Differentiation of parkinsonian syndromes according to differences in executive functions

Smaller and Denser Speech Graphs in Nondemented Patients with Progressive Supranuclear Palsy

The well-established semantic fluency test measures the ability to produce a sequence of spoken words from a particular category within a limited period of time. Like patients with Parkinson's disease (PD), patients with progressive supranuclear palsy (PSP) tend to produce fewer correct words than age-matched healthy adults. This study further examined the difference between patients with PSP and PD in their semantic fluency performance using a graph theory-based approach. Twenty-nine patients with PSP Richardson's syndrome (PSP-RS), thirty-eight patients with PD, and fifty-one healthy controls (HC) were recruited. All participants completed a standard semantic fluency test (animals). Their verbal responses were recorded, transcripted, and transformed into directed speech graphs. The speech graphs of the PSP-RS group showed higher density, shorter diameter, and shorter average shortest path than those of the PD and HC groups. It indicates that the PSP-RS group produced smaller and denser speech graphs than the PD and HC groups. In the PSP-RS group, moreover, the average shortest paths of the speech graphs correlated with the severity of motor symptoms. This study shows the potential of the graph theory-based approach in distinguishing the semantic fluency performance of nondemented patients with PSP-RS and PD.

Cognition and freezing of gait in Parkinson's disease: A systematic review and meta-analysis

Freezing of gait (FOG) is a common and disabling symptom in people with Parkinson's Disease (PwPD). Although cognition is thought to be worse in PwPD who freeze, a comprehensive analysis of this relationship will inform future research and clinical care. This systematic review and meta-analysis compared cognition between PwPD who do and do not exhibit FOG across a range of cognitive domains and assessed the impact of disease severity and medication status on this relationship. 145 papers (n = 9010 participants) were included in the analysis, with 144 and 138 articles meeting the criteria to assess moderating effects of disease severity and medication status, respectively. PwPD who freeze exhibited worse cognition than PwPD without FOG across global cognition, executive function/attention, language, memory, and visuospatial domains. Greater disease severity and "ON" levodopa medication status moderated the FOG status-cognition relationship in global cognitive performance but not in other cognitive domains. This meta-analysis confirmed that cognition is worse in PwPD with FOG and highlights the importance of disease severity and medication status in this relationship.

The Cognitive Profile of Atypical Parkinsonism: A Meta-Analysis

Atypical Parkinsonism (AP) syndromes are characterized by a wide spectrum of non-motor symptoms including prominent attentional and executive deficits. However, the cognitive profile of AP and its differences and similarities with that of Parkinson's Disease (PD) are still a matter of debate. The present meta-analysis aimed at identifying patterns of cognitive impairment in AP by comparing global cognitive functioning, memory, executive functions, visuospatial abilities, language, non-verbal reasoning, and processing speed test performances of patients with AP relative to healthy controls and patients with PD. All investigated cognitive domains showed a substantial impairment in patients with AP compared to healthy controls. When AP syndromes were considered separately, their cognitive functioning was distributed along a continuum from Multiple Systemic Atrophy at one extreme, with the least impaired cognitive profile (similar to that observed in PD) to Progressive Supranuclear Palsy, with the greatest decline in global cognitive and executive functioning (similar to Corticobasal Syndrome). These findings indicate that widespread cognitive impairment could represent an important clinical indicator to distinguish AP from other movement disorders.

Cognitive and Autonomic Dysfunction in Multiple System Atrophy Type P and C: A Comparative Study

Multiple System Atrophy (MSA) is a rare neurodegenerative disease, clinically defined by a combination of autonomic dysfunction and motor involvement, that may be predominantly extrapyramidal (MSA-P) or cerebellar (MSA-C). Although dementia is generally considered a red flag against the clinical diagnosis of MSA, in the last decade the evidence of cognitive impairment in MSA patients has been growing. Cognitive dysfunction appears to involve mainly, but not exclusively, executive functions, and may have different characteristics and progression in the two subtypes of the disease (i.e., MSA-P and MSA-C). Despite continued efforts, combining in-vivo imaging studies as well as pathological studies, the physiopathological bases of cognitive involvement in MSA are still unclear. In this view, the possible link between cardiovascular autonomic impairment and decreased cognitive performance, extensively investigated in PD, needs to be clarified as well. In the present study, we evaluated a cohort of 20 MSA patients (9 MSA-P, 11 MSA-C) by means of a neuropsychological battery, hemodynamic assessment (heart rate and arterial blood pressure) during rest and active standing and bedside autonomic function tests assessed by heart rate variability (HRV) parameters and sympathetic skin response (SSR) in the same experimental session. Overall, global cognitive functioning, as indicated by the MoCA score, was preserved in most patients. However, short- and long-term memory and attentional and frontal-executive functions were moderately impaired. When comparing MSA-P and MSA-C, the latter obtained lower scores in tests of executive functions and verbal memory. Conversely, no statistically significant difference in cardiovascular autonomic parameters was identified between MSA-P and MSA-C patients. In conclusion, moderate cognitive deficits, involving executive functions and memory, are present in MSA, particularly in MSA-C patients. In addition, our findings do not support the role of dysautonomia as a major driver of cognitive differences between MSA-P and MSA-C.

