Parietal Lobes in Schizophrenia: Do They Matter?

Table 2

Recent structural magnetic resonance imaging (MRI) and computerized tomography (CT) studies on psychosis and schizophrenia with relevance to the parietal lobe.

Investigators	Subject groups	Average age of first scan (years)	Average years of followup	Image slice thickness	methods of analysis	Brain regions showing significant change in patients	Correlations between brain changes and clinical variables
Buchanan et al.; 2004 [22]	44 csz; 34 ctrls	39; 34	0	1.5 mm	ROI manual tracing	Smaller inferior prefrontal region vol. and reversal of the normal asymmetry of the inferior parietal cortex
Cannon et al.; 2002 [23]	20 MZ discordant pairs; 20 DZ discordant pairs; 20 MZ ctrls; 20 DZ ctrls	48; 49; 48; 47	0	1.2 mm	Three-dimensional cortical maps	Between patients and their MZ cotwins reduced grey matter in the superior parietal lobule, dorsolateral prefrontal cortex, Broca’s area, premotor cortex and frontal eye fields, superior temporal gyrus.	Disease-related deficits in grey matter were correlated with measures of symptom severity and cognitive dysfunction
Dazzan et al.; 2011 [24]	102 UHR	20	1	1.5 mm	VBM	Reductions in the frontal cortex in subjects who developed psychosis and the subgroup that subsequently developed SZ also showed smaller volumes in the parietal cortex
Dubb et al.; 2005 [25]	46 csz; 92 ctrls	29; 31	0	1.0 mm	VBM	Reduced vol. of the parietal and frontal lobe
Foong et al.; 2001[26]	25 csz; 30 ctrls	37; 35	0	5.0 mm	MTI	Frontal and temporal vol. reductions	Bilateral parieto-occipital cortex and genu of corpus callosum vol. reductions were associated with severity of negative symptoms in sz
Frederikse et al.; 2000 [27]	15 male scz; 15 female csz; 15 male ctrls; 15 female ctrls	39; 40; 39; 38	0	1.5 mm	ROI of the inferior parietal lobule	Male csz had a reversal of the normal left greater than right male asymmetry and smaller left inferior parietal lobule grey matter vol.; female csz did not differ from female ctrls
Hubl et al.; 2004 [28]	13 csz with to auditory hallucinations; 13 csz without auditory hallucinations; 13 ctrls	33; 31; 32	0	5.0 mm	DTI	pts with hallucinations had higher white matter directionality in the lateral parts of the temporoparietal section of the arcuate fasciculus and in parts of the anterior corpus callosum	Alterations of white matter fiber tracts in pts with frequent hallucinations lead to abnormal coactivation in regions related to the acoustical processing
Job et al.; 2005 [29]	65 GHR; 19 ctrls	21; 21	2	1.9 mm	VBM	GHR with right parietal grey matter, temporal grey matter, right frontal grey matter reductions	GHR with psychotic symptoms and converters showed a different spatial pattern of reductions
Jung et al.; 2009 [30]	29 UHR; 31 SZ; 29 ctrls	22; 24; 23	0	voxel size 0.45 × 0.45 × 0.9 mm	VBM	UHR: cortical thinning in prefrontal cortex, anterior cingulate cortex, inferior parietal cortex, parahippocampal cortex, and superior temporal gyrus	Cortical thinning was more pronounced in SZ compared with UHR and ctrls
Kubicki et al.; 2001 [31]	16 FE; 16 affective psychosis; 18 ctrls	26; 23; 24	0	1.5 mm	VBM	FE reduced volume of right inferior parietal lobule, right dorsolateral prefrontal cortex, left and right anterior cingulate gyrus, left and right insula
Kyriakopoulos; et al. 2009 [32]	17 adolescent-onset SZ; 17 adolescent ctrls; 17 adult-onset SZ; 17 adult ctrls	17; 16; 24; 24	0	2.5 mm	DTI	Individuals with adolescent onset SZ show fractional anisotropy decrease in parietal regionsindividuals with adult onset show additionally in frontal, temporal, and cerebellar regions	White matter abnormalities in SZ may depend on developmental stage at the time of illness onset
Minatogawa-Chang et al.; 2009 [33]	88 FEP; 86 ctrls	29; 31	0	voxel size 2 × 2 × 2 mm^3	MRI + controlled oral word association test + forward and backward digit span tests	Volume abnormalities in frontal and temporoparietal cortices	Cognitive deficits directly related to brain volume abnormalities in frontal and temporoparietal cortices in FEP subjects
