Contributing factors to quality of life after vertebral artery dissection: a prospective comparative study.

BACKGROUND: Vertebral artery dissection (VAD) may cause cerebral ischemia and impair quality of life (QOL) despite of good functional outcome. The aim of this study was the multimodal analysis of patient characteristics after VAD to identify contributing factors. METHODS: In an exploratory study, 34 consecutive patients with first-ever spontaneous VAD were prospectively examined in comparison to 38 patients with cerebral ischemia without dissection and 25 stroke mimics as control groups. Multimodal assessment was performed for clinical, neurological, cognitive, psychological and radiological data at baseline and for QOL, functional outcome, and stress symptoms by questionnaire at six months follow-up. Subgroup analysis stratified for QOL by Stroke Specific Quality of Life Scale (SS-QOL) were done for patients with good functional outcome (modified Ranking Scale (mRS) scoring 0-2). Predictors for QOL at follow-up were analyzed by regression model. RESULTS: 88.2% of patients with VAD suffered from acute cerebral ischemia. Thirteen of 32 VAD patients (40.6%) rated QOL at follow-up as bad (SS-QOL score ≤ 3.9) despite of good functional outcome (mRS score 0-2). Subgroup analysis yielded significantly higher scores for posttraumatic stress symptoms (p = 0.002) in this subgroup. Posttraumatic stress symptoms, severity of neurological disorders, and impaired neuropsychological baseline performance proved to be independent predictors for reduced QOL at follow-up according to regression analysis. CONCLUSION: VAD leads to impaired QOL at 6 months follow-up due to multiple factors. The data suggest that posttraumatic stress symptoms are of significant importance for the QOL after VAD. Clinical monitoring should address this topic to make timely treatment possible.

On the longevity of resident endoneurial macrophages in the peripheral nervous system: a study of physiological macrophage turnover in bone marrow chimeric mice.

Macrophages are intimately involved in the pathogenesis of peripheral nervous system (PNS) disorders. Recently, we characterized a resident endoneurial macrophage population, which contributes rapidly to the endoneurial macrophage response in PNS diseases. Unlike microglial cells, resident macrophages undergo a physiological turnover of 50% in the sciatic nerve and 80% in dorsal root ganglia (DRG) within 12 weeks. Further information about the dynamics of this turnover is not available. This study examined the macrophage turnover in the sciatic nerve and DRGs over a longer period and addresses the question whether the turnover of resident macrophages is complete or whether there is a truly resident endoneurial macrophage population. We used chimeric mice carrying GFP(+) bone marrow and immunohistochemistry to detect hematogenous (GFP(+)) endoneurial macrophages after turnover. Non-exchanged, resident macrophages were GFP(-). Quantification of GFP(+) and GFP(-) macrophages revealed a maximal turnover of 75%, reached in DRGs after 12 weeks and in sciatic nerves after 36 weeks. GFP(-) long-term resident macrophages were further characterized after sciatic nerve injury, where they participated in the early macrophage response of Wallerian degeneration. Our results point toward a small but truly resident PNS macrophage population. These macrophages are an interesting target for further characterization and might have a distinct role in peripheral nerve disease.

Further evidence for a crucial role of resident endoneurial macrophages in peripheral nerve disorders: lessons from acrylamide-induced neuropathy.

Endoneurial macrophages are crucially involved in the pathogenesis of neuropathies. Historically, the macrophage response in neuropathies is believed to be of hematogenous origin. However, recent studies could demonstrate an intrinsic generation of the early macrophage response by resident endoneurial macrophages after traumatic nerve injury and in a model of hereditary neuropathy. We hypothesized that the local macrophage response might suffice to generate an appropriate macrophage response in mild neuropathies, supplemented by infiltrating macrophages only in severe nerve pathology. To clarify this assumption, we investigated the macrophage response in acrylamide-induced neuropathy as a model of a slowly progressive neuropathy with a defined onset. We induced the neuropathy in bone marrow chimeric mice carrying green fluorescent protein transgenic bone marrow, allowing the differentiation of resident (GFP(-)) and invading hematogenous endoneurial (GFP(+)) macrophages. Quantification of GFP(-) and GFP(+) endoneurial macrophages in the sciatic nerve revealed an increase only of resident macrophages in proximal parts, whereas in distal parts a minor additional influx of hematogenous macrophages was observed. The immunohistochemical profile of GFP(-) and GFP(+) macrophages was similar but distal GFP(-) macrophages were differentially activated than their GFP(+) counterparts. Characterization of CCR2-deficient mice revealed a function for this chemokine system in attracting hematogenous macrophages but not in generating the intrinsic macrophage response. In conclusion, we provide evidence for a role of resident macrophages in acrylamide-induced neuropathy. Resident endoneurial macrophages intrinsically generate the macrophage response in this slowly progressive neuropathy, which only becomes supplemented by hematogenous macrophages in distal areas of more pronounced damage.

