Heterotypic macrophages/microglia differentially contribute to retinal ischaemia and neovascularisation.

AIMS/HYPOTHESIS: Diabetic retinopathy is characterised by neuroinflammation that drives neuronal and vascular degenerative pathology, which in many individuals can lead to retinal ischaemia and neovascularisation. Infiltrating macrophages and activated retina-resident microglia have been implicated in the progression of diabetic retinopathy, although the distinct roles of these immune cells remain ill-defined. Our aim was to clarify the distinct roles of macrophages/microglia in the pathogenesis of proliferative ischaemic retinopathies. METHODS: Murine oxygen-induced retinopathy is commonly used as a model of ischaemia-induced proliferative diabetic retinopathy (PDR). We evaluated the phenotype macrophages/microglia by immunostaining, quantitative real-time RT-PCR (qRT-PCR), flow cytometry and scRNA-seq analysis. In clinical imaging studies of diabetic retinopathy, we used optical coherence tomography (OCT) and OCT angiography. RESULTS: Immunostaining, qRT-PCR and flow cytometry showed expression levels of M1-like macrophages/microglia markers (CD80, CD68 and nitric oxide synthase 2) and M2-like macrophages/microglia markers (CD206, CD163 and macrophage scavenger receptor 1) were upregulated in areas of retinal ischaemia and around neo-vessels, respectively. scRNA-seq analysis of the ischaemic retina revealed distinct ischaemia-related clusters of macrophages/microglia that express M1 markers as well as C-C chemokine receptor 2. Inhibition of Rho-kinase (ROCK) suppressed CCL2 expression and reduced CCR2-positive M1-like macrophages/microglia in areas of ischaemia. Furthermore, the area of retinal ischaemia was reduced by suppressing blood macrophage infiltration not only by ROCK inhibitor and monocyte chemoattractant protein-1 antibody but also by GdCl3. Clinical imaging studies of diabetic retinopathy using OCT indicated potential involvement of macrophages/microglia represented by hyperreflective foci in areas of reduced perfusion. CONCLUSIONS/INTERPRETATION: These results collectively indicated that heterotypic macrophages/microglia differentially contribute to retinal ischaemia and neovascularisation in retinal vascular diseases including diabetic retinopathy. This adds important new information that could provide a basis for a more targeted, cell-specific therapeutic approach to prevent progression to sight-threatening PDR.

[A case of neurosarcoidosis initially diagnosed as cervical spondylotic myelopathy, leading to diagnosis by gadolinium contrast-enhanced MRI].

A 70-year-old female presented with bilateral numbness in her upper limbs. She was diagnosed with cervical spondylotic myelopathy and underwent cervical laminoplasty. However, there was no significant improvement in sensory disturbance, and at 6 months after surgery, she developed subacute motor and gait disturbance in four extremities. Spinal MRI revealed a long lesion of the spinal cord with edema, and a part of the lesion showed gadolinium contrast enhancement. Bronchoscopy revealed an elevated CD4/8 ratio, and gallium scintigraphy demonstrated an accumulation in the hilar lymph nodes, leading to a diagnosis of neurosarcoidosis. In case of rapid deterioration during the course of cervical spondylotic myelopathy, neurosarcoidosis should be considered as a differential diagnosis, which can be assessed by contrast-enhanced MRI.

Lumbar Subarachnoid-Peritoneal Shunting Deteriorates Superficial Siderosis Associated with a Dural Defect.

Superficial siderosis is a disease in which hemosiderin is deposited under the leptomeninges and subpial layers of hindbrain structures, e.g., the cerebellum, brainstem, and eighth cranial nerve. The main symptoms of superficial siderosis are cerebellar ataxia, hearing loss, cognitive decline, and myelopathy. The activities of daily living of patients with superficial siderosis are severely impaired due to the progressive symptoms. Here, we report a patient with superficial siderosis whose symptoms deteriorated after lumbar subarachnoid-peritoneal (L-P) shunt surgery. She received L-P shunt surgery based on the diagnosis of idiopathic normal pressure hydrocephalus at another hospital. The patient had a history of cervical surgery, and a dural defect was identified at the C4-5 level by a detailed magnetic resonance imaging study. We hypothesized that the L-P shunt reduced cerebrospinal pressure and increased bleeding from the fragile vessels in the dural defect, which might have increased hemosiderin deposition.

A human T-lymphotropic virus-1 carrier who developed progressive multifocal leukoencephalopathy following immunotherapy for sarcoidosis: a case report.

