Nusinersen for adults with spinal muscular atrophy.

INTRODUCTION: Nusinersen was effective in improving motor function and survival in infantile and childhood-onset spinal muscular atrophy (SMA), and the value of real-world experiences in adult SMA patients increase gradually. Here, we present our clinical experience in adult SMA patients treated with nusinersen according to CHERISH study. MATERIAL AND METHODS: Thirty-two SMA patients treated with nusinersen were included in the study. RESULTS: Median age at nusinersen initiation was 33.5 (20.0-60.0) years and 23 of SMA patients were male. Six (18.8%) patients had SMA type 2, and 26 (81.2%) had SMA type 3. Median follow-up period of patients under nusinersen treatment was 17 months (9-21). Twenty-three patients improved by at least 3 Hammersmith Functional Motor Scale Expanded (HFMSE) points after loading doses. There was significant HFMSE score increase in type 3 patients at each time point, whereas type 2 patients seem to benefit from nusinersen loading doses, subsequently stayed stable. Motor improvement was positively correlated with baseline HFMSE scores in patients whose baseline HFMSE scores were ≤47. There was a correlation between the changes in Amyotrophic Lateral Sclerosis Functional Rating Scale Revised (ALSFRS-R) score and HFMSE scores. Ambulatory patients who could not show clinically meaningful increase in HFMSE scores improved at least 30 m by 6-min walk test (6MWT). CONCLUSION: Overall, 78% of patients have responded to treatment according to HFMSE or 6MWT. ALSFRS-R and 6MWT may be alternative tools to monitor nusinersen effect.

One Disease with two Faces: Semidominant Inheritance of a Novel HTRA1 Mutation in a Consanguineous Family.

OBJECTIVES: To identify the underlying genetic defect for a consanguineous family with an unusually high number of members affected by cerebral small vessel disease. MATERIALS AND METHODS: A total of 6 individuals, of whom 3 are severely affected, from the family were clinically and radiologically evaluated. SNP genotyping was performed in multiple members to demonstrate genome-wide runs-of-homozygosity. Coding variants in the most likely candidate gene, HTRA1 were explored by Sanger sequencing. Published HTRA1-related phenotypes were extensively reviewed to explore the effect of number of affected alleles on phenotypic expression. RESULTS: Genome-wide homozygosity mapping identified a 3.2 Mbp stretch on chromosome 10q26.3 where HTRA1 gene is located. HTRA1 sequencing revealed an evolutionarily conserved novel homozygous c.824C>T (p.Pro275Leu) mutation, affecting the serine protease domain of HtrA1. Early-onset of cognitive and motor deterioration in homozygotes are in consensus with CARASIL. However, there was a clear phenotypic variability between homozygotes which includes alopecia, a suggested hallmark of CARASIL. All heterozygotes, presenting as CADASIL type 2, had spinal disk degeneration and several neuroimaging findings, including leukoencephalopathy and microhemorrhage despite a lack of severe clinical presentation. CONCLUSION: Here, we clearly demonstrate that CARASIL and CADASIL type 2 are two clinical consequences of the same disorder with different severities thorough the evaluation of the largest collection of homozygotes and heterozygotes segregating in a family. Considering the semi-dominant inheritance of HTRA1-related phenotypes, genetic testing and clinical follow-up must be offered for all members of a family with HTRA1 mutations regardless of symptoms.

Functional exercise capacity evaluated by timed walk tests in myasthenia gravis.

INTRODUCTION: We sought to evaluate the test-retest reliability and construct validity of the 6- and 2-minute walk tests (6mWT and 2mWT, respectively) in patients with myasthenia gravis (MG). METHODS: Thirty-one patients with generalized MG were enrolled in this study. The 6mWT, 2mWT, MG-specific quality of life questionnaire Turkish version (MG-QoL15T), quantitative myasthenia gravis test (QMG), and pulmonary function tests were administered. RESULTS: The intraclass correlation coefficients of 2mWT and 6mWT were 0.894 and 0.932, respectively. The 6mWT and 2mWT had moderate correlations with forced vital capacity, maximal inspiratory pressure, QMG score, and MG-QoL15T score (ρ for 6mWT: 0.579, 0.539, -0.572, and -0.474; ρ for 2mWT: 0.460, 0.446, -0.532, -0.457). Both tests had similar performances for predicting disease severity (area under the curve = 0.761 for 6mWT and 0.759 for 2mWT). DISCUSSION: The 6mWT and 2mWT have excellent test-retest reliability as well as moderate construct validity for the evaluation of functional exercise capacity patients with MG. Muscle Nerve 59:208-212, 2019.

