Diaphragm weakness in late-onset Pompe disease: A complex interplay between lower motor neuron and muscle fibre degeneration.

BACKGROUND: Late-onset Pompe disease (LOPD) patients may still need ventilation support at some point of their disease course, despite regular recombinant human alglucosidase alfa treatment. This suggest that other pathophysiological mechanisms than muscle fibre lesion can contribute to the respiratory failure process. We investigate through neurophysiology whether spinal phrenic motor neuron dysfunction could contribute to diaphragm weakness in LOPD patients. MATERIAL AND METHODS: A group of symptomatic LOPD patients were prospectively studied in our centre from January 2022 to April 2023. We collected both demographic and clinical data, as well as neurophysiological parameters. Phrenic nerve conduction studies and needle EMG sampling of the diaphragm were perfomed. RESULTS: Eight treated LOPD patients (3 males, 37.5%) were investigated. Three patients (37.5%) with no respiratory involvement had normal phrenic nerve motor responses [median phrenic compound muscle action potential (CMAP) amplitude of 0.49 mV; 1st-3rd interquartile range (IQR), 0.48-0.65]. Those with respiratory failure (under nocturnal non-invasive ventilation) had abnormal phrenic nerve motor responses (median phrenic CMAP amplitude of 0 mV; 1st-3rd IQR, 0-0.15), and were then investigated with EMG. Diaphragm needle EMG revealed both myopathic and neurogenic changes in 3 (60%) and myopathic potentials in 1 patient. In the last one, no motor unit potentials could be recruited. CONCLUSIONS: Our study provide new insights regarding respiratory mechanisms in LOPD, suggesting a contribution of spinal phrenic motor neuron dysfunction for diaphragm weakness. If confirmed in further studies, our results recommend the need of new drugs crossing the blood-brain barrier.

Nusinersen in adults with type 3 spinal muscular atrophy: long-term outcomes on motor and respiratory function.

INTRODUCTION: Nusinersen was approved for 5q spinal muscular atrophy (SMA), irrespective of age, SMA type or functional status. Nonetheless, long-term data on adults with milder phenotypes are scarce. We aimed to characterize evolution on motor and respiratory function in our cohort of adults with type 3 SMA. METHODS: We conducted a longitudinal retrospective single-center study, including adults (≥18 years) with type 3 SMA under nusinersen for > 22 months. We reported on motor scores and spirometry parameters. RESULTS: Ten patients were included, with a median follow-up of 34 months (range = 22-46). Four patients (40%) were walkers. None used non-invasive ventilation. In Revised Upper Limb Module (RULM) and Expanded Hammersmith Functional Motor Scale (HFMSE), difference of medians increased at 6, 22 and 46 months comparing to baseline (-0.5 vs. + 1.5 vs. + 2.5 in RULM; + 4.0 vs. + 7.5 vs. + 6.0 in HFMSE). Two (50%) walkers presented a clinically meaningful improvement in 6-min walk distance. We did not report any clinically meaningful decrement in motor scores. Spirometry parameters showed an increasing difference of medians in maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) (-3 vs. + 13.4 vs. + 28.7 percentage points of predicted value for MIP; + 11.8 vs. + 13.1 vs. 13.3 percentage points of predicted value for MEP). DISCUSSION: Our cohort supports a sustained benefit of nusinersen in adults with type 3 SMA, in motor and respiratory function. Multicentric studies are still warranted.

Updated Evaluation of the Safety, Efficacy and Tolerability of Tafamidis in the Treatment of Hereditary Transthyretin Amyloid Polyneuropathy.

