Effects of immediate thrombolytic treatment in imaging area on functional outcome in patients with acute ischemic stroke.

INTRODUCTION: Door-to-needle time (DNT) is an established predictor of outcome in acute ischemic stroke (AIS) patients treated with intravenous thrombolysis (IVT). Several strategies have been proposed to streamline in-hospital pathways, among which treatment at CT/MR bed. AIM: To explore the impact of treatment at CT/MR bed, here defined as imaging area (IA), on functional outcome in stroke patients treated with IVT alone. METHODS: All AIS patients treated with IVT alone at our center in 2020, 2021, and 2022 were included. Patients with any previous disability were excluded. The cohort was divided into two groups, depending on the treatment site. One group received IVT at IA, the other at emergency room or stroke unit (non-IA). Regression analysis assessed the association between treatment site and 3-month outcome. RESULTS: A total of 327 patients who received IVT alone were included in the analysis. One hundred thirty-three (40.7%) were in the IA group and 194 (59.3%) in the non-IA group. The groups showed similar baseline characteristics. In the IA group, DNT was 45 min shorter. Despite similar rates of functional independence (mRS 0-2), the IA group showed higher rates of excellent outcome (mRS 0-1) compared to the non-IA group (60.1% vs 42.8%, p<0.01). Immediate treatment at IA was independently associated to excellent outcome (OR 1.78 [1.03-3.08]). CONCLUSIONS: Thrombolytic treatment at IA lowers DNT and is an independent predictor of excellent outcome after AIS. Our study emphasizes the importance of immediate thrombolytic treatment at IA, soon after radiological eligibility is confirmed. Immediate treatment at IA should be a standard-of-care for AIS.

A metabolomic signature of treated and drug-naïve patients with Parkinson's disease: a pilot study.

INTRODUCTION: About 90% of cases of Parkinson's disease (PD) are idiopathic and attempts to understand pathogenesis typically assume a multifactorial origin. Multifactorial diseases can be studied using metabolomics, since the cellular metabolome reflects the interplay between genes and environment. OBJECTIVE: The aim of our case-control study is to compare metabolomic profiles of whole blood obtained from treated PD patients, de-novo PD patients and controls, and to study the perturbations correlated with disease duration, disease stage and motor impairment. METHODS: We collected blood samples from 16 drug naïve parkinsonian patients, 84 treated parkinsonian patients, and 42 age matched healthy controls. Metabolomic profiles have been obtained using gas chromatography coupled to mass spectrometry. Multivariate statistical analysis has been performed using supervised models; partial least square discriminant analysis and partial least square regression. RESULTS: This approach allowed separation between discrete classes and stratification of treated patients according to continuous variables (disease duration, disease stage, motor score). Analysis of single metabolites and their related metabolic pathways revealed unexpected possible perturbations related to PD and underscored existing mechanisms that correlated with disease onset, stage, duration, motor score and pharmacological treatment. CONCLUSION: Metabolomics can be useful in pathogenetic studies and biomarker discovery. The latter needs large-scale validation and comparison with other neurodegenerative conditions.

Assessment of apathy minimising the effect of motor dysfunctions in Parkinson's disease: a validation study of the dimensional apathy scale.

PURPOSE: Apathy is associated with motor symptoms in Parkinson's disease (PD); therefore, its evaluation could be influenced by motor disability. The Dimensional Apathy Scale (DAS) evaluates apathy excluding confounding effects of motor symptoms. The present study had three major aims: (a) to explore the psychometric properties of the DAS in non-demented PD patients; (b) to determine an optimal cut-off score of the DAS to identify apathetic PD patients; and (c) to determine a specific apathy profile in PD patients as compared to healthy controls (HC). METHODS: One hundred and seven PD patients and 100 HC completed the DAS. To explore convergent and divergent validity of the DAS in PD, patients underwent the Apathy Evaluation Scale and tools for assessing depressive symptoms, anxiety and cognition. Clinical aspects were recorded. Receiver operating characteristic curve analyses were carried out to estimate the optimal cut-off score to identify clinically significant apathy. RESULTS: The DAS scores showed high internal consistency and good evidence for convergent and discriminant validity. Maximum discrimination between apathetic and non-apathetic patients was obtained with a cut-off score of 28.5 (total score range: 0-72 with higher score indicating more severe apathy). Comparison between PD and HC groups revealed significant differences on total DAS, behavioural/cognitive initiation and emotional subscales. CONCLUSIONS: The DAS is a valid and reliable tool to assess multidimensional apathy in PD, independently of severity of motor symptoms. Reduced initiation of thought and behaviour and emotional blunting characterised PD patients, without confounding effects of motor disability.

