Patisiran, an RNAi therapeutic for hereditary transthyretin-mediated amyloidosis: Sub-analysis in Taiwanese patients from the APOLLO study.

BACKGROUND AND OBJECTIVES: To examine the efficacy and safety of patisiran, an RNA interference therapeutic, in patients from Taiwan with hereditary transthyretin-mediated (hATTR) amyloidosis with polyneuropathy. METHODS: The APOLLO phase 3 trial included patients from Taiwan who received patisiran 0.3 mg/kg intravenously or placebo once every 3 weeks (q3w) for 18 months (18 M), followed by patisiran 0.3 mg/kg q3w in an ongoing global open-label extension (OLE) study. The primary endpoint was change from baseline in modified Neuropathy Impairment Score +7 (mNIS+7) at 18 M. RESULTS: Eighteen Taiwanese patients were enrolled in APOLLO (patisiran, n = 8; placebo, n = 10; all A97S gene variant) and 14 continued in the global OLE. In this Taiwanese sub-population, beneficial treatment effects at 18 M were observed in mNIS+7 (least squares mean difference in change from baseline [patisiran-placebo], -26.5 points; 95% confidence interval: -45.5, -7.5). Patients who switched from placebo to patisiran demonstrated slowing of polyneuropathy progression at month 12 in the global OLE, while those who received patisiran in APOLLO maintained the beneficial treatment effects. Patisiran had an acceptable safety profile in the Taiwanese sub-population. CONCLUSIONS: This analysis suggests that patisiran is well tolerated and may provide a substantial clinical benefit for Taiwanese patients with hATTR amyloidosis with polyneuropathy. TRIAL REGISTRATION INFORMATION: The studies were registered on the ClinicalTrials.gov. The APOLLO study ClinicalTrials.gov identifier is NCT01960348 (https://clinicaltrials.gov/ct2/show/NCT01960348), with the registration date of October 10, 2013, and the first patient was enrolled on December 13, 2013. For the global OLE, the ClinicalTrials.gov identifier is NCT02510261 (https://clinicaltrials.gov/ct2/show/NCT02510261) with the registration date of July 29, 2015, and the first patient was enrolled on July 13, 2015. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that treatment with patisiran is safe and efficacious in Taiwanese patients with hereditary transthyretin-mediated amyloidosis with polyneuropathy.

Clinical and genetic characterization of NEFL-related neuropathy in Taiwan.

BACKGROUND: Mutations in the neurofilament light polypeptide gene (NEFL) are an uncommon cause of Charcot-Marie-Tooth disease (CMT). The aim of this study is to elucidate the clinical characteristics and genetic spectrum of NEFL-related neuropathy in a Taiwanese CMT cohort. METHODS: Mutational analysis of the coding regions of NEFL was performed by Sanger sequencing or targeted resequencing. Twenty-one patients from nine CMT pedigrees, identified from a cohort of 508 unrelated CMT patients, were found to have a NEFL mutation. Genetic, clinical and electrophysiological features were analyzed. RESULTS: Six NEFL mutations were identified, including two novel ones (p.P8S, p.N98Y). NEFL p.E396K was the most common mutation, accounting for 33.3% of the patients in our cohort. All patients manifested sensorimotor polyneuropathy with a mean age of disease onset of 13.5 ± 9.6 (1-40) years. Their motor nerve conduction velocities (MNCVs) of the ulnar nerve ranged from 22.1 to 48.7 m/s. Seventy percent of the patients could be classified as intermediate CMT with ulnar MNCVs between 25 and 45 m/s. Six of the 21 patients (28.6%) had additional features of central nervous system (CNS) involvement, including motor developmental delay, spasticity, cerebellar signs, neuropathic pain and scoliosis. CONCLUSION: NEFL mutations account for 1.8% (9/508) of the CMT patients in Taiwan. The present study delineates the clinical and genetic characteristics of NEFL-related neuropathy in Taiwan, and highlights that ulnar MNCV above 25 m/s and CNS involvement may serve as diagnostic clues for NEFL-related neuropathy.

Treatment response, risk of relapse and clinical characteristics of Taiwanese patients with neuromyelitis optica spectrum disorder.

