Nitrous Oxide-induced Myeloneuropathy Due to Recreational Abuse

BACKGROUND

The recreational use of nitrous oxide (N2O) has increased in recent years with a noticeable surge in the incidence of nitrous oxide-related myeloneuropathy.

OBJECTIVES

To raise awareness of increasing myeloneuropathy due to recreational nitrous oxide misuse in Israel.

METHODS

We conducted a case series documenting the clinical and investigative features of eight patients presenting with nitrous oxide-induced myeloneuropathy who were admitted to our departments.

RESULTS

Paresthesia was the chief complaint in all patients, with sensory gait ataxia being a common feature, which was often accompanied by Romberg's sign and mild lower limb weakness. Vitamin B12 levels were below the normal range in seven patients, accompanied by elevated homocysteine and methylmalonic acid levels. Magnetic resonance imaging scans revealed hyperintense signals in the dorsal columns of the cervical spine. All patients improved following vitamin B12 injections.

CONCLUSIONS

Enhancing awareness, prompting the use of appropriate investigations, and advocating for timely treatment are needed to overcome the risks associated with nitrous oxide misuse.

Riboflavin-responsive lipid-storage myopathy in elderly patients

There are scarce reports of riboflavin-responsive lipid storage myopathy in elderly patients with onset in their sixties. We describe three elderly patients with riboflavin-responsive lipid-storage myopathy. All three patients (aged 67-71 years on first examination) had subacute onset of neck extensors and proximal limb weakness progressing to inability to rise from a sitting position or to walk. Muscle biopsies showed vacuoles with lipid content, mainly in type 1 fibers. Genetic analysis failed to identify any pathogenic variant in one patient, identified a heterozygous variant of uncertain significance c.812 A > G; p.Tyr271Cys in the ETFDH gene in the second patient, and revealed a heterozygote likely pathogenic variant c.1286-2 A > C in the ETFDH gene predicted to cause abnormal splicing in the third patient. All patients responded to treatment with riboflavin and carnitine, and regained normal strength. This report emphasizes the importance of muscle biopsy in revealing treatable lipid storage myopathy in elderly patients with progressive myopathy of unidentifiable cause.

Glycogen Debrancher Enzyme Deficiency Myopathy

ABSTRACT

Glycogen storage disease type III is a rare inherited disease caused by decreased activity of glycogen debranching enzyme. It affects primarily the liver, cardiac muscle, and skeletal muscle. Pure involvement of the skeletal muscle with adult onset is extremely rare. We report on a patient with myopathy due to glycogen storage disease III, and describe the clinical features, and pathologic and genetic findings.

Age-Related Clinical Presentation of MOG-IgG Seropositivity in Israel

Introduction: Myelin oligodendrocyte glycoprotein (MOG) antibody associated disorders (MOGAD) have been recognized over the past 10 years as distinct inflammatory, demyelinating diseases of the central nervous system (CNS). Antibodies against MOG are found mostly in patients with optic neuritis (ON), acute disseminated encephalomyelitis (ADEM), and aquaporin-4 antibody (AQP4-abs)-seronegative neuromyelitis optica spectrum disorders (NMOSD). However, data on the disease course and disability outcomes of these patients are scarce. Aim: To describe clinical and paraclinical features associated with MOG antibodies (abs) in a cohort of patients in Israel, and to assess baseline prognostic features of MOG-ab-associated diseases after a first acute demyelinating event. Methods: MOG-abs were identified in serum using a cell-based assay, and clinical data were collected from the patients' medical records. Results: Of 683 patients with demyelinating diseases tested for MOG-abs, 53 were positive (7.7%), with ON the most common presenting phenotype (68%). The age range of MOG-abs seropositive patients was 1-66 years, with increased prevalence in children (19% compared to 6.7% in adults) (p < 0.01). The highest prevalence of seropositivity was observed in children aged younger than 10 years (25.5%), followed by those aged 31-40 years (16.6%). Conclusions: MOGAD are distinct autoimmune diseases that occurs at all stages of life with a significantly higher prevalence in children; the main clinical presenting phenotype in the entire cohort is ON and young children most often presented with ON or ADEM. Our data highlight the need for repeated evaluation of MOG-abs in patients with acquired CNS demyelinating disorders, especially in children under 10 and adults between 31 and 40 years of age.

Electrical stimulation of the posterior tibial nerve reduces neuropathic pain in patients with polyneuropathy

Peripheral neuropathic pain (PNP) is caused by neuronal damage to the peripheral nervous system and usually affects the distal extremities. This open-label study examined the effect of short-term peripheral nerve stimulation (PNS) on individuals with PNP due to polyneuropathy. A total of 12 patients (mean age, 63.0 ± 10.0 years, 41.7% male) with daily bilateral PNP for at least 6 months (mean duration, 7.4 ± 7.8 years) received a total of six direct electrical stimulation therapies to the posterior tibial nerve at 3-4-day intervals. Eight patients completed the study and were included in the efficacy analysis. The average pain at baseline was 36.6 ± 3.80 estimated by the Short-Form McGill Pain Questionnaire. After the last stimulation, pain was significantly reduced by 85.5% to 4.88 ± 3.1 (p = 0.008). Six patients (75%) had over 50% decrease in pain after the first stimulation therapy and 99.2% after the final stimulation therapy. The patients also reported statistically significant decreases in pain level (measured by visual analog scale), ranging from 54.85% to 87.50% after each of the stimulations as compared to the pain experienced prior to the stimulations. The procedure was safe without any serious adverse events. PNS has demonstrated excellent efficacy and improvement of PNP symptoms. Further studies in larger patient populations are warranted.

