Neuroimaging of Tuberculous Myelitis: Analysis of Ten Cases and Review of Literature

We retrospectively reviewed the clinical and neuroimaging features of 10 patients with tuberculous myelitis. The most common presenting symptoms were fever (70%) and paraplegia (60%). Bladder and bowel symptoms were present in 90% patients. On MRI, the involvement of the cervical/thoracic segment of the spinal cord was most commonly seen (90%). The most consistent finding was hyperintense signals on T2-weighted MRI. T1-weighted images showed isointense (n= 5) and hypointense (n= 4) signals in the spinal cord lesions. Post-contrast enhancement was present in 6 patients, epidural enhancement in 4 patients, and cord swelling in 2 patients. We reviewed more than 250 published cases with the diagnosis of tuberculous myelitis and radiculomyelitis with special attention to MRI findings. It is predominantly a disease of the thoracic spinal cord. Most spinal cord lesions appear as hyperintense on T2 and iso- or hypointense on T1-weighted images. MRI findings in patients with spinal cord tuberculosis have both diagnostic and prognostic significance. Cord atrophy or cavitation and the presence of syrinx on MRI may be associated with poor outcome.

Natural cases of visna in sheep with myelitis as the sole lesion in the central nervous system

Of 118 sheep with visna, 12 showed myelitis as the only nervous lesion. They were ovine lentivirus (OvLV)-seropositive and provirus DNA was demonstrated by LTR-PCR in all the samples with lesions. Clinically, all showed hindlimb paralysis and some were completely recumbent. Grossly, a swollen and discoloured area was identified in the white matter in 10 sheep. Microscopical changes consisted of a wedge-shaped area of non-suppurative leucomyelitis with mononuclear perivascular cuffing, demyelination and white matter degeneration. Except for two samples, grey matter was affected adjacent to severe white matter lesions. Three different microscopical patterns of lesion were identified, all having in common the presence of perivascular inflammation: the so-called vascular pattern was characterized by perivascular cuffs with minimal lesions in the adjacent neuroparenchyma; the malacic pattern, which was the commonest type, was characterized by severe white matter destruction and small numbers of macrophages; and the infiltrative pattern was characterized by a severe infiltrate of histiocytes in the parenchyma. Maedi-visna virus antigen was detected immunohistochemically only in areas with lesions, and the degree of immunolabelling was unrelated to the severity of the damage. Diagnosticians should bear in mind that a considerable number of visna cases show only spinal cord lesions. Examination of paraffin wax-embedded samples by LTR-PCR and immunohistochemistry would seem useful in confirming a histopathological diagnosis of visna from spinal cord samples.

Fluoro-Jade B staining following zymosan microinjection into the spinal cord white matter

1. The fluorescein derivate Fluoro-Jade B (FJB), which primarily labels dead or dying neurons, was used to study the acute focal inflammation in the spinal cord white matter. Inflammation was induced by microinjection of the yeast particulate zymosan to evaluate the biological effects of intraspinal macrophages activation without the confounding effects of physical trauma. 2. A single bolus of zymosan (Sigma, 75 nL) was stereotaxically injected at the thoracic level into the lateral white matter of rat spinal cord. A standard Fluoro-Jade B staining protocol was applied to spinal cord sections at 6, 12, 24 h and 2, 4 days postinjection. Neutral Red, NADPH-diaphorase, Iba1-IR, and DAPI staining protocols accomplished examination of the cells participating in the acute inflammatory response. 3. Zymosan caused formation of clearly delineated inflammation lesions localized in the lateral white matter of the spinal cord. Fluoro-Jade B stained cells in the area of inflammation were not observed at 12 h postinjection while mild FJB staining appeared at 24 h and intense staining was observed at 2 and 4 days postinjection. 4. This study shows that the acute response to zymosan-induced inflammation in the rat spinal cord white matter causes a gradual appearance of phagocytic microglia/macrophages and delayed FJB staining of the inflammatory cells. 5. FJB, a reliable marker of dying neurons, is a more universal agent than formerly believed. One possible explanation for the gradual appearance of FJB-stained cells in the area of inflammation is that specific time is required for sufficient levels of proteins and/or myelin debris of axonal origin to appear in the cytoplasm of phagocytic microglia/macrophages.

Evolution of Spinal Cord Injury in a Porcine Model of Prolonged Aortic Occlusion

BACKGROUND

Spinal cord injury and subsequent paraplegia remains an unpredictable and devastating complication of thoracoabdominal aortic surgery. The aim of this study was to investigate spinal cord injury due to prolonged thoracoabdominal aortic occlusion.

MATERIALS AND METHODS

We used a highly reproducible porcine model of 45-min thoracoabdominal aortic occlusion, which was accomplished by two balloon occlusion catheters. Neurological evaluation after the end of experiment was performed by an independent observer according to the Tarlov scale. The lower thoracic and lumbar spinal cords were harvested at 10, 48, and 120 h (n = 6 animals per time point) and examined histologically with hematoxylin and eosin (H&E) stain and TUNEL method. Tarlov scores, number of neurons, and the grade of inflammation were analyzed.

RESULTS

H&E staining revealed reduction in the number of motor neurons which occurred in two phases (between 0 and 10 h and between 48 and 120 h of reperfusion), as well as development of inflammation in spinal cord sections during the reperfusion period, reaching a peak at 48 h. TUNEL reaction was negative for apoptotic neurons at any time point.

CONCLUSIONS

In this porcine model, we demonstrated that, after 45 min of thoracoabdominal aortic occlusion, motor neuron death seems to occur in two phases (immediate and delayed). Inflammation was a subsequent event of transient prolonged spinal cord ischemia and possibly a major contributor of delayed neuronal death. Using TUNEL straining we found no evidence of neuronal apoptosis at any time point of reperfusion.

A tumor necrosis factor receptor 1-dependent conversation between central nervous system-specific T cells and the central nervous system is required for inflammatory infiltration of the spinal cord

We examined the role of tumor necrosis factor receptor 1 (TNFR1) in inflammation initiated by the adoptive transfer of central nervous system (CNS)-specific Th1 cells in experimental autoimmune encephalomyelitis, a murine model of multiple sclerosis. This adoptive transfer paradigm eliminates the confounding effects of bacterial adjuvants in the analysis of inflammation. We found that although T cells could reach the meninges and perivascular space in the absence of TNFR1, recruitment of other inflammatory cells from the blood was dramatically reduced. The reduction in the recruitment of CD11b(hi) cells correlated with a dramatic reduction in the production of the chemokines CCL2 (MCP-1) and CXLC2 (MIP-2) in TNFR1-deficient hosts. Bone marrow chimera experiments demonstrated that TNF can be effectively supplied by either the hematopoietic system or the CNS, but the essential TNFR1-responsive cells reside in the CNS. Previous work has demonstrated that microglia produce CCL2, and here we demonstrate that astrocytes and endothelial cells produced CXCL2 in the early stages of inflammation. Therefore, productive inflammation results from a conversation, or mutually responding signals, between the initiating T cells and cells in the parenchyma of the spinal cord.

