Atypical and delayed spinal cord MRI features of COVID-19-associated myelopathies: a report of four cases and literature review

We reported four patients with coronavirus disease 2019 (COVID-19)-associated myelopathies, highlighting the delayed and atypical spinal cord magnetic resonance imaging (MRI) features and the literature review. All four patients were males, aged 37 to 72 years old. The latencies from COVID-19 to the onset of myelitis were 5, 15, 30, and 80 days. The initial symptoms were numbness and weakness of lower limbs in three cases, and back pain with weakness of lower limbs in one case. The peak symptoms included paraplegia, sphincter dysfunction, sensory disturbance level, and spastic gait. The EDSS scores were 7.5, 9.0, 9.0, and 7.5, respectively. Magnetic resonance imaging (MRI) showed delayed atypical spinal cord lesions at onset, i.e., two cases without lesions, one with linear spinal meningeal enhancement, and one with punctate lesions on T2-weighted imaging (T2WI). During the follow-up period, punctate, linear, and cloudy lesions in the lateral and posterior funiculus were seen on T2WI in the peak stage. The prominent features of spinal cord lesions were linear spinal meningeal enhancement, the mismatch of deteriorated clinical symptoms, and inapparent MRI findings. All four patients were left with an obvious disability, with two patients completely bedridden and two who could stand with support. This report highlights the recognition of COVID-19-associated myelopathy even months after initial infection, especially in patients with delayed and atypical spinal cord findings on MRI.

Effect of CHRFAM7A Δ2bp gene variant on secondary inflammation after spinal cord injury

The α7 neuronal nicotinic acetylcholine receptors (α7nAChRs) are essential for anti-inflammatory responses. The human-specific CHRFAM7A gene and its 2bp deletion polymorphism (Δ2bp variant) encodes a structurally-deficient α7nAChRs that may impact the anti-inflammatory function. We studied 45 spinal cord injury (SCI) patients for up to six weeks post SCI to investigate the role of the Δ2bp variant on multiple circulating inflammatory mediators and two outcome measures (neuropathic pain and risk of pressure ulcers). The patient's SCI were classified as either severe or mild. Missing values were imputed. Overall genetic effect was conducted with independent sample t-test and corrected with false discovery rate (FDR). Univariate analysis and regression analysis were applied to evaluate the Δ2bp effects on temporal variation of inflammatory mediators post SCI and their interaction with outcome measures. In severe SCI, the Δ2bp carriers showed higher levels of circulating inflammatory mediators than the Δ2bp non-carriers in TNF-α (FDR = 9.6x10-4), IFN-γ (FDR = 1.3x10-3), IL-13 (FDR = 1.6x10-3), CCL11 (FDR = 2.1x10-3), IL-12p70 (FDR = 2.2x10-3), IL-8 (FDR = 2.2x10-3), CXCL10 (FDR = 3.1x10-3), CCL4 (FDR = 5.7x10-3), IL-12p40 (FDR = 7.1x10-3), IL-1b (FDR = 0.014), IL-15 (FDR = 0.024), and IL-2 (FDR = 0.037). IL-8 and CCL2 were negatively associated with days post injury (DPI) for the Δ2bp carriers (P = 2x10-7 and P = 2x10-8, respectively) and IL-5 was positively associated with DPI for the Δ2bp non-carriers (P = 0.015). Neuropathic pain was marginally positively associated with IL-13 for the Δ2bp carriers (P = 0.056). In mild SCI, the Δ2bp carriers had lower circulating levels of IL-15 (FDR = 0.04) than the Δ2bp non-carriers. Temporal variation of inflammatory mediators post SCI was not associated with the Δ2bp variant. For the mild SCI Δ2bp carriers, risk of pressure ulcers was positively associated with circulating levels of IFN-γ, CXCL10, and CCL4 and negatively associated with circulating levels of IL-12p70. These findings support an important role for the human-specific CHRFAM7A Δ2bp gene variant in modifying anti-inflammatory function of α7nAChRs following SCI.

Neuregulin-1 beta 1 is implicated in pathogenesis of multiple sclerosis

Multiple sclerosis is characterized by immune mediated neurodegeneration that results in progressive, life-long neurological and cognitive impairments. Yet, the endogenous mechanisms underlying multiple sclerosis pathophysiology are not fully understood. Here, we provide compelling evidence that associates dysregulation of neuregulin-1 beta 1 (Nrg-1β1) with multiple sclerosis pathogenesis and progression. In the experimental autoimmune encephalomyelitis model of multiple sclerosis, we demonstrate that Nrg-1β1 levels are abated within spinal cord lesions and peripherally in the plasma and spleen during presymptomatic, onset and progressive course of the disease. We demonstrate that plasma levels of Nrg-1β1 are also significantly reduced in individuals with early multiple sclerosis and is positively associated with progression to relapsing-remitting multiple sclerosis. The functional impact of Nrg-1β1 downregulation preceded disease onset and progression, and its systemic restoration was sufficient to delay experimental autoimmune encephalomyelitis symptoms and alleviate disease burden. Intriguingly, Nrg-1β1 therapy exhibited a desirable and extended therapeutic time window of efficacy when administered prophylactically, symptomatically, acutely or chronically. Using in vivo and in vitro assessments, we identified that Nrg-1β1 treatment mediates its beneficial effects in EAE by providing a more balanced immune response. Mechanistically, Nrg-1β1 moderated monocyte infiltration at the blood-CNS interface by attenuating chondroitin sulphate proteoglycans and MMP9. Moreover, Nrg-1β1 fostered a regulatory and reparative phenotype in macrophages, T helper type 1 (Th1) cells and microglia in the spinal cord lesions of EAE mice. Taken together, our new findings in multiple sclerosis and experimental autoimmune encephalomyelitis have uncovered a novel regulatory role for Nrg-1β1 early in the disease course and suggest its potential as a specific therapeutic target to ameliorate disease progression and severity.