Do patients with Progressive Supranuclear Palsy have episodic memory impairment? A systematic review

Background

Progressive supranuclear palsy (PSP) is the most common atypical parkinsonism and has executive dysfunction as a core feature. The magnitude of episodic memory disturbance in PSP is yet to be clarified.

Objectives

To investigate how impaired is episodic memory in PSP compared to healthy controls and other neuropsychiatric disorders. Also, we sought to identify the brain correlates underlying these memory disturbances.

Methods

We performed a systematic search on PubMed and Scopus, combining the terms "progressive supranuclear palsy" AND "memory". The search was limited to papers published in English, French, Portuguese or Spanish, with no chronological filters. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed.

Results

The initial search returned 464 results. After extraction of duplicates, 356 records were screened, leading to inclusion of 38 studies. Most studies found that PSP patients had lower scores on episodic memory compared to healthy controls. In addition, the majority of studies suggest that PSP does not differ from Parkinson's disease and from atypical parkinsonism in terms of episodic memory performance. The same is seen for PSP and frontotemporal dementia. Conversely, episodic memory impairment seems to be greater in typical Alzheimer's disease compared to PSP. Neuroimaging findings indicate that striatofrontal structures may be involved in PSP episodic memory dysfunction, while no associations with mesial structures (including hippocampi) were found.

Conclusions

Episodic memory is impaired in PSP. Whether this amnesia refers to executive dysfunction is still controversial. More studies are warranted to clarify the neural basis of memory impairment in PSP.

Frontal Atrophy and Executive Dysfunction Relate to Complex Numbers Impairment in Progressive Supranuclear Palsy

BACKGROUND

Previous research finds a range of numbers impairments in Parkinsonian syndromes (PS), but has largely focused on how visuospatial impairments impact deficits in basic numerical processes (e.g., magnitude judgments, chunking). Differentiation between these basic functions and more complex numerical processes often utilized in everyday tasks may help elucidate neurocognitive and neuroanatomic bases of numbers deficits in PS.

OBJECTIVE

To test neurocognitive and neuroanatomic correlates of complex numerical processing in PS, we assessed number abilities, neuropsychological performance, and cortical thickness in progressive supranuclear palsy (PSP) and Lewy body spectrum disorders (LBSD).

METHODS

Fifty-six patients (LBSD = 35; PSP = 21) completed a Numbers Battery, including basic and complex numerical tasks. The Mini-Mental State Exam (MMSE), letter fluency (LF), and Judgment of Line Orientation (JOLO) assessed global, executive, and visuospatial functioning respectively. Mann-Whitney U tests compared neuropsychological testing and rank-transformed analysis of covariance (ANCOVA) compared numbers performance between groups while adjusting for demographic variables. Spearman's and partial correlations related numbers performance to neuropsychological tasks. Neuroimaging assessed cortical thickness in disease groups and demographically-matched healthy controls.

RESULTS

PSP had worse complex numbers performance than LBSD (F = 6.06, p = 0.02) but similar basic numbers performance (F = 0.38, p > 0.1), covarying for MMSE and sex. Across syndromes, impaired complex numbers performance was linked to poor LF (rho = 0.34, p = 0.01) but not JOLO (rho = 0.23, p > 0.05). Imaging revealed significant frontal atrophy in PSP compared to controls, which was associated with worse LF and complex numbers performance.

CONCLUSION

PSP demonstrated selective impairments in complex numbers processing compared to LBSD. This complex numerical deficit may relate to executive dysfunction and frontal atrophy.

Phonemic Verbal Fluency and Midbrain Atrophy in Progressive Supranuclear Palsy

BACKGROUND

The neuropsychological profile of progressive supranuclear palsy (PSP) patients is mainly characterized by executive dysfunction, but the relationship between the latter and midbrain atrophy is still unclear.

OBJECTIVE

The aims of the study were to investigate which test evaluating executive functioning is more frequently impaired in PSP patients and to evaluate the relationship between midbrain-based MRI morphometric measures and executive dysfunction.

METHODS

PSP patients who had undergone a neuropsychological battery assessing executive functioning with the Frontal Assessment Battery (FAB), the phonemic verbal fluency F-A-S, the Raven's Progressive Colored Matrix, and the Stroop word colors test (time and errors) were enrolled in the study. A group of Parkinson's disease (PD) patients matched by age, sex, education, and global cognitive status was selected. All the enrolled patients also underwent a volumetric T1-3D brain MRI.

RESULTS

Thirty-five PSP patients and 35 PD patients were enrolled. Patients with PSP as compared to patients with PD showed a significant greater impairment in verbal fluency (16.0±7.9 and 23.4±8.7 words/180 s; p < 0.001) and a significant lower score at the FAB total score (11.5±3.8 and 13.7±3.4; p = 0.013). Midbrain area was significantly smaller in PSP patients than in PD patients (83.9±20.1 and 134.5±19.9 mm2; p < 0.001). In PSP patients, a significant positive correlation between verbal fluency and the midbrain area (r = 0.421; p = 0.028) was observed.

CONCLUSION

Our findings suggest that the phonemic verbal fluency is among the most frequently impaired executive functions in PSP patients and is strongly correlated to midbrain atrophy.