Biliverdin reductase, a major physiologic cytoprotectant, suppresses experimental autoimmune encephalomyelitis

Oxidative stress plays an important role in the pathogenesis of multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE). Bilirubin is regarded today as a potent antioxidant. Recent studies show that the potent antioxidant actions of bilirubin reflect an amplification mechanism whereby biliverdin reductase (BVR) physiologically regenerates bilirubin in a catalytic cycle. We hypothesized that BVR might prove to be a new effective target for the treatment of free radical-mediated diseases. In this study, we demonstrated that treatment with BVR ameliorated both clinical and pathological signs of EAE more efficiently than treatments with traditional antioxidant enzymes. In vitro, interference with cellular BVR activity by siRNA elicited greater increases in reactive oxygen species and cell death than interference with the activities of other antioxidant enzymes. Further studies showed that BVR surpasses other enzymes by the multifactorial functions of its only end product, bilirubin, including anti-complement activity, and an activity that inhibits antibody-dependent cell-mediated cytotoxicity of lymphocytes. Since BVR regenerates bilirubin in a redox cycle without significantly increasing the concentration of bilirubin, our results suggest that BVR may represent a novel strategy for the treatment of multiple sclerosis and other oxidative stress-mediated diseases.

Molecular control of physiological and pathological T-cell recruitment after mouse spinal cord injury

The intraspinal cues that orchestrate T-cell migration and activation after spinal contusion injury were characterized using B10.PL (wild-type) and transgenic (Tg) mice with a T-cell repertoire biased toward recognition of myelin basic protein (MBP). Previously, we showed that these strains exhibit distinct anatomical and behavioral phenotypes. In Tg mice, MBP-reactive T-cells are activated by spinal cord injury (SCI), causing more severe axonal injury, demyelination, and functional impairment than is found in non-Tg wild-type mice (B10.PL). Conversely, despite a robust SCI-induced T-cell response in B10.PL mice, no overt T-cell-mediated pathology was evident. Here, we show that chronic intraspinal T-cell accumulation in B10.PL and Tg mice is associated with a dramatic and sustained increase in CXCL10/IP-10 and CCL5/RANTES mRNA expression. However, in Tg mice, chemokine mRNA were enhanced 2- to 17-fold higher than in B10.PL mice and were associated with accelerated intraspinal T-cell influx and enhanced CNS macrophage activation throughout the spinal cord. These data suggest common molecular pathways for initiating T-cell responses after SCI in mice; however, if T-cell reactions are biased against MBP, molecular and cellular determinants of neuroinflammation are magnified in parallel with exacerbation of neuropathology and functional impairment.

MAGNETIC RESONANCE IMAGING CHARACTERISTICS OF ASCENDING HEMORRHAGIC MYELOMALACIA IN A DOG

A 4-year-old neutered female terrier-cross was evaluated for an acute onset of paraplegia. Utilizing magnetic resonance (MR) imaging, the cause of the neurologic deficits was determined to be a lumbar intervertebral disc extrusion. The MR study additionally demonstrated parenchymal hyperintensity on T2-weighted images and similarly located diffuse hypointensity on gradient echo images, cranial and caudal to the compressive extradural lesion. Hemorrhagic myelomalacia was suspected based on these MR characteristics, which was subsequently confirmed surgically and histopathologically.

Elevated IL-6 and TNF- levels in patients with ALS: Inflammation or hypoxia?

Abnormal levels of interleukin (IL)-6 were described in patients with ALS, related to an inflammatory process. The authors compared IL-6 and tumor necrosis factor alpha (TNF-alpha) levels in CSF and sera from 10 hypoxemics and 10 normoxemics patients with ALS to those of 10 hypoxemics and 10 normoxemics neurologic controls. The same pattern exists in patients with ALS and controls: the highest levels are found in hypoxic conditions and undetectable levels are found in normoxemic conditions. Elevated IL-6 levels in ALS could correspond to a normal response to hypoxemia.

Enlargement of the spinal cord: inflammation or neoplasm?

Intramedullary spinal tumours are uncommon lesions that can cause significant difficulties in the differential diagnosis between inflammatory diseases such as multiple sclerosis and acute disseminated encephalomyelitis, and vascular malformations or neoplasms. We report five cases in which the history and the clinical symptoms suggested an inflammatory process of the spinal cord but the MRI characteristics were those of neoplastic lesions. Both non-neoplastic and neoplastic intramedullary lesion may have very similar symptoms, and even CSF abnormalities, but in every one of our cases, a more detailed history and longer observation of the clinical course would have led to the correct diagnosis; in such problem cases, empirical treatment and a follow-up MRI after a month's observation would be a more prudent approach providing that the patient is not rapidly deteriorating.

Axon loss is responsible for chronic neurological deficit following inflammatory demyelination in the rat

Axonal loss is now considered a consistent feature of MS pathology and evidence suggests that its accumulation may be the pathological correlate for the development of irreversible disability. In this study, we investigated the features of axonal loss in myelin autoimmunity and tested the hypothesis that loss of axons determines permanent neurological impairment in a model of inflammatory demyelination that closely mimics the pathology and course of MS. EAE was induced in DA rats by injection of recombinant mouse MOG with IFA. Animals that developed progressive EAE were killed at several time points after disease onset and animals that followed a chronic relapsing-remitting course of EAE were killed at approximately 4 months, exhibiting varying degrees of residual disability. Toluidine blue staining of semithin sections and immunohistochemistry for OX-42 were used to quantify demyelination, remyelination, inflammation and axonal loss in the spinal cord of MOG-EAE rats. In progressive EAE, the degree of axon loss, demyelination and inflammation all correlated significantly with clinical severity scores and a causative role for macrophages in the pathogenesis of axonal injury is suggested. However, in the chronic stage of relapsing-remitting EAE, in rats having suffered a variable number of relapses, only axonal loss correlated significantly with clinical severity scores. In addition, both axonal loss and clinical severity scores correlated with the number of relapses. These findings imply that secondary, or 'bystander', axonal loss is the main determinant of irreversible neurological disability in MOG-EAE and make the model a useful tool for the investigation of mechanisms of axonal loss and the evaluation of the benefits of neuroprotective therapies under conditions of antibody-mediated inflammatory demyelination.

[Brachial plexitis and myelitis and herpes-zoster lumbar plexus disorder in patient treated with infliximab]

Infliximab, a chimeric monoclonal antibody, is a TNF-a inhibitor approved for use in refractory rheumatoid arthritis and Crohn s disease. We present the case of a patient affected by severe rheumatoid arthritis who was successfully treated with infliximab. She suffered diverse neurological complications: brachial plexitis, asymptomatic thoracic myelitis with extensive lesions in MRI study, and herpes zoster lumbar plexitis. We review the neurological adverse effects of infliximab (aseptic meningitis, opportunistic germs infections, disseminated herpes zoster) and focus in their potential adverse effect to induce central and peripheral nervous system demyelination.

