Risk factors and outcome of hyponatremia in patients with Guillain-Barré syndrome.

The objective of the present study was to evaluate the risk factors and outcomes associated with hyponatremia in patients with Guillain-Barré syndrome (GBS). We retrospectively studied 80 consecutive patients with GBS who visited our hospital and compared clinical, laboratory, and electrophysiological findings of patients with and without hyponatremia. Disability was evaluated using the Hughes grading system. Of the 80 patients, 18 (23%) had hyponatremia. Hyponatremia was significantly associated with older age (P = 0.003), urinary retention (P < 0.0001), Hughes grade ≥ 4 at admission and nadir (P = 0.003 and P < 0.001, respectively), acute inflammatory demyelinating polyneuropathy subtype (P = 0.017), sepsis (P = 0.001), mechanical ventilator support (P = 0.013), longer hospitalization length of stay (P < 0.0001), and inability to walk independently at 6 months (P < 0.001). Multivariate analysis performed to assess the risk factors of hyponatremia revealed that urinary retention (odds ratio [OR] 30.7, 95% confidence interval [CI] 3.6-264.4; P = 0.002) and mechanical ventilator support (OR 13.8, 95% CI 1.6-118.0; P = 0.017) were significant independent risk factors of hyponatremia. In assessing the outcomes of patients with hyponatremia, multivariate analysis showed that hyponatremia was independently associated with hospitalization length of stay ≥ 60 days and inability to walk independently at 6 month, with the former showing statistical significance but the latter not (OR 9.3, 95% CI 1.8-47.7; P = 0.007 and OR 4.9, 95% CI 0.9-26.3; P = 0.066, respectively). Therefore, we demonstrate that, along with mechanical ventilator support, urinary retention-possibly indicating autonomic dysfunction-is a risk factor of hyponatremia in GBS. Moreover, we confirm that hyponatremia is associated with poor outcome in GBS.

Effects of selegiline on neuronal autophagy involving α-synuclein secretion.

Cell-to-cell transmission of α-synuclein (α-syn) pathology underlies the spread of neurodegeneration in Parkinson's disease. α-Syn secretion is an important factor in the transmission of α-syn pathology. However, it is unclear how α-syn secretion is therapeutically modulated. Here, we investigated effects of monoamine oxidase (MAO)-B inhibitor selegiline on α-syn secretion. Treatment with selegiline promoted α-syn secretion in mouse primary cortical neuron cultures, and this increase was kept under glial cell-eliminated condition by Ara-C. Selegiline-induced α-syn secretion was blocked by cytosolic Ca2+ chelator BAPTA-AM in primary neurons. Selegiline-induced α-syn secretion was retained in MAOA siRNA knockdown, whereas it was abrogated by ATG5 knockdown in SH-SY5Y cells. Selegiline increased LC3-II generation with a reduction in intracellular p62/SQSTM1 levels in primary neurons. The increase in LC3-II generation was blocked by co-treatment with BAPTA-AM in primary neurons. Additionally, fractionation experiments showed that selegiline-induced α-syn secretion occurred in non-extracellular vesicle fractions of primary neurons and SH-SY5Y cells. Collectively, these findings show that selegiline promotes neuronal autophagy involving secretion of non-exosomal α-syn via a change of cytosolic Ca2+ levels.

Neuronal activity promotes secretory autophagy for the extracellular release of α-synuclein.

Extracellular secretion is an essential mechanism for α-synuclein (α-syn) proteostasis. Although it has been reported that neuronal activity affects α-syn secretion, the underlying mechanisms remain unclear. Here, we investigated the autophagic processes that regulate the physiological release of α-syn in mouse primary cortical neurons and SH-SY5Y cells. Stimulating neuronal activity with glutamate or depolarization with high KCl enhanced α-syn secretion. This glutamate-induced α-syn secretion was blocked by a mixture of NMDA receptor antagonist AP5 and AMPA receptor antagonist NBQX, as well as by cytosolic Ca2+ chelator BAPTA-AM. Additionally, mTOR inhibitor rapamycin increased α-syn and p62/SQSTM1 (p62) secretion, and this effect of rapamycin was reduced in primary cortical neurons deficient in the autophagy regulator beclin 1 (derived from BECN1+/- mice). Glutamate-induced α-syn and p62 secretion was suppressed by the knockdown of ATG5, which is required for autophagosome formation. Glutamate increased LC3-II generation and decreased intracellular p62 levels, and the increase in LC3-II levels was blocked by BAPTA-AM. Moreover, glutamate promoted co-localization of α-syn with LC3-positive puncta, but not with LAMP1-positive structures in the neuronal somas. Glutamate-induced α-syn and p62 secretion were also reduced by the knockdown of RAB8A, which is required for autophagosome fusion with the plasma membrane. Collectively, these findings suggest that stimulating neuronal activity mediates autophagic α-syn secretion in a cytosolic Ca2+-dependent manner, and autophagosomes may participate in autophagic secretion by functioning as α-syn carriers.