Language impairment in progressive supranuclear palsy and corticobasal syndrome

Although commonly known as movement disorders, progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) may present with changes in speech and language alongside or even before motor symptoms. The differential diagnosis of these two disorders can be challenging, especially in the early stages. Here we review their impact on speech and language. We discuss the neurobiological and clinical-phenomenological overlap of PSP and CBS with each other, and with other disorders including non-fluent agrammatic primary progressive aphasia and primary progressive apraxia of speech. Because language impairment is often an early and persistent problem in CBS and PSP, there is a need for improved methods for language screening in primary and secondary care, and more detailed language assessments in tertiary healthcare settings. Improved language assessment may aid differential diagnosis as well as inform clinical management decisions.

[Guidelines for the Neuropsychological Assessment of Patients with Parkinson's Disease]

BACKGROUND

Presence of mild cognitive impairment is currently the best predictor for the development of Parkinson's disease dementia. Diagnostic criteria for both Parkinson's with mild cognitive impairment and Parkinson's disease dementia have been suggested by the Movement Disorder Society. However, not all cognitive tests recommended are available in the German language with proper standard values.

OBJECTIVES

To define evidence-based guidelines for neuropsychological assessment of patients with Parkinson's disease in German.

METHODS

Two systematic literature searches were conducted. First, articles that presented international guidelines (consensus papers or reviews) for the application of standardized neuropsychological assessments for the diagnosis of cognitive impairment in Parkinson's disease were selected. Of those, only neuropsychological assessments in German language with normative values referring either to a German, Austrian, or Swiss population were considered. Second, articles comparing test performances of healthy controls vs. Parkinson's disease and/or different cognitive Parkinson's disease subtypes (e.g. no cognitive impairment, Parkinson's with mild cognitive impairment, Parkinson's disease dementia) were selected. Effect sizes for group differentiation were calculated.

RESULTS

Out of 127 full-text articles reviewed, 48 tests were identified during the first literature search. In the second search, 1716 articles were reviewed and 23 papers selected. The strongest effect sizes for group discrimination were revealed for tests assessing executive function, attention, and visuo-cognitive abilities. Based on the results of the two literature searches, consensus guidelines were defined by the authors, allowing for Level-II diagnosis for Parkinson's with mild cognitive impairment and Parkinson's disease dementia.

CONCLUSIONS

The presented guidelines may have the potential to standardize and improve the neuropsychological assessment of Parkinson's disease patients in German speaking countries.

Phonemic fluency quantity and quality: Comparing patients with PSP, Parkinson's disease and focal frontal and subcortical lesions

Progressive supranuclear palsy (PSP) can be difficult to distinguish from Parkinson's disease (PD), but has a much graver prognosis. PSP is characterised severely reduced output on measures of phonemic fluency, suggesting that it may be a specific marker of PSP. However, reduced phonemic fluency has also been noted in PD, and very few studies have actually compared phonemic fluency in PSP and PD. Although anecdotal reports suggest that phonemic fluency output in PSP may have specific characteristics, with more low-frequency words and perseverative errors, no study to date has formally explored this. Further investigation into phonemic fluency output and its cognitive and neuroanatomical correlates is now critical for improving our understanding of the verbal fluency in PSP. In this study, we compared phonemic fluency characteristics (including quantity, frequency and error rates) in patients with PSP, PD and focal frontal or subcortical lesions, and age- and education-matched healthy controls. We then compared these characteristics with performance on extensive neuropsychological testing. We found that PSP patients generated significantly fewer words than patients with PD and patients with right frontal focal lesions, and healthy controls. Phonemic fluency was also significantly reduced in patients with left frontal and subcortical focal lesions. However, there were no significant group differences in word frequency or error rates. Phonemic fluency was best predicted by performance on the Vocabulary and Hayling neuropsychological tests. We argue that these findings provide important evidence that reduced phonemic fluency is a hallmark of PSP and argue that the specificity of this impairment betrays an underlying impairment in energization, reflecting dysfunction of left frontal and subcortical networks.

Application of the p9NORM correction method to timed neuropsychological tests in Parkinson's disease and multiple system atrophy

OBJECTIVE

Timed neuropsychological tests do not take into account physical impairment during scoring procedures. Dysarthria and upper limb impairment can be easily measured with the PATA rate test (PRT) and the nine-hole pegboard test (9HPT). We recently validated a normalization method for timed neuropsychological tests using the PRT and 9HPT (p9NORM). We now validate the p9NORM in Parkinson's disease (Yarnall et al. Neurology 82(4):308-316; 2014) and multiple system atrophy (MSA).

METHODS

We enrolled twenty-six patients with PD, eighteen patients with MSA, and fifteen healthy controls (HC). p9NORM was applied to patients with abnormal PRT and/or 9HPT. All subjects were tested with a comprehensive neuropsychological battery.

RESULTS

No differences emerged in demographics across groups: (PD: mean age ± SD 66 ± 8; education 9 ± 4 years; MSA: age 60 ± 8; education 10 ± 4 years; HC: age 61 ± 12; education 9 ± 4 years). In MSA patients, the scores on the trail making test (TMT-A p = 0.003; TMT-B p = 0.018), attentional matrices (AM; p = 0.042), and symbol digit modalities test (SDMT p = 0.027) significantly differed following application of p9NORM. In PD patients, the TMT-A (p < 0.001), TMT-B (p = 0.001), and AM (p = 0.001) differed after correction. PD and MSA showed cognitive impairment relative to HC performance. When comparing MSA with PD, the SDMT, AM, and fluencies were similar. TMT-A and -B raw scores were different between groups (p = 0.006; p = 0.034), but these differences lost significance after p9NORM corrections (p = 0.100; p = 0.186).

