ABSTRACT
This study sought to determine the utility of an interlocking finger task in screening for parietal lobe dysfunction. The ability of 69 patients to imitate a standardised set of four interlocking finger figures was compared with concurrent performance on formal neurocognitive tests. Poor interlocking finger test scores correlated most highly with standard measures of parietal lobe dysfunction. In addition, an analytical model of parietal dysfunction indicated the interlocking finger test was similar to, if not better than, standard tests of parietal lobe dysfunction. Attempts to imitate these figures should serve as a fast and simple screen of parietal lobe dysfunction.
Subject(s)
Brain Diseases/diagnosis , Brain Diseases/physiopathology , Fingers/physiopathology , Gestures , Neuropsychological Tests , Parietal Lobe/physiopathology , Point-of-Care Systems , Adult , Aged , Aged, 80 and over , Feasibility Studies , Female , Humans , Male , Middle Aged , Reproducibility of ResultsABSTRACT
A 57 year old woman living independently in the community presented with four years of progressive spastic paraparesis and dementia. An extensive evaluation for the usual causes of these difficulties was unrevealing, but her serum phenylalanine concentration was markedly elevated and genetic analysis demonstrated mutations in the phenylalanine hydroxylase gene consistent with classic phenylketonuria. A protein restricted diet was associated with improvement in her condition. Although untreated phenylketonuria is typically associated with severe neurological dysfunction beginning in early childhood, this case shows that disability may be delayed until adulthood.
Subject(s)
Dementia/etiology , Paraparesis, Spastic/etiology , Phenylketonurias/complications , Phenylketonurias/diagnosis , Age of Onset , Cognition , Dementia/physiopathology , Diagnosis, Differential , Diet, Protein-Restricted , Disease Progression , Female , Gait , Genotype , Humans , Magnetic Resonance Imaging , Middle Aged , Mutation/genetics , Neuropsychological Tests , Paraparesis, Spastic/physiopathology , Phenotype , Phenylalanine/blood , Phenylketonurias/blood , Phenylketonurias/diet therapy , Phenylketonurias/genetics , Treatment OutcomeABSTRACT
Kosslyn (1987) proposed that the left hemisphere is better than the right hemisphere at categorical visuospatial processing while the right hemisphere is better than the left hemisphere at coordinate visuospatial processing. In 134 patients, one hemisphere (and then usually the other) was temporarily deactivated by intracarotid injection of sodium amobarbital. After a hemisphere was deactivated, a cognitive test battery was conducted, which included categorical and coordinate visuospatial tasks. Using this technique, the processing capabilities of the intact hemisphere could be determined, thus directly testing Kosslyn's hypothesis regarding hemispheric specialization. Specifically, if the left hemisphere does preferentially process categorical visuospatial relationships, then its deactivation should result in more errors during categorical tasks than right hemisphere deactivation and vise versa for the right hemisphere regarding coordinate tasks. The pattern of results obtained in both categorical and coordinate tasks was consistent with Kosslyn's hypothesis when task difficulty was sufficiently high. However, when task difficulty was low, a left hemispheric processing advantage was found for both types of tasks indicating that: (1) the left hemisphere may be better at "easy" tasks regardless of the type of task and (2) the proposed hemispheric processing asymmetry may only become apparent during sufficiently demanding task conditions. These results may explain why some investigators have failed to find a significant hemispheric processing asymmetry in visuospatial categorical and coordinate tasks.
