The Effects of Offline Anosognosia For Spatial Neglect on Neglect Rehabilitation

Anosognosia for hemispatial neglect is an intriguing phenomenon characterized by decreased awareness of spatial deficits, common in patients with right hemisphere stroke. However, it has not been examined as extensively as anosognosia for hemiplegia. In this study, we aim to investigate the relationship between the decrease in anosognosia for neglect and the improvement of spatial deficits.

Babinski described the term "anosognosia" in 1914 as a phenomenon characterized by unawareness of the paralysis in patients with right hemisphere lesions. Now, this term is used for not only ignorance of hemiplegia but also unawareness of somatosensory, visual deficits, or cognitive disorders like aphasia and memory problems. Another phenomenon, hemispatial neglect (HN), is inattention and decreased responsiveness to the contralesional half of the space that cannot be attributed to the primary motor and sensory deficits. In this perspective, anosognosia for spatial neglect is an intriguing issue. Chen et al. have proposed two different domains of anosognosia for HN. Offline (general) anosognosia means the unawareness of spatial deficits based on daily living experiences. Online (task-specific) anosognosia refers to underestimating spatial errors that are likely to occur in an upcoming task or have just occurred during the task. In this study, we will investigate the relationship between HN and offline anosognosia for HN in right hemisphere injured patients. Besides, we aim to examine how the increased awareness of spatial problems in daily life could affect the success of HN rehabilitation.

This retrospective cohort study will be conducted based on the medical records of HN patients with right hemisphere injury hospitalized in our rehabilitation clinic between 2012 and 2019. Demographic data such as age, gender, weeks after disease onset, rehabilitation duration; and clinical data such as HN severity, extinction phenomena, anosognosia level, sensorimotor functions of the affected (left) extremities, functional ambulation, and independence in activities of daily living will be extracted from medical records. The severities of HN and anosognosia for HN will be determined based on the scores of the Catherine Bergego Scale (CBS) assessments. The cohort will be divided into groups as anosognosia-positive and anosognosia-negative regarding the anosognosia scores of patients. Baseline parameters will be compared between the two groups. A patient-specific neglect rehabilitation program comprising 30-45-minute sessions five times a week will be considered, having been routinely administered to all patients to be included in this cohort. Based on this assumption, clinical data recorded at discharge will be included in the final analysis regarding the effect of rehabilitation on HN.

Eligibility Criteria:
Inclusion Criteria:

* Being older than 18 years of age
* Having subacute or chronic right hemisphere injury
* Having left-sided hemispatial neglect based on Catherine Bergego Scale assessment.

Exclusion Criteria:

* Acute cerebral injury (within the first two weeks of disease),
* Bilateral cerebral lesions
* Other neurological and psychiatric disorders that prevent evaluation of HN (e.g., severe cognitive or primer visual impairment)