Disturbances of written language and associated abilities following damage to the right hemisphere

Abstract

The various anomalies which occur in the writing of people with right brain damage are described. They are compared with the reading and drawing impairments that these patients also show. In particular, the phenomenon of unilateral visual neglect is analyzed and hypotheses as to the nature of this disorder are put forward.

Letters lost in space: hemispace dependent handwriting errors

“…This suggests that after right brain damage, handwriting errors might not only be due to spatial deficits (such as spatial dysgraphia [11]), but also to language deficits (such as spatial agraphia). In light of this, we propose that language abilities, such as handwriting, might also depend upon where the hand is writing with respect to the body midline (egocentric frame of reference).…”

“…Whereas both language and space have been suggested to be mediated by widely distributed networks, involving the posterior temporo-parietal area, the dorso-lateral and medial prefrontal regions as well as the basal ganglia and the thalamus (for review see [22]), handwriting has been assumed to specifically involve the left superior parietal cortex [3][4][5]11]. However, in the present observation, we cannot accredit our patient's symptoms to this region or to a possible reorganisation of hemispheric language laterality from left to right because the patient was strongly right-handed for all skilled manual activities (Edinburgh Inventory).…”

“…However, other data show that handwriting also requires some attentional and spatial mechanisms, which rely on right hemispheric processing (for reviews see [2,10]). For example, frequent pathology of handwriting after right parietal damage is spatial dysgraphia [11]. This is a deficit of handwriting characterized by a tendency to write predominantly on the right side of a sheet of paper, to produce wandering lines with overlapping words and letters, and to split words incorrectly.…”

“…However, these dysgraphic errors are considered to be of purely spatial nature and have classically been opposed to agraphic errors (i.e. substitutions, transpositions, insertions of letters [11,12]), which are thought to be of language origin. In light of this, spatial dysgraphia has been suggested to highlight rather inter-hemispheric relationships than a pure contribution of the right hemisphere in handwriting [13].…”

“…Hemineglect is often exhibited after right brain damage and is characterized by a failure to attend to stimuli presented opposite to the side of brain damage [8]. Whereas hemineglect is usually investigated in both hemispaces separately [14,15], this has, to our knowledge, never been assessed in spatial dysgraphia [11]. We thus investigated this issue in a patient with spatial dysgraphia due to a right superior parietal lesion.…”