Electrokinesiographic Study of Oropharyngeal Swallowing in Neurogenic Dysphagia.

Electrokinesiographic study of swallowing (EKSS) can be useful for the assessment of patients with suspected or overt neurogenic dysphagia. EKSS consists of multichannel recording of the electromyographic (EMG) activity of the suprahyoid/submental muscle complex (SHEMG), the EMG activity of the cricopharyngeal muscle (CPEMG), and the laryngopharyngeal mechanogram (LPM). The LPM is an expression of the mechanical changes that the laryngopharyngeal structures undergo during the pharyngeal phase of swallowing. This method allows detailed evaluation of the magnitude, duration and temporal relations of the different events that characterize oropharyngeal swallowing, and thus in-depth exploration both of physiological deglutition mechanisms and of pathophysiological features of swallowing in neurogenic dysphagia. Furthermore, EKSS can guide dysphagia treatment strategies, allowing identification of optimal solutions for single patients. For instance, CPEMG recording can identify incomplete or absent relaxation of the upper esophageal sphincter during the pharyngeal phase of swallowing, thus suggesting a therapeutic approach based on botulinum toxin injection into the cricopharyngeal muscle. More recently, the 'shape' of SHEMG and the reproducibility of both SHEMG and LPM over repeated swallowing acts have been implemented as novel electrokinesiographic parameters. These measures could be valuable for straightforward non-invasive investigation of dysphagia severity and response to dysphagia treatment in clinical practice.

A narrative review on the role and main findings of the Videofluoroscopic Study of Swallowing in Parkison's disease.

PURPOSE: Dysphagia is a common symptom in patients with Parkinson's disease (PD), though it may go undiagnosed until severe complications arise. Dysphagia can be suspected on a clinical basis, but an instrumental assessment is mandatory to confirm its presence and evaluate pathophysiological aspects and severity of the swallowing impairment. Aim of this review is to inform the clinician and the radiologist on the importance and the main radiological findings of the Video-Fluoroscopic-Swallow-Study (VFSS) in patients with PD starting from the most recent literature data on the topic. MATERIALS AND METHODS: Databases analysis identified 98 papers (January 2000/October 2022) of which 55 were excluded after reading title, abstract and full-text. After evaluation of the selected articles and their references 7 additional papers were added. RESULTS: Fifty papers were reviewed to answer the following four main questions: Should VFSS be routinely used to screen dysphagia? Compared to other diagnostic tools, what is the role of VFSS in PD patients with suspected dysphagia? What are the main VFSS findings and technical expedients ? What is the role of VFSS in the choice of the best treatment strategy ? CONCLUSIONS: VFSS represents a gold standard technique in the diagnostic evaluation of dysphagia in PD, having a fundamental role in the identification of patients with high risk of aspiration pneumonia and also being extremely helpful to guide to the choice of treatment strategies for dysphagia.

Assessment and treatment of neurogenic dysphagia in stroke and Parkinson's disease.

PURPOSE OF REVIEW: Neurogenic dysphagia worsens quality of life and prognosis of patients with different neurological disorders. Management of neurogenic dysphagia can be challenging. This review provides a comprehensive overview of current evidence on screening, diagnosis, and treatment of neurogenic dysphagia in stroke and Parkinson's disease, suggesting clues for clinical practice. RECENT FINDINGS: The pros and cons of diagnostic techniques are discussed in the light of updated evidence. Findings from recent meta-analyses of different treatment approaches, including traditional dysphagia therapy, peripheral and central neurostimulation techniques, and treatment with botulinum toxin, are critically discussed, emphasizing inconsistencies and controversial issues. SUMMARY: Screening tests and clinical swallow examination should be routinely performed in neurological patients at risk for dysphagia. In patients testing positive for dysphagia, first-line instrumental investigations, represented by fiberoptic endoscopic evaluation of swallowing or videofluoroscopic swallow study, should be performed to confirm the presence of dysphagia, to assess its severity, and to inform the treatment. Second-line and third-line instrumental methods can be used in selected patients to clarify specific pathophysiological aspects of oropharyngeal dysphagia. Treatment strategies should be personalized, and combination of traditional dysphagia therapy with innovative treatment approaches may increase the chance of restoring effective and safe swallowing.