BACKGROUND: Progressive multifocal leukoencephalopathy (PML) is a devastating demyelinating disorder of the central nervous system caused by opportunistic infection of the JC virus (JCV). CASE PRESENTATION: A 58-year-old Japanese woman was admitted to our hospital for aphasia. She had a 5-year history of untreated sarcoidosis and was a human T cell lymphotropic virus-1 (HTLV-1) carrier. Serum angiotensin-converting enzyme, soluble interleukin-2 receptor, lysozyme, and calcium levels were elevated. JCV-DNA was not detected in cerebrospinal fluid by PCR testing. Skin biopsy revealed noncaseating granuloma formation. Bilateral multiple nodular lesions were present on chest X-ray. Brain magnetic resonance imaging showed left frontal and temporal lesions without gadolinium enhancement. As we suspected that systemic sarcoidosis had developed into neurosarcoidosis, we started steroid and infliximab administration. After treatment, the chest X-ray and serum abnormalities ameliorated, but the neurological deficits remained. At 1 month after immunotherapy, she developed right hemiparesis. Cerebrospinal fluid was positive for prototype (PML-type) JCV on repeated PCR testing. Brain biopsy revealed demyelinating lesions with macrophage infiltration, atypical astrocytes, and JCV antigen-positive cells. We diagnosed her with PML and started mefloquine, leading to partial remission. CONCLUSIONS: Sarcoidosis and HTLV-1 infection both affect T cell function, especially CD4+ T cells, and may developped the patient's PML. The comorbidity of sarcoidosis, PML, and HTLV-1 infection has not been reported, and this is the world's first report of PML associated with HTLV-1 infection and sarcoidosis.

[A case of multiple sclerosis with a tumefactive lesion during long-term treatment with fingolimod, leading to decompressive craniotomy].

We report a 57-year-old man with multiple sclerosis since his 30s who was treated with fingolimod for 9 years. He developed left hemiparesis and consciousness disturbance. Brain MRI revealed a mass lesion in the right frontal lobe with gadolinium enhancement. Cerebrospinal fluid examination showed no pleocytosis. The lesion continued to expand after admission, and on the 9th day after admission, decompressive craniectomy and brain biopsy were performed. Brain pathology revealed demyelination in the lesion, leading to the diagnosis of a tumefactive demyelinating lesion. Corticosteroid therapy ameliorated the brain lesion, and we inducted natalizumab. Tumefactive demyelinating lesions requiring decompressive craniotomy are rare, and we report this case for the further accumulation of similar cases.

[Chronic progressive external ophthalmoplegia that could not be diagnosed by biceps muscle biopsy, but was genetically diagnosed by extraocular muscle biopsy].

A 48-year-old Japanese male experienced slowly progressive diplopia. He had no family history and was negative for the edrophonium chloride test. Blood analysis showed elevated lactic acid and pyruvic acid levels, suggesting mitochondrial disease. A muscle biopsy from the biceps brachii was performed, but no pathological or genetical mitochondrial abnormalities were detected. Subsequently, he underwent muscle plication for diplopia in which the right inferior rectus muscle was biopsied. Genetic examination of genomic DNA extracted from the extraocular muscle tissue revealed multiple mitochondrial gene deletions, with a heteroplasmy rate of approximately 35%, resulting in the diagnosis of chronic progressive external ophthalmoplegia. In mitochondrial diseases, the tissue distribution of mitochondria with disease-associated variants in mtDNA should be noted, and it is important to select the affected muscle when performing a biopsy for an accurate diagnosis.

Identifying Hyperreflective Foci in Diabetic Retinopathy via VEGF-Induced Local Self-Renewal of CX3CR1+ Vitreous Resident Macrophages.

Intraretinal hyperreflective foci (HRF) are significant biomarkers for diabetic macular edema. However, HRF at the vitreoretinal interface (VRI) have not been examined in diabetic retinopathy (DR). A prospective observational clinical study with 162 consecutive eyes using OCT imaging showed significantly increased HRF at the VRI during DR progression (P < 0.01), which was reversed by anti-vascular endothelial growth factor (VEGF) therapy. F4/80+ macrophages increased significantly at the VRI in Kimba (vegfa+/+) or Akimba (Akita × Kimba) mice (both P < 0.01), but not in diabetic Akita (Ins2+/-) mice, indicating macrophage activation was modulated by elevated VEGF rather than the diabetic milieu. Macrophage depletion significantly reduced HRF at the VRI (P < 0.01). Furthermore, BrdU administration in Ccr2rfp/+Cx3cr1gfp/+vegfa+/- mice identified a significant contribution of M2-like tissue-resident macrophages (TRMs) at the VRI. Ki-67+ and CD11b+ cells were observed in preretinal tissues of DR patients, while exposure of vitreal macrophages to vitreous derived from PDR patients induced a significant proliferation response in vitro (P < 0.01). Taken together, the evidence suggests that VEGF drives a local proliferation of vitreous resident macrophages (VRMs) at the VRI during DR. This phenomenon helps to explain the derivation and disease-relevance of the HRF lesions observed through OCT imaging in patients.

