Quantitative assessment of transmural fibrosis profile in the human atrium: evidence for a three-dimensional arrhythmic substrate by slice-to-slice histology.

AIMS: Intramural fibrosis represents a crucial factor in the formation of a three-dimensional (3D) substrate for atrial fibrillation (AF). However, the transmural distribution of fibrosis and its relationship with atrial overload remain largely unknown. The aim of this study is to quantify the transmural profile of atrial fibrosis in patients with different degrees of atrial dilatation and arrhythmic profiles by a high-resolution 3D histology method. METHODS AND RESULTS: Serial microtome-cut tissue slices, sampling the entire atrial wall thickness at 5 µm spatial resolution, were obtained from right atrial appendage specimens in 23 cardiac surgery patients. Atrial slices were picrosirius red stained, imaged by polarized light microscopy, and analysed by a custom-made segmentation algorithm. In all patients, the intramural fibrosis content displayed a progressive decrease alongside tissue depth, passing from 68.6 ± 11.6% in the subepicardium to 10-13% in the subendocardium. Distinct transmural fibrotic profiles were observed in patients with atrial dilatation with respect to control patients, where the first showed a slower decrease of fibrosis along tissue depth (exponential decay constant: 171.2 ± 54.5 vs. 80.9 ± 24.4 µm, P < 0.005). Similar slow fibrotic profiles were observed in patients with AF (142.8 ± 41.7 µm). Subepicardial and midwall levels of fibrosis correlated with the degree of atrial dilatation (ρ = 0.72, P < 0.001), while no correlation was found in subendocardial layers. CONCLUSIONS: Quantification of fibrosis transmural profile at high resolution is feasible by slice-to-slice histology. Deeper penetration of fibrosis in subepicardial and midwall layers in dilated atria may concur to the formation of a 3D arrhythmic substrate.

Changes in the properties of pure cotton surgical gowns and drapes with clinical use and reprocessing.

The impact of repeated in-hospital reprocessing on 100% cotton fabric continues to be debated. We analyzed the properties of surgical gowns and drapes over 15 months of clinical use. The amount of linting fibers and the water absorption rate increased significantly, but microbial and blood penetration was preserved.

Human Blood Platelets Adsorption on Polymeric Materials for Liquid Biopsy.

Platelets are emerging as a promising source of blood biomarkers for several pathologies, including cancer. New automated techniques for easier manipulation of platelets in the context of lab-on-a-chips could be of great support for liquid biopsy. Here, several polymeric materials were investigated for their behavior in terms of adhesion and activation of human platelets. Polymeric materials were selected among the most used in microfabrication (PDMS, PMMA and COC) and commercial and home-made resins for 3D printing technology with the aim to identify the most suitable for the realization of microdevices for human platelets isolation and analysis. To visualize adherent platelets and their activation state scanning, electron microscopy was used, while confocal microscopy was used for evaluating platelets' features. In addition, atomic force microscopy was employed to further study platelets adherent to the polymeric materials. Polymers were divided in two main groups: the most prone to platelet adhesion and materials that cause few or no platelets to adhere. Therefore, different polymeric materials could be identified as suitable for the realization of microdevices aimed at capturing human platelets, while other materials could be employed for the fabrication of microdevices or parts of microdevices for the processing of platelets, without loss on surfaces during the process.

Counter-Acting Candida albicans-Staphylococcus aureus Mixed Biofilm on Titanium Implants Using Microbial Biosurfactants.

