A Novel Dynamin 2 Mutation Causing Dominant Intermediate Charcot-Marie-Tooth Neuropathy: Case Report.

Dynamin 2 mutations are associated with Charcot-Marie-Tooth neuropathy. We report two siblings with a novel missense heterozygous point mutation (c.1609 G>A) in the highly conserved pleckstrin homology domain in exon 15 of Dynamin 2 presenting with progressive length-dependent sensorimotor polyneuropathy with mixed demyelinating and axonal features on electrodiagnostic studies. The previously unrecognized missense point mutation, which was inherited from their symptomatic but previously undiagnosed mother, was determined to be likely pathogenic based on a non-conservative amino acid substitution (p.Gly537Ser) that is predicted to damage secondary protein structure or function. This report emphasizes the importance of recognizing inherited neuropathies in clinical practice and evaluating suspected pathogenic gene variants initially classified to be of undetermined clinical significance in family cohorts. These cases add to the spectrum of pathogenic Dynamin 2 mutations associated with dominant-intermediate Charcot-Marie-Tooth neuropathy.

Peripheral neuropathy: Clinical pearls for making the diagnosis.

Peripheral neuropathy is a common condition that can be encountered in a multitude of clinical settings. Treatment must be tailored to the underlying cause. This article reviews various causes of peripheral neuropathy and offers recommendations for evaluating patients to determine the cause of peripheral neuropathy.

Neuron-microglia interaction induced bi-directional cytotoxicity associated with calpain activation.

Activated microglia release pro-inflammatory factors and calpain into the extracellular milieu, damaging surrounding neurons. However, mechanistic links to progressive neurodegeneration in disease such as multiple sclerosis (MS) remain obscure. We hypothesize that persistent damaged/dying neurons may also release cytotoxic factors and calpain into the media, which then activate microglia again. Thus, inflammation, neuronal damage, and microglia activation, i.e., bi-directional interaction between neurons and microglia, may be involved in the progressive neurodegeneration. We tested this hypothesis using two in vitro models: (i) the effects of soluble factors from damaged primary cortical neurons upon primary rat neurons and microglia and (ii) soluble factors released from CD3/CD28 activated peripheral blood mononuclear cells of MS patients on primary human neurons and microglia. The first model indicated that neurons due to injury with pro-inflammatory agents (IFN-γ) release soluble neurotoxic factors, including COX-2, reactive oxygen species, and calpain, thus activating microglia, which in turn released neurotoxic factors as well. This repeated microglial activation leads to persistent inflammation and neurodegeneration. The released calpain from neurons and microglia was confirmed by the use of calpain inhibitor calpeptin or SNJ-1945 as well as µ- and m-calpain knock down using the small interfering RNA (siRNA) technology. Our second model using activated peripheral blood mononuclear cells, a source of pro-inflammatory Th1/Th17 cytokines and calpain released from auto-reactive T cells, corroborated similar results in human primary cell cultures and confirmed calpain to be involved in progressive MS. These insights into reciprocal paracrine regulation of cell injury and calpain activation in the progressive phase of MS, Parkinson's disease, and other neurodegenerative diseases suggest potentially beneficial preventive and therapeutic strategies, including calpain inhibition.

Molecular Changes in Sub-lesional Muscle Following Acute Phase of Spinal Cord Injury.

To clarify the molecular changes of sublesional muscle in the acute phase of spinal cord injury (SCI), a moderately severe injury (40 g cm) was induced in the spinal cord (T10 vertebral level) of adult male Sprague-Dawley rats (injury) and compared with sham (laminectomy only). Rats were sacrificed at 48 h (acute) post injury, and gastrocnemius muscles were excised. Morphological examination revealed no significant changes in the muscle fiber diameter between the sham and injury rats. Western blot analyses performed on the visibly red, central portion of the gastrocnemius muscle showed significantly higher expression of muscle specific E3 ubiquitin ligases (muscle ring finger-1 and muscle atrophy f-box) and significantly lower expression of phosphorylated Akt-1/2/3 in the injury group compared to the sham group. Cyclooxygenase 2, tumor necrosis factor alpha (TNF-α), and caspase-1, also had a significantly higher expression in the injury group; although, the mRNA levels of TNF-α and IL-6 did not show any significant difference between the sham and injury groups. These results suggest activation of protein degradation, deactivation of protein synthesis, and development of inflammatory reaction occurring in the sublesional muscles in the acute phase of SCI before overt muscle atrophy is seen.

Spinal cord neurosarcoidosis.