BACKGROUND/PURPOSE: The long-term disease course and efficacy of maintenance therapies have rarely been investigated in Asian patients with neuromyelitis optica spectrum disorder (NMOSD). METHODS: Medical records of patients fulfilling the 2015 International Consensus Diagnostic Criteria for NMOSD at three medical centers in Taiwan were systematically analyzed. Linear regression analysis was performed to investigate factors related to annualized relapse rate (ARR); survival analysis was used to estimate the relapse-free intervals among therapies. RESULTS: A total of 557 relapses affecting 648 regions (202 optic neuritis, 352 acute myelitis, and 94 brain syndromes) in 204 patients were analyzed during a follow-up period of 69.5 months (range, 1-420). Up to 36.1% of myelitis-onset patients and 24.0% of optic neuritis-onset patients exhibited a limited form disease, defined as having one or more relapses confined to the same region. The median ARR was significantly lower in patients with limited form disease than those with relapses involving multiple regions (0.30 vs. 0.47, respectively). An older age at disease onset was associated with a lower ARR (p = 0.023). Kaplan-Meier analysis showed that the estimated time (months) to next relapse was longest in rituximab-treatment group (58.0 ± 13.2), followed by immunosuppressant (48.5 ± 4.8) or prednisone (29.6 ± 4.6) groups, and shortest in those without maintenance therapy (27.6 ± 4.2) (p = 8.1 × 10-7). CONCLUSION: Limited form disease and older age at disease onset are associated with a lower relapse rate in NMOSD. Compared to no maintenance therapy, rituximab and immunosuppressant significantly reduce the relapse risks.

Patisiran, an RNAi Therapeutic, for Hereditary Transthyretin Amyloidosis.

BACKGROUND: Patisiran, an investigational RNA interference therapeutic agent, specifically inhibits hepatic synthesis of transthyretin. METHODS: In this phase 3 trial, we randomly assigned patients with hereditary transthyretin amyloidosis with polyneuropathy, in a 2:1 ratio, to receive intravenous patisiran (0.3 mg per kilogram of body weight) or placebo once every 3 weeks. The primary end point was the change from baseline in the modified Neuropathy Impairment Score+7 (mNIS+7; range, 0 to 304, with higher scores indicating more impairment) at 18 months. Other assessments included the Norfolk Quality of Life-Diabetic Neuropathy (Norfolk QOL-DN) questionnaire (range, -4 to 136, with higher scores indicating worse quality of life), 10-m walk test (with gait speed measured in meters per second), and modified body-mass index (modified BMI, defined as [weight in kilograms divided by square of height in meters]×albumin level in grams per liter; lower values indicated worse nutritional status). RESULTS: A total of 225 patients underwent randomization (148 to the patisiran group and 77 to the placebo group). The mean (±SD) mNIS+7 at baseline was 80.9±41.5 in the patisiran group and 74.6±37.0 in the placebo group; the least-squares mean (±SE) change from baseline was -6.0±1.7 versus 28.0±2.6 (difference, -34.0 points; P<0.001) at 18 months. The mean (±SD) baseline Norfolk QOL-DN score was 59.6±28.2 in the patisiran group and 55.5±24.3 in the placebo group; the least-squares mean (±SE) change from baseline was -6.7±1.8 versus 14.4±2.7 (difference, -21.1 points; P<0.001) at 18 months. Patisiran also showed an effect on gait speed and modified BMI. At 18 months, the least-squares mean change from baseline in gait speed was 0.08±0.02 m per second with patisiran versus -0.24±0.04 m per second with placebo (difference, 0.31 m per second; P<0.001), and the least-squares mean change from baseline in the modified BMI was -3.7±9.6 versus -119.4±14.5 (difference, 115.7; P<0.001). Approximately 20% of the patients who received patisiran and 10% of those who received placebo had mild or moderate infusion-related reactions; the overall incidence and types of adverse events were similar in the two groups. CONCLUSIONS: In this trial, patisiran improved multiple clinical manifestations of hereditary transthyretin amyloidosis. (Funded by Alnylam Pharmaceuticals; APOLLO ClinicalTrials.gov number, NCT01960348 .).

Cellular secretion and cytotoxicity of transthyretin mutant proteins underlie late-onset amyloidosis and neurodegeneration.