Hereditary amyloid transthyretin (ATTRv) amyloidosis is a devastating hereditary multisystemic disease affecting predominantly the peripheral and autonomic nervous systems and the heart. ATTRv is caused by mutations in the transthyretin (TTR) gene, leading to extracellular deposition of amyloid fibrils in multiple organs including the peripheral nervous system. If untreated, it is associated with a fatal outcome 10-12 years after disease onset. Different treatments are available for patients with ATTRv polyneuropathy. Tafamidis 20 mg is approved in Europe since 2011 for early stages of ATTRv polyneuropathy (stage I - able to walk without support) and it is recommended as first-line therapy in these patients. Tafamidis is a TTR stabilizer that selectively binds to TTR and kinetically stabilizes both wild-type native TTR and mutant TTR. Consequently, it has the potential to prevent the amyloidogenic cascade initiated by TTR tetramer dissociation into its monomers and subsequent misfolding and aggregation. Tafamidis is an oral drug, taken once per day, with proved efficacy, safety and tolerability in ATTRv-PN patients as demonstrated in different clinical trials and open-label extension studies as well in clinical practice setting with around 10 years of experience. Tafamidis treatment started in the earliest stages of the disease is associated with better neurological outcomes. A multidisciplinary approach in referral centres is also fundamental for monitoring patients to assess individual response to treatment.

Trends in the diagnostic delay and pathway for amyotrophic lateral sclerosis patients across different countries.

Background: Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disease with a median survival of 2-5 years. An early diagnosis is essential for providing ALS patients the finest management possible. Studies from different countries report a similar median diagnostic delay of around 12 months, which is still far from desirable. We analyzed the diagnostic pathway in different countries in order to identify the major challenges. Methods: We studied a cohort of 1,405 ALS patients from five different centers, in four different countries (Turkey, Germany, Poland, and Portugal), which collaborated in a common database. Demographic, disease and sociocultural factors were collected. Time from first symptom onset to first medical evaluation and to diagnosis, the specialist assessment and investigations requested were analyzed. Factors contributing to diagnostic delay were evaluated by multivariate linear regression. Results: The median diagnostic delay from first symptom onset was 11 months and was similar between centers. Major differences were seen in the time from symptom onset to first medical evaluation. An earlier first medical evaluation was associated with a longer time to diagnosis, highlighting that ALS diagnosis is not straightforward in the early stages of the disease. The odds for ALS diagnosis were superior when evaluated by a neurologist and increased over time. Electromyography was decisive in establishing the diagnosis. Conclusions: We suggest that a specific diagnostic test for ALS-a specific biomarker-will be needed to achieve early diagnosis. Early referral to a neurologist and to electromyography is important for early ALS diagnosis.

Delayed Diagnosis and Diagnostic Pathway of ALS Patients in Portugal: Where Can We Improve?

Background: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease with unsatisfactory treatment options. Best management and recruitment into clinical trials requires early diagnosis. However, diagnosis is often delayed. Analysis of the diagnostic pathway and identification of the causes of diagnostic delay are imperative. Methods: We studied a cohort of 580 ALS patients followed up in our ALS clinic in Lisbon. Demographic, disease, and sociocultural factors were collected. Time from first symptom onset to diagnosis, the specialist's assessment, and investigations requested were analyzed. Predictors of diagnostic delay were evaluated by multivariate linear regression, adjusting for potential confounders. Results: The median diagnostic delay from first symptom onset was 10 months. Spinal-onset, slower disease progression, cognitive symptoms at onset, and lower income were associated with increased diagnostic delay. Most patients were first assessed by general practitioners. Patients who were first evaluated by a neurologist were more likely to be correctly diagnosed, decreasing time to diagnosis. Electromyography was decisive in establishing the diagnosis. Conclusions: Late referral from non-neurologists to a neurologist is a potentially modifiable factor contributing to significant diagnostic delay. Educational interventions targeted to non-neurologists physicians, in order to increase awareness of ALS and, consequently, promote early referral to a neurologist at a tertiary center, will be important in reducing diagnostic delay.

Mitochondrial Neurogastrointestinal Encephalomyopathy: Novel Pathogenic Mutation in Thymidine Phosphorylase Gene in a Patient from Cape Verde Islands.

