The spatial distribution of perseverations in neglect patients during a nonverbal fluency task depends on the integrity of the right putamen.

Deficient inhibitory control leading to perseverative behaviour is often observed in neglect patients. Previous studies investigating the relationship between response inhibition and visual attention have reported contradictory results: some studies found a linear relationship between neglect severity and perseverative behaviour whereas others could not replicate this result. The aim of the present study was to shed further light on the interplay between visual attention and response inhibition in neglect, and to investigate the neural underpinnings of this interplay. We propose the use of the Five-Point Test, a test commonly used to asses nonverbal fluency, as a novel approach in the context of neglect. In the Five-Point Test, participants are required to generate as many different designs as possible, by connecting dots within forty rectangles. We hypothesised that, because of its clear definition of perseverative errors, the Five-Point Test would accurately assess both visual attention as well as perseverative behaviour. We assessed 46 neglect patients with right-hemispheric stroke, and performed voxel-based lesion-symptom mapping (VLSM) to identify neural substrates of perseverative behaviour as well as the spatial distribution of perseverations. Our results showed that the Five-Point Test can reliably measure neglect and perseverative behaviour. We did not find any significant relationship between neglect severity and the frequency of perseverations. However, within the subgroup of neglect patients who displayed perseverative behaviour, the spatial distribution of perseverations significantly depended on the integrity of the right putamen. We discuss the putative role of the putamen as a potential subcortical hub to modulate the complex integration between visual attention and response inhibition processes.

Limb-kinetic apraxia affects activities of daily living in Parkinson's disease: a multi-center study.

BACKGROUND AND PURPOSE: Impaired dexterity (fine hand movements) is often present in Parkinson's disease (PD), even at early to moderate disease stages. It has a detrimental impact on activities of daily living (ADL) such as buttoning, contributing to reduced quality of life. Limb-kinetic apraxia, a loss of the ability to make precise, independent but coordinated finger and hand movements, may contribute to impaired dexterity even more than bradykinesia per se. However, the impact of limb-kinetic apraxia on ADL remains controversial. Our aim was to identify the strongest predictor of buttoning and unbuttoning in PD. It was hypothesized that coin rotation (a surrogate of limb-kinetic apraxia) represents the most important determinant. METHODS: Sixty-four right-handed, early to moderate PD patients were recruited from three movement disorder centers (Hoehn andYahr stages 1-3). Buttoning, unbuttoning and coin rotation (right and left hand) represented the target tasks. Motor impairment was assessed according to the Unified Parkinson's Disease Rating Scale. RESULTS: Multiple linear regression analysis showed that coin rotation with the right hand was the only significant predictor of buttoning (P < 0.001) and unbuttoning (P = 0.002). Notably, measures of bradykinesia or overall motor impairment did not represent significant predictors. CONCLUSIONS: Constituting the novel key finding, limb-kinetic apraxia seems to be particularly relevant for ADL requiring dexterity skills in PD, even at early to moderate disease stages. Our results prompt research into the pathophysiological background and therapeutic options to treat limb-kinetic apraxia. The simple coin rotation test provides valuable information about ADL-related dexterity skills.

Screening for Language Disorders in Stroke: German Validation of the Language Screening Test (LAST).

BACKGROUND: Screening of aphasia in acute stroke is crucial for directing patients to early language therapy. The Language Screening Test (LAST), originally developed in French, is a validated language screening test that allows detection of a language deficit within a few minutes. The aim of the present study was to develop and validate two parallel German versions of the LAST. METHODS: The LAST includes subtests for naming, repetition, automatic speech, and comprehension. For the translation into German, task constructs and psycholinguistic criteria for item selection were identical to the French LAST. A cohort of 101 stroke patients were tested, all of whom were native German speakers. Validation of the LAST was based on (1) analysis of equivalence of the German versions, which was established by administering both versions successively in a subset of patients, (2) internal validity by means of internal consistency analysis, and (3) external validity by comparison with the short version of the Token Test in another subset of patients. RESULTS: The two German versions were equivalent as demonstrated by a high intraclass correlation coefficient of 0.91. Furthermore, an acceptable internal structure of the LAST was found (Cronbach's α = 0.74). A highly significant correlation (r = 0.74, p < 0.0001) between the LAST and the short version of the Token Test indicated good external validity of the scale. CONCLUSION: The German version of the LAST, available in two parallel versions, is a new and valid language screening test in stroke.

Short and valid assessment of apraxia in Parkinson's disease.