Acute and non-resolving inflammation associate with oxidative injury after human spinal cord injury

Traumatic spinal cord injury is a devastating insult followed by progressive cord atrophy and neurodegeneration. Dysregulated or non-resolving inflammatory processes can disturb neuronal homeostasis and drive neurodegeneration. Here, we provide an in-depth characterization of innate and adaptive inflammatory responses as well as oxidative tissue injury in human traumatic spinal cord injury lesions compared to non-traumatic control cords. In the lesion core, microglia were rapidly lost while intermediate (co-expressing pro- as well as anti-inflammatory molecules) blood-borne macrophages dominated. In contrast, in the surrounding rim, TMEM119+ microglia numbers were maintained through local proliferation and demonstrated a predominantly pro-inflammatory phenotype. Lymphocyte numbers were low and mainly consisted of CD8+ T cells. Only in a subpopulation of patients, CD138+/IgG+ plasma cells were detected, which could serve as candidate cellular sources for a developing humoral immunity. Oxidative neuronal cell body and axonal injury was visualized by intracellular accumulation of amyloid precursor protein (APP) and oxidized phospholipids (e06) and occurred early within the lesion core and declined over time. In contrast, within the surrounding rim, pronounced APP+/e06+ axon-dendritic injury of neurons was detected, which remained significantly elevated up to months/years, thus providing mechanistic evidence for ongoing neuronal damage long after initial trauma. Dynamic and sustained neurotoxicity after human spinal cord injury might be a substantial contributor to (i) an impaired response to rehabilitation; (ii) overall failure of recovery; or (iii) late loss of recovered function (neuro-worsening/degeneration).

Acute Flaccid Myelitis With Neuroradiological Finding of Brachial Plexus Swelling

BACKGROUND

Acute flaccid myelitis is a recently defined clinically distinct syndrome of polio-like acute flaccid paralysis. Acute flaccid myelitis cases show characteristic neuroradiological features of longitudinal spinal cord lesions with predominant gray matter involvement. Current evidence suggests injury to the anterior horn neurons as the underlying mechanism.

METHODS

We describe three patients with acute flaccid myelitis who developed flaccid upper limb weakness with diminished deep tendon reflexes after prodromal fever. Spinal magnetic resonance imaging (MRI) (axial and sagittal T1- and T2-weighted sequences) and brachial plexus MRI (coronal short tau inversion recovery sequence) at the acute stage were performed.

RESULTS

Spinal MRI showed extensive longitudinal lesion in the spinal cord with predominant gray matter involvement. We were able to demonstrate concurrent swelling and hyperintensity in the brachial plexus in all the three patients at the acute stage.

CONCLUSION

The coexisting signal intensities suggest an extension of acute flaccid myelitis pathology to the brachial plexus, highlighting the possible peripheral nerve involvement in acute flaccid myelitis.

Clinical and MRI phenotypes of sarcoidosis-associated myelopathy

OBJECTIVE

To determine the characteristic clinical and spinal MRI phenotypes of sarcoidosis-associated myelopathy (SAM), we analyzed a large cohort of patients with this disorder.

METHODS

Patients diagnosed with SAM at a single center between 2000 and 2018 who met the established criteria for definite and probable neurosarcoidosis were included in a retrospective analysis to identify clinical profiles, CSF characteristics, and MRI lesion morphology.

RESULTS

Of 62 included patients, 33 (53%) were male, and 30 (48%) were African American. SAM was the first clinical presentation of sarcoidosis in 49 patients (79%). Temporal profile of symptom evolution was chronic in 81%, with sensory symptoms most frequently reported (87%). CSF studies showed pleocytosis in 79% and CSF-restricted oligoclonal bands in 23% of samples tested. Four discrete patterns of lesion morphology were identified on spine MRI: longitudinally extensive myelitis (n = 28, 45%), short tumefactive myelitis (n = 14, 23%), spinal meningitis/meningoradiculitis (n = 14, 23%), and anterior myelitis associated with areas of disc degeneration (n = 6, 10%). Postgadolinium enhancement was seen in all but 1 patient during the acute phase. The most frequent enhancement pattern was dorsal subpial enhancement (n = 40), followed by meningeal/radicular enhancement (n = 23) and ventral subpial enhancement (n = 12). In 26 cases (42%), enhancement occurred at locations with coexisting structural changes (e.g., spondylosis).

CONCLUSIONS

Recognition of the clinical features (chronically evolving myelopathy) and distinct MRI phenotypes (with enhancement in a subpial and/or meningeal pattern) seen in SAM can aid diagnosis of this disorder. Enhancement patterns suggest that SAM may have a predilection for areas of the spinal cord susceptible to mechanical stress.

Clinical and Histopathological Amelioration of Experimental Autoimmune Encephalomyelitis by AAV Vectors Expressing a Soluble Interleukin-23 Receptor

The role of the T helper (Th)17 pathway has been clearly demonstrated in the onset and progression of autoimmune diseases, where interleukin (IL)-23 is a key molecule in maintaining the response mediated by Th17 cells. As a consequence, recent strategies based on blocking the interaction between IL-23 and its receptor (IL-23R), for example the anti-p19 antibody tildrakizumab, have been developed to regulate the Th17 pathway from the initial stages of the disease. Here, a soluble (s)IL-23R cDNA was cloned in expression plasmids and viral vectors. The clinical efficacy of sIL-23R was evaluated in myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis mice intravenously injected with a single dose of adeno-associated virus AAV8-sIL-23R vectors. Cytokine secretion was determined by multiplex assay, while histopathological analysis of the central nervous system was performed to study demyelination, inflammatory infiltration, and microglia and astroglia activation. We observed that administration of adeno-associated vector 8 encoding sIL-23R was associated with a significant disease improvement, including delay in the onset of the clinical signs; slower progress of the disease; interference with IL-23-mediated signal transducer and activator of transcription response by inhibiting of signal transducer and activator of transcription 3 phosphorylation; reduced demyelination and infiltration in the central nervous system; and lower astrocyte and microglia activation. Our results suggest that the use of vectors carrying sIL-23R to block the IL-23/IL-23R interaction may be a new therapeutic strategy for the treatment of multiple sclerosis.

