Abnormal emotional word ratings in Parkinson's disease.

Blunted facial expressions and diminished expressions of emotional prosody associated with Parkinson's disease (PD) could be attributed to motor rigidity/akinesia. Although impaired recognition of emotional faces and prosody in PD suggests emotional dysfunction is not entirely motor-efferent, comprehension might depend upon imitation with motor feedback. Thus, to learn if patients with PD have an emotional conceptual defect, we examined their ratings for the emotional connotations of words on a 1-9 scale for valence and arousal. When compared to control participants the valence (positive-negative) and arousal (excited-calm) ratings of the PD patients were blunted, but their ratings of the control expense words (expensive-cheap) were not. These blunted emotion ratings suggest that patients with PD have a degradation of their emotional conceptual-semantic system.

Non-random distribution of spermatogonia in rats: evidence of niches in the seminiferous tubules.

The relationships and distribution of spermatogonia were studied as a function of the stage of the seminiferous epithelium cycle in rats. Primitive spermatogonia in the mouse are located along regions of the basal lamina that face the interstitium. Before studying the distribution of spermatogonia in rats, it was necessary to characterize the various types of spermatogonia, as recently performed for mice. The Strauss' linear index (Li) selectivity method was then used and spermatogonia of the A(single) (A(s)) to A(aligned) (A(al)) lineage were preferentially found to be located in regions opposing the interstitium at stages V, VII and IX of the spermatogenic cycle. Because relatively little tubule-to-tubule contact occurs in rats, the aim of this study was to determine whether tubule-to-tubule contact or tubule proximity (or alternatively, the amount of interstitium) was an important factor in spermatogonial position. In this regard, another method (tubule proximity) was devised to determine spermatogonial position that accounted for the presence of adjacent tubules. This method showed that the position of tubules, rather than tubule contact, was more accurate than the Li method in determining the location of spermatogonia in the rat. The results also showed a non-random distribution of spermatogonia resembling that of the mouse, and that tubule-to-tubule contact is not essential for the positioning of spermatogonia. In conclusion, the results of this study strongly indicate that the most primitive type A spermatogonia (A(s), A(paired) and A(al)) in rats are present in niches located in those areas of the seminiferous tubules that border the interstitial tissue.

Effects of bromocriptine in a patient with crossed nonfluent aphasia: a case report.

OBJECTIVE: Because studies have shown some positive effects of the dopaminergic agent bromocriptine for improving verbal production in patients with nonfluent aphasia, we examined its effect in a patient with an atypical form of crossed nonfluent aphasia from a right hemisphere lesion. DESIGN: Open-label single-subject experimental ABAB withdrawal design. PATIENT: A right-handed man who, after a right frontal stroke, developed nonfluent aphasia, emotional aprosodia, and limb apraxia. INTERVENTION: Escalating doses up to 20mg of bromocriptine in 2 separate phases. MAIN OUTCOME MEASURES: We measured verbal fluency (words/min in discourse, Thurstone letter fluency), expression of emotional prosody, and gesture production. RESULTS: The patient showed substantial improvement in both verbal fluency measures and no significant improvement in gesture or emotional prosody. Verbal fluency improvements continued in withdrawal phases. CONCLUSIONS: Our results are less likely caused by practice or spontaneous recovery because we observed little improvement in emotional prosody and gesture tasks. Verbal fluency improvements during treatment and withdrawal phases suggest that the effects of bromocriptine may be long-lasting in its influence on the neural networks subserving verbal initiation.

Conceptual apraxia in probable Alzheimer's disease as demonstrated by the Florida Action Recall Test.

Patients with probable Alzheimer's disease (AD) often have difficulties associated with semantic knowledge. Therefore, conceptual apraxia, a defect of action semantics and mechanical knowledge, may be an early sign of this disease. The Florida Action Recall Test (FLART), developed to assess conceptual apraxia, consists of 45 line drawings of objects or scenes. The subject must imagine the proper tool to apply to each pictured object or scene and then pantomime its use. Twelve participants with Alzheimer's disease (NINCDS-ADRDA criteria) and 21 age- and education-matched controls were tested. Nine Alzheimer's disease participants scored below a 2-standard-deviation cutoff on conceptual accuracy, and the three who scored above the cutoff were beyond a 2-standard-deviation cutoff on completion time. The FLART appears to be a sensitive measure of conceptual apraxia in the early stages of Alzheimer's disease.