Diagnostic and Prognostic Value of External Anal Sphincter EMG Patterns in Multiple System Atrophy.

BACKGROUND: It is debated whether external anal sphincter (EAS) electromyography can distinguish between multiple system atrophy (MSA) and Parkinson's disease (PD), whereas its usefulness for MSA prognosis is unknown. OBJECTIVES: We explored the diagnostic and prognostic value and clinical correlations of EAS electromyography patterns in MSA. METHODS: We collected clinical data and EAS electromyography findings in 72 patients with MSA and 21 with PD. RESULTS: We identified four EAS patterns. The normal pattern was frequently observed in PD and associated with prolonged survival when identified in MSA. Abnormal patterns were predominant in MSA. The most severe pattern was associated with the highest likelihood of MSA diagnosis and with the worst prognosis in the MSA cohort. MSA patients with EAS abnormalities often showed urogenital symptoms and fecal incontinence. CONCLUSIONS: The increasing severity of EAS electromyography patterns paralleled diagnostic accuracy and survival in MSA, and correlated with prevalence of bladder and bowel symptoms. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Respiratory failure due to concomitant interstitial lung disease and diaphragmatic involvement in a patient with anti-MDA5 dermatomyositis: a case report.

Diaphragm myositis is a rare manifestation of idiopathic inflammatory myopathies, barely portrayed in literature despite its potential severity. We describe a 57-year-old Caucasian male with anti-MDA5 positive dermatomyositis, that had a 4-month history of progressive dyspnoea requiring oxygen-therapy, scarcely responsive to prednisolone. Chest high resolution computed tomography (HRCT) showed mild interstitial lung disease (ILD), whereas pulmonary function tests evidenced severe restrictive syndrome with high lung ultrasound score. Diaphragm ultrasound revealed a marked diaphragm dysmotility, confirmed by electromyography (EMG). The patient was treated with intravenous immunoglobulins and mofetil mycophenolate with progressive improvement of dyspnoea, lung volumes and ILD at CT scan. Ultrasound examination also revealed marked improvement of the diaphragmatic disfunction and a reduction of lung ultrasound score. The use of ultrasound may provide a valuable tool in the diagnosis of diaphragm myositis, which may play a major role in the respiratory impairment of these patients. A combined lung and diaphragm examination allowed bedside monitoring of the improvements in both lung aeration and diaphragm contractility.

RFC1 expansions are a common cause of idiopathic sensory neuropathy.

After extensive evaluation, one-third of patients affected by polyneuropathy remain undiagnosed and are labelled as having chronic idiopathic axonal polyneuropathy, which refers to a sensory or sensory-motor, axonal, slowly progressive neuropathy of unknown origin. Since a sensory neuropathy/neuronopathy is identified in all patients with genetically confirmed RFC1 cerebellar ataxia, neuropathy, vestibular areflexia syndrome, we speculated that RFC1 expansions could underlie a fraction of idiopathic sensory neuropathies also diagnosed as chronic idiopathic axonal polyneuropathy. We retrospectively identified 225 patients diagnosed with chronic idiopathic axonal polyneuropathy (125 sensory neuropathy, 100 sensory-motor neuropathy) from our general neuropathy clinics in Italy and the UK. All patients underwent full neurological evaluation and a blood sample was collected for RFC1 testing. Biallelic RFC1 expansions were identified in 43 patients (34%) with sensory neuropathy and in none with sensory-motor neuropathy. Forty-two per cent of RFC1-positive patients had isolated sensory neuropathy or sensory neuropathy with chronic cough, while vestibular and/or cerebellar involvement, often subclinical, were identified at examination in 58%. Although the sensory ganglia are the primary pathological target of the disease, the sensory impairment was typically worse distally and symmetric, while gait and limb ataxia were absent in two-thirds of the cases. Sensory amplitudes were either globally absent (26%) or reduced in a length-dependent (30%) or non-length dependent pattern (44%). A quarter of RFC1-positive patients had previously received an alternative diagnosis, including Sjögren's syndrome, sensory chronic inflammatory demyelinating polyneuropathy and paraneoplastic neuropathy, while three cases had been treated with immune therapies.