This study aimed to grow a fungal-bacterial mixed biofilm on medical-grade titanium and assess the ability of the biosurfactant R89 (R89BS) coating to inhibit biofilm formation. Coated titanium discs (TDs) were obtained by physical absorption of R89BS. Candida albicans-Staphylococcus aureus biofilm on TDs was grown in Yeast Nitrogen Base, supplemented with dextrose and fetal bovine serum, renewing growth medium every 24 h and incubating at 37 °C under agitation. The anti-biofilm activity was evaluated by quantifying total biomass, microbial metabolic activity and microbial viability at 24, 48, and 72 h on coated and uncoated TDs. Scanning electron microscopy was used to evaluate biofilm architecture. R89BS cytotoxicity on human primary osteoblasts was assayed on solutions at concentrations from 0 to 200 µg/mL and using eluates from coated TDs. Mixed biofilm was significantly inhibited by R89BS coating, with similar effects on biofilm biomass, cell metabolic activity and cell viability. A biofilm inhibition >90% was observed at 24 h. A lower but significant inhibition was still present at 48 h of incubation. Viability tests on primary osteoblasts showed no cytotoxicity of coated TDs. R89BS coating was effective in reducing C. albicans-S. aureus mixed biofilm on titanium surfaces and is a promising strategy to prevent dental implants microbial colonization.

Rhamnolipid coating reduces microbial biofilm formation on titanium implants: an in vitro study.

BACKGROUND: Peri-implant mucositis and peri-implantitis are biofilm-related diseases causing major concern in oral implantology, requiring complex anti-infective procedures or implant removal. Microbial biosurfactants emerged as new anti-biofilm agents for coating implantable devices preserving biocompatibility. This study aimed to assess the efficacy of rhamnolipid biosurfactant R89 (R89BS) to reduce Staphylococcus aureus and Staphylococcus epidermidis biofilm formation on titanium. METHODS: R89BS was physically adsorbed on titanium discs (TDs). Cytotoxicity of coated TDs was evaluated on normal lung fibroblasts (MRC5) using a lactate dehydrogenase assay. The ability of coated TDs to inhibit biofilm formation was evaluated by quantifying biofilm biomass and cell metabolic activity, at different time-points, with respect to uncoated controls. A qualitative analysis of sessile bacteria was also performed by scanning electron microscopy. RESULTS: R89BS-coated discs showed no cytotoxic effects. TDs coated with 4 mg/mL R89BS inhibited the biofilm biomass of S. aureus by 99%, 47% and 7% and of S. epidermidis by 54%, 29%, and 10% at 24, 48 and 72 h respectively. A significant reduction of the biofilm metabolic activity was also documented. The same coating applied on three commercial implant surfaces resulted in a biomass inhibition higher than 90% for S. aureus, and up to 78% for S. epidermidis at 24 h. CONCLUSIONS: R89BS-coating was effective in reducing Staphylococcus biofilm formation at the titanium implant surface. The anti-biofilm action can be obtained on several different commercially available implant surfaces, independently of their surface morphology.

Morphological MRI of knee cartilage: repeatability and reproducibility of damage evaluation and correlation with gross pathology examination.

OBJECTIVE: To assess the performance of a morphological evaluation, based on a clinically relevant magnetic resonance imaging (MRI) protocol, in scoring the severity of knee cartilage damage. Specifically, to evaluate the reproducibility, repeatability, and agreement of MRI evaluation with the gross pathology examination (GPE) of the tissue. METHODS: MRI of the knee was performed the day before surgery in 23 patients undergoing total knee arthroplasty. Osteochondral tissue resections were collected and chondral defects were scored by GPE according to a semi-quantitative scale. MR images were independently scored by four radiologists, who assessed the severity of chondral damage according to equivalent criteria. Inter- and intra-rater agreements of MRI evaluations were assessed. Correlation, precision, and accuracy metrics between MRI and GPE scores were calculated. RESULTS: Moderate to substantial inter-rater agreement in scoring cartilage damage by MRI was found among radiologists. Intra-rater agreement was higher than 96%. A significant positive monotonic correlation between GPE and MRI scores was observed for all radiologists, although higher correlation values were obtained by radiologists with expertise in musculoskeletal radiology and/or longer experience. The accuracy of MRI scores displayed a spatial pattern, characterized by lesion overestimation in the lateral condyle and underestimation in the medial condyle with respect to GPE. CONCLUSIONS: Evaluation of knee cartilage morphology by MRI is a reproducible and repeatable technique, which positively correlates with GPE. Clinical expertise in musculoskeletal radiology positively impacts the evaluation reliability. These findings may help to address limitations in MRI evaluation of knee chondral lesions, thus improving MRI assessment of knee cartilage. KEY POINTS: • MRI evaluation of knee cartilage shows moderate to strong correlation with gross pathology examination. • MRI evaluation overestimates cartilage damage in the lateral condyle and underestimates it in the medial condyle. • Education and experience of the radiologist play a role in MRI evaluation of knee chondral lesions.