CONCLUSIONS

We confirm that the p9NORM can be successfully used in both PD and MSA patients, as it mitigates the impact of disability on timed tests, resulting in a more accurate analysis of cognitive domains.

Prediagnostic motor and non-motor symptoms in progressive supranuclear palsy: The step-back PSP study

BACKGROUND

Improved knowledge of the prediagnostic phase of progressive supranuclear palsy (PSP) might provide information on when and how the disease starts, along with the opportunity to test therapies in disease stages with lesser neurodegeneration.

OBJECTIVE

To explore the symptoms in years preceding the PSP diagnosis.

METHODS

This is a single-center retrospective case-control study based on clinical charts review and a structured interview to PSP patients and their caregivers. Prediagnostic symptoms were defined as those present more than one year before the diagnosis. We explored 35 symptoms in the following domains: visual, dizziness, motor, mood/apathy, cognitive, behavioral, sleep, gastrointestinal/urinary and miscellaneous. Non-parametric statistics were applied, with significance set at <0.05 (FDR-corrected).

RESULTS

We included 150 subjects: 50 PSP patients (38% females, age 75.8) and an age- and sex-matched control group of 50 Parkinson's disease (PD) and 50 subjects (CS) without neurodegenerative disease. The frequencies of visual, motor, cognitive, behaviour and dizziness domains were significantly higher in PSP vs. PD, and so were the motor, mood/apathy, cognitive, behaviour and dizziness ones in PSP vs. CS. Over 50% of prediagnostic falls, apathy and anxiety, depression and memory-attention-executive symptoms, and over 30% of gait disturbances started more than three and up to ten years before the diagnosis. PSP patients had more consultations to ENT and ophthalmologists than PD patients.

CONCLUSION

PSP patients present a broad variety of motor and non-motor symptoms several years before the diagnosis. The definition of a prediagnostic PSP phase might be helpful to identify patients in early disease stages.

Cognitive and behavioural dysfunctions in a patient with progressive supranuclear palsy (PSP)

Background

The aim of the case study was to describe the profile of cognitive and emotional functioning of a patient with possible progressive supranuclear palsy (PSP) from a longitudinal perspective.

Participants and procedure

This study involved an 71-year-old male patient diagnosed with PSP, and 9 matched healthy subjects. Neuro-psychological examination of the patient was performed twice with a 6 month interval. A set of neuropsycho-logical tests was used to assess both cognition and behaviour.

Results

Neuropsychological assessment revealed executive dysfunction dominance (planning deficits, reduced cogni-tive flexibility and abstract thinking, impulsiveness), reduced verbal fluency, psychomotor slowness and prob-lems with memory retrieval from the long-term memory storage in contrast to significantly better recognition of the previously learned information. According to emotional functioning, frontal change of personality was ob-served, with apathy, disinhibition, lack of insights, impulsiveness and “utilization behaviours”.

Conclusions

The profile of emotional and cognitive impairments met the criteria for dementia. There was a progression of deficits at visit two in comparison to visit one. The longitudinal perspective allowed the dynamics of emotional, cognitive and behavioural changes to be described over time: from depression related to initially preserved criticism of the illness to apathy and emotional blunting and behavioural frontal syndrome connected with the systematic loss of insight.

La belle indifférence revisited: a case report on progressive supranuclear palsy misdiagnosed as conversion disorder

BACKGROUND

Since the advent of computed tomography and magnetic resonance imaging scans, neurological disorders have less often been falsely labeled as conversion disorder (CD). However, misdiagnosis of a neurological disorder as CD still occurs, especially in cases with insidious onset. Misinterpretation of la belle indifférence may contribute to such misdiagnosis. Here, we describe a case of progressive supranuclear palsy/Richardson's syndrome (PSPS) misdiagnosed as a case of CD.

CASE

A 62-year-old woman consulted two different neurologists in 2012 because of falling spells since 2009 and was diagnosed with CD. She was referred to the Clinical Center of Excellence for Body, Mind, and Health for treatment of CD. After neurological examination, blood tests, and psychiatric examination, in which la belle indifférence and a history of incest were found, CD was confirmed. However, despite treatment for CD, the patient's physical symptoms deteriorated over a year. After repeated physical and psychiatric examinations, neurocognitive assessment, and consultation with a third neurologist because of suspicion of neurological disease, the patient was diagnosed with PSPS.

CONCLUSION

La belle indifférence may be a psychological sign in the context of CD, but it may also be an expression of lack of mimic due to Parkinsonism or of eye movement disorder in the context of neurological illness. A diagnosis of CD should not be considered definitive if no improvement occurs in terms of physical, mental, and cognitive symptoms despite appropriate therapy. In case of deterioration, neurological reexamination and reinterpretation of la belle indifférence should be considered.

Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) performance in progressive supranuclear palsy and multiple system atrophy

To determine if Montreal Cognitive Assessment (MoCA) is more sensitive than the commonly used Mini-Mental State Examination (MMSE) in detecting cognitive abnormalities in patients with probable progressive supranuclear palsy (PSP) and multiple system atrophy (MSA) compared with Parkinson's disease (PD). In this multicenter observational study, MMSE and MoCA were administered in a random order to 130 patients: 35 MSA, 30 PSP and 65 age, and education and gender matched-PD. We assessed between-group differences for MMSE, MoCA, and their subitems. Receiver-operating characteristic (ROC) curves were calculated. The mean MMSE was higher than the mean MoCA score in each MSA (27.7 ± 2.4 vs. 22.9 ± 3.0, p < 0.0001), PSP (26.0 ± 2.9 vs. 18.2 ± 3.9, p < 0.0001), and PD (27.3 ± 2.0 vs. 22.3 ± 3.5, p < 0.0001). MoCA total score as well as its letter fluency subitem differentiated PSP from MSA and PD with high specificity and moderate sensitivity. More specifically, a cut-off score of 7 F-words or less per minute would support a diagnosis of PSP (PSP vs. PD: 86 % specificity, 70 % sensitivity; PSP vs. MSA: 71 % specificity, 70 % sensitivity). By contrast, MMSE presented an overall ceiling effect for most subitems, except for the pentagon scores, where PSP did less well than MSA or PD patients. These preliminary results suggest that PSP and MSA, similar to PD patients, may present normal MMSE and reduced MoCA performance. Overall, MoCA is more sensitive than MMSE in detecting cognitive impairment in atypical parkinsonism and together with verbal fluency would be a useful test to support PSP diagnosis.

Comparison of regional brain atrophy and cognitive impairment between pure akinesia with gait freezing and Richardson's syndrome

Pure akinesia with gait freezing (PAGF) is considered a clinical phenotype of progressive supranuclear palsy. The brain atrophy and cognitive deficits in PAGF are expected to be less prominent than in classical Richardson's syndrome (RS), but this hypothesis has not been explored yet. We reviewed the medical records of 28 patients with probable RS, 19 with PAGF, and 29 healthy controls, and compared cortical thickness, subcortical gray matter volume, and neuropsychological performance among the three groups. Patients with PAGF had thinner cortices in frontal, inferior parietal, and temporal areas compared with controls; however, areas of cortical thinning in PAGF patients were less extensive than those in RS patients. In PAGF patients, hippocampal, and thalamic volumes were also smaller than controls, whereas subcortical gray matter volumes in PAGF and RS patients were comparable. In a comparison of neuropsychological tests, PAGF patients had better cognitive performance in executive function, visual memory, and visuospatial function than RS patients had. These results demonstrate that cognitive impairment, cortical thinning, and subcortical gray matter atrophy in PAGF patients resemble to those in RS patients, though the severity of cortical thinning and cognitive dysfunction is milder. Our results suggest that, PAGF and RS may share same pathology but that it appears to affect a smaller proportion of the cortex in PAGF.

Cognitive Impairment and Its Structural Correlates in the Parkinsonian Subtype of Multiple System Atrophy

BACKGROUND/AIMS

Previous studies indicate that patients with the parkinsonian subtype of multiple system atrophy (MSA-P) experience cognitive impairment. This study aimed to identify the existence of cognitive impairments and the different topographic patterns of morphological changes in MSA-P by means of imaging analysis, and also whether these morphological changes could be associated with cognitive dysfunctions in MSA-P.

METHODS

We recruited 15 nondemented probable MSA-P patients and 32 normal controls (NC) for neuropsychological testing and MRI. We analyzed morphological changes using cortical thickness analysis, voxel-based morphometry (VBM) and cerebellar volumetry. Multiple linear regression analysis was performed to evaluate the correlation of each cognitive score with the mean thickness of significant cortical-thinning clusters, mean gray-matter density of VBM clusters and cerebellar volume.

RESULTS

The scores on the Digit Span Test, the Seoul Verbal Learning Test (immediate and delayed), the phonemic Controlled Oral Word Association Test and the Stroop color test were significantly lower in the MSA-P group than in the NC group. We found two clusters exhibiting significant cortical thinning in the right paracentral lobule and parahippocampal gyrus. VBM analysis revealed significant gray-matter atrophy in the MSA-P group in the bilateral basal ganglia, cerebellum and temporal and frontal cortical areas. Multiple linear regression analysis demonstrated that cognitive dysfunction correlated significantly with thinning in the neocortex, cerebellum and striatum.

CONCLUSIONS

Our data demonstrate that cortical and cerebellar atrophy and striatal degeneration are associated with cognitive impairment in patients with MSA-P.

Car drivers with dementia: Different complications due to different etiologies?

OBJECTIVE

Older drivers with dementia are an at-risk group for unsafe driving. However, dementia refers to various etiologies and the question is whether dementias of different etiology have similar effects on driving ability.

METHODS

The literature on the effects of dementia of various etiologies on driving ability is reviewed. Studies addressing dementia etiologies and driving were identified through PubMed, PsychINFO, and Google Scholar.