Frontal-opercular aphasia.

The standard nomenclature divides nonfluent aphasic syndromes with relatively spared comprehension into Broca's aphasia and transcortical motor aphasia. We report on a patient with a persistent nonfluent aphasia from a discrete, primarily cortical, frontal-opercular lesion who had impaired syntax but intact repetition and, therefore, did not conform to the traditional classification. Based on this patient's behavior and a review of other cases, we have divided the nonfluent aphasias with intact comprehension into five disorders. (1) Verbal akinesia-exhibiting diminished intention or drive to speak and associated with medial frontal lesions (supplementary motor area and cingulate gyrus) or with lesions damaging the efferent projections from these areas. (2) Disorders of syntax-telegraphic and agrammatic utterances that may be associated with dominant pars opercularis lesions. (3) Phonemic disintegration-a failure to correctly produce phonemes, which may be associated with injury to the opercular primary motor cortex or efferent projections from this area. (4) Defects of lexical access-patients who struggle to find words and are impaired at timed word-generation tasks. Defects of lexical access may be associated with lesions of the pars triangularis and adjacent prefrontal cortex. (5) Mixed defects. According to this model, the traditional patient with Broca's aphasia would exhibit disorders of syntax, phonemic disintegration, and defects of lexical access, whereas the traditional patient with transcortical motor aphasia would have verbal akinesia or defects of lexical access or both. Our patient had defects of lexical access and syntax, but only mild symptoms of phonemic disintegration, suggesting that his opercular primary motor cortex was relatively intact. Our patient's ability to repeat normally while his propositional speech remained telegraphic suggests that different neural mechanisms subserve these functions.

Ideomotor apraxia in Alzheimer disease and left hemisphere stroke: limb transitive and intransitive movements.

OBJECTIVE: Ideomotor apraxia was studied in patients with Alzheimer disease (AD) and unilateral left hemispheric damaged (LHD) stroke to determine whether these groups differed. BACKGROUND: Given that the neuropathology of AD is bilateral and more diffuse than the localized involvement in patients after an LHD stroke, and given that the cognitive deficits in AD are more widespread than in LHD stroke, the authors predicted that patients with these disorders would differ in response to an auditory command task administered to evaluate ideomotor apraxia, and that the two patient groups would be significantly more impaired than healthy matched control subjects. METHODS: Twenty-one persons were studied, including equal numbers of patients with AD, patients with unilateral LHD stroke, and control subjects. An auditory command test of limb apraxia was administered and videotaped to score performance and to code spatial-temporal or content errors. RESULTS: The patients with AD and LHD stroke were significantly more impaired than healthy control subjects. Whereas the patients with AD and LHD stroke were equally apraxic and did not differ in their performance of transitive limb movements, the patients with AD were significantly more impaired than the patients with stroke when performing intransitive limb movements. A positive correlation was found between severity of dementia and severity of apraxia in the patients with AD. The patients with LHD stroke were as likely to make spatial-temporal as content errors when performing intransitive limb movements, whereas the patients with AD made content errors only. Error types produced with transitive limb movements did not differ between groups; spatial-temporal errors were the most common errors made both by patients with AD and patients with LHD stroke. CONCLUSIONS: As predicted, patients with AD and with LHD stroke were impaired when producing limb movements after auditory command, and both patient groups were significantly more impaired than the healthy adults. Patients with AD were significantly more impaired than patients with stroke when performing intransitive limb movements, and error types differed by group. Patients with AD and patients with stroke were equally impaired when performing transitive movements, and error types did not differ by group. Patients with ideomotor apraxia are often degraded in their production of transitive and intransitive movements, and the observation that performance may differ depending on the type of limb movement suggests that movement representations for transitive and intransitive movements may be at least partially independent.

Crossed apraxia: implications for handedness.