Two novel MYH7 proline substitutions cause Laing Distal Myopathy-like phenotypes with variable expressivity and neck extensor contracture

Background

Human skeletal muscles express three major myosin heavy chain (MyHC) isoforms: MyHCIIx (MYH1) in fast type 2B muscle fibers, MyHCIIa (MYH2) in fast type 2A fibers and MyHCI/β-cardiac MyHC (MYH7) in slow type I skeletal fibers and cardiac ventricles. In line with its expression pattern, MYH7 mutations have been reported in association with hypertrophic or dilated cardiomyopathy, skeletal myopathies or a combination of both. We analyzed the clinical and molecular phenotype of two unrelated families of Jewish Moroccan ancestry that presented with apparently autosomal dominant inheritance of progressive Laing-like distal myopathy with non-specific myopathic changes, but uncommon marked contractures and wasting of the neck extensors.

Methods

Clinical phenotyping, whole exome sequencing and restriction analysis, generation of mutants followed by cell culture transfection and imaging.

Results

Using whole exome sequencing we identified in both families two novel heterozygous proline substitutions located in exon 31 of MYH7 within its rod domain: c.4309G>C (p.Ala1437Pro) and c.4301G>C (p.Arg1434Pro). Here we show that the phenotype caused by these mutations includes marked cervical muscle contracture, and report that the severity of the phenotype varies significantly, to the extent of non-penetrance in one of the families. Finally, we provide evidence that both proline substitutions impair myosin self-assembly in non-muscle cells transfected with β-myosin constructs carrying the mutations, but do not prevent incorporation of the mutant molecules into the sarcomere.

Conclusions

This study expands our clinical and molecular knowledge of MYH7 rod mutations causing skeletal myopathies, and underscores the importance of discussing disease penetrance during genetic counseling.

Adult onset limb-girdle muscular dystrophy - a recessive titinopathy masquerading as myositis

Rarely, inflammation can be present in genetic myopathies, such as dysferlinopathies, facioscapulohumeral muscular dystrophy and GNE-myopathy (hereditary inclusion body myopathy). This may lead to erroneous initial diagnosis and unnecessary therapy which bear serious side effects. We report on an unusual case of mutations in the TTN gene presenting with inflammatory infiltrates in the muscle biopsy. Only after intensive immune-modulating therapies failed, a genetic myopathy was considered. Exome sequencing and search for mutated muscle protein-encoding genes disclosed compound heterozygous mutations in TTN: K26320T and A6135G. The parents carry one each of the mutations. Titinopathy could be considered also in patients presenting with inflammatory infiltrates resistant to therapy.

Survival-apoptosis associated signaling in GNE myopathy-cultured myoblasts

GNE Myopathy (GNEM) is a neuromuscular disorder caused by mutations in the GNE gene. It is a slowly progressive distal and proximal muscle weakness sparing the quadriceps. In this study, we applied our model of mutated M743T GNE enzyme skeletal muscle-cultured myoblasts and paired healthy controls to depict the pattern of signaling proteins controlling survival and/or apoptosis of the PI3K/AKT, BCL2, ARTS/XIAP pathways, examined the effects of metabolic changes/stimuli on their expression and activation, and their potential role in GNEM. Immunoblot analysis of the GNEM myoblasts indicated a notable increased level of activated PTEN and PDK1 and a trend of relative differences in the expression and activation of the examined signaling molecules with variability among the cultures. ANOVA analysis showed a highly significant interaction between the level of PTEN and the patients groups. In parallel, the interaction between the level of BCL2, BAX and PTEN with the specific PI3K/AKT inhibitor-LY294002 was highly significant for BCL2 and nearly significant for PTEN and BAX. The pattern of the ARTS/XIAP signaling proteins of GNEM and the paired controls was variable, with no significant differences between the two cell types. The response of the GNEM cells to the metabolic changes/stimuli: serum depletion and insulin challenge, as indicated by expression of selected signaling proteins, was variable and similar to the control cells. Taken together, our observations provide a clearer insight into specific signaling molecules influencing growth and survival of GNEM muscle cells.

Myotonia in DNM2-related centronuclear myopathy

Centronuclear myopathy (CNM) is a rare hereditary myopathy characterized by centrally located muscle fiber nuclei. Mutations in the dynamin 2 (DNM2) gene are estimated to account for about 50 % of CNM cases. Electromyographic recordings in CNM may show myopathic motor unit potentials without spontaneous activity at rest. Myotonic discharges, a distinctive electrical activity caused by membrane hyperexcitability, are characteristic of certain neuromuscular disorders. Such activity has been reported in only one CNM case without a known genetic cause. We sequenced the DNM2 gene and the genes associated with myotonia (CLCN1, SCN4A, DMPK and ZNF9) in a sporadic adult patient with CNM and myotonic discharges. Sequencing the entire coding region and exon-intron boundaries revealed a heterozygous c.1106g-a substitution in exon 8, resulting in a R369Q change in the DNM2. Sequencing the CLCN1, SCN4A, DMPK and ZNF9 genes ruled out mutations in these genes. This is the first report of DNM2-related CNM presenting with myotonia. The diagnosis of CNM should be considered in patients with myotonic discharges of an unknown cause.

Oculopharyngeal muscular dystrophy among Bulgarian Jews: a new cluster?

BACKGROUND

Oculopharyngeal muscular dystrophy (OPMD) produced by the (GCG)13 expansion mutation in the PABPN1 gene is frequent among Uzbek Jews in Israel.

OBJECTIVES

To describe the phenotypic and genotypic features in five Bulgarian Jewish patients, from different families, with autosomal dominant OPMD.

METHODS

We performed clinical follow-up, electrodiagnostic tests and mutation detection. Blood samples were obtained after informed consent and DNA was extracted; measurement of GCG repeats in both PABPN1 alleles and sequencing of OPMD mutations were performed according to standard techniques.

