Drug treatment and familiar music aids an attention shift from vision to somatosensation in Parkinson's disease on the reach-to-eat task

Adaptive forgetting of place/object memory for dung in the domestic horse (Equus ferus caballus): Memory for a day

The domestic horse (Equus ferus caballus) makes dung deposits to form "stud-piles" and compulsively examines dung droppings, suggesting that dung contains species-relevant information. The present study investigates horses' use of location (place), odor (object) and memory for dung sniff encounters. Horses were video recorded in 2 indoor and 4 outdoor riding arenas as they were taken at different time intervals to experimenter-determined objects or dung deposits that they could sniff. Frame-by-frame video analysis measured approaches, sniff duration, nostril use, ear position and blinking associated with dung investigation. Horses approached and sniffed dung-deposits for longer duration than non-dung objects in all test locations. They made head movements across the extent of dung-deposits when sniffing, showed no nostril or ear preference directed to the target, and blinked as they disengage from sniffing. Reduced approach probability and sniff duration showed that they displayed good place/object memory for dung previously visited at similar and different locations on the same day but poor memory for dung visited on a previous day. Adaptive forgetting of object/place memory for dung after a previous day's dung visit may optimizes risk assessment, including the possibility of premature interruption of foraging by conspecifics.

Music Therapy in Parkinson's Disease

OBJECTIVES

Parkinson's disease (PD) is a chronic progressive neurologic disorder involving degeneration of the dopaminergic system. Its clinical manifestations include motor and nonmotor symptoms. Several nonpharmacologic therapies, such as music therapy (MT), have recently been developed in order to improve the clinical manifestations of this disease. The aim of this narrative literature review is to analyze the scientific evidence for the therapeutic effects of music in PD.

DESIGN

We undertook a search in the databases of PubMed, PsycINFO, Scopus, MEDLINE, and Science Direct.

SETTINGAND PARTICIPANTS

Inclusion criteria were articles including persons with PD rehabilitated with an MT intervention.

MEASURES

Keywords used were music therapy, Parkinson's disease, auditory cueing, non-motor symptoms, motor symptoms, and quality of life.

RESULTS

We detected a total of 27 articles, all of which analyzed the therapeutic effects of MT in PD. Of these, 20 studies analyzed the effects in motor symptoms (16 showed beneficial effects and 4, nonbeneficial effects); 9 studies analyzed the effects in nonmotor symptoms, 7 of which demonstrated beneficial effects; and 8 studies analyzed the effects on quality of life, with 6 reporting benefits. None of the articles analyzing nonmotor symptoms and quality of life showed negative effects.

CONCLUSIONS/IMPLICATIONS

Most of the studies analyzed demonstrated that MT has beneficial effects for the nonpharmacologic treatment of motor and nonmotor symptoms and quality of life of persons with PD. The use of music as a therapeutic tool combined with conventional therapies should be taken into account.

The reach-to-grasp movement in infants later diagnosed with autism spectrum disorder: a high-risk sibling cohort study

BACKGROUND

Although autism spectrum disorder (ASD) is characterized by impairments in social communication and the presence of repetitive behavior and/or restricted interests, there is evidence that motor impairments may be a contributing factor to the ASD phenotype. The purpose of this study was to examine the motor act of reaching-to-grasp in children at high risk (HR; with an older sibling diagnosed with ASD) and low-risk (LR; no family history of ASD) for ASD.

METHODS

Children were compared for differences in reaching-to-grasp based on sibling status and diagnostic outcome. Children were enrolled between 6 and 12 months of age and the reach-to-grasp movement was scored at 6, 9, (where available) 12, 15, 18, 24, and 36 months of age using the qualitative Skilled Reaching Rating Scale to determine the presence of any group-, age-, or sex-related differences in the mechanics of the reach-to-grasp movement using a Mixed Models analysis. At 36 months, all children underwent a gold-standard diagnostic assessment, which resulted in three outcome groups: HR children diagnosed with ASD (HR-ASD; n = 10), HR children not diagnosed with ASD (HR-N; n = 10), and low-risk children not diagnosed with ASD (LR; n = 10).

RESULTS

The group of children who were later diagnosed with ASD (HR-ASD group) showed higher (worse) total scores on the reach-to-grasp movement, as well as higher scores on the components of Orient, Lift, and Pronate compared to children in the LR and HR-N groups.

