Peripheral neuropathy and nerve electrophysiological changes with enfortumab vedotin in patients with advanced urothelial carcinoma: a prospective multicenter cohort study.

BACKGROUND: Enfortumab vedotin is a novel antibody-drug conjugate used as a third-line therapy for the treatment of urothelial cancer. We aimed to elucidate the effect of enfortumab vedotin-related peripheral neuropathy on its efficacy and whether enfortumab vedotin-induced early electrophysiological changes could be associated with peripheral neuropathy onset. METHODS: Our prospective multicenter cohort study enrolled 34 patients with prior platinum-containing chemotherapy and programmed cell death protein 1/ligand 1 inhibitor-resistant advanced urothelial carcinoma and received enfortumab vedotin. The best overall response, progression-free survival, overall survival, and safety were assessed. Nerve conduction studies were also performed in 11 patients. RESULTS: The confirmed overall response rate and disease control rate were 52.9% and 73.5%, respectively. The median overall progression-free survival and overall survival were 6.9 and 13.5 months, respectively, during a median follow-up of 8.6 months. The patients with disease control had significantly longer treatment continuation and overall survival than did those with uncontrolled disease. Peripheral neuropathy occurred in 12.5% of the patients. The overall response and disease control rates were 83.3% and 100%, respectively: higher than those in patients without peripheral neuropathy (p = 0.028 and p = 0.029, respectively). Nerve conduction studies indicated that enfortumab vedotin reduced nerve conduction velocity more markedly in sensory nerves than in motor nerves and the lower limbs than in the upper limbs, with the sural nerve being the most affected in the patients who developed peripheral neuropathy (p = 0.011). CONCLUSION: Our results indicated the importance of focusing on enfortumab vedotin-induced neuropathy of the sural nerve to maximize efficacy and improve safety.

Metabolites and Biomarker Compounds of Neurodegenerative Diseases in Cerebrospinal Fluid.

Despite recent advances in diagnostic procedures for neurological disorders, it is still difficult to definitively diagnose some neurodegenerative diseases without neuropathological examination of autopsied brain tissue. As pathological processes in the brain are frequently reflected in the components of cerebrospinal fluid (CSF), CSF samples are sometimes useful for diagnosis. After CSF is secreted from the choroid plexus epithelial cells in the ventricles, some flows in the brain, some is mixed with intracerebral interstitial fluid, and some is excreted through two major drainage pathways, i.e., the intravascular periarterial drainage pathway and the glymphatic system. Accordingly, substances produced by metabolic and pathological processes in the brain may be detectable in CSF. Many papers have reported changes in the concentration of substances in the CSF of patients with metabolic and neurological disorders, some of which can be useful biomarkers of the disorders. In this paper, we show the significance of glucose- and neurotransmitter-related CSF metabolites, considering their transporters in the choroid plexus; summarize the reported candidates of CSF biomarkers for neurodegenerative diseases, including amyloid-ß, tau, α-synuclein, microRNAs, and mitochondrial DNA; and evaluate their potential as efficient diagnostic tools.

A cerebrospinal fluid microRNA analysis: Progressive supranuclear palsy.

Progressive supranuclear palsy (PSP) is a neurodegenerative tauopathy described as a syndrome of postural instability, supranuclear vertical gaze palsy, dysarthria, dystonic rigidity of the neck and trunk, dementia, and pseudobulbar palsy. The clinical diagnosis of PSP is often difficult because there are no established biomarkers, and diagnosis is currently based on clinical and imaging findings. Furthermore, the etiology and pathogenesis of PSP remain unknown. Dysregulation of microRNAs (miRNAs/miRs) has been reported to serve an important role in neurodegenerative diseases. However, the miRNA profiles of patients with PSP are rarely reported. The present study aimed to examine cerebrospinal fluid miRNAs, which are considered to be more sensitive indicators of changes in the brain, to elucidate the pathophysiology of PSP and to establish specific biomarkers for diagnosis. The present study used a microarray chip containing 2,632 miRNAs to examine cerebrospinal fluid miRNA expression levels in 11 patients with PSP aged 68­82 years. A total of 8 age­ and sex­matched controls were also included. A total of 38 miRNAs were significantly upregulated and one miRNA was significantly downregulated in the cerebrospinal fluid of patients with PSP. The patients were divided into two groups based on disease stage (early onset and advanced), and changes in miRNA expression were examined. The miRNAs that were most significantly upregulated or downregulated in the early onset group were miR­204­3p, miR­873­3p and miR­6840­5p. The target genes of these miRNAs were associated with molecules related to the ubiquitin­proteasome system and autophagy pathway. Furthermore, these miRNAs were found to target genes that have been reported to have epigenetic changes following an epigenome­wide association study of brain tissues of patients with PSP. This suggested that these miRNAs and genes may have some involvement in the pathogenesis of PSP. However, the sample size of the present study was small; therefore, a greater number of patients with PSP should be examined in future studies.