The ageing and myasthenic thymus: a morphometric study validating a standard procedure in the histological workup of thymic specimens.

The thymus is believed to play an important role in the pathogenesis of myasthenia gravis (MG). The 80% of MG patients with anti-acetylcholine receptor autoantibodies fall into three clinical subgroups: 1) thymoma; 2) early-onset MG (

Contribution of resident endoneurial macrophages to the local cellular response in experimental autoimmune neuritis.

Macrophages are intimately involved in the pathogenesis of inflammatory neuropathies. The contribution of resident endoneurial macrophages is unknown since their differentiation from infiltrating macrophages is difficult due to missing cellular markers. Previous studies demonstrated the participation of resident macrophages in Wallerian degeneration and the pathogenesis of hereditary neuropathies. The question arises whether resident macrophages are involved in experimental autoimmune neuritis (EAN) where they could contribute to immunosurveillance and antigen presentation. To address this question we used bone marrow chimeric rats, allowing the differentiation between resident and hematogenous cells. Immunohistochemistry and in situ hybridization were applied on to identify and characterize resident macrophages in terms of morphological features, expression of activation markers, proliferation, phagocytosis, and MHC-II expression. Endoneurial macrophages of resident origin were detectable at all stages of disease with a contribution of at least 27% of the total macrophages. They appeared activated by morphological and immunohistochemical criteria and proliferated early. MHC-II-positive resident macrophages were observed that had phagocytosed myelin. These results demonstrate that the macrophage response in EAN is partly of intrinsic origin. The rapid activation and proliferation of resident endoneurial macrophages points toward an active role of these cells in inflammatory peripheral nerve disease, especially early in disease.

Tumor recurrence and survival in patients treated for thymomas and thymic squamous cell carcinomas: a retrospective analysis.

PURPOSE: Thymic epithelial tumors (TET) are rare epithelial neoplasms of the thymus with considerable histologic heterogeneity. This retrospective study focused on the correlation of WHO-defined TET histotypes with survival and tumor recurrence in a large cohort of patients receiving different modes of treatment. PATIENTS AND METHODS: Two hundred twenty-eight patients were followed for up to 21 years (median, 60 months; range, 1 to 252 months) after primary surgery. Forty-two patients received adjuvant radiotherapy (mean dose, 53 Gy), and 33 patients received adjuvant chemotherapy. RESULTS: Seventy-six (88%) of 86 patients with WHO type A, AB, and B1 thymomas were treated by surgery alone, with three tumor relapses after 3 to 10 years (median, 3.4 years). Twelve of 67 patients with WHO type B2 and B3 thymomas in Masaoka stages I and II were treated by adjuvant radiotherapy without evidence of tumor recurrence after 1 to 12 years (median, 4 years). Among 75 patients with B2 and B3 thymomas with incomplete resection or a tumor stage III or higher, the recurrence rate was 34% (n = 23) after 0.5 to 17 years (median, 5 years) in patients receiving adjuvant radiochemotherapy, compared to 78% (seven of nine patients) in patients without adjuvant radiochemotherapy. Incomplete tumor resection was associated with a high recurrence rate (65%) and a poor prognosis (P <.01). CONCLUSION: The long-term outcome of TET patients is related to tumor stage, WHO histotype, completeness of surgical removal, and type of treatment. Prospective trials are warranted to formally address the efficacy of adjuvant therapy in the treatment of localized and advanced malignant TETs.

A novel Twinkle gene mutation in autosomal dominant progressive external ophthalmoplegia.