BACKGROUND: Valid assessment of apraxia in usually non-apraxic Parkinson's disease helps to delineate atypical parkinsonism frequently associated with apraxia. Furthermore, in a subgroup of late Parkinson's disease apraxia, typically the ideomotor subtype, may gradually superimpose onto parkinsonian motor symptoms contributing to defective manual skill. Here we evaluate the utility of a brief, standardized test, the apraxia screen of TULIA (AST). METHODS: Seventy five Parkinson's disease patients were tested with the AST. Parkinsonian motor deficits were measured using Movement Disorders Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part III and difficulties in activities of daily living (ADL) by modified MDS-UPDRS part II (eating, dressing, personal hygiene, and writing). RESULTS: No association was found between the AST and MDS-UPDRS part III, indicating that AST discriminates well (discriminative validity) between apraxia and parkinsonism. Furthermore, AST was associated with ADL and Hoehn & Yahr stage (convergent validity). CONCLUSIONS: AST is a short and valid test to rule out or detect apraxia in Parkinson's disease.

Impaired finger dexterity in Parkinson's disease is associated with praxis function.

A controversial concept suggests that impaired finger dexterity in Parkinson's disease may be related to limb kinetic apraxia that is not explained by elemental motor deficits such as bradykinesia. To explore the nature of dexterous difficulties, the aim of the present study was to assess the relationship of finger dexterity with ideomotor praxis function and parkinsonian symptoms. Twenty-five patients with Parkinson's disease participated in the study. Their left and right arms were tested independently. Testing was done in an OFF and ON state as defined by a modified version of the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS). Finger dexterity was assessed by a coin rotation (CR) task and ideomotor praxis using a novel test of upper limb apraxia (TULIA), in which the patients were requested to imitate and pantomime 48 meaningless, as well as communicative and tool-related gestures. Coin rotation significantly correlated with TULIA irrespective of the motor state and arm involved, but not with the MDS-UPDRS. This association was significantly influenced by Hoehn and Yahr stage. The strong association of finger dexterity with praxis function but not the parkinsonian symptoms indicates that impaired finger dexterity in Parkinson's disease may be indeed apraxic in nature, yet, predominantly in advanced stages of the disease when cortical pathology is expected to develop. The findings are discussed within a cognitive-motor model of praxis function.

A new bedside test of gestures in stroke: the apraxia screen of TULIA (AST).

BACKGROUND: Apraxia in patients with stroke may be overlooked, as clumsiness and deficient gestural communication are often attributed to frequently coexisting sensorimotor deficits and aphasia. Early and reliable detection of apraxia by a bedside test is relevant for functional outcome in patients with stroke. The present study was aimed at constructing a new bedside screening test for apraxia, called the Apraxia Screen of TULIA (AST), based on the comprehensive standardised Test for Upper-Limb Apraxia (TULIA). METHODS: First, an item-reduction analysis of the TULIA (48 gestures) was performed, based on the methods of classical test theory and on a larger sample of patients with stroke (n=133) and matched healthy controls (n=50). Stepwise elimination of items resulted in a set of 12 items, demonstrating high internal consistency (Cronbach alpha=0.92). The six-point scoring method of the TULIA was dichotomised to the score levels pass and fail. In the second part of this study the validity of the AST was assessed prospectively in a new cohort of patients with stroke (n=31) by using the Pearson correlation analysis and binary classification display with the TULIA. RESULTS AND DISCUSSION: Validation of the 12-item AST with the TULIA showed a remarkable diagnostic reliability with high specificity, sensitivity and positive predictive value, for the presence and severity of apraxia. The AST is shown to be a reliable and valid bedside test in patients with stroke, allowing a straightforward assessment of apraxia within a few minutes.

Comprehensive assessment of gesture production: a new test of upper limb apraxia (TULIA).

BACKGROUND: Only few standardized apraxia scales are available and they do not cover all domains and semantic features of gesture production. Therefore, the objective of the present study was to evaluate the reliability and validity of a newly developed test of upper limb apraxia (TULIA), which is comprehensive and still short to administer. METHODS: The TULIA consists of 48 items including imitation and pantomime domain of non-symbolic (meaningless), intransitive (communicative) and transitive (tool related) gestures corresponding to 6 subtests. A 6-point scoring method (0-5) was used (score range 0-240). Performance was assessed by blinded raters based on videos in 133 stroke patients, 84 with left hemisphere damage (LHD) and 49 with right hemisphere damage (RHD), as well as 50 healthy subjects (HS). RESULTS: The clinimetric findings demonstrated mostly good to excellent internal consistency, inter- and intra-rater (test-retest) reliability, both at the level of the six subtests and at individual item level. Criterion validity was evaluated by confirming hypotheses based on the literature. Construct validity was demonstrated by a high correlation (r = 0.82) with the De Renzi-test. CONCLUSION: These results show that the TULIA is both a reliable and valid test to systematically assess gesture production. The test can be easily applied and is therefore useful for both research purposes and clinical practice.