Neuropsychological and Glucose Metabolic Profiles in Asymmetric Parkinson’s Disease

Abstract

ABSTRACT:Patients with predominantly unilateral parkinsonian signs may provide a unique opportunity to evaluate the cerebral representation of cognitive functions characteristically affected in idiopathic Parkinson’s disease. Twenty hemiparkinsonian patients (ten left and ten right) and 10 healthy controls, matched for age and education, were studied with neuropsychological tests and positron emission tomography. Both right and left hemiparkinsonians evidenced impairments in visuospatial and verbal episodic memory function, but had no deficits in executive abilities, compared to controls. None of the neuropsychological test scores distinguished right from left hemiparkinsonians. Glucose metabolic profiles were identical for the three groups in all cortical areas assessed; in the subcortex however, lenticular hypermetabolism contralateral to the predominant side of motor involvement was evident in the left hemiparkinsonian group. Correlational analysis revealed that higher glucose metabolic rates in the basal ganglia of these hemiparkinsonians were associated with lower visuospatial test scores. In frontal and parietal cortex, decreasing glucose metabolism was positively associated with neurobehavioral function; in temporal cortex, measures of attention and memory decreased with increasing glucose metabolic rates.

Cognitive Differences Between Patients with Left-sided and Right-sided Parkinson’s Disease. A Review

“…These latter studies further diverge in the way the degree of asymmetry was defined. Eight studies based their classification on subjective history and examination (Barber et al 1985;Blonder et al 1989;Bowen 1976;Direnfeld et al 1984;Huber et al 1989;Mohr et al 1992;Schendan et al 2009;Villardita et al 1983), while others used a standardised scale, such as the Columbia Rating Scale or the Unified Parkinson's Disease Rating Scale (UPDRS). Among these, there are further differences in the cutoff-values that were applied.…”

“…The second study showed that patients with left-sided symptom onset were more impaired on object recognition compared to patients with right-sided onset (Tomer et al 1993). The remaining eight studies did not reveal any differences between LPD and RPD patients (Agniel et al 1991;Bentin et al 1981;Clair et al 1998;Direnfeld et al 1984;Levin et al 1991;Mohr et al 1992;Spicer et al 1988;Viitanen et al 1994). Summary.…”

“…Four studies discovered a worse performance in the LPD group for mental rotation and imagery (Lee et al 1998), visual maps and Weinstein Body Scheme (Bowen et al 1972), Judgement of size (Harris et al 2003), and Judgement of Line Orientation (Tomer et al 1993). Only one study revealed a disadvantage for the RPD group who performed worse on left-right orientation (Mohr et al 1992). One study showed a difference in performance between LPD and RPD in the mental rotation of hands, and showed that the deficit was dependent upon visual field presentation (Amick et al 2006b).…”

“…Twelve of them used the Block Design subtest (Agniel et al 1991;Barber et al 1985;Bentin et al 1981;Blonder et al 1989;Direnfeld et al 1984;Hietanen and Teräväinen 1989;Huber et al 1989Huber et al , 1992Levin et al 1991;Mohr et al 1992;Starkstein et al 1987;Viitanen et al 1994), but only one study unveiled a difference between LPD and RPD on this test, finding an advantage for the RPD group (Huber et al 1992). Similar findings were reported for the Object Assembly and Picture Completion subtests: most studies did not reveal a difference between LPD and RPD (Barber et al 1985;Clair et al 1998;Mohr et al 1992;Starkstein et al 1987). Only one study found a disadvantage for RPD patients on both subtests (Huber et al 1992) and one reported a poor performance of RPD patients on Picture Completion (Hietanen and Teräväinen 1989).…”

Impaired performance on the Wisconsin Card Sorting Test under left- when compared to right-sided deep brain stimulation of the subthalamic nucleus in patients with Parkinson’s disease

“…Studies that have attempted to explore the relationship between cognitive impairments and the asymmetry of motor symptoms in PD have found contradictory results. While some studies reported no correlation between the laterality of motor symptoms and cognitive asymmetry scores [1,20], Tomer et al [33] found that initial symptoms on the left side of the body were associated with more pronounced cognitive decline. However, comparison of test results between patients with left-or right-sided onset of initial symptoms yielded comparable mean values under both stimulation conditions.…”