Search

The Brown-Vialetto-Van Laere syndrome (BVVLS) is a rare neurological disorder characterized by progressive pontobulbar palsy, sensorineural deafness and mixed spinal and upper motor neuropathy. Mutations in the C20orf54 gene have been linked to the disease and recently we reported the first Italian case of a BVVLS family with an intriguing C20orf54 genotype. However, the pathomechanisms underlying BVVLS are still unknown. Here we present the particular disease course with partial response to immunosuppressive therapy of our BVVLS patient for whom we hypothesize that dysimmune factors may have played a role in disease physiopathology.

Background Disorders of oxidative phosphorylation affects 1/5000 individuals and present heterogeneous involvement of tissues highly dependent upon ATP production. Case presentation Here we present the case of a 48-year-old woman carrying a homozygous mutation (p.A899T) in mitochondrial polymerase gamma (POLG) and manifesting with a complex neurological phenotype including Dopamine-agonist responsive Parkinsonism. Conclusion This case report is further evidence that mitochondrial dysfunction might play a role in Parkinson’s Disease pathogenesis and helps in identification of apparent mutation-specific clinical characteristics. Mutations in POLG should be looked for in cases of Parkinsonism, especially when multisystem neurological involvement is found.

Myelin sheath is the proteolipid membrane wrapping the axons of CNS and PNS. We have shown data suggesting that CNS myelin conducts oxidative phosphorylation (OXPHOS), challenging its role in limiting the axonal energy expenditure. Here, we focused on PNS myelin. Samples were: (i) isolated myelin vesicles (IMV) from sciatic nerves, (ii) mitochondria from primary Schwann cell cultures, and (iii) sciatic nerve sections, from wild type or Charcot-Marie-Tooth type 1A (CMT1A) rats. The latter used as a model of dys-demyelination. O₂ consumption and activity of OXPHOS proteins from wild type (Wt) or CMT1A sciatic nerves showed some differences. In particular, O₂ consumption by IMV from Wt and CMT1A 1-month-old rats was comparable, while it was severely impaired in IMV from adult affected animals. Mitochondria extracted from CMT1A Schwann cell did not show any dysfunction. Transmission electron microscopy studies demonstrated an increased mitochondrial density in dys-demyelinated axons, as to compensate for the loss of respiration by myelin. Confocal immunohistochemistry showed the expression of OXPHOS proteins in the myelin sheath, both in Wt and dys-demyelinated nerves. These revealed an abnormal morphology. Taken together these results support the idea that also PNS myelin conducts OXPHOS to sustain axonal function.

Our objective was to assess the incidence and trends of amyotrophic lateral sclerosis (ALS) in Liguria, a north-west region of Italy, utilizing a prospective design. Liguria (1,615,064 residents in 2010) is the site of a multicentre-multisource prospective population based registry called LIGALS (Liguria Amyotrophic Lateral Sclerosis Registry). All incident ALS cases during the period 2009-2010 were enrolled and followed up. Cases were identified using several concurrent sources. ALS diagnosis was based on the revised El Escorial criteria. One hundred and four cases were enrolled, generating an annual crude incidence of 3.22/100,000 (95% CI 2.66-3.90), with a male/female ratio of 1.34. The annual standardized incidence, age and gender adjusted to the 2001 Italian population, was 2.51. At last observation on 1 March 2012, 45% of patients registered in the LIGALS had died, with a median survival of 45 months from symptoms onset. According to capture-recapture estimation, three patients were unobserved. For both genders, demographic and clinical features were collected. In conclusion, comparing these data to those of epidemiological studies with a similar prospective design, the occurrence of ALS is similar. The observed crude incidence was higher compared to other Italian studies, due in part to a very careful case ascertainment and in part to a high percentage of the elderly in Liguria.

Pain is a subjective condition that cannot be objectively measured; for this reason, self patient-perspective is crucial. Recently, several screening tools to discriminate between nociceptive and neuropathic pain have been developed. We aimed at assessing the consistence and discrepancy of two widely used screening tools, The Douleur Neuropathique 4 (DN4) and the 6-item questionnaire (ID-Pain), by comparing their ability in discriminating neuropathic from nociceptive pain. DN4 and ID-Pain were administered to 392 Italian patients attending 16 outpatient services for peripheral nerve diseases. Based on medical history, clinical findings and diagnostic tools, patients were divided into two groups (neuropathic and nociceptive). Globally, ID-Pain identified neuropathic pain in 60 % of patients (38 % probable, 22 % likely). Interestingly also DN4 diagnosed neuropathic pain in 60 % of cases. A discrepancy was observed in 16 % of cases. DN4 and ID-Pain resulted to be highly interrelated in the identification of neuropathic pain. Sensitivity of DN4 was 82 % and specificity was 81 %, while ID-Pain (considering both probable and likely groups) showed sensitivity 78 % and specificity 74 %. Reliable screening tools for neuropathic pain are well related between them; hence, they are available for researchers and clinicians who may choose the most appropriate for their activity. Since the gold standard for the diagnosis and treatment of neuropathic pain cannot do without a neurological evaluation, perhaps DN4, that includes physician objective measures, may help reducing the percentage of dubious cases. Conversely, when needing a more agile tool (not needing a physician) ID-Pain may be adopted.

