Spinal muscular atrophy (SMA) is a congenital neuromuscular disorder characterized by motor neuron loss, resulting in progressive weakness. SMA is notable in the health care community because it accounts for the most common cause of infant death resulting from a genetic defect. SMA is caused by low levels of the survival motor neuron protein (SMN) resulting from SMN1 gene mutations or deletions. However, patients always harbor various copies of SMN2, an almost identical but functionally deficient copy of the gene. A genotype–phenotype correlation suggests that SMN2 is a potent disease modifier for SMA, which also represents the primary target for potential therapies. Increasing comprehension of SMA pathophysiology, including the characterization of SMN1 and SMN2 genes and SMN protein functions, has led to the development of multiple therapeutic approaches. Until the end of 2016, no cure was available for SMA, and management consisted of supportive measures. Two breakthrough SMN-targeted treatments, either using antisense oligonucleotides (ASOs) or virus-mediated gene therapy, have recently been approved. These two novel therapeutics have a common objective: to increase the production of SMN protein in MNs and thereby improve motor function and survival. However, neither therapy currently provides a complete cure. Treating patients with SMA brings new responsibilities and unique dilemmas. As SMA is such a devastating disease, it is reasonable to assume that a unique therapeutic solution may not be sufficient. Current approaches under clinical investigation differ in administration routes, frequency of dosing, intrathecal versus systemic delivery, and mechanisms of action. Besides, emerging clinical trials evaluating the efficacy of either SMN-dependent or SMN-independent approaches are ongoing. This review aims to address the different knowledge gaps between genotype, phenotypes, and potential therapeutics.

Posterior reversible encephalopathy syndrome (PRES) is a novel clinicoradiological syndrome characterized by convulsions, headache, altered mentality, and impaired vision, which are usually accompanied by hypertension. As its nomination, PRES is usually diagnosed according to the presence of typical neuroimage showing vasogenic edema predominately involving the posterior brain area. With the widespread utilization of magnetic resonance imaging (MRI), PRES is becoming more perceptible in different medical fields. Compared to adult cases, childhood PRES seems to have a broader clinical and neuroradiological spectrum. PRES can be associated with various underlying comorbidities, medication use, and therapeutic modalities in children with diverse neurological manifestations. Moreover, pediatric patients with PRES have a more significant propensity for atypical MRI findings beyond the typically posterior cerebral areas. The knowledge of typical and atypical presentations in children is essential to avoid misdiagnosing or missing PRES, which is a potentially treatable entity. Early supportive care is the mainstay of treatment, with particular attention to the treatment of hypertension with rigorous attention to all body systems. Prompt identification and symptom-directed management are imperative to achieve a reversible prognosis in childhood PRES. Future studies specially designed for the child population are required to determine potential outcome predictors, and further, to develop novel strategies of neuroprotection in childhood PRES.

Objective: The purpose of this study was to evaluate the safety and efficacy of hydroxyurea (HU) in spinal muscular atrophy (SMA) in a randomized, double-blind, placebo-controlled trial. Methods: Twenty-eight patients with type 2 SMA and 29 patients with type 3 SMA were randomly assigned (2:1) to receive HU or matching placebo for 18 months. HU was initiated at 10 mg/kg/day with an 8-week titration to 20 mg/kg/day. Subjects were assessed at baseline (T0) and monthly for the first 2 months (T1–T2) and then every 2 months throughout treatment (T3–T10) and posttreatment periods (T11–T13). The primary outcome measures were the Gross Motor Function Measure (GMFM), Manual Muscle Test (MMT), and serum full-length survivor motor neuron (flSMN) mRNA. The secondary outcome measures were Modified Hammersmith Functional Motor Scale and forced vital capacity (FVC). Results: Fifty-five patients completed this trial, which lasted from March 2007 to June 2009. Except for neutropenia, we found no differences in adverse events between the 2 groups. Compared with the placebo group, the HU group had −1.88 for GMFM (p = 0.11), −0.55 for MMT (p = 0.49), and 2.17 for flSMN mRNA (p = 0.13). Similarly, we found no difference in mean improvement of the secondary endpoints. Both groups had a trend toward a decline in FVC with little change in strength and motor function. Conclusion: Under the current regimen and schedule, HU brought about no improvement in patients with type 2 and 3 SMA, and its main side effect was neutropenia. Classification of evidence: This trial provides Class I evidence that HU 20 mg/kg/day does not effectively treat SMA.

To study presentations and outcome of posterior reversible encephalopathy syndrome in children, we retrospectively analyzed 14 patients admitted to our pediatric intensive care unit. We further assessed 94 additional pediatric cases from a systematic review. Our patients had a mean age of 11.6 years. Their precipitating factors were hypertension (100%), immunosuppressants (71%), antineoplastic agents (21%), and hemodialysis (14%). Initial neurologic manifestations included seizures (100%), mental change (100%), headache (79%), and visual disturbance (57%). After prompt diagnosis by magnetic resonance imaging (MRI) with intensive management, all patients had complete clinical recovery with subsequent radiologic resolution. Systemic literature review indicated that seizures (90%), hypertension (85%), and atypical neuroimaging findings (80%) are common presentations in childhood posterior reversible encephalopathy syndrome. We conclude that in children presenting with seizures and hypertension, a pediatric neurologist should consider posterior reversible encephalopathy syndrome within a comprehensive differential diagnosis of acute encephalopathy. Early recognition and intensive care are essential to ensure complete neurologic recovery in children with posterior reversible encephalopathy syndrome.