Autosomal dominant progressive external ophthalmoplegia is a common neurological presentation of mitochondrial disease and is characterised by multiple deletions of mitochondrial DNA in muscle. We describe a family with autosomal dominant progressive external ophthalmoplegia caused by a novel heterozygous A to C transversion at nucleotide 956 of the Twinkle gene. The deltoid muscle biopsy of the index case revealed sparse respiratory deficient cells. Multiple mitochondrial DNA deletions were clearly evident in the index case by both long-range and real-time polymerase chain reaction assays but not by Southern blotting, highlighting the diagnostic difficulties associated with characterising patients with multiple mitochondrial DNA deletions.

Autoimmunity in the peripheral nervous system.

Autoimmune disorders of the peripheral nervous system (PNS) comprise a heterogeneous group of diseases that result from an aberrant immune response. Most of these disorders present severe morbidity and, in some cases, mortality. Even those conditions that are self-limited may display severe disability and necessitate hospitalization. Although their etiology remains elusive, there is increasing knowledge of the pathophysiological mechanisms causing tissue dysfunction and structural damage. The discovery of several mediators that constitute the molecular mechanisms of cell-cell and cell-extracellular-matrix interactions has revealed insight into various aspects of the neuroimmune interaction. Classic animal models associated with new genetic approaches have further increased our comprehension of the molecular pathways that regulate inflammatory disorders of the nervous system. The aim of this review is to describe various types and functions of the principal molecular components of the neuroimmune interaction and their importance in the principal autoimmune disorders of the PNS. We also provide an extensive description of clinical and pathological features of autoimmune disorders of the PNS, along with diagnostic and therapeutic implications.

Side effects of intravenous immunoglobulins in neurological autoimmune disorders--a prospective study.

The increased use of intravenous immunoglobulins (IVIg) in the treatment of neurological autoimmune diseases has led to more awareness of adverse reactions. We studied prospectively the side effects of IVIg during 84 treatment courses with a total of 341 infusions under routine clinical conditions. Mild reactions were common. Headache was noted most often, occurring during 30% of treatment courses. There were three severe adverse events (3.6% of all treatment courses) that led to discontinuation of the treatment, namely thrombosis of the jugular vein, allergic reaction and retrosternal pressure. Significant changes in laboratory findings were seen for leucocytes, erythrocytes, haematocrit, haemoglobin, ALAT and ASAT. None of these changes were clinically relevant. The elevation of liver enzymes was dependent on the IVIg preparation used, while there was no association with the underlying disease, age, or gender of the patient. In conclusion, this prospective study confirms the high frequency of mild, self-limited side effects of IVIg. Elevation of liver enzymes may possibly be associated with certain IVIg preparations. Bearing these complications in mind, this prospective study supports the notion that IVIg can generally be regarded as safe, leading to severe adverse events during only 3 (0.9%) of 341 infusions (or 3 of 84 treatment courses, 3.6 %). However, careful monitoring for severe side effects remains mandatory, and we propose that laboratory findings like full blood count, renal and liver function should be monitored routinely.

Health-related quality of life in ALS, myasthenia gravis and facioscapulohumeral muscular dystrophy.

Neuromuscular disorders are rare diseases with a chronic and debilitating course. Unfortunately, data on the health-related quality of life (HRQoL) in neuromuscular diseases are limited. The objective of this multicentre cross-sectional study was to compare the HRQoL in patients with amyotrophic lateral sclerosis (ALS), facioscapulohumeral muscular dystrophy (FSHD) and myasthenia gravis (MG) and to identify the determinants of the HRQoL in these diseases. We recruited 91 consecutive outpatients with ALS (n = 37), FSHD (n = 17) or MG (n = 37) in seven specialized German health centres. The HRQoL was determined using the 36-Item Short Form Health Survey (SF-36) and the EuroQol (EQ-5D). Independent predictors of the HRQoL were identified using multiple regression analysis. The HRQoL in all domains of the SF-36, except for bodily pain, was significantly reduced. The domains related to physical health (physical functioning, physical role) were most affected. The EQ-5D-index score was most reduced in ALS (0.54) and least reduced in MG (0.89). Independent predictors of a reduced HRQoL were disease severity and depression in ALS, and disease severity, depression, older age and increased body-mass index in MG. The patterns of HRQoL-impairment in neuromuscular disorders share some common features, such as a more pronounced reduction in the HRQoL related to physical health, but there are a number of disease-specific features that should be considered in outcomes of clinical trials and treatment guidelines. In addition to the treatment of motor symptoms, greater attention should be paid to the treatment of depression, which was found to be among the independent predictors of the HRQoL in ALS and MG.