A mouse model of paralytic myelitis caused by enterovirus D68

In 2014, the United States experienced an epidemic of acute flaccid myelitis (AFM) cases in children coincident with a nationwide outbreak of enterovirus D68 (EV-D68) respiratory disease. Up to half of the 2014 AFM patients had EV-D68 RNA detected by RT-PCR in their respiratory secretions, although EV-D68 was only detected in cerebrospinal fluid (CSF) from one 2014 AFM patient. Given previously described molecular and epidemiologic associations between EV-D68 and AFM, we sought to develop an animal model by screening seven EV-D68 strains for the ability to induce neurological disease in neonatal mice. We found that four EV-D68 strains from the 2014 outbreak (out of five tested) produced a paralytic disease in mice resembling human AFM. The remaining 2014 strain, as well as 1962 prototype EV-D68 strains Fermon and Rhyne, did not produce, or rarely produced, paralysis in mice. In-depth examination of the paralysis caused by a representative 2014 strain, MO/14-18947, revealed infectious virus, virion particles, and viral genome in the spinal cords of paralyzed mice. Paralysis was elicited in mice following intramuscular, intracerebral, intraperitoneal, and intranasal infection, in descending frequency, and was associated with infection and loss of motor neurons in the anterior horns of spinal cord segments corresponding to paralyzed limbs. Virus isolated from spinal cords of infected mice transmitted disease when injected into naïve mice, fulfilling Koch’s postulates in this model. Finally, we found that EV-D68 immune sera, but not normal mouse sera, protected mice from development of paralysis and death when administered prior to viral challenge. These studies establish an experimental model to study EV-D68-induced myelitis and to better understand disease pathogenesis and develop potential therapies.

Reports of polio-like paralysis, referred to as acute flaccid myelitis (AFM), have recently emerged in association with infections caused by enterovirus D68 (EV-D68). In the second half of 2014, 120 cases of AFM, mostly in young children, were reported during a nationwide outbreak of EV-D68 respiratory disease. The number of AFM cases has risen again in 2016. Although epidemiological evidence between EV-D68 infection and AFM is accumulating, a causal link has not been definitely established. Here we demonstrate that strains of EV-D68 recovered during the 2014 epidemic can cause a paralytic illness in mice that resembles human AFM. Evidence that EV-D68 causes paralysis in this mouse model include: (1) loss of spinal cord motor neurons innervating paralyzed limbs, (2) detection of virus in the spinal cord and, specifically, motor neurons, (3) transmission of neurological disease when injecting virus isolated from spinal cords of paralyzed mice into naïve mice, thus fulfilling Koch’s postulates, and (4) the ability to prevent AFM by pre-administering serum containing EV-D68 antibodies from previously infected mice. This experimental mouse model can be used to better understand the pathogenesis of EV-D68-induced CNS disease and to facilitate the development of potential therapies.

The role of exosomes in CNS inflammation and their involvement in multiple sclerosis

Multiple sclerosis (MS) is a putative autoimmune disease of the central nervous system (CNS) in which autoreactive immune cells recognizing myelin antigens lead to demyelination and axonal injury. Mechanisms relevant to the pathogenesis of MS have not been fully elucidated, particularly those underlying initiation of immune system dysfunction. For example, it is not known how reactivity against CNS components is generated within the peripheral immune system. In this review, we propose that a significant contribution to the immunoregulatory events may derive from a cell-to-cell communication system involving the production, secretion and transfer of extracellular vesicles known as exosomes. Herein, we discuss in detail the biogenesis and roles of these cell surface-generated vesicles from the standpoint of receptors and their cargo, microRNA. It is well known that exosomes can cross the blood-brain barrier and thus may contribute to the spread of brain antigens to the periphery. Further understanding of exosome-dependent mechanisms in MS should provide a novel angle to the analysis of the pathogenesis of this disease. Finally, we launch the idea that exosomes and their contents may serve as biomarkers in MS.

Spinal diffusion tensor tractography for differentiation of intramedullary tumor-suspected lesions

BACKGROUND AND PURPOSE

Primary MRI diagnosis of spinal intramedullary tumor-suspected lesions can be challenging and often requires spinal biopsy or resection with a substantial risk of neurological deficits. We evaluated whether Diffusion Tensor Imaging (DTI) tractography can facilitate the differential diagnosis.

MATERIALS AND METHODS

Twenty-five consecutive patients with an intramedullary tumor-suspected lesion considered for spinal surgery were studied with a Diffusion-weighted multi-shot read out segmented EPI sequence (RESOLVE). White matter tracts ("streamlines") were calculated using the FACT algorithm and visually co-registered to a T2-weighted 3D sequence. The fused images were assessed concerning spinal streamline appearance as normal, displaced or terminated. Definite diagnosis was verified by histological analysis or further clinical work-up.

RESULTS

All patients with normal appearing streamlines (n=6) showed an acute inflammatory demyelinating pathology in the further clinical work-up. In 10 patients streamline displacing lesions were found from which 5 patients underwent a surgical treatment with histologically confirmed low-grade tumors like ependymomas and pilocytic astrocytomas. In nine patients streamlines were terminated, from which 6 patients received a histology proven diagnoses with a more heterogenous spectrum (3 cases of high grade tumor, 1 case of low grade tumor with intralesional hemorrhage and 2 cases with gliosis but no tumor cells).

CONCLUSION

Using multi-shot DTI spinal tractography acute inflammatory lesions can be differentiated from other tumorous intramedullary lesions. The entity diagnosis of spinal tumors seems to be more challenging, primarily due to the variety of factors like invasivity, expansion or intralesional hemorrhage.

Marked inflammation in catastrophic longitudinal myelitis associated with systemic lupus erythematosus

Catastrophic longitudinal myelitis is an extremely rare neurologic manifestation of collagen vascular disease, described heretofore in 11 cases of SLE and 1 of Sjogren's Syndrome. This report documents markedly abnormal and worsening CSF findings on sequential CSF examinations over a period of three days (WBC >1500 cells/μL, >80% neutrophils, markedly elevated protein, and extremely low glucose levels) in the absence of infection. These abnormalities cleared rapidly with institution of immunosuppressive therapy so that a third CSF exam done within three days revealed almost complete normalization of CSF values. These findings suggest that in some cases of CLM a strong inflammatory component may be present, while in others, other pathogenic factors may predominate. Lupus (2007) 16, 823—826.