Characterization and management of neurological adverse events during immune-checkpoint inhibitors treatment: an Italian multicentric experience.

BACKGROUND: Neurological immune-related adverse events (nirAEs) are rare toxicities of immune-checkpoint inhibitors (ICI). With the increase of ICI oncological indications, their incidence is growing. Their recognition and management remain nevertheless challenging. METHODS: A national, web-based database was built to collect cases of neurological symptoms in patients receiving ICI and not attributable to other causes after an adequate workup. RESULTS: We identified 27 patients who developed nirAEs (20 males, median age 69 years). Patients received anti-PD1/PDL1 (78%), anti-CTLA4 (4%), or both (19%). Most common cancers were melanoma (30%) and non-small cell lung cancer (26%). Peripheral nervous system was mostly affected (78%). Median time to onset was 43.5 days and was shorter for peripheral versus central nervous system toxicities (36 versus 144.5 days, p = 0.045). Common manifestations were myositis (33%), inflammatory polyradiculoneuropathies (33%), and myasthenia gravis (19%), alone or in combination, but the spectrum of diagnoses was broad. Most patients received first-line glucocorticoids (85%) or IVIg (15%). Seven patients (26%) needed second-line treatments. At last follow-up, four (15%) patients were deceased (encephalitis, 1; myositis/myasthenia with concomitant myocarditis, 2; acute polyradiculoneuropathy, 1), while seven (26%) had a complete remission, eight (30%) partial improvement, and six (22%) stable/progressing symptoms. ICI treatment was discontinued in most patients (78%). CONCLUSIONS: Neurological irAEs are rare but potentially fatal. They primarily affect neuromuscular structures but encompass a broad range of presentations. A prompt recognition is mandatory to timely withheld immunotherapy and administrate glucocorticoids. In corticoresistant or severely affected patients, second-line treatments with IVIg or plasmapheresis may result in additional benefit.

Buprenorphine may be effective for treatment of paramyotonia congenita.

INTRODUCTION/AIMS: Paramyotonia congenita (PMC) is a skeletal muscle sodium channelopathy characterized by paradoxical myotonia, cold sensitivity, and exercise/cold-induced paralysis. Treatment with sodium-channel-blocking antiarrhythmic agents may expose patients to a risk of arrhythmia or may be poorly tolerated or ineffective. In this study we explored the effectiveness of non-antiarrhythmic sodium-channel blockers in two patients with PMC. METHODS: Earlier treatment with mexiletine was discontinued for gastrointestinal side effects in one of the patients and lack of clinical benefit in the other. One patient received lacosamide, ranolazine, and buprenorphine, and the other was given buprenorphine only. Drug efficacy was assessed by clinical scores, timed tests, and by long and short exercise tests. RESULTS: In both patients, buprenorphine improved pain scores by at least 50%, stiffness and weakness levels, and handgrip/eyelid-opening times. The fall in compound muscle action potential (CMAP) during short exercise normalized in both patients at baseline, and improved after cooling. During long exercise, one patient showed an earlier recovery of CMAP, and the other patient had a less severe decrease (<60%). With buprenorphine, the fall in CMAP induced by cooling normalized in one patient (from -72% to -4%) and improved (from -49% to -37%) in the other patient. DISCUSSION: Buprenorphine showed promising results for the treatment of exercise-induced paralysis and cold intolerance in the two patients assessed. The exercise test may be useful for quantitative assessment of treatment response. Further studies on a larger number of patients, under carefully controlled conditions, should be considered to address the effectiveness and long-term tolerability of this therapeutic option.

