Disruption of the microbiota-gut-brain axis is a defining characteristic of the α-Gal A (-/0) mouse model of Fabry disease.

Fabry disease (FD) is an X-linked metabolic disease caused by a deficiency in α-galactosidase A (α-Gal A) activity. This causes accumulation of glycosphingolipids, especially globotriaosylceramide (Gb3), in different cells and organs. Neuropathic pain and gastrointestinal (GI) symptoms, such as abdominal pain, nausea, diarrhea, constipation, and early satiety, are the most frequent symptoms reported by FD patients and severely affect their quality of life. It is generally accepted that Gb3 and lyso-Gb3 are involved in the symptoms; nevertheless, the origin of these symptoms is complex and multifactorial, and the exact mechanisms of pathogenesis are still poorly understood. Here, we used a murine model of FD, the male α-Gal A (-/0) mouse, to characterize functionality, behavior, and microbiota in an attempt to elucidate the microbiota-gut-brain axis at three different ages. We provided evidence of a diarrhea-like phenotype and visceral hypersensitivity in our FD model together with reduced locomotor activity and anxiety-like behavior. We also showed for the first time that symptomology was associated with early compositional and functional dysbiosis of the gut microbiota, paralleled by alterations in fecal short-chain fatty acid levels, which partly persisted with advancing age. Interestingly, most of the dysbiotic features suggested a disruption of gut homeostasis, possibly contributing to accelerated intestinal transit, visceral hypersensitivity, and impaired communication along the gut-brain axis.

Estimating motor unit numbers from a CMAP scan: Repeatability study on three muscles at 15 centres.

OBJECTIVE: To assess the repeatability and suitability for multicentre studies of MScanFit motor unit number estimation (MUNE), which involves modelling compound muscle action potential (CMAP) scans. METHODS: Fifteen groups in 9 countries recorded CMAP scans twice, 1-2 weeks apart in healthy subjects from abductor pollicis brevis (APB), abductor digiti minimi (ADM) and tibialis anterior (TA) muscles. The original MScanFit program (MScanFit-1) was compared with a revised version (MScanFit-2), designed to accommodate different muscles and recording conditions by setting the minimal motor unit size as a function of maximum CMAP. RESULTS: Complete sets of 6 recordings were obtained from 148 subjects. CMAP amplitudes differed significantly between centres for all muscles, and the same was true for MScanFit-1 MUNE. With MScanFit-2, MUNE differed less between centres but remained significantly different for APB. Coefficients of variation between repeats were 18.0% for ADM, 16.8% for APB, and 12.1% for TA. CONCLUSIONS: It is recommended for multicentre studies to use MScanFit-2 for analysis. TA provided the least variable MUNE values between subjects and the most repeatable within subjects. SIGNIFICANCE: MScanFit was primarily devised to model the discontinuities in CMAP scans in patients and is less suitable for healthy subjects with smooth scans.

A comparative blind study between skin biopsy and seed amplification assay to disclose pathological α-synuclein in RBD.

To compare the diagnostic accuracy of the immunofluorescence (IF) technique and aSyn-seed amplification assay (aSyn-SAA) of skin and cerebrospinal fluid (CSF) in disclosing pathological α-syn in idiopathic idiopathic REM sleep behavior disorder (iRBD) as early phase of a synucleinopathy. We prospectively recruited 41 patients with iRBD and 40 matched clinical controls including RBD associated with type 1 Narcolepsy (RBD-NT1, 21 patients), iatrogenic causes (2 pt) or OSAS (6 pt) and 11 patients with peripheral neuropathies. IF from samples taken by skin biopsy and aSyn-SAA from skin and CSF samples were analysed blinded to the clinical diagnosis. IF showed a good diagnostic accuracy (89%) that was lower in the case of skin and CSF-based aSyn-SAA (70% and 69%, respectively) because of a lower sensitivity and specificity. However, IF showed a significant agreement with CSF aSyn-SAA. In conclusion, our data may favor the use of skin biopsy and aSyn-SAA as diagnostic tools for a synucleinopathy in iRBD.

Consistent skin α-synuclein positivity in REM sleep behavior disorder - A two center two-to-four-year follow-up study.