Expiratory muscle strength as a predictor of functional exercise capacity in generalized myasthenia gravis.

OBJECTIVE: To investigate the correlations between the 6-minute walk test and disease severity, pulmonary functions, and respiratory muscle performance in patients with generalized myasthenia gravis (MG) and to determine whether MG disease severity, pulmonary functions, and respiratory muscle performance contribute to 6-minute walk test distance in generalized MG. METHODS: This cross-sectional trial was conducted at Hacettepe University in Ankara, Turkey. The study was carried out from February to August 2017. Twenty-eight class II-III MG patients participated in the study. Patients` disease severity was determined with the Myasthenia gravis composite scale. All participants underwent the 6-minute walk test, pulmonary function tests, and respiratory muscle strength and endurance assessment. RESULTS: Approximately 40% of patients` expiratory muscle strength were under the lower limit of normal. Multiple linear regression analysis revealed that the percentage of predicted expiratory muscle strength that patients reached were significant and independent predictor of percentage of 6-minute walk test distance that patients reached according to reference values (R2=0.493, F [1-27]=25.275, p less than 0.001). CONCLUSION: Expiratory muscle strength is a significant determinant of functional exercise performance in generalized MG with mild or moderate weakness affecting muscles other than the ocular muscles.

Cellular infiltrates in skin and sural nerve of patients with polyneuropathies.

INTRODUCTION: The aim of this study was to determine the diagnostic usefulness of skin punch biopsies with emphasis on visualization and quantification of T-cells and macrophages in patients with polyneuropathies. METHODS: We quantified inflammatory cells in skin samples (lower leg, upper thigh) in 187 patients and compared data with counts in their sural nerve biopsies and with skin biopsies from 32 healthy volunteers. RESULTS: Vessel-bound T-cells and macrophages were increased in proximal and distal skin samples of neuropathy patients compared with controls (P < 0.001 in both). Patients with vasculitic neuropathy had increased T-cell and macrophage counts in distal skin compared with controls (P < 0.01; for scattered macrophages/mm2 diagnostic sensitivity 71% and specificity 79%). In patients with vasculitic neuropathy, distal skin perivascular inflammatory cell counts also correlated with those in sural nerve biopsies (P < 0.001). CONCLUSION: Neuropathy per se may lead to skin inflammation. In cases of possible vasculitic neuropathy, skin biopsy may be an additional tool to support the diagnosis. Muscle Nerve 55: 884-893, 2017.

Cutaneous activation of rage in nonsystemic vasculitic and diabetic neuropathy.

INTRODUCTION: We asked whether the receptor of advanced glycation end products (RAGE) is related to dermal inflammation in nonsystemic vasculitic neuropathy (NSVN) and diabetic neuropathy (DN) and whether its presence in skin is comparable to that in sural nerve biopsies. METHODS: We immunoreacted skin biopsy samples from 17 NSVN and 7 DN patients who had also undergone sural nerve biopsy, and 14 healthy controls with antibodies to advanced glycation end products (AGE), RAGE, T-cells, and macrophages. RESULTS: AGE and RAGE immunoreactivity were present in vessels of nerve biopsies from NSVN and DN. AGE and RAGE were increased in dermal endothelial cells and T-cells of NSVN and DN patients compared with controls. CONCLUSIONS: Dermal RAGE is increased in NSVN and DN, supporting the concept of a role of the RAGE pathway in the pathophysiology of dermal inflammation and skin denervation in NSVN and DN.

The course of myasthenia gravis with systemic lupus erythematosus.