Liepmann posited that right hand preference relates to left hemisphere dominance for learned skilled movements. Limb apraxia, impairment of skilled movement, typically occurs in individuals with left hemisphere (LH) lesions. The occurrence of apraxia in right-handed individuals following right-hemisphere lesions appears to refute Liepmann's hypothesis. We studied the apraxia of a right-handed man, RF, following a right frontal lesion to determine whether his apraxia paralleled the apraxia seen following LH lesions. Results of behavioral testing indicated that, like individuals with apraxia following left frontal lesions, RF was better at gesture recognition than gesture production which was significantly impaired across tasks. Kinematic motion analyses of movement linearity, planarity, and the coupling of temporospatial aspects of movements substantiated the parallel impairments in RF and patients with LH apraxia. The impairment seen in our patient with crossed apraxia provides evidence for the fractionation of systems underlying hand preference and skilled movement.

Spared comprehension of emotional prosody in a patient with global aphasia.

BACKGROUND: Several studies have demonstrated that patients with right hemisphere damage, when compared with left-hemisphere damaged controls, are impaired at comprehending emotional prosody. Critics of these studies, however, note that selection may have been biased because left-hemisphere-damaged subjects had good verbal comprehension. OBJECTIVE: To learn whether a subject with a large left hemisphere stroke and global aphasia could comprehend emotional prosody in spoken material. METHOD: The authors formally tested speech and language with the Western Aphasia Battery and comprehension of emotional prosody and emotional facial expression with the Florida Affect Battery. RESULTS: The patient could not perform verbally mediated tests but demonstrated spared ability to match emotional prosody to emotional facial expressions under a variety of conditions. CONCLUSIONS: These observations further support the idea that verbal and emotional communication systems are independent and mediated by different hemispheres.

Articulatory processes and phonologic dyslexia.

BACKGROUND/OBJECTIVE: Grapheme-to-phoneme conversion (GPC) allows the pronunciation of nonword letter strings and of real words with which the literate reader has no previous experience. Although cross-modal association between visual (orthographic) and auditory (phonemic-input) representations may contribute to GPC, many cases of deep or phonologic alexia result from injury to anterior perisylvian regions. Thus, GPC may rely upon associations between orthographic and articulatory (phonemic-output) representations. METHOD/RESULTS/CONCLUSION: Detailed analysis of a patient with phonologic alexia suggests that defective knowledge of the position and motion of the articulatory apparatus might contribute to impaired transcoding from letters to sounds.

Object and action naming in Alzheimer's disease.

We administered measures of object naming and action naming to matched groups of ten patients with Alzheimer's disease (AD) and ten normal control subjects. AD patients were impaired in both object and action naming, with object naming impaired to a significantly greater extent than action naming. This difference remained after controlling for the effects of word frequency. We propose that the pattern of pathological changes in AD impairs both conceptual and lexical retrieval systems for objects but only conceptual systems for actions. The similar patterns of error during the two tasks suggest quantitative rather than qualitative differences in the breakdown of the two abilities.

The significance of body part as tool errors in limb apraxia.

When pantomiming to command, individuals with left hemisphere brain damage (LBD) often produce errors in which they use a body part as if it were the tool (BPT). Some clinicians question the significance of this type of error because subjects without brain damage at times also make BPT responses. We analyzed BPT errors in LBD and normal subjects who were reinstructed to modify the inappropriate BPT responses when they occurred. We also analyzed errors in normal subjects who were never reinstructed if a BPT occurred. Whereas LBD subjects who were reinstructed produced significantly more BPT errors than normals who were also reinstructed, LBD subjects were not different from normals who were not reinstructed. When reinstructed, normal control subjects correctly modified virtually all BPT errors, whereas LBD subjects did not modify BPT errors. These findings underscore the need for reinstruction when a BPT error occurs to determine whether it represents a true BPT error, a sign of limb apraxia.

Cognitive neuropsychological analysis and neuroanatomic correlates in a case of acute anomia.

We describe an analysis of lexical processing performed in a patient with the acute onset of an isolated anomia. Based on a model of lexical processing, we evaluated hypotheses as to the source of the naming deficit. We observed impairments in oral and written picture naming and oral naming to definition with relatively intact semantic processing across input modalities, suggesting that output from the semantic system was impaired. In contrast to previous reports, we propose that this pattern represents an impairment that arises late in semantic processing prior to accessing mode-specific verbal and graphemic output lexicons. These deficits were associated with a lesion in the posterior portion of the middle temporal gyrus or area 37, an area of supramodal association cortex that is uniquely suited as a substrate for the multimodal deficit in naming.

