Atypical clinical presentation mimicking stroke in an adult patient caused by a rare diffuse leptomeningeal glioneuronal tumour.

A diffuse leptomeningeal glioneuronal tumours (DLGNT) are very rare tumours of the central nervous system, typically characterized by enhancement of subarachnoid space with cystic lesions, diffuse leptomeningeal infiltration, and no primary mass. We report an atypical clinical presentation of DLGNT. A 48-year-old male was admitted to hospital with symptoms of ischaemic stroke. Magnetic resonance imaging of the head revealed contrast enhancement of the meninges and other parts of the brain. A stereotactic frame biopsy was performed on the patient, which revealed the DLGNT. Diffuse leptomeningeal glioneuronal tumours are mostly seen in individuals less than 18 years old and are characterized by slow growth and low-grade histological appearance. Diffuse leptomeningeal glioneuronal tumours can be aggressive in adults.

Ultrastructure of mitochondria and damage to small blood vessels in siblings with the same mutation in the NOTCH 3 and coexisting diseases.

We performed ultrastructural studies of mitochondria and evaluated the appearance of small blood vessels of three middle-aged siblings affected by the same mutation in the NOTCH3 gene, causing CADASIL. CADASIL pathognomonic features include granular osmiophilic material (GOM), which we observed. GOMs were located in damaged and thickened basement membranes (BM) of capillaries and arterioles. Our patients were also burdened by type II diabetes (first patient), impaired glucose metabolism (second patient), and hypertension (third patient). The ultrastructure of the capillaries in the first and second patients differed from the third patient. In diabetes/impaired glucose metabolism patients (first and second patients), we observed: pathologies of mitochondria in damaged endothelium and pericytes of capillaries; extremely thickened (BM) with visible remains of vascular cells; well-preserved GOMs anchored in the rebuilt capillary extracellular matrix. We identified degenerated or vestigial small blood vessels of skeletal muscles in the first patient. The capillary damage in the third patient (with hypertension) was milder compared to the diabetes/impaired glucose metabolism patients. We conclude that in patients with a mutation in the NOTCH3 gene, the co-occurrence of diseases such as type II diabetes/impaired glucose metabolism can cause a multiplication the damages to small blood vessels by modifying/masking the pathogenesis of CADASIL.

An unusual presentation of Listeria monocytogenes rhombencephalitis.

We describe a case of 52-year-old woman with a medical history of Crohn's disease presented abrupt fever, asymmetrical multiple cranial nerve palsies and focal neurological symptoms localized to the brainstem. The patient was initially diagnosed with ischaemic stroke, because of acute clinical course and results of neuroimaging. Cerebrospinal fluid analysis revealed mild infection with negative Gram staining and culture. Final diagnosis of Listeria monocytogenes brainstem infection (rhombencephalitis) was set up on the basis of further clinical course and positive blood cultures. Listerial rhombencephalitis should be kept in mind in immunocompromised adult patients who develop fever, asymmetrical multiple cranial nerve palsies and focal neurological symptoms localized to the brainstem even without typical neuroimaging, cerebrospinal fluid findings and negative cultures. Early diagnosis and adequate antibiotic treatment is of crucial importance.

Dopamine DRD2 polymorphism (DRD2/ANNK1-Taq1A) is not a significant risk factor in writer's cramp.

Writers' cramp is a movement disorder with dystonic co-contraction of fingers and hand during writing and is part of the clinical spectrum of focal dystonias. Previous studies showed reduced striatal dopamine receptor D2 (DRD2) availability in dystonia. The expression of D2 receptors is modulated by a DRD2/ANKK1-Taq1A polymorphism (rs1800497). This study addresses the question of whether the DRD2/ANKK1-Taq1A polymorphism is a risk factor for writer's cramp. We determined the DRD2/ANKK1-Taq1A polymorphism 34 patients with writer's cramp compared to 67 age matched controls. 35.3% of the patients and 31.3% of our controls were assigned to the A1 genotype status (p = .7). Therefore DRD2/ANKK1-Taq1A gene is not a significant risk factor in the evolution of writer's cramp.

Morphological changes of skeletal muscle in spinal and bulbar muscular atrophy (SBMA), Kennedy's disease: a case report.