BACKGROUND: Spinal cord neurosarcoidosis (SN) is problematic to diagnose because it mimics other inflammatory neurologic diseases. The authors report the clinical features of 29 SN cases. METHODS: They retrospectively reviewed the medical records of 29 histologically proven sarcoidosis patients with spinal cord involvement seen at 3 university medical centers. They collected clinical data including laboratory and radiological findings. Clinical outcomes were assessed retrospectively using the modified Rankin scale. RESULTS: The cohort included high number of African Americans (16/29, 55%). The lung and intrathoracic lymph nodes were the most common confirmatory biopsy sites (18/29, 62%), whereas the spinal cord was a relatively uncommon one (4/29, 14%). The most common presenting symptoms were lower extremity weakness and paresthesias. Thoracic segment was most frequently involved (21/27, 78%). Lesions were mostly intramedullary (22/27, 81%), although nearly half involved the leptomeninges (13/27, 48%). The average size of a lesion spanned 3.9 spine segments (range, 1-9); 17 of 22 (77%) intramedullary patients had ≥3 spine segments involved. Angiotensin-converting enzyme levels in cerebrospinal fluid were elevated in only 2 of 11 (18%) patients. All patients received glucocorticosteroids. Additional immune-modulating agents were used in 24 of 29 (83%) patients. Scores on the modified Rankin scale at the final follow-up visit were improved. CONCLUSIONS: Most SN cases were diagnosed indirectly based on extraneural tissue biopsy. Extended spinal cord lesion (≥3 spine segments) may be useful to distinguish SN from multiple sclerosis. Cerebrospinal fluid analysis was of limited value. Most patients experienced clinical improvement with immunosuppressive treatment, but many required combination therapy.

Cross-talk between IGF-1 and estrogen receptors attenuates intracellular changes in ventral spinal cord 4.1 motoneuron cells because of interferon-gamma exposure.

Insulin-like growth factor-1 (IGF-1) is a neuroprotective growth factor that promotes neuronal survival by inhibition of apoptosis. To examine whether IGF-1 exerts cytoprotective effects against extracellular inflammatory stimulation, ventral spinal cord 4.1 (VSC4.1) motoneuron cells were treated with interferon-gamma (IFN-γ). Our data demonstrated apoptotic changes, increased calpain:calpastatin and Bax:Bcl-2 ratios, and expression of apoptosis-related proteases (caspase-3 and -12) in motoneurons rendered by IFN-γ in a dose-dependent manner. Post-treatment with IGF-1 attenuated these changes. In addition, IGF-1 treatment of motoneurons exposed to IFN-γ decreased expression of inflammatory markers (cyclooxygenase-2 and nuclear factor-kappa B:inhibitor of kappa B ratio). Furthermore, IGF-1 attenuated the loss of expression of IGF-1 receptors (IGF-1Rα and IGF-1Rß) and estrogen receptors (ERα and ERß) induced by IFN-γ. To determine whether the protective effects of IGF-1 are associated with ERs, ERs antagonist ICI and selective siRNA targeted against ERα and ERß were used in VSC4.1 motoneurons. Distinctive morphological changes were observed following siRNA knockdown of ERα and ERß. In particular, apoptotic cell death assessed by TUNEL assay was enhanced in both ERα and ERß-silenced VSC4.1 motoneurons following IFN-γ and IGF-1 exposure. These results suggest that IGF-1 protects motoneurons from inflammatory insult by a mechanism involving pivotal interactions with ERα and ERß.

Neurosarcoidosis.