We report the first case of a missense mutation in MPZ causing a gain of glycosylation in myelin protein zero, the main protein of peripheral nervous system myelin. The patient was affected by a severe demyelinating neuropathy caused by a missense mutation, D32N, that created a new glycosylation sequence. We confirmed that the mutant protein is hyperglycosylated, is partially retained into the Golgi apparatus in vitro, and disrupts intercellular adhesion. By sequential experiments, we demonstrated that hyperglycosylation is the main mechanism of this mutation. Gain of glycosylation is a new mechanism in Charcot-Marie-Tooth type 1B.

Background Tafamidis is a transthyretin (TTR) stabilizer able to prevent mutated TTR tetramer dissociation into amyloidogenic monomers. There have been a few encouraging studies on safety and long-term efficacy of Tafamidis in early-onset Val30Met TTR-familial amyloid polyneuropathy (TTR-FAP) patients. However, less is known about its efficacy in later stages of the disease and in non-Val30Met mutations.

Inherited peripheral neuropathies are among the most common hereditary diseases of the nervous system. Charcot-Marie-Tooth (CMT) disease, also known from previous classifications as hereditary motor and sensory neuropathy (HMSN), is certainly the most common inherited neuropathy. In the past several years, various treatments for CMT have been proposed, although specific therapies are not yet available. In clinical practice, rehabilitative strategies remain the most helpful therapeutic approach to these patients. There is still a lack of consensus on the best way to rehabilitate patients affected by CMT. Based on our personal experience and on a review of the literature, we first recommend the prescription of ankle-foot orthoses (AFO) for patients affected by CMT; the choice of which patient, which AFO, and when to apply it depends on the individual condition of each patient and on the experience of the physician/therapist. Second, adaptive equipment (eg, button hook, long-handled shoehorn, elastic shoe laces) is available to compensate for hand deformities, sensory loss, and weakness. Third, moderate to intense strength training and aerobic exercise are well tolerated by patients affected by CMT; further studies are needed to establish whether these approaches are effective in improving their motor function and strength. There is not enough evidence to recommend muscle stretching exercises or proprioceptive kinesiotherapy, although in our experience both approaches may be helpful in selected CMT patients to prevent tendon retractions, muscle tightening, and loss of strength, and to improve balance. There is growing knowledge of the underlying genetic defects and molecular pathophysiology in CMT. To date, only a few clinical trials in CMT patients have been performed. A neurotrophic factor, neurotrophin 3, was used in a small sample of CMT1A patients with promising results, but it has not been tested in a larger cohort and there is currently no reason to suggest this therapy for CMT1A neuropathy. Based on positive results in an animal model of CMT1A, three trials with ascorbic acid (AA) were completed in a large number of patients with this neuropathy, with results that were negative overall. Therefore, it is not possible to recommend the use of AA in CMT1A patients at this time, but the results of a larger Italian-UK study and an American trial with higher doses of AA are still awaited. It is important to remember that a superimposed inflammatory/disimmune process may complicate the course of the neuropathy; in this case, severe worsening (especially motor) in a matter of weeks or months is a "red flag" that should suggest immunosuppressive or immunomodulatory treatment such as steroids, intravenous immunoglobulin, or plasma exchange. In fact, steroid-sensitive cases of HMSN were described many years ago, well before the genetic diagnosis was available. Symptomatic treatment to reduce neuropathic and nociceptive pain, both of which have been reported in patients affected by CMT, should be prescribed according to recently published guidelines for the therapy of pain. No evidence suggests any specific surgical intervention or change in diet or lifestyle for patients affected by various types of CMT.

We evaluated the sensitivity of various rehabilitation and lung function scales to detect differences between people with Charcot-Marie-Tooth (CMT) disease and healthy controls. We also studied whether these measurements are sensitive to disclose changes in patients with CMT disease after rehabilitative treatment.: Eight patients with different types of CMT participated in the study. Data were gathered at baseline; at the end of the treadmill training, stretching, respiratory, and proprioceptive exercise (TreSPE) treatment period; and after a washout period of 6 mos. The following instruments were used for data collection: Medical Research Council scale for lower limb strength; Tinetti Balance Scale; Physical Performance Battery; ankle angle, oxygen consumption, and lung function tests; peak treadmill velocity and slope; time to walk 6 m; and CMT Neuropathy Score. The participants underwent TreSPE treatment twice every week for 8 wks.: All rehabilitative measures were significantly worse in subjects with CMT disease than in healthy controls. Lung function was always normal except for the maximum expiratory pressure and maximum inspiratory pressure. No dropouts or worsening in any of the different outcome measures were observed after TreSPE. The ankle angle and the time to walk 6 m were the only measures that significantly improved after treatment.: The rehabilitative outcome measures used in this protocol are useful in detecting clinical impairment in people with CMT disease. Lung function tests were confirmed to be minimally abnormal in patients with CMT disease. The TreSPE treatment, besides being safe and well tolerated, induced some training effects in CMT neuropathy, in the absence of lung function amelioration and effort tolerance. Follow-up showed that CMT patients should be treated at least twice every year because a regression of all outcome measures to the baseline state was found after a 6-mo washout period.