Spinal and bulbar muscular atrophy (SBMA, Kennedy's disease) is an X-linked recessive disease affecting lower motor neurons. In the present case report, we describe morphological changes in a muscle biopsy obtained from a 62-year-old patient with gynecomastia and with the following neurological symptoms: dysphagia, dysarthria, wasting and fasciculation of the tongue, proximal weakness, fasciculations in the limb muscles, and an absence of all tendon reflexes. Neurogenic alternations were predominantly observed using light and electron microscopy. The angulated atrophic muscle fibers formed bundles. The numerous nuclei were pyknotic or pale, some of them were also ubiquitin positive; they were grouped inside so-called "nuclear sacks". At the ultrastructural level, atrophic muscle fibers revealed disruption and loss of sarcomeres, duplication of Z-line, and rod-like structures. The nuclei, often with irregular shapes, revealed varying degrees of chromatin condensation, from dispersed to highly condensed, like pyknotic nuclei. Occasionally electron-dense inclusions in the nuclei were found. Some myogenic features like hypertrophic muscle fibers and proliferation of connective tissue were also visible. The neurogenic and myogenic pathological changes suggested SBMA, which was confirmed with genetic analysis (trinucleotide CAG (glutamie)-repeat expansion in the androgen-receptor gene).

Endovascular treatment of cervical intramedullary arteriovenous malformation.

Intramedullary arteriovenous malformations (AVMs) in the cervical region are a rare clinical condition. They represent a therapeutic challenge, as the lesions may cause serious functional disorders due to their location within or immediately adjacent to the critical ascending and descending sensorimotor pathways. In this case report, we present a patient with a cervical intramedullary AVM that was treated with endovascular therapy. Our experience suggests that endovascular treatment is an effective and safe method for treating AVMs located in the cervical region of the spinal cord. More studies are needed to establish appropriate treatment protocols depending on the clinical course, the anatomy of the lesion, and the region in which it is found.

Transformation of IDH-wildtype glioblastoma to gliosarcoma with features of osteosarcoma.

Gliosarcoma (GS) is a rare variant of IDH-wildtype glioblastoma. It is classified as grade 4 in the latest WHO CNS classification of both glial and mesenchymal components. Gliosarcoma may arise de novo or secondary from glioblastoma. It occurs in up to 2% of patients diagnosed with glioblastoma. We present a case report of a 51-year-old patient who was initially diagnosed with glioblastoma multiforme, which transformed into secondary gliosarcoma with an osteosarcoma component 16 months after the initial diagnosis. We believe that increasing reporting of secondary gliosarcoma (sGS) will be helpful in understanding, diagnosing and providing more effective treatment for this cancer.

TDP-43 pathology in subacute sclerosing panencephalitis.

Subacute sclerosing panencephalitis (SSPE) is a fatal, slowly progressive brain disorder caused by a mutated measles virus. Both subacute inflammatory and neurodegenerative mechanisms appear to play significant roles in the pathogenesis. TAR DNA-binding protein 43 (TDP-43) inclusions are a common co-pathology in several neurodegenerative disorders with diverse pathogenesis. In the present study, we examined brains of 16 autopsied SSPE patients for the presence of TDP-43 pathology and possible associations with tau pathology. Immunohistochemical staining identified TDP-43 inclusions in 31% of SSPE cases. TDP-43 pathology was widely distributed in the brains, most severely in the atrophied cerebral cortex (temporal and parietal), and most frequently as tangle- and thread-like neuronal cytoplasmic inclusions. It was associated with longer disease duration (>4 years) and tau pathology (all TDP-43-positive cases had tau-positive neurofibrillary tangles). This study demonstrates for the first time an association between TDP-43 pathology and SSPE. The co-occurrence of TDP-43 and tau aggregates and correlation with the disease duration suggest that both pathological proteins are involved in the neurodegenerative process induced by viral inflammation.

Incidence and morphology of secondary TDP-43 proteinopathies: Part 2.