Microscopic Observation of Proliferative Membranes in Fibrocontractive Retinal Disorders.

Proliferative membranes of fibrocontractive retinal disorders are extensively studied from the morphological and evolutive point of view. Despite this, little is known of their cellular composition. In this study, the authors investigated the morphological characteristics and cell composition of various types of surgically excised proliferative membranes and internal limiting membranes (ILMs), in order to provide new data supporting or challenging the pathogenic theories proposed until now. Sixty-nine specimens from 64 eyes of 64 consecutive patients were collected at surgery and subjected to a multilevel analysis by means of optical and electron microscopy. Membrane samples were semiquantitatively evaluated for the amount and distribution of cell nuclei and pigment. Immunohistochemical staining was performed with antibodies to alpha smooth muscle actin and CD68. Data were analyzed after grouping according to the following tissue types: ILM (20 specimens), epiretinal membrane (ERM) (22 specimens), ILM + ERM (20 specimens), and proliferative vitreoretinopathy (PVR) (7 specimens). The cell components found in the ERM specimens, like myofibroblasts, macrophages, and polymorphonuclear cells, were recognized as the expression of cell migration and differentiation that induced an inflammatory process and a fibroproliferative repair process. The detection of pigments in specific types of ERM, like those associated with lamellar macular hole (LMH) or secondary to retinal detachment (RD), diabetes, and PVR, suggested that retinal pigment epithelium (RPE) cells may have a role in the development of these vitreoretinal disorders. The reduction of the ERM cellularity with the patient's age supports the hypothesis that ERM evolves in time up to a fibrous tissue formation.

Dental Implants with Anti-Biofilm Properties: A Pilot Study for Developing a New Sericin-Based Coating.

AIM: several strategies have been tested in recent years to prevent bacterial colonization of dental implants. Sericin, one of the two main silk proteins, possesses relevant biological activities and also literature reports about its potential antibacterial properties, but results are discordant and not yet definitive. The aim of this study was to evaluate the effectiveness of different experimental protocols in order to obtain a sericin-based coating on medical grade titanium (Ti) able to reduce microbial adhesion to the dental implant surface. MATERIALS AND METHODS: different strategies for covalent bonding of sericin to Ti were pursued throughout a multi-step procedure on Ti-6Al-4V disks. The surface of grade 5 Ti was initially immersed in NaOH solution to obtain the exposure of functional -OH groups. Two different silanization strategies were then tested using aminopropyltriethoxysilane (APTES). Eventually, the bonding between silanized Ti-6Al-4V and sericin was obtained with two different crosslinking processes: glutaraldehyde (GLU) or carbodiimide/N-Hydroxy-succinimide (EDC/NHS). Micro-morphological and compositional analyses were performed on the samples at each intermediate step to assess the most effective coating strategy able to optimize the silanization and bioconjugation processes. Microbiological tests on the coated Ti-6Al-4V disks were conducted in vitro using a standard biofilm producer strain of Staphylococcus aureus (ATCC 6538) to quantify the inhibition of microbial biofilm formation (anti-biofilm efficacy) at 24 hours. RESULTS: both silanization techniques resulted in a significant increase of silicon (Si) on the Ti-6Al-4V surfaces etched with NaOH. Differences were found between GLU and EDC/NHS bioconjugation strategies in terms of composition, surface micro-morphology and anti-biofilm efficacy. Ti-6Al-4V samples coated with GLU-bound sericin after silanization obtained via vapor phase deposition proved that this technique is the most convenient and effective coating strategy, resulting in a bacterial inhibition of about 53% in respect to the uncoated Ti-6Al-4V disks. CONCLUSIONS: The coating with glutaraldehyde-bound sericin after silanization in the vapor phase showed promising bacterial inhibition values with a significant reduction of S. aureus biofilm. Further studies including higher number of replicates and more peri-implant-relevant microorganisms are needed to evaluate the applicability of this experimental protocol to dental implants.

