Polirradiculoneuropatía desmielinizante inflamatoria crónica con anticuerpos antineurofascina-155: primer reporte de caso en Perú / Chronic inflammatory demyelinating polyradiculoneuropathy with antineurofascin-155 antibodies: A first case report in Peru

La polirradiculoneuropatía desmielinizante inflamatoria crónica, es un grupo de neuro-patías periféricas inmunomediadas clínicamente heterogéneas que comparten manifes-taciones neurofisiológicas de desmielinización y disociación albuminocitológica. Se distinguen una forma típica y variantes atípicas, algunas asociadas a anticuerpos con-tra proteínas del nodo de Ranvier, como la neurofascina- 155. Presentamos el caso de un varón de 38 años, que acudió por cuadro de ocho meses de evolución, caracterizado por parestesias y debilidad progresiva de cuatro extremidades, asociado a diplopía y disfagia. El paciente estaba despierto, con cuadriparesia flácida simétrica de predominio distal, hipotrofia en dorso y palma de ambas manos, arreflexia generalizada, temblor postural de baja frecuencia y alta amplitud en miembros superiores de predominio izquierdo, dismetría apendicular, adiadococinesia, oftalmoparesia a la dextroversión en ojo dere-cho, reflejo nauseoso ausente, marcha atáxica con aumento de base de sustentación y signo de Romberg positivo. El líquido cefalorraquideo mostró disociación albuminocitológica y la electromiografía fue compatible con polineuropatía sensitivo- motora primariamente desmielinizante. Por la sospecha clínica, solicitamos anticuerpos antineurofascina- 155, que resultaron positivos. Recibió tratamiento con metilprednisolona a dosis de un gramo al día durante cinco días, seguido de un miligramo por kilogramo durante tres meses de prednisona, con disminución progresiva con lo que mejoró la diplopía y la disfagia, sin mejoría de la fuerza en extremidades e incluso empeoramiento de la funcionabilidad. Por esta razón se inició tratamiento con rituximab en dosis de dos gramos presentando una notable mejoría en la fuerza muscular distal, el temblor, la estabilidad de la marcha, coordinación y de su funcionabilidad medida con la escala de Rankin modificado.

Chronic inflammatory demyelinating polyradiculoneuropathy is a clinically heterogeneous group of immune- mediated peripheral neuropathies that share neurophysiological manifesta-tions of demyelination and albuminocytologic dissociation. There are typical and atypical variants of this disease, some associated with antibodies against proteins of the node of Ranvier, such as neurofascin- 155. We present the case of a 38- year- old male who presented with an eight- month history of par-esthesia and progressive weakness of four limbs associated with diplopia and dysphagia. The patient was conscious, with symmetric flaccid quadriparesis of distal predominance, hyp-otrophy in the dorsum and palm of both hands, generalized areflexia, postural low frequency, and high amplitude tremor in upper limbs of left predominance, appendicular dysmetria, dys-diadochokinesia, ophthalmoparesis to dextroversion in the right eye, absent gag reflex, ataxic gait with an increased base of support and positive Romberg's sign. Cerebrospinal fluid showed albuminocytologic dissociation, and electromyography was com-patible with primarily demyelinating sensory- motor polyneuropathy. Due to clinical suspicion, we requested anti- neurofascin- 155 antibodies, which tested positive. The patient was treated with methylprednisolone at a dose of one gram per day for five days, followed by one milligram per kilogram for three months of prednisone, with progressive de-crease, which improved diplopia and dysphagia, with no effect on limb strength and even worsening of function. For this reason, treatment with rituximab was started in doses of two grams, presenting a substantial improvement in distal muscle strength, tremor, gait stability, coordination, and functionality measured with the modified Rankin scale.

A case report of a successful multidisciplinary management of an abdominal pregnancy / Manejo multidisciplinario exitoso del embarazo abdominal. Reporte de un caso peruano

Abdominal pregnancy is defined as one that occurs outside of the uterus and fallopian tubes in the abdominal cavity. We present the case of a 30-year-old Peruvian female patient from Lima with a surgical history of exploratory laparotomy due to tubal ectopic pregnancy and appendectomy without further relevant personal or family histories. She attended the emergency room of a social security hospital in Peru with a referral from a district hospital and a diagnosis of abdominal pregnancy at 14 weeks of gestational age without previous prenatal controls. Symptomatology at hospital admission was colic-type abdominal pain in the hypogastrium without vaginal bleeding, fluid loss or fever. During hospitalization, she underwent an exploratory laparotomy with embolization of the uterine artery, left salpingectomy, and removal of the abdominal ectopic pregnancy. The evolution was favorable after the surgery, and she was discharged. Without further complications, she continues her controls at the obstetrics and gynecology outpatient service without complications.