OPINION STATEMENT: Neurosarcoidosis can involve either the central nervous system (CNS), the peripheral nervous system (PNS), or both. The clinical manifestations are varied and include cranial neuropathy, aseptic meningitis, hydrocephalus, headache, seizure, neuropsychiatric symptoms, neuroendocrine dysfunction, myelopathy, and peripheral neuropathy. Neurologic problems that develop in sarcoidosis patients should not be assumed to represent neurosarcoidosis, as they are often attributable to another cause. The diagnostic work up of neurosarcoidosis should include an evaluation for potential extra-neural involvement and histologic confirmation of sarcoidosis. If there is no appropriate extra-neurologic organ for biopsy, a biopsy from involved neural tissue needs to be considered. Biopsy of the dura and leptomeninges is less invasive than biopsy of the brain or spinal cord parenchyma. Gadolinium-enhanced magnetic resonance imaging (MRI) of the brain and spinal cord is the most sensitive test for neurosarcoidosis, while the diagnostic specificity of cerebrospinal fluid (CSF) analysis is limited. Corticosteroids are the mainstay of treatment for neurosarcoidosis. In general, oral corticosteroids are used for mild to moderate cases, while high-dose intravenous methylprednisolone is used in severe cases or refractory cases that fail to respond to oral corticosteroids. Immunomodulating and cytotoxic agents are often required for steroid-refractory neurosarcoidosis or for patients who develop significant corticosteroid adverse effects. Methotrexate is used as a first-line corticosteroid sparing agent. Tumor necrosis factor-alpha inhibitors, including infliximab, are effective for refractory neurosarcoidosis. Cyclophosphamide is also used for refractory neurosarcoidosis patients, but, because of the drug's significant toxicity, it is usually reserved for severe cases that have failed oral therapies when tumor necrosis factor alpha antagonists cannot be obtained. In addition to anti-granulomatous therapy, treatment is frequently required for neurosarcoidosis-associated conditions, such as epilepsy and neuroendocrine dysfunction. Surgical intervention is indicated for life threatening complications such as hydrocephalus, steroid-refractory spinal cord compression, or mass lesions causing increased intracranial pressure.

Isolated neurosarcoidosis: case series in 2 sarcoidosis centers.

BACKGROUND: Neurosarcoidosis occurs in the central or peripheral nervous system and is usually associated with other sarcoidosis organ involvement. However, when sarcoidosis develops exclusively in the nervous system, its diagnosis is problematic. METHODS: Retrospective analysis of patients who were histologically diagnosed with neurosarcoidosis without other organ involvement (isolated neurosarcoidosis) at Medical University of South Carolina and Allegheny General Hospital. For comparison, we also collected data from neurosarcoidosis patients with histologic evidence in an extraneural organ (systemic neurosarcoidosis). RESULTS: Ninety-one cases of neurosarcoidosis were identified with 10 patients having isolated neurosarcoidosis. Common clinical manifestations of the isolated neurosarcoidosis patients were headache (9), paresthesia (5), and cranial neuropathies (4). All isolated neurosarcoidosis patients underwent a biopsy from the central nervous system. The prebiopsy impression included lymphoma (4), tumor (2), and sarcoidosis (2). In all patients, no extranueral sarcoidosis developed during a relatively long follow-up period (mean 58 mo). Compared with the systemic neurosarcoidosis cohort (60), isolated neurosarcoidosis patients had similar demographics and neurological manifestations with a few exceptions including a more common frequency of headache, hemiparesis, and radiculopathy, leptomeningeal involvement on brain MRI, increased cell count in cerebrospinal fluid, and a more favorable clinical outcome (P<0.05). The duration of follow-up and the number of studies performed to evaluate patients for extraneural sarcoidosis were similar in the 2 cohorts. CONCLUSIONS: The clinical and radiologic features of isolated neurosarcoidosis are similar to those of systemic neurosarcoidosis with a few exceptions. The diagnosis of isolated neurosarcoidosis is problematic and often not considered before biopsy of neural tissue.

Calpain inhibition attenuated morphological and molecular changes in skeletal muscle of experimental allergic encephalomyelitis rats.

Muscle weakness and atrophy are important manifestations of multiple sclerosis (MS). To investigate the pathophysiological mechanisms of skeletal muscle change in MS, we induced experimental autoimmune encephalomyelitis (EAE) in Lewis male rats and examined morphological and molecular changes in skeletal muscle. We also treated EAE rats with calpepetin, a calpain inhibitor, to examine its beneficial effects on skeletal muscle damage. Morphological changes in muscle tissue of EAE rats included smaller and irregularly shaped muscle fibers and fibrosis. Western blot analysis demonstrated increased calpain:calpastatin ratio, inflammation-related transcription factors (nuclear factor-κB:inhibitor of κB α ratio), and proinflammatory enzymes (cyclooxygenase-2). TUNEL-positive myonuclei in skeletal muscle cells of EAE rats indicated cell death. In addition, markers of apoptotic cell death (Bax:Bcl-2 ratio and caspase-12 protein levels) were elevated. Expression of muscle-specific ubiquitin ligases (muscle atrophy F-box and muscle ring finger protein 1), was upregulated in muscle tissue of EAE-vehicle animals. Both prophylactic and therapeutic treatment with calpeptin partially attenuated muscle changes noted in EAE animals. These results indicate that morphological and molecular changes including apoptotic cell death and protein breakdown develop in skeletal muscle of EAE animals and that these changes can be reversed by calpain inhibition.