Transactivation (TAR) DNA binding protein 43 kDa (TDP-43) inclusions frequently occur as a comorbid pathology in several neurodegenerative disorders, including Alzheimer's disease, Huntington's disease, Lewy body disease, and progressive supranuclear palsy, and may appear in association with nondegenerative neurological etiology, for example neoplastic, paraneoplastic, traumatic, or infectious. Relationships between various pathological proteins and mechanisms associated with TDP-43-induced neurodegeneration are still not fully understood. Thus, overlap of distinct neuropathological mechanisms frequently leads to greater brain atrophy and a more severe clinical course, suggesting the importance of co-pathologies in ante-mortem diagnosing and treatment. The present review aims to discuss the incidence, morphology, and role of TDP-43 pathology in the context of other dominant, hallmark pathologies, referred to as secondary TDP-43 proteinopathies. The previous part (Part 1) focused on common neurodegenerative diseases, including Alzheimer's disease, Huntington's disease, and Lewy body disease, while the present part (Part 2) discusses TDP-43 pathology in rare neurodegenerative diseases and neurological diseases with nondegenerative etiology.

Influence of SARS-CoV-2 on Adult Human Neurogenesis.

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is associated with the onset of neurological and psychiatric symptoms during and after the acute phase of illness. Inflammation and hypoxia induced by SARS-CoV-2 affect brain regions essential for fine motor function, learning, memory, and emotional responses. The mechanisms of these central nervous system symptoms remain largely unknown. While looking for the causes of neurological deficits, we conducted a study on how SARS-CoV-2 affects neurogenesis. In this study, we compared a control group with a group of patients diagnosed with COVID-19. Analysis of the expression of neurogenesis markers showed a decrease in the density of neuronal progenitor cells and newborn neurons in the SARS-CoV-2 group. Analysis of COVID-19 patients revealed increased microglial activation compared with the control group. The unfavorable effect of the inflammatory process in the brain associated with COVID-19 disease increases the concentration of cytokines that negatively affect adult human neurogenesis.

Large haemorrhage within glioblastoma mimicking haemorrhagic stroke and coexistance of meningioma: a case of collision tumours.

Intracranial collision tumours are rare pathologies in which two distinct neoplasms are found in the same location. We present an unusual case of an intracranial collision tumour composed of meningothelial meningioma (CNS WHO G1) and glioblastoma (IDH-wildtype, CNS WHO G4). This collision tumour was found in a 64-year-old man. This patient was hospitalized urgently due to left-sided hemiparesis. The computed tomography (CT) revealed large multilobar intracranial haemorrhage located in the right hemisphere. The history of hypertension and obesity pointed to the misdiagnosis of a typical haemorrhagic stroke. Despite extensive physiotherapy after initial improvement, the magnetic resonance imaging (MRI) showed signs of a marginal contrast enhancement with a suspicion of a brain tumour. Moreover, the meningioma in the same location was suspected. The neuropathological findings confirmed two neoplasms with fragments of the dura mater infiltrated by malignant glioma cells and small nests of meningothelial cells with psammoma bodies. The presented case is extremely rare showing that more malignant tumour may infiltrate a meningioma. Moreover, this case highlights the clinical observation that glioblastoma may mimic a haemorrhagic stroke. In such cases when pharmacological treatment is not effective, suspicions should be raised about a possible underlying brain tumour.

Acoustic startle responses and prepulse inhibition of acoustic startle responses in Warsaw alcohol high-preferring (WHP) and Warsaw alcohol low-preferring (WLP) rats.

AIMS: An assessment of the acoustic startle response (ASR) and prepulse inhibition (PPI) of ASR in laboratory animals is used to model human anxiety and psychotic states, respectively. The aim of the study was to evaluate ASR and PPI in alcohol-naive male and female Warsaw alcohol high-preferring (WHP) and Warsaw alcohol low-preferring (WLP) rats. METHODS: ASR and PPI were assessed in two separate experiments by using the SR-LAB apparatus (San Diego Instruments, San Diego, CA, USA). In the ASR session, animals (n = 13-16 rats per group) were exposed to startling stimuli of different intensities (72, 84, 98, 112 and 124 dB) in a random order. In the PPI session, prepulse stimuli (78, 81, 84 and 90 dB) preceded a pulse startling stimulus (120 dB) in a random order. The background white noise was set at 70 dB. PPI was calculated according to the formula: [(startle amplitude in pulse alone trials-startle amplitude in prepulse-and-pulse trials)/startle amplitude in pulse alone trials] 100%. RESULTS: The WHP males exhibited higher startle amplitudes in response to 112 dB stimuli when compared with their WLP counterparts. The WHP females showed higher startle reactivity to 112 and 124 dB stimuli when compared with the WLP females. There were no differences between the WHPs and WLPs in PPI of ASR. CONCLUSION: The results of the present study suggest that exaggerated startle responses can be a physiological/behavioral marker of a propensity to abuse alcohol.