Mitochondrial Neurogastrointestinal Encephalomyopathy (MNGIE) is a rare autosomal recessive disorder caused by mutations in the gene encoding the Thymidine Phosphorylase (TP). It is clinically characterized by severe gastrointestinal dysmotility, cachexia, palpebral ptosis, ophthalmoparesis, sensorimotor polyneuropathy and leukoencephalopathy. The diagnosis is established by the presence of typical clinical and neuroimaging features, positive family history, and abnormal genetic test. A 19-year-old Cape Verdean patient with a history since childhood of recurrent episodes of nausea, vomiting, diarrhoea and painful abdominal distension associated with progressive motor disability with difficulty in climbing stairs and running and clumsiness with her hands. The diagnostic workup was suggestive of MNGIE. Genetic screening of the TYMP gene identified a novel mutation (c. 1283 G>A). Patients with MNGIE have significant comorbidity and mortality, and they are frequently misdiagnosed. A better acknowledgment of this disorder is essential to permit an earlier diagnosis and to improve disease management.

Hereditary sensory autonomic neuropathy type II: Report of two novel mutations in the FAM134B gene.

Hereditary sensory autonomic neuropathy (HSAN) type II is a rare, autosomal recessive, and early onset sensory neuropathy, characterized by severe and progressive sensation impairment, leading to ulcero-mutilating complications. FAM134B gene, also known as RETREG1 gene, mutations have been reported to be associated to HSAN-IIB. We report four patients from two unrelated families who developed during childhood a sensory axonal neuropathy with variable severity and pronounced nociception impairment. Complications such as recurrent ulcerations, osteomyelitis, and osteonecrosis leading to distal amputation were noticed. Dysautonomia was mild or even absent in our group of patients. Additionally, either clinical or neurophysiological motor impairment was not uncommon. Presence of upper motor neuron signs was also a distinctive feature in two related patients. After extensive workup, two novel homozygous mutations in the FAM134B gene were identified. This report expands the clinical and genetic spectrum of HSAN type II and emphasizes the phenotype variability even within the same family.

Distal myopathy and rapidly progressive dementia associated with a novel mutation in the VCP gene: Expanding inclusion body myopathy with early-onset Paget disease and frontotemporal dementia spectrum.

Distal myopathies are a clinically and genetically heterogeneous group characterized by distal weakness at onset. Distal myopathies are classified according to age of onset, inheritance pattern, clinical features and molecular diagnosis. Inclusion body myopathy with early-onset Paget disease and fronto-temporal dementia is a rare adult late-onset disease related to valosin-containing protein gene mutations with an autosomal dominance inheritance. It is characterized by the triad of progressive myopathy, early-onset Paget disease and premature fronto-temporal dementia We report a severe phenotype in a Portuguese patient, related to a novel mutation in the valosin-containing protein gene, characterized by a severe late-onset distal myopathy and a rapidly progressive cognitive dysfunction suggesting fronto-temporal dementia. The patient did not manifest Paget disease. Family history was negative. This case emphasizes the importance of considering inclusion body myopathy with early-onset Paget disease and fronto-temporal dementia in the differential diagnosis of distal myopathies, even in the absence of family history.

Pain, sleep patterns and health-related quality of life in paediatric patients with cancer.

PURPOSE: To compare sleep and health-related quality of life (HRQOL) in children and adolescents with cancer who had pain, with those who had no pain during hospitalisation. METHOD: A prospective comparative study was used to collect data from paediatric oncology units in three countries (Portugal, Brazil, USA). Participants (n = 118; 8-18 years) completed the Quality of Life Inventory (PedsQL) Cancer module, which includes a pain subscale, and wore a wrist actigraph for at least 72 hr. RESULTS: Almost half of the participants (48.3%) reported having pain. Sleep patterns were not affected by pain. Girls, adolescents and patients diagnosed with leukaemia/lymphoma who reported pain, had significantly lower HRQOL scores. Low sleep duration and HRQOL were found, irrespectively of pain status. CONCLUSIONS: The low sleep duration and HRQOL score in children and adolescents with cancer highlight the importance of physical and psychosocial nursing interventions during hospitalisation. The mediating effect of gender, age and diagnoses on the relation between pain and HRQOL needs to be further understood.