El embarazo abdominal es aquel embarazo que ocurre fuera del útero y las trompas de Falopio en la cavidad abdominal. Presentamos el caso de una paciente peruana de 30 años proveniente de la ciudad de Lima, con antecedentes quirúrgicos de laparotomía exploradora por embarazo ectópico tubárico y apendicectomía, sin otras patologías ni antecedentes familiares de importancia. La paciente acude al servicio de urgencias de un hospital del seguro social en Perú derivada de un hospital distrital con diagnóstico de embarazo abdominal a las 14 semanas de edad gestacional, sin controles prenatales previos. La sintomatología al ingreso hospitalario fue dolor abdominal de tipo cólico a nivel del hipogastrio, sin sangrado vaginal, pérdida de líquidos o fiebre. Durante su hospitalización se le realizó una laparotomía exploratoria con embolización de la arteria uterina, salpingectomía izquierda y extracción del embarazo abdominal. La evolución fue favorable tras la intervención quirúrgica, siendo dada de alta. Actualmente continúa sus controles en el servicio de consulta externa del servicio de ginecología y obstetricia sin complicaciones.

Combined central and peripheral demyelination after varicella-zoster virus infection: a case report / 中华神经科杂志

Combined central and peripheral demyelination (CCPD) is a rare autoimmune disease and its action mechanism remains unknown. This article described a case of CCPD with anti-neurofascin 155 IgG4 antibodies after varicella-zoster virus (VZV) infection who was recovered after steroids and intravenous immunoglobulin treatments. The clinical characteristics of this patient were summarized and the possible pathogenesis was discussed, so as to provide information of CCPD after VZV infection for clinicians.

Anti-neurofascin 186 antibody associated acute immune sensory polyradiculopathy: a case report and review of literature / 中华神经科杂志

Objective:To describe the clinical features of a patient of anti-neurofascin 186 (NF186) antibody associated acute immune sensory polyradiculopathy (AISP), and enhance understanding of AISP/chronic immune sensory polyradiculopathy (CISP).Methods:The clinical characteristics, diagnosis and treatment of a domestic AISP patient with NF186 antibody positive admitted to the First Hospital of Shanxi Medical University in December 2021 were summarized, and the previously reported cases of AISP/CISP were systematically reviewed.Results:The patient was a 62-year-old male with acute onset. The clinical manifestations included severe sensory ataxia, increased protein in cerebrospinal fluid, no response to stimulation of the central segment of somatosensory evoked potentials (SEP), normal sensory and motor nerve conduction, and positive serum anti-NF186 antibody (1∶32). After glucocorticoid treatment, the clinical symptoms and SEP were significantly improved. The drug was stopped for 2 months, and there was no recurrence. There were 23 cases of AISP and CISP with complete data reported in the literature (including this patient). The age of onset was (54.7±17.7) years, and the ratio of male to female was 1.88. Three patients with acute onset were classified as AISP. A total of 95.7% (22/23) of patients showed sensory ataxia without limb weakness, 95.0% (19/20) of patients showed prolonged cortical potential latency or even no response, and 95.5% (21/22) of patients showed increased cerebrospinal fluid protein in varying degrees, and nerve root thickening or abnormal enhancement was not common. All 10 patients receiving immunotherapy responded to corticosteroids or intravenous immune globulin. Only 6 AISP/CISP articles reported screening for anti-ganglioside antibodies or Ranvier′s node-paranodal region-related antibodies, and no positive NF186 antibodies were reported. All the 3 patients with AISP had some characteristics of CISP/chronic inflammatory demyelinating polyradiculoneuropathy, and there was no significant difference between AISP and CISP patients in clinical features except the mode of onset.Conclusions:NF186 antibody could cause AISP, which presents as acute onset sensory ataxia. AISP is responsive to glucocorticoid therapy. Except for the mode of onset, AISP and CISP are difficult to distinguish from clinical, electrophysiological, pathological aspects and pathogenic antibodies, so they may be two different manifestations of the same disease.

The electrophysiological features of patients with anti-neurofascin 155 IgG4 antibodies positive chronic inflammatory demyelinating polyradiculoneuropathy / 中华神经科杂志