Autologous blood stem cell transplantation in refractory systemic lupus erythematodes with recurrent longitudinal myelitis and cerebral infarction

Autologous hematopoietic stem cell transplantation (ASCT) has the potential to eliminate autoreactive lymphocytes and may represent a therapeutic option for patients with refractory autoimmune diseases. We describe a 19-year old woman with neuropsychiatric systemic lupus erythematodes (NPSLE) presenting with acute longitudinal myelitis and aseptic meningitis. Despite therapy with methylprednisolone and cyclophosphamide (CYC), recurrence of longitudinal myelitis and a disabling stroke-like relapse occurred. Hematopoietic stem cells were mobilized by CYC at 2 g/m2 and G-CSF. The patient was conditioned by CYC at 200 mg/kg and anti-thymocyte globulin and 3.6 = 106 CD34+ cells/kg were infused. Hematopoietic regeneration was observed on day 12 after ASCT. Currently, 18 months after ASCT, the patient is in clinical remission with no evidence for residual serological or neuroradiological activity of SLE. Although a longer follow-up will be needed to reliably assess the efficacy of ASCT in this patient, the present case demonstrates that ASCT may represent a therapeutic option for patients with severe NPSLE.

A case of tumor-like inflammatory demyelinating disease with progressive brain and spinal cord involvement

CONTEXT

Tumor-like inflammatory demyelinating disease (TIDD) usually occurs in the brain and rarely occurs in the spinal cord. TIDD appears to be very similar to tumors such as gliomas on imaging, which may lead to incorrect or delayed diagnosis and treatment.

CASE REPORT

Because of headache and incoherent speech, a 24-year-old Chinese male presented to our hospital with a two-week history of respiratory infections. After dexamethasone treatment, his symptoms still got worse and surgery was performed for diagnostic purposes. Histological examination revealed that the lesion was inflammatory. Further lesions appeared in the spine (T3 and T4 levels) after two months and in the right occipital lobe after three months. After intravenous immunoglobulin (IVIG) and methylprednisolone treatment, his symptoms improved.

CONCLUSION

Progressive lesions may damage the brain and spinal cord, and long-term prednisolone and IVIG therapy are beneficial in TIDD patients.

Angelica Sinensis attenuates inflammatory reaction in experimental rat models having spinal cord injury

This study was aimed to evaluate the effect of Angelica Sinensis on experimental rat models in which spinal cord injury was induced by studying different factors. Different factors causing inflammation play a key role in pathophysiology of SCI. Here three groups of rats (n=15, each was used). These included a sham control group where only laminectomy was performed, SCI group where SCI was induced and AS/SCI group where although SCI was induced but Angelica Sinensis was also administered to study its effect and draw a comparison with control. The expression of I-kBα and NF-kB p65 was also studied using western blotting and after recording optical density (OD) values of western blots. MPO activity was used to measure the effect of 20 mg/kg Angelica Sinensis. The levels of proinflammatory cytokines TNF-α, IL-1β and IL-6 were also studied. As compared with SCI group and sham control it was observed that Angelica Sinensis significantly reduced the expression of I-kBα and NF-kB p65, (P<0.05), while MPO activity was also significantly reduced. Proinflammatory cytokine level was also reduced in treated group as compared to both other groups. On the basis of this study we concluded that the use of 20 mg/kg Angelica Sinensis in rat models can attenuate the secondary damage caused by SCI and thus help in controlling the pathology of SCI in rats.

Viral diseases of the central nervous system

Virus-induced diseases of the central nervous system (CNS) represent a significant burden to human health worldwide. The complexity of these diseases is influenced by the sheer number of different neurotropic viruses, the diverse routes of CNS entry, viral tropism, and the immune system. Using a combination of human pathological data and experimental animal models, we have begun to uncover many of the mechanisms that viruses use to enter the CNS and cause disease. This review highlights a selection of neurotropic viruses that infect the CNS and explores the means by which they induce neurological diseases such as meningitis, encephalitis, and myelitis.

Central nervous system tuberculosis

Tuberculosis (TB) has shown a resurgence in nonendemic populations in recent years and accounts for 8 million deaths annually in the world. Central nervous system involvement is one of the most serious forms of this infection, acting as a prominent cause of morbidity and mortality in developing countries. The rising number of cases in developed countries is mostly attributed to factors such as the pandemic of acquired immunodeficiency syndrome and increased migration in a globalized world. Mycobacterium TB is responsible for almost all cases of tubercular infection in the central nervous system. It can manifest in a variety of forms as tuberculous meningitis, tuberculoma, and tubercular abscess. Spinal infection may result in spondylitis, arachnoiditis, and/or focal intramedullary tuberculomas. Timely diagnosis of central nervous system TB is paramount for the early institution of appropriate therapy, because delayed treatment is associated with severe morbidity and mortality. It is therefore important that physicians and radiologists understand the characteristic patterns, distribution, and imaging manifestations of TB in the central nervous system. Magnetic resonance imaging is considered the imaging modality of choice for the study of patients with suspected TB. Advanced imaging techniques including magnetic resonance perfusion and diffusion tensor imaging may be of value in the objective assessment of therapy and to guide the physician in the modulation of therapy in these patients.

Magnetic resonance imaging in neurocysticercosis

Cysticercosis in one of the most common parasitic infections in the central nervous system. The complex and unpredictable nature of the host immune reaction against cysticercosis as well as the pleomorphism of your injuries make the disease neurocysticercosis interesting and fascinating to study. Imaging studies play an important role in the diagnosis of this disease. Advanced imaging techniques have improved detection and visualization of scolex cysts extraparenchymal spaces.