Ascending spinal tract formation in chick embryo originating from different spinal regions.

The present study aimed to assess spinal tract formation in neurons originating from cervical (C7), brachial (C14), and thoracic (T4) regions, with the lumbar (LS2) region as a reference, in a chick embryo. For the assessment of the spinal tracts, we introduced a vector expressing human placental alkaline phosphatase into progenitor cells generated after neural tube closure and belonging to the above segments, using in ovo electroporation. The ascending axons took primarily similar paths: dorsal commissural, ventral commissural, and dorsal non-commissural paths, with some variance depending on their originating segments. Some populations of non-commissural neurons later extended their axons following a ventral path. The elongation rates of these axons are primarily constant and tended to increase over time; however, some variations depending on the originating segments were also observed. Some of the dorsally ascending axons entered into the developing cerebellum, and spinocerebellar neurons originating from T4 projected their axons into the cortex of the cerebellum differently from those from LS2. These results unveil an overall picture of early ascending spinal tract formation.

Analysis of genetic risk factors in Japanese patients with Parkinson's disease.

Parkinson's disease (PD) is caused by a combination of genetic and environmental factors. Notably, genetic risk factors vary according to ethnicity and geographical regions, and few studies have analyzed the frequency of PD causative genes in Japanese patients. Therefore, we performed genetic analyses of Japanese patients with PD. We recruited 221 participants, including 26 patients with familial PD. Genetic risk factors were evaluated by target sequencing and gene dosage analysis. We detected the genetic risk factors in 58 cases (26.2%) and classified patients into three groups to clarify the differences in genetic risk factors by age at onset (AAO). The early-onset group (AAO < 50 years) included 18 cases (44.7%), who tended to have a larger number of genetic risk factors than the later-onset groups. Regarding the AAO for each causative gene, patients with PRKN variants were significantly younger at onset than those bearing LRRK2 variants. LRRK2 variants showed similar frequency in each AAO group. Of note, we identified two novel variants. Patients with early-onset PD have more genetic risk factors than patients with late-onset PD. In Japanese patients with PD, PRKN, and LRRK2 were the major PD-related genes. Particularly, LRRK2 was a common genetic factor in all age groups because of the presence of the Asian-specific variant such as LRRK2 p.G2385R. Accumulation of genetic and clinical data can contribute to the development of treatments for PD.

Premedication of hemin for eradication therapy of Helicobacter pylori in patients with porphyria.

Eradication therapy of Helicobacter pylori may be safe if hemin has been intravenously administered in advance, even in patients with a history of recurrent acute porphyria attack.

Optineurin defects cause TDP43-pathology with autophagic vacuolar formation.

We previously showed that optineurin (OPTN) mutations lead to the development of amyotrophic lateral sclerosis. The association between OPTN mutations and the pathogenesis of amyotrophic lateral sclerosis remains unclear. To investigate the mechanism underlying its pathogenesis, we generated Optn knockout mice. We evaluated histopathological observations of these mice and compared with those of OPTN- amyotrophic lateral sclerosis cases to investigate the mechanism underlying the pathogenesis of amyotrophic lateral sclerosis caused by OPTN mutations. The Optn (-/-) mice presented neuronal autophagic vacuoles immunopositive for charged multivesicular body protein 2b, one of the hallmarks of granulovacuolar degenerations, in the cytoplasm of spinal cord motor neurons at the age of 8 months and the OPTN- amyotrophic lateral sclerosis case with homozygous Q398X mutation. In addition, Optn (-/-) mice showed TAR-DNA binding protein 43/sequestosome1/p62 -positive cytoplasmic inclusions and the clearance of nuclear TAR-DNA binding protein 43. The axonal degeneration of the sciatic nerves was observed in Optn (-/-) mice. However, we could not observe significant differences in survival time, body weight, and motor functions, at 24 months. Our findings suggest that homozygous OPTN deletion or mutations might result in autophagic dysfunction and TAR-DNA binding protein 43 mislocalization, thereby leading to neurodegeneration of motor neurons. These findings indicate that the Optn (-/-) mice recapitulate both common and specific pathogenesis of amyotrophic lateral sclerosis associated with autophagic abnormalities. Optn (-/-) mice could serve as a mouse model for the development of therapeutic strategies.

Glucose, Fructose, and Urate Transporters in the Choroid Plexus Epithelium.