RESULTS AND CONCLUSIONS

Early symptoms and prognoses differ between dementias of different etiology. Therefore, different etiologies may represent different likelihoods with regard to fitness to drive. Moreover, dementia etiologies could indicate the type of driving problems that can be expected to occur. However, there is a great lack of data and knowledge about the effects of almost all etiologies of dementia on driving. One could hypothesize that patients with Alzheimer's disease may well suffer from strategic difficulties such as finding a route, whereas patients with frontotemporal dementia are more inclined to make tactical-level errors because of impaired hazard perception. Patients with other dementia etiologies involving motor symptoms may suffer from problems on the operational level. Still, the effects of various etiologies of dementias on driving have thus far not been studied thoroughly. For the detection of driving difficulties in patients with dementia, structured interviews with patients but also their family members appear crucial. Neuropsychological assessment could support the identification of cognitive impairments. The impact of such impairments on driving could also be investigated in a driving simulator. In a driving simulator, strengths and weaknesses in driving behavior can be observed. With this knowledge, patients can be advised appropriately about their fitness to drive and options for support in driving (e.g., compensation techniques, car adaptations). However, as long as no valid, reliable, and widely accepted test battery is available for the assessment of fitness to drive, costly on-road test rides are inevitable. The development of a fitness-to-drive test battery for patients with dementia could provide an alternative for these on-road test rides, on condition that differences between dementia etiologies are taken into consideration.

Psychiatric issues in cognitive impairment

Neuropsychiatric symptoms (NPS) such as depression, hallucinations and apathy commonly occur in Parkinson's disease (PD) and have major clinical consequences including a negative impact on quality of life. This review discusses the epidemiology, clinical features, diagnostic procedures and treatment issues of NPS in PD and related disorders in the perspective of cognitive impairment, focusing on depression, anxiety, visual hallucinations, apathy, sleep disturbances, impulse control disorder and non-motor fluctuations. The majority of NPS are more common in PD patients with dementia, possibly related to shared underlying pathologies. Recent studies also suggest that NPS are associated with mild cognitive impairment in PD, in particular with the amnestic type. Accurate diagnosis of NPS is important but can be difficult, due to overlapping symptoms and similar appearance of symptoms of motor symptoms of parkinsonism, cognitive impairment, mood disorders and apathy. There are few systematic studies focusing on the management of NPS in PD with cognitive impairment.

Cognitive and sleep features of multiple system atrophy: review and prospective study

BACKGROUND

The profile and degree of cognitive impairment in Multiple System Atrophy (MSA) and the impact of sleep disorders, REM sleep behavior disorder (RBD) in particular, in parkinsonism-related cognitive deficits are currently being debated.

SUMMARY

We reviewed the cognitive, affective and sleep findings in MSA and also carried out a longitudinal investigation of 10 MSA patients. At the first evaluation, 3 patients showed isolated cognitive deficits. After a mean of 16 months, these patients remained unchanged, while 1 patient worsened from a normal condition. No significant differences emerged when the cognitive, affective and video-polysomnographic findings of MSA-P and MSA-C were compared. Depression was present in half of the patients, although it did not influence their cognitive performance. Comparisons between the first and second evaluation data showed significant worsening in visual attention and in ADL/IADL and UMSARS.

KEY MESSAGES

Isolated cognitive deficits are evidenced in a minority of MSA patients with the absence of a clear-cut diagnosis of dementia in the early stages of the disease. Attention and executive functions are often impaired. This study with a short follow-up period showed that RBD, although present in almost all patients affected by MSA, does not appear a clear early marker of cognitive impairment. Future longer-term studies with a larger patient sample are thus encouraged.

Cognitive impairment in multiple system atrophy: a position statement by the Neuropsychology Task Force of the MDS Multiple System Atrophy (MODIMSA) study group

Consensus diagnostic criteria for multiple system atrophy consider dementia as a nonsupporting feature, despite emerging evidence demonstrating that cognitive impairments are an integral part of the disease. Cognitive disturbances in multiple system atrophy occur across a wide spectrum from mild single domain deficits to impairments in multiple domains and even to frank dementia in some cases. Frontal-executive dysfunction is the most common presentation, while memory and visuospatial functions also may be impaired. Imaging and neuropathological findings support the concept that cognitive impairments in MSA originate from striatofrontal deafferentation, with additional contributions from intrinsic cortical degeneration and cerebellar pathology. Based on a comprehensive evidence-based review, the authors propose future avenues of research that ultimately may lead to diagnostic criteria for cognitive impairment and dementia associated with multiple system atrophy.

Impairment of brainstem implicit learning paradigms differentiates multiple system atrophy (MSA) from idiopathic Parkinson syndrome

OBJECTIVES

Learning as measured by eyeblink classical conditioning is preserved in patients with idiopathic Parkinson's disease, but severely affected in patients with progressive supranuclear palsy. We here sought to clarify whether procedural learning is impaired in multiple system atrophy (MSA), and whether it may be helpful for the differentiation of parkinsonian syndromes.

DESIGN

We investigated learning using (1) eyeblink classical conditioning with a delay (interstimulus interval 0 ms) and a trace (600 ms) paradigm and (2) a serial reaction time task.

SETTING

Participants were recruited from academic research centres.

PARTICIPANTS

11 patients with MSA and 11 healthy controls.

RESULTS

Implicit learning in eyeblink classical conditioning (acquisition of conditioned responses) as well as the serial reaction time task measures of implicit learning (reaction time change) are impaired in patients with MSA as compared with controls, whereas explicit learning as measured by the sequence recall of the serial reaction time task is relatively preserved.

ANALYSIS

We hypothesise that the learning deficits of patients with MSA are due to lesions of cerebellar and connected brainstem areas.

CONCLUSIONS

A retrospective synopsis of these novel data on patients with MSA and groups of patients with idiopathic Parkinson's disease and progressive supranuclear palsy studied earlier suggest that eyeblink classical conditioning may contribute to the early differentiation of atypical Parkinson syndromes from idiopathic Parkinson's disease. This hypothesis should be tested in a prospective trial.

