scholarly journals Sensorimotor cortex forms prism adaptation memories in older adults and stroke patients

2020 ◽  
Author(s):  
Gershon Spitz ◽  
Pierre Petitet ◽  
Janet Bultitude ◽  
Alessandro Farnè ◽  
Jacques Luaute ◽  
...  
Keyword(s):  
Sensorimotor Cortex ◽  
Right Hemisphere ◽  
State Space Model ◽  
Prism Adaptation ◽  
Spatial Neglect ◽  
Behavioural Intervention ◽  
Stroke Survivors ◽  
Stroke Patients ◽  
After Effect ◽  
The Brain

AbstractStroke is the largest cause of complex disability in adults. Approximately half of right-hemisphere stroke survivors suffer spatial neglect–an inability to voluntarily orient to people or objects in contralesional space. Neglect is a significant impediment to successful community reintegration. Prism adaptation (PA) is a promising behavioural intervention that can alleviate symptoms of spatial neglect. PA induces a leftward pointing bias–the prism after-effect (AE). In neglect, the prism AE generalises to improve other sensory, motor, and cognitive domains. Although the formation of an AE is a key index in neglect, we do not yet know where it is formed in the brain. Here, we used a novel computational fMRI-based approach to study, for the first time, the brain circuits that mediate the formation of PA in stroke survivors and age matched controls. Healthy individuals (n = 17) and stroke patients (n = 11) performed prism adaptation during fMRI. Temporal signatures of memory formation were extracted from the behavioural data using a state-space model and regressed against the fMRI data. This revealed that, in both groups, fMRI signal in left sensorimotor cortex correlated with the gradual formation of the prism after-effect during adaptation. This indicates that the sensorimotor cortex may be a useful target for neuromodulation that aims to improve the persistence of therapeutic prism after effects.

scholarly journals Prism adaptation speeds reach initiation in the direction of the prism after-effect.

2021 ◽  
Author(s):  
Christopher Lee Striemer ◽  
Carley Borza
Keyword(s):  
Sensory Input ◽  
Right Hemisphere ◽  
Prism Adaptation ◽  
Spatial Neglect ◽  
Egocentric Reference Frame ◽  
After Effect ◽  
The Right ◽  
Reach Planning ◽  
Direction Opposite ◽  
Healthy Participants

Damage to the temporal-parietal cortex in the right hemisphere often leads to spatial neglect – a disorder in which patients are unable to attend to sensory input from their contralesional (left) side. Neglect has been associated with both attentional and premotor deficits. That is, in addition to having difficulty with attending to the left side, patients are often slower to initiate leftward vs. rightward movements (i.e., directional hypokinesia). Previous research has indicated that a brief period of adaptation to rightward shifting prisms can reduce symptoms of neglect by adjusting the patient’s movements leftward, towards the neglected field. Although prism adaptation has been shown to reduce spatial attention deficits in patients with neglect, very little work has examined the effects of prisms on premotor symptoms. In the current study, we examined this in healthy individuals using leftward shifting prisms to induce a rightward shift in the egocentric reference frame, similar to neglect patients prior to prism adaptation. Specifically, we examined the speed with which healthy participants initiated leftward and rightward reaches (without visual feedback) prior to and following adaptation to either 17° leftward (n=16) or 17° rightward (n=15) shifting prisms. Our results indicated that, following adaptation, participants were significantly faster to initiate reaches towards targets located in the direction opposite the prism shift. That is, participants were faster to initiate reaches to right targets following leftward prism adaptation, and were faster to initiate reaches to left targets following rightward prism adaptation. Overall these results are consistent with the idea that prism adaptation can influence the speed with which a reach can be planned toward a target in the direction opposite the prism shift, possibly through altering activity in neural circuits involved in reach planning.

Prism Adaptation Therapy Enhances Rehabilitation of Stroke Patients With Unilateral Spatial Neglect

2011 ◽  
Vol 25 (8) ◽  
pp. 711-720 ◽  
Author(s):  
Katsuhiro Mizuno ◽  
Tetsuya Tsuji ◽  
Toru Takebayashi ◽  
Toshiyuki Fujiwara ◽  
Kimitaka Hase ◽  
...  
Keyword(s):  
Prism Adaptation ◽  
Spatial Neglect ◽  
Stroke Patients ◽  
Unilateral Spatial Neglect

scholarly journals In Search for the Meaning of Illness: Content of Narrative Discourse Is Related to Cognitive Deficits in Stroke Patients