The choroid plexus plays a central role in the regulation of the microenvironment of the central nervous system by secreting the majority of the cerebrospinal fluid and controlling its composition, despite that it only represents approximately 1% of the total brain weight. In addition to a variety of transporter and channel proteins for solutes and water, the choroid plexus epithelial cells are equipped with glucose, fructose, and urate transporters that are used as energy sources or antioxidative neuroprotective substrates. This review focuses on the recent advances in the understanding of the transporters of the SLC2A and SLC5A families (GLUT1, SGLT2, GLUT5, GLUT8, and GLUT9), as well as on the urate-transporting URAT1 and BCRP/ABCG2, which are expressed in choroid plexus epithelial cells. The glucose, fructose, and urate transporters repertoire in the choroid plexus epithelium share similar features with the renal proximal tubular epithelium, although some of these transporters exhibit inversely polarized submembrane localization. Since choroid plexus epithelial cells have high energy demands for proper functioning, a decline in the expression and function of these transporters can contribute to the process of age-associated brain impairment and pathophysiology of neurodegenerative diseases.

Three cases of non-carryover fingolimod-PML: Is the risk in Japan increased?

Objective: To report the course of 3 recent Japanese and European cases of fingolimod-associated progressive multifocal leukoencephalopathy (PML) and to analyze its risk factors and increased incidence in Japan. Methods: Case series and literature review. Results: Fingolimod-associated PML may cause both supratentorial and infratentorial lesions and a pronounced disability. Diagnosis can be challenging because PML lesions (especially infratentorial) can be initially misdiagnosed as extensive MS lesions. Immune reconstitution inflammatory syndrome (IRIS) develops a few weeks after fingolimod discontinuation and is usually mild. Age factor and therapy duration seem to be relevant because most reported patients were older than 45 years and were treated with fingolimod for more than 3 years. Combined IgG/IgM deficiency has been identified as a possible further predisposing condition in 1 case. Another patient developed an endogenous fungal skin infection, as a sign of generally compromised cellular immune response, shortly before PML. None of the reported patients had lymphocyte counts below 200/µl. Two of the 3 reported and 4 of the 21 (19%) registered fingolimod-PML cases occurred in Japan (estimated risk of 0.652 per 1,000 compared with 0.083 per 1.000 worldwide). Conclusions: The risk of PML under fingolimod is low, but there are no reliable predictors. Despite a mild IRIS phase, it causes profound disability. Patients older than 45 years, especially with known comorbid immunodeficiencies or manifestation of other opportunistic infections, should be monitored more closely. Increased surveillance and identification of further risk factors are urgently needed in Japan.

Disturbance of Intracerebral Fluid Clearance and Blood-Brain Barrier in Vascular Cognitive Impairment.

The entry of blood-borne macromolecular substances into the brain parenchyma from cerebral vessels is blocked by the blood-brain barrier (BBB) function. Accordingly, increased permeability of the vessels induced by insult noted in patients suffering from vascular dementia likely contributes to the cognitive impairment. On the other hand, blood-borne substances can enter extracellular spaces of the brain via endothelial cells at specific sites without the BBB, and can move to brain parenchyma, such as the hippocampus and periventricular areas, adjacent to specific sites, indicating the contribution of increased permeability of vessels in the specific sites to brain function. It is necessary to consider influx and efflux of interstitial fluid (ISF) and cerebrospinal fluid (CSF) in considering effects of brain transfer of intravascular substances on brain function. Two pathways of ISF and CSF are recently being established. One is the intramural peri-arterial drainage (IPAD) pathway of ISF. The other is the glymphatic system of CSF. Dysfunction of the two pathways could also contribute to brain dysfunction. We review the effects of several kinds of insult on vascular permeability and the failure of fluid clearance on the brain function.

Phosphorylated NF-κB subunit p65 aggregates in granulovacuolar degeneration and neurites in neurodegenerative diseases with tauopathy.