Serum uric acid is associated with apathy in early, drug-naïve Parkinson's disease.

Both low serum uric acid (UA) levels and apathy are considered biomarkers of cognitive decline and dementia in Parkinson's disease (PD). There is an urgent need to combine different biomarkers to predict disease course in PD. Data on the relationship between serum UA levels and apathy in PD are lacking. The aim of this study is to evaluate the relationship between serum UA levels and pure apathy in early, drug-naïve PD patients. Forty-nine early, drug-naïve PD patients were enrolled and stratified into two groups using the median serum UA levels at diagnosis (Group 1 serum UA ≤ 4.8 mg/dl; Group 2 serum UA > 4.8 mg/dl). The cohort was followed for the first 2 years of disease. Apathy was evaluated with the Apathy Evaluation Scale (AES). Patients with lower serum UA levels presented significant higher AES score compared to patients with higher serum UA levels. Regression analysis showed that baseline serum UA levels were significant determinants of AES scores at both baseline and 2-year follow up, irrespective of gender, age, attention/executive functions and dopamine replacement therapy when applicable. This is the first study showing a link between serum UA levels and apathy in non-demented, non-depressed, early, drug-naïve PD, being lower serum UA levels associated with greater apathy. Further follow up of our patients and replication of this observation in independent cohorts are needed to establish if this combination of biomarkers may help in characterizing a subgroup of PD patients at diagnosis.

Nonmotor predictors for levodopa requirement in de novo patients with Parkinson's disease.

The variability in the clinical phenotype of Parkinson's disease (PD) suggests the existence of several subtypes of the disease. Motor heterogeneity of PD is well established, but not nonmotor heterogeneity. At present, we are unable to predict the rate of progression of PD based on robust biomarkers. We aimed to examine the heterogeneity of PD by attempting to identify nonmotor factors associated with the rate of motor progression and functional decline, as measured by the time to reach the need for levodopa therapy during the first 4 years from diagnosis in a cohort of de novo PD patients. The median time to introduction of L-dopa for patients with urinary symptoms was significantly shorter than that for those without (20 vs. 37 months; P = 0.001). Cox's regression models showed that the urinary domain was associated with a higher probability of starting L-dopa (hazard ratio: 2.1; P = 0.002). There was no influence of such confounders as sex, age, baseline motor features, use of dopamine agonists and/or monoamine oxidase B inhibitors, and total L-dopa equivalent daily dosage. Patients with urinary symptoms had higher baseline and follow-up motor and nonmotor disturbances than those without. Our study suggests the existence of a subgroup of patients who show urinary symptoms along with an overall higher motor and nonmotor burden. Such patients are prone to manifest a rapid functional decline over the first 4 years of the disease. Urinary symptoms might be a clinical marker of severity as well as a possible nonmotor subtype of PD.

Do subjective memory complaints herald the onset of mild cognitive impairment in Parkinson disease?

BACKGROUND: Longitudinal studies on healthy participants have shown that subjective memory impairment (defined as subjective cognitive complaints with normal cognitive objective performance) might be a strong predictor of mild cognitive impairment (MCI). Parkinson disease (PD) also manifests cognitive disturbances, but whether subjective memory complaints may predict the development of MCI in PD has not yet been explored. METHODS: We prospectively screened newly diagnosed, untreated patients with PD in order to evaluate whether subjective memory complaints may predict development of MCI over a 2-year follow-up evaluation. RESULTS: We enrolled 76 de novo untreated patients with PD. Of the 76 patients, 23 (30.3%) complained memory issues. Among the patients cognitively unimpaired at baseline, those with subjective complaints were more likely to develop MCI at follow-up. The regression model confirmed that presence of subjective memory complaints at baseline was an independent predictor of development of MCI at follow-up. DISCUSSION: This is the first prospective study to explore the relationship between subjective and objective cognitive deficits in newly diagnosed, untreated patients. Our results provide preliminary evidence that subjective memory complaints might predict future development of MCI.

