Onasemnogene Abeparvovec Treatment after Nusinersen in an Infant with Spinal Muscular Atrophy Type 1.

BACKGROUND: Until recently, the treatment of spinal muscular atrophy (SMA) was limited to symptomatic treatment with no cure. Three innovative drugs, nusinersen, onasemnogene abeparvovec (OA), and risdiplam have been developed to treat SMA. Although the clinical trials for these drugs have demonstrated their efficacy, there is limited information on real world treatment strategies. In this study, we present a case of a male infant with SMA type 1 who underwent OA treatment after nusinersen treatment. CASE PRESENTATION: At 4 months of age, the patient was diagnosed with SMA type 1. At 6 months of age, nusinersen treatment was initiated. His motor function improved, but the effect was limited; therefore, his parents requested gene replacement therapy. During the preparation for OA treatment, anti-adeno-associated virus 9 (AAV9) antibody tests repeatedly showed non-specific reactions, which delayed initiation of treatment. The patient was put on ventilator management after he caught a common cold. During this management, the anti-AAV9 antibody test results were negative. Furthermore, the patient showed increased transaminase levels just before OA treatment; however, since these gradually decreased without signs of liver failure, we started OA treatment at 13 months of age. Four months later, the patient began to sit without support and was weaned from non-invasive positive pressure ventilation, although nasogastric tube feeding remained partially necessary. CONCLUSION: We believe that the management of unstable SMA type 1 symptoms, anti-AAV9 antibody testing, and changes in transaminase levels will be helpful for other patients with SMA who require treatment.

Gene therapy for spinal muscular atrophy is considerably effective when administered as early as possible after birth.

Introduction: Spinal muscular atrophy (SMA) is a neuromuscular disease characterized by muscle atrophy and progressive muscle weakness. Insurance-approved treatments in Japan include antisense oligonucleotide therapy, gene therapy, and small molecule therapy. The efficacy of these therapies varies depending on the timing of treatment initiation. Case presentation: We report the cases of two infants with SMA born in the same region. Patient 1, who had two copies of SMN2, was born before newborn screening (NBS) was started and received onasemnogene abeparvovec therapy at the age of 4 months. Patient 2, who had three copies of SMN2, was born after the start of NBS and was diagnosed and treated with onasemnogene abeparvovec before symptoms appeared. Unfortunately, Patient 1 became bedridden despite receiving gene therapy, while Patient 2 achieved normal motor development. Discussion: Our findings show that treatment timing is an essential factor affecting patients' motor neurodevelopmental outcomes, although our patients did have differences in the number of copies of SMN2. Therefore, a system should be established to allow all newborns to undergo publicly funded NBS for SMA.

Exploratory evaluation of an eye-tracking system in patients with advanced spinal muscular atrophy type I receiving nusinersen.

Objective: This study evaluated the feasibility of a matching-pair test using eye-tracking technology to assess nusinersen effectiveness in patients with advanced spinal muscular atrophy (SMA) type I. Methods: This prospective, observational study enrolled patients with 5q-SMA type I who had lost gross motor function. Three different levels of matching-pair tests were conducted using the eye-gaze system (My Tobii; TobiiDynavox Inc.) at baseline, and after 9 and 24 weeks of nusinersen treatment. The primary endpoint was the change from baseline in matching-pair test scores and response times (i.e., the time to answer matching-pair test) at 24 weeks from baseline. Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND), Pediatric Quality of Life inventory for patients with Neuromuscular Disease (PedsQL-NM) and Numerical Rating Scale (NRS) scores were also assessed as secondary endpoints. Analysis of ocular fixation was performed as an additional analysis. This study was registered at https://www.umin.ac.jp/ctr/ (UMIN000033935). Results: Seven patients (one male, six female) aged 5-21 years (median 11 years) were enrolled; all patients were bedridden and six patients were ventilated. All seven patients were able to conduct level 1 matching-pair tests at each assessment; five patients were also able to conduct levels 2 and 3. Two patients (those with the highest CHOP-INTEND scores) were able to complete all tests correctly within 60 s. There was a non-significant trend toward improvement in CHOP-INTEND, PedsQL-NM, and NRS scores over the 6-month period. There were no significant differences in the number of actions, errors, correct answers, or response times between baseline and Week 9 or 24 at any level. However, the result of an additional analysis suggests that detection of eye movement would be useful to evaluate for advanced SMA. Conclusions: Eye-tracking systems are possibly feasible for the assessment of treatment efficacy in patients with advanced SMA type I.

Truncal Instability and Titubation in Patients With Acute Encephalopathy With Reduced Subcortical Diffusion.

