Sistema glinfático: aspectos anatómicos, fisiológicos e implicaciones clínicas / Glymphatic system: Anatomo-physiological principles and their clinical implications

Introducción: El sistema glinfático comprende el conjunto de rutas perivasculares tanto arteriales como venosas que se encuentran en estrecha asociación con células astrogliales y que permiten la interacción entre el líquido cefalorraquídeo (LCR) y el líquido intersticial cerebral (LIC), para llevar a cabo procesos como la depuración de los metabolitos de desecho celular, o la distribución de nutrientes, así como contribuir al metabolismo cerebral local, la transmisión de volumen y la señalización paracrina cerebral. Contenidos: Este artículo busca profundizar en los conceptos anatómicos y fisiológicos, hasta el momento descritos, sobre este sistema macroscópico de transporte. Se realiza una búsqueda bibliográfica de revisiones y estudios experimentales sobre la anatomía, la fisiología y las implicaciones fisiopatológicas del sistema glinfático. Conclusiones: La identificación anatómica y funcional del sistema glinfático ha ampliado el conocimiento sobre la regulación del metabolismo cerebral en cuanto a distribución de nutrientes y cascadas de señalización celular. Al establecer una interacción entre el espacio subaracnoideo subyacente y el espacio intersticial cerebral, el sistema glinfático surge como uno de los mecanismos protagonistas de la homeostasis cerebral. La disfunción de esta vía hace parte de los mecanismos fisiopatológicos de múltiples trastornos neurológicos, ya sea por la acumulación de macromoléculas, como ocurre en la enfermedad de Alzheimer, o por la reducción del drenaje de sustancias químicas y citocinas proinflamatorias en patologías como la migraña o el trauma craneoencefálico.

Introduction: The glympathic system comprises the set of perivascular routes, arterials or venous, that are found in close relationship with astroglial cells and allow interaction between the cerebrospinal fluid (CSF) and the interstitial brain fluid (ISF), to carry processes like cell-wasting metabolites depuration, nutrients distribution, as well as make a contribution in the local brain metabolism, volumen transmition and brain paracrine signaling. Contents: This article seeks to deepen in the anatomical and physiological concepts, so far described, about this macroscopic transport system. A bibliographic search of reviews and experimental studies on the anatomy, physiology and pathophysiological implications of the glymphatic system is carried out. Conclusions: Anatomical and functional identification of glympathic system has broaden the knowledge about regulation of brain metabolism on the nutrients distribution and cell signaling cascades. When setting an interaction between the subarachnoid space and the brain interstitial space, the glymphatic system arise as one of the leading mechanisms of brain homeostasis. Disfunction of this pathway makes part of the patophysiological mechanisms of multiple neurological disease, either be by collection of macromolecules as in Alzheimer's disease, or by the reduction of inflammatory cytokines and chemical substances drainage as in migraine or traumatic brain injury (TBI).

Efficacy of electroacupuncture on acute intracerebral hemorrhage and its effect on serum AQP4 in patients / 中国针灸

OBJECTIVE@#To observe the effects on neural function, living ability and mental state of the patients with acute intracerebral hemorrhage (ICH), as well as aquaporin 4 (AQP4) in the serum after treated with electroacupuncture (EA) on the base of routine therapy of western medicine.@*METHODS@#Seventy-two acute ICH patients were randomized into an observation group (36 cases, 4 cases dropped off) and a control group (36 cases, 2 cases dropped off). In the control group, the conventional treatment was delivered such as stopping bleeding, preventing re-hemorrhage, controlling blood pressure, mitigating neural edema and reducing intracranial pressure. In the observation group, on the base of the treatment in the control group, EA was supplemented. Acupoints included Shuigou (GV 26), bilateral Neiguan (PC 6) and Sanyinjiao (SP 6) etc. Electric stimulation was operated at Neiguan (PC 6) and Sanyinjiao (SP 6) on the same side, with disperse-dense wave, and 2 Hz/100 Hz in frequency, tolerable current intensity. Electric stimulation was delivered for 30 min in each treatment, once daily and for 6 times per week. The duration of treatment was 2 weeks in the two groups. Before and after treatment, changes of the scores of National Institutes of Health stroke scale (NIHSS), modified Barthel index (MBI) and mini-mental state examination (MMSE), as well as AQP4 content in the serum were observed in the two groups; the efficacy and safety were compared between the two groups.@*RESULTS@#The NIHSS scores and the serum AQP4 content decreased after treatment when compared with those before treatment in the two groups (P<0.05), while, MBI and MMSE scores increased (P<0.05). In the observation group, NIHSS score and serum AQP4 content were lower than those of the control group (P<0.05), and MBI and MMSE scores were higher (P<0.05). The total effective rate of the observation group was 93.8% (30/32), higher than that of the control group (73.5%, 25/34, P<0.05). The treatment in the two groups was safe, without adverse reactions and events occurring in the patients.@*CONCLUSION@#Electroacupuncture, on the base of conventional treatment of western medicine, can effectively improve the neural function, living ability, mental state and serum AQP4 content of the patients with acute ICH. It is suggested that the effective treatment by electroacupuncture may be related to the regulation of the serum AQP4 content.