Severe tick borne encephalitis with simultaneous brain stem, bithalamic, and spinal cord involvement documented by MRI

A case of tick borne encephalitis (TBE) is reported, with simultaneous brain stem, spinal cord, and bilateral thalamic involvement confirmed by magnetic resonance imaging (MRI). After exposure to a TBE endemic region, the patient developed a biphasic clinical course with initial flu-like symptoms followed by a severe brain stem syndrome. The diagnosis of TBE was confirmed serologically. Repeated MRI scans showed brain stem, bithalamic, and spinal cord involvement. The outcome was favourable. TBE cases with concomitant myelitis tend to have a more severe clinical course and more likelihood of needing intensive care support. They should therefore be identified early in order to be prepared for life threatening respiratory complications.

Characterization of late radiation effects in the rat thoracolumbar spinal cord by MR imaging using USPIO

The aim of this study was to detect late radiation effects in the rat spinal cord using MR imaging with ultra-small particles of iron oxide (USPIO) contrast agent to better understand the development of late radiation damage with emphasis on the period preceding neurological signs. Additionally, the role of an inflammatory reaction was assessed by measuring macrophages that internalized USPIO. T2-weighted spin echo MR measurements were performed at 7T in six rats before paresis was expected (130-150 days post-irradiation, early group), and in six paretic rats (150-190 days post-irradiation, late group). Measurements were performed before, directly after and, only in the early group, 40 h after USPIO administration and compared with histology. In the early group, MR images showed focal regions in grey matter (GM) and white matter (WM) with signal intensity reduction after USPIO injection. Larger lesions with contrast enhancement were located in and around edematous GM of three animals of the early group and five of the late group. Forty hours after injection, additional lesions in WM, GM and nerve roots appeared in animals with GM edema. In the late paretic group, MR imaging showed WM necrosis adjacent to areas with large contrast enhancement. In conclusion, detection of early focal lesions was improved by contrast administration. In the animals with extended radiation damage, large hypo-intense regions appeared due to USPIO, which might be attributed to blood spinal cord barrier breakdown, but the involvement of blood-derived iron-loaded macrophages could not be excluded.

The pathology of human spinal cord injury: defining the problems

This article reviews the pathology of human spinal cord injury (SCI), focusing on potential differences between humans and experimental animals, as well as on aspects that may have mechanistic or therapeutic relevance. Importance is placed on astrocyte and microglial reactions. These cells carry out a myriad of functions and we review the evidence that supports their beneficial or detrimental effects. Likewise, vascular responses and the role of inflammation and demyelination in the mechanism of SCI are reviewed. Lastly, schwannosis is discussed, highlighting its high frequency and potential role when designing therapeutic interventions. We anticipate that a better understanding of the pathological responses in the human will be useful to investigators in their studies on the pathogenesis and therapy of SCI.

West Nile encephalitis and myelitis

PURPOSE OF REVIEW

This article will review the recent experience with West Nile virus encephalitis and myelitis.

RECENT FINDINGS

In the summer of 2003, the majority of cases of West Nile virus infection in the United States were reported from the western states. The transmission of West Nile virus through blood transfusion and organ transplantation was recognized and blood collection agencies implemented West Nile virus nucleic acid-amplification tests to identify infected donors. Intrauterine transmission of West Nile virus infection was reported. The identification of West Nile virus immunoglobulin M in cerebrospinal fluid is the recommended test to document central nervous system infection, but this test may not be positive in spinal fluid collected less than 8 days after the onset of symptoms. Serial samples of cerebrospinal fluid may be required to identify the antibodies. A clinical trial got underway to evaluate the efficacy of human immunoglobulin with high titers of antibodies to West Nile virus in the therapy of West Nile virus encephalitis and myelitis.

SUMMARY

In the summer of 2003, the majority of cases of West Nile virus infection in the United States were reported from states west of the Mississippi river. The identification of West Nile virus IgM in CSF is the recommended test to document CNS infection. A single serum antibody titer is an unreliable test of recent infection.

Painful legs and moving toes syndrome associated with herpes zoster myelitis

A 75-year-old woman developed painful legs and moving toes syndrome (PLMT) 16 months after the onset of herpes zoster (HZ) myelitis. Although the scattered extensive lesions due to HZ myelitis were observed to be eccentric near the posterior horn on MRI, these changes had disappeared upon the development of PLMT. Combined median and tibial nerve somatosensory evoked potentials demonstrated abnormal findings only in the tibial nerve stimuli, suggesting that a severe alteration occurred in the somatosensory fibers coming selectively from the lower legs. These findings suggest plasticity in the ascending somatosensory pathway including the posterior horn cells, probably involving the interneuron networks, for the lower legs may underlie the development of PLMT associated with HZ myelitis.

Histopathologic Effects of Discitis on Neural Tissues

To determine the cause of neurologic symptoms and signs seen in discitis, the neural histopathologic effects of discitis were investigated in an experimental study carried out on rats. Groups of seven rats each had their intervertebral discs inoculated with either Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, or a control solution. Histopathologic examinations of the spinal cord and nerve roots were performed after 3 weeks. On histopathologic examination, vacuolar myelopathy in the spinal cord and vacuolar neuropathy within the nerve roots near the junction with the spinal cord were found. The severity and form of vacuolar myelopathy varied according to the bacteria used for inoculation. The myelopathy and neuropathy seen in this rat model of bacterial discitis might be the result of an immunologic mechanism and could be responsible for the neurologic signs and symptoms of discitis in patients.

Primary diagnosis of Whipple’s disease in bone marrow

Whipple's disease (WD) is a chronic systemic inflammatory disease of infectious origin caused by Tropheryma whipplei (TW). Abdominal pain and recurrent diarrhea are usually the main symptoms leading to the suspicion of a primary bowel disease. Systemic manifestations can mimic hematologic disorders. A 49-year-old man presented with fever, weight loss, long-standing arthralgia, and diarrhea. A duodenal biopsy was unremarkable. Bone marrow histology provided no evidence of a malignant hematological disorder but revealed noncaseating granulomas. TW was detected in the bone marrow trephine by polymerase chain reaction. This is the first report to describe TW-associated granulomatous myelitis as the initially recognized organ manifestation of WD, proven at the molecular level. This observation is relevant for the differential diagnosis of patients with systemic symptoms and granulomatous diseases affecting the bone marrow, emphasizing that WD should be considered in cases of unexplained granulomatous myelitis, even when small bowel biopsy specimens are negative.

Neuropathology of the brain and spinal cord in human West Nile virus infection

OBJECTIVE

To describe the histopathology of the brain and spinal cord in human West Nile virus (WNV) infection.

MATERIALS AND METHODS

Single case report, including premortem clinical and laboratory findings, and autopsy.