Regulation of autophagy via PERK-eIF2α effectively relieve the radiation myelitis induced by iodine-125

Radiation myelitis is the most serious complication in clinical radiotherapy for spinal metastases. We previously showed that ¹²⁵I brachytherapy induced apoptosis of spinal cord neurons accompanied by autophagy. In this study, we further investigated the mechanism by which ¹²⁵I radiation triggered autophagy in neural cells. We found that autophagy induced by ¹²⁵I radiation was involved in endoplasmic reticulum (ER) stress and mainly dependent on PERK-eIF2α pathway. The expressions of LC3II, ATG12 and PI3K were significantly suppressed in PERK knockout neural cells. Meanwhile, the expressions of phosphorylated-Akt s473 and caspase3/8 all significantly increased in neural cells transfected with a PERK siRNA and which enhanced apoptosis of neurons after ¹²⁵I radiation. The results were consistent with that by MTT and Annexin-FITC/PT staining. In annimal model of banna pigs with radiation myelitis caused by ¹²⁵I brachytherapy, we have successfully decreased PERK expression by intrathecal administration of the lentivirus vector. The apoptosis rate was significantly higher than that in control group and which deteriorated radiation myelitis of banna pigs. Thus, autophagy caused by ¹²⁵I radiation was mainly as an attempt of cell survival at an early stage, but it would be a self-destructive process and promoted the process of apoptosis and necrosis radiated by ¹²⁵I for more than 72 hours. The study would be useful and helpful to maximize efficiency of radiation therapy in clinical therapy.

An analysis of cervical non-infectious inflammatory myelitis risk factors

BACKGROUND

Non-infectious inflammatory myelitis or non-infectious myelitis (NIM) is an inflammatory condition that occurs following an immune response in the central nervous system (CNS). In cases of spinal disc degeneration, multiple factors converge to cause pathologic changes in disc structure. To date, no studies have examined the potential relationship between disc degeneration and NIM.

OBJECTIVES

To investigate the relationship between cervical NIM and cervical disc degeneration.

METHODS

Magnetic resonance imaging (MRI) was used to examine 85 patients with cervical NIM. Peripheral levels of the pro-inflammatory cytokines, interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-alpha) were also measured. Non-infectious myelitis occurrence rates and TNF-alpha and IL-6 levels were compared between patients with cervical disc degeneration and a control group. The relationship between cervical NIM and cervical disc degeneration was analyzed with logistic regression and a receiver operating characteristic (ROC) curve.

RESULTS

Magnetic resonance imaging showed that 78.8% of patients with myelitis exhibited disc degeneration compared to only 18.9% of the control group. Moreover, IL-6 and TNF-alpha levels in patients with NIM were significantly higher than those in the control group; levels of these inflammatory cytokines were even higher in NIM patients with cervical disc degeneration than in those without.

CONCLUSIONS

Our results suggest that patients with cervical NIM have a higher incidence of cervical disc degeneration, indicating that cervical disc degeneration is likely a possible risk factor in cervical NIM progression. Future quantitative studies are required to confirm this observation.

Systemic lupus erythematosus presented as extensive longitudinal myelitis

BACKGROUND

longitudinal myelitis (LM) is defined by the continuous lesion of more than four spinal cord segments. LM is a rare variant of acute transverse myelitis and it frequently presented poor responses to immunomodulatory therapy, which resulted in severe and disabling sequelae. We reported a case of acute longitudinal myelitis involving extensive lesions from cervical spinal cord to conus medullaris caused by newly diagnosed SLE.

CASE REPORT

A 39 years old man who was previously healthy presented to our hospital due to acute urinary retention with progressive lower limb weakness for a week. Brisk deep tendon reflexes in upper limbs and decreased reflexes in lower limbs were noted on admission. The pin-prick, vibration, and light touch sensations were decreased in the lower limbs. Spinal MRI sagittal view showed an T2WI bright up mass in the spinal cord below C3/4 level with extension to conus medullaris. He was diagnosed SLE based on ARA criteria. After ruling out mimics including NMO and MS, SLE with LM explained what happened to him .

CONCLUSION

Given the poor prognosis of SLE with LM, which resulted in severe and disabling sequelae. More comprehensive understand of the disease course, real mechanisms and treatment strategy are needed.

An unusual case of spinal cord restricted mycobacteriosis in a European mink

Granulomatous myelitis due to infection with Mycobacterium avium was diagnosed in a 4-year-old male neutered European mink (Mustela lutreola). The causative agent was detected by an acid-fast stain and further characterized by polymerase chain reaction and DNA sequencing of the PCR product. A thorough histological evaluation of the remaining organs revealed no granulomatous lesions or detectable acid-fast organisms. Although minks are generally highly susceptible for mycobacteria, localised infections, especially of the central nervous system, are unusual and may represent an atypical chronic form of the disease.

Huperzine A ameliorates experimental autoimmune encephalomyelitis via the suppression of T cell-mediated neuronal inflammation in mice

Huperzine A (HupA), a sesquiterpene alkaloid and a potent and reversible inhibitor of acetylcholinesterase, possesses potential anti-inflammatory properties and is used for the treatment of certain neurodegenerative diseases such as Alzheimer's disease. However, it is still unknown whether this chemical is beneficial in the treatment of multiple sclerosis, a progressive inflammatory disease of the central nervous system. In this study, we examined the immunomodulatory properties of HupA in experimental autoimmune encephalomyelitis (EAE), a T-cell mediated murine model of multiple sclerosis. The following results were obtained: (1) intraperitoneal injections of HupA significantly attenuate the neurological severity of EAE in mice. (2) HupA decreases the accumulation of inflammatory cells, autoimmune-related demyelination and axonal injury in the spinal cords of EAE mice. (3) HupA down-regulates mRNA levels of the pro-inflammatory cytokines (IFN-γ and IL-17) and chemokines (MCP-1, RANTES, and TWEAK) while enhancing levels of anti-inflammatory cytokines (IL-4 and IL-10) in the spinal cords of EAE mice. (4) HupA inhibits MOG(35-55) stimulation-induced T-cell proliferation and IFN-γ and IL-17 secretion in cultured splenocytes. (5) HupA inhibition of T-cell proliferation is reversed by the nicotinic acetylcholinergic receptor antagonist mecamylamine. We conclude that HupA can ameliorate EAE by suppressing autoimmune responses, inflammatory reactions, subsequent demyelination and axonal injury in the spinal cord. Therefore, HupA may have a potential therapeutic value for the treatment of multiple sclerosis and as a neuroimmunomodulatory drug to control human CNS pathology.

