Clinical variables and biomarkers in prediction of cognitive impairment in patients with newly diagnosed Parkinson's disease: a cohort study

Summary

Background

Parkinson's disease is associated with an increased incidence of cognitive impairment and dementia. Predicting who is at risk of cognitive decline early in the disease course has implications for clinical prognosis and for stratification of participants in clinical trials. We assessed the use of clinical information and biomarkers as predictive factors for cognitive decline in patients with newly diagnosed Parkinson's disease.

Methods

The Parkinson's Progression Markers Initiative (PPMI) study is a cohort study in patients with newly diagnosed Parkinson's disease. We evaluated cognitive performance (Montreal Cognitive Assessment [MoCA] scores), demographic and clinical data, APOE status, and biomarkers (CSF and dopamine transporter [DAT] imaging results). Using change in MoCA scores over 2 years, MoCA scores at 2 years' follow-up, and a diagnosis of cognitive impairment (combined mild cognitive impairment or dementia) at 2 years as outcome measures, we assessed the predictive values of baseline clinical variables and separate or combined additions of APOE status, DAT imaging, and CSF biomarkers. We did univariate and multivariate linear analyses with MoCA change scores between baseline and 2 years, and with MoCA scores at 2 years as dependent variables, using backwards linear regression analysis. Additionally, we constructed a prediction model for diagnosis of cognitive impairment using logistic regression analysis.

Findings

390 patients with Parkinson's disease recruited between July 1, 2010, and May 31, 2013, and for whom data on MoCA scores at baseline and 2 years were available. In multivariate analyses, baseline age, University of Pennsylvania Smell Inventory Test (UPSIT) scores, CSF amyloid — (Aβ42) to t-tau ratio, and APOE status were associated with change in MoCA scores over time. Baseline age, MoCA and UPSIT scores, and CSF Aβ42 to t-tau ratio were associated with MoCA score at 2 years (using a backwards p-removal threshold of 0·1). Accuracy of prediction of cognitive impairment using age alone (area under the curve 0·68, 95% CI 0·60–0·76) significantly improved by addition of clinical scores (UPSIT, Rapid Eye Movement Sleep Behaviour Disorder Screening Questionnaire [RBDSQ], Geriatric Depression Scale, and Movement Disorder Society Unified Parkinson's Disease Rating Scale motor scores; 0·76, 0·68–0·83), CSF variables (0·74, 0·68–0·81), or DAT imaging results (0·76, 0·68–0·83). In combination, the five variables showing the most significant associations with cognitive impairment (age, UPSIT, RBDSQ, CSF Aβ42, and caudate uptake on DAT imaging) allowed prediction of cognitive impairment at 2 years (0·80, 0·74–0·87; p=0·0003 compared to age alone).

Interpretation

In newly diagnosed Parkinson's disease, the occurrence of cognitive impairment at 2 year follow-up can be predicted with good accuracy using a model combining information on age, non-motor assessments, DAT imaging, and CSF biomarkers.

Lancet Neurology 2016

Treatment of neurosarcoidosis A comparative study of methotrexate and mycophenolate mofetil

ABSTRACT

Objective: To compare the efficacy of methotrexate (MTX) and mycophenolate mofetil (MMF) in the prevention of relapses in neurosarcoidosis.

Methods: We conducted a retrospective multicenter study including patients who received MTX or MMF for the treatment of histologically proven neurosarcoidosis. The efficacy of the immunosuppressive drug was assessed by determining the time to relapse.

Results: Forty patients with a diagnosis of neurosarcoidosis (24 men, 16 women, median age at diagnosis 43.5 years) who received at least 3 months of MTX (n = 32) or MMF (n = 14) were included. The immunosuppressive drug was always associated with steroids. The rate of relapse was 47% in the MTX group (0.2 relapses per year of exposure) and 79% in the MMF group (0.6 relapses per year of exposure) (p = 0.058). The median time to relapse was significantly shorter in the MMF group (11 months) compared with the MTX group (28 months) (p = 0.049). Adverse events occurred in 11 patients during MTX therapy and in 1 patient during MMF therapy (p = 0.12).

Conclusions: Relapses of neurosarcoidosis occur frequently, despite the use of an immunosuppressive drug in addition to corticosteroids. MTX significantly increases the survival time without relapse compared to MMF and should be preferred over MMF for the treatment of neurosarcoidosis. This study provides Class IV evidence that for patients with neurosarcoidosis taking steroids, MTX is superior to MMF in reducing the risk of relapse.