Transthyretin amyloidosis (ATTR) is a progressive life-threatening disease characterized by the deposition of transthyretin (TTR) amyloid fibrils. Several pathogenic variants have been shown to destabilize TTR tetramers, leading to aggregation of misfolded TTR fibrils. However, factors that underlie the differential age of disease onset amongst amyloidogenic TTR variants remain elusive. Here, we examined the biological properties of various TTR mutations and found that the cellular secretory pattern of the wild-type (WT) TTR was similar to those of the late-onset mutant (Ala97Ser, p. Ala117Ser), stable mutant (Thr119Met, p. Thr139Met), early-onset mutant (Val30Met, p. Val50Met), but not in the unstable mutant (Asp18Gly, p. Asp38Gly). Cytotoxicity assays revealed their toxicities in the order of Val30Met > Ala97Ser > WT > Thr119Met in neuroblastoma cells. Surprisingly, while early-onset amyloidogenic TTR monomers (M-TTRs) are retained by the endoplasmic reticulum quality control (ERQC), late-onset amyloidogenic M-TTRs can be secreted extracellularly. Treatment of thapsigargin (Tg) to activate the unfolded protein response (UPR) alleviates Ala97Ser M-TTR secretion. Interestingly, Ala97Ser TTR overexpression in Drosophila causes late-onset fast neurodegeneration and a relatively short lifespan, recapitulating human disease progression. Our study demonstrates that the escape of TTR monomers from the ERQC may underlie late-onset amyloidogenesis in patients and suggests that targeting ERQC could mitigate late-onset ATTR.

Comparison of Corticosteroid Injection Dosages in Mild to Moderate Idiopathic Carpal Tunnel Syndrome: A Randomized Controlled Trial.

OBJECTIVES: To evaluate whether the therapeutic effect of ultrasound-guided injections with 10 mg or 40 mg triamcinolone acetonide (TA) was dose-dependent in patients with idiopathic mild to moderate carpal tunnel syndrome (CTS). DESIGN: Prospective, double-blind, randomized controlled study with 12 weeks of follow-up. SETTING: Rehabilitation outpatient clinic of a single medical center. PARTICIPANTS: Patients with CTS (N=56). INTERVENTION: Participants were randomly assigned to 2 treatment groups for injection: (A) 40 mg TA+2% lidocaine hydrochloride or (B) 10 mg TA+2% lidocaine hydrochloride. MAIN OUTCOME MEASURES: Participants were evaluated using visual analog scale (VAS) and Boston Carpal Tunnel Questionnaire (BCTQ, including Symptom Severity Scale [SSS] and Functional Status Scale [FSS]) at baseline and 6 and 12 weeks after injection). Nerve conduction studies, including parameters of distal motor latency, amplitude of compound motor action potential, amplitude of sensory nerve action potential and sensory nerve conduction velocity of median nerve, and the patient's subjective impression of improvement, were recorded before injection and 6 and 12 weeks after injection. RESULTS: No significant differences were observed in baseline demographic characteristics and clinical evaluations. The parameters in group A and B at baseline, 6 weeks, and 12 weeks were (1) SSS: 2.17±0.14, 1.19±0.04, and 1.34±0.09 and 1.87±0.11, 1.21±0.07, and 1.26±0.04; (2) FSS: 1.63±0.07, 1.27±0.06, and 1.33±0.08 and 1.50±0.10, 1.18±0.05, and 1.26±0.05; (3) VAS: 6.4±0.3, 2.2±0.3, and 3.0±0.1 and 6.7±0.3, 2.0±0.3, and 3.1±0.3, respectively, and significantly decreased after 6 and 12 weeks in both treatment groups (P<.05). All parameters of nerve conduction studies improved in both groups after 12 weeks (P<.05). VAS, BCTQ, and nerve conduction studies did not show significant intergroup differences after 6 and 12 weeks. CONCLUSION: In patients with idiopathic mild to moderate CTS, ultrasound-guided injection with 10 and 40 mg TA yield similar improvements in BCTQ, VAS, and nerve conduction studies at the 12-week follow-up.

Sonographic median nerve change after steroid injection for carpal tunnel syndrome.

INTRODUCTION: The sonographic changes of the median nerve after steroid injection for carpal tunnel syndrome (CTS) still require investigation. METHODS: Sixty-two patients with CTS were included. The Boston Carpal Tunnel Questionnaire was administered, and ultrasonographic examinations were performed before and at 2, 6, and 12 weeks after steroid injection. At 12 weeks, general improvement was scored on a 6-point Likert scale. RESULTS: After treatment, the cross-sectional area (CSA) of the median nerve was significantly reduced at 2-, 6-, and 12-week follow-ups (for each, P < 0.001, analysis of variance). The "significant improvement" group (n = 39) had a significantly greater reduction in the CSA at the carpal tunnel inlet (P = 0.014) and CSA in the proximal carpal tunnel (P = 0.003) compared with the "little/no improvement" group (n = 23). DISCUSSION: Sonographic measurement of CSA may be considered complementary to the standard clinical evaluation in monitoring of treatment response in patients with CTS. Muscle Nerve 58: 402-406, 2018.