What is measured with verbal fluency tests in Parkinson's disease patients at different stages of the disease?

Verbal fluency tests (VFT) are often used to assess executive functioning in Parkinson's disease (PD). Various cognitive functions may, however, impair performance on VFT. Furthermore, since PD is a progressive neurodegenerative disease, it is also not clear whether deficits on VFT reflect impairments in the same cognitive functions throughout the different disease stages. This study will investigate what is measured with VFT in PD, in particular at different disease stages. Eighty-eight PD patients and 65 healthy participants, matched for age, gender, and education, were included. All were assessed with semantic and phonemic VFT and tests assessing executive functions, memory, and psychomotor speed. Mild and moderate PD patients did not differ in the number of words generated on both VFT. However, mild and moderate PD patients differed significantly with regard to the size of the largest cluster and the number of intra-dimensional shifts on phonemic VFT. Furthermore, at the mild disease stages, psychomotor speed predicted the performance on both VFT; whereas at the moderate stages of the disease, cognitive flexibility and psychomotor speed predicted the performance on both VFT. In conclusion, different cognitive functions underlie the performances of PD patients at different stages of the disease on semantic and phonemic VFT. Impairments in VFT, therefore, do not necessarily represent a specific deficit of executive functioning in patients with PD but should rather be interpreted in the context of disease severity and dysfunctions in other domains of cognition.

Executive functioning in daily life in Parkinson's disease: initiative, planning and multi-task performance

Impairments in executive functioning are frequently observed in Parkinson's disease (PD). However, executive functioning needed in daily life is difficult to measure. Considering this difficulty the Cognitive Effort Test (CET) was recently developed. In this multi-task test the goals are specified but participants are free in their approach. This study applies the CET in PD patients and investigates whether initiative, planning and multi-tasking are associated with aspects of executive functions and psychomotor speed. Thirty-six PD patients with a mild to moderate disease severity and thirty-four healthy participants were included in this study. PD patients planned and demonstrated more sequential task execution, which was associated with a decreased psychomotor speed. Furthermore, patients with a moderate PD planned to execute fewer tasks at the same time than patients with a mild PD. No differences were found between these groups for multi-tasking. In conclusion, PD patients planned and executed the tasks of the CET sequentially rather than in parallel presumably reflecting a compensation strategy for a decreased psychomotor speed. Furthermore, patients with moderate PD appeared to take their impairments into consideration when planning how to engage the tasks of the test. This compensation could not be detected in patients with mild PD.

Cognitive impairments in multiple system atrophy of the cerebellar type

Background and Purpose

We investigated the cognitive profiles in a large sample of patients with multiple system atrophy-cerebellar ataxia (MSA-C) and compared directly them in patients with clinical diagnosis of probable MSA-C without dementia and control subjects with intact cognition.

Methods

We prospectively enrolled 26 patients with clinical diagnosis of probable MSA-C. All patients underwent a standardized neuropsychological test of the Seoul Neuropsychological Screening Battery.

Results

The score of Korean version of the Mini- Mental State Examination was significantly lower in patients with MSA-C (27.2 ± 2.5) than in control subjects (28.9 ± 1.0, p = 0.003). Patients with MSA-C showed a significantly worse performance in visuospatial function, 3 words recall, verbal immediate, delayed and recognition memory, visual delayed memory, phonemic and sementic Controlled Oral Word Association Test, and ideomotor praxis (p < 0.05).

Conclusions

Patients with MSA-C show more severe and more widespread cognitive dysfunctions than controls. Our results also indicate that cognitive dysfunction in patients with MCA-C is suggestive of disruption of the cerebellocortical circuits.

Differential effects of methylphenidate on problem solving in adults with ADHD

OBJECTIVE

Two studies were performed to assess both divergent and convergent thinking in adults with ADHD.

METHOD

The first study compared the problem-solving abilities of healthy participants (N = 144) and unmedicated adults with ADHD (N = 144). In the second study, problem-solving abilities of adults with diagnosed ADHD (N = 22) were examined twice, that is, on and off methylphenidate (MPH), and compared with the performance of a healthy control group (N = 22). Convergent thinking was measured using a Tower of London task, whereas divergent thinking was assessed using verbal fluency tasks.

RESULTS

Adults with ADHD off MPH displayed marked deficits of both divergent and convergent thinking. MPH treatment resulted in a marked improvement of convergent thinking, while no effect of medication was found regarding divergent thinking.

CONCLUSION

Pharmacological treatment of adults with ADHD revealed a differential effect of MPH on problem solving abilities.