Socioeconomic burden of amyotrophic lateral sclerosis, myasthenia gravis and facioscapulohumeral muscular dystrophy.

Neuromuscular disorders (NMD) are chronic devastating diseases. The aim of this multicenter cross-sectional study was to evaluate the socioeconomic impact of three NMDs in Germany. Patients (n = 107) with amyotrophic lateral sclerosis (ALS), myasthenia gravis (MG) or facioscapulohumeral muscular dystrophy (FSHD) were recruited consecutively in seven centers in Germany. The health-economic data were collected using a "bottom-up" approach consisting of comprehensive questionnaires and patient diaries. Costs were evaluated from the societal perspective in 2009 Euros (EUR). Total annual costs from the societal perspective were EUR 36,380 (95% CI 27,090-47,970) per patient in ALS, EUR 26,240 (95% CI 17,770-37,940) in FSHD and EUR 14,950 (95% CI 10,470-21,730) in MG. The main components of costs were the expenditures of health insurance and the loss of productivity of patients and their caregivers. The following independent cost-driving factors were identified: disease severity, assistance in activities of daily living (ADL), dementia and younger age in ALS, disease severity in FSHD and assistance in ADL, disease severity and assistance in ADL in MG. The socioeconomic burden of NMDs in Germany is considerable. Further studies evaluating both the health-economic and clinical effects of NMD treatment as well as disease management programs and benchmarking activities are necessary.

The role of CC chemokine receptor 2 on microglia activation and blood-borne cell recruitment after transient focal cerebral ischemia in mice.

The chemokine receptor 2 (CCR2) is involved in inflammatory reactions following cerebral ischemia. Monocyte chemoattractant protein-1 (MCP-1) binds with high affinity to CCR2. MCP-1 is necessary for recruiting blood-borne cells to the injury site whereas it does not affect microglia activation and migration. MCP-1-deficient mice develop smaller infarcts and show a better functional outcome. CCR2-deficient mice also develop smaller infarcts and have a reduced expression of inflammatory cytokines during reperfusion. In the present study we investigated the differential role of inflammatory cells in CCR2-deficient mice, using green fluorescent protein (GFP)-transgenic bone marrow chimeras. After 30 min of transient middle cerebral artery occlusion (MCAO), activation of local microglia was similar in CCR2-deficient animals and their littermate controls over the study period, whereas an influx of GFP-positive cells was diminished in CCR2-deficient mice. Infiltrating macrophages were significantly reduced at day seven in the deficient animals (26.04+/-25.19 cells/mm(2)) compared to control mice (86.83+/-44.41 cells/mm(2), p<0.001). Neutrophils were also significantly reduced in CCR2-deficient mice (83% on day 2, 76% on day 4 and 89% on day 7, p<0.001). A significant reduction of infarct volume in CCR2-deficient animals could not be detected. In this study a clear differentiation of local and blood-borne inflammatory cell reaction after cerebral ischemia could be shown, demonstrating that CCR2-deficiency attenuates hematogenous cell recruitment to the injury site whereas microglia activation and migration is not affected.

Turn-over of meningeal and perivascular macrophages in the brain of MCP-1-, CCR-2- or double knockout mice.

Perivascular and meningeal macrophages are important for immune surveillance in the healthy and the injured brain. Monocyte chemoattractant protein-1 (MCP-1) regulates macrophage migration and permeability of the blood brain barrier. In the present study, we investigated the influence of MCP-1 or/and chemokine receptor 2 (CCR2)-deficiency on macrophage turnover. The results showed no influence of single MCP-1- or CCR-2-deficiency, but double-deficient mice revealed a virtual absence of blood-borne macrophage recruitment. This finding emphasizes that the MCP-1/CCR2 axis is crucially important for macrophage turnover and compensatory mechanisms remain only partially sufficient to sustain regulatory functions.