Analysis of the clinical characteristics and misdiagnosis of area postrema syndrome manifesting as intractable nausea, vomiting, and hiccups in neuromyelitis optica spectrum disorders / 中华内科杂志

Objective: To investigate the misdiagnosis of area postrema syndrome (APS) manifesting as intractable nausea, vomiting and hiccups in neuromyelitis optic spectrum disease (NMOSD) and reduce the risk of misdiagnosis. Methods: We retrospectively analyzed data from NMOSD patients attending the Department of Neurology at the First Medical Center of PLA General Hospital between January 2019 and July 2021. SPSS25.0 was then used to analyze the manifestations, misdiagnosis, and mistreatment of APS. Results: A total of 207 patients with NMOSD were included, including 21 males and 186 females. The mean age of onset was 39±15 years (range: 5-72 years). The proportion of patients who were positive for serum aquaporin 4 antibody was 82.6% (171/207). In total, 35.7% (74/207) of the NMOSD patients experienced APS during the disease course; of these patients, 70.3% (52/74) had APS as the first symptom and 29.7% (22/74) had APS as a secondary symptom. The misdiagnosis rates for these conditions were 90.4% (47/52) and 50.0% (11/22), respectively. As the first symptom, 19.2% (10/52) of patients during APS presented only with intractable nausea, vomiting and hiccups; 80.8% (42/52) of patients experienced other neurological symptoms. The Departments of Gastroenterology and General Medicine were the departments that most frequently made the first diagnosis of APS, accounting for 54.1% and 17.6% of patients, respectively. The most common misdiagnoses related to diseases of the digestive system and the median duration of misdiagnosis was 37 days. Conclusions: APS is a common symptom of NMOSD and is associated with a high rate of misdiagnosis. Other concomitant symptoms often occur with APS. Gaining an increased awareness of this disease/syndrome, obtaining a detailed patient history, and performing physical examinations are essential if we are to reduce and avoid misdiagnosis.

Baicalin treats cerebral ischemia reperfusion-induced brain edema in rats by inhibiting TRPV4 and AQP4 of astrocytes / 中国中药杂志

This study aims to explore the pharmacodynamic effect of baicalin on rat brain edema induced by cerebral ischemia reperfusion injury and discuss the mechanism from the perspective of inhibiting astrocyte swelling, which is expected to serve as a refe-rence for the treatment of cerebral ischemia with Chinese medicine. To be specific, middle cerebral artery occlusion(suture method) was used to induce cerebral ischemia in rats. Rats were randomized into normal group, model group, high-dose baicalin(20 mg·kg~(-1)) group, and low-dose baicalin(10 mg·kg~(-1)) group. The neurobehavior, brain index, brain water content, and cerebral infarction area of rats were measured 6 h and 24 h after cerebral ischemia. Brain slices were stained with hematoxylin and eosin(HE) for the observation of pathological morphology of cerebral cortex after baicalin treatment. Enzyme-linked immunosorbent assay(ELISA) was employed to determine the content of total L-glutathione(GSH) and glutamic acid(Glu) in brain tissue, Western blot to measure the content of glial fibrillary acidic protein(GFAP), aquaporin-4(AQP4), and transient receptor potential vanilloid type 4(TRPV4), and immunohistochemical staining to observe the expression of GFAP. The low-dose baicalin was used for exploring the mechanism. The experimental results showed that the neurobehavioral scores(6 h and 24 h of cerebral ischemia), brain water content, and cerebral infarction area of the model group were increased, and both high-dose and low-dose baicalin can lower the above three indexes. The content of GSH dropped but the content of Glu raised in brain tissue of rats in the model group. Low-dose baicalin can elevate the content of GSH and lower the content of Glu. According to the immunohistochemical staining result, the model group demonstrated the increase in GFAP expression, and swelling and proliferation of astrocytes, and the low-dose baicalin can significantly improve this situation. The results of Western blot showed that the expression of GFAP, TRPV4, and AQP4 in the cerebral cortex of the model group increased, and the low-dose baicalin reduce their expression. The cerebral cortex of rats in the model group was severely damaged, and the low-dose baicalin can significantly alleviate the damage. The above results indicate that baicalin can effectively relieve the brain edema caused by cerebral ischemia reperfusion injury in rats, possibly by suppressing astrocyte swelling and TRPV4 and AQP4.

Long-term safety of azathioprine for treatment of neuromyelitis optica spectrum disorders / Segurança a longo prazo da azatioprina no tratamento dos transtornos do espectro da neuromielite óptica

ABSTRACT Background: Azathioprine is a common first-line therapy for neuromyelitis optica spectrum disorder (NMOSD). Objective: The aim of this study was to determine whether long-term treatment (>10 years) with azathioprine is safe in NMOSD. Methods: We conducted a retrospective medical record review of all patients at the School of Medicine of the University of São Paulo (São Paulo, Brazil) who fulfilled the 2015 international consensus diagnostic criteria for NMOSD and were treated with azathioprine for at least 10 years. Results: Out of 375 patients assessed for eligibility, 19 were included in this analysis. These patients' median age was 44 years (range=28-61); they were mostly female (17/19) and AQP4-IgG seropositive (18/19). The median disease duration was 15 years (range=10-39) and most patients presented a relapsing clinical course (84.2%). The median duration of treatment was 11.9 years (range=10.0-23.8). The median annualized relapse rates (ARR) pre- and post-treatment with azathioprine were 1 (range=0.1-2) and 0.1 (range=0-0.35); p=0.09. Three patients (15.7%) had records of adverse events during the follow-up, which consisted of chronic B12 vitamin deficiency, pulmonary tuberculosis and breast cancer. Conclusion: Azathioprine may be considered a safe agent for long-term treatment (>10 years) of NMOSD, but continuous vigilance for infections and malignancies is required.