Neurology 2016

Revisiting neurofibromatosis type 2 diagnostic criteria to exclude LZTR1-related schwannomatosis

ABSTRACT

Objective: To determine the specificity of the current clinical diagnostic criteria for neurofibromatosis type 2 (NF2) relative to the requirement for unilateral vestibular schwannoma (VS) and at least 2 other NF2-related tumors.

Methods: We interrogated our Manchester NF2 database, which contained 205 individuals meeting NF2 criteria who initially presented with a unilateral VS. Of these, 83 (40.7%) went on to develop a contralateral VS. We concentrated our genetic analysis on a group of 70 who initially fulfilled NF2 criteria with a unilateral vestibular schwannoma and at least 2 additional nonintradermal schwannomas.

Results: Overall, 5/70 (7%) individuals with unilateral VS and at least 2 other schwannomas had a pathogenic or likely pathogenic LZTR1 mutation. Twenty of the 70 subsequently developed bilateral disease. Of the remaining 50, 5 (10%) had a germline LZTR1 mutation, equivalent to the number (n = 5) with a germline NF2 mutation.

Conclusions: The most common etiology for unilateral VS and 2 additional NF2-associated tumors in this cohort was mosaic NF2. Germline LZTR1 and germline NF2 mutations were equally common in our cohort. This indicates that LZTR1 must be considered when making a diagnosis of NF2 in the presence of unilateral VS in individuals without a germline NF2 mutation.

Neurology 2016

Practice guideline summary: Treatment of restless legs syndrome in adults Report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology

Objective: To make evidence-based recommendations regarding restless legs syndrome (RLS) management in adults.

Methods: Articles were classified per the 2004 American Academy of Neurology evidence rating scheme. Recommendations were tied to evidence strength.

Results and recommendations: In moderate to severe primary RLS, clinicians should consider prescribing medication to reduce RLS symptoms. Strong evidence supports pramipexole, rotigotine, cabergoline, and gabapentin enacarbil use (Level A); moderate evidence supports ropinirole, pregabalin, and IV ferric carboxymaltose use (Level B). Clinicians may consider prescribing levodopa (Level C). Few head-to-head comparisons exist to suggest agents preferentially. Cabergoline is rarely used (cardiac valvulopathy risks). Augmentation risks with dopaminergic agents should be considered. When treating periodic limb movements of sleep, clinicians should consider prescribing ropinirole (Level A) or pramipexole, rotigotine, cabergoline, or pregabalin (Level B). For subjective sleep measures, clinicians should consider prescribing cabergoline or gabapentin enacarbil (Level A), or ropinirole, pramipexole, rotigotine, or pregabalin (Level B). For patients failing other treatments for RLS symptoms, clinicians may consider prescribing prolonged-release oxycodone/naloxone where available (Level C). In patients with RLS with ferritin ≤75 μg/L, clinicians should consider prescribing ferrous sulfate with vitamin C (Level B). When nonpharmacologic approaches are desired, clinicians should consider prescribing pneumatic compression (Level B) and may consider prescribing near-infrared spectroscopy or transcranial magnetic stimulation (Level C). Clinicians may consider prescribing vibrating pads to improve subjective sleep (Level C). In patients on hemodialysis with secondary RLS, clinicians should consider prescribing vitamin C and E supplementation (Level B) and may consider prescribing ropinirole, levodopa, or exercise (Level C).

Neurology 2016

Computed tomography based quantification of lesion water uptake identifies patients within 4.5 hours of stroke onset: A multicenter observational study

Objective: Many patients with stroke cannot receive intravenous thrombolysis because the time of symptom onset is unknown. We tested whether computed tomography (CT) based quantification of water uptake in the ischemic tissue can identify patients with stroke onset within 4.5 hours, the time window of thrombolysis.

Methods: Perfusion CT was used to identify ischemic brain tissue, its density was measured in native CT and related to the density of the corresponding area of the contralateral hemisphere to quantify lesion water uptake. The optimal cut-off value of water uptake distinguishing stroke onset within and beyond 4.5 hours was calculated in patients with proximal middle cerebral artery occlusion (derivation cohort) with known time of symptom onset. The so derived cut-off value was validated in a prospective cohort from other stroke centers.

