Planum Parietale Volume in Antipsychotic-Naïve Schizophrenia

Abstract

To the Editor: “The parietal lobe receives little attention in current neuropathological models of schizophrenia, and there has been little systematic investigation of this area,”1 despite its recognized importance in processes that are likely disturbed in schizophrenia, such as language,2 spatial working memory, and attention. The inferior parietal lobule (IPL), a part of the parietal lobe, also forms the part of the heteromodal association cortex that has been proposed as the site of the key abnormality in schizophrenia.3 It is subdivided into the supramarginal gyrus (area 39) and angular gyrus (area 40). These two structures are a part of the semantic-lexical network that supports “word meanings,” represented by a “grid of connectivity” that constitutes a “final pathway for the chunking of words into thought.”2 Further, PET and fMRI studies have confirmed the role of the IPL, particularly the angular gyrus, in language comprehension.4 First-rank symptoms (FRS), a group of intriguing experiences characterized by a striking breach of “self versus non-self” boundaries, have had a critical influence on the diagnosis of schizophrenia.5 The IPL is also implicated in the pathogenesis of FRS in schizophrenia.3