RESULTS

We identified five patients (four females), aged 58 to 71 years, with bilateral ptosis, dysphagia, dysphonia (n = 3) and myopathic motor units by electromyography. In all patients we noticed proximal weakness of the upper limbs with winging scapulae in three of them. All cases shared the (GCG)13-(GCG)10 PABPN1 genotype.

CONCLUSIONS

OPMD among Bulgarian Jews is produced by a (GCG)13 expansion, identical to the mutation in Uzbek Jews and French Canadians. In addition to the classical neurological and neuro-ophthalmological features, early shoulder girdle weakness is common in Bulgarian Jewish patients; this is an unusual feature during the early stages of OPMD produced by the same mutation in other populations. We suggest that besides the disease-producing GCG expansion, additional ethnicity-related genetic factors may influence the OPMD phenotype. OPMD is a rare disease, and the identification of five affected families in the rather small Bulgarian Jewish community in Israel probably represents a new cluster; future haplotype studies may elucidate whether a founder effect occurred.

Association of the M3151 variant in the transient receptor potential vanilloid receptor-1 (TRPV1) gene with type 1 diabetes in an Ashkenazi Jewish population

BACKGROUND

Type 1 diabetes in humans is an autoimmune disease in which Tcells target pancreatic islets of Langerhans, leading to the progressive destruction of the insulin-producing beta cells. Both genetic and environmental factors contribute to the development of autoimmune diabetes. The non-obese diabetic (NOD) mouse model of human type 1 diabetes demonstrates two missense mutations in the transient receptor potentialvanilloid receptor-1 (TRPVi) gene.

OBJECTIVES

To investigate whether polymorphism in the TRPV1 gene may play a role in the predisposition to human type 1 diabetes.

METHODS

We genotyped 146 Ashkenazi Jewish type 1 diabetic patients and 205 Ashkenazi Jewish healthy controls for the rs222747 (M3151), rs224534 (T4691) and rs8065080 (1585V) variants of the TRPV1 gene.

RESULTS

There was a significant increase in the rs222747 (M3151) variant of the TRPV1 gene in the type 1 diabetes cohort compared to the control: rs222747 (M3151) homozygous: (61% vs. 48.3%, P = 0.02). Logistic regression analysis revealed that type 1 diabetes was significantly associated with rs222747 (M3151), such that having diabetes increased the odds of rs222747 homozygosity (M3151) by 67.2%, odds ratio 1.6, 95% confidence interval 1.08-2.57, P < 0.02. No difference was found in the rs224534 (T4691) and rs8065080 (1585V) allelic variants. There was no difference in any of the TRPV1 variants by gender, age when type 1 diabetes was diagnosed, body mass index, glycemic control, blood pressure, positive autoantibodies (ICA, GAD, IAA), and other autoimmune diseases.

CONCLUSIONS

Our study demonstrates that TRPV1 may be a susceptible gene for type 1 diabetes in an Ashkenazi Jewish population. These results should be replicated in the same ethnic group and in other ethnic groups.

Neonatal vocal cord paralysis-an early presentation of hereditary neuralgic amyotrophy due to a mutation in the SEPT9 gene

Hereditary neuralgic amyotrophy is a rare autosomal dominant disorder involving recurrent episodes of painful brachial plexus neuropathies. Involvement of other nerves has been described in some families. The age of onset is from infancy to adulthood. Mutations in the SEPT9 gene were identified in approximately half of the hereditary neuralgic amyotrophy families. We evaluated a family with six affected members from three generations with a point mutation in the SEPT9 gene. One of the patients presented in the neonatal period with vocal cord paralysis necessitating intubation and prolonged ventilation. The neonatal presentation of vocal cord paralysis broadens the phenotypic spectrum of hereditary neuralgic amyotrophy. The identification of a SEPT9 mutation in a neonate with respiratory distress due to vocal cord paralysis expands the differential diagnosis in these patients.

Novel mutation in VCP gene causes atypical amyotrophic lateral sclerosis

OBJECTIVE

To identify the genetic variant that causes autosomal dominantly inherited motor neuron disease in a 4-generation Israeli-Arab family using genetic linkage and whole exome sequencing.

METHODS

Genetic linkage analysis was performed in this family using Illumina single nucleotide polymorphism chips. Whole exome sequencing was then undertaken on DNA samples from 2 affected family members using an Illumina 2000 HiSeq platform in pursuit of potentially pathogenic genetic variants that comigrate with the disease in this pedigree. Variants meeting these criteria were then screened in all affected individuals.

RESULTS

A novel mutation (p.R191G) in the valosin-containing protein (VCP) gene was identified in the index family. Direct sequencing of the VCP gene in a panel of DNA from 274 unrelated individuals with familial amyotrophic lateral sclerosis (FALS) revealed 5 additional mutations. Among them, 2 were previously identified in pedigrees with a constellation of inclusion body myopathy with Paget disease of the bone and frontotemporal dementia (IBMPFD) and in FALS, and 2 other mutations (p.R159C and p.R155C) in IBMPFD alone. We did not detect VCP gene mutations in DNA from 178 cases of sporadic amyotrophic lateral sclerosis.

CONCLUSIONS

We report a novel VCP mutation identified in an amyotrophic lateral sclerosis family (p.R191G) with atypical clinical features. In our experience, VCP mutations arise in approximately 1.5% of FALS cases. Our study supports the view that motor neuron disease is part of the clinical spectrum of VCP-associated disease.