Prevalence and correlates of neuropsychiatric symptoms in Parkinson's disease without dementia

A cross-sectional study of the profile of psychiatric symptoms and their relationships to medications, executive performance, and excessive daytime somnolence (EDS) was conducted on 1351 consecutive Parkinson's disease patients without dementia (PD-ND). Ratings were: neuropsychiatric inventory (NPI); hospital anxiety and depression scale (HADS); executive performance (semantic, phonemic, and alternating verbal fluencies); and the Epworth sleepiness scale (ESS). Eighty-seven percent of the subjects reported at least one psychiatric symptom. The most common were depression (70%), anxiety (69%), apathy (48%), and irritability (47%). Fifty percent of the patients had HADS-depression scores ranging from possible (8-10; 22%) to probable (>or=11; 28%) depression. Executive impairment was found in 41% and EDS in 26% of subjects. All considered variables were significantly more common with longer duration and more severe disease. Only depression appeared to be influenced by type of medication, being less prevalent among patients treated with DAs. Five NPI clusters were identified among patients scoring >or=1 on the NPI (87.3%): patients exhibiting predominantly apathy (12.7%), psychosis (3%), depression (13%), anxiety (15.6%), and "low-total NPI" (43.2%). Neuropsychiatric symptoms are common in nondemented PD patients suggesting that they are an integral part of PD from the beginning of the disease and appears more related to disease progression than to the type of antiparkinsonian medication. Apathy emerged as an independent construct in PD-ND, indicating the need to address specific therapeutical approaches targeted toward this particular symptom.

Clinical differential diagnosis of parkinsonism

Several clinical diagnostic criteria are available for differentiating Parkinson’s disease from the various forms of parkinsonism, but most clinical features have inadequate sensitivity and positive predictive value in the differential diagnosis of these conditions. Although a diagnosis of Parkinson’s disease can be a simple clinical exercise in typical patients with a positive response to dopaminergic treatment, the differential diagnosis versus other parkinsonian disorders can be challenging in some cases, particularly early in the disease. In this paper we have reviewed the motor and nonmotor clinical features that are helpful in the differential diagnosis of the most common forms of parkinsonism. A correct diagnosis in a parkinsonian patient is not simply an academic exercise, but it is crucial for planning any possible therapeutical intervention.

Treatment of dementia in parkinsonian syndromes with cholinesterase inhibitors

In Parkinsonian syndromes behavioural symptoms and dementia can be even more debilitating than motor symptoms and are an important predictor for nursing home placement and mortality. Neuropathologically, dementia seems to be primarily related to cortical changes rather than to subcortical alterations. Concerning neurotransmitter systems, the cholinergic system has been proposed to play a key role in cognitive disturbances. Based on studies with patients with Alzheimer disease, the application of cholinesterase inhibitors is vividly discussed also for dementia associated with parkinsonian syndromes. This review focuses on the specific symptoms of dementia in different parkinsonian syndromes and critically questions the effect of cholinergic treatment on cognitive functions in patients with extrapyramidal syndromes and dementia. There is evidence that medication with some cholinesterase inhibitors can enhance cognition as well as activities of daily living in dementia with Parkinson's disease and seems to reduce behavioural disturbances in both dementia with Parkinson's disease and dementia with Lewy bodies. The effect of treatment with cholinesterase inhibitors in progressive supranuclear palsy and corticobasal degeneration warrants carefully designed studies including a sufficient number of patients and symptom-adopted dementia scales.

Neurodegenerative disorders mimicking progressive supranuclear palsy: a report of three cases

Progressive supranuclear palsy (PSP) is rarely confused with other parkinsonian disorders once the vertical gaze palsy appears. Corticobasal degeneration is the most common differential diagnostic entity. We describe three cases diagnosed during life as PSP but found to have another neurologic disorder at autopsy. No explanation for the gaze palsies was found in any case.

Can the frontal assessment battery (FAB) differentiate bradykinetic rigid syndromes? Relation of the FAB to formal neuropsychological testing

The frontal assessment battery (FAB) is a bedside test of executive function. It takes less than 10 minutes to administer and a low score indicates executive dysfunction. To determine whether the FAB could detect the more severe subcortical dementia that is a feature of PSP and differentiate it from other bradykinetic rigid syndromes, we studied 17 patients with progressive supranuclear palsy (PSP); 11 with multiple system atrophy (MSA) and 12 with Parkinson's disease (PD). We compared FAB scores with the results of more detailed tests of executive and general cognitive function.FAB scores were significantly lower in PSP than in MSA or PD (p=0.02 and p<0.001) and were also found to be significantly lower in MSA than in PD (p=0.047). We divided the study group into those with an FAB score <15 and those with an FAB score>/=5, regardless of the clinical diagnosis. While 82% of the PSP group had FAB scores of <15, such scores were recorded in only 36% of the MSA and 8% of the PD groups. The lexical fluency and motor series subscores of the FAB discriminated 70% of the PSP, MSA and PD patients. The FAB scores correlated with tests of executive function, as well as with scores on the Mattis Dementia Rating Scale, the Mini Mental State Examination and other tests of general cognitive function. A stepwise regression analysis revealed that across the groups, among the variables that correlated with FAB scores, alternating semantic fluency accounted for 80% of FAB variance.These results suggest that the FAB is a valid and easily applicable bedside test to discriminate executive dysfunction in these three frequently confused bradykinetic rigid syndromes.

Cognitive and behavioral aspects of PSP since Steele, Richardson and Olszewski's description of PSP 40 years ago and Albert's delineation of the subcortical dementia 30 years ago

Although researchers are now familiar with progressive supranuclear palsy (PSP) and its characteristic "subcortical" dementia, this was not the case prior to seminal descriptions by Steele, Richardson, Olszewski and Albert. In fact, the first three authors identified this disorder, and the last one introduced the classification of the dementias according to the anatomical involvement. This paper is in honor of their contributions, and will also outline the changes that have occurred since their seminal works.