Background Antimyelin-associated glycoprotein (MAG) polyneuropathy is a slowly progressive distal form of mixed motor-sensory polyneuropathy that is scarcely responsive to conventional immunosuppressive therapy. Rituximab, a B-cell depleting antibody, is a promising therapeutic choice for anti-MAG polyneuropathy, and the evaluation of factors, such as B-cell-activating factor (BAFF), that control B-cell homeostasis is important to understand how this drug works. Methods Using an ELISA method, the authors measured serum BAFF concentrations in 23 patients with anti-MAG polyneuropathy, before and after rituximab therapy, in 20 neurological controls and in 14 healthy subjects. The patients were followed up over a mean period of 38±12 months and categorised as responders/non-responders, and, between the responders, as relapsing/non-relapsing. Results Pretherapy serum BAFF concentrations in non-responders were higher than in responders (cut-off 1665 pg/ml; sensitivity 71.4%; specificity 93.7%; likelihood ratio 11.4), with the highest post-therapy increases in responders. In the responders who relapsed, relapses occurred when serum BAFF concentrations returned to baseline values, 1–2 years after blood B-cell reappearance. Conclusions Before and during therapy, measurements of serum BAFF in rituximab-treated patients with anti-MAG polyneuropathy may help predict the response to the therapy. The findings in this study also provide information about rituximab-induced modifications on B-cell homeostatic regulation.

Background A few case reports have shown controversial results of rituximab efficacy in patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Objective To analyse the efficacy of rituximab in a large CIDP cohort. Methods A retrospective, observational and multicentre study on the use of rituximab in CIDP. 13 Italian CIDP patients were treated with rituximab after the partial or complete lack of efficacy of conventional therapies. Eight patients had co-occurring haematological diseases. Patients who improved by at least two points in standard clinical scales, or who reduced or discontinued the pre-rituximab therapies, were considered as responders. Results Nine patients (seven with haematological diseases) responded to rituximab: six of them, who were non-responders to conventional therapies, improved clinically, and the other three maintained the improvement that they usually achieved with intravenous immunoglobulin or plasma exchange. Significantly associated with shorter disease duration, rituximab responses started after a median period of 2.0 months (range, 1–6) and lasted for a median period of 1 year (range, 1–5). Conclusions Rituximab seems to be a promising therapeutic choice when it targets both CIDP and co-occurring haematological diseases. Timely post-onset administration of rituximab seems to be associated with better responses.

ADP-ribosyl cyclases from both vertebrates and invertebrates were previously shown to produce two isomers of P1,P2 diadenosine 5',5'"-P1, P2-diphosphate, P18 and P24, from cyclic ADP-ribose (cADPR) and adenine. P18 and P24 are characterized by an unusual N-glycosidic linkage in one of the adenylic mononucleotides (Basile, G., Taglialatela-Scafati, O., Damonte, G., Armirotti, A., Bruzzone, S., Guida, L., Franco, L., Usai, C., Fattorusso, E., De Flora, A., and Zocchi, E. (2005) Proc. Natl. Acad. Sci. U.S.A. 102, 14509-14514). P24, but not P18, proved to increase the intracellular Ca(2+) concentration ([Ca(2+)](i)) in HeLa cells and to negatively affect mitochondrial function. Here we show that micromolar P24, but not P18, triggers a slow and sustained influx of extracellular Ca(2+) through the opening of the purinergic receptor/channel P2X7. On the other hand, P18 inhibits the Ca(2+) influx induced by 0.6 mm ATP in HEK293 cells stably transfected with P2X7, with an IC(50) of approximately 1 mum. Thus, P18 is devoid of intrinsic P2X7 stimulatory activity and behaves as an ATP antagonist. A P2X7-mediated increase of the basal [Ca(2+)](i) has been demonstrated to negatively affect Schwann cell (SC) function in rats with the inherited, peripheral neuropathy Charcot-Marie-Tooth 1A (CMT1A) (Nobbio, L., Sturla, L., Fiorese, F., Usai, C., Basile, G., Moreschi, I., Benvenuto, F., Zocchi, E., De Flora, A., Schenone, A., and Bruzzone S. (2009) J. Biol. Chem. 284, 23146-23158). Preincubation of CMT1A SC with 200 nm P18 restored the basal [Ca(2+)](i) to values similar to those recorded in wild-type SC. These results identify P18 as a new P2X7 antagonist, potentially useful in the treatment of CMT1A.

Hereditary inclusion body myopathy (IBM2) was mainly reported in Middle Eastern Jewish patients. Distal myopathy with rimmed vacuoles has been described as a worldwide distributed distal myopathy. Both diseases are caused by mutations of the UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE) gene. Herein we report two patients: an Egyptian Muslim patient with the "common" Middle Eastern mutation (M712T), rarely described in non-Jewish patients; and an Italian patient carrying a novel GNE mutation (L179F) in the epimerase domain. Our patients share common clinical and histopathological features, with some interesting aspects. The first patient presented a clinical deterioration during her first pregnancy confirming that an increased requirement of sialic acid during pregnancy may trigger a clinical worsening. The second patient showed a slowly progressive deterioration, different from other patients carrying mutations in the epimerase domain, who had a severe and rapid progression.

Neurosyphilis is still a significant medical problem in developing countries and syphilitic ocular manifestations are often not diagnosed due to the lack of typical characteristics. We describe the case of a 59-year-old homosexual man with a 1-month history of decreased vision acuity in his left eye who was diagnosed with neurosyphilis and received treatment with intravenous penicillin G (16 million units in divided daily doses), with great improvement of visual acuity and CSF examination findings. The interest of this case is not only represented by the unusually early ocular involvement, but also by the rapid evolution of the disease into the secondary stage in a man who had had one at-risk homosexual relationship only 3 months before the onset symptoms. We also support the view that the presence of ocular involvement in syphilitic patients is suggestive of involvement of the CNS and should be considered synonymous with neurosyphilis.