RESULTS

An 83-year-old female presented with acute confusion, high fevers, dysarthria and generalized subjective weakness, with decreased deep tendon reflexes and weakness on physical examination. Electromyography showed evidence of a sensorimotor axonal polyneuropathy of the right-sided extremities. She became ventilator-dependent and died after a 2-week ICU stay, following withdrawal of life support. WNV infection was confirmed premortem by detection of IgM antibodies from serum and CSF and postmortem by RT-PCR from brain tissue. Examination of the brain parenchyma showed scattered microglial aggregates accompanied by perivascular chronic inflammation. The leptomeninges showed focal lymphocytic infiltrates. Examination of the spinal cord showed lymphocytic infiltrates in nerve roots and within the cord proper, with focal microglial nodules and neuronophagia in the ventral horns. Special stains were negative for a demyelinating process. General autopsy revealed only emphysema and atelectasis.

CONCLUSIONS

The findings in this case suggest direct viral infection of the spinal cord and nerve roots as the mechanism of the flaccid paralysis often observed in patients infected with WNV. Findings are reviewed in comparison with other reports of neuropathologic findings in human WNV infection.

Cytokine-induced enhancement of autoimmune inflammation in the brain and spinal cord: implications for multiple sclerosis

Multiple sclerosis and experimental autoimmune encephalomyelitis (EAE) are autoimmune inflammatory diseases in which cytokines are intimately involved. Here we test the hypothesis that injection of pro-inflammatory cytokines, tumour necrosis factor-alpha (TNFalpha) and interferon gamma (IFNgamma) into the brain of animals in the prodromal phase of EAE significantly enhances inflammation in the central nervous system (CNS). We were particularly interested to learn whether a local increase in cytokines influenced the pathology locally, or more extensively, within the CNS. EAE was induced in female adult Lewis rats. Eight days post-inoculation, TNFalpha or INFgamma was injected into one cerebral hemisphere. Days 11 and 13 post-inoculation (3 and 5 days after the injection of cytokine) inflammation was quantified by the number of perivascular cuffs and the degree of major histocompatibility complex (MHC) class II expression by microglia. Normal animals injected with cytokines, and EAE animals with saline injection served as controls.

RESULTS

microglial activation was increased three- to fourfold in the brain and eightfold in the spinal cord (P </= 0.05); lymphocyte invasion was increased sixfold in the brain and three- to fourfold in the spinal cord (P </= 0.01) following injections of TNFalpha or INFgamma in EAE animals compared with controls. Significant axonal damage was observed in white matter associated with the perivascular cuffs.

CONCLUSION

local changes in the release of pro-inflammatory cytokines within the brain in EAE results in the widespread enhancement of autoimmune inflammation within the brain and cord, and exacerbation of clinical symptoms.

Specificity of Barkhof Criteria in Predicting Conversion to Multiple Sclerosis When Applied to Clinically Isolated Brainstem Syndromes

BACKGROUND

Barkhof criteria have been adopted to demonstrate dissemination in space in the new multiple sclerosis diagnostic criteria because of their high specificity for predicting conversion to multiple sclerosis. One of the 4 Barkhof criteria is the presence of an infratentorial lesion. In clinically isolated syndromes (CIS) of the brainstem (CISB), the infratentorial criterion does not demonstrate dissemination in space, raising the possibility that the criteria may be less specific in CISB, as compared with specificity in other CIS, in which all 4 criteria demonstrate dissemination in space.

OBJECTIVE

To compare the validity indices of Barkhof criteria in CISB with those in other CIS.

DESIGN

Inception cohort with median follow-up of 34 months for CISB and 40 months for other CIS.

SETTING

Institutional ambulatory referral center.

PATIENTS

A sample of 51 patients with CISB and 102 patients with other CIS (46 with myelitis and 56 with optic neuritis) was analyzed. Barkhof criteria, with a cutoff of 3 of 4, were applied to magnetic resonance imaging performed at baseline. Four combinations each containing 3 parameters were also applied, with a cutoff of 2 of 3.

MAIN OUTCOME MEASURE

Specificity of unmodified Barkhof criteria and of the 4 combinations to predict conversion to clinically definite multiple sclerosis.

RESULTS

The specificity of the criteria in CISB was 61% against 73% in other CIS. The combinations that retained the infratentorial lesion parameter had lower specificities in the CISB group; in analysis of the group with other CIS, no such differences were found.

CONCLUSION

The infratentorial lesion criterion is responsible for the lower specificity of Barkhof criteria in CISB.

Cervical myelitis from herpes simplex virus type 1

Although subacute ascending paralysis without sensory involvement is typically evocative of Guillain-Barré syndrome, it can alternatively be due to infection or inflammation of the spinal cord. We describe a 16-month-old female who presented with ascending flaccid paresis after an upper respiratory tract infection. She then developed signs of upper motor neuron involvement of the lower limbs associated with upper motor neuron involvement of the upper limbs. Motor nerve conduction and electromyographic studies of upper limbs demonstrated anterior horn cell involvement. Neuroimaging was consistent with cervical myelitis, and cerebrospinal fluid polymerase chain reaction was positive for herpesvirus-1. Although association with the primary infection of the respiratory tract may be fortuitous, possible neurotropic or hematogenous spread of herpesvirus-1 to the cervical spinal cord cannot be excluded. She then developed signs of upper motor neuron involvement of the lower limbs associatred with lower motor neuron involvement of the upper limbs [corrected].

[Neural damage associated with allergic diseases: pathomechanism and therapy]

We disclosed the occurrences of myelitis with atopic diathesis preferentially affecting the cervical spinal cord in Japan. Recent nationwide survey revealed that this condition occurs throughout Japan. The characteristic features are: (1) young to middle-aged adults with atopic diathesis are affected, (2) stepwise progression and fluctuation of the symptoms are frequent, (3) paresthesia and dysesthesia are the initial and predominant symptoms while severe motor weakness is rare, (4) CSF abnormalities are infrequent and mild, (5) hyperIgEaemia and mite antigen-specific IgE are present in most cases and eosinophilia is present in about half cases, (6) cervical spinal cord is affected most frequently by clinical symptomatology and on MRI. In this condition, plasma exchange is beneficial in about 80% while corticosteroids are effective only in 50%. The spinal cord biopsy specimens demonstrated its neuropathology to be eosinophilic myelitis involving myelin as well as axon. We also found that Hirayama disease is associated with airway allergy such as allergic rhinitis and atopic asthma. In children, poliomyelitis-like illness after acute asthma attacks is well known as Hopkins syndrome. These findings strongly suggest a link between atopic diathesis and spinal cord damage.