Macrophage colony stimulating factor is a crucial factor for the intrinsic macrophage response in mice heterozygously deficient for the myelin protein P0.

Mouse mutants heterozygously deficient for the myelin protein P0 (P0+/-) resemble certain forms of human hereditary neuropathies. Endoneurial macrophages of intrinsic origin are intimately involved in the pathogenesis of the demyelinating neuropathy in these mutants. We have previously shown that deficiency for macrophage colony stimulating factor (M-CSF) prevents an increase of the number of endoneurial macrophages and alleviates the mutants' demyelinating phenotype. The aim of this study was to investigate which population of endoneurial macrophages - long-term resident macrophages or recently infiltrated macrophages - is affected by M-CSF deficiency. For this purpose, we generated bone marrow chimeric mice by transplanting GFP+ bone marrow into P0 mutants (P0+/-) and P0 mutants that lack M-CSF (P0+/- mcsf-op). This enabled us to discriminate recently infiltrated short-term resident GFP+ macrophages from long-term resident GFP- macrophages. Three months after bone marrow transplantation, P0+/- mice expressing M-CSF showed a substantial upregulation and activation of both GFP- and GFP+ macrophages in femoral nerves when compared to P0+/+ mice. In contrast, in P0+/- mcsf-op mutants, both GFP- and GFP+ macrophages did not substantially increase. Only small numbers of GFP+ but no GFP- macrophages were activated and phagocytosed myelin in chimeric P0+/- mcsf-op mutants, possibly reflecting recent activation outside the endoneurium before entering the nerve. Our findings demonstrate that M-CSF is crucial for the activation, in situ increase and myelin phagocytosis of both long-term and short-term resident endoneurial macrophages in P0+/- myelin mutants. M-CSF is, therefore, considered as a target candidate for therapeutic strategies to treat human demyelinating neuropathies.

Predominant phagocytic activity of resident microglia over hematogenous macrophages following transient focal cerebral ischemia: an investigation using green fluorescent protein transgenic bone marrow chimeric mice.

Activated microglia and hematogenous macrophages are known to be involved in infarct development after cerebral ischemia. Traditionally, hematogenic macrophages are thought to be the primary cells to remove the ischemic cell debris. However, phagocytosis is a well known property also of activated microglia. Due to a lack of discriminating cellular markers, the cellular origin of phagocytes and the temporal course of phagocytosis by these two cell types are largely unknown. In this study, we used green fluorescent protein (GFP) transgenic bone marrow chimeric mice and semithin serial sections after methyl methacrylate embedding of the brains to dissect in detail the proportion of identified activated resident microglial cells and infiltrating hematogenous macrophages in phagocytosing neuronal cell debris after 30 min of transient focal cerebral ischemia. Already at day one after reperfusion, we found a rapid decrease of neurons in the ischemic tissue reaching minimum numbers at day seven. Resident GFP-negative microglial cells rapidly became activated at day one and started to phagocytose neuronal material. By contrast, hematogenous macrophages incorporating neuronal cell debris were observed in the ischemic area not earlier than on day four. Quantitative analysis showed maximum numbers of phagocytes of local origin within 2 days and of blood-borne macrophages on day four. The majority of phagocytes in the infarct area were derived from local microglia, preceding and predominating over phagocytes of hematogenous origin. This recruitment reveals a remarkable predominance of local defense mechanisms for tissue clearance over immune cells arriving from the blood after ischemic damage.

Neuroprotective effect of the immune system in a mouse model of severe dysmyelinating hereditary neuropathy: enhanced axonal degeneration following disruption of the RAG-1 gene.