The aim of this study was to validate the Italian version of the Neuropathic Pain Symptom Inventory (NPSI) in patients with neuropathic pain due to peripheral nerve diseases, and also to evaluate the validity of a new NPSI score: a frequency weighted NPSI score (NPSI-FW). First, the original version of the NPSI was translated into Italian. Then the validity and reliability of the Italian NPSI (I-NPSI) were tested in 392 Italian patients consecutively referred to 16 Italian outpatient services for peripheral nerve diseases, by correlating the I-NPSI scores with other pain scales. The repeatability and responsiveness were assessed. A significant correlation between the I-NPSI scores and all the other pain measures was seen. Reproducibility and responsiveness were good. Our study shows the validity of the I-NPSI and demonstrates its reliability for assessing neuropathic pain in patients with peripheral nerve diseases. The I-NPSI scores represent reliable measurements to assess neuropathic symptoms and effectiveness of treatment on them.

We investigated the contribution of Schwann cell-derived ciliary neurotrophic factor (CNTF) to the pathogenesis of Charcot-Marie-Tooth disease type 1A (CMT1A) and addressed the question as to whether it plays a role in the development of axonal damage observed in the disease, with aging. Ciliary neurotrophic factor was underexpressed in experimental CMT1A but not in other models of hereditary neuropathies. Sciatic nerve crush experiments and dosage of CNTF at different time points showed that expression of this trophic factor remained significantly lower in CMT1A rats than in normal controls; moreover, in uninjured CMT1A sciatic nerves CNTF levels further decreased with ageing, thus paralleling the molecular signs of axonal impairment, that is increased expression of non-phosphorylated neurofilaments and amyloid precursor protein. Administration of CNTF to dorsal root ganglia cultures reduced dephosphorylation of neurofilaments in CMT1A cultures, without improving demyelination. Taken together, these results provide further evidence that the production of CNTF by Schwann cells is markedly reduced in CMT1A. Moreover, the observations suggest that trophic support to the axon is impaired in CMT1A and that further studies on the therapeutic use of trophic factors or their derivatives in experimental and human CMT1A are warranted.

Congenital hypomyelination (CH) is a hereditary demyelinating peripheral neuropathy characterized by early infancy onset, distal muscle weakness, hypotonia, areflexia, and severe slowing of nerve conduction velocities. In the present report, the clinical, morphological, and immunohistochemical features of a CH case and the identification of a mutation in the gene (MPZ) for protein zero (P0) associated with this phenotype are described. This "de novo" mutation in a patient presenting with clinical features quite distinct from those of the more frequent Charcot-Marie-Tooth type 1B disease (CMT1B) or Dejerine-Sottas syndrome (DSS) confirms that CH is allelic with other disorders characterized by a less severe phenotype and a different clinical and neuropathological profile.

Cerebrotendinous xanthomatosis (CTX) is a treatable, autosomal recessive, lipid storage disorder characterized by diarrhea and cataracts, usually appearing in the first decade of life, followed by growth of tendon xanthomas and progressive neurologic disability.1 The typical brain findings include MRI signal abnormalities mainly in the globus pallidus and dentate nuclei.2 The disease is caused by deficiency of the mitochondrial enzyme, sterol 27-hydroxylase, resulting in impaired primary bile acid synthesis, decreased chenodeoxycholic acid production, and cholestanol accumulation in virtually every tissue.3 The main blood chemistry abnormalities include high plasma levels of cholestanol with normal to low cholesterol. Different mutations of the CYP27A1 gene have been described.4 Early diagnosis is crucial as treatment with chenodeoxycholic acid (CDCA) may improve symptoms.5 Here we report the cases of two Argentinian siblings with a novel mutation of the CYP27A1 gene associated with clinical variants, including absence of tendon xanthomas. ### Case 1 (male, 17 years). The first clinical manifestation was chronic diarrhea from birth and growth retardation. Episodes of febrile seizures occurred at 1 and 3 years, followed by photosensitive epileptic syndrome. Posterior subcapsular cataracts were found at 3 years and removed at 8 years of age. Mild mental retardation, attention deficit, and hyperactivity were reported at school age. At 17 …

Charcot-Marie-Tooth type 1A (CMT1A) represents 80% of all the demyelinating hereditary motor and sensory neuropathies. As recently suggested, neuroactive steroids may have a role in a therapeutic strategy for peripheral neuropathies, including CMT1A. To this aim, an accurate qualitative and quantitative analysis of neuroactive steroid levels in this disease could be extremely important to define effective pharmacological strategies. We here analyzed by liquid chromatography-tandem mass spectrometry the levels of neuroactive steroids present in the sciatic nerve of male and female peripheral myelin protein 22 transgenic rats (PMP22(tg) rats; i.e., an experimental model of CMT1A) and of the corresponding wild-type littermates. We observed that, both in PMP22(tg) rats and in the wild types, the levels of neuroactive steroids, such as progesterone, tetrahydroprogesterone (THP), isopregnanolone (3beta,5alpha-THP), testosterone, dihydrotestosterone, and 5alpha-androstane-3alpha, 17beta-diol (3alpha-diol) are sexually dimorphic. It is interesting to note that the levels of 3beta,5alpha-THP and of 3alpha-diol, which are exclusively detectable in sciatic nerve of female and male rats, respectively, are strongly decreased in PMP22(tg) rats. 3beta,5alpha-THP and 3alpha-diol are modulators of gamma-amino butyric acid A receptor. Thus, the present findings may be considered an interesting background for experiments aimed to evaluate the possible therapeutic effects of modulators of this neurotransmitter receptor in male and female PMP22(tg) rats.