Results: Of 178 patients of the derivation cohort, 147 (82.6%) had CT within 4.5 hours. Percent water uptake was significantly lower in patients with stroke onset within compared to beyond 4.5 hours. The area under the receiver-operating characteristic curve for distinguishing these patient groups according to percent water uptake was 0.999 (95% confidence interval, 0.996-1.000, P<0.001) with an optimal cut-off value of 11.5%. Applying this cut-off to the validation cohort of 240 patients, sensitivity was 98.6%, specificity 90.5%, positive predictive value 99.1%, and negative predictive value 86.4%.

Interpretation: Quantification of brain water uptake identifies stroke patients with symptom onset within 4.5 hours with high accuracy and may guide the decision to use thrombolysis in patients with unknown time of stroke onset.

Annals Of Neurology 2016

The central vein sign and its clinical evaluation for the diagnosis of multiple sclerosis: a consensus statement from the North American Imaging in Multiple Sclerosis Cooperative

Over the past few years, MRI has become an indispensable tool for diagnosing multiple sclerosis (MS). However, the current MRI criteria for MS diagnosis have imperfect sensitivity and specificity. The central vein sign (CVS) has recently been proposed as a novel MRI biomarker to improve the accuracy and speed of MS diagnosis. Evidence indicates that the presence of the CVS in individual lesions can accurately differentiate MS from other diseases that mimic this condition. However, the predictive value of the CVS for the development of clinical MS in patients with suspected demyelinating disease is still unknown. Moreover, the lack of standardization for the definition and imaging of the CVS currently limits its clinical implementation and validation. On the basis of a thorough review of the existing literature on the CVS and the consensus opinion of the members of the North American Imaging in Multiple Sclerosis (NAIMS) Cooperative, this article provides statements and recommendations aimed at helping radiologists and neurologists to better understand, refine, standardize and evaluate the CVS in the diagnosis of MS.

Nature Reviews Neurology 2016

Association Between Metabolic Syndrome Components and Polyneuropathy in an Obese Population

Abstract

Importance  Past studies have shown an association between metabolic syndrome and polyneuropathy, but the precise components that drive this association remain unclear.

Objectives  To determine the prevalence of polyneuropathy stratified by glycemic status in well-characterized obese and lean participants and investigate the association of specific components of metabolic syndrome with polyneuropathy.

Design, Setting, and Participants  We performed a cross-sectional, observational study from November 1, 2010, to December 31, 2014, in obese participants (body mass index [calculated as weight in kilograms divided by height in meters squared] of 35 or more with no comorbid conditions or 32 or more with at least 1 comorbid condition) from a weight management program and lean controls from a research website. The prevalence of neuropathy, stratified by glycemic status, was determined, and a Mantel–Haenszel χ² test was used to investigate for a trend. Logistic regression was used to model the primary outcome of polyneuropathy as a function of the components of metabolic syndrome after adjusting for demographic factors. Participants also completed quantitative sudomotor axon reflex testing, quantitative sensory testing, the neuropathy-specific Quality of Life in Neurological Disorders instrument, and the short-form McGill Pain Questionnaire.

Exposures  Components of metabolic syndrome (as defined by the National Cholesterol Education Program Adult Treatment Panel III), including glycemic status (as defined by the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus).

Main Outcomes and Measures  Toronto consensus definition of probable polyneuropathy. Secondary outcomes included intraepidermal nerve fiber density and nerve conduction study parameters.

Results  We enrolled 102 obese participants (mean [SD] age, 52.9 [10.2] years; 48 men and 54 women; 45 with normoglycemia [44.1%], 31 with prediabetes [30.4%], and 26 with type 2 diabetes [25.5%]) and 53 lean controls (mean [SD] age, 48.5 [9.9] years; 16 men and 37 women). The prevalence of polyneuropathy was 3.8% in lean controls (n = 2), 11.1% in the obese participants with normoglycemia (n = 5), 29% in the obese participants with prediabetes (n = 9), and 34.6% in the obese participants with diabetes (n = 9) (P < .01 for trend). Age (odds ratio, 1.09; 95% CI, 1.02-1.16), diabetes (odds ratio, 4.90; 95% CI, 1.06-22.63), and waist circumference (odds ratio, 1.24; 95% CI, 1.00-1.55) were significantly associated with neuropathy in multivariable models. Prediabetes (odds ratio, 3.82; 95% CI, 0.95-15.41) was not significantly associated with neuropathy.

Conclusions and Relevance  The prevalence of polyneuropathy is high in obese individuals, even those with normoglycemia. Diabetes, prediabetes, and obesity are the likely metabolic drivers of this neuropathy.

JAMA Neurology 2016