A recurrent WARS mutation is a novel cause of autosomal dominant distal hereditary motor neuropathy.

Distal hereditary motor neuropathy is a heterogeneous group of inherited neuropathies characterized by distal limb muscle weakness and atrophy. Although at least 15 genes have been implicated in distal hereditary motor neuropathy, the genetic causes remain elusive in many families. To identify an additional causal gene for distal hereditary motor neuropathy, we performed exome sequencing for two affected individuals and two unaffected members in a Taiwanese family with an autosomal dominant distal hereditary motor neuropathy in which mutations in common distal hereditary motor neuropathy-implicated genes had been excluded. The exome sequencing revealed a heterozygous mutation, c.770A > G (p.His257Arg), in the cytoplasmic tryptophanyl-tRNA synthetase (TrpRS) gene (WARS) that co-segregates with the neuropathy in the family. Further analyses of WARS in an additional 79 Taiwanese pedigrees with inherited neuropathies and 163 index cases from Australian, European, and Korean distal hereditary motor neuropathy families identified the same mutation in another Taiwanese distal hereditary motor neuropathy pedigree with different ancestries and one additional Belgian distal hereditary motor neuropathy family of Caucasian origin. Cell transfection studies demonstrated a dominant-negative effect of the p.His257Arg mutation on aminoacylation activity of TrpRS, which subsequently compromised protein synthesis and reduced cell viability. His257Arg TrpRS also inhibited neurite outgrowth and led to neurite degeneration in the neuronal cell lines and rat motor neurons. Further in vitro analyses showed that the WARS mutation could potentiate the angiostatic activities of TrpRS by enhancing its interaction with vascular endothelial-cadherin. Taken together, these findings establish WARS as a gene whose mutations may cause distal hereditary motor neuropathy and alter canonical and non-canonical functions of TrpRS.

Acute Sensory Neuronopathy following Enterovirus Infection in a 3-Year-Old Girl.

Acute sensory neuronopathy (SNN) is a rapidly developing peripheral nervous system disease that primarily affects sensory neurons in the dorsal root ganglion or trigeminal ganglion, leading to the impairment of sensory axons. SNN is notably uncommon in childhood; only three cases of childhood or adolescent SNN have been reported to date. Moreover, SSN has never been reported in association with enterovirus infection. Here, we report the case of a 3-year-old girl who was initially diagnosed with enterovirus infection based on the presentation of fevers, rashes on all extremities, and ulceration over the posterior pharynx. Nine days later, she presented with ataxic and wide-based gait and dysmetria affecting the extremities, with an absence of sensory nerve action potentials in the upper and lower limbs. The patient was diagnosed with acute SNN based on the criteria developed by Camdessanché et al in 2009. To our knowledge, this is the youngest case of SNN reported to date. In addition, this case reveals that enterovirus infection can be associated with acute SNN in children in rare cases. Accurate diagnosis relies on clinical suspicion, comprehensive knowledge of the patient's history, and careful characterization of abnormal findings in electrodiagnostic studies.

Efficacy of Combined Ultrasound-Guided Steroid Injection and Splinting in Patients With Carpal Tunnel Syndrome: A Randomized Controlled Trial.