Granulovacuolar degeneration (GVD) was originally reported in Alzheimer's disease (AD) and later found in aging brains. Pathologically, GVD is thought to be associated with the development of tauopathy, but the precise mechanism remains unknown. Previous studies have suggested that GVD contains proteins associated with an inflammatory signal. In this study, we examined phosphorylated p65 (pp65), which is the activated form of a subunit of nuclear factor-kappa B (NF-κB), in the hippocampus of 21 autopsied cases, including AD, amyotrophic lateral sclerosis cases with optineurin mutation (ALS-OPTN), and a variety of other neurodegenerative disorder cases and normal controls. In all cases, GVDs were immunopositive for pp65. The density of pp65-positive GVDs statistically correlated with that of casein kinase 1 delta (CK1δ), which is known as GVD marker. pp65 was also detected in neurites in AD and ALS-OPTN. The number of neurons with pp65-immunoreactive GVD was significantly higher in the AD group than in the non-AD group. Double immunostaining showed the colocalization of CK1δ and pp65. pp65-positive GVD was found in a neuron with AT8-positive neurofibrillary tangles. Moreover, pp65 was also found in neurites that were immunostained with phosphorylated tau, phosphorylated α-synuclein, or TDP-43 (transactivation response element DNA-binding protein 43 kDa). Therefore, the activation of the NF-κB pathway may be related to the pathology of GVD formation and dementia with tauopathy, including AD and ALS-OPTN. We propose that pp65 is useful as a GVD marker, and that the NF-κB pathway could be a therapeutic target not only for AD, but for age-related neurodegenerative diseases in general.

CSF cystatin C and diffusion tensor imaging parameters as biomarkers of upper motor neuron degeneration in amyotrophic lateral sclerosis.

OBJECTIVES: The establishment of biomarkers for amyotrophic lateral sclerosis (ALS) will be useful for early diagnosis and may provide evidence about pathogenesis. To elucidate whether high-field magnetic resonance (MR) findings and multimodal analysis of cerebrospinal fluid (CSF) levels of cystatin C could be indicators of upper motor neuron (UMN) involvement in ALS. PATIENTS AND METHODS: Patients with ALS (n = 20), multiple sclerosis (n = 15), immune mediated chronic polyneuropathy (n = 17), and acute polyneuropathy (n = 12) were included in this retrospective study. Clinical indices including UMN signs were assessed, and 3.0-Tesla diffusion tensor imaging and MR spectroscopy were performed in patients with ALS. CSF levels of cystatin C were measured using enzyme-linked immunosorbent assay. RESULTS: MR findings indicated that decreased anisotropy, increased diffusion, and increased myo-inositol/creatine ratio were also significantly correlated with UMN involvement in patients with ALS. The CSF cystatin C levels were significantly lower in patients with ALS than in the other three groups. The reduction of CSF cystatin C levels was significantly correlated with clinical UMN involvement (r = -0.505, p =  0.023). CONCLUSIONS: Reduced cystatin C in CSF can reflect UMN involvement as shown in high-field MR of ALS, potentially providing a new biomarker for UMN degeneration in ALS.

Multiple Proteinopathies in Familial ALS Cases With Optineurin Mutations.

Optineurin (OPTN) is a causative gene in familial amyotrophic lateral sclerosis (ALS) with transactivation response element DNA-binding protein of 43 kDa (TDP-43) protein pathology. Here, we report multiple proteinopathies in familial ALS cases with OPTN mutations. We examined the TDP-43, tau, and α-synuclein pathology of ALS cases with OPTN mutations including 2 previously reported cases (Cases 1 and 2) and 1 newly autopsied case (Case 3) that was clinically diagnosed as ALS and Parkinson disease with a heterozygous E478G OPTN mutation. Pathologic examination of Case 3 showed motor neuron degeneration and depigmentation of the substantia nigra. Neurofibrillary tangles (NFTs) were seen in the hippocampus, pontine tegmentum, and spinal cord. Accumulation of multiple proteins including phosphorylated TDP-43-positive neuronal cytoplasmic inclusions, phosphorylated tau (AT8)-positive NFTs, and α-synuclein-positive Lewy bodies were observed in the substantia nigra. The other 2 cases had a similar distribution of tau pathology, but lacked synuclein pathology. Consecutive sections of Case 3 revealed pTDP-43, AT8, and α-synuclein-positive inclusions in the same neuron and double immunofluorescence staining showed aggregation of different proteins (tau and α-synuclein, or tau and TDP-43) in the same neuron. Our results support the notion that OPTN mutations may lead to multiple proteins aggregation and neuronal degeneration.

Spastic paraplegia type 31: A novel REEP1 splice site donor variant and expansion of the phenotype variability.