[SMON--a model of the iatrogenic disease]

The subacute myelo-optico-neuropathy (SMON) was hazard caused by clioquinol, an antiseptic, prescribed for the treatment of diarrhea and other bowel symptoms. Its overdosing and long-term taking led to the occurrence of SMON, for which physicians should be responsible. Clioquinol, originally a disinfectant powder for external use, was diverted later to a drug for internal use to sterilize the bowel where no intestinal absorption or action after absorption was expected. An annotation on the 6th Revision of the Japan Pharmacopoeia (1954) allowed irregular increase in its dosage depending on the severity of illness. An annotation on the 7th Revision (1961) ignoring the 6 papers published in the 1930's, 1940's or 1950's claimed that its metabolism was poorly known, yet neglected significant side effect and substantial absorption from the intestine. Its characterization as a superficial disinfectant helped the annotators be less interested in its absorption and its internal actions and side effects. Attention paid by clinicians to a polyneuropathy-like syndrome that complicated an uncontrollable hemorrhagic diarrhea (1958) and an encephalomyelitis or a paralysis of the lower half of the body associated with diarrhea or other bowel symptoms (1960, 1961) started the recognition of a new disease. During the dispute induced by the mass occurrence of the disease in several instances postmortem examination with neuropathologic expertise, especially of T. Tsubaki, Y. Toyokura and H. Tsukagoshi (1964), characterized SMON as a non-inflammatory new disease of the spinal cord, optic nerve and peripheral nerve with a pseudo-systemic degeneration of posterior and lateral columns and, therefore played a decisive role in establishing the truth of SMON. The discovery of the green hairy tongue (the tongue coated with green hairs) of SMON by T. Takasu, A. Igata and Y. Toyokura (January 1970) aroused researchers' interest in the green color of SMON and thereby began solving the cause of SMON. The discovery of the green urine in SMON patients by A. Igata, M. Hasebe and T. Tsuji (May 1970) especially facilitated the identification of the green substance in SMON that was achieved by M. Yoshioka and Z. Tamura (June 1970). The green color was derived from a chelate compound of clioquinol with ferric iron. The early epidemiological analysis related clioquinol taking to the occurrence of SMON well enough for the Japanese Government to take an administrative measure for the temporary suspension of selling clioquinol containing drugs and the postponing of their use (September 1970). Extensive and intensive multidisciplinary investigations conducted for the subsequent 20 months led to the conclusion by the SMON Investigation and Research Committee (Head: R. Kono) that the neurological disorders of patients who were diagnosed as SMON for the most part were caused by taking clioquinol (March 1972). Close clinical observation of patients opened a way to recognize a new disease and elucidate its cause. Expert specialized technical knowledge and skills established the firm knowledge of the new disease. The study of SMON began as a personal research and after its achievement was exposed to the public a great many investigators in different fields concerted efforts to solve problems. Both steps were indispensable for completing the study.

Rats and mice exhibit distinct inflammatory reactions after spinal cord injury

Spinal contusion pathology in rats and mice is distinct. Cystic cavities form at the impact site in rats while a dense connective tissue matrix occupies the injury site in mice. Because inflammatory cells coordinate mechanisms of tissue injury and repair, we evaluated whether the unique anatomical presentation in spinally injured rats and mice is associated with a species-specific inflammatory response. Immunohistochemistry was used to compare the leukocytic infiltrate between rats and mice. Microglia/macrophage reactions were similar between species; however, the onset and magnitude of lymphocyte and dendritic cell (DC) infiltration were markedly different. In rats, T-cell numbers were highest between 3 and 7 days postinjury and declined by 50% over the next 3 weeks. In mice, significant T-cell entry was not evident until 14 days postinjury, with T-cell numbers doubling between 2 and 6 weeks. Dendritic cell influx paralleled T-cell infiltration in rats but was absent in mouse spinal cord. De novo expression of major histocompatability class II molecules was increased in both species but to a greater extent in mice. Unique to mice were cells that resembled lymphocytes but did not express lymphocyte-specific markers. These cells extended from blood vessels within the fibrotic tissue matrix and expressed fibronectin, collagen I, CD11b, CD34, CD13, and CD45. This phenotype is characteristic of fibrocytes, specialized blood-borne cells involved in wound healing and immunity. Thus, species-specific neuroinflammation may contribute to the formation of distinct tissue environments at the site of spinal cord injury in mice and rats.

Aetiological diagnosis of brain abscesses and spinal infections: application of broad range bacterial polymerase chain reaction analysis

OBJECTIVE

To evaluate the usefulness of the broad range bacterial rDNA polymerase chain reaction (PCR) method combined with DNA sequencing in the aetiological diagnosis of intracranial or spinal infections in neurosurgical patients.

METHODS

In addition to conventional methods, the broad range bacterial PCR approach was applied to examine pus or tissue specimens from cerebral or spinal lesions in patients treated in a neurosurgical unit for a clinical or neuroradiological suspicion of bacterial brain abscess or spondylitis.

RESULTS

Among the 44 patients with intracranial or spinal lesions, the final diagnosis suggested bacterial disease in 25 patients, among whom the aetiological agent was identified in 17. A causative bacterial species was identified only by the rDNA PCR method in six cases, by both the PCR methodology and bacterial culture in six cases, and by bacterial culture alone in five. All samples in which a bacterial aetiology was identified only by the PCR approach were taken during antimicrobial treatment, and in three patients the method yielded the diagnosis even after >/= 12 days of parenteral treatment. One case also identified by the PCR approach alone involved a brain abscess caused by Mycoplasma hominis, which is not readily cultured by routine methods.

CONCLUSIONS

In patients with brain abscesses and spinal infections, the broad range bacterial rDNA PCR approach may be the only method to provide an aetiological diagnosis when the patient is receiving antimicrobial treatment, or when the causative agent is fastidious.

CBA/J mice infected with Trypanosoma cruzi: an experimental model for inflammatory myopathies

Idiopathic inflammatory myopathies are inflammatory disorders of unknown origin, characterized by muscle weakness. The aim of our study was to establish and characterize an animal model for chronic inflammatory myopathy which would permit investigations of the role of T-cells in chronic myositis as well as of the mechanisms for muscle weakness in chronic inflammatory muscle disorders. CBA/J mice were infected with the protozoan parasite Trypanosoma cruzi. Immunohistochemistry was used to characterize the distribution and composition of inflammatory infiltrates, and demonstrated a chronic focal inflammation comprised mainly of T-cells and macrophages in infected mice. The inflammatory infiltrates were predominantly found in the endomysium and, to a lesser extent, in perivascular areas. CD8(+) T-cells were found to have invaded nonnecrotic muscle fibers. Degenerating muscle fibers were also found, as well as an increased number of central muscle nuclei. The murine model described in this article may be useful in studying certain aspects of idiopathic inflammatory myopathies such as the role of T-cells in chronic muscle inflammation and chronic myocytotoxicity.

Gene profiling in spinal cord injury shows role of cell cycle in neuronal death

Spinal cord injury causes secondary biochemical changes leading to neuronal cell death. To clarify the molecular basis of this delayed injury, we subjected rats to spinal cord injury and identified gene expression patterns by high-density oligonucleotide arrays (8,800 genes studied) at 30 minutes, 4 hours, 24 hours, or 7 days after injury (total of 26 U34A profiles). Detailed analyses were limited to 4,300 genes consistently expressed above background. Temporal clustering showed rapid expression of immediate early genes (30 minutes), followed by genes associated with inflammation, oxidative stress, DNA damage, and cell cycle (4 and 24 hours). Functional clustering showed a novel pattern of cell cycle mRNAs at 4 and 24 hours after trauma. Quantitative reverse transcription polymerase chain reaction verified mRNA changes in this group, which included gadd45a, c-myc, cyclin D1 and cdk4, pcna, cyclin G, Rb, and E2F5. Changes in their protein products were quantified by Western blot, and cell-specific expression was determined by immunocytochemistry. Cell cycle proteins showed an increased expression 24 hours after injury and were, in part, colocalized in neurons showing morphological evidence of apoptosis. These findings suggest that cell cycle-related genes, induced after spinal cord injury, are involved in neuronal damage and subsequent cell death.