BACKGROUND: Systemic lupus erythematosus (SLE) is one of the autoimmune diseases, which is rarely reported with Myasthenia Gravis (MG). In the literature, the clinical features of MG in these patients were not mentioned in detail. Here, we want to present our five patients with MG and SLE. METHODS: Between 2000 and 2010, 132 MG patients were evaluated and have been followed up in our institution. Five patients had MG with SLE and eleven patients had antinuclear antibody (ANA) positivity without SLE symptoms. The clinical, laboratory findings and treatment responses were reviewed. RESULTS: All patients had generalized MG and four of five patients experienced at least one myasthenic crisis. The response to corticosteroid was poor; consequently, they needed immunosuppressive treatments, IVIg or plasmapheresis. Although in the literature thymectomy was accused of the precipitation of SLE, in our series SLE symptoms preceded thymectomy. CONCLUSION: We would like to point out that MG and SLE being two autoimmune diseases may coexist. This coexistence might cause a more severe myasthenic course compared to MG alone; therefore, these patients need a close and frequent follow-up.

Differentiating recurrent Guillain-Barre syndrome and acute-onset chronic inflammatory polyneuropathy: literature review.

Guillain-Barre syndrome (GBS) is an acute-onset immune-mediated polyneuropathy characterized by ascending symmetrical muscle weakness, diminished reflexes, and sensory symptoms. While GBS typically follows a monophasic course, some patients experience treatment-related fluctuations or recurrences, posing diagnostic challenges in distinguishing GBS from acute-onset chronic inflammatory polyneuropathy (A-CIDP). A-CIDP, may present acutely, simulating GBS, with a nadir in less than 8 weeks, subsequently evolving into a chronic or relapsing course. The distinction between recurrent GBS and A-CIDP is crucial, as A-CIDP necessitates long-term immunosuppression. A PubMed search was conducted using the search terms 'recurrent Guillain Barre syndrome' and 'acute onset CIDP' focusing on studies in the English language, published between January 1, 2004 and April 30, 2023. Overlapping clinical features, particularly in the early stages, complicate differentiation between recurrent GBS and CIDP. Electrophysiological studies, ultrasonography, and immunological markers have been explored for discrimination; however, definitive criteria for differentiation remain elusive. Recent follow-up studies have further blurred the boundaries between recurrent GBS and A-CIDP, suggesting the persistence of underlying immune processes even in GBS patients without clinical deterioration. This emphasizes the necessity of reevaluating diagnostic criteria and treatment strategies. In conclusion, distinguishing recurrent GBS from A-CIDP remains an ongoing challenge. Existing evidence questions the categorization of recurrent GBS as a distinct entity, challenging its very existence. Continued research is necessary to refine diagnostic criteria and deepen our understanding of these conditions, ultimately advancing patient care. This review delves into the intricacies of recurrent GBS and A-CIDP differentiation and highlights the need for a reevaluation of the recurrent GBS concept.

The evaluation of small fibers in multiple sclerosis.

BACKGROUND: Dysesthetic or ongoing extremity pain is a common symptom in all multiple sclerosis (MS) types. Although the pathology of the disease is the demyelination of central neurons, the patients may also complain of neuropathic pain in distal extremities that is generally related to A-delta and C fiber dysfunction. It is not known whether thinly myelinated and unmyelinated fibers are affected in MS patients. We aim to investigate the small fiber loss and its length dependency. METHODS: We evaluated the skin biopsy taken from proximal and distal leg of MS patients with neuropathic pain. Six patients with primary progressive MS (PPMS), seven with relapsing-remitting MS (RRMS), seven with secondary progressive MS (SPMS) and as a control group ten age and sex-matched healthy controls were included. Neurological examination, electrophysiological evaluation and DN4 questionnaire were performed. Subsequently, skin punch biopsy from 10 cm above the lateral malleolus and proximal thigh were done. The biopsy samples were stained with PGP9.5 antibody and intraepidermal nerve fiber density (IENFD) was determined. RESULTS: The mean proximal IENFD was 8.58±3.58 fibers/mm among MS patients and 14.72±2.89 fiber/mm among healthy controls (p=0.001). However, the mean distal IENFD did not differ between MS patients and healthy controls (9.26±3.24 and 9.75±1.6 fiber/mm respectively. Although proximal and distal IENFD tends to be lower in MS patients with neuropathic pain, there was no statistically significant difference between MS patients with and without neuropathic pain CONCLUSION: Although MS is a demyelinating disease, unmyelinated fibers can also be affected. Our findings suggest non-length dependent small fiber neuropathy in MS patients.