OBJECTIVE: To compare the effectiveness of local steroid injection plus splinting with that of local steroid injection alone using clinical and electrophysiological parameters in patients with carpal tunnel syndrome (CTS). DESIGN: Randomized controlled study with 12 weeks of follow-up. SETTING: Tertiary care center. PARTICIPANTS: Volunteer sample of patients (N=52) diagnosed with CTS. INTERVENTIONS: Participants were randomly assigned to the steroid injection group (n=26) or the steroid injection-plus-splinting group (n=26). Patients of both groups received ultrasound-guided steroid injection with 1mL of 10mg (10mg/mL) triamcinolone acetonide (Shincort) and 1mL of 2% lidocaine hydrochloride (Xylocaine). Participants in the second group also wore a volar splint in the neutral position while sleeping and also during daytime whenever possible for the 12-week intervention period. MAIN OUTCOME MEASURES: Participants were evaluated before the treatment and at 6 and 12 weeks after the onset of treatment. The primary outcome measure was Boston Carpal Tunnel Questionnaire scores. The secondary outcome measures were as follows: scores on the visual analog scale for pain; electrophysiological parameters, including median nerve distal motor latency, sensory nerve conduction velocity (SNCV), and compound muscle action potential and sensory nerve action potential (SNAP) amplitudes; and patient's subjective impression of improvement. RESULTS: At 12-week follow-up, improvements in symptom severity and functional status scores on the Boston Carpal Tunnel Questionnaire as well as SNCV and SNAP amplitudes were greater in the group that received steroid injection combined with splinting than in the group that received steroid injection alone. The between-group difference was .48 points (95% confidence interval [CI], .09-.88 points; P=.032) in the Symptom Severity Scale score, .37 points (95% CI, .06-.67 points; P=.019) in the Functional Status Scale score, 3.38m/s (95% CI, 0.54-6.22m/s; P=.015) in the SNCV amplitude, and 3.21µV (95% CI, 0.00-6.46µV; P=.025) in the SNAP amplitude. CONCLUSIONS: In people with CTS, steroid injection combined with splinting resulted in modestly greater reduction of symptoms, superior functional recovery, and greater improvement in nerve function at 12-week follow-up as compared with steroid injection alone. However, these small differences are of unclear clinical significance.

Exome sequencing identifies GNB4 mutations as a cause of dominant intermediate Charcot-Marie-Tooth disease.

Charcot-Marie-Tooth disease (CMT) is a heterogeneous group of inherited neuropathies. Mutations in approximately 45 genes have been identified as being associated with CMT. Nevertheless, the genetic etiologies of at least 30% of CMTs have yet to be elucidated. Using a genome-wide linkage study, we previously mapped a dominant intermediate CMT to chromosomal region 3q28-q29. Subsequent exome sequencing of two affected first cousins revealed heterozygous mutation c.158G>A (p.Gly53Asp) in GNB4, encoding guanine-nucleotide-binding protein subunit beta-4 (Gß4), to cosegregate with the CMT phenotype in the family. Further analysis of GNB4 in an additional 88 unrelated CMT individuals uncovered another de novo mutation, c.265A>G (p.Lys89Glu), in this gene in one individual. Immunohistochemistry studies revealed that Gß4 was abundant in the axons and Schwann cells of peripheral nerves and that expression of Gß4 was significantly reduced in the sural nerve of the two individuals carrying the c.158G>A (p.Gly53Asp) mutation. In vitro studies demonstrated that both the p.Gly53Asp and p.Lys89Glu altered proteins impaired bradykinin-induced G-protein-coupled-receptor (GPCR) signaling, which was facilitated by the wild-type Gß4. This study identifies GNB4 mutations as a cause of CMT and highlights the importance of Gß4-related GPCR signaling in peripheral-nerve function in humans.

Reduced-penetrance Huntington's disease-causing alleles with 39 CAG trinucleotide repeats could be a genetic factor of amyotrophic lateral sclerosis.

BACKGROUND: Expanded HTT alleles with 40 or more CAG repeats were recently found to be a rare cause of frontotemporal dementia and amyotrophic lateral sclerosis (ALS) spectrum diseases. The aim of this study was to investigate the role of HTT repeat expansions in a Taiwanese cohort with ALS. METHODS: We analyzed the numbers of CAG repeats in exon 1 of HTT in a cohort of 410 Taiwanese patients with ALS and 1514 control individuals by utilizing polymerase chain reaction and amplicon fragment length analysis. RESULTS: Only one of the 410 ALS patients carried a reduced-penetrance HD-causing allele with 39 CAG repeats, and none had an expanded HTT CAG repeats ≥40. The patient presented with rapidly progressive bulbar-onset ALS with disease onset at the age of 64 years. He had neither chorea nor cognitive impairment. He had a family history of chorea, but no other family member manifested with ALS. None of the 1514 control individuals carried an HTT expanded allele with CAG repeats larger than 37 repeats. CONCLUSION: The HTT allele with 39 CAG repeats could be a genetic factor linked to ALS susceptibility.

Impact of Vutrisiran on Quality of Life and Physical Function in Patients with Hereditary Transthyretin-Mediated Amyloidosis with Polyneuropathy.