In mouse models of later onset forms of human hereditary demyelinating neuropathies, the immune system plays a crucial pathogenic role. Here, we investigated the influence of immune cells on early onset dysmyelination in mice homozygously deficient of the myelin component P0. In peripheral nerves of P0(-/-) mice, CD8+ T-lymphocytes increased with age. Macrophages peaked at 3 months followed by a substantial decline. They were mainly of hematogenous origin. To evaluate the functional role of immune cells, we cross-bred P0(-/-) mutants with RAG-1-deficient mice. At 3 months, the number of endoneurial macrophages did not differ from the macrophage number of immunocompetent myelin mutants, but the later decline of macrophages was not observed. Quantitative electron microscopy revealed that in plantar nerves of 6-month-old double mutants, significantly more axons had degenerated than in immunocompetent littermates. These data suggest a neuroprotective net effect of T-lymphocytes on axon survival in inherited, early onset dysmyelination.

A CTLA4high genotype is associated with myasthenia gravis in thymoma patients.

Myasthenia gravis (MG) in thymoma patients depends critically on intratumorous generation and export of mature autoreactive CD4+ T cells. Why non-MG thymomas fail to produce CD4+ T cells is unknown. We studied three single-nucleotide polymorphisms of the cytotoxic T-lymphocyte-associated antigen 4(CTLA4) gene in thymoma patients, nonthymoma early-onset MG patients, and control subjects. Surprisingly, the CTLA4high genotype +49A/A, which is protective against several autoimmune diseases, exerted a prominent predisposing effect to paraneoplastic MG in thymoma patients. The unusual disease association with a CTLA4high genotype implies a unique pathogenesis of paraneoplastic MG, with high CTLA4 levels possibly supporting the nontolerogenic selection of CD4+ T cells in MG-associated thymomas.

Microglial activation precedes and predominates over macrophage infiltration in transient focal cerebral ischemia: a study in green fluorescent protein transgenic bone marrow chimeric mice.

Resident microglia and hematogenous macrophages play crucial roles in the pathogenetic cascade following cerebral ischemia but may functionally differ regarding neuroprotective and cytotoxic properties. Distinction between these cells has not been possible due to a lack of discriminating cellular markers. We generated bone marrow chimeric mice by transplanting bone marrow from green fluorescent protein (GFP) transgenic mice into irradiated wild-type recipients. Transient focal cerebral ischemia was induced by transient middle cerebral artery occlusion (MCAO) for 30 min. Resident microglia and infiltrating macrophages were identified by immunohistochemistry and GFP fluorescence after 1-28 days. The first blood-derived cells infiltrating the infarct area were seen on Day 1 and identified as granulocytes. Hematogenous GFP(+) macrophages were rarely observed on Day 2, reached peak numbers on Day 7, and decreased thereafter. In contrast, resident GFP(-) microglial cells rapidly became activated already on Day 1 after MCAO. Even on Days 4 and 7, most macrophage-like cells remained GFP(-), indicating their derivation from resident microglia. Hematogenous macrophages were able to acquire a ramified morphology indistinguishable from resident microglia while microglial cells could develop into a phagocytic phenotype indistinguishable from infiltrating macrophages. The vast majority of macrophages in the infarct area are derived from local microglia, revealing a remarkable predominance of local defense mechanisms over immune cells arriving from the blood. GFP bone marrow chimeric mice are a powerful tool to further differentiate the function of resident microglia and hematogenous macrophages following cerebral ischemia.

Origin of pathogenic macrophages and endoneurial fibroblast-like cells in an animal model of inherited neuropathy.

Macrophages have recently been shown to be critically involved in the pathogenesis of genetically determined demyelination in mice heterozygously deficient for P0 (P0(+-)). Since little is known about the origin of these cells, we created chimeric P0(+-) mice by transplanting bone marrow from green fluorescent protein (GFP)-transgenic mice into irradiated P0(+-) mice. When analyzing chimeric P0(+-) mice, we could determine two populations (GFP(+) and GFP(-)) of endoneurial macrophages that became phagocytic for myelin and increased in number. We found that both GFP(-) resident macrophages and GFP(+) macrophages proliferated in peripheral nerves of P0(+-) mice but not in nerves of chimeric or nonchimeric P0(++) mice. These findings demonstrate a so far poorly recognized role of resident endoneurial macrophages in demyelinating neuropathies. Surprisingly, we also found GFP(+) cells that unequivocally showed the morphological characteristics of fibroblasts. These blood-borne fibroblast-like cells express the common hematopoetic stem cell marker CD34 and might comprise another cell type of potential importance for immune regulation in hereditary demyelinating neuropathies.