RESUMO Introdução: A azatioprina é um tratamento comum de primeira linha para os transtornos do espectro neuromielite óptica (NMOSD). Objetivo: Este estudo visou determinar a segurança do tratamento a longo prazo (>10 anos) da NMOSD com a azatioprina. Métodos: Foi realizada revisão retrospectiva de todos os prontuários de pacientes que preenchiam critérios de NMOSD de acordo com o "International Consensus Diagnostic Criteria for NMOSD" de 2015 em uso de azatioprina por ao menos 10 anos matriculados no ambulatório de Doenças Desmielinizantes do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. Resultados: De 375 pacientes avaliados, 19 preencheram critérios de inclusão para análise. A mediana de idade foi de 44 anos (variância=28-61); os pacientes eram predominantemente do sexo feminino (17/19) e AQP4-IgG soropositivos (18/19). A mediana do tempo de duração de doença foi 11,9 anos (variância=10,0-23,8), a mediana da taxa anualizada de surtos pré e pós-tratamento foi de 1 (variância=0,1-2) e 0,1 (variância=0-0,35), p=0,09. Três pacientes (15,7%) apresentaram registro de eventos adversos durante o seguimento: deficiência crônica de vitamina B12, tuberculose pulmonar e câncer de mama. Conclusão: A azatioprina provavelmente pode ser considerada segura para o tratamento a longo prazo (>10 anos) da NMOSD, porém vigilância contínua de neoplasias e infecções é necessária.

Different expressions of AQP1 and AQP4 in hyponatremic rat brain / Diferentes expresiones de AQP1 y AQP4 en cerebro de rata hiponatrémico

SUMMARY: The expression of aquaporin-1 (AQP1) in choroid plexus and aquaporin-4 (AQP4) in astrocyte of the hippocampal formation (HF) was studied in the rat to determine the role of AQP1 and AQP4 in the pathophysiology of systemic hyponatremia (SH). SH was induced by coadministration of dextrose solution intraperitoneally and through subcutaneous implantation of an osmotic minipump containing 8-deamino-arginin vasopressin (50ng/µl/h) for 24 and 48 h. Twenty- four and 48 h after the drug administration, there were significant reductions in Na+ concentration (111 ± 5 and 104 ± 2 mmol) and serum osmolarity (240 ± 13 and 221 ± 14 mOsm/L) as compared with control values (140 ± 4.7 mmol and 296 ± 5.2 mOsm/L), (p<0.01). The expression of AQP1 in the choroid plexus was increased three to five times from 24 h to 48 h after SH (329.86 ± 10.2 % and 531.5 ± 4.4 %, n=4, p<0.01). In contrast, AQP4 expression was significantly decreased up to 48 h after SH (36 ± 9 %, n=4, p<0.01). Quantitative immunoblotting revealed significant decreases of neuronal proteins in the HF after 24 to 48 h of SH. Therefore, we suggest that altered expression of AQP1 and AQP4 plays important role in the pathogenesis of systemic hyponatremia.

RESUMEN: En este análisis se estudió la expresión de acuaporina-1 (AQP1) en plexo coroideo y acuaporina-4 (AQP4) en astrocitos de la formación hipocampal (FH) en ratas para determinar el papel de AQP1 y AQP4 en la fisiopatología de la hiponatremia sistémica (HS). La HS fue inducida mediante la coadministración de solución de dextrosa por vía intraperitoneal y mediante la implantación subcutánea de una minibomba osmótica que contenía vasopresina 8-desaminoarginina (50 ng /µ l / h) durante 24 y 48 h. Veinticuatro y 48 h después de la administración del fármaco, hubo reducciones significativas en la concentración de Na + (111 ± 5 y 104 ± 2 mmol) y la osmolaridad sérica (240 ± 13 y 221 ± 14 mOsm /µL) en comparación con los valores de control (140 ± 4,7 mmol y 296 ± 5,2 mOsm / L), (p <0,01). La expresión de AQP1 en el plexo coroideo se incrementó de tres a cinco veces de 24 a 48 h después de HS (329,86 ± 10,2 % y 531,5 ± 4,4 %, n = 4, p <0,01). Por el contrario, la expresión de AQP4 se redujo significativamente hasta 48 h después de HS (36 ± 9 %, n = 4, p <0,01). La inmunotransferencia cuantitativa reveló disminuciones significativas de proteínas neuronales en el FH después de 24 a 48 h de SH. Por lo tanto, sugerimos que la expresión alterada de AQP1 y AQP4 juega un papel importante en la patogénesis de la hiponatremia sistémica.