INTRODUCTION: Hereditary transthyretin (ATTRv; v for variant) amyloidosis, also known as hATTR amyloidosis, is a progressive and fatal disease associated with rapid deterioration of physical function and patients' quality of life (QOL). Vutrisiran, a subcutaneously administered RNA interference (RNAi) therapeutic that reduces hepatic production of transthyretin, was assessed in patients with ATTRv amyloidosis with polyneuropathy in the pivotal HELIOS-A study. METHODS: The phase 3 open-label HELIOS-A study investigated the efficacy and safety of vutrisiran in patients with ATTRv amyloidosis with polyneuropathy, compared with an external placebo group from the APOLLO study of the RNAi therapeutic patisiran. Measures of QOL and physical function were assessed. RESULTS: At month 18, vutrisiran improved Norfolk Quality of Life-Diabetic Neuropathy (Norfolk QOL-DN) total score (least squares mean difference [LSMD] in change from baseline [CFB]: -21.0; p = 1.84 × 10-10) and Norfolk QOL-DN domain scores, compared with external placebo. This benefit relative to external placebo was evident across all baseline polyneuropathy disability (PND) scores and most pronounced in patients with baseline PND scores I-II. Compared with external placebo, vutrisiran also demonstrated benefit in EuroQoL-Visual Analog Scale (EQ-VAS) score (LSMD in CFB: 13.7; nominal p = 2.21 × 10-7), 10-m walk test (LSMD in CFB: 0.239 m/s; p = 1.21 × 10-7), Rasch-built Overall Disability Score (LSMD in CFB: 8.4; p = 3.54 × 10-15), and modified body mass index (mBMI) (LSMD in CFB: 140.7; p = 4.16 × 10-15) at month 18. Overall, Norfolk QOL-DN, EQ-VAS, and mBMI improved from pretreatment baseline with vutrisiran, whereas all measures worsened from baseline in the external placebo group. At month 18, Karnofsky Performance Status was stable/improved from baseline in 58.2/13.1% with vutrisiran versus 34.7/8.1% with external placebo. CONCLUSION: Vutrisiran treatment provided significant clinical benefits in multiple measures of QOL and physical function in patients with ATTRv amyloidosis with polyneuropathy. Benefits were most pronounced in patients with earlier-stage disease, highlighting the importance of early diagnosis and treatment. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov: NCT03759379.

"Effect of transcranial magnetic stimulation to motor cortex on pain perception and nociceptive reflex".

"Noxious stimulation over the foot can evoke a nociceptive flexor reflex (NR) in the lower limb especially for tibialis anterior muscle (TA). Components of NR include the monosynaptic fast latency NRII, and the polysynaptic slow latency NRIII, supposedly a spinal segmental reflex influenced by the supraspinal control. Pain perception is quantified by visual analogous scale (VAS) and has been reported to be related to NRIII. Previous papers have reported the long lasting effect of transcranial magnetic stimulation (TMS), as well as TMS suppressing pain perception. The purpose of this study was to investigate the immediate and prolonged effect of a single-pulse TMS to suppress NR and pain. NRIII was provoked at right TA by a train of electrical stimulation on the right toe in 10 healthy subjects. TMS was delivered over the vertex area to evoke right anterior tibialis muscle activity. A sham TMS from different directions of the coil was performed on the next day. The NRIII amplitude and VAS were measured. As a result, the amplitude of NRIII was significantly decreased than the control 50 ms pre-stimulation (0.20 ± 0.13 mA vs . 0.65 ± 0.42 mV, P = 0.016), 100 ms pre-stimulation (0.10 ± 0.10 mA vs . 0.65 ± 0.42 mV, P = 0.001), 15 min post-stimulation (0.12 ± 0.09 mA vs . 0.65 ± 0.42 mV, P = 0.004), and 30 min post-stimulation (0.41 ± 0.21 mA vs . 0.65 ± 0.42 mV, P = 0.046). VAS was diminished compared with the control 50 ms pre-stimulation (3.3 ± 0.9 vs . 5.4 ± 1.3, P = 0.002), 100 ms pre-stimulation (2.6 ± 0.5 vs . 5.4 ± 1.3, P < 0.001) and 15 min post-stimulation (3.5 ± 0.9 vs . 5.4 ± 1.3, P = 0.046). The NRIII amplitude was well correlated with VAS in reduction during the TMS condition and 15 min after electrical stimulation (P < 0.001). The sham TMS did not suppress NRIII or VAS. In conclusion, our results indicate that NRIII and the nociception can be inhibited by one single pulse TMS and such an effect can last for a period of time."