OBJECTIVE/METHODS: Phosphorylated alpha-synuclein (p-syn) in dermal nerves of patients with isolated REM sleep behavior disorder (iRBD) is detectable by immunofluorescence-labeling. Skin-biopsy-p-syn-positivity was recently postulated to be a prodromal marker of Parkinson's disease (PD) or related synucleinopathies. Here, we provide two-to four-year clinical and skin biopsy follow-up data of 33 iRBD patients, whose skin biopsy findings at baseline were reported in 2017. RESULTS: Follow-up biopsies were available from 25 patients (18 positive at baseline) and showed consistent findings over time in 24 patients. One patient converted from skin-biopsy-negativity to -positivity. P-syn-positivity was observed in iRBD patients who still had a normal FP-CIT-SPECT two years later. Clinically, five of the 23 at baseline skin-biopsy-positive patients (21.7%) had converted to PD or dementia with Lewy bodies at follow-up, but none of the skin-biopsy-negative patients. CONCLUSIONS: Dermal p-syn in iRBD is most probably an early consistent marker of synucleinopathy and may support other indicators of conversion to manifest disease state.

Subcutaneous immunoglobulin for maintenance therapy in stiff-person syndrome: One-year follow-up in two patients.

Stiff person syndrome is a rare condition characterised by prolonged stiffness with superimposed muscle spasms. Immunotherapy relies mainly on intravenous immunoglobulin, steroids and plasma exchange. Azathioprine or rituximab are other possible options. We describe two patients who showed a good clinical response with intravenous immunoglobulin and persistence of the clinical improvement after shifting to equivalent dosage of subcutaneous immunoglobulin. Both patients received a diagnosis of stiff person syndrome based on their clinical symptoms (episodes of stiffness and spasms) and presence of antiglutamic acid decarboxylase. Treatment with intravenous immunoglobulin was started with improvement of symptoms as reported by patients and confirmed also by the spasm frequency scale and modified Ashworth scale. After clinical stabilisation in order to avoid the hospitalisation required for intravenous immunoglobulin treatment a switch to subcutaneous immunoglobulins was made. After one year of follow-up from the switch, the patients show clinical stability. Their scores on the modified Ashworth scale, spasm frequency scale and on the 10 Meter Walking Test were also stable. Subcutaneous formulation of immunoglobulin could be as effective as intravenous immunoglobulin in the maintenance treatment of Stiff person syndrome, although studies involving a larger cohort of patients are needed in order to confirm our anecdotal experience.

Early neurological manifestations of hospitalized COVID-19 patients.

INTRODUCTION: Neurological manifestations can occur during coronavirus disease 19 (COVID-19). Several pathogenic mechanisms have been hypothesized, without conclusive results. In this study, we evaluated the most frequent neurological symptoms in a cohort of hospitalized COVID-19 patients, and also investigated the possible relationship between plasmatic inflammatory indices and olfactory disorders (ODs) and between muscle pain and creatine kinase (CK). METHODS: We consecutively enrolled hospitalized COVID-19 patients. A structured questionnaire concerning typical and neurological symptoms, focusing on headache, dizziness, ODs, taste disorders (TDs), and muscle pain, was administrated by telephone interviews. RESULTS: Common neurological symptoms were reported in the early phase of the disease, with a median onset ranging from 1 to 3 days. Headache showed tension-type features and was more frequently associated with a history of headache. Patients with ODs less frequently needed oxygen therapy. Inflammatory indices did not significantly differ between patients with and without ODs. Muscle pain did not show any association with CK level but was more frequently associated with arthralgia and headache. CONCLUSION: In our cohort, ODs were an early symptom of COVID-19, more frequently reported by patients with milder forms of disease. Headache in association with arthralgia and muscle pain seems to reflect the common symptoms of the flu-like syndrome, and not COVID-19 infection-specific.

Denervation findings on EMG in amyotrophic lateral sclerosis and correlation with prognostic milestones: Data from a retrospective study.