Symptomatic noncompressive motoromyelopathy presents as early manifestation in ankylosing spondylitis

Ankylosing spondylitis (AS) is an autoimmune spondyloarthropathy involving principally the sacroiliac joint and axial skeleton. Spinal cord involvement is an infrequent and late complication. It mostly results from compressive myelopathy due to skeletal osteopathy and usually presents with radiculomyelopathic sensory and motor deficits. To report three patients who suffered a progressive paraparesis/tetraparesis compatible with motor myelopathy without typical skeletal symptom. Myelopathy of unknown origin was initially interpreted in these patients. Radiography did not show typical change at sacroiliac joint or vertebrate. Spinal magnetic resonance image revealed cord atrophy at cervical and thoracic segment. A positivity of B27 antigen was found afterward. Their spondyloarthropathic symptoms developed within six months later with radiographic sacroiliitis. Seropositive AS with noncompressive myelopathy was finally established. Patients showed a reverse of motor impairment when their pain was well undercontrolled. Motor myelopathy may be neglected or underestimated in AS, in especially when typical skeletal symptom is absent or minimal. It may progress surreptitiously to harm spinal function or superimpose to crippling disability in compressive spinal cord injury. Therefore, a careful evaluation and monitor of spinal cord function is important for AS patient despite spinal deformity is not observed.

Subacute longitudinal myelitis associated with Behcet's disease

In neuro-Behcet's disease (NBD), myelitis is a rare clinical form. We report the case of a woman with NBD presenting with unsteady gait and generalized spasticity. Spinal magnetic resonance imaging (MRI) showed multiple and confluent hyperintensities extending throughout the entire spinal cord on a T2-weighted image with some contrast enhancement. High-dose steroid therapy was so effective that the myelitis was markedly improved, as shown in the follow-up MRI. Longitudinal myelitis involving the entire spinal cord, as seen in our patient, has never been described before. This case suggests that NBD could be one of the important differential diagnoses of longitudinal myelitis.

[Analysis of morphological manifestations of the inflammatory reaction in wistar rat spinal cord in experimental model]

Morphological changes in the spinal cord of rats with different intensity of pathological symptoms were studied at the peak of the experimental encephalomyelitis development. Light-microscopical and immunohistochemical methods were used. Distribution of proliferating cell nuclear antigen (PCNA), astrocyte marker - glial fibrillar acidic protein (GFAP), and microglia and macrophage marker Iba-1, was studied. Heterogeneity in morphological manifestations of the experimental allergic encephalomyelitis was shown. Four typical patterns of morphological manifestations of the disease were demonstrated depending on the preferential involvement of pia mater, vessels, spinal cell nuclei or conductive tracts in the pathological process.

Toxocariasis might be an important cause of atopic myelitis in Korea

Atopic myelitis is defined as myelitis with atopic diasthesis but the cause is still unknown. Toxocariasis is one of the common causes of hyperIgEaemia that may lead to neurologic manifestations. The purpose of this study was to evaluate the sero-prevalence of Toxocara specific IgG Ab among the atopic myelitis patients. We evaluated the medical records of 37 patients with atopic myelitis whose conditions were diagnosed between March 2001 and August 2007. Among them, the 33 sera were analyzed for specific serum IgG Ab to Toxocara excretory-secretory antigens (TES). All of 37 patients had hyperIgEaemia. Specific IgE to D. pteronyssinus and D. farinae was detected in 22 (64.7%) and 34 (100%) patients, respectively, of the 34 patients. Thirty-one of 33 patients (93.9%) were found to be positive by TES IgG enzyme-linked immunosorbent assay (ELISA). Based on the image findings of eosinophilic infiltrations in the lung and liver, 8 patients had positive results. These results inferred that the prevalence of toxocariasis was high in patients with atopic myelitis. Our results suggest that toxocariasis might be an important cause of atopic myelitis and Toxocara ELISA is essential for evaluating the causes of atopic myelitis.

Effects of hyperthermia on the central nervous system: What was learnt from animal studies?

Animal studies show that nervous tissue is sensitive to heat. Although inter-species variations may play a role, the data indicate that the maximum heat dose without obvious complications after localized hyperthermia in regions of the central nervous system (CNS) lies in the range of 40-60 min at 42-42.5 degrees C or 10-30 min at 43 degrees C. Expression of thermotolerance after a 'conditioning' heat dose was clearly observed in the spinal cord of rodents and the thermotolerance ratio's (ratio between heat doses with and without conditioning required to obtain a certain defined effect) were high, approximately 2. The thermotolerant state of CNS is shown to protect also against other types of injury as well: pre-treatment of rats with hyperthermia protected against spinal cord ischemic injury. During the rather long period required for temperature elevation which is inherent to WBH, some degree of thermotolerance may develop. The correlation between thermotolerance and hsp70 induction in CNS is obvious. Heat, at least if applied shortly after X-rays, enhances the response of nervous tissue to radiation. Data on the combined effects of X-ray irradiation and hyperthermia on rodent spinal cord clearly show that the radiation response can be enhanced with a factor of 1.1-1.3. There are no clear experimental data indicating an increase in adverse effects specific to the CNS after localized or whole body hyperthermia as a result of combined treatment with chemotherapy.

Idiopathic inflammatory myopathies

Since the description of the first case of dermatomyositis over a century ago, our understanding of myositis has evolved. Bohan and Peter in 1975 established diagnostic criteria for polymyositis and dermatomyositis. Subsequent investigations by Arahata and Engel delineated differences in the lymphocyte subsets on muscle histopathology distinguishing polymyositis and dermatomyositis. Following that, myositis-specific antibodies have been reported in association with various myositis subtypes and with interstitial lung disease. Polymyositis and dermatomyositis are in general responsive to immunosuppressive therapy. Inclusion body myositis (IBM) became recognized as a distinct entity nearly half a century ago. IBM is clinically and pathologically distinct from the other inflammatory myopathies. The weakness in IBM is characteristic, involving both the proximal and distal muscle groups, such as finger flexion, knee extension and ankle dorsiflexion. Vacuolated fibers, amyloid deposition, and filaments on electron microscopy are pathologic hallmarks of IBM. IBM is refractory to corticosteroids and intravenous gamma globulins. This clinical observation and the pathologic features support the hypothesis that IBM is a muscle-degenerative disease. Most recently, a fourth inflammatory myopathy subtype called necrotizing myopathy was described. Necrotizing myopathy may be related to malignancy, other autoimmune diseases, toxic exposure or can be idiopathic. The key histopathologic findings of this entity are necrotic fibers undergoing phagocytosis. Though patients ultimately respond to immunosuppressive therapy, they tend to be more refractory and therefore often require a more aggressive treatment approach.