Two distinct skeletal muscle microRNA signatures revealing the complex mechanism of sporadic ALS.

Skeletal muscle pathology is thought to have an important role in the onset and/or progression of amyotrophic lateral sclerosis (ALS), which is a neurodegenerative disorder characterized by progressive muscle weakness. Since miRNAs are recognized as important regulatory factors of essential biological processes, we aimed to identify differentially expressed miRNAs in the skeletal muscle of sporadic ALS patients through the combination of molecular-omic technologies and bioinformatic tools. We analyzed the miRnome profiles of skeletal muscle biopsies acquired from ten sALS patients and five controls with Affymetrix GeneChip miRNA 4.0 Array. To find out differentially expressed miRNAs in patients, data were analyzed by The Institute for Genomic Research-Multi Experiment Viewer (MeV) and miRNAs whose expression difference were statistically significant were identified as candidates. The potential target genes of these miRNAs were predicted by miRWalk 2.0 and were functionally enriched by gene ontology (GO) analysis. The expression level of priority candidates was validated by quantitative real-time PCR (qRT-PCR) analysis. We identified ten differentially expressed miRNAs in patients with a fold change threshold ≥ 2.0, FDR = 0. We identified ten differentially expressed miRNAs in patients with a fold change threshold ≥ 2.0, FDR = 0. Nine out of the ten miRNAs were found to be related to top three enriched ALS-related terms. Based on the qRT-PCR validation of candidate miRNAs, patients were separated into two groups: those with upregulated miR-4429 and miR-1825 expression and those with downregulated miR-638 expression. The different muscle-specific miRNA profiles in sALS patients may indicate the involvement of etiologic heterogeneity, which may allow the development of novel therapeutic strategies.

Comprehensive evaluation of velopharyngeal function in myasthenia gravis patients.

PURPOSE: Hypernasality, which is a symptom of dysarthria, may be seen in patients with Myasthenia Gravis with bulbar symptoms. However, there is not enough evidence to show that these patients may have velopharyngeal dysfunction. This study investigates the features of velopharyngeal function in myasthenia gravis patients using objective and subjective measurement tools. METHODS: Ten adult myasthenia gravis patients with bulbar symptoms and ten adult myasthenia gravis patients without bulbar symptoms were recruited for this study. Ten healthy subjects were also included as the control group. The nasalance scores of the participants were determined using a nasometer. The degree and pattern of velopharyngeal closure were scored using flexible nasoendoscopy during speech, blowing, dry swallowing, and food swallowing. Perceptual hypernasality was assessed. RESULTS: Velopharyngeal dysfunction was detected in 50% of the myasthenia gravis patients with bulbar symptoms. Velopharyngeal dysfunction was not seen in myasthenia gravis patients without bulbar symptoms. The degree of velopharyngeal closure in patients with bulbar symptoms differed depending on the tasks being performed. No significant difference in velopharyngeal closure patterns was observed between the groups (p < 0.05). CONCLUSION: Myasthenia gravis patients with bulbar involvement may have velopharyngeal dysfunction. It is important to conduct a comprehensive evaluation to assess all aspects of the velopharyngeal function.

Multimodal assessment of intensive care unit-acquired weakness in severe stroke patients.