Neurosarcoidosis: Clinical manifestations, diagnosis and treatment.

Sarcoidosis is an idiopathic granulomatous disease affecting multiple organs. Neurosarcoidosis, involving the central and/or peripheral nervous systems, is a relatively rare form of sarcoidosis. Its clinical manifestations include cranial neuropathies, meningitis, neuroendocrinological dysfunction, hydrocephalus, seizures, neuropsychiatric symptoms, myelopathy and neuropathies. The diagnosis is problematic, especially when occurring as an isolated form without other organ involvement. Distinguishing neurosarcoidosis from other granulomatous diseases and multiple sclerosis is especially important. Although biopsy of neural tissue is the gold standard for the diagnosis of neurosarcoidosis, this is often not practical and the diagnosis must be inferred though other tests, often coupled with biopsy of extraneural organs. Corticosteroids and other immuno-suppressants are frequently used for the treatment of neurosarcoidosis. This article reviews the epidemiology, pathogenesis, pathology, clinical features, diagnosis, diagnostic tests, diagnostic criteria, and therapy of neurosarcoidosis.

Neurological deficits during treatment with tumor necrosis factor-alpha antagonists.

INTRODUCTION: Neurological deficits that occur during treatment with tumor necrosis factor (TNF)-α antagonists are rare, and their clinical features have not been fully elucidated. METHODS: Retrospective review of medical records of 9 patients who were given TNF-α antagonists, subsequently developed neurological deficits and were cared for at the Medical University of South Carolina between January 2002 and May 2010. Adverse drug reaction probability scale was used for the assessment of their causal connection. RESULTS: The underlying diseases for which TNF-α antagonists were administered included rheumatologic disorders (4), sarcoidosis (3), psoriasis (1) and Crohn's disease (1). Etanercept, infliximab or adalimumab was administered to these patients. Neurological complications included central or peripheral demyelination (5), antiphospholipid syndrome/central nervous system lupus (1), Epstein-Barr virus encephalitis (1), axonal sensory polyneuropathy (1) and small fiber polyneuropathy (1). TNF-α antagonists were discontinued in 8 patients and clinical improvement was seen in 3 of them. Additional therapies were given in 4 patients. An adverse drug reaction probability score suggested probable (3/9) and possible (6/9) causal relationships. CONCLUSIONS: Neurological deficits that develop during treatment with TNF-α antagonists are relatively rare but important potential complications of these drugs. Determining if the relationship between the neurological deficits and TNF-α antagonist therapy is causal can be challenging and can impact patient care.

Calpeptin attenuated apoptosis and intracellular inflammatory changes in muscle cells.

In idiopathic inflammatory myopathies (IIMs), extracellular inflammatory stimulation is considered to induce secondary intracellular inflammatory changes including expression of major histocompatibility complex class-I (MHC-I) and to produce a self-sustaining loop of inflammation. We hypothesize that activation of calpain, a Ca(2+) -sensitive protease, bridges between these extracellular inflammatory stress and intracellular secondary inflammatory changes in muscle cells. In this study, we demonstrated that treatment of rat L6 myoblast cells with interferon-γ (IFN-γ) caused expression of MHC-I and inflammation-related transcription factors (phosphorylated-extracellular signal-regulated kinase 1/2 and nuclear factor-κB). We also demonstrated that treatment with tumor necrosis factor-α (TNF-α) induced apoptotic changes and activation of calpain and cyclooxygenase-2. Furthermore, we found that posttreatment with calpeptin attenuated the intracellular changes induced by IFN-γ or TNF-α. Our results indicate that calpain inhibition attenuates apoptosis and secondary inflammatory changes induced by extracellular inflammatory stimulation in the muscle cells. These results suggest calpain as a potential therapeutic target for treatment of IIMs.

Calpain inhibition attenuates intracellular changes in muscle cells in response to extracellular inflammatory stimulation.