Induced adaptive resistance to oxidative stress in the CNS: a discussion on possible mechanisms and their therapeutic potential

The free radical, nitric oxide (NO), is synthesized by mammalian cells and is utilized for normal cellular functions. High levels of NO are released during disease, injury and inflammation. NO at high concentrations more readily combines with other oxidants to form reactive nitrogenous species (RNS), which can wreak havoc on the cell by damaging a variety of cellular targets, such as DNA and proteins, ultimately leading to apoptosis, mutagenesis or carcinogenesis. Cells have natural resistance mechanisms to nitrooxidative stress that are either defective (as can occur in disease), or overwhelmed (as can occur in injury and inflammation). It has been found recently in the CNS that resistance to normally toxic levels of NO can be induced by nontoxic levels of NO and that this induction is correlated with and dependent upon increased levels and activity of the heme-metabolizing enzyme, heme oxygenase-1 (HO-1). HO1-mediated metabolism of heme groups released from NO-damaged proteins leads to a change in the levels of redox-active iron and a release of carbon monoxide (CO) and bilirubin, all of which have been implicated in cellular resistance to oxidative stress. Perhaps one or more of the products of HO1 heme metabolism is involved in induced adaptive resistance or perhaps a heme-independent mechanism is involved. In fact, a variety of possible mechanisms may be involved in induced resistance to NO in the CNS. Ultimately elucidating these mechanisms will enable us to modulate them for therapeutic potential.

Eosinophilic myelitis associated with atopic diathesis: a combined neuroimaging and histopathological study

Histologically proven eosinophilic myelitis has rarely been reported except in connection with parasitism. To clarify its clinicopathological features, we conducted a nationwide survey of biopsy-proven eosinophilic myelitis of unknown cause throughout Japan. Six such cases were collected and studied immunologically and pathologically. All were young to middle-aged men. All showed a protracted and fluctuating course with mild disability for 3-25 (mean 12.5) months before biopsy. Magnetic resonance imaging revealed localized lesions of T2-high and T1-iso signal intensity with a partial gadolinium enhancement in all cases. Cerebrospinal fluid (CSF) examinations were completely normal except for modest pleocytosis in two cases. Eosinophilia was present in the peripheral blood in two cases but was absent from the CSF of all cases. In spite of the chronic nature of the disease, spinal cord pathology revealed very active lesions with marked cell infiltration consisting mainly of CD8(+) T cells and varying numbers of eosinophils in the perivascular areas and the parenchyma. Both the myelin and axons were severely disrupted in all cases. Moreover, eosinophil cationic protein (ECP), an activated eosinophil product, was heavily deposited in the tissues. All but one case had hyperIgEemia and mite antigen-specific IgE in the sera, and two had accompanying atopic disorders. The present study thus revealed idiopathic eosinophilic myelitis to be a localized and persistent inflammation of the spinal cord, with distinct clinicopathological features, that has a possible link to atopic diathesis.

Molsidomine ameliorates experimental allergic encephalomyelitis in Lewis rats

Experimental allergic encephalomyelitis (EAE) is an autoimmune CD4+ T cell-mediated disease of the central nervous system (CNS). Nitric oxide (NO) plays an important role in preventing the development of EAE. Molsidomine (Mol) is a drug used for the treatment of coronary artery disease. Its therapeutic effects are the consequences of NO formation. In this study, we investigated the effects of Mol on EAE development in myelin basic protein (MBP)-immunized Lewis rats. All rats immunized with MBP developed typical clinical signs of acute EAE. In the EAE rats receiving Mol, the severity of clinical signs and the infiltration of inflammatory cells in CNS were clearly reduced. Furthermore, Mol administration significantly reduced the production of interferon-gamma, a Th1 inflammatory cytokine, but increased the production of interleukin-10, a Th2 anti-inflammatory cytokine. Our findings suggest that the administration of the exogenous NO donor Mol is of considerable benefit in limiting the development of EAE and other Th1 cell-mediated inflammatory diseases.

Inflammatory response associated with axonal injury to spinal motoneurons in newborn rats

Axonal injury in peripheral nerve results in massive motoneuron loss during development. The purpose of this study was to examine the response of phagocytic populations (brain macrophages, BMOs, versus microglia) after different types of axonal lesions (distal axotomy or avulsion) in newborn rats. The morphology, spatial location and activation state of these inflammatory cells were observed. Following spinal root avulsion, BMOs were signaled rapidly and specifically to the location of dying motoneurons in the spinal cord. A large number of BMOs were observed around the avulsed motoneurons on the lesioned side of the spinal cord 1 day following the lesion. These BMOs were large, round, and intensely stained by both antibodies against ED1 and OX-42. The number of BMOs decreased by 3 days and disappeared by 5 days after injury. At the same time, reactive microglia appeared in the lesioned area and rapidly reached the peak level by the 5th day following avulsion. These reactive microglia were medium in size with retracted cellular processes and were also intensely stained by both ED1 and OX-42 antibodies. The number and staining intensity of reactive microglia declined sharply by day 7 after the lesion. In contrast, after distal axotomy only microglia but not BMOs were observed in the lesioned area. These microglial cells were small in size with long and fine-branched processes. They were ED1-negative but OX-42-positive.

Identification of the encephalitogenic epitopes of CNS proteolipid protein in BALB/c mice

It was previously shown that BALB/c mice were susceptible to experimental autoimmune encephalomyelitis induced by immunization with proteolipid protein (PLP). To determine the encephalitogenic epitopes of PLP in BALB/c mice, mice were immunized with successively smaller pools of 20-mer peptides spanning the PLP molecule from amino acid 30 to amino acid 206. Immunization with PLP(180-199) resulted in clinical EAE in 9/15 mice (mean max clinical score of 3.3), and immunization with PLP(185-206) induced clinical EAE in 7/21 BALB/c mice (mean maximum score of 3.7). No relapses in disease were observed. No EAE was observed in BALB/c mice immunized with PLP(185-199) (n=15), PLP(178-191) (n=13) or other regions of PLP (n=15). Passive transfer of PLP(180-199)-primed lymph node cells into nai;ve BALB/c mice resulted in EAE (2/2 mice, max score of 4.0). One-micron toluidine blue stained sections from the spinal cord of EAE-affected BALB/c mice revealed features typical of EAE in other strains, including mononuclear cell infiltration, myelin loss, and axonal loss.