BACKGROUND: Intensive care unit-acquired weakness (ICUAW) defines generalized muscle weakness seen in critically ill patients in the absence of other causative factors. Herein, we aimed to evaluate ICUAW in stroke patients by electrodiagnostic testing, histopathology, and assessment of respiratory complex activities (RCA), to define the frequency of ICUAW in this patient group, and to reach new parameters for early prediction and diagnosis. METHODS: We prospectively recruited twenty-four severe acute stroke patients during a sixteen-month period. In addition to serial nerve conduction studies (NCS), we performed muscle biopsy and RCA analysis on the non-paretic side when ICUAW developed. Patients undergoing orthopedic surgery without metabolic and neuromuscular diseases constituted the control group for RCA. Survival and longitudinal data were analyzed by joint modeling to determine the relationship between electrophysiological parameters and ICUAW diagnosis. RESULTS: Eight patients (33%) developed ICUAW, and six of them within the first two weeks. Extensor digitorum brevis, abductor digiti minimi (ADM), rectus femoris and vastus medialis (VM) compound muscle action potential (CMAP) amplitudes showed a significant decrease in the ICUAW group. VM CMAP amplitude (BIC = 358.1574) and ADM CMAP duration (BIC = 361.1028) were the best-correlated parameters with ICUAW diagnosis. The most informative electrophysiological findings during the entire study were obtained within the first 11 days. Muscle biopsies revealed varying degrees of type 2 fiber atrophy. Complex I (p = 0.003) and IV (p = 0.018) activities decreased in patients with ICUAW compared to controls. CONCLUSION: VM CMAP amplitude and ADM CMAP duration correlate well with ICUAW diagnosis, and may aid in the early diagnosis.

The functional and structural evaluation of small fibers in asymptomatic carriers of TTR p.Val50Met (Val30Met) mutation.

Therapeutic advances in hereditary amyloid transthyretin (ATTRv) amyloidosis with polyneuropathy extended life expectancy and delayed symptom progression especially in patients with early disease. Thus, detection and monitoring of asymptomatic carriers gained importance. However, there is still limited consensus on genetic screening of ATTRv-polyneuropathy patients' family members and diagnostic tests that must be done in the follow-up. In this study, we followed prospectively five asymptomatic carriers of a family with ATTRV30M (p.Val50Met) mutation by different diagnostic tests for three years. The carriers were followed by neurological examination, nerve conduction studies, sympathetic skin response test, heart rate variability, SFN-SIQ and DN4 questionnaires, quantitative sensory testing (QST), skin biopsy and in vivo corneal confocal microscopy. Nerve conduction studies, sympathetic skin response test and heart rate variability were normal in all for three years. Baseline QST and SFN-SIQ were normal but became abnormal during follow-up of two individuals who developed small fiber neuropathy symptoms. Baseline intraepidermal nerve fiber density was low in three carriers and decreased to below normative values in all during follow-up, while corneal sub-basal nerve density was low in all carriers compared to controls during the entire follow-up. Thus, our study showed that SFN-SIQ and QST are useful diagnostic tools to detect the transition to symptomatic ATTRv-polyneuropathy.

Biologia Futura: the importance of 3D organoids-a new approach for research on neurological and rare diseases.

3D cell cultures and organoid approach are increasingly being used for basic research and drug discovery of several diseases. Recent advances in these technologies, enabling research on tissue-like structures created in vitro is very important for the value of the data produced. Application of 3D cultures will not only contribute to advancing basic research, but also help to reduce animal usage in biomedical science. The 3D organoid approach is important for research on diseases where patient tissue is difficult to obtain. Therefore, this review aims to show recent advances in the 3D organoid technology in disease modeling and potential usage in translational and personalized medicine of diseases with limited patient material such as neurological diseases and rare diseases.

Toscana virus associated with Guillain-Barré syndrome: a case-control study.

Guillain-Barré syndrome (GBS) is an acute-onset, immune-mediated polyradiculoneuropathy, often precipitated by an antecedent infection. An association of GBS with vector-borne viral infections has been suggested, with evidence for the involvement of Zika, Dengue, Chikungunya and West Nile virus (WNV). This prospective case-control study was conducted to identify vector-borne viral infections in GBS. Thirteen individuals newly diagnosed as GBS were enrolled. Disease severity, prognostic factors and nerve conduction patterns were assessed. Eleven individuals with non-infectious conditions requiring cerebrospinal fluid (CSF) analysis were included as controls. Plasma, CSF and urine specimens were evaluated via nucleic acid amplification assays aimed to detect a broad spectrum of viruses. WNV and Toscana virus (TOSV) IgM/IgG antibodies were screened using commercial immunofluorescence assays and confirmed via virus neutralization tests (VNT). Partial TOSV nucleocapsid and genotype 1 polymerase sequences were detected in CSF of a patient with normal pressure hydrocephalus. Two control subjects had VNT-confirmed TOSV IgM in plasma. VNT-confirmed WNV and TOSV IgG were detected in 15.4% and 61.5% of GBS patients, respectively. Variations in WNV IgG and TOSV IgM detection rates were not statistically significant among study cohorts. However, TOSV IgG was significantly more frequent in GBS patients. No difference was observed for disease form or prognostic scores for virus markers. Follow-up serological profiles were identical to the initial findings. We have identified TOSV as a potential precipitating agent in GBS, with some rare clinical presentations of symptomatic TOSV infections.