Based on clinical, neurophysiological, and neuropathological features, hereditary neuropathies are classified into hereditary motor and sensory neuropathies (HMSNs), hereditary sensory and autonomic neuropathies (HSANs), and hereditary motor neuronopathies (HMNs). HMSNs are also known as Charcot-Marie-Tooth disease (CMT) and related neuropathies are characterized by a slowly progressive, distal sensorimotor process beginning in childhood. The advancements of molecular genetics have allowed important discoveries in the field of hereditary neuropathies. At least 35 genes are known to cause inherited neuropathies, and more than 50 distinct loci are identified. The inherited peripheral neuropathies mutation database provides a comprehensive and updated list of all known mutations. Molecular and cell biology played an important role in understanding how particular mutations cause disease. A deeper knowledge of the underlying pathogenic mechanisms allows the development of therapeutic strategies for CMT neuropathies, as is happening for the 1A type of CMT, which is described in this chapter.

As experience is gained, ultrasound (US) continues to identify an increasing number of nerves and related pathologic conditions. High-resolution US provides cost-effective, accurate morphologic information regarding a variety of nerve abnormalities including inherited disorders and developmental anomalies, nerve involvement in medical diseases, entrapment syndromes, traumatic injuries, and neurogenic masses. In many of these conditions, US can significantly enhance clinical decision making regarding conservative or surgical treatment. In clinical practice, US can be considered an ideal complement to clinical and electrophysiologic testing for the diagnostic work-up of patients who have peripheral neuropathies.

Clinical progression in hereditary and acquired demyelinating disorders of both the central and peripheral nervous system is mainly due to a time-dependent axonal impairment. We established 90-day dorsal root ganglia (DRG) cultures from a rat model of Charcot-Marie-Tooth type 1A (CMT1A) neuropathy to evaluate the structure of myelin and axons, and the expression of myelin-related proteins and cytoskeletal components, by morphological and molecular techniques. Both wild-type and CMT1A cultures were rich in myelinated fibres. Affected cultures showed dysmyelinated internodes and focal myelin swellings. Furthermore, uncompacted myelin and smaller axons with increased neurofilament (NF) density were found by electron microscopy, and Western blots showed higher levels of nonphosphorylated NF. Confocal microscopy demonstrated an abnormal distribution of the myelin-associated glycoprotein which, instead of being expressed at the noncompact myelin level, showed focal accumulation along the internodes while other myelin proteins were normally distributed. These findings suggest that CMT1A DRG cultures, similarly to the animal model and human disease, undergo axonal atrophy over a period of time. This model may be utilized to study the molecular changes underlying demyelination and secondary axonal impairment. As axonal damage may occur after just 3 months and tissue cultures represent a strictly controlled environment, this model may be ideal for testing neuroprotective therapies.

Malignant forms of multiple sclerosis (MS) represent a limited group of very aggressive demyelinating diseases, which rapidly progress to severe disability leading often to life-threatening conditions. On these clinical entities, currently available therapies for MS are not very effective. Recently, it has been demonstrated that intense immunosuppression followed by autologous stem cell transplantation (ASCT) can affect the clinical course of individuals with severe MS and completely abrogate the inflammatory activity detected by magnetic resonance imaging (MRI). We report on the treatment with intense immune ablation followed by ASCT of three patients with malignant MS whose clinical course indicated a dramatically poor prognosis. This procedure succeeded in halting the rapidly worsening course of disease. The effect was long lasting, as demonstrated by a sustained efficacy over a two-year period in two subjects and 12 months in the third case. In addition, a striking effect on inflammation-related MRI findings was obtained. These results support a role for intense immunosuppression followed by ASCT as treatment in rapidly evolving malignant MS cases unresponsive to conventional therapies.

Skin biopsy is a minimally invasive procedure and has been used in the evaluation of non-myelinated, but not myelinated nerve fibres, in sensory neuropathies. We therefore evaluated myelinated nerves in skin biopsies from normal controls and patients with Charcot-Marie-Tooth (CMT) disease caused by mutations in myelin proteins. Light microscopy, electron microscopy and immunohistochemistry routinely identified myelinated dermal nerves in glabrous skin that appeared similar to myelinated fibres in sural and sciatic nerve. Myelin abnormalities were observed in all patients with CMT. Moreover, skin biopsies detected potential pathogenic abnormalities in the axolemmal molecular architecture previously undetected in human neuropathies. Finally, myelin gene expression at both mRNA and protein levels was evaluated by real-time PCR and immunoelectron microscopy. Peripheral myelin protein 22 (PMP22) was increased in CMT1A (PMP22 duplication) and decreased in patients with hereditary neuropathy with liability to pressure palsies (PMP22 deletion). Taken together, our data suggest that skin biopsy may in certain circumstances replace the more invasive sural nerve biopsy in the morphological and molecular evaluation of inherited and other demyelinating neuropathies.

Peripheral nervous system possesses both classical and non-classical steroid receptors and consequently may represent a target for the action of neuroactive steroids. The present review summarizes the state of art of this intriguing field of research reporting data which indicate that neuroactive steroids, like for instance progesterone, dihydroprogesterone, tetrahydroprogesterone, dihydrotestosterone and 3alpha-diol, stimulate the expression of two important proteins of the myelin of peripheral nerves, the glycoprotein P0 (P0) and the peripheral myelin protein 22 (PMP22). Interestingly, the mechanisms by which neuroactive steroids exert their effects involve classical steroid receptors, like for instance progesterone and androgen receptors, in case of P0 and non-classical steroid receptors, like GABA(A) receptor, in case of PMP22. Moreover, neuroactive steroids not only control the expression of these specific myelin proteins, but also influence the morphology of myelin sheaths and axons suggesting that these molecules may represent an interesting new therapeutic approach to maintain peripheral nerve integrity during neurodegenerative events.