Clinical and genetic findings in eight Israeli patients with transthyretin-associated familial amyloid polyneuropathy

BACKGROUND

Transthyretin (TTR)-associated familial amyloid polyneuropathy (FAP) is an autosomal dominant multisystem disease with neurological and extra-neurological manifestations. It is caused by various mutations in the TTR gene leading to the formation of insoluble amyloid.

OBJECTIVES

To describe the clinical and genetic findings in patients with TTR-associated FAP in Israel.

METHODS

We evaluated eight patients clinically and genetically during the years 2006 to 2011.

RESULTS

At onset, all the patients exhibited sensory loss of the lower and upper limbs, five patients experienced muscle pain, and one patient had lower limb weakness. Five patients had autonomic nervous system manifestations, and four demonstrated evidence of amyloid cardiomyopathy. Nerve conduction studies showed sensorimotoraxonal neuropathy in all patients. Sural nerve biopsies were obtained in five patients; only three biopsies revealed amyloid deposit. In four patients of Yemenite descent, genetic analysis of the TTR gene demonstrated ser77tyr mutation. One patient of Tunisian descent and one Ashkenazi patient harbored the val30met mutation. One patient of Iranian descent showed val32ala mutation, and another Ashkenazi patient showed phe33leu mutation.

CONCLUSIONS

TTR-associated FAP is a progressive and fatal disease that exists in the Israeli population and is unproportionally common among Yemenite Jews. This disease may be under-diagnosed and should be considered in the differential diagnosis of any patient with rapidly progressive neuropathy, especially with autonomic involvement or extra-neural features. The absence of amyloid in nerve biopsy should not rule out the diagnosis.

McArdle disease: a novel mutation in Jewish families from the Caucasus region

McArdle disease is caused by a myophosphorylase deficiency consequent to defects in the PYGM gene. A minority of the over-133 known mutations are associated with ethnicity, occurring mainly in patients from western Europe, the United States, and Japan. We identified a novel mutation, c.632delG, in three unrelated families of Jewish descent originating from the Caucasus region. This possibly ethnicity-associated mutation can significantly facilitate the diagnosis in Jews of the Caucasus and contribute to genetic consultations.

Neonatal seizures associated with a severe neonatal myoclonus like dyskinesia due to a familial KCNQ2 gene mutation

Mutations in the potassium channel gene KCNQ2, usually cause benign familial neonatal epilepsy. This is an autosomal dominant disorder characterized by clusters of seizures occurring in the first days of life. Most patients have normal psychomotor development and spontaneous remission of seizures by 12 months of age. Since Rett and Teubel reported the first family in 1964 and the identification of KCNQ2 gene mutations in this family by Zimprich et al. in 2006, phenotypic variability has been recognized including: later onset of seizures, myokymia in isolation or accompanied by seizures, neurological deficit and mental retardation. We report a mother and son with an atypical presentation of familial neonatal epilepsy. The mother has persistent epilepsy and subnormal intelligence. The son developed a severe dyskinesia clinically compatible with multifocal myoclonus in the neonatal period that only responded to carbamazepine. He also has ataxia and delayed psychomotor development. EMG revealed a spontaneous occurrence of repetitive normal motor potentials in different muscle groups. Genetic analysis identified a heterozygous missense mutation in KCNQ2 in the child and his mother.

CONCLUSION

KCNQ2 mutations can present with a neonatal onset multifocal myoclonus-like dyskinesia.

Clinical, electrophysiologic and pathologic findings in 10 patients with myotonic dystrophy 2

BACKGROUND

Myotonic dystrophy type 2 (DM2) is an autosomal dominant, multisystem disorder caused by a CCTG tetranucleotide repeat expansion located in intron 1 of the zinc finger protein 9 gene (ZNF9 gene) on chromosome 3q 21.3.

OBJECTIVES

To describe the clinical, electrophysiologic and pathologic findings in patients with myotonic dystrophy 2.

METHODS

We evaluated 10 patients genetically, clinically and electrophysiologically during the years 2007 to 2008.

RESULTS

All patients were of Jewish European ancestry. Among affected individuals, eight patients had symptoms of proximal muscle weakness, two had muscle pain, and two exhibited myotonia. On physical examination six patients had severe weakness of hip flexor muscles. Seven individuals underwent cataract surgery, and cardiac involvement was seen in one case. On the initial electromyographic (EMG) examination five patients demonstrated myotonic discharges; repeated studies showed these discharges in nine cases. Six muscle biopsies showed non-specific pathological changes. Seven patients had an affected first-degree relative with either a diagnosed or an undiagnosed muscular disorder consistent with an autosomal dominant trait.

CONCLUSIONS

DM2 may often present with proximal muscle weakness without myotonia. EMG may initially fail to show myotonic discharges, but these discharges may eventually show in most cases on repeated EMG. Thus, DM2 may be underdiagnosed and should be included in the differential diagnosis of adult patients of Jewish European ancestry presenting with proximal lower limb weakness.

The proteomic profile of hereditary inclusion body myopathy

Hereditary inclusion body myopathy (HIBM) is an adult onset, slowly progressive distal and proximal myopathy. Although the causing gene, GNE, encodes for a key enzyme in the biosynthesis of sialic acid, its primary function in HIBM remains unknown. The goal of this study was to unravel new clues on the biological pathways leading to HIBM by proteomic comparison. Muscle cultures and biopsies were analyzed by two dimensional gel electrophoresis (2-DE) and the same biopsy extracts by isobaric tag for relative and absolute quantitation (iTRAQ). Proteins that were differentially expressed in all HIBM specimens versus all controls in each analysis were identified by mass spectrometry. The muscle cultures 2-DE analysis yielded 41 such proteins, while the biopsies 2-DE analysis showed 26 differentially expressed proteins. Out of the 400 proteins identified in biopsies by iTRAQ, 41 showed altered expression. In spite of the different nature of specimens (muscle primary cultures versus muscle biopsies) and of the different methods applied (2D gels versus iTRAQ) the differentially expressed proteins identified in each of the three analyses where related mainly to the same pathways, ubiquitination, stress response and mitochondrial processes, but the most robust cluster (30%) was assigned to cytoskeleton and sarcomere organization. Taken together, these findings indicate a possible novel function of GNE in the muscle filamentous apparatus that could be involved in the pathogenesis of HIBM.

