Lesion Site and Neglect Anosognosia in Patients With Left Hemispatial Neglect

Babinski first defined anosognosia in 1914 as being unaware of paralysis in patients with right hemisphere stroke. Today, this term is used for the unawareness of various neurological and cognitive diseases or disabilities. One of these, anosognosia for hemispatial neglect, is an interesting phenomenon and has not been explored as thoroughly as hemiplegia anosognosia. Lesions of the right superior and inferior temporal gyrus, temporoparietal junction, and insula have been blamed for hemiplegia anosognosia. However, the neural correlates of neglect anosognosia are yet to be elucidated. Therefore, in this study, the investigators aim to investigate the relationship between lesion site and neglect anosognosia in subacute or chronic right hemispheric stroke patients with left hemispatial neglect.

In this retrospective study, the investigators will screen the medical records of our inpatient cognitive rehabilitation unit from 2011 to 2021. Patients diagnosed with left hemispatial neglect using Catherine Bergego Scale (CBS), line bisection, star cancellation, figure and shape copying, or representational drawing tests will be included in the study. Demographic and clinical data such as age, gender, weeks after stroke, stroke type (ischemic or hemorrhagic), lesion site, Brunnstrom stages, mini-mental status examination score and severities of neglect and neglect anosognosia will be noted.

Both neglect and neglect anosognosia severities will be determined using CBS. The underestimation of spatial deficits in daily living detected by parallel CBS testing will be considered as neglect anosognosia. The neglect anosognosia score will be calculated by subtracting the patient's self-assessment score from the evaluator-assigned CBS score. A difference of at least one point will be considered the presence of anosognosia. Patients will be divided into two groups with and without anosognosia according to the CBS-anosognosia score. Demographic and clinical features of patients with and without anosognosia will be compared. The correlation between neglect and neglect anosognosia scores will be examined.

The lesion site will be described by regions of interest (ROI) involvement using a semi-quantitative analyse. The association between anosognosia presence and involvement of the ROI will be analysed using the odds ratio with %95 confidence intervals. Neglect and anosognosia severities will also be compared between involvement and sparing of each ROI. Mini-mental state examination scores will be compared between the groups with and without anosognosia to address mental status, which may be a confounding factor in the evaluation of anosognosia.

Inclusion criteria

• Being older than 18 years of age
• Having a subacute or chronic right hemispheric supratentorial stroke
• Having left hemispatial neglect

Exclusion criteria

• Being in the first 2 weeks of the stroke
• Lesions involving the left hemisphere and/or brainstem and/or cerebellum
• Having other neurological conditions such as traumatic brain injury, central nervous system neoplasm, neurodegenerative or neuropsychiatric diseases
• Presence of severe cognitive impairment in the mini-mental state examination scale (<10 points)
• Lack of brain imaging data
• Having visual problems and psychiatric disorders hindering neglect and anosognosia evaluation