Prostate calcifications: A case series supporting the microbial biofilm theory.

Purpose: Prostate calcifications are a common finding during transrectal prostate ultrasound in both healthy subjects and patients, but their etiopathogenesis and clinical significance are not fully understood. We aimed to establish a new methodology for evaluating the role of microbial biofilms in the genesis of prostate calcifications. Materials and Methods: Ten consecutive patients who had undergone radical prostatectomy were enrolled in this study. All of the patients presented with prostate calcifications during transrectal ultrasound evaluation before surgery and underwent Meares-Stamey tests and clinical evaluation with the National Institutes of Health Chronic Prostatitis Symptom Index and the International Prostate Symptom Score. At the time of radical prostatectomy, the prostate specimen, after removal, was analyzed with ultrasonography under sterile conditions in the operating room. Core biopsy specimens were taken from the site of prostate calcification and subjected to ultrastructural and microbiological analysis. Results: The results of the Meares-Stamey test showed only 1 of 10 patients (10%) with positive cultures for Escherichia coli. Two of five patients (40%) had positive cultures from prostate biopsy specimens. Enterococcus faecalis, Enterococcus raffinosus, and Citrobacter freundii were isolated. Ultrastructural analysis of the prostate biopsy specimens showed prostate calcifications in 6 of 10 patients (60%), and a structured microbial biofilm in 1 patient who had positive cultures for E. faecalis and E. raffinosus. Conclusions: Although the findings are supported by a low number of patients, this study highlights the validity of the proposed methodology for investigating the role of bacterial biofilms in the genesis of prostate calcification.

Early healing of peri-implant mucosa in man.

AIM: To analyse (i) cellular and vascular densities in the connective tissue interface portion of the peri-implant mucosa and (ii) tissue interactions with the titanium surface during early stages of healing. MATERIALS AND METHODS: Circumferential biopsies of peri-implant soft tissues were retrieved together with custom-made abutments at 27 implants in 21 patients after 2, 4, 6, 8 and 12 weeks of healing. Following fixation, the peri-implant soft tissue was separated from the abutments, divided into four units and embedded in paraffin. Sections were produced and prepared for immunohistochemical analysis. The abutments were examined by SEM. RESULTS: T and B cells occurred in clusters with a decreasing cell density from 4 to 8 weeks of healing in the connective tissue lateral of the abutment. Macrophages were evenly distributed in the connective tissue along the abutment/tissue interface, while polymorphonuclear (PMN) cells were confined to the tissue portion lateral to the junctional epithelium. Vascular structures showed a decrease in density from 2 to 8 weeks of healing. SEM analyses of the abutments revealed an increased presence of tissue remnants attached to the surface with increasing healing time. A biofilm was consistently observed in a supra-mucosal position, apical of which a "clear zone" occurred that separated the tissue remnants and the biofilm. CONCLUSION: Onset and resolution of inflammation together with increasing tissue attachment to the implant characterize healing of peri-implant mucosa.

A spectral approach for the quantitative description of cardiac collagen network from nonlinear optical imaging.