To reveal the spectrum of genes that are modulated in Charcot-Marie-Tooth neuropathy type 1A (CMT1A), which is due to overexpression of the gene coding for the peripheral myelin protein 22 (pmp22), we performed a cDNA microarray experiment with cDNA from sciatic nerves of a rat model of the disease. In homozygous pmp22 overexpressing animals, we found a significant down-regulation of 86 genes, while only 23 known genes were up-regulated, suggesting that the increased dosage of pmp22 induces a general down-regulation of gene expression in peripheral nerve tissue. Classification of the modulated genes into functional categories leads to the identification of some pathways altered by overexpression of pmp22. In particular, a selective down-regulation of the ciliary neurotrophic factor transcript and of genes coding for proteins involved in cell cycle regulation, for cytoskeletal components and for proteins of the extracellular matrix, was observed. Cntf expression was further studied by real-time PCR and ELISA technique in pmp22 transgenic sciatic nerves, human CMT1A sural nerve biopsies, and primary cultures of transgenic Schwann cells. According to the results of cDNA microarray analysis, a down-regulation of cntf, both at the mRNA and protein level, was found in all the conditions tested. These results are relevant to reveal the molecular function of PMP22 and the pathogenic mechanism of CMT1A. In particular, finding a specific reduction of cntf expression in CMT1A Schwann cells suggests that overexpression of pmp22 significantly affects the ability of Schwann cells to offer a trophic support to the axon, which could be a factor, among other, responsible for the development of axonal atrophy in human and experimental CMT1A.

We performed differential gene expression profiling in the peripheral nervous system by comparing the transcriptome of sensory neurons with the transcriptome of lower motor neurons. Using suppression subtractive cDNA hybridization, we identified 5 anonymous transcripts with a predominant expression in sensory neurons. We determined the gene structures and predicted the functional protein domains. The 4930579P15Rik gene encodes for a novel inhibitor of protein phosphatase-1 and 9030217H17Rik was found to be the mouse gene synaptopodin. We performed in situ hybridization for all genes in mouse embryos, and found expression predominantly in the primary class of sensory neurons. Expression of 4930579P15Rik and synaptopodin was restricted to craniospinal sensory ganglia. Neither synaptopodin, nor any known family member of 4930579P15Rik, has ever been described in sensory neurons. The identification of protein domains and expression patterns allows further functional analysis of these novel genes in relation to the development and biology of sensory neurons. ispartof: Molecular and Cellular Neurosciences vol:30 issue:3 pages:316-325 ispartof: location:United States status: published

Sjogren’s syndrome associated chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) treated with autologous and subsequently allogeneic haematopoietic SCT (HSCT)

International audience; Charcot-Marie-Tooth type 1A (CMT1A) is a hereditary demyelinating neuropathy due to an increased genetic dosage of the peripheral myelin protein 22 (PMP22). The mechanisms leading from PMP22 overexpression to impairment of myelination are still unclear. We evaluated expression and processing of PMP22, viability, proliferation, migration, motility and shaping properties, and ability of forming myelin of PMP22 transgenic (PMP22(tg)) Schwann cells in culture. In basal conditions, PMP22(tg) Schwann cells, although expressing higher PMP22 levels than control ones, show normal motility, migration and shaping properties. Addition of forskolin to the media induces an additional stimulation of PMP22 expression and results in an impairment of cells migration and motility, and a reduction of cell area and perimeter. Similarly, co-culturing transgenic Schwann cells with neurons causes an altered cells differentiation and an impairment of myelin formation. In conclusion, exposure of PMP22(tg) Schwann to the axon or to axonal-mimicking stimuli significantly affects the transition of transgenic Schwann cells to the myelinating phenotype.

Two genes were identified for autosomal recessive forms of early onset Parkinson's disease: parkin and DJ-1. We describe 2 siblings with EOPD due to parkin mutations and peripheral neuropathy, which presented as neuropathy with liability to pressure palsies (HNPP) in the index case. RT-PCR experiments revealed that the parkin gene is expressed in sural nerves from both controls and patient with parkin-related disease. Our findings support the view that parkin may play a role in the peripheral nervous system.

Mutations in a gene encoding a novel protein of unknown function-the ganglioside-induced differentiation-associated protein 1 gene (GDAP1)-are associated with the autosomal recessive Charcot-Marie-Tooth disease type 4A (CMT4A).To investigate the role of GDAP1 mutations in causing autosomal recessive neuropathies in an Italian population.76 patients with severe early onset polyneuropathy and possible autosomal recessive inheritance were screened for mutations. A TG transversion (c.347 TG) at codon 116 (M116R) was detected in four affected subjects from three apparently unrelated families. All patients had early onset of disease with pronounced foot deformities and impaired walking. Neurophysiological studies showed an extremely variable expression. Sural nerve biopsies revealed signs of both de-remyelination and axonal impairment, the most prominent feature being a severe loss of larger fibres. Haplotype analysis of the GDAP1 locus demonstrated a common disease haplotype.The association of the mutation with a common haplotype suggested a common ancestor.