CONCLUSIONS

Our results support the growing literature indicating that children who are later diagnosed with ASD show impaired early motor performance. These results highlight the importance of early surveillance of children who are at elevated risk for ASD, and early initiatives should focus on early signs of the phenotype, including both movement and sensory differences (prodromal signs) prior to the emergence of diagnostic characteristics.

Deep Brain Stimulation for Parkinson's disease changes perception in the Rubber Hand Illusion

Parkinson’s disease (PD) alters cortico-basal ganglia-thalamic circuitry and susceptibility to an illusion of bodily awareness, the Rubber Hand Illusion (RHI). Bodily awareness is thought to result from multisensory integration in a predominantly cortical network; the role of subcortical connections is unknown. We studied the effect of modulating cortico-subcortical circuitry on multisensory integration for bodily awareness in 24 PD patients treated with subthalamic nucleus (STN) deep brain stimulation (DBS), in comparison to 21 healthy volunteers, using the RHI experiment. Typically, synchronous visuo-tactile cues induce a false perception of touch on the rubber hand as if it were the subject’s hand, whereas asynchronous visuo-tactile cues do not. However, we found that in the asynchronous condition, patients in the off-stimulation state did not reject the RHI as strongly as healthy controls; patients’ rejection of the RHI strengthened when STN-DBS was switched on, although it remained weaker than that of controls. Patients in the off-stimulation state also misjudged the position of their hand, indicating it to be closer to the rubber hand than controls. However, STN-DBS did not affect proprioceptive judgements or subsequent arm movements altered by the perceptual effects of the illusion. Our findings support the idea that the STN and subcortical connections have a key role in multisensory integration for bodily awareness. Decision-making in multisensory bodily illusions is discussed.

Actual and Illusory Perception in Parkinson's Disease and Dystonia: A Narrative Review

Sensory information is continuously processed so as to allow behavior to be adjusted according to environmental changes. Before sensory information reaches the cortex, a number of subcortical neural structures select the relevant information to send to be consciously processed. In recent decades, several studies have shown that the pathophysiological mechanisms underlying movement disorders such as Parkinson's disease (PD) and dystonia involve sensory processing abnormalities related to proprioceptive and tactile information. These abnormalities emerge from psychophysical testing, mainly temporal discrimination, as well as from experimental paradigms based on bodily illusions. Although the link between proprioception and movement may be unequivocal, how temporal tactile information abnormalities and bodily illusions relate to motor disturbances in PD and dystonia is still a matter of debate. This review considers the role of altered sensory processing in the pathophysiology of movement disorders, focusing on how sensory alteration patterns differ between PD and dystonia. We also discuss the evidence available and the potential for developing new therapeutic strategies based on the manipulation of multi-sensory information and bodily illusions in patients with these movement disorders.

Gait in Parkinson's disease: A visuo-cognitive challenge

Vision and cognition have both been related to gait impairment in Parkinson's disease (PD) through separate strands of research. The cumulative and interactive effect of both (which we term visuo-cognition) has not been previously investigated and little is known about the influence of cognition on vision with respect to gait. Understanding the role of vision, cognition and visuo-cognition in gait in PD is critical for data interpretation and to infer and test underlying mechanisms. The purpose of this comprehensive narrative review was to examine the interdependent and interactive role of cognition and vision in gait in PD and older adults. Evidence from a broad range of research disciplines was reviewed and summarised. A key finding was that attention appears to play a pivotal role in mediating gait, cognition and vision, and should be considered emphatically in future research in this field.

A protocol to examine vision and gait in Parkinson's disease: impact of cognition and response to visual cues

Background

Cognitive and visual impairments are common in Parkinson’s disease (PD) and contribute to gait deficit and falls. To date, cognition and vision in gait in PD have been assessed separately. Impact of both functions (which we term ‘visuo-cognition’) on gait however is likely interactive and can be tested using visual sampling (specifically saccadic eye movements) to provide an online behavioural measure of performance. Although experiments using static paradigms show saccadic impairment in PD, few studies have quantified visual sampling during dynamic motor tasks such as gait.

This article describes a protocol developed for testing visuo-cognition during gait in order to examine the: 1) independent roles of cognition and vision in gait in PD, 2) interaction between both functions, and 3) role of visuo-cognition in gait in PD.