OBJECTIVE: To verify whether the finding of denervation activity on EMG at the time of diagnosis has a prognostic value in amyotrophic lateral sclerosis (ALS). METHODS: We retrospectively studied all the patients discharged with a diagnosis of ALS between January 2009 and January 2017. 92 patients met the inclusion criteria. We mainly verified three prognostic targets:All EMG examinations were reviewed and a denervation score (DS) was calculated. The association of DS with clinical milestones was analysed, adjusting for disease duration, age , sex, and clinical phenotype. RESULTS: We found a significant association between bulbar DS and time to NIV/tracheostomy (HR: 3.34, 95% CI: 1.49 to 7.48, p = 0.002) and with survival (HR 3.633, 95% CI 1.681-7.848, p = 0.001), regardless of the clinical phenotype. Furthermore, we found a significant influence of a general DS on survival (HR: 2.62, 95% CI 1.335-5.160, p = 0.005). CONCLUSION: EMG assessment could be of value not just for ALS diagnosis but also for its intrinsic prognostic value. SIGNIFICANCE: EMG could provide additional information about the rate of progression of ALS as early as the diagnosis is made.

Subgroup comparison according to clinical phenotype and serostatus in autoimmune encephalitis: a multicenter retrospective study.

BACKGROUND AND PURPOSE: Autoimmune encephalitides (AE) include a spectrum of neurological disorders whose diagnosis revolves around the detection of neuronal antibodies (Abs). Consensus-based diagnostic criteria (AE-DC) allow clinic-serological subgrouping of AE, with unclear prognostic implications. The impact of AE-DC on patients' management was studied, focusing on the subgroup of Ab-negative-AE. METHODS: This was a retrospective multicenter study on patients fulfilling AE-DC. All patients underwent Ab testing with commercial cell-based assays (CBAs) and, when available, in-house assays (immunohistochemistry, live/fixed CBAs, neuronal cultures) that contributed to defining final categories. Patients were classified as Ab-positive-AE [N-methyl-d-aspartate-receptor encephalitis (NMDAR-E), Ab-positive limbic encephalitis (LE), definite-AE] or Ab-negative-AE (Ab-negative-LE, probable-AE, possible-AE). RESULTS: Commercial CBAs detected neuronal Abs in 70/118 (59.3%) patients. Testing 37/48 Ab-negative cases, in-house assays identified Abs in 11 patients (29.7%). A hundred and eighteen patients fulfilled the AE-DC, 81 (68.6%) with Ab-positive-AE (Ab-positive-LE, 40; NMDAR-E, 32; definite-AE, nine) and 37 (31.4%) with Ab-negative-AE (Ab-negative-LE, 17; probable/possible-AE, 20). Clinical phenotypes were similar in Ab-positive-LE versus Ab-negative-LE. Twenty-four/118 (20.3%) patients had tumors, and 19/118 (16.1%) relapsed, regardless of being Ab-positive or Ab-negative. Ab-positive-AE patients were treated earlier than Ab-negative-AE patients (P = 0.045), responded more frequently to treatments (92.3% vs. 65.6%, P < 0.001) and received second-line therapies more often (33.3% vs. 10.8%, P = 0.01). Delays in first-line therapy initiation were associated with poor response (P = 0.022; odds ratio 1.02; confidence interval 1.00-1.04). CONCLUSIONS: In-house diagnostics improved Ab detection allowing better patient management but was available in a patient subgroup only, implying possible Ab-positive-AE underestimation. Notwithstanding this limitation, our findings suggest that Ab-negative-AE and Ab-positive-AE patients share similar oncological profiles, warranting appropriate tumor screening. Ab-negative-AE patients risk worse responses due to delayed and less aggressive treatments.

Sleep-related disorders and their relationship with MRI findings in multiple sclerosis.