Mutations in REEP1 have been identified in three types of neurological disorders, autosomal dominant form of Hereditary Spastic Paraplegia type 31 (SPG31), autosomal dominant distal hereditary motor neuronopathy type VB (HMN5B), and autosomal recessive form of congenital axonal neuropathy and diaphragmatic palsy. Previous studies demonstrated different molecular pathogenesis in SPG31, including loss-of-function, gain-of-function and haploinsufficiency. A four-generation family from Japan, including 12 members, was investigated clinically and genetically. Seven affected members displayed pure spastic paraplegia. Impression of genetic anticipation was observed in the family, including tendency of earlier age-at-onset and increasing severity in subsequent generations. Genetic analysis revealed a heterozygous intronic variant, c.303+2T > A, in REEP1, which segregated with disease, and was also identified in one unaffected member. The variant causes exon 4 skipping leading to frame shift and a truncated transcript identified by complementary DNA sequencing of reverse transcription polymerase chain reaction products. Measurement of REEP1 transcripts in lymphocytes demonstrated a reduction through nonsense mediated mRNA decay (NMD). Our study demonstrated further evidence of allelic heterogeneity in SPG31, mutant REEP1 mRNA dosage effects through NMD and intra-familial phenotype variability.

Serum microRNA expression profiling in patients with multiple system atrophy.

Multiple system atrophy (MSA) is a sporadic neurodegenerative disease that is pathologically characterized by α­synuclein positive glial cytoplasmic inclusions in oligodendrocytes. The clinical diagnosis of MSA is often challenging as there are no established biomarkers and diagnoses are now based on clinical findings alone. At present, the etiology and pathogenesis of MSA are unclear. It has been reported that dysregulation of microRNA (miRNA/miR) serves an important role in neurodegenerative disorders including Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis. The miRNA profile of patients with MSA remains to be established. The present study investigated the serum miRNA expression level of 10 patients with MSA, using microarray chips including 668 miRNAs. It was identified that 50 miRNAs were significantly upregulated and 17 miRNAs were significantly downregulated in the serum of the patients with MSA. The most upregulated miRNA was miR­16, which may induce the accumulation of α­synuclein. The target genes of some miRNAs upregulated in MSA (including miR­17, 20a, 24, 25, 30d and 451) were associated with autophagy­associated molecules. The present study concluded that the expression pattern of miRNAs may be a clinical biomarker for MSA and targeting these miRNAs may provide a novel treatment for MSA.

First report of a Japanese family with spinocerebellar ataxia type 10: The second report from Asia after a report from China.

Spinocerebellar ataxia type 10 (SCA10) is an autosomal-dominant cerebellar ataxia that is variably accompanied by epilepsy and other neurological disorders. It is caused by an expansion of the ATTCT pentanucleotide repeat in intron 9 of the ATXN10 gene. Until now, SCA10 was almost exclusively found in the American continents, while no cases had been identified in Japan. Here, we report the first case of an SCA10 family from Japan. The clinical manifestations in our cases were cerebellar ataxia accompanied by epilepsy, hyperreflexia and cognitive impairment. Although the primary pathology in SCA10 in humans is reportedly the loss of Purkinje cells, brain MRI revealed frontal lobe atrophy with white matter lesions. This pathology might be associated with cognitive dysfunction, indicating that the pathological process is not limited to the cerebellum. Examination of the SNPs surrounding the SCA10 locus in the proband showed the "C-expansion-G-G-C" haplotype, which is consistent with previously reported SCA10-positive individuals. This result was consistent with the findings that the SCA10 mutation may have occurred before the migration of Amerindians from East Asia to North America and the subsequent spread of their descendants throughout North and South America.

Acute Intermittent Porphyria Presenting with Posterior Reversible Encephalopathy Syndrome, Accompanied by Prolonged Vasoconstriction.

A 20-year-old Japanese woman had an attack of acute intermittent porphyria (AIP). Magnetic resonance imaging (MRI) revealed symmetrical lesions in the cerebrum and cerebellar hemisphere, corresponding to posterior reversible encephalopathy syndrome (PRES). Our administration of heme arginate gradually improved the clinical condition associated with AIP and the level of metabolite of nitric oxide (NO), which is a vascular dilator. Repeated MRI and magnetic resonance angiography revealed exacerbated PRES, part of which showed a small infarction, accompanied by progressive vasoconstriction. These findings suggest that the recovery of NO by heme replacement alone is insufficient for preventing brain damage during an AIP attack.

Dialysis-induced Subdural Hematoma in an Arachnoid Cyst Associated with Autosomal Dominant Polycystic Kidney Disease.

Arachnoid cyst (AC) is a neurological complication of autosomal dominant polycystic kidney disease (ADPKD). Although an AC can increase the risk of a subdural hematoma, the clinical presentation of bleeding into an AC associated with ADPKD is not well known. We herein report the case of a 59-year-old woman in whom the initiation of hemodialysis for renal failure led to AC bleeding. A change of anticoagulant from heparin to nafamostat mesilate allowed dialysis to continue without rebleeding. These findings suggest that hemodialysis in patients with an AC associated with ADPKD may increase the risk of bleeding. Nafamostat mesilate may be useful in such cases.