Cytoskeletal protein carbonylation and degradation in experimental autoimmune encephalomyelitis

Protein carbonylation, the non-enzymatic addition of aldehydes or ketones to specific amino acid residues, has been implicated in the pathophysiology of multiple sclerosis. In this study, we investigated whether protein carbonyls also accumulate in the spinal cord of Lewis rats with acute experimental autoimmune encephalomyelitis (EAE). Western blots analysis after derivatization with dinitrophenyl hydrazine (oxyblot) showed elevated protein carbonylation at the time of maximal clinical disability. During the same period glutathione levels were substantially reduced, suggesting a causal relationship between these two markers. In contrast, lipid peroxidation products accumulated in EAE spinal cord well before the appearance of neurological symptoms. Carbonyl staining was not restricted to inflammatory lesions but present throughout the spinal cord particularly in neuronal cell bodies and axons. By 2-dimensional-oxyblot, we identified several cytoskeletal proteins, including beta-actin, glial acidic fibrillary protein, and the neurofilament proteins as the major targets of carbonylation. These findings were confirmed by pull-down experiments, which also showed an increase in the number of carbonylated beta-actin molecules and a decrease in that of oxidized neurofilament proteins in EAE. These data suggest the possibility that oxidation targets neurofilament proteins for degradation, which may contribute to axonal pathology observed in multiple sclerosis and EAE.

[Value of magnetic resonance imaging in central nervous system tuberculosis]

Tuberculosis of the central nervous system is a major cause of morbidity and mortality in developing nations where it accounts for 10 to 30% of intracranial space-occupying lesions. It preferentially affects young subjects, predominantly male. MRI and in particular new methods, including magnetization transfer and diffusion-weighted imaging, are useful for positive and differential diagnoses of central nervous system tuberculosis and surveillance during treatment.

Abnormalities of spinal magnetic resonance images implicate clinical variability in human T-cell lymphotropic virus type I-associated myelopathy

This study investigated the role of human T-cell lymphotropic virus type I HTLV-I infection in 11 patients who developed slowly progressive myelopathy with abnormal spinal cord lesions. The authors performed clinical and neuroradiological examinations and calculated the odds that an HTLV-I-infected individual of a specific genotype, age, and provirus load has HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Anti-HTLV-I antibodies were present in both the serum and cerebrospinal fluid in all of the patients. Abnormal magnetic resonance imaging (MRI) lesions were classified as cervical to thoracic type (CT type), cervical type (C type), and thoracic type (T type). In each type, there was swelling of the spinal cords with high-intensity lesions, which were located mainly in bilateral posterior columns, posterior horns, or lateral columns. Virological and immunological analyses revealed that all patients showed a high risk of developing HAM/TSP. These 11 patients may have developed HAM/TSP, as manifested by spinal cord abnormalities shown on MRI. These MRIs implicate clinical variability of HAM/TSP, which may indicate active-early stages of HAM/TSP lesions.

Sclérose en plaques : aspects cliniques, encéphalomyélites aiguës disséminées, neuromyélites optiques et variantes inflammatoires

Multiple sclerosis (MS) has been described for more than a century, but its cause remains unknown. Numerous reports were written concerning borderline forms of the disease. In the present review we present MS related disorders such as neuromyelitis optica and acute demyelinating encephalomyelitis.

Enhanced visualization of axonopathy in EAE using thy1-YFP transgenic mice

It is widely accepted that chronic disabilities in multiple sclerosis (MS) patients are due in part to neuronal damage. The central aim of this study was to characterize axonal disruption in the spinal cord of mice with myelin oligodendrocyte glycoprotein-induced experimental autoimmune encephalomyelitis (MOG-EAE), a model of progressive MS. To accomplish this goal, we induced MOG-EAE in thy1-yellow fluorescent (thy-YFP)-transgenic mice in which all spinal motorneurons express the YFP reporter protein. We demonstrate that a build-up of YFP fluorescence occurs in profiles reminiscent of tortuous fragmented axons and axonal spheroids/globules as seen in various neurodegenerative/neuroinflammatory diseases. Approximately two-thirds of these damaged axons were decorated by the monoclonal antibody SMI 32, which recognizes hypophosphorylated neurofilament-H (hypoP-NF-H), an established marker of CNS axonal pathology. Unexpectedly, one third of damaged axons were hypoP-NF-H negative but could be visualized by their expression of the YFP transgene, whilst the remaining profiles were hypoP-NF-H positive but did not exhibit YFP fluorescence. Thus, using YFP transgenic mice in conjunction with hypoP-NF-H immunoreactivity provides a more comprehensive depiction of axonopathy in the ventral-lateral aspect of lumbosacral spinal cord in MOG-EAE. When YFP fluorescence was used in conjunction with a monoclonal antibody that recognizes CD11b; a marker of subsets of inflammatory cells, we were able to discern evidence of an early inflammatory attack on white matter axons. Finally, we show the accumulation of hyperphosphorylated neurofilament-H (hyperP-NF-H) expression in YFP+, lesioned WM areas and in a subpopulation of neuronal perikarya in the lumbar spinal cords of EAE mice.

Cervical spondylotic myelopathy due to chronic compression: the role of signal intensity changes in magnetic resonance images

OBJECT

Although there is agreement that low-intensity signal changes on T1-weighted magnetic resonance (MR) images are a prognostic factor for poor outcome after surgical treatment of cervical myelopathy due to chronic cord compression, the role of high-intensity signal changes on T2-weighted images is still controversial. The aim of the present study was to determine whether T2-weighted MR imaging can help assess the prognosis of the disease.