Non-motor symptoms in early Parkinson's disease: a 2-year follow-up study on previously untreated patients.

BACKGROUND: Non-motor symptoms are very common among patients with Parkinson's disease since the earliest stage, but little is known about their progression and their relationship with dopaminergic replacement therapy. METHODS: We studied non-motor symptoms before and after 2 years from dopaminergic therapy introduction in ninety-one newly diagnosed previously untreated PD patients. RESULTS: At baseline, nearly all patients (97.8%) referred at least one non-motor symptom. At follow-up, only few non-motor symptoms significantly changed. Particularly, depression and concentration became less frequent, while weight change significantly increased after introduction of dopamine agonists. CONCLUSIONS: We reported for the first time a 2-year prospective study on non-motor symptoms before and after starting therapy in newly diagnosed PD patients. Even if non-motor symptoms are very frequent in early stage, they tend to remain stable during the early phase of disease, being only few non-motor symptoms affected from dopaminergic therapy and, specifically, by the use of dopamine agonists.

Hearing impairment in Parkinson's disease: expanding the nonmotor phenotype.

The objective of this study was to evaluate hearing impairment in patients affected by Parkinson's disease compared with hearing scores observed in normal age- and sex-matched controls. One hundred eighteen consecutive patients with a clinical diagnosis of Parkinson's disease were screened. Severity of motor symptoms and staging were measured with the Unified Parkinson's Disease Rating Scale (section III) and the Hoehn and Yahr scale. Audiometric evaluation consisted of a comprehensive audiologic case history and questionnaire, visual otoscopic examination, acoustic immittance measures (tympanogram and acoustic reflexes), pure tone audiometry, and measurement of brain stem auditory-evoked potentials. Healthy age- and sex-matched subjects were selected as the control group. One hundred six of 118 patients were enrolled. Pure tone audiometry revealed age-dependent high-frequency hearing loss in patients with Parkinson's disease compared with both normative values and values for healthy age- and sex-matched controls (75/106 [71%], χ(2) = 5.959, P = .02; 92/106 [86.8%] vs 60/106 [56.6%], χ(2) = 23.804, P < .001, respectively). Pure tone audiometry scores correlated with Hoehn and Yahr scale scores (P < .05). Brain stem auditory-evoked potentials were normal in all patients. Our patients with Parkinson's disease showed age-dependent peripheral, unilateral, or bilateral hearing impairment. Whether these auditory deficits are intrinsic to Parkinson's disease or secondary to a more complex impaired processing of sensorial inputs occurring over the course of illness remains to be determined. Because α-synuclein is located predominately in the efferent neuronal system within the inner ear, it could affect susceptibility to noise-induced hearing loss or presbycusis. It is feasible that the natural aging process combined with neurodegenerative changes intrinsic to Parkinson's disease might interfere with cochlear transduction mechanisms, thus anticipating presbycusis.

Humoral efficacy of the third SARS-CoV-2 vaccine dose in Multiple Sclerosis subjects undergoing different disease-modifying therapies.

