the control condition, the subjects read without any accompanying rhythmic stimulation. It was found that the stimulus supplied by an auditory metronome did not significantly improve the phonemic accuracy of these subjects. Articulatory accuracy tended to deteriorate under imposed rhythmic stimulation.

Phonemic behavior of aphasic subjects without dysarthria or apraxia of speech.

Thirty adult aphasic subjects without apraxia of speech or dysarthria were tested for their ability to produce phonemes in single test words and in spontaneous contextual speech. Results indicated that 75% of the total phonemic errors were due to a whole-word phenomenon apparently associated with faulty processing of the word rather than faulty production of the phoneme. True phonemic errors comprised 25% of the total errors or about 2% of all responses. Phoneme substitutions were by far the most frequent error (61%). Of the 30 subjects, 28 made no phonemic errors in spontaneous contextual speech. Aphasic behavior is not characterized by significant breakdown of articulatory performance. Observed patterns of error do not clearly support a phonemic regression hypothesis.

Nonspeech and speech processing skills in patients with aphasia and apraxia of speech.

Nonspeech and speech auditory processing skills as well as internal speech processing skills were assessed among four patients with acquired "pure" apraxia of speech, 10 with acquired aphasia, 10 with aphasia plus apraxia of speech, and 11 neurologically normal adults. Fourteen tasks were administered and performances on 68 variables were examined using both nonparametric and parametric analyses controlling for the effects of advancing age and associated hearing loss. In all cases, the "pure" apractic patients performed as normal subjects. Few differences were noted among the performances of the aphasic and aphasic-apractic subjects. Results led to three major conclusions: (1) apraxia of speech is a disorder distinct from aphasia; (2) aphasic individuals, despite locus of lesion, demonstrate disabilities for processing nonspeech and speech materials presented auditorily and for analytically evaluating speech evoked internally; and (3) aphasic individuals demonstrating similar severity levels of language impairment show similar performance patterns for these types of processing tasks, despite locus of lesion or coexistence of apraxia of speech.

Effect of prestimulation on sentence comprehension by aphasic subjects.

Aphasic subjects and controls were tested to determine whether comprehension of spoken sentences was enhanced by prestimulation concerning their contents. For each of the 20 test points, the subject listened to the test sentence and selected the corresponding picture from among four pictures presented simultaneously. The preparatory suggestions were given in one test condition and withheld in the other. Each prestimulation consisted of one or two sentences that indicated the persons, objects, or general situation to be presented in the test sentence. Analysis of variance indicated that the effect of the prestimulation was not significant.

"Tuning in" and "fading out": performance of aphasic patients on ordered PICA subtests.

Performance of 182 aphasic patients was examined on 11 PICA subtests for which the order of presentation of items is specified in an attempt to determine possible "tuning in" and "fading out" behavior. Results indicate that these phenomena occur as measurable patterns, which are to some degree dependent on the severity of aphasia as measured by each patient's overall PICA percentile.

The influence of context on the auditory comprehension of paragraphs by aphasic subjects.

Subjects were exposed to two sets of paragraphs that probed their auditory comprehension abilities under various prestimulation conditions. In Experiment 1, aphasic and control subjects listened to four paragraphs. Each paragraph was preceded by a control condition (no antecedent) or one of the following contextual antecedents: picture, verbal, or picture and verbal combined. Prestimulation with a picture alone was detrimental, but prestimulation with a picture used in combination with a verbal context appeared to be of value. In Experiment 2, subjects heard four paragraphs that were less cohesive than those in Experiment 1. Only verbal and control conditions were contrasted. The provision of prior verbal contexts facilitated the auditory comprehension of the paragraphs.

Effect on phoneme duration control of three utterance-length conditions in an apractic patient.

Phoneme duration control in utterances of various lengths was investigated in one apractic subject. Results indicate a loss of segment duration control and a speeding of intrasyllabic articulatory rates in apraxia. Findings are related to a theory of apractic speech dysfunction.

Effect of auditory prestimulation on naming in aphasia.

In five aphasic subjects, picture naming alone was compared with picture naming in the presence of four different auditory cues. Eighty words represented by pictures were associated with the following auditory cues: the first phoneme of the target word; an open-ended sentence designed to elicit the target word; three words, one of which was the target word; three words, all semantically related to the target word. Three conditions--the phonetic cue, the open-ended sentence, and the set of three words containing the target word--facilitated naming significantly. The condition making use of semantically related words resulted in a significant decrease in naming performance. Implications of these findings for theories of verbal recall, impairment of verbal recall in aphasia, and language therapy are discussed.

Prediction of PICA overall score by short versions of the test.

Two short versions (SPICAs) of the Porch Index of Communicative Ability (PICA) were developed and investigated, with specific attention to their ability to predict standard PICA overall scores of patients with aphasia. Ninety-three patients were administered three versions of the test in randomized order. Results indicate that SPICAs predict overall scores by standard administration at acceptable confidence levels in approximately one-third of the time required for the administration of the standard PICA.

Patterns of dysfunction in schizophrenic patients on an aphasia test battery.

Twenty-seven schizophrenic patients free of any known neurologic deficit were tested with an aphasia test battery. The objective of the research was to derive a profile of schizophrenic language performance to permit its comparison with the profiles characteristic of aphasia, apraxia of speech, generalized intellectual impairment, and confused language. Results indicate that schizophrenic patients exhibit a profile of language performance distinctive from those found in aphasia, apraxia of speech, confusion, or generalized intellectual impairment and demonstrate that the disruption of language in schizophrenia is not aphasic in nature.