Idiopathic inflammatory myopathies (IIMs), comprising of polymyositis, dermatomyositis, and inclusion-body myositis, are characterized by muscle weakness and various types of inflammatory changes in muscle cells. They also show non-inflammatory changes, including perifascicular atrophy, mitochondrial changes, and amyloid protein accumulation. It is possible that some molecules/mechanisms bridge the extracellular inflammatory stimulation and intracellular non-inflammatory changes. One such mechanism, Ca(2+) influx leading to calpain activation has been proposed. In this study, we demonstrated that post-treatment with calpeptin (calpain inhibitor) attenuated intracellular changes to prevent apoptosis (Wright staining) through both mitochondrial pathway (increase in Bax:Bcl-2 ratio) and endoplasmic reticulum stress pathway (activation of caspase-12), which were induced by interferon-gamma (IFN-γ) stimulation in rat L6 myoblast cells. Our results also showed that calpeptin treatment inhibited the expression of calpain, aspartyl protease cathepsin D, and amyloid precursor protein. Thus, our results indicate that calpain inhibition plays a pivotal role in attenuating muscle cell damage from inflammatory stimulation due to IFN-γ, and this may suggest calpain as a possible therapeutic target in IIMs.

High dose cyclophosphamide treatment in Marburg variant multiple sclerosis A case report.

Marburg variant multiple sclerosis (MS) is an acute, fulminant and monophasic variant of MS that usually leads to death within weeks to months. No consistently successful treatment is known. We describe a 26-year-old woman who developed acute and progressive motor and sensory deficits. Demyelinating disease was suspected based on brain and spinal MRI and cerebrospinal fluid results. Multiple treatments including corticosteroids, plasma exchange and intravenous immunoglobulin could not halt her clinical and radiological deterioration. She became near quadriplegic and developed motor aphasia. A diagnosis of Marburg variant MS was considered and she was given high dose cyclophosphamide (HiCy) at 50mg/kg/day for four consecutive days, followed by granulocyte colony-stimulating factor six days after the completion of the cyclophosphamide treatment. HiCy successfully induced neutropenia. She started to show a steady neurological improvement from day 17 of HiCy treatment. MR studies two months after HiCy treatment showed significant decrease in the size and enhancement of the lesions. Five months later she had minimal residual right-sided weakness and was able to ambulate without assistance. The great outcome seen in our case suggests that HiCy should be considered as a potential treatment for patients with Marburg variant MS who fail to respond to standard therapy.

A randomized study of alglucosidase alfa in late-onset Pompe's disease.

BACKGROUND: Pompe's disease is a metabolic myopathy caused by a deficiency of acid alpha glucosidase (GAA), an enzyme that degrades lysosomal glycogen. Late-onset Pompe's disease is characterized by progressive muscle weakness and loss of respiratory function, leading to early death. We conducted a randomized, placebo-controlled trial of alglucosidase alfa, a recombinant human GAA, for the treatment of late-onset Pompe's disease. METHODS: Ninety patients who were 8 years of age or older, ambulatory, and free of invasive ventilation were randomly assigned to receive biweekly intravenous alglucosidase alfa (20 mg per kilogram of body weight) or placebo for 78 weeks at eight centers in the United States and Europe. The two primary end points were distance walked during a 6-minute walk test and percentage of predicted forced vital capacity (FVC). RESULTS: At 78 weeks, the estimated mean changes from baseline in the primary end points favored alglucosidase alfa (an increase of 28.1+/-13.1 m on the 6-minute walk test and an absolute increase of 3.4+/-1.2 percentage points in FVC; P=0.03 and P=0.006, respectively). Similar proportions of patients in the two groups had adverse events, serious adverse events, and infusion-associated reactions; events that occurred only in patients who received the active study drug included anaphylactic reactions and infusion-associated reactions of urticaria, flushing, hyperhidrosis, chest discomfort, vomiting, and increased blood pressure (each of which occurred in 5 to 8% of the patients). CONCLUSIONS: In this study population, treatment with alglucosidase alfa was associated with improved walking distance and stabilization of pulmonary function over an 18-month period. (ClinicalTrials.gov number, NCT00158600.)

Polyglutamine represses cAMP-responsive-element-mediated transcription without aggregate formation.

Transcriptional dysregulation, particularly cAMP-responsive-element-mediated transcriptional repression, has been implicated in expanded polyglutamine diseases. However, it has not been clarified whether this transcriptional repression is a cause or result of neurodegeneration. Furthermore, the association between aggregates of expanded polyglutamine stretches and transcriptional repression is not clear. We established isogenic cell lines with polyglutamine stretches, which also expressed d2EGFP under the control of cAMP-responsive elements. In this system, the polyglutamine stretch repressed cAMP-responsive-element-mediated transcription without the formation of macroscopic expanded polyglutamine aggregates. Furthermore, aggregate formation did not have an adverse effect on the repression of transcriptional activity. The results demonstrated that the repression of cAMP-responsive-element-mediated transcription is an early event caused by a soluble form of polyglutamine stretch.