Gadolinium-enhanced MR improved motion sensitized driven equilibrium (iMSDE) for intracranial vessel imaging in giant cell arteritis.

BACKGROUND: Giant cell arteritis (GCA) generally affects extracranial large and medium-sized vessels. It rarely causes intracranial vessel stenosis, presenting as cerebral infarction (CI). Consequently, accurate diagnosis of CI induced by GCA is often challenging. Improved motion-sensitized driven-equilibrium (iMSDE) is one of the advanced high-resolution magnetic resonance (MR) vessel wall imaging techniques that enables direct visualization of the vessel wall because of a strong reduction in blood flow artifacts, leading to higher quality images. Herein, we effectively used gadolinium-enhanced MR iMSDE imaging to diagnose a patient presenting with recurrent CI due to right intracranial internal carotid artery (ICA) stenosis as GCA. CASE DESCRIPTION: A 64-year-old man with polymyalgia rheumatica for several years and who had experienced CI due to moderate intracranial ICA stenosis one year ago, presented to the emergency room with dysarthria and left hemiparesis. Diffusion-weighted MR imaging showed high signals in the right centrum ovale, and MR angiography revealed severe stenosis of the right intracranial ICA. Gadolinium-enhanced MR iMSDE imaging showed marked concentric enhancement in the vessel wall of the right stenosed ICA, which led to a definitive diagnosis of GCA via biopsy from the right superficial temporal artery. The patient's symptoms gradually improved after initiation of steroid treatment. Three months later, gadolinium-enhanced MR iMSDE imaging revealed improvement in the contrast enhancement in the vessel wall and vascular stenosis. CONCLUSION: Gadolinium-enhanced MR iMSDE imaging is useful to diagnose and evaluate GCA with intracranial vessel involvement.

Case Report: Paraneoplastic Tumefactive Demyelination Associated With Seminoma.

Paraneoplastic tumefactive demyelination (TD) is a rare disorder of the central nervous system that can be challenging to diagnose. Here, we describe a 32-year-old Japanese man with a TD associated with testicular seminoma. He presented with symptoms of right-sided motor and sensory impairment 2 days after vaccination for coronavirus disease 2019 (COVID-19). Brain magnetic resonance imaging (MRI) showed a high-intensity lesion in the left internal capsule. He had a 3-year history of enlargement of the left testicle. Blood examination showed tumor marker elevation and the presence of anti-amphiphysin antibodies. Whole-body computed tomography (CT) revealed mass lesions in the left testicle and enlargement of the retroperitoneal lymph nodes. Radical orchiectomy was performed. As the pathology showed testicular seminoma, chemotherapy was administered. After surgery, his neurological symptoms deteriorated. MRI revealed that the brain lesion had enlarged and progressed to a tumefactive lesion without gadolinium enhancement. The cerebrospinal fluid (CSF) examination was normal without pleocytosis or protein elevation. Steroid pulse therapy was added; however, his symptoms did not improve. A brain stereotactic biopsy was performed and the sample showed demyelinating lesions without malignant cells. As the initial corticosteroid therapy was ineffective, gamma globulin therapy was administered in parallel with chemotherapy, and the clinical symptoms and imaging findings were partially ameliorated. TD seldom appears as a paraneoplastic neurological syndrome. In addition, there are few reports of COVID-19 vaccination-associated demyelinating disease. Clinicians should recognize paraneoplastic TD, and the further accumulation of similar cases is needed.

Pathological findings of hypertrophic pachymeningitis associated with eosinophilic granulomatosis with polyangiitis.