Objective:To investigate the electrophysiological features of patients with anti-neurofascin 155 (NF155) IgG4 antibodies positive chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).Methods:The electrophysiological data of 6 anti-NF155 IgG4 antibodies positive CIDP patients in Beijing Tiantan Hospital, Capital Medical University from September 2018 to May 2021 were retrospectively analyzed. Parameters studies included standard motor and sensory nerve conduction studies, electromyography (EMG) and F waves studies. Correlation analysis was made to explore the relationships between clinical indicators and electrophysiological data.Results:There was statistically significant difference in the motor nerve conduction study on abnormal rate of tibial nerve (χ 2=11.08, P=0.011). Motor nerve conduction abnormalities were presented in a majority of patients with decreased motor conduction velocity (MCV) and prolonged distal motor latency (DML). There was no statistically significant difference in the overall abnormal rate between lower limbs and upper limbs (30/32, 93.8% vs 22/22, 100.0%; χ 2=1.43, P=0.508), sensory nerve conduction and motor nerve conduction (52/54, 96.3% vs 42/42, 100.0%; χ 2=1.59, P=0.503). There was statistically significant difference in the overall abnormal rate in median nerve, ulnar nerve and sural nerve (χ 2=14.96, P=0.001;χ 2=10.00, P=0.007; χ 2=9.95, P=0.008),and absent sensory nerve action potential was the most common abnormality in sensory nerve conduction abnormalities. The abnormal rate of EMG was 9/14, which was constituted by upper limbs (4/8) and lower limbs (5/6), and the spontaneous activity accompanied with prolonged duration and increased amplitude of motor unit action potential was common. Significant negative correlations were established between disease duration and compound muscle action potential (CMAP) amplitude and negative area of ulnar nerve ( r=-0.84, P=0.036; r =-0.76, P=0.011), and the correlations between age and MCV of median nerve and ulnar nerve were also found ( r=0.89, P=0.019; r=0.95, P=0.003). The DML of median nerve was negatively correlated with CMAP amplitude ( r=-0.63, P=0.049). Moreover, the correlation analysis revealed associations of the F wave latency with the DML, CMAP amplitude and MCV of tibial nerve ( r= 0.90, P=0.039; r=-0.96, P=0.012; r=-0.96, P=0.010). Conclusions:The motor nerve and sensory nerve, the myelin sheath and axon of peripheral nerves in anti-NF155 IgG4 CIDP patients were largely affected. The CMAP amplitude and negative area of ulnar nerve might be of certain clinical value in reflecting the disease duration.The younger the patients, the more severe the demyelination degree of the upper limbs. The F wave latency of tibial nerve not only reflected the abnormal proximal conduction, but also the distal damage degree of myelin sheath and axon.

GM1 improves neurofascin155 association with lipid rafts and prevents rat brain myelin injury after hypoxia-ischemia

White matter injury characterized by damage to myelin is an important process in hypoxic-ischemic brain damage (HIBD). Because the oligodendrocyte-specific isoform of neurofascin, neurofascin 155 (NF155), and its association with lipid rafts are essential for the establishment and stabilization of the paranodal junction, which is required for tight interaction between myelin and axons, we analyzed the effect of monosialotetrahexosyl ganglioside (GM1) on NF155 expression and its association with lipid rafts after HIBD in Sprague-Dawley rats, weighing 12-15 g, on day 7 post-partum (P7; N = 20 per group). HIBD was induced on P7 and the rats were divided into two groups: one group received an intraperitoneal injection of 50 mg/kg GM1 three times and the other group an injection of saline. There was also a group of 20 sham-operated rats. After sacrifice, the brains of the rats were removed on P30 and studied by immunochemistry, SDS-PAGE, Western blot analysis, and electron microscopy. Staining showed that the saline group had definite rarefaction and fragmentation of brain myelin sheaths, whereas the GM1 group had no obvious structural changes. The GM1 group had 1.9-2.9-fold more GM1 in lipid rafts than the saline group (fraction 3-6; all P < 0.05) and 0.5-2.4-fold higher expression of NF155 in lipid rafts (fraction 3-5; all P < 0.05). Injection of GM1 increased the content of GM1 in lipid rafts as well as NF155 expression and its lipid raft association in HIBD rat brains. GM1 may repair the structure of lipid rafts, promote the association of NF155 (or other important proteins) with lipid rafts, stabilize the structure of paranodes, and eventually prevent myelin sheath damage, suggesting a novel mechanism for its neuroprotective properties.

A study on the immunocytochemical localization of neurofascin in rat sciatic nerve

We examined the localization of neurofascin (NF) in the sciatic nerve of rat. In the myelinated fibers, neurofascin localizes strongly in the nodal axolemma except the small central cleft and also expresses in the paranodes, and weakly in the Schmidt-Lanterman incisures. In the paranodes, NF localizes around the axolemma and it expresses in the apposing membrane of paranodal loops. Axoplasm, compact myelin and cytoplasm of Schwann cell do not express NF at all. In the Schmidt-Lanterman incisures, NF is expressed weakly along the Schwann cell membrane. We propose that neurofascin may be a plasmalemmal integral protein of Schwann cell in the paranode and plays some important roles for the maintenance of axo-glial junctions at the paranode. It may also have some roles for maintaining the structure of Schmidt-Lanterman incisure and have some relations with proteins localizing in the node.