METHODS

A prospective case series study was conducted. The population comprised 67 patients who underwent surgery between 1994 and 2004 to treat myelopathy caused by chronic cervical cord compression. The mean follow-up period was 39 months. Preoperative and postoperative functional status was evaluated using a modified Japanese Orthopaedic Association scale, and the recovery rate was calculated using the Hirabayashi method. Magnetic resonance images were acquired 3 months or less before surgery. High-intensity signal changes were evaluated according to the extent of these changes on T2-weighted sequences; low-intensity T1-weighted signal changes were also evaluated. In patients with low-intensity changes on T1-weighted images and in those with high-intensity changes spanning multiple levels on T2-weighted images, the authors documented a poor functional recovery.

CONCLUSIONS

Multisegmental high-intensity change on T2-weighted MR imaging is a more sensitive indicator of outcomes than T1-weighted signal changes because of its higher frequency in patients with advanced myelopathy.

[Syrinx formation secondary to cervical epidural abscess]

We report a patient with syrinx formation secondary to cervical epidural abscess, cervical spondylitis, cervical discitis and meningitis. A 53-year-old woman developed sudden fever, headache and neck pain. On admission, neurological evaluation showed limitation of cervical motion, meningeal irritation, and exaggerated muscle stretch reflexes in all four extremities. Cerebrospinal fluid cell count was 832/mm3 and protein was 771 mg/dl. Bacterial culture of the cerebrospinal fluid showed Staphylococcus aureus. A cervical MRI scan with Gd-enhancement revealed focal high intensity signal in the T2-weighted and FLAIR images, at the anterior meninges of the C3-8 segments, the vertebral bodies of C5-6 and the intervertebral disks of C5-6 segment. Her diagnosis was cervical epidural abscess, cervical spondylitis, cervical discitis and meningitis. Antibiotics and steroids improved her symptoms. Six weeks after the onset of symptoms, a cervical MRI scan showed narrowing and synarthrosis in the intervertebral space between C5 and C6. MRI and myelo CT scans demonstrated a newly-formed syrinx from C3-C 7. This was an interesting case of syrinx formation secondary to cervical epidural abscess.

Acute myelitis in a child: current hypotheses

This report presents the case of a child with atopic dermatitis, who developed progressive muscular weakness and hypotonia of the four limbs. The cervical spinal cord magnetic resonance imaging revealed a C(4) lesion (T(2)-weighted images); the cerebrospinal fluid findings were normal. Treatment with intravenous immunoglobulins and methylprednisolone obtained rapid clinical improvement, and approximately 1 month later the small C(4) lesion disappeared. Various diagnostic hypotheses are discussed: acute myelitis by infective agents, acute disseminated encephalomyelitis, multiphasic disseminated encephalomyelitis, multiple sclerosis, and isolated postinfective myelitis. Another hypothesis relates to atopic myelitis, a form recently described in the Japanese literature, associated with atopic dermatitis, hyperIgEemia, and high levels of specific immunoglobulin E to Dermatophagoides farinae and Dermatophagoides pteronyssinus. This diagnosis is difficult to confirm without biopsy evidence of eosinophilic inflammation.

Viral myelitis: An update

Viral infections of the central nervous system are uncommon but are important in the differential diagnosis of acute myelopathy. Acute viral myelitis can present as acute flaccid paralysis (poliomyelitis) or neurologic dysfunction due to involvement of the white matter. The latter usually affects only part of the transverse expanse of the spinal cord and manifests as asymmetric motor and sensory symptoms. When both halves of the spinal cord are affected, the entity is referred to as acute transverse myelitis and patients exhibit uniformly symmetric weakness, sensory loss, and urinary bladder involvement. Acute flaccid paralysis is due to cytolytic infection of anterior horn cells. When the involvement is mainly white matter, virus-specific and autoimmune host cellular immune responses are believed to contribute to spinal cord damage. Acute flaccid paralysis is caused by polioviruses-1, -2, and -3; coxsackieviruses A and B; enterovirus-71; and flaviviruses, including West Nile virus. Involvement of spinal cord white matter may be associated with infection by many different viruses; however, in most cases a specific viral cause is never determined. Chronic myelitis may be due to either direct infection of the spinal cord by human T-cell lymphotrophic virus-1 (HTLV-1), or a metabolic disturbance due to HIV-1 infection in AIDS patients; no other human virus is known to chronically infect the spinal cord without involvement of the brain. The principal treatment is antiviral drugs immediately upon virus isolation or the identification of a viral sequence by PCR and, when indicated, high doses of methylprednisolone.

Progressive white matter pathology in the spinal cord of transgenic mice expressing mutant (P301L) human tau

Transgenic mice expressing mutant (P301L) tau develop paresis, neurofibrillary tangles and neuronal loss in spinal motor neurons beginning at 4 to 6 months of age. Astrocytes and oligodendrocytes acquire filamentous tau inclusions at later ages. Here we report pathology in the spinal white matter of these animals. Progressive white matter pathology, detected as early as 2 months of age, was most marked in lateral and anterior columns, with sparing of posterior columns until late in the disease. Early changes in Luxol fast blue/periodic acid Schiff (LFB/PAS) and toluidine blue stained sections were vacuolation of myelin followed by accumulation of myelin figures within previous axonal tubes and finally influx of PAS-positive macrophages. Myelin debris and vacuoles were found in macrophages. At the ultrastructural level, myelinated axons showed extensive vacuolation of myelin sheaths formed by splitting of myelin lamellae at the intra-period line, while axons were atrophic and contained densely packed neurofilaments. Other axons were lost completely, resulting in collapse and phagocytosis of myelin sheaths. Also present were spheroids derived from swollen axons with thin myelin sheaths containing neurofilaments, tau filaments and degenerating organelles. Many oligodendrocytes had membrane-bound cytoplasmic bodies composed of tightly stacked lamellae capped by dense material. The vacuolar myelopathy in this model to some extent resembles that reported in acquired immune deficiency syndrome and vitamin B12 deficiency. The progressive axonal pathology is most consistent with a dying-back process caused by abnormal accumulation of tau in upstream neurons, while vacuolar myelinopathy may be a secondary manifestation of neuroinflammation.