Expanding the phenotype of Brunner syndrome from childhood to adulthood: Description of the second pediatric patient and his mother.

Brunner syndrome is a recessive X-linked disorder caused by pathogenic variants in the monoamine oxidase A gene (MAOA). It is characterized by distinctive aggressive behavior, mild intellectual disability, sleep disturbances, and typical biochemical alterations deriving from the impaired monoamine metabolism. We herein describe a 5-year-old boy with developmental delay, autistic features, and myoclonic epilepsy, and his mother, who had mild intellectual disability and recurrent episodes of palpitations, headache, abdominal pain, and abdominal bloating. Whole exome sequencing allowed detection of the maternally-inherited variant c.410A>G, (p.Glu137Gly) in the MAOA gene. The subsequent biochemical studies confirmed the MAOA deficiency both in the child and his mother. Given the serotonergic symptoms associated with high serotonin levels found in the mother, treatment with a serotonin reuptake inhibitor and dietary modifications were carried out, resulting in regression of the biochemical abnormalities and partial reduction of symptoms. Our report expands the phenotypic spectrum of Brunner disease, bringing new perspectives on the behavioral and neurodevelopmental phenotype from childhood to adulthood.

Parkinson disease following COVID-19: Report of six cases.

BACKGROUND AND PURPOSE: Core clinical manifestations of COVID-19 include influenza-like and respiratory symptoms. However, it is now evident that neurological involvement may occur during SARS-CoV-2 infection, covering an extensive spectrum of phenotypical manifestations. A major challenge arising from this pandemic is represented by detecting emerging neurological complications following recovery from SARS-CoV-2 infection. To date, a few post-COVID-19-infected subjects diagnosed with Parkinson disease (PD) have been described, raising the possibility of a connection between the infection and neurodegenerative processes. Here, we describe a case series of six subjects who developed PD after COVID-19. METHODS: Patients were observed at Scientific Institute for Research and Health Care Mondino Foundation Hospital, Pavia (Italy), and San Paolo University Hospital of Milan (Italy) between March 2021 and June 2022. In all subjects, SARS-CoV-2 infection was confirmed by means of reverse transcriptase polymerase chain reaction from a nasopharyngeal swab. Subjects underwent an accurate neurological evaluation, and neuroimaging studies were performed. RESULTS: We describe six subjects who developed PD with an average time window after SARS-CoV-2 infection of 4-7 weeks. Apparently, no relationship with COVID-19 severity emerged, and no overt structural brain abnormalities were found. All subjects experienced unilateral resting tremor at onset and showed a satisfactory response to dopaminergic treatment. CONCLUSIONS: Immune responses to SARS-CoV-2 infection have been shown to shape the individual susceptibility to develop long-term consequences. We hypothesize that, in these subjects, COVID-19 has unmasked a latent neurodegenerative process. Characterization of the neuroinflammatory signatures in larger cohorts is warranted, which might provide novel insights into the pathogenesis of PD.

BoNT-A efficacy in high frequency migraine: an open label, single arm, exploratory study applying the PREEMPT paradigm.

INTRODUCTION: In this open label, single-arm trial we evaluated the efficacy of onabotulinum toxin-A in the prevention of high-frequency episodic migraine (8-14 migraine days/month). METHODS: We enrolled 32 high-frequency episodic migraine subjects (age 44.8 ± 11.9 years, 11.0 ± 2.2 migraine days, 11.5 ± 2.1 headache days, 7 females). After a 28-day baseline period, subjects underwent 4 subsequent onabotulinum toxin-A treatments according to the phase III research evaluating migraine prophylaxis therapy (PREEMPT) paradigm, 12-weeks apart. The primary outcome was the reduction of monthly migraine days from baseline in the 12-week period following the last onabotulinum toxin-A treatment. RESULTS: Onabotulinum toxin-A reduced monthly migraine days by 3.68 days (-33.1%, p < 0.01). Thirty-nine percent of the patients experienced a ≥50% reduction in monthly migraine days. Onabotulinum toxin-A also reduced the number of headache days (-33.9%, p < 0.01) and the intake of acute medications (-22.9%, p = 0.03). Disability and quality of life (QoL) scores improved markedly (migraine disability assessment (MIDAS) -41.7%; migraine specific questionnaire (MSQ) -31.7%, p < 0.01). CONCLUSIONS: The findings suggest that, when administered according to the PREEMPT paradigm, onabotulinum toxin-A is effective in the prevention of high-frequency episodic migraine.Trial Registration: NCT04578782.