Clinical Features of Neuromyelitis Optica Spectrum Disorders with Connective Tissue Diseases / 中国医学科学院学报

Objective To investigate the clinical features of neuromyelitis optica spectrum disorders(NMOSD)with connective tissue diseases(CTD). Methods Clinical data of 16 NMOSD-CTD patients and 54 NMOSD patients admitted to the Second Affiliated Hospital of Fujian Medical University from January 2015 to February 2020 were collected.The initial symptom,intracranial lesion,spinal cord lesion,laboratory examination and treatment response were compared between the two groups. Results The incidence of Sjögren's syndrome(SS)was the highest(10/16,62.5%)in NMOSD-CTD group.The NMOSD-CTD group had significantly higher positive rate of aquaporin-4 immunoglobulin G(AQP4-IgG)in serum or cerebrospinal fluid(100% vs. 70.2%,P=0.009),higher positive rates of serum anti-nuclear antibodies,anti Sjögren's syndrome A antibodies and anti-Ro52 autoantibodies(P0.05).Conclusions NMOSD is often complicated with CTD,and SS is the most common one.The positive rate of serum or cerebrospinal AQP4-IgG and the seropositivity of several other autoantibodies in NMOSD-CTD patients were higher than those in NMOSD patients.Neurological impairment in NMOSD-CTD patients were severer,which should arouse attention of clinicians.

Mielitis longitudinal extensa de presentación muy tardía: Una entidad del espectro de la neuromielitis óptica / Extensive longitudinal myelitis of very late presentation. An entity of the spectrum of optic neuromyelitis

Las enfermedades del espectro neuromielitis óptica son trastornos inflamatorios del sistema nervioso central caracterizados por una grave desmielinización y daño axonal inmunomediado que afecta principalmente a los nervios ópticos y médula espinal. Suelen presentars e en edades tempranas, aunque existen algunas comunicaciones en la literatura de pacientes con presentaciones tardías. Presentamos el caso de una mujer de 78 años que consultó por un cuadro de paraparesia grave, trastornos sensitivos y retención urinaria. Se realizó una resonancia magnética de columna cervicodorsal que evidenció una lesión medular longitudinal extensa. Se descartaron otras causas secundarias, basadas en la clínica y en resultados de laboratorio. El dosaje de anticuerpos anti-acuaporina 4 resultó positivo. Se indicó tratamiento con glucocorticoides a altas dosis y plasmaféresis, y mantenimiento con rituximab, obteniendo escasa respuesta clínica. En pacientes con lesiones medulares extensas se deben contemplar múltiples diagnósticos diferenciales según la presentación clínica, hallazgos mediante estudios por imágenes y epidemiología. Asimismo, debe incluir la búsqueda de anticuerpos anti-acuaporina 4 y contra la glicoproteína de la mielina del oligodendrocito, ya que el pronóstico funcional de estos pacientes suele ser desfavorable debido al gran componente destructivo de las lesiones. En consecuencia, el tratamiento temprano es fundamental a fin de limitar el daño agudo y prevenir futuras recaídas, lo cual es especialmente importante en presentaciones tardías de esta entidad debido a la escasa reserva funcional y baja capacidad de remielinización.

Optic neuromyelitis spectrum diseases are inflammatory disorders of the central nervous system characterized by severe demyelination and immunomediated axonal damage that mainly affects the optic nerves and spinal cord. They usually appear at an early age, although there are some reports in the literature of patients with late presentations. We present the case of a 78-year-old woman who consulted for severe paraparesis, sensory disorders, and urinary retention. An MRI of the cervicodorsal spine was performed, showing extensive longitudinal spinal injury. Secondary causes based on clinical observations and laboratory studies were ruled out. The dosage of anti-aquaporin 4 antibodies was positive. Acute treatment with high-dose glucocorticoids and plasmapheresis was indicated, and maintenance with rituximab, obtaining little clinical response. In patients with extensive spinal injuries, multiple differential diagnoses should be considered according to the clinical presentation, findings through imaging studies and epidemiology. Likewise, it should include the search for anti-aquaporin 4 antibodies and against the oligodendrocyte myelin glycoprotein, since the functional prognosis of these patients is usually unfavourable due to the large destructive component of the lesions. Consequently, early treatment is essential in order to limit acute damage and prevent future relapses, which is especially important in late presentations of this entity due to the low functional reserve and low remyelination capacity.