BACKGROUND: It remains unclear how vaccine doses and combinations of vaccination and infection affect the magnitude and quality of immune responses, particularly against novel SARS-CoV-2 variants in subjects with immune-related disorders, such as people with multiple sclerosis (pwMS). Several studies have evaluated the duration of anti-SARS-CoV-2 immune protection in healthy individuals; however clinical data suggest an attenuated short-term humoral response to SARS-CoV-2 vaccines in pwMS receiving disease-modifying therapies (DMTs). METHODS: In this prospective study, we evaluated the humoral response to the third (3rd) BNT162b2 vaccine (booster) dose in a monocentric cohort of pwMS undergoing eight different DMTs, all without previous SARS-CoV-2 infection. Quantitative determination of SARS-CoV-2 IgG Spike titre was carried out by anti-SARS-CoV-2 S assay in 65 pwMS and 9 healthy controls, all without previous SARS-CoV-2 infection. Moreover, these measurements were also compared to their relative levels at 21 days (T1) and ∼6 months (T2) after the second (2nd) vaccination. RESULTS: We observed that the humoral response to the booster dose in Interferon ß-1a-, Dimethyl fumarate- and Teriflunomide-treated pwMS is comparable to healthy controls, while increased in Cladribine-treated pwMS. Additionally, the 3rd dose elicits a seroconversion in the 100% of pwMS under Fingolimod and in the 65% of those under Ocrelizumab. Moreover, multivariate regression analysis showed that treatment with Interferon ß-1a, Dimethyl fumarate and Cladribine positively associates with an increased humoral response. CONCLUSIONS: Taken together this evidence strongly indicates the importance of the booster dose to enhance SARS-CoV-2-specific immunity especially in immunocompromised subjects, such as pwMS under DMTs.

Interferon Beta-1a treatment promotes SARS-CoV-2 mRNA vaccine response in multiple sclerosis subjects.

BACKGROUND: Several concerns exist on the immunogenicity of SARS-CoV-2 vaccines in multiple sclerosis (MS) subjects due to their immunomodulating disease modifying therapies (DMTs). Here we report a comparison of the humoral response to BNT162b2-mRNA coronavirus (COVID)-19 vaccine and the immunological phenotype in a cohort of 125 MS subjects undergoing different DMTs, with no history of SARS-CoV-2 infection. METHODS: We collected serum and blood samples at the first day of vaccine (T0) and 21 days after the second vaccine dose (T1) from 125 MS subjects, undergoing eight different DMTs. Sera were tested using the Elecsys anti-SARS-CoV-2-IgG assay for the detection of IgG antibodies to SARS-CoV-2 spike protein. The anti-spike IgG titres from MS subjects were compared with 24 age- and sex-matched healthy controls (HC). Percentage and absolute number of B and T lymphocytes were evaluated by cytofluorimetric analysis in the same study cohort. RESULTS: When compared with SARS-CoV-2 IgG levels in HC (n = 24, median 1089 (IQR 652.5-1625) U/mL), we observed an increased secretion of SARS-CoV-2 IgG in interferon-beta 1a (IFN)-treated MS subjects (n = 22, median 1916 (IQR 1024-2879) U/mL) and an impaired humoral response in MS subjects undergoing cladribine (CLAD) (n = 10, median 396.9 (IQR 37.52-790.9) U/mL), fingolimod (FTY) (n = 19, median 7.9 (IQR 4.8-147.6) U/mL) and ocrelizumab (OCRE) (n = 15, median 0.67 (IQR 0.4-5.9) U/mL) treatment. Moreover, analysis of geometric mean titre ratio (GMTR) between different DMT's groups of MS subjects revealed that, when compared with IFN-treated MS subjects, intrinsic antibody production was impaired in teriflunomide (TERI)-, natalizumab (NAT)-, CLAD-, FTY- and OCRE-, while preserved in DMF- and GA-treated MS subjects. CONCLUSION: Humoral response to BNT162b2-mRNA-vaccine was increased in IFN-treated MS subjects while clearly blunted in those under CLAD, FTY and OCRE treatment. This suggests that the DMTs could have a key role in the protection from SARS-CoV-2 related disease and complication in MS subjects, underlying a novel aspect that should be considered in the selection of the most appropriate therapy under COVID-19 pandemic.

Vestibular impairment and adaptive postural imbalance in parkinsonian patients with lateral trunk flexion.

