IS IT JUST BLACK AND WHITE?

Neglect syndrome is the unawareness of one side of the body when there is no sensory loss, which is why it is named as hemi spatial neglect. It is a deficit of awareness confined to a spatial location. It is still a question on how brain processes awareness of the self.

Neglect is caused by unilateral damage of the brain especially the right hemisphere and is mostly lesioned due to cerebral infarction or hemorrhage. Patients often don’t recognize objects, even people in their extra personal space (on their left side) contralesionally and reach out to objects on the ipsilesional side. Sometimes they fail to use the arm and leg of the affected side even if there is no paralysis. One would be unaware of their neglect and pretends to be totally fine with their perception, this is called as “anosognosia”.

Both the parietal lobes are involved in spatial representation of objects in space. However, right parietal lobe mediates attention to both the sides, so left hemisphere defect would not result in right spatial neglect. It is not just perceptual deficit because the patient is not actively ignoring the unattended side but it is due to inattention. Cortical Lesions in right parietal lobe and nearby temporo-parietal junction and sometimes inferior frontal lobe led to severe neglect.

Neglect can be of various types-sensory neglect, motor neglect, motivation aspect of neglect and inattention of neglect. Studies on how the brain processes oneself showed that the medial prefrontal cortex is affected but here in neglect mPFC are rarely affected. This provokes a question if, neglect is really a deficit in contralesional self-awareness or what more goes in it.