Non-invasive evaluation of sudomotor function in patients with myasthenia gravis.

OBJECTIVES: Myasthenia gravis (MG) is an autoimmune disease associated with antibodies against the nicotinic muscle acetylcholine receptor (AChR) at the neuromuscular junction. Dysautonomia has been previously described in MG. Electrochemical skin conductance (ESC), assessed by Sudoscan®, is a non-invasive method that allows evaluation of sudomotor function. Since sweat glands are innervated by sudomotor, postganglionic, cholinergic sympathetic C-fibers, we hypothesized that ESC could be a reliable method for assessing autonomic dysfunction in MG. METHODS: ESC measurements were prospectively assessed in patients with generalized MG and in healthy controls. Patients with diabetes mellitus, anticholinergic medication or electrophysiological findings of peripheral neuropathy were excluded. Data regarding demographic and disease features were collected. Presence of autonomic symptoms in patients with MG was assessed by Compass-31. For statistical analysis we performed student t-test and Chi2 test for comparison between both groups. RESULTS: We included 24 patients (mean age of 46.4±10.6, 75% women, mean disease duration 12.5 years, 62.5% positive for AChR antibodies) and 37 controls. We found no difference in either foot (P=0.13) or hand (P=0.83) ESC measurements between patients and controls, even after correcting for age. CONCLUSION: We could not prove the presence of autonomic sympathetic dysfunction in our cohort of MG patients when assessed by Sudoscan®. In addition, Compass-31 was not a useful questionnaire in this clinical context.

Riluzole-induced recurrent pancreatitis.

Riluzole is the only drug approved for the treatment of patients with Amyotrophic Lateral Sclerosis (ALS). It is well tolerated, being the most frequent adverse effects asthenia, nausea and reversible increase of liver enzymes levels. Severe adverse effects are extremely rare. We report for the first time, two patients with sporadic limb-onset ALS who developed recurrent acute pancreatitis (AP), with portal vein thrombosis as complication, during treatment with riluzole. We suggest that AP should be considered asa probable rare and severe side effect of treatment with riluzole in patients with ALS. We believe that in patients who develop AP during treatment with riluzole, its withdrawn may prevent recurrent AP and should be discussed with patients.

Pain assessment using the adolescent pediatric pain tool: a systematic review.

BACKGROUND: The Adolescent Pediatric Pain Tool (APPT) is a multidimensional pain assessment tool designed to assess pain location (body outline diagram), intensity (word graphic rating scale) and quality (list of pain descriptors) in hospitalized children eight to 17 years of age. OBJECTIVES: To identify the age range, health conditions, settings and purpose for which APPT has been used; the components of the APPT that have been used; and the reported clinical and research utility of the APPT. METHODS: A systematic review of published studies using the APPT was performed. Studies were identified through electronic searches in CINAHL, Medline, PubMed, SciELO and PsycInfo. RESULTS: Twenty-three studies were analyzed. APPT has been used in patients between two and 68 years of age, with various acute and chronic conditions, in and out of hospital. All but six studies used the three components of the APPT. Most of the studies used the total number of sites marked, mean pain intensity and mean number of pain descriptors selected as main outcome measures; however, scoring methods varied. Studies report that the use of the APPT is relevant for clinical practice and for research. CONCLUSION: Obtaining self-report of pain using the APPT may help clinicians to tailor pain management interventions. It may also be used in studies to provide a deeper understanding of the pain experience and to examine the effectiveness of pain management interventions. However, outcome measures and methods of scoring the different components of the APPT need to be clearly identified.