Sleep-related disorders have been reported to have a higher prevalence in multiple sclerosis (MS) than in the general population. They are often undervalued for the presence of more severe physical problems and the occurrence at night, without a direct observation in common clinical practice, but if not recognized and treated they can negatively affect the quality of life causing daytime drowsiness and worsening fatigue. Sleep related disorders most commonly reported in MS are as follows: insomnia, sleep-related breathing disorders (SRBD), restless legs syndrome (RLS) and periodic limb movement disorders (PLMD). Secondary narcolepsy, REM sleep behavior disorder (RBD) and propriospinal myoclonus have been also described in some case reports or series. The purpose of this review is to correlate the more common sleep disturbances in MS patients to the involvement of specific brain regions, analyzing their relationship with MRI findings. While insomnia is usually secondary to other disabling symptoms such as nocturia or pain, SRBD, RLS, narcolepsy, RBD and propriospinal myoclonus in MS patients can be the consequence of an injury of specific central nervous system (CNS) areas. Lesions in the pontine tegmentum and the dorsal medulla have been associated with SRBD, spinal cord lesions or atrophy with RLS, bilateral lesions in the lateral hypothalamus with narcolepsy-like symptoms, lesions in the dorsal pontine tegmentum with RBD and intramedullary demyelinating plaques in spinal cord with propriospinal myoclonus. MS specialists and general neurologists should be aware of these comorbidities since neuroimaging, which is routinely performed in MS, could provide helpful clinical indications on patients with secondary sleep-related disorders and to categorize symptomatic patients who need to underdo more in-depth sleep studies.

Abnormal α-synuclein deposits in skin nerves: intra- and inter-laboratory reproducibility.

BACKGROUND AND PURPOSE: Visualization of phosphorylated α-synuclein at serine 129 (p-syn) in skin nerves is a promising test for the in vivo diagnosis of synucleinopathies. Here the aim was to establish the intra- and inter-laboratory reproducibility of measurement of intraneural p-syn immunoreactivity in two laboratories with major expertise (Würzburg and Bologna). METHODS: In total, 43 patients affected by Parkinson's disease (PD 21 patients), dementia with Lewy bodies (DLB 1), rapid eye movement sleep behaviour disorder (RBD 11), multiple system atrophy (MSA-P 4) and small fibre neuropathy (SFN 6) were enrolled. Skin biopsy was performed at the C7 paravertebral spine region and distal skin sites (thigh or leg). The analysis was standardized in both laboratories and carried out blinded on a single skin section double stained with antibodies to p-syn and the pan-axonal marker protein gene product 9.5. Fifty skin sections were randomly selected for the analysis: 25 from C7 and 25 from distal sites. Differently classified sections were re-evaluated to understand the reasons for the discrepancy. RESULTS: The intra-laboratory analysis showed an excellent reproducibility both in Würzburg (concordance of classification 100% of sections; K = 1; P < 0.001) and Bologna (96% of sections; K = 0.92; P < 0.001). Inter-laboratory analysis showed reproducibility in 45 sections (90%; K = 0.8; P < 0.001) and a different classification in five sections, which was mainly due to fragmented skin samples or weak fluorescent signals. CONCLUSIONS: Analysis of p-syn showed excellent inter- and intra-laboratory reproducibility supporting the reliability of this technique. The few ascertained discordances were important to further improve the standardization of this technique.

Functional MRI study in a case of Charles Bonnet syndrome related to LHON.

INTRODUCTION: Charles Bonnet syndrome is characterized by simple or complex visual hallucinations (VH) due to damage along the visual pathways. We report a functional MRI study of brain correlates of VH in the context of a severe optic atrophy in a patient with Leber's Hereditary Optic Neuropathy (LHON). CASE REPORT: A 62-year-old man was diagnosed with LHON (11778/ND4 mtDNA mutation) after subacute visual loss in left eye (right eye was amblyopic). One month later, he experienced VH of a few seconds consisting in "moving red and blue miniature cartoons". One year later VH content changed in colored mosaic (10-15 s duration), usually stress-related, and blue and white flashes (2-5 s), triggered by unexpected auditory stimuli. Audiometry revealed mild sensorineural hearing loss. Three block design functional MRI paradigms were administrated: 1) random "clap", 2) "checkerboard" and 3) non-random "beep". After random "claps" simple flashes were evoked with bilateral activation of primary and secondary visual cortex, cuneus, precuneus and insula. Neither hallucinations nor cortex activation were registered after "checkerboard" stimulation, due to the severe visual impairment. Primary and secondary auditory cortices were "beep"-activated, without eliciting VH by non-random "beep". CONCLUSIONS: The peculiarity of our case is that VH were triggered by random auditory stimuli, possibly due to a cross-modal plasticity between visual and auditory networks, likely influenced by the sensorineural deafness. Functional alterations of both networks in resting conditions have been demonstrated in LHON patients, even without an auditory deficit. Finally, the absence of VH triggered by expected stimuli is consistent with the "expectation suppression theory", based on increased neural activations after unexpected but not by predicted events.