The present retrospective study aimed to investigate the presence of truncal instability or titubation after the first seizure and second phase in patients with acute encephalopathy with reduced subcortical diffusion (AED). Of the 15 patients with AED who were admitted to our hospital for 3 years and 2 months and had reached developmental milestones for sitting before disease onset, six experienced moderate-to-severe truncal instability while sitting after the first seizure. These patients had a significantly longer first seizure duration and significantly lower GCS scores 12-24 h after the first seizure, as well as significantly higher Tada score and Creatinine and blood glucose levels than those with mild or no truncal instability while in a seated position after the first seizure. Three 1-year-old children with bilateral frontal lobe lesions, particularly in the bilateral prefrontal lobe regions, demonstrated truncal titubation, which has not previously been reported as a clinical feature of AED. Tada score reported to be a predictor of AED prognosis and truncal instability in the sitting position after the first seizure may represent disease severity, but not the specific lesions. Conversely, truncal titubation might be suggestive of bilateral frontal lobe lesions, particularly in patients without severe instability. Further studies on the role of bilateral prefrontal lobe lesions to truncal titubation in patients with AED using more objective evaluation methods, such as stabilometry, are necessary.

Determinants of outcomes for acute encephalopathy with reduced subcortical diffusion.

Acute encephalopathy with reduced subcortical diffusion (AED), characterised by seizure onset and widespread reduced apparent diffusion coefficient in the cortex/subcortical white matter, is one of the most common acute encephalopathies in children in East Asia. This 14-year single-centre retrospective study on 34 patients with AED showed that therapeutic hypothermia was used for patients with more severe consciousness disturbance after the first seizure or second phase initiation, extrapolating from neonatal hypoxic encephalopathy and adult post-cardiac arrest syndrome. The basal ganglia/thalamus lesions and the Tada score were the poor outcome determinants in the multivariate analysis. The correlation between the worse outcomes and the duration from the first seizure to the initiation of therapeutic hypothermia was observed only in the patients with AED cooled before the second phase. This correlation was not observed in the overall AED population. There was a moderate negative association between the worse outcomes and the duration between the first seizure and the second phase. Therefore, the basal ganglia/thalamus lesions and the Tada score were the outcome determinants for patients with AED. Further investigation is required to examine the efficacy of therapeutic hypothermia in this population while considering the timing of the therapeutic hypothermia initiation and the second phase.

Brain stem infarction in a 6-year-old boy with Down syndrome.

Infarct locations in children with arterial ischemic stroke have primarily been reported to be lobar or in the basal ganglia, and those in patients with Down syndrome (DS) and antiphospholipid syndrome (APS) are typically wide and multiple. No solitary brain stem infarctions have ever been reported in children with DS until now. Here, we report a case of brain stem infarction in a 6-year-old boy with DS who had no cardiac, renal, or intestinal complications. He exhibited ataxic gait and medial longitudinal fasciculus (MLF) symptoms at first presentation. Neuroimaging revealed a localized and isolated lesion in the midbrain. Although he did not satisfy the diagnostic criteria of APS, he showed persistently elevated levels of anticardiolipin antibody (21 U/mL; normal value <10 U/mL). Although he had the risks of a multiple vascular systems disorder, DS, and persistently elevated levels of antiphospholipid antibodies, his lesion was not similar to any of the previously reported cerebral infarctions in DS or in APS. To our knowledge, this is the first report of limited solitary brain stem infarction in a child with DS.

Fulminant acute disseminated encephalomyelitis in children.

Acute disseminated encephalomyelitis (ADEM) is a typically monophasic inflammatory demyelinating disease of the central nervous system with a favorable outcome. However, 2% of ADEM involves acute hemorrhagic leukoencephalitis (AHLE), which is a fulminant and hyperacute variant of ADEM with a poor outcome and high mortality. There are limited case reports of fulminant ADEM including AHLE in children. Herein, we report two pediatric cases of fulminant ADEM. Both cases had a rapid deterioration of consciousness, repetitive seizures, and brain edema on neuroimaging, in addition to atypical neuroradiological findings on magnetic resonance imaging (MRI), a reversible splenial lesion in case 1, and bilateral frontal and occipital cortical lesions in case 2. Both cases were treated with early high-dose methyl-prednisolone and immunoglobulin, while therapeutic hypothermia was also initiated in case 2 after the patient exhibited a decerebrate posture and irregular breathing pattern. Both cases had a favorable outcome. Further case reports on pediatric fulminant ADEM are required to clarify the various clinical types, and to examine the efficacy of various treatment modalities for fulminant ADEM and AHLE in children.

A novel STXBP1 mutation causes typical Rett syndrome in a Japanese girl.

Rett syndrome (RTT) is a neurodevelopmental disorder mostly caused by mutations in Methyl-CpG-binding protein 2 (MECP2); however, mutations in various other genes may lead to RTT-like phenotypes. Here, we report the first case of a Japanese girl with RTT caused by a novel syntaxin-binding protein 1 (STXBP1) frameshift mutation (c.60delG, p.Lys21Argfs*16). She showed epilepsy at one year of age, regression of acquired psychomotor abilities thereafter, and exhibited stereotypic hand and limb movements at 3 years of age. Her epilepsy onset was earlier than is typical for RTT patients. However, she fully met the 2010 diagnostic criteria of typical RTT. STXBP1 mutations cause early infantile epileptic encephalopathy (EIEE), various intractable epilepsies, and neurodevelopmental disorders. However, the case described here presented a unique clinical presentation of typical RTT without EIEE and a novel STXBP1 mutation.