Differentiation of parkinsonian syndromes according to differences in executive functions.

Groups of patients with Parkinson's disease (PD), striatonigral degeneration-type multiple system atrophy (MSA) or progressive supranuclear palsy (PSP) with motor disability stages II and III according to Hoehn and Yahr, and a healthy control group were compared using neuropsychological tests of executive functions. The results indicate that all three patient groups were impaired in the tests of executive functions. In comparison with healthy subjects, the three patient groups showed impaired performance regarding verbal fluency, problem solving and verbal and figural working memory. Patients with PD differed significantly from healthy subjects in a test of verbal recency, while patients with MSA or PSP were unimpaired. The comparison of patient groups revealed no differences between PD and MSA patients. However, patients with PSP showed greater impairment in both phonemic and semantic fluency than patients with PD or MSA. Using discriminant function analysis, it was found that variables derived from four verbal fluency tasks (simple and alternate semantic and phonemic fluency) discriminated among the three patient groups at a level significantly exceeding chance. Over 90% of patients with PSP were correctly classified. Patients with PD and MSA were correctly classified in over 70% of cases. These results suggest that verbal fluency tasks may be sensitive measures in the differential diagnosis of PD, MSA and PSP.

Cognitive deficits before treatment among patients with brain tumors.

OBJECTIVE: There are few data available on the cognitive deficits of patients with primary or secondary intracranial mass lesions before treatment. The aim of the present study was to document the incidence of cognitive impairments among patients with brain tumors of the frontal or temporal lobes, immediately after diagnosis but before the commencement of treatment. METHODS: One hundred thirty-nine patients were neuropsychologically examined using standardized psychometric testing procedures that measured various aspects of memory, attention, language, and executive functions. Furthermore, reports by the patients of their own cognitive functioning in the weeks before treatment were recorded. RESULTS: With the classification of test performances below the 10th percentile as impaired, more than 90% of patients displayed impairments in at least one area of cognition. Impairments of executive functions were observed for 78% of patients, and impairments of memory and attention were observed for more than 60% of patients. Analysis of the correlation between the patients' own reports and the neuropsychological assessment results revealed only a weak relationship. No effects of anticonvulsant drugs on cognition were observed. CONCLUSION: The present findings suggest that most patients with brain tumors of the frontal or temporal lobes demonstrate impairments of cognitive functioning at the time of diagnosis. Therefore, for quality assessments of neurosurgical procedures, baseline evaluations of cognitive measures should be performed.

Vulnerability of the nigrostriatal system as detected by transcranial ultrasound.

OBJECTIVE: To assess the incidence of a hyperechogenic substantia nigra (SN) by transcranial sonography (TCS) in healthy people and to evaluate whether an enlarged hyperechogenic SN area is associated with functional impairment of the nigrostriatal system. BACKGROUND AND METHODS: Until now, preclinical impairment of the nigrostriatal system could be identified only by functional neuroimaging techniques such as PET in selected groups of patients. TCS is a new, noninvasive ultrasound technique that has demonstrated an increased echogenicity of the SN in patients with PD, whereas in most healthy individuals, the SN is either barely detectable or undetectable by TCS. RESULTS: Of 330 healthy volunteers, 8.6% exhibited an increased echogenicity of the SN. From these, 10 clinically healthy individuals with distinct unilateral or bilateral hyperechogenic signals in the SN region (SN area above 0.25 cm2) underwent comprehensive motor testing, neuropsychological assessment, MRI, and [18F]-dopa PET examination. With regard to motor functions, these individuals did not differ from 10 age- and sex-matched controls with a low echogenic SN and an area of echogenic signals below 0.2 cm2. Enlargement of hyperechogenic areas in the 10 healthy individuals was associated with a marked decrease in the accumulation of [15F]-dopa in the caudate nucleus and putamen. CONCLUSIONS: Substantia nigra hyperechogenicity appears to indicate a functional impairment of the nigrostriatal system. Transcranial sonography may be a suitable method of identifying persons at risk of nigrostriatal alterations, making possible the introduction of early neuroprotective therapy.