Lateral trunk flexion is a very common clinical observation in patients affected by Parkinson's disease. Postural control is known to depend on vestibular, visual, and somatosensory information. The aim of this study was to investigate whether impairment of vestibular function can account for the postural alterations observed in parkinsonian patients with lateral trunk flexion. We evaluated vestibular function in 11 parkinsonian patients with lateral trunk flexion and in 11 age-, sex-, and disease duration-matched patients without lateral trunk flexion. The following vestibular tests were performed: infrared videonystagmography including fast and slow ocular movements, spontaneous-positional and evoked nystagmus search with and without visual fixation, fast positioning maneuvers, the bithermal caloric test, and the vibration test. A peripheral, unilateral vestibular hypofunction was identified in all patients with lateral trunk flexion. The vestibular hypofunction was ipsilateral to the leaning side and contralateral to the most affected parkinsonian side in all patients. In the control group, 7 subjects had no vestibular signs; 4 subjects had unilateral vestibular hypofunction without clinically evident lateral trunk flexion. Two of the latter patients subsequently developed lateral trunk flexion ipsilateral to the vestibular deficit and contralateral to the side most affected by Parkinson's disease. The processing of vestibular information was impaired in parkinsonian patients affected by lateral trunk flexion. The impairment was at least in part responsible for the patients' postural abnormality. We propose that the acronym PISA (Postural Imbalance Syndrome with vestibular Alterations) be used to describe the specific postural change observed in parkinsonian patients affected by a vestibular defect and lateral trunk flexion.

Progression of striatal and extrastriatal degeneration in multiple system atrophy: a longitudinal diffusion-weighted MR study.

Diffusion-weighted imaging has been largely used to detect and quantify early degenerative changes in patients with multiple system atrophy, but progression of neurodegeneration has been poorly investigated. We performed a serial diffusion-weighted imaging study in a population of multiple system atrophy patients and analyzed the evolution of diffusion properties in striatal and extrastriatal brain regions. Diffusion-weighted imaging was obtained in 11 multiple system atrophy patients at baseline and after a follow-up of 11.7 ± 1.2 months, and Trace (D) changes in different brain regions were correlated with disease duration and severity. A significant increase in Trace (D) was observed at follow-up in the putamen (P < .001), pons (P = .003), cerebellar white matter (P = .03), thalamus (P = .013), and frontal white matter (P = .021). Both Unified Multiple System Atrophy Rating Scale Part II and Unified Parkinson's Disease Rating Scale Part III scores significantly increased at follow-up (P = .003), but percent changes of Unified Parkinson's Disease Rating Scale Part III and Unified Multiple System Atrophy Rating Scale Part II did not correlate with percent changes of Trace (D) values in any brain region. This longitudinal study provides new insights into the progression of neurodegeneration in different brain regions in multiple system atrophy. Our results confirm that abnormal diffusivity in the putamen is sensitive to change over time in multiple system atrophy patients and show for the first time a progression of Trace (D) alterations in specific extrastriatal regions. Diffusivity changes in these regions may be useful for monitoring disease progression even after a short follow-up period. © 2011 Movement Disorder Society.

The "eye of the tiger" sign in pure akinesia with gait freezing.

The "eye of the tiger" is a neuroradiologic sign due to iron deposition in the globus pallidus: it appears as diffuse low signal intensity with a central area of high signal intensity confined to the globus pallidus. The "eye of the tiger" sign has been associated with neurodegeneration with brain iron accumulation type 1 (NBIA1), a condition caused by mutations in the gene encoding pantothenate kinase 2 (PANK2). However, the specificity of this neuroradiologic sign has been already challenged and it has been described in other neurodegenerative diseases. Here, we report the first case of a patient suffering from pure akinesia with gait freezing with the "eye of the tiger" sign in T2-weighted MRI sequences. All clinical, laboratory and radiologic data excluded other diagnosis and genetic testing excluded PANK2 mutations suggesting that the "eye of the tiger" is not specific for NBIA1 and may also occur in other movement disorders.

Multiple system atrophy is associated with changes in peripheral insulin-like growth factor system.