COVID-19 in patients with myasthenia gravis: Epidemiology and disease course.

INTRODUCTION/AIMS: Coronavirus disease 2019 (COVID-19), a disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, has become a global pandemic. Patients with myasthenia gravis (MG), often treated with immunosuppressants, might be at higher risk of developing COVID-19 and of demonstrating a severe disease course. We aimed to study prevalence and describe features of COVID-19 in MG patients. METHODS: In May 2020, we conducted telephonic interviews with MG patients followed at our referral center. We collected structured data regarding MG and COVID-19, which was diagnosed as probable or confirmed according to the European Centre for Disease Prevention and Control case definition. We compared confirmed-COVID-19 prevalence calculated from the beginning of the pandemic in MG patients with that of the overall Pavia district. RESULTS: We interviewed 162 MG patients (median age, 66 y; interquartile range 41-77; males 59.9%), 88 from the Pavia district. Three patients had SARS-CoV-2-confirmed by polymerase chain reaction and eight had probable-COVID-19. In the Pavia district, the prevalence of confirmed-COVID-19 among MG patients (1/88, 1.14%) and overall population (4777/546 515, 0.87%) did not differ (P = .538). Higher Myasthenia Gravis Foundation of America clinicalclass and the need for recent rescue treatment, but not ongoing immunosuppressive treatments, were associated with COVID-19 risk. Of 11 MG patients with probable/confirmed-COVID-19, 3 required ventilator support, and 2 elderly patients died of COVID-19 respiratory insufficiency. Only 1 of11 patients experienced worsening MG symptoms, which improved after increasing their steroid dose. DISCUSSION: The risk of COVID-19 in MG patients seems to be no higher than that of the general population, regardless of immunosuppressive therapies. In our cohort, COVID-19 barely affected MG course.

Expression pattern of matrix metalloproteinases-2 and -9 and their tissue inhibitors in patients with chronic inflammatory demyelinating polyneuropathy.

BACKGROUND: Matrix metalloproteinases (MMPs) are a heterogeneous family of endopeptidases that play a role in many physiological functions, including the immune response. An imbalance between the activity of MMPs and their physiological tissue inhibitors (TIMPs) has been proposed in the pathophysiology of different autoimmune disorders. We aimed to assess the plasmatic levels of MMP-2, MMP-9, and their inhibitors TIMP-1 and -2 in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). SUBJECTS AND METHODS: Twenty patients with CIDP and 20 age- and sex-matched healthy controls were enrolled. Plasma concentrations of MMP-2, MMP-9, TIMP-1, and TIMP-2 were determined by the enzyme-linked immunosorbent assay. RESULTS: CIDP subjects had higher MMP-9 concentrations along with TIMP-1 downregulation when compared to controls, with the consequent increase in the MMP-9/TIMP-1 ratio (p<0.000002 for all measures). Conversely, the concentration of MMP-2 was lower in the CIDP group (p<0.01) without changes in the TIMP-2 concentration. The MMP-2/TIMP-2 ratio was decreased in the patients' group (p<0.02). DISCUSSION: We provide first preliminary evidence that the plasmatic pattern of MMPs and TIMPs is markedly altered in patients with CIDP. Future studies are needed to assess the potential usefulness of these new biomarkers in the clinical setting.

A pilot study assessing T1-weighted muscle MRI in amyotrophic lateral sclerosis (ALS).