Methods

Two groups of older adults (≥50 years old) were recruited; non-demented people with PD (n=60) and age-matched controls (n=40). Participants attended one session and a sub-group (n=25) attended two further sessions in order to establish mobile eye-tracker reliability. Participants walked in a gait laboratory under different attentional (single and dual task), environmental (walk straight, through a door and turning), and cueing (no visual cues and visual cues) conditions. Visual sampling was recorded using synchronised mobile eye-tracker and electrooculography systems, and gait was measured using 3D motion analysis.

Discussion

This exploratory study examined visuo-cognitive processes and their impact on gait in PD. Improved understanding of the influence of cognitive and visual functions on visual sampling during gait and gait in PD will assist in development of interventions to improve gait and reduce falls risk. This study will also help establish robust mobile eye-tracking methods in older adults and people with PD.

The measurement of visual sampling during real-world activity in Parkinson's disease and healthy controls: a structured literature review

BACKGROUND

Visual sampling techniques are used to investigate the complex role of vision during real-world activities in Parkinson's disease. Earlier research is limited to static simple tasks or measurement of eye movements alone, but more recent investigations involve more real-world activities. The approach to the objective measurement of eye movements varies with respect to instrumentation, testing protocols, and mediating factors that may influence visual sampling.

OBJECTIVES

The aim of this review was to examine previous work measuring visual sampling during real-world activities in Parkinson's disease to inform the development of robust protocols. Within this review a real-world activity was considered to be a goal-orientated motor task involving more than one body segment such as reaching or walking.

METHODS

Medline, Embase, PsychInfo, Scopus, Web of Knowledge, PubMed and the Cochrane library databases were searched. Two independent reviewers and an adjudicator screened articles that described quantitative visual sampling in people with Parkinson's disease and healthy controls.

RESULTS

Twenty full-text articles were screened and 15 met inclusion/exclusion criteria. A wide range of instruments and outcome measures were reported which were generally used in a task-dependent manner. Instrument reliability and validity was insufficiently reported in all studies. Few studies considered mediators of visual sampling such as visual or cognitive deficits.

CONCLUSIONS

Future research is required to accurately characterise visual impairments in Parkinson's disease and during real-world activities. Composite use of instruments may be required to achieve reliability and validity of visual sampling outcomes which need to be standardised. Recommendations also include assessment of cognition and basic visual function.

Listening to classical music ameliorates unilateral neglect after stroke

OBJECTIVE. We determined whether listening to excerpts of classical music ameliorates unilateral neglect (UN) in stroke patients. METHOD. In this within-subject study, we recruited and separately tested 16 UN patients with a right-hemisphere stroke under three conditions within 1 wk. In each condition, participants were asked to complete three subtests of the Behavioral Inattention Test while listening to classical music, white noise, or nothing. All conditions and the presentation of the tests were counterbalanced across participants. Visual analog scales were used to provide self-reported ratings of arousal and mood. RESULTS. Participants generally had the highest scores under the classical music condition and the lowest scores under the silence condition. In addition, most participants rated their arousal as highest after listening to classical music. CONCLUSION. Listening to classical music may improve visual attention in stroke patients with UN. Future research with larger study populations is necessary to validate these findings.

Prospective examination of visual attention during play in infants at high-risk for autism spectrum disorder: a longitudinal study from 6 to 36 months of age

Regulation of visual attention is essential to learning about one's environment. Children with autism spectrum disorder (ASD) exhibit impairments in regulating their visual attention, but little is known about how such impairments develop over time. This prospective longitudinal study is the first to describe the development of components of visual attention, including engaging, sustaining, and disengaging attention, in infants at high-risk of developing ASD (each with an older sibling with ASD). Non-sibling controls and high-risk infant siblings were filmed at 6, 9, 12, 15, 18, 24, and 36 months of age as they engaged in play with small, easily graspable toys. Duration of time spent looking at toy targets before moving the hand toward the target and the duration of time spent looking at the target after grasp were measured. At 36 months of age, an independent, gold standard diagnostic assessment for ASD was conducted for all participants. As predicted, infant siblings subsequently diagnosed with ASD were distinguished by prolonged latency to disengage ('sticky attention') by 12 months of age, and continued to show this characteristic at 15, 18, and 24 months of age. The results are discussed in relation to how the development of visual attention may impact later cognitive outcomes of children diagnosed with ASD.

