Table 1.
Differences between visuospatial neglect symptoms and homonymous hemianopia
| Visuospatial neglect | Homonymous hemianopia | |
|---|---|---|
| Lesions | Fronto-parietal lesions (mainly territory of middle cerebral artery). | Postchiasmatic lesions of the visual tract or occipital lesions (mainly territory of posterior cerebral artery). |
| Awareness for deficits | Awareness for deficits is reduced (anosognosia), contralesional parts of the body, the external and internal world seem not to exist anymore. Anosodiaphoria can occur. | Awareness for deficits can be reduced initially but improves quickly. Anosognosia and anosodiaphoria are rare. |
| Modalities | Multimodal deficits can occur (visual, auditory, tactile, motor, olfactory). | Restricted to deficits of the visual modality. |
| Visual behaviour | Lack of attention to contralesional hemispace, independent of gaze direction. Deviation of gaze, head and sometime upper body towards the ipsilesional side. Reduced eye contact with conversational partner. | Loss of contralesional visual field with respect to the position of the head and eyes. Compensational eye and head movements towards the contralesional hemispace. |
| Drawing and cancellation | Contralesional omissions in drawing or cancellation tests. | Drawing and cancellation tests are mostly unaffected. |
| Line bisection | Ipsilesional deviation. | Contralesional deviation occurs frequently. |
| Attention (Posner paradigm) | Attentional shift is impaired. | Attentional shift is not impaired. |
| Compensation | Cueing on the contralesional side can lead to a transient improvement. | Compensation of visual deficits with head- and eye-movements occurs spontaneously (over-compensation may occur). Cueing does not have an impact. |
| Central fixation | Difficulty in maintaining central fixation. | Central fixation is not impaired. |
| VEPs | Near normal response of VEPs. Prolonged latency can occur on affected side. | Different response of VEPs in ipsi- and contralesional visual field. |
| Extinction | Visual extinction is commonly associated. | Visual extinction is not commonly associated. |