The authors set out to study the role of T1-weighted muscle MRI in the diagnostic phase of ALS, comparing images from ten patients and nine age-matched healthy controls (HCs). All subjects underwent MRI of 68 muscles in the hands, paraspinal regions and lower limbs; the images were semi-quantitatively scored. Atrophy was more frequent in muscles of ALS patients than HCs (p < 0.0001); fatty infiltration was particularly marked in iliopsoas (p = 0.046), anterior (p = 0.020) and posterior (p = 0.047) calf muscles in patients. A trend towards agreement was found between MRI and clinic-EMG data for the first dorsal interosseous, paraspinal, and tibial anterior muscles. Muscle T1-weighted MRI can distinguish ALS patients from HCs for specific regions (i.e., legs). MRI abnormalities could be found in pauci-symptomatic spinal muscles in bulbar-onset patients. Muscle MRI may be a useful diagnostic tool in ALS, in particular for muscles difficult to investigate using clinical-EMG methods.

Predictors of outcome in a large retrospective cohort of patients with transverse myelitis.

BACKGROUND: Transverse myelitis (TM) is an inflammatory disorder that can be idiopathic or associated with central nervous system autoimmune/dysimmune inflammatory diseases, connective tissue autoimmune diseases, or post-infectious neurological syndromes. Prognosis of initial TM presentations is uncertain. OBJECTIVE: To identify outcome predictors in TM. METHODS: Retrospective study on isolated TM at onset. Scores ⩾3 on the modified Rankin scale (mRS) marked high disability. RESULTS: A total of 159 patients were identified. TM was classified as follows: idiopathic (I-TM, n = 53), post-infectious (PI-TM, n = 48), associated with multiple sclerosis (MS-TM, n = 51), or neuromyelitis optica spectrum disorders/connective tissue autoimmune diseases/neurosarcoidosis ( n = 7). At follow-up (median, 55 months; interquartile range, 32-80), 42 patients were severely disabled, and patients with I-TM or PI-TM showed the worst outcomes. Predictors of disability were infectious antecedents, sphincter and pyramidal symptoms, high mRS scores, blood-cerebrospinal fluid barrier damage, lumbar magnetic resonance imaging (MRI) lesions on univariate analysis, and older age (odds ratio (OR), 1.1; 95% confidence interval (CI), 1.0-1.1), overt/subclinical involvement of the peripheral nervous system (PNS) (OR, 9.4; 95% CI, 2.2-41.0), complete TM (OR, 10.8; 95% CI, 3.4-34.5) on multivariate analysis. CONCLUSION: Our findings help define prognosis and therapies in TM at onset. Infectious antecedents and PNS involvement associate with severe prognosis. Nerve conduction studies and lumbar MRI could improve the prognostic assessment of this condition.

The role of laryngeal electromyography in vagus nerve stimulation-related vocal fold dysmotility.

Vagus nerve stimulation (VNS) is a useful tool for drug-resistant epilepsy, but it induces known laryngeal side effects, with a significant role on patients' quality of life. VNS patients may show persistent left vocal fold (LVF) palsy at rest and/or recurrent LVF adduction during stimulation. This study aims at electromyographically evaluating laryngeal muscles abnormalities in VNS patients. We compared endoscopic laryngeal evaluation data in six VNS patients with laryngeal muscle electromyography (LMEMG) carried out on the thyroarytenoid, cricothyroid, posterior cricoarytenoid, and cricopharyngeal muscles. Endoscopy showed LVF palsy at rest in 3/6 patients in whom LMEMG documented a tonic spastic activity with reduced phasic modulation. In four out of six patients with recurrent LVF adduction during VNS activation, LMEMG showed a compound muscle action potential persisting for the whole stimulation. This is the first LMEMG report of VNS-induced motor unit activation via recurrent laryngeal nerve and upper laryngeal nerve stimulation. LMEMG data were could, therefore, be considered consistent with the endoscopic laryngeal examination in all patient.

Cross-Cultural Adaptation and Validation of the Italian Version of SWAL-QOL.

