Cerebral Phosphorus Magnetic Resonance Spectroscopy in a Patient with Giant Cell Arteritis and Endovascular Therapy.

With phosphorus magnetic resonance spectroscopy (31P MRS) energy metabolites can be visualised. In this case study, we report on a patient with stenosis and wall contrast enhancement in the left internal carotid and the right vertebral artery, due to giant cell arteritis. 31P MRS revealed a decreased inorganic phosphate-to-phosphocreatine ratio (Pi/PCr) in regions with a prolonged mean transit time (MTT). After systemic therapy and angioplasty of the right vertebral artery, the stenosis and the symptoms improved and the area of prolonged MTT became smaller. However, a new decrease in Pi/PCr in areas that developed moderately prolonged MTT was observed.

Consistency of "Probable RBD" Diagnosis with the RBD Screening Questionnaire: A Follow-up Study.

INTRODUCTION: The aim of this study was to evaluate the consistency of "probable RBD" diagnosis with the RBD screening questionnaire (RBDSQ) assessed 2 years apart in a population-based study. METHODS: Probable RBD was assessed by RBDSQ in 2008 and in 2010 in the Bruneck Study Cohort, with participants aged ≥60 years. RESULTS: A total of 437 participants completed the RBDSQ in 2008 and 2010. There were 29 (6.6%) and 23 (5.3%) participants with probable RBD in 2008 and in 2010, respectively. Only eight (1.8%) screened positive on both occasions. RBDSQ values 2 years apart showed low correlation with each other (Spearman rank coefficient r = 0.348, P < 0.001) and low agreement (intraclass correlation coefficient 0.388, P < 0.001). CONCLUSIONS: We found low agreement between the two assessments. Possible explanations are the fluctuation of untreated RBD expression and the poor utility of the RBDSQ to detect RBD in the general population. Until further PSG validation of the RBDSQ in population-based studies, investigators must be aware of the inherent uncertainty of questionnaire-based RBD diagnosis.

Prodromal Parkinson's disease as defined per MDS research criteria in the general elderly community.

BACKGROUND: Recently, the International Parkinson and Movement Disorder Society has defined research criteria for prodromal Parkinson's disease (PD), but to date their predictive value has not yet been tested in population-based cohorts. METHODS: We retrospectively applied these criteria to the longitudinal Bruneck Study cohort aged 55-94 years using recorded data on all included risk and prodromal markers that are quick and easily assessable. RESULTS: After excluding participants with idiopathic PD or secondary parkinsonism, prevalence of probable prodromal PD in the remaining 539 participants was 2.2% (95% confidence interval, 1.2%-3.9%). Of 488 participants followed up over 5 years, 11 developed incident PD. Sensitivity of "probable prodromal PD" status for incident PD was 54.6% (95% confidence interval, 28.0%-78.8%), specificity was 99.2% (97.8%-99.8%), positive predictive value was 60.0% (31.2%-83.3%), and negative predictive value was 99.0% (97.5%-99.6%). CONCLUSIONS: Our findings suggest that the new research criteria for prodromal PD are a promising tool to identify cases of incident PD over 5 years, arguing for their usefulness in defining target populations for disease-prevention trials. © 2016 International Parkinson and Movement Disorder Society.

Left hemispheric predominance of nigrostriatal dysfunction in Parkinson's disease.

The aim of this study was to investigate the distribution and the degree of asymmetric putaminal dopamine transporter availability in right-handed patients with Parkinson's disease and its association with the severity of lateralized motor signs. Asymmetry of motor symptoms was defined by the difference between right- and left-sided scores for lateralized items assessed by the Unified Parkinson's Disease Rating Scale Motor Score in a series of 68 patients with Parkinson's disease (disease duration 2.1 ± 1.5 years; Unified Parkinson's Disease Rating Scale Motor Score 22.7 ± 9). Putaminal dopamine transporter availability was measured with the radioligand [(123)I]ß-carboxymethyoxy-3 -ß-(4-iodophenyl) tropane ([(123)I]ß-CIT) and single photon emission computed tomography. We found that in the right-handed Parkinson's disease cohort, the number of patients who had lower dopamine transporter uptake in the left posterior putamen was significantly greater compared with those with lower uptake in the right posterior putamen (Parkinson's disease-left group, n = 49; Parkinson's disease-right group, n = 19; P < 0.001). In addition, one-way analysis of variance revealed significant reductions of mean total putaminal [(123)I]ß-CIT binding of the Parkinson's disease-right patients compared with Parkinson's disease-left patients (P < 0.05).The preponderance of reduced left putaminal dopamine transporter availability strengthens clinical observations of a greater proportion of right-handed patients with Parkinson's disease with predominantly right-sided motor signs and argues against a randomly distributed asymmetric vulnerability of substantia nigra dopaminergic neurons. The coexistence of a subgroup of right-handed patients with Parkinson's disease with more severe and predominant ipsilateral putaminal dopamine transporter decline suggests that asymmetry of dopaminergic denervation and motor dysfunction in Parkinson's disease cannot be fully explained by hemispheric dominance alone, but that other factors must be involved.