Diagnostic criteria for amyotrophic lateral sclerosis: A multicentre study of inter-rater variation and sensitivity.

OBJECTIVE: This study assesses inter-rater agreement and sensitivity of diagnostic criteria for amyotrophic lateral sclerosis (ALS). METHODS: Clinical and electrophysiological data of 399 patients with suspected ALS were collected by eleven experienced physicians from ten different countries. Eight physicians classified patients independently and blinded according to the revised El Escorial Criteria (rEEC) and to the Awaji Criteria (AC). Inter-rater agreement was assessed by Kappa coefficients, sensitivity by majority diagnosis on 350 patients with follow-up data. RESULTS: Inter-rater agreement was generally low both for rEEC and AC. Agreement was best on the categories "Not-ALS", "Definite", and "Probable", and poorest for "Possible" and "Probable Laboratory-supported". Sensitivity was equal for rEEC (64%) and AC (63%), probably due to downgrading of "Probable Laboratory-supported" patients by AC. However, AC was significantly more effective in classifying patients as "ALS" versus "Not-ALS" (p < 0.0001). CONCLUSIONS: Inter-rater variation is high both for rEEC and for AC probably due to a high complexity of the rEEC inherent in the AC. The gain of AC on diagnostic sensitivity is reduced by the omission of the "Probable Laboratory-supported" category. SIGNIFICANCE: The results highlight a need for initiatives to develop simpler and more reproducible diagnostic criteria for ALS in clinical practice and research.

Procedures in endoscope reprocessing and monitoring: an Italian survey.

BACKGROUND: The high diffusion of endoscopes worldwide and the need for effective reprocessing methods requested the development of guidelines and implementation of surveillance procedures at local level. STUDY DESIGN: In order to collect data on everyday's practice and adherence to available guidelines, endoscopy units from different public institutions were surveyed using a dedicated questionnaire. METHODS: Between July and November 2015 a survey was carried in 12 main hospitals from 10 different Italian regions, involving 22 endoscopy units. The state of the art of national and international guidelines was investigated to compare the protocols adopted at local level. RESULTS: In all the surveyed hospitals, the reprocessing activity is based on pre-established protocols in adherence with principal guidelines. Enzymatic detergents, which are recommended by the international guidelines, are used in 55.6% of units and peracetic acid is currently the most widely used chemical disinfectant. Discrepancies were observed in the application of periodic quality controls. CONCLUSION: Updated guidelines are generally applied in reprocessing practice. Quality controls may represent a critical issue to improve effectiveness and surveillance. The whole of acquired data can promote a positive trend towards the application of best practices.

Skin α-synuclein deposits differ in clinical variants of synucleinopathy: an in vivo study.

We aimed to characterize in vivo α-synuclein (α-syn) aggregates in skin nerves to ascertain: 1) the optimal marker to identify them; 2) possible differences between synucleinopathies that may justify the clinical variability. We studied multiple skin nerve α-syn deposits in 44 patients with synucleinopathy: 15 idiopathic Parkinson's disease (IPD), 12 dementia with Lewy Bodies (DLB), 5 pure autonomic failure (PAF) and 12 multiple system atrophy (MSA). Ten healthy subjects were used as controls. Antibodies against native α-syn, C-terminal α-syn epitopes such as phosphorylation at serine 129 (p-syn) and to conformation-specific for α-syn mature amyloid fibrils (syn-F1) were used. We found that p-syn showed the highest sensitivity and specificity in disclosing skin α-syn deposits. In MSA abnormal deposits were only found in somatic fibers mainly at distal sites differently from PAF, IPD and DLB displaying α-syn deposits in autonomic fibers mainly at proximal sites. PAF and DLB showed the highest p-syn load with a widespread involvement of autonomic skin nerve fibers. IN CONCLUSION: 1) p-syn in skin nerves was the optimal marker for the in vivo diagnosis of synucleinopathies; 2) the localization and load differences of aggregates may help to identify specific diagnostic traits and support a different pathogenesis among synucleinopathies.

Correction to: The Italian Dystonia Registry: rationale, design and preliminary findings.