Insulin-like growth factors (IGF-I and IGF-II) have been shown to have several neurotrophic actions and IGF system may be impaired in neurodegenerative disorders. The aim of this study was to investigate the IGF system in patients with MSA and to evaluate correlations between this endocrine system and clinical features of the disease. Serum levels of IGF-I, IGF-II, insulin, IGF-binding protein 1 (BP1), and IGF-binding protein 3 (BP3) were measured in 25 patients with probable MSA and 25 age, sex and BMI-matched healthy controls. Clinical status of each patient was evaluated with the Unified Multiple System Atrophy Rating Scale (UMSARS) Part II and the Hoehn and Yahr rating scale. IGF-I levels were significantly higher in MSA (164.1 + 66.2 µg/L) than in healthy controls (111.7 + 60.3 µg/L; p = 0.001). Insulin levels were significantly higher in MSA patients (21.9 ± 14.4 µU/mL) than in healthy controls (13.3 ± 5.1 µU/mL, p = 0.048). No significant difference was found in serum IGF-II, IGF-BP1, and IGF- BP3 levels between patients with MSA and healthy controls. There was a trend toward significantly higher IGF-II levels in MSA patients with UMSARS score <26 (1026.3 ± 442.6 µg/L) than MSA patients with UMSARS score >26 (796.1 ± 234 µg/L, p = 0.055). The results of this study demonstrated that IGF system is altered in MSA. The degenerative process in MSA could lead to a compensatory increase in IGF-I and insulin in an attempt to provide additional support to degenerating neurons.

Costs of Parkinson's disease and antiparkinsonian pharmacotherapy: an Italian cohort study.

OBJECTIVE: Antiparkinsonian pharmacotherapy is costly and the determinants of drug costs in Parkinson's disease (PD) have been poorly investigated. The objective of this study was to investigate the costs of PD and antiparkinsonian drugs in an Italian cohort of patients and identify cost-driving factors of drug therapy. METHODS: Seventy outpatients with idiopathic PD were recruited in the Department of Neurology, Napoli University, Italy. Data on resource utilization were collected for 6 months using a bottom-up approach. Clinical status was evaluated using the Unified Parkinson's Disease Rating Scale. Direct and indirect costs were calculated from the societal perspective (figures of year 2009). Independent determinants of total costs and costs of antiparkinsonian drugs were identified using multivariate regression analysis. RESULTS: The total costs of PD were EUR 8,640 (95% CI: EUR 6,700-11,240) per patient over a 6-month period. Direct costs accounted for 70% of the total costs. Antiparkinsonian drugs (EUR 1,450; 95% CI: EUR 1,220-1,760) were the primary component of costs paid by the health insurance (39.6%) and one of the most expensive components of the direct costs (24.0%). The highest copayments made by patients were for antiparkinsonian drugs and medical equipment (58%). Independent determinants of the increased costs of antiparkinsonian pharmacotherapy were younger age and occurrence of motor fluctuations. CONCLUSIONS: Antiparkinsonian pharmacotherapy is one of the major cost components of PD-related costs for health insurance. It imposes a considerable economic burden on patients and their families as well.

Diffusion-weighted imaging in multiple system atrophy: a comparison between clinical subtypes.

Multiple system atrophy can be classified into two main types, a Parkinsonian (MSA-P) and a cerebellar (MSA-C) variant based on clinical presentation. We obtained diffusion-weighted magnetic resonance imaging (DWI) in 9 MSA-P and 12 MSA-C patients and 11 controls, and correlated DWI changes with disease duration and severity. We found that Trace (D) values in the entire and anterior putamen were significantly higher in MSA-P than in MSA-C patients and controls, whereas Trace (D) values in the cerebellum and middle cerebellar peduncle (MCP) were significantly higher in MSA-C than in MSA-P patients and controls. Increased disease duration was significantly correlated with increased Trace (D) values in pons of MSA-P patients, and in cerebellum and MCP of MSA-C patients. Both UMSARS and UPDRS motor scores positively correlated with entire and posterior putaminal Trace (D) values in MSA-P patients. The diffusivity changes parallel phenotypical and pathologic differences between MSA-P and MSA-C patients, suggesting that DWI is a feasible tool for in vivo evaluation of neurodegeneration in MSA. Based on our findings, Trace (D) measurements in the putamen and pons in MSA-P patients and in the cerebellum and MCP in MSA-C patients could serve as quantitative markers for microstructural damage in the course of disease.

Freezing of gait and executive functions in patients with Parkinson's disease.