2021 ◽  
Vol 11 ◽  
Author(s):  
Anna R. Egbert ◽  
Agnieszka Pluta ◽  
Joanna Powęska ◽  
Emilia Łojek
Keyword(s):  
Cognitive Impairment ◽  
Subjective Experience ◽  
Right Hemisphere ◽  
Narrative Discourse ◽  
Stroke Survivors ◽  
Stroke Patients ◽  
Illness Onset ◽  
Bonferroni Adjustment ◽  
Experience Of Illness ◽  
Cognitive Problems

Stroke survivors undergo a thorough cognitive diagnosis that often involves administration of multiple standardized tests. However, patient’s narrative discourse can provide clinicians with additional knowledge on patient’s subjective experience of illness, attitude toward current situation, and motivation for treatment. We evaluated the methods of analyzing thematic content and story types in relationship to cognitive impairment in stroke survivors with no aphasia (including 9 left hemisphere damage – LHD patients, and 16 right hemisphere damage – RHD patients). Cognitive impairment was evaluated in comparison to a group of 25 patients with orthopaedic injury not involving the brain. Our findings primarily show that higher elaboration on own cognitive problems, physical ailments or coping strategies in LHD patients and cognitive problems, emotional issues and circumstances of illness onset in RHD patients is related to deficits in executive functions and retrieval of information from memory. Furthermore, RHD patients who use more chaos story type show lower executive functioning. However, these results did not survive the significance threshold of p < 0.05 after Bonferroni adjustment for multiple comparisons. In conclusion, this study provides preliminary evidence that stroke survivor’s narrative can constitute an additional source of clinically-relevant information regarding patient’s experience of illness and attitude toward recovery. This knowledge can aid clinicians and nurses in everyday interactions with the patients and support individualized strategy to treatment. Still, the current results need be confirmed with future studies in a larger cohort of stroke patients.

scholarly journals Immersive virtual prism adaptation therapy with depth sensing camera: A feasibility study with functional near infrared spectroscopy in healthy adults

2021 ◽  
Author(s):  
Sungmin Cho ◽  
Won-Seok Kim ◽  
Jihong Park ◽  
Seung Hyun Lee ◽  
Jongseung Lee ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Right Hemisphere ◽  
Prism Adaptation ◽  
Spatial Neglect ◽  
Depth Sensing ◽  
Functional Near Infrared Spectroscopy ◽  
Unilateral Spatial Neglect ◽  
The Right

Unilateral spatial neglect (USN) is common after stroke and associated with poor functional recovery. Prism adaptation (PA) is one of the most supported modality able to ameliorate USN but underapplied due to several issues. Using immersive virtual reality and depth-sensing camera, we developed the virtual prism adaptation therapy (VPAT) to overcome the limitations in conventional PA. In this study, we investigated whether VPAT can induce behavioral adaptations and which cortical area is most significantly activated. Fourteen healthy subjects participated in this study. The experiment consisted of four sequential phases (pre-VAPT, VPAT-10°, VPAT-20°, and post-VPAT) with functional near-infrared spectroscopy recordings. Each phase consisted of alternating target pointing and resting (or clicking) blocks. To find out the most significantly activated area during pointing in different phases (VPAT-10°, VPAT-20°, and Post-VPAT) in contrast to pointing during the pre-VPAT phase, we analyzed changes in oxyhemoglobin concentration during pointing. The pointing errors of the virtual hand deviated to the right-side during early pointing blocks in the VPAT-10°and VPAT-20°phases. There was a left-side deviation of the real hand to the target in the post-VPAT phase. The most significantly activated channels were all located in the right hemisphere, and possible corresponding cortical areas included the dorsolateral prefrontal cortex and frontal eye field. In conclusion, VPAT may induce behavioral adaptation with modulation of the dorsal attentional network. Future clinical trials using multiple sessions of a high degree of rightward deviation VPAT over a more extended period are required in stroke patients with unilateral spatial neglect.