Reliability and Validity of Turkish Myasthenia Gravis-Activities of Daily Living Scale.

Linguistic, reliable, and valid secondary efficacy measures are important in clinical settings and studies. The aim of the study is to report test-retest reliability and construct validity of Turkish version of Myasthenia Gravis-Activities of Daily Living Scale (MG-ADL-T) in Myasthenia Gravis (MG) patients. Fifty-two ocular and generalized individuals with MG, applying to rehabilitation center, were included in the study. MG-ADL-T, MG quality-of-life questionnaire (MG-QoL), MG composite (MGC), quantitative MG score (QMGS), and pulmonary function test were administered. Reliability was assessed with intraclass correlation coefficient (ICC) and Cronbach's alpha. Spearman correlation test and receiver operating characteristic (ROC) analysis were performed for construct validity. MG-ADL-T had fair internal consistency (Cronbach's α = .67), excellent test-retest reliability (ICC = 0.96) and moderate construct validity (MG-QoL, r = 0.59; QMGS, r = .58; MGC, r = .68). MG-ADL, a unique scale that evaluates activities of daily living (ADL), has good test-retest reliability and construct validity in Turkish MG patients.

Neuropathic Pain Frequency in Neurology Outpatients: A Multicenter Study.

INTRODUCTION: Neuropathic pain is common, but the frequency of misdiagnosis and irrational treatment is high. The aim of this study is to evaluate the rate of neuropathic pain in neurology outpatient clinics by using valid and reliable scales and review the treatments of patients. METHODS: The study was conducted for 3 months in eleven tertiary health care facilities. All outpatients were asked about neuropathic pain symptoms. Patients with previous neuropathic pain diagnosis or who have neuropathic pain symptoms were included and asked to fill painDETECT and douleur neuropathic en 4 questions (DN4) questionnaire. Patients whose DN4 score is higher than 3 and/or painDETECT score higher than 13 and/or who are on drugs for neuropathic pain were considered patients with neuropathic pain. The frequency of neuropathic pain was calculated and the treatments of patients with neuropathic pain were recorded. RESULTS: Neuropathic pain frequency was 2.7% (95% CI: 1.5-4.9). The most common cause was diabetic neuropathy. According to painDETECT, the mean overall pain intensity was 5.7±2.4, being lower among patients receiving treatment. Pharmacological neuropathic pain treatment was used by 72.8% of patients and the most common drug was pregabalin. However, 70% of those receiving gabapentinoids were using ineffective doses. Besides, 4.6% of the patients were on medications which are not listed in neuropathic pain treatment guidelines. CONCLUSION: In our cohort, the neuropathic pain severity was moderate and the frequency was lower than the literature. Although there are many guidelines, high proportion of patients were being treated by ineffective dosages or irrational treatments.

A Novel Amplification-Refractory Mutation System-PCR Strategy to Screen MT-TL1 Pathogenic Variants in Patient Repositories.

Aim: Pathogenic variants within mitochondrial tRNA and rRNA genes negatively affect protein synthesis function and cause oxidative phosphorylation defects. The majority of mitochondrial cytopathies are caused by pathogenic point variants within the mitochondrial tRNA gene for leucine (MT-TL1). This study was designed to evaluate a novel amplification-refractory mutation system (ARMS)-PCR based assay to screen patient samples with a clinical diagnosis of mitochondrial cytopathies. Methods: Tissue DNA samples from 219 affected individuals were screened for the pathogenic variants m.3271T>C, m.3291Ty >C, m.3303C>T, m.3256C>T, and m.3260A>G along with the most frequent m.3243A>G mutation in the MT-TL1 gene. The assay included a "High Resolution Melt curve analysis" to enhance detection limits. The precision of the assay was verified using synthetic controls with variant heteroplasmy ratios. Results: The screening identified the second reported m.3303C>T case as well as two patients with m.3243A>G variants and a rare variant exhibiting m.3290T>C. Conclusion: ARMS-PCR is superior to Sanger sequencing for the detection of variations exhibiting low heteroplasmy. These results provide "proof of concepts" for the implementation of this application for future screening of rare mtDNA variations in sample repositories.