Pure optic-spinal form of multiple sclerosis in Japan

We evaluated the clinical and laboratory features of the optic-spinal form of multiple sclerosis (OSMS) with no brain lesions on repeated MRI--termed pure OSMS. By reviewing the medical records of 118 Japanese clinically definite multiple sclerosis patients seen between 1988-1999, we found 10 patients (8.5%), nine of whom were women, with only relapsing optic neuritis (ON) and myelitis (MY) clinically and consistently normal brain MRI during follow-ups of >or=5 years. Three patients suffered severe ON and MY, but the other seven had mild disease (six were graded 1 in the Disability Status Scale). Despite frequent relapses, mild pure OSMS was characterized by younger onset and mild spinal symptoms as in 'benign' classical multiple sclerosis (CMS). MRI often revealed multiple cervico-thoracic cord lesions of variable lengths. Oligoclonal IgG bands (OB) were negative in all cases. HLA-DPB1*0501, whose association with OSMS has been reported, was positive only in six patients (including three patients with severe pure OSMS). Four patients with DRB1*1501-DQB1*0602, to which CMS is closely linked, had mild disease. Though pure OSMS was heterogeneous with regard to clinical severity and human leukocyte antigen (HLA) class II alleles, this form of multiple sclerosis was characterized by a definite female preponderance and negative OB that distinguished it from CMS.

Preservation of neurologic function during inflammatory demyelination correlates with axon sparing in a mouse model of multiple sclerosis

Axonal injury has been proposed as the basis of permanent deficits in the inflammatory, demyelinating disease, multiple sclerosis. However, reports on the degree of injury are highly variable, and the responsible mechanisms are poorly understood. We examined the relationships among long-term demyelination, inflammation, axonal injury, and motor function in a model of multiple sclerosis, in which mice develop chronic, immune-mediated demyelination of the spinal cord resulting from persistent infection with Theiler's virus. We studied two strains of mice, inbred SJL/J and C57BL/6x129 mice deficient in beta(2)-microglobulin and therefore CD8 lymphocytes. After 8 months of disease, SJL mice had considerably worse motor function than beta(2)-microglobulin-deficient mice. Motor dysfunction correlated linearly with the extent of demyelinated lesions in the spinal cord (lesion load) within each strain, but no difference in lesion load was present between strains. Also, the extent of remyelination did not differ between strains. Instead, the disparity in motor deficits reflected differences in the integrity of descending neurons. That is, retrograde labeling of reticulospinal, vestibulospinal, and rubrospinal neurons, although reduced in all chronically diseased mice, was two to seven times higher in beta(2)-microglobulin-deficient mice. The labeling was superior in beta(2)-microglobulin-deficient mice despite the fact that lesion expanse and therefore the number of axons traversing lesions were similar in both strains. Thus, by all criteria axons were equivalently demyelinated in SJL and beta(2)-microglobulin-deficient mice, but the extent of axonal injury differed significantly. These results indicate that mechanisms of demyelination and axonal injury are at least partly separable, and are consistent with the hypothesis that cytotoxic CD8 lymphocytes may selectively injure demyelinated axons. Additionally, the data suggest that axonal injury obligatorily results from chronic inflammatory demyelination and significantly contributes to neurological deficits.

The neuropathological and behavioral consequences of intraspinal microglial/macrophage activation

Activated microglia and macrophages (CNS macrophages) have been implicated in the secondary or "bystander" pathology (e.g. axon injury, demyelination) that accompanies traumatic or autoimmune injury to the brain and spinal cord. These cells also can provide neurotrophic support and promote axonal regeneration. Studying the divergent functional potential of CNS macrophages in trauma models is especially difficult due to the various degradative mechanisms that are initiated prior to or concomitant with microglial/macrophage activation (e.g. hemorrhage, edema, excitotoxicity, lipid peroxidation). To study the potential impact of activated CNS macrophages on the spinal cord parenchyma, we have characterized an in vivo model of non-traumatic spinal cord neuroinflammation. Specifically, focal activation of CNS macrophages was achieved using stereotaxic microinjections of zymosan. Although microinjection does not cause direct mechanical trauma, localized activation of macrophages with zymosan acts as an "inflammatory scalpel" causing tissue injury at and nearby the injection site. The present data reveal that activation of CNS macrophages in vivo can result in permanent axonal injury and demyelination. Moreover, the pathology can be graded and localized to specific white matter tracts to produce quantifiable behavioral deficits. Further development of this model will help to clarify the biological potential of microglia and macrophages and the molecular signals that control their function within the spinal cord.

Differentiation of multiple sclerosis from other inflammatory disorders and cerebrovascular disease: value of spinal MR imaging

PURPOSE

To determine the value of magnetic resonance (MR) imaging in the spinal cord to differentiate multiple sclerosis (MS) from other inflammatory disorders and cerebrovascular diseases (together, other neurologic disease [OND]).

MATERIALS AND METHODS

The study population included 66 patients with OND and 25 patients with MS, who were matched for age, sex, and symptom duration or severity. Brain MR imaging included gadolinium-enhanced T1-weighted and dual-echo T2-weighted spin-echo sequences to assess the number, size, and appearance of lesions, contrast enhancement, and compatibility with diagnostic criteria for MS. Spinal cord MR imaging included cardiac-triggered gadolinium-enhanced sagittal T1-weighted spin-echo and dual-echo T2-weighted sequences to assess the general appearance (normal, focal lesion, diffuse abnormality) and number or size of focal lesions. Images obtained in MS and OND patients were compared. Specificity, sensitivity, accuracy, and positive and negative predictive values with MR images were calculated.

RESULTS

Brain images were abnormal in all MS patients and in 65% of OND patients. Abnormal cord images were found in 92% of MS and 6% of OND patients. The combination of brain and spinal cord images increased accuracy of diagnosis compared with use of brain images alone.

CONCLUSION

In contrast to MS, cord lesions are very uncommon in OND. This finding can help differentiate these disorders.

Spinal cord injury induces expression of RGS7 in microglia/macrophages in rats

RGS proteins regulate G protein-mediated signalling pathways through direct interaction with the Galpha subunits and facilitation of GTP hydrolysis. An RGS subfamily consisting of RGS 6, 7, 9, and 11 also interacts with the G protein beta subunit Gbeta5 via a characteristic Ggamma-like domain. Thus far, these complexes were found only in neurons, with RGS7 being the most widely distributed in the brain. Here we confirm the expression of RGS7 in spinal neurons and show as a novel finding that following an experimental spinal cord injury in rats, expression of RGS7 is induced in a subpopulation of other cells. Immunofluorescent confocal microscopy using a series of cell specific antibodies identified these RGS7 positive cells as activated microglia and/or invading peripheral macrophages. To rule out interference from the adjacent neurons and confirm the presence of RGS7-Gbeta5 complex in inflammatory cells, we performed immunocytochemistry, RT-PCR, Western blot, and immunoprecipitation using microglial (BV2) and peripheral macrophage (RAW) cell lines. Expression of RGS7 mRNA and protein are nearly undetectable in non-stimulated BV2 and RAW cells, but remarkably increased after stimulation with LPS or TNF-alpha In addition, RGS7-positive cells were also found in the perinodular rim in the rat spleen. Our findings show that RGS7-Gbeta5 complex is expressed in immunocompetent cells such as resident microglia and peripheral macrophages following spinal cord injury. This expression might contribute to the post-traumatic inflammatory responses in the central nervous system.