The clinical and neurophysiologic data from 65 patients taking thalidomide were reviewed. Thalidomide sensory neurotoxicity was found to be cumulative dose dependent but occurs only when the total dose is relatively high (>20 g). The risk of developing sensory neuropathy is around 10% below this threshold but increases with higher doses.

We report on a patient affected by ICF syndrome (immunodeficiency, centromeric instability of chromosomes 1, 9 and 16 and facial dysmorphism), who presented with slowing in mentation, mild right hemiparesis and focal motor seizures. MRI study of the brain suggested a diagnosis of progressive multifocal leukoencephalopathy (PML), which was confirmed by JC virus DNA detection on CSF by polymerase chain reaction (PCR). This is a unique case of adult infective neurological complication described in ICF Syndrome.

Growth arrest specific 3 (Gas3)/peripheral myelin protein 22 (PMP22) is a component of the compact peripheral nerve myelin, and mutations affecting gas3/PMP22 gene are responsible for a group of peripheral neuropathies in humans. We have performed in vivo imaging in order to investigate in detail the phenotype induced by Gas3/PMP22 overexpression in cultured cells. Here we show that Gas3/PMP22 triggers the accumulation of vacuoles, before the induction of cell death or of changes in cell spreading. Overexpressed Gas3/PMP22 accumulates into two distinct types of intracellular membrane compartments. Gas3/PMP2 accumulates within late endosomes close to the juxtanuclear region, whereas in the proximity of the cell periphery, it induces the formation of actin/phosphatidylinositol (4,5)-bisphosphate(PIP2)-positive large vacuoles. Gas3/PMP22-induced vacuoles do not contain transferrin receptor, but instead they trap membrane proteins that normally traffic through the ADP-ribosylation factor 6 (Arf6) endosomal compartment. Arf6 and Arf6-Q67L co-localize with Gas3/PMP22 in these vacuoles,and the dominant negative mutant of Arf6, T27N, blocks the appearance of vacuoles in response to Gas3/PMP22, but not its accumulation in the late endosomes. Finally a point mutant of Gas3/PMP22 responsible for the Charcot-Marie-Tooth 1A disease is unable to trigger the accumulation of PIP2-positive vacuoles. Altogether these results suggest that increased Gas3/PMP22 levels can alter membrane traffic of the Arf6 plasma-membrane–endosomal recycling pathway and show that, similarly to other tetraspan proteins, Gas3/PMP22 can accumulate in the late endosomes.

The observations here reported indicate that, in vivo, the expression of an important protein of peripheral myelin, the glycoprotein Po, is influenced by mifespristone (RU 38486), that is, an antagonist of progesterone (PR) and glucocorticoid (GR) receptor. In our experimental model, male rats have been treated at the first day of life with this antagonist and after repeated treatments, we have analyzed in the sciatic nerve of 20- (20d) and 30-day-old rats (30d) the mRNA and protein levels of Po. Moreover, expression of Po has also been analyzed in the sciatic nerve of animals treated during the first 30 days of postnatal life and then sacrificed at 90th day of life (90d). The results obtained have indicated that both mRNA and protein levels of Po decrease at 20d. Apparently, these effects seem to be transient because no changes are evident at the other two times of analysis. As shown by morphometric analysis, the treatment with RU 38486 is also able to induce morphological changes at the level of sciatic nerve. However, at variance to what is expected by an alteration of an important component of the myelin membranes like Po, no changes are evident at the level of the myelin compartment. On the contrary, a significant reduction of axon diameter in parallel to an increase in neurofilament (NF) density occurs since 30d. In conclusion, the present data seem to suggest that progestin and/or glucocorticoid signals are not only involved in the control of myelin compartment but also on the axon maintenance.

Charcot-Marie-Tooth 1A (CMT1A) neuropathy is caused by duplication of the peripheral myelin protein 22 (PMP22) gene, leading to protein overexpression. Although this protein has a role in regulating Schwann cell growth and peripheral myelin compaction, how altered concentrations of PMP22 impair myelination is unknown. We established dorsal root ganglia (DRG) cultures from a transgenic rat overexpressing PMP22 (PMP22tg) to study the behavior of PMP22tg Schwann cells in early stages of development and myelination. We used reverse transcriptase-polymerase chain reaction and light and electron microscopy to study PMP22 expression and myelin formation. Myelin ultrastructure was evaluated in sural nerves from CMT1A patients to compare experimental and human findings. PMP22tg DRG cultures contained a greater number of internodes devoid of myelin, in the absence of remyelination, and increased periodicity of myelin lamellae compared with normal cultures. Widening of myelin lamellae was also observed in CMT1A biopsy specimens. Our results suggest that both functions of PMP22, in regulating Schwann cell differentiation and contributing to peripheral myelin compaction, are affected by its overexpression. The presence of similar myelin abnormalities in PMP22tg cultures and human nerves emphasizes the importance of developing in vitro models of hereditary neuropathies to study their underlying pathomechanisms.

Multiple sclerosis (MS) is characterized by inflammation, demyelination and gliosis, involving the central nervous system (CNS) and commonly sparing the peripheral nervous system (PNS). Coexistence of CNS and PNS chronic demyelination has been rarely demonstrated in chronic inflammatory demyelinating polyradiculoneuropathies (CIDP) and in MS, but the occurrence of acute polyradiculoneuropathy in a patient with MS is even more unusual. We describe the case of a woman with relapsing-remitting MS who presented with an acute severe tetraparesis. Cerebrospinal fluid (CSF) examination together with neurophysiological data and sural nerve biopsy study demonstrated an axonal form of Guillain-Barre Syndrome (GBS). It remains unresolved if the association of an axonal form of GBS and MS is fortuitous or, on the contrary, is indicative of the coexistence in some individuals of common pathogenetic mechanisms.