Search pattern in a verbally reported visual scanning test in patients showing spatial neglect

2002 ◽  
Vol 8 (3) ◽  
pp. 382-394 ◽  
Author(s):  
HANS SAMUELSSON ◽  
E.K. ELISABETH HJELMQUIST ◽  
CHRISTER JENSEN ◽  
CHRISTIAN BLOMSTRAND
Keyword(s):  
Right Hemisphere ◽  
Repeated Reading ◽  
Spatial Neglect ◽  
Search Pattern ◽  
Common Finding ◽  
Repeated Readings ◽  
Stroke Patients ◽  
Visuospatial Neglect ◽  
Normal Controls

The present study of right hemisphere stroke patients showed that presence of visuospatial neglect in conventional neglect tests at the postacute stage was strongly associated with an aberrant search pattern in a verbally reported visuo-perceptual scanning test. Compared with normal controls, patients with visuospatial neglect showed a greater proportion of repeated readings of the same target, shorter search sequences, more shifts between horizontal, vertical, and diagonal search, and lower proportion of horizontal search. The relation between spatial neglect and a deficient search pattern was strongly influenced by the asymmetric allocation of attention in the scanning test, with the exception for the proportion of repeated reading which was not influenced by this asymmetry. At follow-up, a significant recovery was noted in the neglect group for the proportion of repeated readings and for the asymmetry in the allocation of attention. However, a high number of omitted targets in the search test was still a common finding in the neglect group and it was suggested that a non-lateralized attentional deficit may have played an important role behind the ineffective search at this point of time. (JINS, 2002, 8, 382–394.)

scholarly journals Left egocentric neglect in early subacute right-stroke patients is related to damage of the superior longitudinal fasciculus

2021 ◽  
Author(s):  
Barbara Spanò ◽  
Davide Nardo ◽  
Giovanni Giulietti ◽  
Alessandro Matano ◽  
Ilenia Salsano ◽  
...  
Keyword(s):  
White Matter ◽  
Right Hemisphere ◽  
Neural Substrates ◽  
Spatial Neglect ◽  
Stroke Patients ◽  
Superior Longitudinal Fasciculus ◽  
Unilateral Spatial Neglect ◽  
Object Based ◽  
The Right ◽  
The Relationship

AbstractA typical consequence of stroke in the right hemisphere is unilateral spatial neglect. Distinct forms of neglect have been described, such as space-based (egocentric) and object-based (allocentric) neglect. However, the relationship between these two forms of neglect is still far from being understood, as well as their neural substrates. Here, we further explore this issue by using voxel lesion symptoms mapping (VLSM) analyses on a large sample of early subacute right-stroke patients assessed with the Apples Cancellation Test. This is a sensitive test that simultaneously measures both egocentric and allocentric neglect. Behaviourally, we found no correlation between egocentric and allocentric performance, indicating independent mechanisms supporting the two forms of neglect. This was confirmed by the VLSM analysis that pointed out a link between a damage in the superior longitudinal fasciculus and left egocentric neglect. By contrast, no association was found between brain damage and left allocentric neglect. These results indicate a higher probability to observe egocentric neglect as a consequence of white matter damages in the superior longitudinal fasciculus, while allocentric neglect appears more “globally” related to the whole lesion map. Overall, these findings on early subacute right-stroke patients highlight the role played by white matter integrity in sustaining attention-related operations within an egocentric frame of reference.

scholarly journals Spatial neglect in the digital age – Influence of presentation format on patients' test behavior

2021 ◽  
Author(s):  
Hannah Rosenzopf ◽  
Christoph Sperber ◽  
Franz Wortha ◽  
Daniel Wiesen ◽  
Annika Muth ◽  
...  
Keyword(s):  
Machine Learning ◽  
Test Scores ◽  
Right Hemisphere ◽  
Search Behavior ◽  
Spatial Neglect ◽  
Presentation Format ◽  
Stroke Patients ◽  
Test Behavior ◽  
Paper And Pencil ◽  
Behavioral Markers

Computerization of diagnostic neglect tests can deepen our knowledge of neglect specific abnormalities, by effortlessly providing additional behavioral markers that are hardly extractable from existing paper-and-pencil versions. However, so far it is not known whether the digitization and/or a change in size format impact neglect patients' search behavior and test scores and thus require adjustments of cut-off criteria. We compared the Center of cancellation (CoC) measure of right hemisphere stroke patients with spatial neglect in two cancellation tasks across different modalities (paper-and-pencil vs. digital) and display sizes (small, medium, large). We found that the CoC measure did neither vary considerably between paper-and-pencil versus digital versions, nor between different digital size formats. The CoC derived from cancellation tasks thus seems robust to test digitization. A further aim of the present study was to evaluate three additional parameters of search behavior which became available through digitization. We observed slower search behavior, increased distance between two consecutively identified items, and signs of a more strategic search for neglect patients than control patients without neglect. Machine learning classifications indicated that - beyond the CoC measure - the latter three variables can help to differentiate stroke patients with spatial neglect from those without.

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