Chronic non-paroxysmal neuropathic pain - Novel phenotype of mutation in the sodium channel SCN9A gene

BACKGROUND

Gain-of-function mutations in the SCN9A gene (encoding to NaV1.7 voltage-gated sodium channel) cause two rare paroxysmal pain disorders: inherited erythromelalgia (IEM) and paroxysmal extreme pain disorder (PEDP). These phenotypes are characterized by episodic extreme localized pain with cutaneous autonomic signs. So far, no other phenotypes have been associated with mutation in the SCN9A gene.

OBJECTIVE

To investigate mutations in the SCN9A gene in patients with chronic non-paroxysmal neuropathic pain.

PATIENTS

9 patients with chronic severe unexplained neuropathic pain.

RESULTS

Of the nine patients one had predicted pathologic mutations in the SCN9A gene. This patient had a heterozygous change of n.4648 T-C in exon 27 resulting in a substitution of W1550R, a highly conserved amino acid, predicting damage in the transmembrane S2 region, repeat IV. This mutation was not found in 50 controls.

CONCLUSIONS

SCN9A mutations cause pain syndromes other than IEM and PEPD. These mutations should be considered in patients with resistant unexplained chronic neuropathic pain.

Prevalence of central nervous system diseases--a large retrospective cohort study of adolescents

At age sixteen, most Israeli nationals must undergo medical evaluation for compulsory military duty. All potential conscripts are referred to the Israel Defense Forces (IDF) recruiting office. Therefore, medical screening of a vast number of adolescents is performed, offering a unique opportunity to study the prevalence of neurological diseases in an entire age cohort. Hence, screening is not affected by diagnostic or methodological bias. We performed a retrospective neuroepidemiological large cohort study of adolescents from the database of the Israel Defense Forces recruiting office during the years 1998-2002. The survey included 409 492 adolescents, among them 162 079 (39.5%) females. The most prevalent diagnoses were: headache (754 per 10 000 adolescents), permanent brain damage (197 per 10 000), epilepsy (167 per 10 000) and movement and coordination disorders (36 per 10 000). These were followed by cranial nerve disorders, sleep disorders, cranio-spinal bone defects, and chronic progressive CNS disorders. The relative risk for male adolescents within the specific disease groups was higher for movement-coordination, sleep and cranial nerve disorders. Multivariate analysis revealed gender and severity prevalence and sex-grade, or year-grade interactions in the distinct groups of diseases. This study provides important information on the prevalence of neurological diseases in adolescents and demonstrates some significant epidemiological trends.

Long-term glutamate supplementation failed to protect against peripheral neurotoxicity of paclitaxel

Toxic peripheral neuropathy is still a significant limiting factor for chemotherapy with paclitaxel (PAC), although glutamate and its closely related amino acid glutamine were claimed to ameliorate PAC neurotoxicity. This pilot trial aimed to evaluate the role of glutamate supplementation for preventing PAC-induced peripheral neuropathy in a randomized, placebo-controlled, double-blinded clinical and electro-diagnostic study. Forty-three ovarian cancer patients were available for analysis following six cycles of the same PAC-containing regimen: 23 had been supplemented by glutamate all along the treatment period, at a daily dose of three times 500 mg (group G), and 20 had received a placebo (group P). Patients were evaluated by neurological examinations, questionnaires and sensory-motor nerve conduction studies. There was no significant difference in the frequency of signs or symptoms between the two groups although neurotoxicity symptoms presented mostly with lower scores of severity in group G. However, this difference reached statistical significance only with regard to reported pain sensation (P = 0.011). Also the frequency of abnormal electro-diagnostic findings showed similarity between the two groups (G: 7/23 = 30.4%; P: 6/20 = 30%). This pilot study leads to the conclusion that glutamate supplementation at the chosen regimen fails to protect against peripheral neurotoxicity of PAC.

Treatment of status epilepticus and acute repetitive seizures with i.v. valproic acid vs phenytoin

OBJECTIVE

To evaluate the efficacy and tolerability of the treatment with valproic acid (VPA) in patients with status epilepticus (SE) or acute repetitive seizures (ARS) comparing it with phenytoin (PHT) treatment.

MATERIALS AND METHODS

Patients with SE or ARS were treated in a consecutive manner with either VPA or PHT intravenously. The primary endpoint was defined as clinical seizure cessation; the secondary endpoint was evaluation of drug tolerability.

RESULTS

Seventy-four adult patients with SE or ARS participated in the study, 49 with VPA i.v. and 25 PHT i.v. In 43 (87.8%) of the VPA patients, the seizures discontinued, and no rescue medication was needed. Similar results were found in the PHT group in which seizures of 22 (88%) patients were well controlled. Side effects were found in 12% of the PHT group, and in none of the VPA group.

CONCLUSIONS

VPA i.v. seems to be effective and well tolerated in adult patients with SE or ARS.