DNA Hydroxymethylation in High-Grade Gliomas.

BACKGROUND: Since the new World Health Organization (WHO) classification of nervous system tumors (2016, revised, 4th edition) has been released, gliomas are classified depending on molecular and genetic markers in connection with histopathology, instead of histopathology itself as it was in the previous classification. Over the last years, epigenetic analysis has taken on increased importance in the diagnosis and treatment of different cancers. Multiple studies confirmed that deoxyribonucleic acid (DNA) methylation and hydroxymethylation play an important role in the regulation of gene expression during carcinogenesis. METHODS: In this review, we aim to present the current state of knowledge on DNA hydroxymethylation in human high-grade gliomas (WHO grades III and IV). RESULTS: The correlation between DNA hydroxymethylation and survival in glioblastoma multiforme (GBM) patients was evaluated by different studies. The majority of them showed that the expression of 5-hydroxymethylcytosine (5-hmC) and ten-eleven translocation (TET) enzymes were significantly reduced, sometimes almost undetectable in high-grade gliomas in comparison with the normal brain. A decreased level of 5-hmC was associated with poor survival in patients, but high expression of the TET3 enzyme was related to a better prognosis for GBM patients. This points to the relevance of DNA hydroxymethylation in molecular diagnostics of human gliomas, including survival estimation or differentiating patients in terms of response to the treatment. CONCLUSION: Future studies may shed some more light on this epigenetic mechanism involved in the pathogenesis of human high-grade gliomas and help develop new targeted therapies.

Incidence and morphology of secondary TDP-43 proteinopathies: Part 1.

Transactive response DNA binding protein of 43 kDa (TDP-43) is considered to play an essential role in the pathogenesis of frontotemporal lobar degeneration and amyotrophic lateral sclerosis. Growing body of evidence indicate that pathological TDP-43 inclusions frequently occur in the context of other distinctive hallmark pathologies, referred to as secondary TDP-43 proteinopathies. Comorbid TDP-43 pathology is well-documented in several neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, multiple system atrophy, or progressive supranuclear palsy. It may also appear as a consequence of less obvious disease etiologies, i.e. post-traumatic (chronic traumatic encephalopathy), neoplastic (pilocytic astrocytoma), or post-infectious (post-encephalitic parkinsonism). The aim of the present review was to evaluate the incidence, morphology, and role of TDP-43 pathology in the secondary TDP-43 proteinopathies. This article (Part 1) discussed TDP-43 pathology in more common neurodegenerative diseases, including Alzheimer's disease, Lewy body disease, Huntington's disease, multiple system atrophy, corticobasal degeneration, and progressive supranuclear palsy. A follow-up article (Part 2) will describe abnormal TDP-43 changes in rare neurodegenerative diseases or neurological diseases with nondegenerative etiology.

Acute disseminated encephalitis in an adult patient addicted to heroin. Neuropathological, neuroradiological and clinical features.

Acute disseminated encephalomyelitis (ADEM) is an immune demyelinating central nervous system (CNS) disorder, characterized by monophasic new onset neurological symptoms including encephalopathy, combined with neuroradiological evidence of multifocal demyelination. ADEM is extremely rarely diagnosed and is much more common in children and adolescents than in adults. The aim of this study is to present an extremely rare case of ADEM in a heroin-addicted patient with a very difficult diagnostic course. The results of the magnetic resonance imaging (MRI) examination in this patient were inconclusive. Fungal abscesses or inflammatory lesions of an unclear nature were suspected especially in a patient with impaired immunodeficiency. In view of the constantly deteriorating condition of the patient with disturbed consciousness and the unclear aetiology, the lack of effective treatment, a decision was made to perform a bilateral stereotactic biopsy and aspiration of brain abnormalities in order to obtain a neuropathological specimen and begin with the causal treatment. Neuropathological examination revealed the presence of Creutzfeldt-Peters cells characteristic of ADEM. Treatment with methylprednisolone significantly improved the patient's general and neurological condition. To our knowledge, the above case is the first in the world literature in which ADEM has been confirmed by bilateral stereotaxic aspiration for the treatment of symptoms of increased intracranial pressure as a lifesaving procedure. Neuropathological confirmation allowed for the implementation of appropriate treatment, which resulted in complete recovery. Moreover, this case is interesting because ADEM was diagnosed in a patient addicted to heroin, where opportunistic inflammation of a fungal aetiology was considered in the first place.