In the original article, Gina Ferrazzano was affiliated to Department of Neurology and Psychiatry, Neuromed Institute IRCCS, Sapienza University of Rome, Pozzilli, Italy.The corrected affiliation should be: Neuromed Institute IRCCS, Pozzilli, IS, Italy.

The role of skin biopsy in differentiating small-fiber neuropathy from ganglionopathy.

BACKGROUND AND PURPOSE: We aimed to test the clinical utility of the leg:thigh intraepidermal nerve-fiber (IENF) density ratio as a parameter to discriminate between length-dependent small-fiber neuropathy (SFN) and small-fiber sensory ganglionopathy (SFSG) in subjects with signs and symptoms of small-fiber pathology. METHODS: We retrospectively evaluated thigh and leg IENF density in 314 subjects with small-fiber pathology (173 with distal symmetrical length-dependent SFN and 141 with non-length-dependent SFSG). A group of 288 healthy subjects was included as a control group. The leg:thigh IENF density ratio was calculated for all subjects. We used receiver operating characteristic curve analyses to assess the ability of this parameter to discriminate between length-dependent SFN and SFSG, and the decision curve analysis to estimate its net clinical benefit. RESULTS: In patients with neuropathy, the mean IENF density was 14.8 ± 6.8/mm at the thigh (14.0 ± 6.9/mm in length-dependent SFN and 15.9 ± 6.7/mm in patients with SFSG) and 7.5 ± 4.5/mm at the distal leg (5.4 ± 3.2/mm in patients with length-dependent SFN and 10.1 ± 4.6/mm in patients with SFSG). The leg:thigh IENF density ratio was significantly (P < 0.01) lower in patients with length-dependent SFN (0.44 ± 0.23) compared with patients with SFSG (0.68 ± 0.28). The area under the curve of the receiver operating characteristic analysis to discriminate between patients with length-dependent SFN and SFSG was 0.79. The decision curve analysis demonstrated the clinical utility of this parameter. CONCLUSIONS: The leg:thigh IENF ratio represents a valuable tool in the differential diagnosis between SFSG and length-dependent SFN.

Absent cardiac and muscle sympathetic nerve activities involvement in Ross syndrome: A follow-up study.

PURPOSE: Ross syndrome (RS) is characterized by selective involvement of post-ganglionic skin sympathetic nerve fibres. We report a follow-up study in 4 patients to clarify whether in RS autonomic dysfunction spreads affecting also cardiovascular system. METHODS: The patients underwent cardiovascular reflexes (CVR) and microneurography recording of muscle sympathetic nerve activity (MSNA) for a follow-up mean period of 5years. RESULTS: CVR and MSNA were normal at baseline and unchanged over the follow-up. CONCLUSIONS: Cardiovascular autonomic system is spared in RS differently from skin autonomic activity dysfunction which progress over time. However, before drawing any definite conclusion, a large cohort of patients needs to be studied.

Added value of electromyography in the diagnosis of myopathy: A consensus exercise.

OBJECTIVE: Currently, neurologists may primarily rely on blood biomarkers, muscle biopsy, MRI, and genetics in the diagnostic work-up of suspected myopathy. Using expert consensus as diagnostic reference standard, this study addressed the added value of electrodiagnostic medicine (EDX) in diagnosis of myopathies. METHODS: One hundred ninety-four EDX evaluations of patients with a peer-review consensus diagnosis of myopathy were collected by seven European centres. Each patient was given three different consensus diagnoses: (1) the EDX diagnosis solely based on EDX results, (2) the pure clinical diagnosis based on all available information except EDX results, and (3) the final diagnosis including EDX and all additional information. The myopathies were grouped as muscular dystrophy (45), inflammatory myopathy (46), other aetiology (36) or unknown aetiology (67). RESULTS: Higher diagnostic probabilities for myopathy were seen in the final diagnosis compared to the pure clinical diagnosis (p<0.001). Adding EDX information increased the diagnostic probability of myopathy in 67 patients (34.4%). The greatest increase was seen for myopathies of unknown aetiology. CONCLUSIONS: EDX has a major impact in the diagnosis of myopathies of unknown aetiology. In genetically or biopsy proven myopathies, EDX generally supports the diagnosis. SIGNIFICANCE: EDX is still a useful tool in the diagnostic work-up of most patients with suspected myopathy.