Acute painful neuropathy induced by rapid correction of serum glucose levels in diabetic patients

We report on acute painful neuropathy following reduction of high serum glucose levels in six diabetic patients, aged 27-52 (5 males). Initial glucose levels ranging between 270 and 600 mg/dL decreased to 60-160 mg/dL following insulin, pharmacologic or dietary treatment. Four patients had long-standing untreated diabetes (3-5 years). All six patients experienced severe excruciating neuropathic pain 2-4 weeks after initiation of treatment. Pain was generalized in all, starting in the feet in 4 cases. Pain intensity prompted the use of combination therapy with various anti-neuropathic pain agents. Symptoms gradually improved in all patients, allowing discontinuation of symptomatic therapy within 3-8 months. We conclude that acute painful neuropathy can complicate the correction of high glucose levels in diabetic patients. Therefore, careful correction of glucose levels should be considered in patients with long-standing uncontrolled diabetes.

Lamotrigine and catamenial epilepsy

Catamenial epilepsy (CE) is characterized by epileptic seizures in the female occurring rhythmatically with the menstrual cycle. Hormonal mechanisms have been proposed as a cause of this epileptic form. Few reports about the efficacy of anti-epileptic drugs (AEDs) have been published. We studied prospectively women with CE who were treated with lamotrigine (LTG) for a period of 3 months in order to evaluate its efficacy, measuring the progesterone levels before and after LTG at the same time. LTG seemed to be efficacious in 66% of women, meaning the disappearance of seizures or reduction of 50% or more of the number of seizures. The reported side effects were few and mild, and the drug was well tolerated. Serum progesterone levels were found to rise during LTG treatment.

Steroid-responsive myopathy: immune-mediated necrotizing myopathy or polymyositis without inflammation?

OBJECTIVE

To describe the clinical course and steroid responsiveness of a patient with subacute proximal symmetric weakness, very high serum creatine kinase activity, and myopathic pattern with fibrillations in the electromyogram, whose muscle biopsy showed necrotizing myopathy, with practically no inflammation.

DESIGN

Case report.

SETTING

Academic research.

RESULTS

Diagnosis of muscular dystrophy was suggested; nevertheless, steroid treatment was initiated, and the patient recovered and gained normal strength. However, after a few years he stopped treatment, and all symptoms recurred. He developed severe proximal weakness of all limbs. Another biopsy showed similar findings, with no inflammation; still, he responded favorably to steroids and immunosuppressive medications. Currently on a low dose of prednisone and methotrexate, he has no neurological deficit.

CONCLUSION

The absence of inflammation in muscle biopsy may lead to misdiagnosis of muscular dystrophy; however, if the clinical impression is that of inflammatory myopathy, an immunomodulatory treatment should be initiated. During the past century, there has been much controversy about the diagnosis of polymyositis (PM). The debate is still ongoing. We present hereby a patient with typical course and clinical features of PM who underwent two muscle biopsies, several years apart, which showed necrotizing myopathy, practically without inflammation, leading to misdiagnosis of muscular dystrophy. This report brings up the dispute regarding the role of muscle biopsy in the diagnosis of PM.

Minocycline treatment in acute stroke: an open-label, evaluator-blinded study

BACKGROUND

Ischemic animal model studies have shown a neuroprotective effect of minocycline.

OBJECTIVE

To analyze the effect of minocycline treatment in human acute ischemic stroke.

METHODS

We performed an open-label, evaluator-blinded study. Minocycline at a dosage of 200 mg was administered orally for 5 days. The therapeutic window of time was 6 to 24 hours after onset of stroke. Data from NIH Stroke Scale (NIHSS), modified Rankin Scale (mRS), and Barthel Index (BI) were evaluated. The primary objective was to compare changes from baseline to day 90 in NIHSS in the minocycline group vs placebo.

RESULTS

One hundred fifty-two patients were included in the study. Seventy-four patients received minocycline treatment, and 77 received placebo. NIHSS and mRS were significantly lower and BI scores were significantly higher in minocycline-treated patients. This pattern was already apparent on day 7 and day 30 of follow-up. Deaths, myocardial infarctions, recurrent strokes, and hemorrhagic transformations during follow-up did not differ by treatment group.

CONCLUSIONS

Patients with acute stroke had significantly better outcome with minocycline treatment compared with placebo. The findings suggest a potential benefit of minocycline in acute ischemic stroke.

Dysferlinopathy in the Jews of the Caucasus: a frequent mutation in the dysferlin gene

Dysferlin encoding gene (DYS) is mutated in the autosomal recessive disorders Miyoshi myopathy, Limb Girdle Muscular Dystrophy type 2B (LGMD2B) and distal anterior compartment myopathy, causing dysferlin deficiency in muscle biopsy. Three ethnic clusters have previously been described in Dysferlinopathy: the Libyan Jewish population originating in the area of Tripoli, Italian and Spanish populations. We report another cluster of this muscular dystrophy in Israel among Jews of the Caucasus region. A genomic analysis of the dysferlin coding sequence performed in patients from this ethnic group, who demonstrated an absence of dysferlin expression in muscle biopsy, revealed a homozygous frameshift mutation of G deletion at codon 927 (2779delG) predicting a truncated protein and a complete loss of functional protein. The possible existence of a founder effect is strengthened by our finding of a 4% carrier frequency in this community. These findings are important for genetic counseling and also enable a molecular diagnosis of LGMD2B in Jews of the Caucasus region.

The Effect of Duloxetine on Primary Pain Symptoms in Parkinson Disease

OBJECTIVES

To study the effect of duloxetine (Cymbalta), a selective serotonin and norepinephrine reuptake inhibitor, on pain symptoms in Parkinson Disease (PD).

METHODS/PATIENTS

Twenty-three patients with PD with painful phenomena were treated with duloxetine for 6 weeks in an open-label design. Assessments were performed before and at treatment completion and consisted of a Visual Analogue Scale, the Brief Pain Inventory, Short-Form McGill Pain Questionnaire, Parkinson Disease Quality of Life Questionnaire-39-item version, and motor part of the Unified Parkinson Disease Rating Scale. Pain threshold was assessed by quantitative sensory tests.