Gene expression profiling of acute spinal cord injury reveals spreading inflammatory signals and neuron loss

We have completed the first large-scale gene expression study of acute spinal cord injury (SCI) in rat. Oligonucleotide microarrays containing 1,200 gene-specific probes were used to quantify mRNA levels, relative to uninjured controls, in spinal cords injured using a standard contusion model. Our results revealed a marked loss of neuron-specific mRNAs at the injury site. The surviving cells showed a characteristic inflammatory response that started at the injury site and spread to the distal cord. Changes in several mRNA levels were associated with putative regenerative responses in the spinal cord. Notably, phosphodiesterase 4, nestin, glia-derived neurite promoting factor, and GAP-43 mRNAs increased significantly. Other mRNAs clustered temporally and spatially with these regeneration-associated genes. Thus we have described global patterns of gene expression following acute SCI, and we have identified targets for future study and possible therapeutic intervention.

Hepatitis B vaccine related-myelitis?

We present four incidental cases that developed partial myelitis following the administration of hepatitis B vaccine in 1998. The first two cases, a 33-year-old man and a 42-year-old woman developed progressive sensory symptoms without motor involvement within 4 weeks following the vaccination. Their magnetic resonance imaging (MRI) disclosed similar lesions consistent with myelitis at their cervical spinal cord. A comparable inflammatory lesion was seen at the T9-T10 levels of the spinal cord in the third case, who was a 40-year-old woman presenting with numbness in her legs and urinary retention following the vaccination. The fourth case who was a 42-year-old woman, presented with sensory symptoms in her left extremities, which developed 3 months after the vaccination. Her MRI showed a hyperintense lesion at C6. She also had two tiny lesions in her cranial MRI. In all cases, there was no history of preceding infections and no clinical evidence suggestive of any other disorders that may cause myelopathy. All patients recovered completely within 3 months with the exception of the third patient who developed new neurological symptoms after 12 months. Similar clinical and imaging presentation of myelitis following hepatitis B vaccination within a 1 year period with no other demonstrable clinical and laboratory evidence for any other disorder raise the probability of a causal link between these two events.

[Neuropathology of longstanding subacute myelo-optico-neuropathy (SMON): an autopsy case of SMON with duration of 28 years]

The present case, 78-years-old female, had been troubled with SMON during 28 years, and was suddenly died from cerebral hemorrhage. The neuropathology characteristic for SMON could not be revealed in the spinal cord on routine histological preparations. There were decreasing number of immunopositive granules in the nucleus gracilis of medulla oblongata for synaptophysin, and in the marginal zone of the lumbar dorsal horn for substance P. These findings showed the presence of tractus gracilis degeneration and the disappearance of nociceptive fibers from the dorsal roots, respectively. To elucidate the histopathological changes of the spinal cord in long standing cases with SMON, the 11 cases reported were reviewed. The mean duration from the onset to death was 22.8 years(16 to 33 years). The mean age was 76.3 years old(54 to 92), and the 10 cases were female. All cases showed sensory impairment of the lower extremities, while deep tendon reflex exaggerated was seen in 7 cases. There were nine cases involving dorsal funiculi degeneration of the spinal cord, in contrast the lateral funiculi alternation were noticed in only two cases. It was considered that the corticospinal tract alteration becomes undiscernible during the long course, although the dorsal funiculi degeneration remained.

Chemokine antagonist infusion promotes axonal sparing after spinal cord contusion injury in rat

Spinal cord injury produced by mechanical contusion causes the onset of acute and chronic degradative events. These include blood brain barrier disruption, edema, demyelination, axonal damage and neuronal cell death. Posttraumatic inflammation after spinal cord injury has been implicated in the secondary injury that ultimately leads to neurologic dysfunction. Studies after spinal cord contusion have shown expression of several chemokines early after injury and suggested a role for them in the ordered recruitment of inflammatory cells at the lesion site (McTigue et al. [1998] J. Neurosci. Res. 53:368-376; Lee et al., [2000] Neurochem Int). We have demonstrated previously that infusion of the broad-spectrum chemokine receptor antagonist (vMIPII) in the contused spinal cord initially attenuates leukocyte infiltration, suppresses' gliotic reaction and reduces neuronal damage after injury. These changes are accompanied by increased expression of bcl-2, the endogenous apoptosis inhibitor, and reduced neuronal apoptosis (Ghirnikar et al. [2000] J. Neurosci. Res. 59:63-73). We demonstrate that 2 and 4 weeks of vMIPII infusion in the contusion-injured spinal cord also results in decreased hematogenous infiltration and is accompanied by reduced axonal degeneration in the gray matter. Luxol fast blue and MBP immunoreactivity indicated reduced myelin breakdown in the dorsal and ventral funiculi. Increased neuronal survival in the ventral horns of vMIPII infused cords was seen along with increased bcl-2 staining in them. Immunohistochemical identification of fiber phenotypes showed increased presence of calcitonin gene related peptide, choline acetyl transferase and tyrosine hydroxylase positive fibers as well as increased GAP43 staining in treated cords. These results suggest that sustained reduction in posttraumatic cellular infiltration is beneficial for tissue survival. A preliminary report of this study has been published (Eng et al. [2000] J. Neurochem. 74(Suppl):S67B). In contrast to vMIPII, infusion of MCP-1 (9-76), a N-terminal analog of the MCP-1 chemokine showed only a modest reduction in cellular infiltration at 14 and 21 dpi without significant tissue survival after spinal cord contusion injury. Comparing data on tissue survival obtained with vMIPII and MCP-1 (9-76) further validate the importance of the use of broad-spectrum antagonists in the treatment of spinal cord injury. Controlling the inflammatory reaction and providing a growth permissive environment would enhance regeneration and ultimately lead to neurological recovery after spinal cord injury. J. Neurosci. Res. 64:582-589, 2001. Published 2001 Wiley-Liss, Inc.

MRI in Lyme disease of the spinal cord

We report a case of Lyme myelitis in a 31-year-old man, presenting with a conus medullaris syndrome. MRI demonstrated contrast enhancement on the pial surface of the lower thoracic cord and conus medullaris. Elevated blood immunoglobulins and IgM antibodies against Borrelia burgdorferi in the cerebrospinal fluid (CSF) were found. Leptomeningitis may be the first stage of spinal infection in Lyme disease, preceding parenchymal infection leading to myelitis. Vasculitis is probably the major mechanism. MRI findings are nonspecific and the diagnosis is given by serum and CSF analyses. Early treatment with antibiotics and high doses steroids may result in complete recovery, as in this case.