Atypical clinical presentation of glioblastoma mimicking autoimmune meningitis in an adult.

Glioblastoma (GBM) is the most malignant type of glial tumor associated with a very unfavorable prognosis. Typical radiological features of GBM include the presence of a tumor with irregular contrast-enhancing margins and central necrosis surrounded by a wide area of vasogenic edema. Here, we presented an atypical clinical presentation of GBM mimicking autoimmune meningitis. A 69-years-old previously healthy male was admitted to the emergency room due to signs of increasing cognitive impairment, weight loss, changes in behavior, difficulty in walking, and prolonged episodes of nausea over the past month. An magnetic resonance imaging (MRI) brain scan revealed hyperintense changes of the periventricular area surrounding brain ventricles in T2 and FLAIR, and post-contrast leptomeningeal enhancement and thickening of meninges involving cerebellar sulci. An additional MRI scan of the cervical spine showed an in-core contrastenhancing lesion on the C7-Th1 level as well as leptomeningeal thickening and post-contrast-enhancement around the spinal cord. Various laboratory tests and two stereotactic biopsies were performed with no essential to diagnosis clinical findings. A couple of months after first hospital admission, the patient died. Post-mortem examination of the brain revealed numerous foci of abnormal tissue inside the subarachnoid space, lateral ventricles, and cerebral aqueduct. Histological examination showed diffuse malignant astroglial neoplasm, and diagnosis of glioblastoma NOS WHO G IV was established. Even though the appearance of usual GBM is widely recognizable, one must bear in mind the possibility of unusual presentation. The presented case highlights the diagnostic difficulties of diffuse glioblastoma with atypical clinical presentation.

The spectrum of microvascular ultrastructural changes in the subpopulation of patients with migraine and cerebral white matter hyperintensities on MRI.

INTRODUCTION: Migraine is considered not only as a separate clinical entity but also as a symptom of various brain disorders, including cerebral small vessel diseases. Since cerebral small vessel diseases are usually general angiopathies, evaluation of biopsy material other than brain tissue may help in their diagnosis in vivo. In patients with migraine, brain magnetic resonance imaging (MRI) often shows hyperintense changes in the cerebral white matter. Such changes may indicate the symptomatic nature of migraine and coexisting structural or biochemical vascular abnormalities. MATERIAL AND METHODS: To verify the hypothesis of the symptomatic nature of migraine in patients with abnormal brain neuroimaging, we performed an ultrastructural examination of skin and skeletal muscle vessels in biopsy material from 40 patients with clinically diagnosed migraine and hyperintense white matter lesions on MRI. RESULTS: In 80% of the examined patients, ultrastructural examination showed various pathological changes in the microvessels including abnormalities characteristic of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and elastin disorders, as well as less specific changes such as thickening of the basal lamina, narrowing of the vessel lumen, degeneration of the vessel wall cells, endothelial activation, oncosis-like changes, and the presence of various types of deposits in the vessel wall. In 20% of the examined cases, ultrastructural examination of the vessels was normal. CONCLUSIONS: Patients with migraine and hyperintense cerebral white matter changes on MRI have an increased risk of concomitant microangiopathy. In this group of patients, skin-muscle biopsy allows the identification of cases with coexisting vessel abnormalities.

Neuropathological analysis of the brains of fifty-two patients with COVID-19.