RESULTS

Thirteen of the 20 patients who completed the study reported varying degrees of pain relief. The mean Visual Analogue Scale, Brief Pain Inventory, and Short-Form McGill Pain Questionnaire scores decreased significantly. There was no change in pain threshold after treatment.

CONCLUSIONS

Duloxetine seems to be effective for the treatment of central pain in PD.

Monotherapy of Lamotrigine Versus Carbamazepine in Patients With Poststroke Seizure

OBJECTIVES

The incidence of seizures is known to be high in the elderly. The most common cause of an unprovoked seizure in the elderly population is stroke. These patients require effective and well-tolerated antiepileptic treatment because they frequently experience other medical conditions and use other medications that can interact with the antiepileptic treatment. The aim of the study was to analyze the tolerability and efficacy of lamotrigine (LTG) versus sustained-release carbamazepine (CBZ) treatment in newly diagnosed symptomatic poststroke seizure.

METHODS

Sixty-four patients with a first post episode of seizures were randomized in a 1:1 ratio to either LTG or CBZ treatment and were followed up prospectively for up to 12 months for efficacy and tolerability of the drugs.

RESULTS

More patients in the LTG group were seizure-free (72%) versus those in the CBZ group (44%; P = 0.06), but the numbers did not reach statistical significance because of a relative small number of study patients. The number of patients who withdraw from the study because of adverse events was statistically significantly less in the LTG group (3%) compared with the CBZ group (31%; P = 0.02).

CONCLUSIONS

The LTG treatment in poststroke seizures versus CBZ treatment is a relatively better-tolerated drug and can be acceptable as initial treatment in this specific group of patients.

Evaluation of cutaneous autonomic innervation in idiopathic sensory small-fiber neuropathy

To evaluate the loss of autonomic nerve fibers in patients with clinical pure small-fiber sensory neuropathy, we performed skin punch biopsies in 17 and 15 age- and sex-matched controls. Biopsies were taken 10 cm above the lateral malleolus, and 5-mum sections were stained with hematoxylin and eosin and the panaxonal marker protein gene product (PGP) 9.5. Positively stained fibers, represented as dots, innervating the erector pili muscles, arterioles, and sweat glands (SG) were counted. The ratios between the number of nerve fibers and nuclei of each structure were calculated. The autonomic innervation was significantly reduced in the patients' group compared with controls in all the examined autonomic-innervated structures: SG (0.27 +/- 0.15 vs. 0.66 +/- 0.37, p = 0.001), arterioles (0.38 +/- 0.32 vs. 0.86 +/- 0.45, p=0.002), and the erector pili muscle (0.58 +/- 0.27 vs. 1.23 +/- 0.87, p = 0.036). Our results suggest that autonomic involvement occurs in patients with sensory small-fiber neuropathy and that punch skin biopsy using thin sections is a simple and convenient method to detect these dermal autonomic small-fiber abnormalities.

Clinical Correlates of Occipital Intermittent Rhythmic Delta Activity (OIRDA) in Children

PURPOSE

The clinical significance of occipital intermittent rhythmic delta activity (OIRDA) on the electroencephalogram has not been fully established. Recent studies suggest that this pattern occurs almost exclusively in children and is probably of epileptic origin in most cases. We sought to characterize the electrographic features and clinical correlates of occipital intermittent rhythmic delta activity.

METHODS

A review of 697 consecutive pediatric electroencephalograms detected occipital intermittent rhythmic delta activity in 24 studies. Mean patient age was 7.96 years.

RESULTS

Recent convulsions and absence seizures constituted the main indications for the study. Concomitant, independent epileptiform activity was noted in half of the cases. This activity was focal in all but one case. Conversely, in most cases of absence seizures, epileptiform activity intermixed with occipital intermittent rhythmic delta activity. Furthermore, the frequency of the occipital rhythmic discharges in studies of children with absences was generally faster (3-4 Hz) than in localization-related epilepsy (2-3 Hz). Most patients were awake when occipital intermittent rhythmic delta activity occurred. Chronic encephalopathy was seen in one child only. Analysis of neuroimaging studies in eight cases revealed no structural pathology associated with occipital intermittent rhythmic delta activity.

CONCLUSIONS

Occipital intermittent rhythmic delta activity is probably an epileptiform pattern, although it is noted occasionally in encephalopathic children. Its electrographic characteristics appear to differ between localization-related epilepsy and primary generalized epilepsy, particularly absence seizures.

Cervical paraspinal electromyography: normal values in 100 control subjects

The normal electromyographic values and the significance of spontaneous activity, when examining the cervical paraspinal muscles, has been studied rarely, and there are very few studies concerning this issue. To obtain muscle unit potential (MUP) reference values for cervical paraspinal muscles, we examined 100 volunteers. Spontaneous activity and the analysis of 20 MUPs in every individual were checked by the automated MUP analysis program. In those individuals ages 20 to 40 years, no spontaneous activity was observed, and in the ones ages 40 to 60 years and 60 years or older, fibrillations and/or positive sharp waves were seen in 8% and 92%, respectively. MUP values were found to be close to those of upper limb muscles. Age has no significant effect on MUP values, except for mean amplitude that was increased in individuals ages 60 to 80 years.Our findings suggest that fibrillations and positive sharp waves do not have much electrodiagnostic value in the study of cervical paraspinal muscles of middle-aged and elderly subjects, when it is an isolated finding, and there is a need for an extended electromyographic examination, including other muscles, to exclude radiculopathy. Automated MUP analysis is easily performed, and our results may serve as reference values.