Mitelman et al.; 2009 [34]	17 csz with good outcome; 17 csz with poor outcome; 13 ctrls	37; 47; 42	4	1.2 mm	DTI	At baseline, csz had smaller frontal, temporal, and parietal gray matter volumes than ctrls	Grey matter volumes in poor-outcome patients decline more rapidly than in patients with good outcome
Narr et al.; 2005 [35]	72 FE; 78 ctrls	25; 27	0	1.5 mm	MRI	Regional grey matter thinning in frontal, temporal and parietal heteromodal association cortices bilaterally
Nierenberg et al.; 2005 [36]	14 FE; 14 ctrls	18–55	0	1.5 mm	ROI	Smaller left angular gyrus vol.
Niznikiewicz et al.; 2000 [37]	15 male right-handed csz; 15 male right-handed ctrls	20–55	0	1.5 mm	ROI	Showed a reversed asymmetry in the inferior parietal lobule that was mainly seen in the angular gyrus
Rowland et al.; 2008 [38]	10 csz with neg. symptoms; 10 csz without neg. symptoms; 11 ctrls	46; 40; 37	0	2.2 mm	DTI	Reduced FA in the superior longitudinal fasciculus connecting parietal with frontal lobe	Support for altered frontal-parietal network in deficit SZ
Schultz et al.; 2009 [39]	54 FE; 54 ctrls	26; 27	0	1 mm	MRI	Cortical thinning in: dorsolateral and frontopolar cortices, anterior cingulate cortex, superior temporal cortices, and superior parietal lobe	Widespread reduction of cortical thickness, mostly in heteromodal cortices of frontotemporal networks
Sun 2003; [40]	23 UHR-N; 12 UHR-P	20; 20	1	1.5 mm	MRI	UHR-P : reduction in dorsolateral prefrontal cortex and orbitofrontal cortex	High-risk psychosis subjects showed orbitofrontal cortex reduction compared to FE
Sun et al.; 2005 [41]	23 FEP (16 FES); 11 csz; 28 ctrls	22; 33; 26	2	1.5 mm	MRI	FE versus ctrls: whole brain, left (trend), and right motor-premotor, left and right parietal, left and right dorsal prefrontal; csz versus FE: left and right dorsal prefrontal	FE brain surface retraction was similar to that of ctrls but significantly accelerated
Thompson et al.; 2001 [42]	12 SZ; 12 ctrls	14; 14	4.6	1.2 mm	MRI	Earliest scans: deficits in parietal brain regions; Latest scans: included dorsolateral prefrontal cortex and superior temporal gyri	Change patterns correlated with psychotic symptom severity
Whitford et al.; 2005 [43]	31 FE; 30 ctrls	19; 19	0	1.5 mm	VBM	left prefrontal cortex, left parietal and temporal cortex, right cerebellum, right parietal, frontal, and cortex reductions	Reality distortion syndrome score correlates with grey matter reduction in FE
Whitford et al.; 2006 [44]	41 FES followup: 25 FES; 47 ctrls followup: 26 ctrls	19; 19	2.6; 2.4	1.5 mm	VBM	Baseline: grey matter reductions in the frontal, parietal, and temporal cortices and cerebellum; Followup interval: especially in the parietal and temporal cortices further reductions
Narr et al.; 2001 [35]	48 csz; 48 ctrls	33; 32	0	0.9–1.4 mm	VBM	Left-dominant frontal, temporal, and insular grey matter reductions	Global assessment of functioning score correlated with grey matter vol. in the left inferior frontal and inferior parietal lobe
Zhou et al.; 2006 [45]	53 csz; 25 schizotypal disorder pts; 59 ctrls	25; 26; 24	0	1 mm	ROI	csz: reduction in parietal lobe; schizotypal subjects: postcentral gyrus volume reductions

csz: chronic schizophrenic patients; ctrls: healthy controls; ROI: region of interest; vol.: volume; MZ: monozygotic twins; DZ: dizygotic twins; VBM: Voxel-Based Morphometry; MTI: magnetization transfer imaging; SZ: schizophrenia; DTI: diffusion tensor imaging; FE: first episode schizophrenia; FEP: first episode psychosis; FA: fractional anisotropy; GHR: subjects at genetically high risk; UHR: ultra-high-risk patients; UHR-P: ultra-high-risk subjects who became psychotic; UHR-N: ultra-high-risk subjects who did not became psychotic, VBM: voxel-based morphometry.