Freezing of gait (FOG) is a frequent, disabling symptom of Parkinson's disease (PD). FOG usually lasts a few seconds. It refers to brief paroxysmal events during which a subject is unable to start or continue locomotion. Despite its frequency, FOG pathophysiology is unclear. Because a frontal lobe dysfunction or a disconnection between the frontal lobe and basal ganglia has been implicated in FOG, we explored frontal functions in PD patients using neuropsychological tests. Thirteen early-stage PD patients [Hoehn & Yahr score (H&Y) < or = 2.5] with freezing during "on " state (FOG+), and 15 age-, H&Y score-, and disease-duration-matched PD patients without freezing (FOG-) were investigated. No patient was demented or depressed. Assessment included the Unified Parkinson's Disease Rating Scale (UPDRS), FOG questionnaire, Mini Mental State Examination (MMSE), frontal assessment battery (FAB), phonemic verbal fluency, Stroop test (parts II and III), and ten-point clock test (TPCT). UPDRS and MMSE scores did not differ between the two groups. FAB, verbal fluency, and TPCT scores were significantly lower in FOG+ patients than in FOG- patients (FAB: P = 0.008; phonemic verbal fluency: P = 0.011; TPCT: P = 0.024). FOG correlated with lower scores at frontal tests in patients with early-stage PD.

The arginine growth hormone stimulation test in bradykinetic-rigid parkinsonisms.

The arginine growth hormone (GH) stimulation test differentiates the Parkinsonian variant of multiple system atrophy (MSA-P) from idiopathic Parkinson's disease (PD). Our aim was to evaluate the accuracy of the arginine GH stimulation test in distinguishing between PSP, MSA-P, and PD. We measured the GH response to arginine in serum samples of 26 MSA-P, 23 PSP, and 26 PD patients, and in 80 healthy controls. We used ANOVA followed by the Bonferroni test to compare GH values and peaks among groups. We used receiver operating characteristic curve analysis to establish the arginine cut-off level that best differentiated between MSA-P, PSP, and PD. The GH peak was significantly lower (P < 0.01) in MSA-P (1.46 +/- 0.29 microg/L) than in both PD (8.74 +/- 0.98 microg/L) and PSP (6.64 +/- 0.82 microg/L) patients, and controls (8.59 +/- 0.44 microg/L). Growth hormone peaked later in PSP patients than in PD patients and controls. At a cut-off level of 4 microg/L, arginine test distinguished MSA-P from PD with a sensitivity of 92% and a specificity of 96%, and MSA-P from PSP with a sensitivity of 78% and a specificity of 96%. The GH response to arginine differentiates MSA-P from PD and PSP with a good diagnostic accuracy. The neuroendocrine response to arginine of PSP patients differed from that of MSA-P patients, but was not identical to that of normal controls and PD patients. Our results suggest that the impairment of the central mechanisms modulating GH release differs between PSP and MSA-P.

Interoceptive processing deficit: A behavioral marker for subtyping Parkinson's disease.

BACKGROUND: Non-motor symptoms in Parkinson's disease (PD), such as cognitive, emotional, autonomic and somatosensory alterations, are not ubiquitous but vary between the tremor dominant (TD) and postural instability/gait difficulty (PIGD) subtypes of the syndrome. Non-motor phenomena (e.g., anxiety, depression and apathy) have been related to representation of autonomic and somatosensory sensations (interoception), and recent findings suggest interoceptive deficits in PD. OBJECTIVES: To test whether interoceptive processing is differently affected in TD and PIGD phenotypes, by assessing both interoceptive accuracy and sensibility in PD patients with TD and PIGD subtypes, and in healthy controls. METHODS: Interoceptive accuracy was measured by the heartbeat perception task requiring participants to count their own heartbeats in a given time interval. A time-estimation, control task was also administered asking participants to count the seconds in a set period of time. Interoceptive sensibility was assessed by a questionnaire of subjective interoception. Finally, the patients underwent measures of anxiety, depression, apathy and anhedonia, and impulsive-compulsive disturbances. RESULTS: The main results showed reduced interoceptive accuracy and sensibility in TD patients relative to both PIGD patients and healthy controls. Reduced interoceptive accuracy of TD group was a reliable result since their performance on the time estimation control task was comparable to that of both PIGD patients and healthy controls. CONCLUSIONS: These findings demonstrate that the behavioural assessment of different aspects of interoceptive processing can provide with a further marker for subtyping patients with PD.