The aim of the study was to evaluate the reliability and validity of the Italian SWAL-QOL (I-SWAL-QOL). The study consisted of five phases: item generation, reliability analysis, normative data generation, validity analysis, and responsiveness analysis. The item generation phase followed the five-step, cross-cultural, adaptation process of translation and back-translation. A group of 92 dysphagic patients was enrolled for the internal consistency analysis. Seventy-eight patients completed the I-SWAL-QOL twice, 2 weeks apart, for test-retest reliability analysis. A group of 200 asymptomatic subjects completed the I-SWAL-QOL for normative data generation. I-SWAL-QOL scores obtained by both the group of dysphagic subjects and asymptomatic ones were compared for validity analysis. I-SWAL-QOL scores were correlated with SF-36 scores in 67 patients with dysphagia for concurrent validity analysis. Finally, I-SWAL-QOL scores obtained in a group of 30 dysphagic patients before and after successful rehabilitation treatment were compared for responsiveness analysis. All the enrolled patients managed to complete the I-SWAL-QOL without needing any assistance, within 20 min. Internal consistency was acceptable for all I-SWAL-QOL subscales (α > 0.70). Test-retest reliability was also satisfactory for all subscales (ICC > 0.7). A significant difference between the dysphagic group and the control group was found in all I-SWAL-QOL subscales (p < 0.05). Mild to moderate correlations between I-SWAL-QOL and SF-36 subscales were observed. I-SWAL-QOL scores obtained in the pre-treatment condition were significantly lower than those obtained after swallowing rehabilitation. I-SWAL-QOL is reliable, valid, responsive to changes in QOL, and recommended for clinical practice and outcome research.

Electrophysiological Investigations of Shape and Reproducibility of Oropharyngeal Swallowing: Interaction with Bolus Volume and Age.

Electrophysiological assessment provides valuable information on physiological and pathophysiological characteristics of human swallowing. Here, new electrophysiological measures for the evaluation of oropharyngeal swallowing were assessed: (1) the activation pattern of the submental/suprahyoid EMG activity (SHEMG); (2) the reproducibility of the oral and pharyngeal phases of swallowing, by calculating the similarity index (SI) of the SHEMG (SI-SHEMG) and of the laryngeal-pharyngeal mechanogram (SI-LPM) during repeated swallows; and (3) kinesiological measures related to the LPM. An electrophysiological-mechanical method for measuring the activation pattern of the SHEMG, the SI-SHEMG, and the SI-LPM, and maximal LPM velocity and acceleration during swallowing was applied in 65 healthy subjects divided into three age groups (18-39, 40-59, 60 years or over). All the measures were assessed during three trials of eight consecutive swallows of different liquid bolus volumes (3, 12, and 20 ml). A high overall reproducibility of oropharyngeal swallowing in healthy humans was recorded. However, while values of SI-SHEMG were similar in all the age groups, the SI-LPM was found to fall significantly in the older age group. Both the SI-SHEMG and the SI-LPM were found to fall with increasing bolus volumes. The activation pattern of the SHEMG and the LPM kinesiological measures were differently modified by bolus volume and age in the older subjects with respect to the others. We describe a new approach to the electrophysiological study of swallowing based on computed semi-automatic analyses. Our findings provide insight into some previously uninvestigated aspects of oropharyngeal swallowing physiology, considered in relation to bolus volume and age. The new electrophysiological measures here described could prove useful in the clinical setting, as it is likely that they could be differently affected in patients with different kinds of dysphagia.

Reduced threshold for inhibitory homeostatic responses in migraine motor cortex? A tDCS/TMS study.