Assessing the NOTCH2NLC GGC repeat expansion in Taiwanese patients with hereditary spastic paraplegia.

We investigated 98 Taiwanese patients with molecularly unassigned hereditary spastic paraplegia (HSP) and found none of them had the NOTCH2NLC GGC repeat expansion, which is the cause of neuronal intranuclear inclusion disease (NIID). Our findings suggest that the NOTCH2NLC GGC repeat expansion may not contribute to HSP.

Investigating KIF1A mutations in a Taiwanese cohort with hereditary spastic paraplegia.

BACKGROUND: Hereditary spastic paraplegia (HSP) is a heterogeneous group of inherited neurodegenerative disorders characterized by slowly progressive lower limbs spasticity and weakness. HSP type 30 (SPG30) is a HSP subtype caused by mutations in the kinesin family member 1A gene (KIF1A) and could be either autosomal dominantly or recessively inherited. The aim of this study was to investigate the clinical and genetic features of KIF1A mutations in a Taiwanese HSP cohort. METHODS: Mutational analysis of KIF1A was performed in 242 unrelated Taiwanese patients of Han Chinese ethnicity with clinically suspected HSP using targeted resequencing panel covering the entire coding regions of KIF1A. Clinical, electrophysiological and neuroimaging features of the HSP patients carrying a KIF1A mutation were characterized. RESULTS: Three different KIF1A mutations were identified in three patients with autosomal dominantly inherited HSP. Among them, KIF1A p.E19K was a novel mutation. The patient harboring KIF1A p.G321D presented with pure HSP, while the individuals carrying KIF1A p.E19K or p.R316Q manifested complex HSP with additional axonal sensorimotor polyneuropathy. The patients carrying KIF1A p.R316Q also had thoracic cord atrophy, thin corpus callosum and white matter hyperintensity. CONCLUSION: SPG30 accounts for 1.2% (3/242) of patients in the Taiwanese HSP cohort, suggesting that it is an uncommon HSP subtype in Taiwan. This study delineates the clinical and genetic features of SPG30 in Taiwan and provides useful information for the diagnosis and management of SPG30, especially in patients of Han Chinese descent.

GGC Repeat Expansion of NOTCH2NLC in Taiwanese Patients With Inherited Neuropathies.

BACKGROUND AND OBJECTIVES: The GGC repeat expansion in the 5' untranslated region of NOTCH2NLC was recently identified as the cause of neuronal intranuclear inclusion disease (NIID), which may manifest with peripheral neuropathy. The aim of this study is to investigate its contribution to inherited neuropathy. METHODS: This cohort study screened patients with molecularly undiagnosed Charcot-Marie-Tooth disease (CMT) and healthy controls for the GGC repeat expansion in NOTCH2NLC using repeat-primed PCR and fragment analysis. The clinical and electrophysiologic features of the patients harboring the GGC repeat expansion were scrutinized. Skin biopsy with immunohistochemistry staining and electric microscopic imaging were performed. RESULTS: One hundred twenty-seven unrelated patients with CMT, including 66 cases with axonal CMT (CMT2), and 200 healthy controls were included. Among them, 7 patients with CMT carried a variant NOTCH2NLC allele with GGC repeat expansion, but it was absent in controls. The sizes of the expanded GGC repeats ranged from 80 to 104 repeats. All 7 patients developed sensory predominant neuropathy with an average age at disease onset of 37.1 years (range 21-55 years). Electrophysiologic studies revealed mild axonal sensorimotor polyneuropathy. Leukoencephalopathy was absent in the 5 patients who received a brain MRI. Skin biopsy from 2 patients showed eosinophilic, ubiquitin- and p62-positive intranuclear inclusions in the sweat gland cells and dermal fibroblasts. Two of the 7 patients had a family history of NIID. DISCUSSION: The NOTCH2NLC GGC repeat expansions are an underdiagnosed and important cause of inherited neuropathy. The expansion accounts for 10.6% (7 of 66) of molecularly unassigned CMT2 cases in the Taiwanese CMT cohort. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that in Taiwanese patients with genetically undiagnosed CMT, 10.6% of the CMT2 cases have the GGC repeat expansion in NOTCH2NLC.