Effect of Schizonepetae Herba and Saposhnikoviae Radix on expression of AQP4 and AQP8 in colonic mucosa of rats with ulcerative colitis / 中国中药杂志

The aim of this paper was to investigate the effect of Schizonepetae Herba and Saposhnikoviae Radix(wind medicine) on the expression of AQP4 and AQP8 in colonic mucosa in rats with ulcerative colitis(UC). A total of 35 healthy SD male rats were randomly divided into normal group(gavaged with normal saline), DSS model group, as well as low, middle, and high dose wind medicine groups(Schizonepeta and Saposhnikovia 1∶1, gavaged at dosages of 6, 12, and 24 g·kg~(-1)·d~(-1)), with 7 in each group. UC rat model was established by free drinking of 3% dextran sulphate sodium(DSS) solution for 10 days. At the end of the 10 th day after the treatment, mice were put to death to collect colonic mucosa. The length of colon was measured; the colonic mucosal injury index(CMDI) and pathological changes of colon were observed. ELISA method was used for measuring the content of serum IL-1, IL-8, and immunohistochemical method was used to measure AQP4, AQP8 protein expressions in colon mucosa. The expressions of AQP4, AQP8 mRNA were measured by Real-time PCR. As compared with the normal group, the length of colon tissue was significantly reduced(P<0.01), CMDI scores and pathological scores were significantly increased(P<0.01), the levels of serum IL-1 and IL-8 were significantly increased(P<0.05) in model group; the immunohistochemical results showed that the protein expressions of AQP4, AQP8 were lower; the color was light yellow or brown; AQP4, AQP8 mRNA expressions in colon mucosa were significantly decreased in model group(P<0.01). CMDI scores, pathological scores, and the levels of serum IL-1, IL-8 in high, middle, low dose wind medicine groups were obvious lower than those in the model group(P<0.01 or P<0.05); the protein expressions of AQP4, AQP8 were higher; the color was chocolate brown or dark brown; the length of colon tissue, and the expressions of AQP4, AQP8 mRNA were obvious higher in wind medicine groups(P<0.01 or P<0.05). Schizonepetae Herba and Saposhnikoviae Radix could significantly improve the symptoms and histopathology of UC model rats and accelerate the intestinal mucosal healing. The mechanism may be related with up-regulating the expression level of AQP4 and AQP8 in colonic mucosa.

Decreased Aquaporin 4 and 6 mRNAs in Patients With Chronic Otitis Media With Otorrhea

OBJECTIVES: Aquaporins (AQPs) are integral membrane proteins engaged in the modulation of water homeostasis, but the roles they play in chronic otitis media (COM) have not been well investigated. Accordingly, we undertook document relations between the mRNA expressions of AQPs and COM, and explored the relation between these expressions and otorrhea, which is one of the most common symptoms of COM. METHODS: Levels of the mRNAs of AQP 1, 2, 3, 4, 5, 6, 8, and 10 were assayed by real-time polymerase chain reaction in inflammatory tissue samples from 81 patients with COM with or without otorrhea. Relationships between AQP mRNA levels and the presence or absence of otorrhea, the presence or absence of bacteria, hearing threshold levels, types of hearing loss, and clinical manifestations were also evaluated. RESULTS: AQP 1, 2, 3, 4, 5, 6, 8, and 10 mRNAs were expressed in inflammatory tissues obtained from all 81 patients with COM with or without otorrhea. AQP 5 mRNA was most expressed in, followed in descending order by AQP 3, 1, 10, 6, 8, 2, and 4. There were no significant intergroup differences in terms of age, sex, duration of illness, levels of hearing loss in both ears, or incidences of conductive or sensorineural hearing loss. However, AQP 4 (P=0.035) and 6 (P=0.085) mRNA levels were significantly lower in the otorrhea group. In addition, bacteria culture positivity (P=0.014) and the incidence of sensorineural hearing loss (P=0.020) were higher in the otorrhea group. CONCLUSION: AQP 1, 2, 3, 4, 5, 6, 8, and 10 are involved in the development of COM. Specifically, it shows reductions in AQP 4 and 6 mRNA levels, as observed in the otorrhea group, have an effect on the clinical manifestations of COM.

Persistent Malfunction of Glymphatic and Meningeal Lymphatic Drainage in a Mouse Model of Subarachnoid Hemorrhage

Subarachnoid hemorrhage (SAH) is a devastating cerebrovascular event that often is followed by permanent brain impairments. It is necessary to explore the pathogenesis of secondary pathological damages in order to find effective interventions for improving the prognosis of SAH. Blockage of brain lymphatic drainage has been shown to worsen cerebral ischemia and edema after acute SAH. However, whether or not there is persistent dysfunction of cerebral lymphatic drainage following SAH remains unclear. In this study, autologous blood was injected into the cisterna magna of mice to establish SAH model. One week after surgery, SAH mice showed decreases in fluorescent tracer drainage to the deep cervical lymph nodes (dcLNs) and influx into the brain parenchyma after injection into the cisterna magna. Moreover, SAH impaired polarization of astrocyte aquaporin-4 (AQP4) that is a functional marker of glymphatic clearance and resulted in accumulations of Tau proteins as well as CD3⁺, CD4⁺, and CD8⁺ cells in the brain. In addition, pathological changes, including microvascular spasm, activation of glial cells, neuroinflammation, and neuronal apoptosis were observed in the hippocampus of SAH mice. Present results demonstrate persistent malfunction of glymphatic and meningeal lymphatic drainage and related neuropathological damages after SAH. Targeting improvement of brain lymphatic clearance potentially serves as a new strategy for the treatment of SAH.