BACKGROUND AND OBJECTIVE: Neurophysiological studies in migraine have reported conflicting findings of either cortical hyper- or hypoexcitability. In migraine with aura (MwA) patients, we recently documented an inhibitory response to suprathreshold, high-frequency repetitive transcranial magnetic stimulation (hf-rTMS) trains applied to the primary motor cortex, which is in contrast with the facilitatory response observed in the healthy subjects. The aim of the present study was to support the hypothesis that in migraine, because of a condition of basal increased cortical responsivity, inhibitory homeostatic like mechanisms of cortical excitability could be induced by high magnitude stimulation. For this purpose, the hf-rTMS trains were preconditioned by transcranial direct current stimulation (tDCS), a noninvasive brain stimulation technique able to modulate the cortical excitability state. METHODS: Twenty-two MwA patients and 20 patients with migraine without aura (MwoA) underwent trains of 5-Hz repetitive transcranial magnetic stimulation at an intensity of 130% of the resting motor threshold, both at baseline and after conditioning by 15 minutes of cathodal or anodal tDCS. Motor cortical responses to the hf-rTMS trains were compared with those of 14 healthy subjects. RESULTS: We observed abnormal inhibitory responses to the hf-rTMS trains given at baseline in both MwA and MwoA patients as compared with the healthy subjects (P < .00001).The main result of the study was that cathodal tDCS, which reduces the cortical excitability level, but not anodal tDCS, which increases it, restored the normal facilitatory response to the hf-rTMS trains in both MwA and MwoA. CONCLUSIONS: The present findings strengthen the notion that, in migraine with and without aura, the threshold for inducing inhibitory mechanisms of cortical excitability might be lower in the interictal period. This could represent a protective mechanism counteracting cortical hyperresponsivity. Our results could be helpful to explain some conflicting neurophysiological findings in migraine and to get insight into the mechanisms underlying recurrence of the migraine attacks.

External anal sphincter electromyography in multiple system atrophy: implications for diagnosis, clinical correlations, and novel insights into prognosis.

Multiple system atrophy is a sporadic, progressive, adult-onset, neurodegenerative disorder characterized by autonomic dysfunction symptoms, parkinsonian features, and cerebellar signs in various combinations. An early diagnosis of multiple system atrophy is of utmost importance for the proper prevention and management of its potentially fatal complications leading to the poor prognosis of these patients. The current diagnostic criteria incorporate several clinical red flags and magnetic resonance imaging markers supporting diagnosis of multiple system atrophy. Nonetheless, especially in the early disease stage, it can be challenging to differentiate multiple system atrophy from mimic disorders, in particular Parkinson's disease. Electromyography of the external anal sphincter represents a useful neurophysiological tool for differential diagnosis since it can provide indirect evidence of Onuf's nucleus degeneration, which is a pathological hallmark of multiple system atrophy. However, the diagnostic value of external anal sphincter electromyography has been a matter of debate for three decades due to controversial reports in the literature. In this review, after a brief overview of the electrophysiological methodology, we first aimed to critically analyze the available knowledge on the diagnostic role of external anal sphincter electromyography. We discussed the conflicting evidence on the clinical correlations of neurogenic abnormalities found at external anal sphincter electromyography. Finally, we reported recent prognostic findings of a novel classification of electromyography patterns of the external anal sphincter that could pave the way toward the implementation of this neurophysiological technique for survival prediction in patients with multiple system atrophy.

Retrograde Cricopharyngeus Dysfunction effectively treated with low dose botulinum toxin. A case report from Italy.

A large constellation of hitherto unexplained symptoms including inability to burp, gurgling noises from the chest and lower neck, abdominal bloating, flatulence, painful hiccups and emetophobia was defined as Retrograde Cricopharyngeus Dysfunction (R-CPD) in 2019. First choice treatment of R-CPD involves injection of botulinum toxin into the cricopharyngeus muscle under local or general anesthesia. This treatment has been found to be effective in the vast majority of subjects, with limited adverse events and prolonged therapeutic effects. Notwithstanding, R-CPD is still a poorly understood and underestimated disease, and a specific therapeutic dosage range of botulinum toxin (BT) has not been yet established. In this report, we describe the first case of R-CPD diagnosed in Italy, successfully treated with unilateral, anesthesia-free injection of 10 units of onabotulinum toxin into the cricopharyngeus muscle, representing the lowest dose reported to date.