Polymorphism in exercise genes and respiratory function in late-onset Pompe disease.

Genetic polymorphisms influencing muscle structure and metabolism may affect the phenotype of metabolic myopathies. We here analyze the possible influence of a wide panel of "exercise genes" on the severity and progression of respiratory dysfunction in late-onset Pompe disease (LOPD). We stratified patients with comparable age and disease duration according to the severity of their respiratory phenotype, assessed by both upright FVC% and postural drop in FVC%. We included 43 patients with LOPD (25 males, age 50.8 ± 13.6 yr) with a 2-yr follow-up since the beginning of enzyme replacement therapy (ERT). Twenty-two patients showed a postural drop >25% T0, seven other patients developed it during the follow-up. We analyzed the relationship between the progression of respiratory dysfunction and genetic polymorphisms affecting muscle function and structure [angiotensin converting enzyme (ACE), α-actinin 3 (ACTN3), peroxisome proliferator-activated receptor α (PPR-α), angiotensin (AGT)], glycogen metabolism [glycogen synthase (GYS), glycogen synthase kinase-3 isoform ß (GSK3ß)], and autophagy [sirtuin 1 (SIRT1), autophagy-related gene 7 (ATG7)]. Individuals carrying two copies of the ACE D-allele shared a 24-fold increase in the risk of severe respiratory dysfunction and progression during the 2-yr follow-up. ACTN3-XX polymorphism was also associated with worse respiratory outcome. The study of exercise genes is of particular interest in respiratory muscles, due to their peculiar features, that is, continuous, low-intensity contraction and prominent recruitment of type I fibers. In line with previous observations on skeletal muscles, ACE-DD and ACTN3-XX genotypes were associated with indirect evidence of more severe respiratory phenotypes. On the contrary, polymorphisms related to autophagy and glycogen metabolism did not seem to influence respiratory muscles.NEW & NOTEWORTHY Previous reports evaluated the role of exercise genes in influencing skeletal muscle phenotype and response to ERT in LOPD. Here, we investigate the role of polymorphisms in several exercise gene, focusing on respiratory muscles. ACE-DD and ACTN3-XX polymorphisms, possibly influencing muscle properties and fiber composition, were associated with more severe respiratory phenotypes.

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.

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.

KCTD17-related myoclonus-dystonia syndrome: clinical and electrophysiological findings of a patient with atypical late onset.

INTRODUCTION: Myoclonus-dystonia is a rare syndrome typically occurring during childhood or adolescence, mainly due to SGCE pathogenic variants. Early-onset, atypical presentations of myoclonus-dystonia have recently been associated with KCTD17 variants. In these cases, laryngeal involvement was reported in the advanced stages. METHODS: We evaluated a 52-year-old man with myoclonus-dystonia and positive family history. He underwent an electromyographic investigation of vocal cord and forearm muscles. Whole-exome sequencing was also performed. RESULTS: Onset of symptoms was at 51 years with dysphonia and vocal tremor. Electromyography disclosed abductor spasmodic dysphonia and laryngeal myoclonus. The patient later developed writer's cramp, upper limb myoclonus, and blepharospasm. Botulinum toxin injection led to improvement of the writer's cramp and to a lesser extent of the spasmodic dysphonia. Genetic analysis identified a heterozygous missense variant in exon 2 of KCTD17: c.229 C > A (p.Leu77Ile), consistently predicted as damaging. CONCLUSIONS: We suggest that the KCTD17-associated phenotypic spectrum may include late onset (even in late adulthood) as well as early and prominent laryngeal involvement.

Chronic migraine and Botulinum Toxin Type A: Where do paths cross?

Migraine is a highly prevalent and disabling disorder accounted among the primary headaches. It is the expression of a complex, and not yet fully understood, pathophysiology involving the sensitization of peripheral and central nociceptive pathways. In this review we succinctly illustrate the molecular, anatomical, and functional abnormalities underlying the migraine attack that are relevant for understanding in more depth the neurobiology behind the therapeutic effect of Botulinum Toxin Type A (BoNT-A). BoNT-A has proved effective in several neurological conditions and, more recently, also in chronic migraine. Its antimigraine mechanism of action was initially thought to be limited to the periphery and interpreted as an inhibitory activity on the processes associated to the local release of neuropeptides, with subsequent induction of peripheral sensitization. Increasing experimental evidence has become available to suggest that additional mechanisms are possibly involved, including the direct/indirect inhibition of sensitization processes in central nociceptive pathways.