A gene mutated in Charcot-Marie-Tooth disease type 4B (CMT4B), an autosomal recessive demyelinating neuropathy with myelin outfoldings, has been mapped on chromosome 11q22. Using a positional-cloning strategy, we identified in unrelated CMT4B patients mutations occurring in the gene MTMR2, encoding myotubularin-related protein-2, a dual specificity phosphatase (DSP).

We describe two Italian first cousins with familial amyloidotic polyneuropathy associated with transthyretin variant consisting of the substitution of alanine for glycine at codon 47 (TTR Ala-47), from a family with a history of cardiac failure. The 40-year-old patient presented with autonomic dysfunction and the 44-year-old cousin with congestive heart failure. Both developed sensorimotor and autonomic polyneuropathy. Since a similar clinical picture has been described in another Italian family, the cardiac involvement must be regarded as a salient and early feature of the TTR Ala-47 mutation.

In this study we evaluated the effect of recombinant human nerve growth factor (rhNGF) on cisplatin (CDDP)-induced sensory neuronopathy in an experimental paradigm in the rat. Young adult female Wistar rats were treated with CDDP (2 mg/kg ip twice weekly for nine times) alone or in combination with rhNGF (1 mg/kg sc on alternate days). The effect of CDDP +/- NGF treatment was evaluated with behavioral (tail-flick test) and neurophysiological (nerve conduction velocity in the tail) methods immediately after treatment and after a follow-up period of 6 weeks. Pathological and morphometrical examinations of the dorsal root ganglia (DRG) and sciatic and saphenous nerves were also performed. rhNGF treatment induced a significant reduction in the CDDP-induced decrease in nerve conduction velocity (P < 0.05), and this was associated with a significant protection against the decrease in somatic (P < 0.05), nuclear (P < 0.05), and nucleolar size (P < 0.01) caused by CDDP treatment. However, for each of the parameters examined the neuroprotection obtained with rhNGF treatment was not complete. At the follow-up examination no differences between the three groups were observed in tail-flick test and nerve conduction velocity. We conclude that rhNGF, administered according to the schedule used in this experiment, exerts a biologically significant neuroprotective effect against CDDP peripheral neurotoxicity

Charcot-Marie-Tooth disease type 4B (CMT4B) is a demyelinating autosomal recessive motor and sensory neuropathy characterised by focally folded myelin sheaths in the peripheral nerve. The CMT4B gene has been localised by homozygosity mapping and haplotype sharing in the 11q23 region. A cDNA encoding for the beta 2 subunit of the human brain sodium channel, SCN2B, has been recently assigned to the same chromosomal interval by FISH. The SCN2B gene has been considered a good candidate for CMT4B on the basis of protein homology, chromosomal localisation, and putative biological function of the coded product. In this paper, we report the genomic structure of the SCN2B gene consisting of 4 exons and 3 introns spanning a region of approximately 12 Kb. In addition, a search for mutations in patients affected with CMT4B as well as a refined physical localisation excludes SCN2B as the CMT4B gene.

Ninjurin is a protein that is up-regulated in Schwann cells and neurons after peripheral nerve injury. Its role in promoting nerve regeneration and its expression in sensory neurons of dorsal root ganglia, as well as the chromosomal localization of the ninjurin gene, makes this gene a candidate for hereditary sensory neuropathies (HSN). In the present report, the human ninjurin gene was analyzed in 17 unrelated patients with HSN type I, two patients with HSN type II, and 10 normal controls, by single strand conformation polymorphism and by direct sequencing. All three exons and splice junctions of the gene were investigated and no mutations were found in our sample of patients. Our results rule out a mutation in the translated region of the ninjurin gene as a cause of HSN type I and type II.

The PC12 cell line may be used as a model of NGF-induced neuronal differentiation. Exposure to NGF is accompanied by extension of neurites, cessation of growth and differentiation into cells resembling sympathetic neurons. In this study neurite outgrowth from PC12 cells was induced in serum-free, NGF-free medium conditions. Neurite outgrowth in serum-free conditions was abolished by exposure to anti-NGF antisera. Reverse transcription combined with polymerase chain reaction (RT-PCR) and in situ hybridization of PC12 cells in serum-free medium conditions revealed NGF transcripts. Western blot analysis of these cells revealed tyrosine phosphorylation of the high affinity NGF receptor (TrkA/gp140) and activation of a downstream signal cascade element, ERK-1/MAP kinase. NGF was also detected by a specific enzyme-linked immunoabsorbant assay (ELISA) revealing picogram levels of protein in conditioned medium and cell lysates. Survival of embryonic rat dorsal root ganglion neurons was maintained in cultures grown in this serum-free conditioned medium. This demonstrated that NGF may act as an autocrine or paracrine growth factor for PC12 cell differentiation.

The insulin-like growth factors (IGF-I, IGF-II) are polypeptides with both; growth-promoting and insulin-like metabolic activities [1]. IGFs, whose expression is considerable in the developing nervous system [2], have neurotrophic actions in motor [3], sensory [3] and sympathetic neurons [3–4]. Since these neural populations result to be damaged in diabetic neuropathy, it has been proposed that a loss of IGFs may be involved in the pathogenesis of this common complication of diabetes.