Coronavirus disease 2019 (COVID-19) poses a global challenge to healthcare and society in the early 21st century. We report neuropathological changes in 52 patients aged between 22 years and 88 years (median 58 years) who were infected with the CoV-2 coronavirus. Patients died under various circumstances and had various pre-existing diseases. The inclusion criteria for this study were: positive result for the nasopharyngeal swab for SARS-CoV-2 RNA, diagnosis of pneumonia of SARS-CoV-2 or nucleoproteins of SARS-CoV-2 in pulmonary tissue confirmed by immunohistochemical methods (IHC). Samples from all brain structures and lung specimens were taken for histopathological examinations. Brain and pulmonary samples were stained typically with histological and immunohistochemical methods and small tissue fragments were examined with the transmission electron microscope (TEM). The light and electron microscopy examination confirmed the numerous neuropathological changes in the brains of the patients infected with the CoV-2. Many of these changes were caused by pre-existing diseases of patients and/or by necessary treatment. However, vascular lesions and the inflammatory process seem to be characteristic of the CoV-2 infection. In all of the structures of 52 brains of patients, damage of the vessel walls and morphological feature of the damage to the blood-brain barrier were observed. Lymphocytic and microglial infiltrates, both perivascular and diffuse, were also observed. Hence, the brain changes due to COVID-19 infection, could be called COVID-19 cerebral angiopathy with diffuse inflammation.

Pretreatment with a glutamine synthetase inhibitor MSO delays the onset of initial seizures induced by pilocarpine in juvenile rats.

The contribution of glutamatergic transmission to generation of initial convulsive seizures (CS) is debated. We tested whether pretreatment with a glutamine synthetase (GS) inhibitor, methionine sulfoximine (MSO), affects the onset and progression of initial CS by cholinergic stimulus in juvenile rats. Male rats (24 days old, Sprague Dawley) sequentially received i.p. injections of lithium-carbonate, MSO, methyl-scopolamine, and pilocarpine (Pilo). Pilo was given 150 min after MSO. Animals were continuously monitored using the Racine scale, EEG/EMG and intrahippocampal glutamate (Glu) biosensors. GS activity as measured in hippocampal homogenates, was not altered by MSO at 150 min, showed initial, varied inhibition at 165 (15 min post-Pilo), and dropped down to 11% of control at 60 min post-Pilo, whereas GS protein expression remained unaltered throughout. Pilo did neither modulate the effect of MSO on GS activity nor affect GS activity itself, at any time point. MSO reduced from 32% to 4% the number of animals showing CS during the first 12 min post-Pilo, delayed by ~6 min the appearance of electrographic seizures, and tended to decrease EMG power during ~15 min post-Pilo. The results indicate that MSO impairs an aspect of glutamatergic transmission involved in the transition from the first cholinergic stimulus to the onset of seizures. A continuous rise of extracellular Glu lasting 60 min was insignificantly affected by MSO, leaving the nature of the Glu pool(s) involved in altered glutamatergic transmission undefined.

Encephalomyelitis associated with rheumatoid arthritis: a case report.

Encephalitis/encephalomyelitis in the course of rheumatoid arthritis (RA) remains a matter of debate. We present a case of a patient with encephalomyelitis associated with RA confirmed with post-mortem neuropathological examination. A 68-year-old woman with a long-standing, seropositive history of RA presented progressive disturbances of consciousness. Magnetic resonance imaging (MRI) of the brain and cervical spine revealed an increase of signal intensity on T2-weighted and fluid attenuated inversion recovery (FLAIR) images with corresponding restricted diffusion involving cerebral peduncles, pons, medulla oblongata, and cervical spinal cord and mild contrast-enhancement of the right cerebral peduncle. Extensive radiological and laboratory testing, including autoantibodies to paraneoplastic anti-neuronal and neuronal cell surface antigens, were all negative except for elevated rheumatoid factor. Cerebrospinal fluid (CSF) analysis revealed moderate pleocytosis with mononuclear cell predominance, mildly increased protein level, and negative viral PCRs, bacterial cultures, flow cytometry, and neuronal surface antibodies. Despite intensive treatment with corticosteroids, antibiotics, antiviral drugs, and intravenous immunoglobulin the patient died after 3 months of hospitalization. Post-mortem neuropathological examination revealed numerous, disseminated, heterochronous ischaemic lesions, rarely with haemorrhagic transformation, predominantly in the brainstem, and widespread, diffuse microglia and T-cell infiltrations with neuronal loss and astrogliosis, most severe in the frontal and temporal lobes. Mild, perivascular lymphocyte T infiltrations involved particularly small and medium-sized vessels and were associated with brainstem ischaemic lesions. The neuropathological picture confirmed diagnosis of encephalomyelitis, which together with the clinical course suggested association with RA. Concluding, encepha-lomyelitis due to RA remains a challenging, controversial entity that needs further research and the establishment of effective diagnostic and treatment guidelines.