The assessment of collagen structure in cardiac pathology, such as atrial fibrillation (AF), is essential for a complete understanding of the disease. This paper introduces a novel methodology for the quantitative description of collagen network properties, based on the combination of nonlinear optical microscopy with a spectral approach of image processing and analysis. Second-harmonic generation (SHG) microscopy was applied to atrial tissue samples from cardiac surgery patients, providing label-free, selective visualization of the collagen structure. The spectral analysis framework, based on 2D-FFT, was applied to the SHG images, yielding a multiparametric description of collagen fiber orientation (angle and anisotropy indexes) and texture scale (dominant wavelength and peak dispersion indexes). The proof-of-concept application of the methodology showed the capability of our approach to detect and quantify differences in the structural properties of the collagen network in AF versus sinus rhythm patients. These results suggest the potential of our approach in the assessment of collagen properties in cardiac pathologies related to a fibrotic structural component.

A Multi-techniques Approach to assess reprocessing of Single-use electrosurgical pencils.

Reprocessing and reuse of single-use electrosurgical pencils (EPs) is a diffused practice in countries with limited access to healthcare subvention system and in developing countries. However, safety and efficacy issues are associated to this practice, requiring specific methods for checking the reprocessed device before clinical re-use. This study aimed at defining a set of testing methods for assessing thermal and surface characteristics of reprocessed single-use EPs and evaluating the suitability of these techniques for revealing modifications between brand new and reprocessed single-use EPs. We reported a multi-technique approach based on optical and electron microscopy, X-rays spectroscopy and thermal analysis. The assessment of a total of 30 variables of interest on both brand new and reprocessed devices, allowed to identify the most informative ones. Seven of the evaluated variables were found to differentiate the reprocessed device from the new ones in a significant way. The presented methods deserve potential for tracking modifications during the device lifecycle.

Solidago, orthosiphon, birch and cranberry extracts can decrease microbial colonization and biofilm development in indwelling urinary catheter: a microbiologic and ultrastructural pilot study.

PURPOSE: Plants extracts are used in urology to manage urinary tract infections. We aimed to evaluate the efficacy of a preparation with solidago, orthosiphon, birch and cranberry extracts (CISTIMEV PLUS(®)) in reducing microbial colonization and biofilm development in patients with indwelling urinary catheters. METHODS: All consecutive outpatients attending our department between January and June 2010 for the substitution of indwelling catheters were considered for this single-blinded, randomized and controlled pilot study to test superiority of the preventative management (CISTIMEV PLUS(®), 1 tablet daily for 30 days) in respect to no treatment. A sample size of 10-40 participants per group was considered adequate. All patients underwent urine culture the same day of the catheter substitution and were then randomized into test group (n = 48) and control group (n = 35). Ultrastructural analysis was also performed. After 30 days, the catheter was replaced and the analysis repeated. The primary outcome was the rate of positive urinary culture at the end of the entire study period. RESULTS: Ten patients abandoned the study. At 30 days, according to per-protocol analysis, the groups statistically differed regarding the rate of positive urine cultures: test group 10/43 and control group 16/30 (p = 0.013) (-30.1 % [95 % CI -51.94 to -8.21]). The most common isolated bacteria were Escherichia coli and Enterococcus faecalis. CONCLUSIONS: The use of solidago, orthosiphon, birch and cranberry extracts resulted in a significant reduction of microbial colonization in patients with indwelling urinary catheters. Larger clinical trials are needed to demonstrate that the effects here reported are sufficient to reduce symptomatic catheter-associated urinary tract infections.

Hemodialysis catheter thrombi: visualization and quantification of microstructures and cellular composition.

PURPOSE: Despite the increasing use of central venous catheters (CVC) for hemodialysis in clinical practice, the role of CVC in thrombus development is poorly understood. This work aims at defining new methods and protocols for assessing the micromorphology and composition of thrombi formed into tunneled and non-tunneled hemodialysis CVC removed from patients. 
 METHODS: Twenty-nine CVCs were collected and the microscopic features of intra-luminal thrombi were quantified by scanning electron microscopy (SEM) and visualized by two photon laser scanning microscopy (TPLSM). 
 RESULTS: SEM quantification showed that fibrin was the most abundant structure in CVC thrombi. Specifically, the median micromorphologic composition of the surface layer resulted in: 42.6% of fibrin plaque, 16.3% of fibrin network, 0.4% of fibrin fibers, 9.3% of platelets, 10.3% of erythrocytes and 1.7% of white blood cells. TPLSM showed that sub-surface layers were instead composed by smaller amounts of fibrin and platelets and higher amounts of blood cells.
 CONCLUSIONS: Integration of SEM and TPLSM was found to be an excellent tool for characterizing thrombi in hemodialysis CVC removed from patients. Protocols and techniques presented here may be useful in the development and testing of new strategies for limiting thrombus formation on vascular access because of CVC.