Comparison of cerebellar ataxias: A three-year prospective longitudinal assessment.

We quantitatively investigated the clinical severity and progression of diseases with ataxia, as measured with the Scale for the Assessment and Rating of Ataxia, and examined the potential application of the Scale for the Assessment and Rating of Ataxia for future therapeutic trials. Severity of ataxia was assessed in 238 patients with spinocerebellar ataxia type 2, spinocerebellar ataxia type 3, spinocerebellar ataxia type 6, spinocerebellar ataxia type 17, multiple system atrophy-cerebellar variant, or Gerstman-Sträussler-Scheinker disease. Among them, 119 (50%) were longitudinally examined three to seven times, in a period of 8 to 38 months, resulting in a total set of 535 assessments. The differences between spinocerebellar ataxia and multiple system atrophy-cerebellar variant were ascertained cross-sectionally and longitudinally. Gerstman-Sträussler-Scheinker disease had the fastest progression, followed by multiple system atrophy-cerebellar variant, spinocerebellar ataxia type 17, spinocerebellar ataxia type 3, spinocerebellar ataxia type 2, and spinocerebellar ataxia type 6. Patients with multiple system atrophy-cerebellar variant had a faster progression in gait, sitting, speech, and total score than patients with spinocerebellar ataxias. For a randomized, case-control trial, a sample size of 47 for spinocerebellar ataxia and 85 for multiple system atrophy-cerebellar variant in the treatment or placebo arms would have a sufficient statistical power to demonstrate the efficacy of a new therapy that would retard ataxia progression by 1 point per year as measured by the Scale for the Assessment and Rating of Ataxia. The results will have a significant impact on the planning and implementation of future therapeutic trials of spinocerebellar ataxia and multiple system atrophy-cerebellar variant.

Investigating TBP CAG/CAA trinucleotide repeat expansions in a Taiwanese cohort with ALS.

Intermediate-length CAG repeats in ATXN2 have been well recognized as a genetic risk factor for amyotrophic lateral sclerosis (ALS). However, the role of similar trinucleotide repeat expansions in the TATA-box binding protein gene (TBP), another disease-associated gene for inherited ataxia, in ALS remains elusive. To assess the association between TBP trinucleotide repeat expansions and ALS, we investigated the repeat lengths in 325 unrelated ALS patients and 1500 controls in the Taiwanese population. The most common size of repeats in the patients and controls were both 36. The repeat lengths ranged from 29 to 46 repeats in the ALS patients and 27 to 43 repeats in the controls. Two ALS patients carried a TBP allele with a repeat number equal or greater than 44 (44 and 46). The patient with the 46 trinucleotide repeats also had a C9ORF72 GGGGCC hexanucleotide repeat expansion. The odds ratio of an individual carrying the CAG/CAA repeats ≥ 44 to have ALS is 23.2 (95% confidence interval: 1.11-484.24; p = 0.04). Our findings suggest that intermediate-length CAG/CAA repeat expansions in TBP may associate with ALS risk.

Genetic and Functional Analysis of Glycosyltransferase 8 Domain-Containing Protein 1 in Taiwanese Patients With Amyotrophic Lateral Sclerosis.

BACKGROUND AND OBJECTIVES: To investigate the frequency, spectrum, and molecular functional effect of glycosyltransferase 8 domain-containing protein 1 (GLT8D1) variations in Taiwanese patients with amyotrophic lateral sclerosis (ALS). METHODS: We performed genetic analyses of GLT8D1 in 410 unrelated patients with ALS by Sanger sequencing. The 410 patients were selected from a cohort of 477 unrelated patients with ALS after excluding variations in common ALS disease genes. Functional effects of the GLT8D1 variation were investigated by in vitro functional analysis. RESULTS: We identified a novel heterozygous missense variation in GLT8D1, p.I290M (c.870C>G), in 1 single patient with familial ALS. The patient with the p.I290M variation had a spinal-onset ALS with disease onset at age 60 years and a survival of 6 years. Functional studies demonstrated that the variant I290M GLT8D1 protein was mislocalized to the endoplasmic reticulum (ER), provoked ER stress and unfolded protein response, compromised the glycosyltransferase activity, and led to an increased cytotoxicity. DISCUSSION: GLT8D1 variations account for 0.2% (1/477) of the patients with ALS in Taiwan. These findings expand the spectrum of GLT8D1 variation and support the pathogenic role of GLT8D1 variations in ALS.