Lexical-semantic deficits in two patients with dominant thalamic infarction.

Two patients with dominant thalamic infarction, one in the tuberothalamic artery territory, the other in the paramedian artery territory, demonstrated language impairment limited to word retrieval difficulties in spontaneous language and structured naming tasks. Using a cognitive neuropsychological model of lexical processing developed in the study of patients with cortical lesions. We carried out a detailed investigation of their lexical abilities. Both patients demonstrated impairment restricted to oral and written picture naming and oral naming to definition and spared performance on tasks of lexical comprehension, oral word reading, and writing to dictation, as well as syntactic comprehension and production. Naming impairment disproportionately affected lower frequency words, and word substitutions often corresponded to objects that were semantically-related to target words. We propose that our patients' word retrieval impairments reflect a failure of thalamic input to effectively engage the cortical networks subserving lexical semantic processing, leading to degraded levels of activation as the semantic system interfaces with subsequent stages of lexical processing.

Reading lexically without semantics: evidence from patients with probable Alzheimer's disease.

Recent modifications of the lexical model of oral reading make the prediction that under conditions where sublexical reading processes alone cannot achieve the target pronunciation (i.e., when words have exceptional spellings or when sublexical processes are impaired), patients with severe semantic impairment should have more difficulty reading aloud semantically impaired words than semantically retained words. In a battery of lexical-semantic and reading tasks, two neurologically normal control subjects and two subjects with probable Alzheimer's disease (AD) and only moderate semantic impairment read aloud all words accurately. One AD subject with severe semantic impairment was impaired in word reading but demonstrated no difference in reading words with regular and exceptional spellings. Another AD subject with severe semantic impairment read aloud without error virtually all regular and exception words. Neither severely impaired AD subject demonstrated any relationship between oral reading accuracy and semantic knowledge of exception words. These findings support a model of word reading incorporating lexical, nonsemantic processes by which lexical orthographic input representations directly activate lexical phonological output representations without the necessity of semantic mediation.

Gesture laterality in aphasic and apraxic stroke patients.

Limb preference during conversational gestures may be a reflection of functional hemispheric asymmetries. In right-handers, speech and praxis are usually mediated by the left hemisphere and in conversation, right-handers gesture more with their right than left hand. However, patients with left hemisphere brain damage, who are aphasic and apraxic but not hemiplegic, may use their right hemisphere to compensate for their left. Therefore, we investigated spontaneous lateralized gesture production during conversation in a group of left hemisphere-damaged stroke patients, who were aphasic and apraxic but not hemiparetic, and compared their performance to a group of matched controls. Whereas the control group had a strong right-hand preference, the nonparetic but apraxic and aphasic stroke patients were as likely to produce gestures with the right, left, or both hands.

Ecological implications of limb apraxia: evidence from mealtime behavior.

Humans learn skilled acts in order to effectively interact with their environment. A loss of the ability to perform skilled acts is termed apraxia. Apraxia has been thought to be of theoretical interest, but the ecological implications of apraxia are controversial and have not been fully studied. We examined ten patients with unilateral left hemisphere cerebral infarctions (eight of whom were apraxic) and compared their mealtime eating behavior to a group of neurologically normal, age-matched controls. The stroke patients were less efficient in completing the meal. They made more action errors and were less organized in the sequencing of mealtime activities. Because the patients made more errors while using tools than when performing nontool actions, their deficit could not be accounted for by an elemental motor deficit. A positive relationship was found between mealtime action errors and the severity of apraxia. These findings suggest that limb apraxia may adversely influence activities of daily living.

The role of cognitive models in language rehabilitation.

Recently, researchers have advocated the use of cognitive neuropsychological models as an infrastructure for efforts in language rehabilitation. In this approach, clinicians characterize language impairments in individual patients with respect to cognitive models of lexical and sentence processing. This approach contrasts with many earlier efforts in which evaluation and treatment focused on the presence or absence of aphasia viewed as a general language impairment, or on syndromes of aphasia. We consider the structure that cognitive neuropsychological models may provide in different portions of the rehabilitation process and find that this approach, when applied with methodological rigor, has practical implications for practice in aphasia assessment and treatment. In turn, some hope that data derived from clinical applications with this approach may support the modification of cognitive neuropsychological models.