Mielitis parcial excéntrica como primera manifestación de trastornos del espectro de neuromyelitis óptica: presentación de casos y revisión de la literatura / Eccentric partial myelitis as the first manifestation of optic neuromyelitis spectrum disorders

RESUMEN El entendimiento de las caracteristicas clínicas del espectro de trastornos de Neuromielitis óptica (NMOSD) con mielitis parcial y neuritis óptica típica ha ampliado el diagnóstico en casos atípicos. Presentamos el caso de una mujer de 47 años que debuta con neuritis óptica atípica y mielitis parcial. Resonancia magnética cerebral y órbitas con realce de nervio óptico, quiasma óptico y tracto óptico derecho, de columna cervical y torácica contrastada con mielitis parcial a nivel C4 y T2. Fue tratada con bolos de metilprednisolona y plasmaferesis, con buena respuesta clínica. Se realizó anticuerpos aquaporina 4 sérico positivos.

SUMMARY The understanding of the clinical characteristics of the spectrum of optic neuromyelitis disorders (NMOSD) with partial myelitis and typical optic neuritis has extended the diagnosis in atypical cases. We present the case of a 47-year-old woman who debuts with atypical optic neuritis and partial myelitis. Magnetic resonance imaging and orbits with optic nerve enhancement, optical chiasm and right optic tract, cervical and thoracic spine contrasted with partial myelitis at level C4 and T2. I t was treated with boluses of Methylprednisolone and plasmapheresis, with good clinical response. Aquaporina 4 Serum positive antibodies were performed.

Enfermedades desmielinizantes / Demyelinating disorders

Las enfermedades desmielinizantes constituyen un grupo de afecciones de etiología autoinmune dirigida contra la mielina del sistema nervioso central. En muchos casos, el inicio del cuadro es precedido por una infección viral inespecífica. La esclerosis múltiple evoluciona con recaídas y remisiones con déficit neurológicos polifocales, siendo los más frecuentes la neuritis óptica, la mielitis transversa y el compromiso de tronco encefálico. Se caracteriza por lesiones hiperintensas que se observan en una resonancia magnética nuclear (RMN) en T2 y FLAIR peri-ventriculares y peri-callosas, cerebelo, tronco y médula espinal. La neuromielitis óptica se caracteriza por la presencia de neuritis óptica y mielitis transversa asociada a síndrome de área postrema y diencefálico. Las lesiones en RMN se distribuyen en los sectores ricos en acuaporina-4 (AQP-4): hipotálamo, peri tercer y cuarto ventrículo, nervios ópticos y médula espinal. Los anticuerpos anti AQP4 ayudan al diagnóstico aunque no son esenciales para el mismo. La encefalomielitis diseminada aguda es un cuadro clásicamente monofásico caracterizado por una encefalopatía aguda asociada a lesiones en RMN hiperintensas en T2 y FLAIR bilaterales, asimétricas, de gran tamaño y de bordes irregulares. En los tres casos, el líquido cefalorraquídeo (LCR) puede mostrar pleocitosis e hiperproteinorraquia. La presencia de bandas oligoclonales en LCR es característica de la esclerosis múltiple. En todos los casos, el tratamiento agudo incluye corticoides a altas dosis por vía endovenoso y en caso de no respuesta, plasmaféresis. Tanto la esclerosis múltiple como la neuromielitis óptica requieren tratamiento a largo plazo para evitar nuevas recaídas ya que se trata de enfermedades recurrentes.

Demyelinating diseases are a group of conditions of autoimmune etiology directed against the myelin of the central nervous system. In many cases, the onset of the illness is preceded by a nonspecific viral infection. Multiple sclerosis is a disease that evolves with relapses and remissions with polyfocal neurological deficits, being the most frequent optic neuritis, transverse myelitis and encephalic trunk involvement. Typically, magnetic resonance image (MRI) shows peri-ventricular, peri-callosal, cerebellum, brain stem and spinal cord hyperintensive lesions in T2 and FLAIR weighted images. Optic neuromyelitis is characterized by the presence of optic neuritis and transverse myelitis associated with the postrema and diencephalic area syndrome. MRI lesions are distributed in sectors rich with aquaporine-4 channels (AQP-4): hypothalamus, third and fourth ventricle, optic nerves and spinal cord. Finding anti AQP4 antibodies is useful for the diagnosis although they are not essential for it. Acute disseminated encephalomyelitis is typically a monophasic condition characterized by acute encephalopathy associated with hyperintense MRI large, bilateral and irregular asymmetric lesion in T2 and FLAIR weighted images. In all three cases, cerebral spine fluid (CSF) can show pleocytosis and hyperproteinorrachia. The presence of oligoclonal bands in CSF is characteristic of multiple sclerosis. In all cases, acute treatment includes high dose intravenous corticosteroids and plasmapheresis in non-responsive cases. Both multiple sclerosis and optic neuromyelitis require long-term treatment to prevent relapse and recurrent diseases.