Comprehensive clinical, biochemical, radiological and genetic analysis of 28 Turkish cases with suspected metachromatic leukodystrophy and their relatives.

Metachromatic leukodystrophy (MLD) is a glycosphingolipid storage disease caused by deficiency of the lysosomal enzyme arylsulfatase A (ASA) or its activator protein saposin B. MLD can affect all age groups in severity varying from a severe fatal form to milder adult onset forms. Diagnosis is usually made by measuring leukocyte ASA activity. However, this test can give false negative or false positive laboratory results due to pseudodeficiency of ASA and saposin B deficiency, respectively. Therefore, we aimed to evaluate patients with suspected MLD in a Turkish population by comprehensive clinical, biochemical, radiological, and genetic analyses for molecular and phenotypic characterization. We analyzed 28 suspected MLD patients and 41 relatives from 24 families. ASA activity was found to be decreased in 21 of 28 patients. Sixteen patients were diagnosed as MLD (11 late infantile, 2 juvenile and 3 adult types), 2 MSD, 2 pseudodeficiency (PD) and the remaining 8 patients were diagnosed as having other leukodystrophies. Enzyme analysis showed that the age of onset of MLD did not correlate with residual ASA activity. Sequence analysis showed 11 mutations in ARSA, of which 4 were novel (p.Trp195GlyfsTer5, p.Gly298Asp, p.Arg301Leu, and p.Gly311Asp), and 2 mutations in SUMF1 causing multiple sulfatase deficiency, and confirmed the diagnosis of MLD in 2 presymptomatic relatives. All individuals with confirmed mutations had low ASA activity and urinary sulfatide excretion. Intra- and inter-familial variability was high for the same ARSA missense genotypes, indicating the contribution of other factors to disease expression. Imaging findings were evaluated through a modified brain MRI scoring system which indicated patients with protein-truncating mutations had more severe MRI findings and late-infantile disease onset. MRI findings were not specific for the diagnosis. Anti-sulfatide IgM was similar to control subjects, and IgG, elevated in multiple sulfatase deficiency. In conclusion, the knowledge on the biochemical, clinical and genetic basis of MLD was expanded, a modified diagnostic laboratory algorithm for MLD based on integrated evaluation of ASA activity, urinary sulfatide excretion and genetic tests was devised.

The histopathological evaluation of small fiber neuropathy in patients with vitamin B12 deficiency.

Small fiber neuropathy (SFN), due to loss of A-delta and unmyelinated C fibers, is a cause of neuropathic pain. Although the patients with vitamin B12 deficiency are included in SFN studies in the literature, there is no histopathological study investigating the small fiber loss solely in patients with vitamin B12 deficiency. In this pilot study, we aim to demonstrate the intraepidermal nerve fiber density (IENFD) in skin punch biopsy of patients with vitamin B12 deficiency. Ten patients with vitamin B12 deficiency suffering from neuropathic pain and as control group ten patients with vitamin B12 deficiency without neuropathic pain were included. Neurological examination, electrophysiological evaluation, and DN4 questionnaire were performed. Subsequently, skin punch biopsy 10 cm above the lateral malleolus was done. The biopsy samples were stained with PGP9.5 antibody, and IENFD was determined. IENFD was low in two groups compared to their age normative values. The median of IENFD was 3.345 (1.12-5.32) in patients with neuropathic pain and 6. 20 (4.6-9.8) in controls (p < 0.001). Our pilot study showed that vitamin B12 deficiency causes symptomatic as well as asymptomatic small fiber loss like diabetes mellitus.