Analysis of skilled forelimb movement in rats: the single pellet reaching test and staircase test

Brain damage, stroke, and neurodegenerative diseases such as Parkinson's or Huntington's disease can cause severe motor deficits in skilled forelimb use in both humans and rats. These deficits are typically analyzed in a reach-to-eat paradigm. Skilled reaching in rats has been found to be a good model of human skilled reaching. Therefore, rats serve as an excellent tool to monitor the development of deficits after neurological insults or changes after medical intervention. The following protocols comprise two different tests of rat skilled reaching. The single pellet reaching test is a paradigm that involves detailed rating and analysis of qualitative aspects of the reaching movement itself. The staircase test is an objective, high-throughput reaching task that allows reaching success (number of pellets eaten) to be investigated in multiple rats at the same time. Both tests have been used extensively to investigate motor deficits and effects of treatment.

Closing the gap between clinic and cage: sensori-motor and cognitive behavioural testing regimens in neurotoxin-induced animal models of Parkinson's disease

Animal models that make use of chemical toxins to adversely affect the nigrostriatal dopaminergic pathway of rodents and primates have contributed significantly towards the development of symptomatic therapies for Parkinson's disease (PD) patients. Although their use in developing neuro-therapeutic and -regenerative compounds remains to be ascertained, toxin-based mammalian and a range of non-mammalian models of PD are important tools in the identification and validation of candidate biomarkers for earlier diagnosis, as well as in the development of novel treatments that are currently working their way into the clinic. Toxin models of PD have and continue to be important models to use for understanding the consequences of nigrostriatal dopamine cell loss. Functional assessment of these models is also a critical component for eventual translational success. Sensitive behavioural testing regimens for assessing the extent of dysfunction exhibited in the toxin models, the degree of protection or improvement afforded by potential treatment modalities, and the correlation of these findings with what is observed clinically in PD patients, ultimately determines whether a potential treatment moves to clinical trials. Here, we review existing published work that describes the use of such behavioural outcome measures associated with toxin models of parkinsonism. In particular, we focus on tests assessing sensorimotor and cognitive function, both of which are significantly and progressively impaired in PD.

The use of rodent skilled reaching as a translational model for investigating brain damage and disease

Neurological diseases, including Parkinson's disease, Huntington's disease, and brain damage caused by stroke, cause severe motor impairments. Deficits in hand use are one of the most debilitating motor symptoms and include impairments in body posture, forelimb movements, and finger shaping for manipulating objects. Hand movements can be formally studied using reaching tasks, including the skilled reaching task, or reach-to-eat task. For skilled reaching, a subject reaches for a small food item, grasps it with the fingers, and places it in the mouth for eating. The human movement and its associated deficits can be modeled by experimental lesions to the same systems in rodents which in turn provide an avenue for investigating treatments of human impairments. Skilled reaching movements are scored using three methods: (1) end point measures of attempts and success, (2) biometric measures, and (3) movement element rating scales derived from formal descriptions of movement. The striking similarities between human and rodent reaching movements allow the analysis of the reach-to-eat movement to serve as a powerful tool to generalize preclinical research to clinical conditions.

The saccadic and neurological deficits in type 3 Gaucher disease

Our objective was to characterize the saccadic eye movements in patients with type 3 Gaucher disease (chronic neuronopathic) in relationship to neurological and neurophysiological abnormalities. For approximately 4 years, we prospectively followed a cohort of 15 patients with Gaucher type 3, ages 8-28 years, by measuring saccadic eye movements using the scleral search coil method. We found that patients with type 3 Gaucher disease had a significantly higher regression slope of duration vs amplitude and peak duration vs amplitude compared to healthy controls for both horizontal and vertical saccades. Saccadic latency was significantly increased for horizontal saccades only. Downward saccades were more affected than upward saccades. Saccade abnormalities increased over time in some patients reflecting the slowly progressive nature of the disease. Phase plane plots showed individually characteristic patterns of abnormal saccade trajectories. Oculo-manual dexterity scores on the Purdue Pegboard test were low in virtually all patients, even in those with normal cognitive function. Vertical saccade peak duration vs amplitude slope significantly correlated with IQ and with the performance on the Purdue Pegboard but not with the brainstem and somatosensory evoked potentials. We conclude that, in patients with Gaucher disease type 3, saccadic eye movements and oculo-manual dexterity are representative neurological functions for longitudinal studies and can probably be used as endpoints for therapeutic clinical trials.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00001289.