Diffusion weighted imaging best discriminates PD from MSA-P: A comparison with tilt table testing and heart MIBG scintigraphy.

Both diffusion weighted magnetic resonance imaging (DWI) of the basal ganglia and meta-iodobenzylguanidin (MIBG) scintigraphy of the heart have been reported useful in the differential diagnosis of patients with Parkinson's disease (PD) vs. the parkinson variant of multiple system atrophy (MSA-P). Their diagnostic value, however, has never been directly compared in patients with parkinsonism and autonomic dysfunction. We have studied 9 patients with PD and 9 patients with MSA-P matched for age and disease severity. Regional trace of the diffusion tensor values were determined in the putamina. Cardiac MIBG uptake was quantified by comparing regions of interest over heart and mediastinum Heart/Mediastinum (H/M) ratio. Furthermore, all patients underwent tilt testing. PD patients showed significantly lower H/M ratios than normal controls; however, there was considerable overlap between the two patient groups. We did not detect any significant differences of blood pressure response to passive tilt between the two patient groups. Sensitivity of MIBG scintigraphy versus DWI for the differentiation of MSA-P from PD was 55.6% vs. 100%, specificity 88.8% vs. 100%, and area under the curve 0.802 vs. 1.000. Our data suggest that DWI is superior to both tilt table testing and MIBG scintigraphy in the differential diagnosis of PD versus MSA-P.

Topography of dopamine transporter availability in progressive supranuclear palsy: a voxelwise [123I]beta-CIT SPECT analysis.

BACKGROUND: Dopaminergic loss can be visualized by means of iodine I 123-labeled 2beta-carbomethoxy-3beta-(4-iodophenyl)tropane ([(123)I]beta-CIT) single-photon emission computed tomography (SPECT) in several neurodegenerative parkinsonian disorders. Most previous SPECT studies have adopted region-of-interest methods for analysis, which are subjective and operator dependent. OBJECTIVE: To objectively localize the cerebral dopamine transporter status in the early stages of progressive supranuclear palsy (PSP). DESIGN: Prospective study. SETTING: Parkinson disease outpatient clinic. PATIENTS: Fourteen patients with PSP, 17 with Parkinson disease (PD), 15 with Parkinson-variant multiple-system atrophy (MSA-P), and 13 healthy control subjects, matched for age and disease duration. INTERVENTIONS: Statistical parametric mapping applied to [(123)I]beta-CIT SPECT. MAIN OUTCOME MEASURES: Differences in [(123)I]beta-CIT uptake. RESULTS: All patients with the different parkinsonian disorders showed a significant decrease in striatal [(123)I]beta-CIT uptake without any overlap with the control group. In patients with MSA-P and PSP, an additional reduction in brainstem [(123)I]beta-CIT signal compared with controls and patients with PD was identified with statistical parametric mapping. Midbrain [(123)I]beta-CIT uptake discriminated atypical parkinsonian disorders from PD with an overall correct classification of 91.3%. On the other hand, [(123)I]beta-CIT SPECT failed to discriminate PSP and MSA-P. CONCLUSION: By applying statistical parametric mapping to [(123)I]beta-CIT SPECT images of patients with PSP, a widespread decline of monoaminergic transporter availability including the striatum and brainstem was localized in PSP, discriminating patients with PSP from patients with PD, but not from those with MSA-P. Quantification of midbrain dopamine transporter signal may therefore enhance the utility of SPECT imaging in the differential diagnosis of patients with parkinsonism.

Seminar on choreas.

Chorea is one of the major types of involuntary movement disorders originating from dysfunctional neuronal networks interconnecting the basal ganglia and frontal cortical motor areas. The syndrome is characterised by a continuous flow of random, brief, involuntary muscle contractions and can result from a wide variety of causes. Diagnostic work-up can be straightforward in patients with a positive family history of Huntington's disease or acute-onset hemichorea in patients with lacunar stroke, but it can be a challenging and complex task in rare autoimmune or genetic choreas. Principles of management focus on establishing an aetiological classification and, if possible, removal of the cause. Preventive strategies may be possible in Huntington's disease where genetic counselling plays a major part. In this review we summarise the current understanding of the neuroanatomy and pathophysiology of chorea, its major aetiological classes, and principles of diagnostic work-up and management.

Parkinson's disease and arithmetics: the role of executive functions.

Brain imaging studies as well as neuropsychological case studies suggest an important role for basal ganglia in arithmetic processing. Aim of this study was to assess possible numerical deficits in PD and functional relations between numerical and other cognitive deficits. Fifteen non-demented patients with early PD (stable responders treated by l-dopa) were compared to 28 healthy age and education matched controls. Both groups underwent a neuropsychological assessment focussing on numerical abilities (quantity processing, arithmetic fact retrieval, complex mental and written calculation, transcoding, arithmetic set-shifting, calculation span), working memory and executive functions. Patients with PD showed deficits in complex mental calculation and calculation span tasks. Results of this study suggest that impairments in working memory as well as in executive functions, such as inhibition of interference, lead to secondary deficits in numerical processing. The study contributes to better understanding the specific cognitive deficits in early PD and the neurocognitive architecture of arithmetic processing.