The most common neurological manifestation of eosinophilic granulomatosis with polyangiitis (EGPA), formerly called Churg-Strauss syndrome, is mononeuritis multiplex caused by small-vessel vasculitis. In contrast, central nervous system involvement is rare. Among EGPA-associated central nervous system disorders, there are only a few reported cases of hypertrophic pachymeningitis (HP). Here, we report a patient with EGPA with headache and ophthalmoplegia who presented with HP and had a dural biopsy. The biopsy specimen showed lymphocytic inflammatory cell infiltration without EGPA-specific findings, that is, eosinophilic infiltration, granuloma or angiitis. To the best of our knowledge, there are no previous reports of EGPA-associated HP pathology. Here, we report the first case presentation of a patient with EGPA-associated HP with pathological findings.

Clearance of peripheral nerve misfolded mutant protein by infiltrated macrophages correlates with motor neuron disease progression.

Macrophages expressing C-C chemokine receptor type 2 (CCR2) infiltrate the central and peripheral neural tissues of amyotrophic lateral sclerosis (ALS) patients. To identify the functional role of CCR2+ macrophages in the pathomechanisms of ALS, we used an ALS animal model, mutant Cu/Zn superoxide dismutase 1G93A (mSOD1)-transgenic (Tg) mice. To clarify the CCR2 function in the model, we generated SOD1G93A/CCR2Red fluorescence protein (RFP)/Wild type (WT)/CX3CR1Green fluorescence protein (GFP)/WT-Tg mice, which heterozygously express CCR2-RFP and CX3CR1-GFP, and SOD1G93A/CCR2RFP/RFP-Tg mice, which lack CCR2 protein expression and present with a CCR2-deficient phenotype. In mSOD1-Tg mice, mSOD1 accumulated in the sciatic nerve earlier than in the spinal cord. Furthermore, spinal cords of SOD1G93A/CCR2RFP/WT/CX3CR1GFP/WT mice showed peripheral macrophage infiltration that emerged at the end-stage, whereas in peripheral nerves, macrophage infiltration started from the pre-symptomatic stage. Before disease onset, CCR2+ macrophages harboring mSOD1 infiltrated sciatic nerves earlier than the lumbar cord. CCR2-deficient mSOD1-Tg mice showed an earlier onset and axonal derangement in the sciatic nerve than CCR2-positive mSOD1-Tg mice. CCR2-deficient mSOD1-Tg mice showed an increase in deposited mSOD1 in the sciatic nerve compared with CCR2-positive mice. These findings suggest that CCR2+ and CX3CR1+ macrophages exert neuroprotective functions in mSOD1 ALS via mSOD1 clearance from the peripheral nerves.

[A case of brain tuberculoma resembling a malignant tumor].

A 35-year-old Sudanese man experienced bitter tastes on the right side of his tongue from January 2012. He was admitted to our hospital in March 2012 because of the appearance of distress, right facial palsy, nausea, and dizziness from late February 2012. A neurological examination revealed Bruns nystagmus, which increased on rightward gaze, as well as total hypoesthesia in the distribution of the maxillary branch of the right trigeminal nerve, moderate right peripheral type facial nerve palsy, and limb ataxia on the right side. Neither muscle weakness nor sensory disturbance was observed. Slight hyperreflexia was noted in the right extremities, and bilateral plantar responses were flexor. He showed wide-based ataxic gait and was unable to do tandem gait. Brain CT scans and magnetic resonance (MR) images revealed a mass lesion in the right pons to the right middle cerebellar peduncle with ring enhancement, suggestive of a "target" sign. Laboratory tests, including hematological and biochemical analyses, tumor markers, and antibodies, had normal values while the tuberculin reaction and QuantiFERON-TB Gold were strongly positive. Cerebrospinal fluid analysis revealed a slight increase in the protein level (76 mg/dl) with a normal cell count (2 per µl), and polymerase chain reaction-based tests and cultures were negative for Mycobacterium tuberculosis three times. Right subclavicular lymph node and right adrenal gland showed accumulation of fluorodeoxyglucose on positron emission tomography-CT, as did the mass lesion in the brainstem. These findings suggested a possibility of a metastatic malignant tumor or extrapleural tuberculoma. Because of the patient's religious belief, we were unable to perform a biopsy of the lymph node, and thus administered anti-tuberculous drugs. With treatment, his neurological symptoms such as facial palsy and ataxia improved steadily except for paradoxical worsening for the initial five days, and the gadolinium-enhanced lesion shrunk markedly. Follow-up MR images demonstrated that the lesions did not expand further for 9 months. From this course of treatment, we diagnosed the patient's tumor as brainstem tuberculoma. Brain tuberculoma sometimes resembles a malignant tumor, and it is therefore challenging to diagnose brainstem tuberculosis in cases without lung lesions. It is important to make a comprehensive diagnosis based on the patient's background, imaging, and course of treatment, and to treat brainstem tuberculoma promptly.