[A pedigree of myotonia congenita with a novel mutation p.F343C of the CLCN1 gene].

A Japanese woman experienced slowness of movement in her early teens and difficulty in opening her hands during pregnancy. On admission to our hospital at 42 years of age, she showed grip myotonia with warm-up phenomenon. However, she had neither muscle weakness, muscle atrophy, cold-induced symptomatic worsening nor episodes of transient weakness of the extremities. Needle electromyography of the first dorsal interosseous and anterior tibial muscles demonstrated myotonic discharges. Whole exome sequencing of the patient revealed a heterozygous single-base substitution in the CLCN1 gene (c.1028T>G, p.F343C). The same substitution was identified in affected members of her family (mother and brother) by Sanger sequencing, but not in healthy family members (father and a different brother). We diagnosed myotonia congenita (Thomsen disease) with a novel CLCN1 mutation in this pedigree. This mutation causes a single amino acid substitution in the I-J extracellular loop region of CLCN1. Amino acid changes in the I-J loop region are rare in an autosomal-dominantly inherited form of myotonia congenita. We think that this pedigree is precious to understand the pathogenesis of myotonia congenita.

Spatial Fluctuation of Central Nervous System Lesions in X-linked Charcot-Marie-Tooth Disease with a Novel GJB1 Mutation.

X-linked Charcot-Marie-Tooth disease type 1 (CMTX1), the most common form of CMTX, is caused by gap-junction beta 1 (GJB1) mutations. We herein report a 25-year-old Japanese man with disorientation, right hemiparesis, and dysarthria. Brain magnetic resonance imaging (MRI) showed high signal intensities in the bilateral cerebral white matter on diffusion-weighted imaging. He had experienced 2 episodes of transient central nervous system symptoms (at 7 and 13 years old). A genetic analysis identified a novel GJB1 mutation, c.169C>T, p.Gln57*. MRI abnormalities shifted from the cerebral white matter to the corpus callosum and had disappeared at the five-month follow-up. Transient changes between these lesions may indicate CMTX1.

[A case of anti-myelin oligodendrocyte glycoprotein antibody-positive multiphasic disseminated encephalomyelitis showing significant recovery after immunoadsorption plasmapheresis].

The patient is an 18-year-old female. She had a history of acute disseminated encephalomyelitis at the age of 6 and 7. She visited our hospital due to acute disturbance of consciousness, quadriplegia, and numbness of left upper and lower extremities. Brain MRI showed multiple DWI/FLAIR high-signal lesions in the bilateral cerebral hemispheres, cerebellum, and brainstem. Qualitative test indicated that serum anti-MOG antibodies was positive, and she was diagnosed with anti-MOG antibody-positive polyphasic disseminated encephalomyelitis. Intravenous mPSL pulse therapy was performed twice, but the symptoms worsened. As a second line treatment, plasma exchange was started. However, she developed transfusion related acute lung injury. Alternatively, she was treated with immunoadsorption plasmapheresis. Her symptoms were significantly improved. This case seems to be valuable because there are few reports showing effectiveness of immunoadsorption therapy on anti-MOG antibody-related diseases, especially for polyphasic disseminated encephalomyelitis.

Clinical characteristics of long-term survival with noninvasive ventilation and factors affecting the transition to invasive ventilation in amyotrophic lateral sclerosis.

INTRODUCTION: We evaluated post-noninvasive ventilation survival and factors for the transition to tracheostomy in amyotrophic lateral sclerosis (ALS). METHODS: We analyzed 197 patients using a prospectively collected database with 114 patients since 2000. RESULTS: Among 114 patients, 59 patients underwent noninvasive ventilation (NIV), which prolonged the total median survival time to 43 months compared with 32 months without treatment. The best post-NIV survival was associated with a lack of bulbar symptoms, higher measured pulmonary function, and a slower rate of progression at diagnosis. The transition rate from NIV to tracheostomy gradually decreased over the years. Patients using NIV for more than 6 months were more likely to refuse tracheostomy and to be women. DISCUSSION: This study confirmed a positive survival effect with NIV, which was less effective in patients with bulbar dysfunction. Additional studies are required to determine the best timing for using NIV with ALS in patients with bulbar dysfunction. Muscle Nerve 58:770-776 2018.