Percutaneous endoscopic gastrostomy in amyotrophic lateral sclerosis: effect on survival.

BACKGROUND: Percutaneous endoscopic gastrostomy (PEG) is offered to amyotrophic lateral sclerosis (ALS) patients with severe dysphagia. Immediate benefits of PEG are adequate food intake and weight stabilization. However, the impact of PEG on survival is still uncertain. In this work we retrospectively evaluated the effect of PEG on survival in a cohort of ALS patients followed in a tertiary referral centre. METHODS: Between 2000 and 2007, 150 dysphagic ALS patients were followed until death or tracheostomy. PEG was placed in 76 patients who accepted the procedure and survival was analysed using the Kaplan-Meier life-table method. RESULTS: In ALS patients submitted to PEG, no major complications were observed. Total median survival time from symptom onset was 38 months for PEG users as compared to 32 months for the remaining dysphagic patients who declined the procedure (p=0.05). Among bulbar-onset patients, PEG users showed a median survival time longer than those with no PEG (28 months vs. 25 months), even though the difference was not significant. Conversely, dysphagic spinal-onset patients with PEG lived significantly longer than those who refused this palliative care (44 months vs. 36 months, p=0.046). Survival in patients with PEG was not affected by the severity of the respiratory impairment, as measured by forced vital capacity. CONCLUSIONS: This study demonstrates that PEG improves survival in dysphagic ALS patients, with few side effects. The procedure is safe and applicable even to patients with impaired respiratory function. PEG remains a milestone in palliative care in dysphagic ALS patients.

Restless legs syndrome in patients with amyotrophic lateral sclerosis.

We aimed to evaluate the frequency and determinants of restless legs syndrome (RLS) in a group of 76 patients with amyotrophic lateral sclerosis (ALS) and 100 control subjects. A diagnosis of RLS was made according to the criteria of the International RLS Study Group, and severity was assessed by the RLS severity scale. RLS was significantly more frequent in patients with ALS (ALS/RLS(+)) than in control subjects (25% vs. 8%; P = 0.002). Compared with control subjects, patients with ALS/RLS(+) showed shorter history of RLS complaints and higher frequency of symptoms occurrence. Moreover, compared with those without RLS, patients with ALS/RLS(+) showed increased functional impairment and more often reported sleep complaints. Multivariate logistic regression confirmed the association between RLS and functional impairment. Our findings suggest that RLS should be considered as a possible cause of disrupted sleep in patients with ALS and should be specifically investigated in these patients.

A cervical myelopathy with a Hirayama disease-like phenotype.

A 21-year-old man with a muscular atrophy of the left distal upper extremity is presented. The disorder had been progressive over a few years, showing an exacerbation of the hand's weakness when the patient worked in a chilled environment (i.e., in a cold room). The patient's diagnostic work-up was extensive and the MRI documented the presence of a cervical myelopathy, associated to an inversion of the physiological lordosis at the C5-C6 level, with a phenotype highly resembling Hirayama disease. This case indirectly supports the debated hypothesis that juvenile amyotrophy of the upper limb (Hirayama disease) is actually a type of cervical myelopathy, with a likely ischaemic pathogenesis of the ventral horns.

Expression and developmental regulation of the cystine/glutamate exchanger (xc-) in the rat.