Diffusion-weighted imaging in Huntington's disease.

Huntington's disease (HD) is an autosomal dominant progressive neurodegenerative disorder that results from an expanded trinucleotide (CAG) repeat on the huntingtin gene. Neurodegeneration in HD affects most prominently the basal ganglia. Therefore, diffusivity was obtained in the basal ganglia and thalamus of 29 patients with early HD and 27 healthy volunteers by means of the trace of the diffusion tensor (Trace(D)). Putaminal, caudate, pallidal, and thalamic Trace(D) values were increased in patients with HD compared with controls. Increased diffusivity in the putamen and caudate nucleus correlated with global functional impairment, CAG repeat length, as well as bicaudate ratio. Diffusion-weighted imaging appears to be a promising surrogate marker for disease severity in HD. Sensitivity to change remains to be established longitudinally.

Topography of putaminal degeneration in multiple system atrophy: a diffusion magnetic resonance study.

There is neuropathologic evidence that, in early stages of the Parkinson variant of multiple system atrophy (MSA-P), the putamen shows a distinct topographical pathology affecting predominantly the dorsolateral and caudal regions while leaving the rostral to midparts almost intact. We investigated the topographic profile of putaminal degeneration in MSA-P patients in vivo by means of diffusion-weighted imaging (DWI), which has been shown to reveal abnormalities in the basal ganglia of patients with MSA-P compared to patients with PD and healthy controls. For this purpose, regional trace of the diffusion tensor (rTrace(D)) values were determined in the entire, anterior, and posterior putamen in 15 patients with probable MSA-P, in 20 patients with PD, and in 11 healthy volunteers matched for age and disease duration. MSA-P patients had significantly higher rTrace(D) values in entire, anterior, and posterior putamen compared to both controls and PD patients. Trace(D) values were significantly higher in the posterior compared to the anterior putamen in the MSA-P group. There were no significant differences between posterior and anterior putamen in both the control and PD group. Our study demonstrates prominent involvement of the posterior putamen in early disease stages of MSA-P in vivo by assessing putaminal diffusivity with the help of DWI.

Progression of putaminal degeneration in multiple system atrophy: a serial diffusion MR study.

By using diffusion-weighted imaging (DWI), we have recently shown abnormal diffusivity in the putamen of patients with the Parkinson variant of multiple system atrophy (MSA-P) which also correlated with disease severity, indicating the capability of putaminal diffusivity to serve as a marker for disease progression. We therefore performed a serial DWI study in 10 patients with MSA-P compared to 10 patients with Parkinson's disease (PD) to evaluate the dynamic evolution of diffusion properties in the basal ganglia including putamen, caudate nucleus and globus pallidum by means of the trace of the diffusion tensor (Trace(D)). For comparison, we have also analyzed the frequency and semiquantitative grading of MSA-P-related structural changes on conventional MRI including putaminal atrophy, lateral hyperintense margination of the putamen and putaminal signal hypointensity relative to the globus pallidum on T2 MR images. None of the Trace(D) values in the basal ganglia regions in the PD group changed significantly at follow-up compared to baseline. In MSA-P, a significant increase of the Trace(D) was found in the putamen, which correlated with motor progression as assessed by the Unified Parkinson's Disease Rating Scale (UPDRS). No significant change of any of the abnormal putaminal findings on routine MRI was obtained. We suggest that abnormal diffusivity in the putamen is sensitive to change over time in MSA-P and correlates with motor progression indicating that DWI may serve to monitor disease progression in MSA-P in an objective and quantitative manner.

Trace of diffusion tensor differentiates the Parkinson variant of multiple system atrophy and Parkinson's disease.

We have recently shown that diffusion-weighted magnetic resonance (MR) imaging (DWI) discriminates patients with the Parkinson variant of multiple system atrophy (MSA-P) from those with Parkinson's disease (PD) by regional apparent diffusion coefficients (rADC) in the putamen. Because rADCs measured in one direction may underestimate diffusion-related pathologic processes, we investigated the diffusivity in different brain areas by trace of diffusion tensor (Trace(D)) in a new cohort of patients with MSA-P and PD. We studied 11 MSA-P, 17 PD patients, and 10 healthy volunteers matched for age and disease duration. Regional ADCs in three orthogonal directions and Trace(D) values were determined in selected brain regions including the basal ganglia, gray matter, white matter, substantia nigra, and pons. MSA-P patients had significantly higher putaminal and pallidal rTrace(D) values as well as rADCs in y- and z-direction than both PD patients and healthy volunteers. Moreover, putaminal Trace(D) discriminated completely MSA-P from both PD and healthy volunteers. The rADCs in the y- and z-direction provided a complete or near complete separation. In conclusion, our study confirms the results of previous studies of our group that patients with MSA-P show an increased putaminal diffusivity due to neuronal loss and gliosis. Because rADCs in one direction are dependent on the slice orientation relative to the directions of fiber tracts, Trace(D) imaging appears to be more accurate in the separation of MSA-P from PD.