Acute heroin-related neuropathy

Heroin-related peripheral nervous injury has scarcely been reported, mostly as compressive neuropathy. Rarely, other types of peripheral nervous system (PNS) injury have been recognized, such as plexopathy, polyradiculopathy, mononeuropathy, and rhabdomyolysis. These complications are usually not related to local trauma, but the nature of nerve injury remains unknown. Immunologic mechanisms have been proposed, although generally there is no laboratory evidence of inflammation and usually there is no improvement following steroid therapy. We describe six patients who developed acute PNS injury following intravenous or intranasal heroin self-administration with no evidence of compression injury or inflammation. Four patients had plexopathy (two lumbosacral and two brachial), and two had symmetric distal axonal sensorimotor neuropathy affecting the lower extremities. Of the six patients, five had concomitant rhabdomyolysis (creatine kinase, CK: 5,000-100,000 U/l) and one patient with brachial plexopathy had normal CK levels. The neurological deficit was noticed 3-36 h after heroin administration. Electromyography in five patients was consistent with sensorimotor axonal loss either confined to the affected plexus or with a diffuse distribution in the legs in the two patients with neuropathy. We propose that a toxic mechanism may be responsible for non-compression cases of acute neuropathy following heroin abuse.

Skin biopsy for assessment of autonomic denervation in Parkinson's disease

Autonomic dysfunction in Parkinson's disease (PD) is considered a late complication of the disease or an adverse effect of anti-parkinsonian medications. Morphological changes are demonstrated only by postmortem examination. The study objective was to evaluate peripheral autonomic neural involvement in PD using punch skin biopsy. The study sample included 22 patients (mean age 50 +/- 7.7 years, mean disease duration 5.3 +/- 3.8 years) and 19 controls. Four-millimeter skin biopsies were immunohistochemically stained with anti-PGP 9.5 antibody. Autonomic innervation of the blood vessels, sweat glands, and erector pili muscles was assessed and rated from 0 (normal) to 2 (severe). Cutaneous autonomic innervation was decreased in patients compared to controls. Semi quantitative analysis demonstrated reduced autonomic innervation of the blood vessels (1.0 +/- 0.8 vs. 0.42 +/- 0.8 in controls; p < 0.02), of sweat glands (0.95 +/- 0.67 vs. 0.47 +/- 0.61; p < 0.02) and of the erector pili muscles (1.06 +/- 0.55 vs 0.21 +/- 0.42; p < 0.001). This method demonstrates that the peripheral autonomic system is affected in PD at early stage of the disease and that autonomic involvement in PD may be more prevalent than previously thought.

A benign congenital myopathy in an inbred Samaritan family

We describe a novel form of myopathy in a mother and her two daughters from an inbred Samaritan family. The patients displayed severe neonatal hypotonia, lethargy and dysmorphic features. Motor milestones were delayed; however, the hypotonia and muscle weakness gradually improved during the first 2 years of life and independent walking was achieved by 18 months. The mother at the age of 23 years shows myopathic facies and minimal proximal weakness. Her intelligence is normal. Her muscle biopsy revealed central nuclei and disruption of the intermyofibrillary network with moth eaten and spiral fibers. Mutations in SMN, MTM1 and the myotonic dystrophy genes were excluded. We suggest this is a new benign form of congenital myopathy. Inheritance is probably autosomal recessive.

Acute steroid responsive small-fiber sensory neuropathy: a new entity?

Small-fiber neuropathy is often idiopathic and commonly follows a chronic course. Treatment is often effective in treating the core symptom of pain, but it has no effect on the pathologic process. We describe four patients with acute small-fiber neuropathy who responded dramatically to steroid therapy. All patients had acute onset neuropathic pain, normal nerve conduction studies, and evidence of small-fiber dysfunction in quantitative sensory testing and skin biopsy. Symptoms were distal and symmetrical in three patients and generalized in one patient. In two cases, the neuropathy presented as an erythromelalgia-like syndrome. Marked clinical improvement occurred 1-2 weeks after oral prednisone therapy was initiated. Three patients remained symptom free, and one patient experienced recurrence of neuropathy after prednisone was tapered.

Asymptomatic or minimally symptomatic hyperCKemia: histopathologic correlates

BACKGROUND

Persistent creatine kinase elevation is occasionally encountered in subjects without any clinical manifestation of a neuromuscular disorder or any condition known to be associated with increased serum CK levels. It is still unresolved whether extensive investigations and specifically a muscle biopsy should be performed in clinically normal individuals with elevated CK levels.

OBJECTIVE

To study the muscle pathology of patients with asymptomatic or minimally symptomatic hyperCKemia.

METHODS

The clinical and laboratory data of patients with persistent hyperCKemia and normal neurologic examination were reviewed and their muscle biopsies evaluated.

RESULTS

The study group included 40 patients aged 7-67 years; the male to female ratio was 3:1. Nineteen patients were completely asymptomatic, 20 had mild non-specific myalgia, and 1 had muscle cramps. Electromyography was performed in 27 patients and showed myopathic changes in 7 (26%). Abnormal muscle biopsy findings (e.g., increased variation in fiber size, increased number of central nuclei, and occasional degenerating fibers) were detected in 22 of the 40 patients (55%). No fat or glycogen accumulation was detected. Immunohistochemistry demonstrated abnormal dystrophin staining in 3 patients (8%), resembling the pathologic changes of Becker muscular dystrophy. No abnormal findings were detected on immunohistochemical staining for merosin, dysferlin, caveolin 3, or alpha and gamma sarcoglycans. The EMG findings did not correlate with the pathologic findings.

CONCLUSIONS

Abnormal muscle biopsies were found in 55% of patients with asymptomatic or minimally symptomatic hyperCKemia. Specific diagnosis of muscular dystrophy, however, was possible in only 8% of the patients.