The cystine/glutamate exchanger (antiporter x (c) (-) ) is a membrane transporter involved in the uptake of cystine, the rate-limiting amino acid in the synthesis of glutathione. Recent studies suggest that the antiporter plays a role in the slow oxidative excitotoxity and in the pathological effects of beta-N-oxalylamino-L: -alanine, the molecule responsible for neurolathyrism, a neurotoxic upper motor neuron disease. The mouse cystine/glutamate exchanger has been cloned and showed to be composed of two distinct proteins, one of which being a novel protein, named xCT, of 502 amino acids and 12 putative trans-membrane domains. We have generated and purified a polyclonal antibody to mouse xCT and studied its expression in rat brain and in different cultured cells (astrocytes, fibroblasts and neurons) using Western blot and immunocytochemical techniques. Expression of xCT was also studied in rat brain and muscle at different developmental stages. Parallel experiments were carried out with antibodies to the heavy chain of 4F2 surface antigen, the non-specific subunit of the antiporter x (c) (-) . xCT antibody detected in all cell and tissue extracts a specific band of about 40 kDa. Subcellular fractionation demonstrated that xCT is concentrated mainly in the microsomal-mitochondrial fraction, in accord with its structure as transmembrane protein. Immunocytochemical analysis showed a strong staining in all cells examined, included neurons. Furthermore, both xCT and the heavy chain of 4F2 surface antigen increased in the brain during development, reaching the highest expression in adulthood. The study of the expression and developmental profile of xCT represents a first step towards a better characterization of its biochemical properties and function, which in turn may help to understand the relative contribution of the x (c) (-) antiporter in the pathogenesis of certain neurodegenerative diseases.

Acute reversible parkinsonism in a diabetic-uremic patient.

Acute movement disorders with basal ganglia lesions have been recently described in diabetic-uremic patients of Asian descent. The process is often reversible, with a favourable clinical outcome. Metabolic (i.e. uremic toxins) and microangiopathic changes have been suggested to be involved in its pathophysiology, even though racial and/or genetic factors might play a role too. In this report, we present a Caucasian diabetic patient with a long-lasting mild uremia in which acute parkinsonism occurred after a steep and unexpected increase of the serum creatinine. The follow-up demonstrated a significant improvement of the neurological signs and symptoms, the creatinine level lowered close to the premorbid levels, and after several months the patient had fully recovered. Our case history suggests that this unusual clinical syndrome is most probably not restricted to Asian patients. Because its potentially favourable outcome, it should be regularly included in the differential diagnosis of acute movement disorders.

Development of chronic hypoventilation in amyotrophic lateral sclerosis patients.

Early prediction of respiratory muscle involvement and chronic hypoventilation (CH) in amyotrophic lateral sclerosis (ALS) patients can help to plan mechanical ventilatory aids and palliative care interventions well before respiratory failure occurs. To describe the natural history of the progressive pulmonary dysfunction leading to CH, and to identify potential parameters associated with its development in ALS, we prospectively followed 38 ALS patients up to 26 months, starting from their first presentation at our Clinic. At study entry, median FVC was 87% (interquartile range: 72-104%) and declined by 10% after 6 months (range: 2-49%), showing a very high inter-patient variability. Over the 26-months follow-up, 19 patients (50%) presented CH in the first 12 months, and eight patients (21%) developed CH in the remaining 14 months of the study. The remaining 29% of patients did not show signs of CH during the whole period of observation. In the Cox model, the category of disease progression (rapid vs. intermediate and slow), assessed using the Appel ALS Rating Scale (AARS) in the first 3 months after presentation, was the only variable associated with a significantly increased likelihood of CH. We conclude that CH can occur within 1 year from presentation in a great proportion of patients, independently from their initial respiratory status. Including the patients in specific categories of early disease progression, as assessed with the AARS, could be a sensitive method to identify patients with different risk of developing CH, and may help physicians to more efficiently plan the frequencies of respiratory evaluations, initiate mechanical ventilation and discuss advance directives with the patients and their caregivers.