Effect of Levodopa Initiation on the Gut Microbiota in Parkinson's Disease.

Background: The impact of Levodopa on the gut microbiota of Parkinson's disease (PD) patients has not been sufficiently addressed. Methods: We conducted a longitudinal study to examine the impact of Levodopa initiation on the gut microbiota composition of 19 PD patients who had not previously been exposed to Levodopa. Patients provided two stool samples prior to and two samples 90 days after starting Levodopa. Motor impairment (MDS-UPDRS Part III), diet, and other patient characteristics were assessed. 16S rRNA gene amplicon sequencing was used to characterize the microbiota. We examined, cross-sectionally and longitudinally, the associations between Levodopa use and alpha and beta diversity and performed feature-wise, multivariate modeling to identify taxa associated longitudinally with Levodopa use and with improvement in motor function after Levodopa administration. Results: We did not observe significant differences in alpha or beta diversity before vs. after initiation of Levodopa. In longitudinal feature-wise analyses, at the genus level, no taxa were significantly associated with Levodopa use after false discovery rate (FDR) correction (q < 0.05). We observed a marginally lower relative abundance of bacteria belonging to Clostridium group IV in PD patients who experienced a medium or large improvement in motor impairment in response to Levodopa compared to those with a small response [ß = -0.64 (SE: 0.18), p-trend: 0.00015 p-FDR: 0.019]. Conclusions: In this study, Levodopa was not associated with changes in microbiota composition in this longitudinal analysis. The association between abundance of Clostridium group IV and short-term motor symptom response to Levodopa is preliminary and should be investigated in larger, longer-term studies, that include a control group.

Association of Dexamethasone with Shunt Requirement, Early Disability, and Medical Complications in Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND AND PURPOSE: Current guidelines do not support the routine use of corticosteroids in patients with aneurysmal subarachnoid hemorrhage (aSAH). However, corticosteroids use in aSAH has been practiced at some centers by convention. The aim of the study was to determine the incidence of hydrocephalus requiring ventriculoperitoneal shunt (VPS) placement as well as functional outcome on discharge and adverse events attributed to corticosteroids in patients with aSAH treated with different dexamethasone (DXM) treatment schemes. METHODS: We retrospectively analyzed 206 patients with aSAH stratified to three groups based on the DXM treatment scheme: no corticosteroids, short course of DXM (S-DXM; 4 mg every 6 h for 1 day followed by a daily total dose reduction by 25% and then by 50% on last day), and long course of DXM (L-DXM; 4 mg every 6 h for 5-7 days followed by reduction by 50% every other day). The primary outcome measure was the placement of a VPS, and the secondary outcome was a good functional outcome [modified Rankin Scale (mRS) 0-3] at hospital discharge. Safety measures were the incidence of infection (pneumonia, urinary tract infection, ventriculitis, meningitis), presence of delirium, and hyperglycemia. RESULTS: There was no difference in the rate of external ventricular drain (EVD) (p = 0.164) and VPS placement (p = 0.792), nor in the rate of good outcome (p = 0.928) among three defined treatment regimens. Moreover, the median duration of treatment with EVD did not differ between subjects treated with no corticosteroids, S-DXM, and L-DXM (p = 0.905), and the probability of EVD removal was similar when stratified according to treatment regimens (log-rank; p = 0.256). Patients who received L-DXM had significantly more complications as compared to patients, who received no corticosteroids or S-DXM (78.4% vs. 58.6%; p = 0.005). After adjustment, L-DXM remained independently associated with increased risk of combined adverse events (OR = 2.72; 95%CI, 1.30-5.72; p = 0.008), infection (OR = 3.45; 95%CI, 1.63-7.30; p = 0.001) and hyperglycemia (OR = 2.05; 95%CI, 1.04-4.04; p = 0.039). CONCLUSIONS: DXM use among patients with aSAH did not relate to the rate of EVD and VPS placement, duration of EVD treatment, and functional disability at discharge but increased the risk of medical complications.

Case of primary Sjogren's syndrome preceded by dystonia.

There are only six cases in literature that describe development of dystonia with Sjogren's syndrome (SS). We describe a case of a 43-year-old woman who presented with symptoms including movement disorder, sensory neurogenic bladder, sensory loss and neuropathic pain, migraine like headaches, musculoskeletal pain, Raynaud's phenomenon and dysautonomia. Symptoms started in 2000, with weakness that progressed to dystonia in 2003. Diagnostic work-up was inconclusive with negative inflammatory serologies, cerebrospinal fluid and MRI for many years. After patient developed sicca syndrome with dry eyes and mouth in 2009, her rheumatoid factor titre was elevated (550 IU/mL), erythrocyte sedimentation rate, anti-Sjogrens syndrome-related antigen A (anti-Ro/SSA) and anti-SSB/La: anti-Sjogrens syndrome-related antigen B (anti-La/SSB) became positive. Lip biopsy confirmed diagnosis of SS. She was diagnosed with primary SS with neurological involvement. Her symptoms responded well to intravenous methylprednisolone. Symptoms stabilised with trials of immune-suppressive therapy. This is a case that demonstrates the delay of diagnosing SS with preceding unique neurological association.

Nitric Oxide and Mitochondrial Function in Neurological Diseases.

Mitochondria are key cellular organelles that play crucial roles in the energy production and regulation of cellular metabolism. Accumulating evidence suggests that mitochondrial activity can be modulated by nitric oxide (NO). As a key neurotransmitter in biologic systems, NO mediates the majority of its function through activation of the cyclic guanylyl cyclase (cGC) signaling pathway and S-nitrosylation of a variety of proteins involved in cellular functioning including those involved in mitochondrial biology. Moreover, excess NO or the formation of reactive NO species (RNS), e.g., peroxynitrite (ONOO-), impairs mitochondrial functioning and this, in conjunction with nuclear events, eventually affects neuronal cell metabolism and survival, contributing to the pathogenesis of several neurodegenerative diseases. In this review we highlight the possible mechanisms underlying the noxious effects of excess NO and RNS on mitochondrial function including (i) negative effects on electron transport chain (ETC); (ii) ONOO--mediated alteration in mitochondrial permeability transition; (iii) enhanced mitochondrial fragmentation and autophagy through S-nitrosylation of key proteins involved in this process such as dynamin-related protein 1 (DRP-1) and Parkin/PINK1 (protein phosphatase and tensin homolog-induced kinase 1) complex; (iv) alterations in the mitochondrial metabolic pathways including Krebs cycle, glycolysis, fatty acid metabolism, and urea cycle; and finally (v) mitochondrial ONOO--induced nuclear toxicity and subsequent release of apoptosis-inducing factor (AIF) from mitochondria, causing neuronal cell death. These proposed mechanisms highlight the multidimensional nature of NO and its signaling in the mitochondrial function. Understanding the mechanisms by which NO mediates mitochondrial (dys)function can provide new insights into the treatment of neurodegenerative diseases.