Mutations in MME cause an autosomal-recessive Charcot-Marie-Tooth disease type 2.

OBJECTIVE: The objective of this study was to identify new causes of Charcot-Marie-Tooth (CMT) disease in patients with autosomal-recessive (AR) CMT. METHODS: To efficiently identify novel causative genes for AR-CMT, we analyzed 303 unrelated Japanese patients with CMT using whole-exome sequencing and extracted recessive variants/genes shared among multiple patients. We performed mutation screening of the newly identified membrane metalloendopeptidase (MME) gene in 354 additional patients with CMT. We clinically, genetically, pathologically, and radiologically examined 10 patients with the MME mutation. RESULTS: We identified recessive mutations in MME in 10 patients. The MME gene encodes neprilysin (NEP), which is well known to be one of the most prominent beta-amyloid (Aß)-degrading enzymes. All patients had a similar phenotype consistent with late-onset axonal neuropathy. They showed muscle weakness, atrophy, and sensory disturbance in the lower extremities. All the MME mutations could be loss-of-function mutations, and we confirmed a lack/decrease of NEP protein expression in a peripheral nerve. No patients showed symptoms of dementia, and 1 patient showed no excess Aß in Pittsburgh compound-B positron emission tomography imaging. INTERPRETATION: Our results indicate that loss-of-function MME mutations are the most frequent cause of adult-onset AR-CMT2 in Japan, and we propose that this new disease should be termed AR-CMT2T. A loss-of-function MME mutation did not cause early-onset Alzheimer's disease. Identifying the MME mutation responsible for AR-CMT could improve the rate of molecular diagnosis and the understanding of the molecular mechanisms of CMT.

[A case of an anti-Ma2 antibody-positive patient presenting with variable CNS symptoms mimicking multiple system atrophy with a partial response to immunotherapy].

A 70-year-old man with a 5-month history of progressive bradykinesia of the bilateral lower extremities was admitted to our hospital. At the age of 64, he underwent proximal gastrectomy for gastric cancer. He also had a history of subacute combined degeneration of the spinal cord since the age of 67, which was successfully treated with vitamin B12 therapy. Four weeks before admission to our hospital, he admitted himself to his former hospital complaining of walking difficulty. Two weeks later, however, his symptoms progressed rapidly; he was immobilized for two weeks and did not respond to the vitamin therapy. On admission to our hospital, he showed moderate paralysis of the lower extremities, cog-wheel rigidity of the four extremities, and dystonic posture of his left hand. He also showed orthostatic hypotension and vesicorectal disorders. Blood examination and cerebrospinal fluid analysis revealed no remarkable abnormalities. Electroencephalography showed frontal dominant, high voltage, sharp waves. His brain and spinal MRI revealed no notable abnormalities. We suspected autoimmune disease and commenced one course of intravenous methylprednisolone therapy, resulting in improvement of the parkinsonism and orthostatic hypotension. Based on these results, we investigated possible neural antigens and detected anti-Ma2 antibody. In addition to limbic encephalitis, anti-Ma2 antibody-positive neural disorders are characterized by rapid eye movement sleep behavior disorders or parkinsonism. Here, we report an anti-Ma2 antibody positive patient presenting variable CNS symptoms mimicking multiple system atrophy, who responded to immunotherapy.

A case of synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome presenting with hypertrophic pachymeningitis.

A 43-year-old woman with a 3-year history of headache, fever, and swelling of the forehead, presented to our hospital. A general examination revealed palmar and plantar pustules. Blood analyses showed an elevated white blood cell count, C-reactive protein level, and erythrocyte sedimentation rate. Brain MRI revealed a partially thickened cranial bone with gadolinium enhancement, and also abnormally enhanced dura mater. Bone scintigraphy showed involvement of the cranial bone and bilateral sternoclavicular joints. Palmar skin biopsy indicated palmoplantar pustulosis. From these results, SAPHO (synovitis, acne, pustulosis, hyperostosis and osteitis) syndrome with associated hypertrophic pachymeningitis was diagnosed. After corticosteroid therapy and tonsillectomy, the clinical symptoms and radiological abnormalities were improved. Clinicians should be aware of SAPHO as a potential unusual cause of hypertrophic pachymeningitis.