Effects of aquaporin 4 and inward rectifier potassium channel 4 1 on medullospinal edema after methylprednisolone treatment to suppress acute spinal cord injury in rat

Abstract Purpose: To investigate the effects of aquaporin 4 (AQP4) and inward rectifier potassium channel 4.1 (Kir4.1) on medullospinal edema after treatment with methylprednisolone (MP) to suppress acute spinal cord injury (ASCI) in rats. Methods: Sprague Dawley rats were randomly divided into control, sham, ASCI, and MP-treated ASCI groups. After the induction of ASCI, we injected 30 mg/kg MP via the tail vein at various time points. The Tarlov scoring method was applied to evaluate neurological symptoms, and the wet-dry weights method was applied to measure the water content of the spinal cord. Results: The motor function score of the ASCI group was significantly lower than that of the sham group, and the spinal water content was significantly increased. In addition, the levels of AQP4 and Kir4.1 were significantly increased, as was their degree of coexpression. Compared with that in the ASCI group, the motor function score and the water content were significantly increased in the MP group; in addition, the expression and coexpression of AQP4 and Kir4.1 were significantly reduced. Conclusion: Methylprednisolone inhibited medullospinal edema in rats with acute spinal cord injury, possibly by reducing the coexpression of aquaporin 4 and Kir4.1 in medullospinal tissues.

Role of aquaporin-4 in the change of interstitial fluid drainage in Alzheimer's disease / 北京大学学报(医学版)

OBJECTIVE@#To observe the characteristics of the interstitial fluid (ISF) drainage in the Alzheimer's disease (AD) rats through magnetic resonance imaging (MRI) tracer gadolinium-diethylene triamine pentacetic acid (Gd-DTPA)spread in the brain extracellular space (ECS) and to discuss the role of aquaporin-4 (Aqp4) in the AD.@*METHODS@#Wild type SD rats (300-350 g) and Aqp4 gene knock out (Aqp4-/-) SD rats (300-350g) were divided into Sham group, AD group, Aqp4-/--Sham group and Aqp4-/--AD group. Sham group and Aqp4-/--Sham group were injected with saline by intraperitoneal each day for 6 weeks, and the AD group and Aqp4-/--AD group were injected with D-galactose by intraperitoneal each day for 6 weeks. MRI tracer Gd-DTPA (10 mmol/L, 2 μL) was injected into the hippocampus of the rats. MRI scan was performed at the end of 0.5 h, 1.5 h, 1 h, 2 h, and 3 h to observe the dynamic distribution of the Gd-DTPA in the hippocampus and the diffusion rate D*, clearance rate k' and half-life t1/2 measured.@*RESULTS@#The diffusion rate D* in Sham group was (2.66±0.36)×10-6 mm2/s, the diffusion rate D* in AD group was (2.72±0.62)×10-6 mm2/s, the diffusion rate D* in Aqp4-/--Sham group was (2.75±0.47)×10-6 mm2/s, the diffusion rate D* in Aqp4-/--AD group was (2.802±0.55)×10-6 mm2/s, and there was no statistically significant difference in the four groups (One-Way ANOVA, P>0.05).The clearance rate k' in Sham group was (4.57±0.14)×10-4/s, the clearance rate k' in AD group was (3.68±0.22)×10-4/s, the clearance rate k' in Aqp4-/--Sham group was (3.17±0.16)×10-4/s, the clearance rate k' in Aqp4-/--AD group was (2.59±0.19)×10-4/s, and there was significant difference in the four groups (One-Way ANOVA, P<0.05). The half-life t1/2 in Sham group was (0.67±0.12) h, the half-life t1/2 in AD group was (0.88±0.08) h, the half-life t1/2 in Aqp4-/--Sham group was (1.12±0.15) h, the half-life t1/2 in Aqp4-/--AD group was (1.58±0.11) h, and there was significance difference in the four groups(one-way ANOVA,P<0.05).@*CONCLUSION@#The ISF drainage is slow after AD and the loss of Aqp4 in the AD makes the ISF drainage obviously slow down, Aqp4 plays an important role in AD to remove the metabolism of waste out of the brain.

Recurrent Optic Neuritis as the Initial Symptom in Demyelinating Diseases

BACKGROUND AND PURPOSE: Optic neuritis (ON) is an inflammation of the optic nerve that can be recurrent, with unilateral or bilateral presentation. Diagnosing recurrent cases may be challenging. We aimed to compare patients with recurrent ON as their initial symptom according to their following final diagnoses: multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), or chronic relapsing inflammatory optic neuropathy (CRION). METHODS: The medical records of patients with initial recurrent ON who were followed at the Neuroimmunology Clinic of the Federal University of São Paulo between 2004 and 2016 were analyzed retrospectively. Patients were classified according to their final diagnosis into MS, NMOSD, or CRION, and the characteristics of these groups were compared to identify predictive factors. RESULTS: Thirty-three patients with recurrent ON were included, and 6, 14, and 13 had final diagnoses of MS, NMOSD, and CRION, respectively. Most of the patients were female with unilateral and severe ON in their first episode, and the initial Visual Functional System Score (VFSS) was ≥5 in 63.6%, 85.7%, and 16.7% of the patients with CRION, NMOSD, and MS, respectively. Anti-aquaporin-4 antibodies were detected in 9 of 21 (42.8%) tested patients. Seven of nine (77.8%) seropositive NMOSD patients experienced transverse myelitis episodes during the follow-up period. A multivariate regression analysis showed that the VFSS at the last medical appointment predicted the final diagnosis. CONCLUSIONS: A lower VFSS at the last medical appointment was predictive of MS. Patients with NMOSD and CRION have similar clinical characteristics, whereas NMOSD patients tend to have worse visual acuity.

An Anti-aquaporin 4 Positive Longitudinally Extensive Transverse Myelitis with Antecedent Necrotizing Pneumonia Associated with S. aureus

A 53-year-old male patient presented with quadriparesis during pulmonological hospitalization for the treatment of S. aureus associated necrotizing pneumonia. He was diagnosed with the aquaporin-4 (AQP4) positive longitudinally extensive transverse myelitis from pons to T3 level. Despite the administration of intravenous methylprednisolone and plasma exchange with appropriate antibiotics, the patient's neurological condition deteriorated and he died. Our case implies that an S. aureus associated necrotizing pneumonia can trigger an AQP4 positive neuromyelitis optica spectrum disorder and contribute to the devastating course.

A case of neuromyelitis optica spectrum disorders complicated with systemic lupus erythematosus and thymoma / 浙江大学学报·医学版

A 53-year-old male patient presented with hypopsia of his right eye for 2 months and lower extremities weakness for 8 days. Thoracic MRI demonstrated a lesion at T3 level appearing as hyperintense on T2-weighted images with non-enhancement by contrast medium and demyelinating lesion was considered. Aquaporin-4-Ab was positive and the antibody titer was 1:320 in serum. The diagnosis of neuromyelitis optica spectrum disorders was made. In addition, systemic lupus erythematosus and thymoma coexisted in this patient. After methylprednisolone impact treatment, plasma exchange and immunosuppressive therapy, the right vision and lower extremities weakness of the patient were improved.

Extremely dilution of strychnos Nux vomica mitigates alcohol-induced reduction in enthalpies associated with free water molecules in a fish brain

Introduction: Alcohol intoxication affects aquaporins in the glial cells of brain resulting in oedema. Nux vomica, a homeopathic drug of plant origin, is known to counteract alcohol effect. The objective of this present study is to find out the level of free water molecules in the brain of a teleost fish under ethanol intoxication. The second objective is to determine whether Nux vomica could restore the level of free water in the alcohol treated fish. Materials and methods: One group of fish was exposed to 456 mM ethanol for 30 min, another exposed first to a solution of Nux vomica 200c for 20 min and then to 456 mM ethanol for 30 min. The third group served as an untreated control. The mid brain of each fish was kept in an aluminium sample pan and its free water level was assessed by differential scanning calorimetry (DSC). Results: All alcohol treated fish showed significant reduction in the level of free water molecules as compared to the untreated control. Treatment with Nux vomica increased the level of free water in the brain significantly as compared to the untreated alcoholic group. Conclusion: Alcohol intoxication reduces free water molecules in the fish brain. Nux vom might have acted on aquaporins in the glial cells thereby increasing the level of free water in the brain. (AU)

Neuromyelitis optica: phenotypic characteristics in a Brazilian case series / Neuromielite óptica: características fenotípicas em uma série de casos brasileiros

ABSTRACT The definition of neuromyelitis optica (NMO) is still evolving. In 2015, the International Panel for NMO Diagnosis was convened to develop revised diagnostic criteria. There have been few studies on NMO in the Brazilian population. Objective To describe the characteristics of 34 Brazilian NMO patients. To evaluate the contribution of the 2015 criteria to the diagnosis of NMO spectrum disorders (NMOSD) in 40 patients with longitudinal extensive transverse myelitis (LEMT). Methods This is a retrospective, descriptive and analytic study. Results Among NMO patients, there was a predominance of women, with onset in the fourth decade of life, and AQP4-IgG seropositivity in 73.5%. The diagnosis of NMOSD was established in 37.5% of LETM patients according to AQP4-IgG positivity and in 5% of LETM patients if the AQP4-IgG result was unknown. Conclusions The characteristics of this series are similar to those of other Western populations. The AQP4-IgG testing assists in the diagnosis of NMOSD.

RESUMO Neuromielite óptica (NMO) é um conceito em evolução. Em 2015, o Painel Internacional para o diagnóstico de NMO apresentou novos critérios diagnósticos. Poucos são os estudos em NMO na população brasileira. Objetivos Descrever as características de 34 casos brasileiros de NMO. Avaliar a contribuição dos critérios de 2015 para o diagnóstico de desordens do espectro NMO em 40 pacientes com mielite transversa longitudinal extensa (MTLE). Métodos Estudo retrospectivo, descritivo e analítico. Resultados Predomínio do sexo feminino, início na quarta década e anticorpo anti-AQP4 positivo em 73,5% dos casos de NMO. Diagnóstico de desordem do espectro NMO estabelecido em 37.5% dos casos de MTLE com positividade do anticorpo anti-AQP4 e em 5% se o resultado sorológico fosse desconhecido. Conclusões Esta série de casos de NMO tem características semelhantes às de outras séries ocidentais. A pesquisa do anticorpo anti-AQP4 é relevante para o diagnóstico das desordens do espectro da NMO.