Stage-dependent immunity orchestrates AQP4 antibody-guided NMOSD pathology: a role for netting neutrophils with resident memory T cells in situ.

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease of the CNS characterized by the production of disease-specific autoantibodies against aquaporin-4 (AQP4) water channels. Animal model studies suggest that anti-AQP4 antibodies cause a loss of AQP4-expressing astrocytes, primarily via complement-dependent cytotoxicity. Nonetheless, several aspects of the disease remain unclear, including: how anti-AQP4 antibodies cross the blood-brain barrier from the periphery to the CNS; how NMOSD expands into longitudinally extensive transverse myelitis or optic neuritis; how multiphasic courses occur; and how to prevent attacks without depleting circulating anti-AQP4 antibodies, especially when employing B-cell-depleting therapies. To address these knowledge gaps, we conducted a comprehensive 'stage-dependent' investigation of immune cell elements in situ in human NMOSD lesions, based on neuropathological techniques for autopsied/biopsied CNS materials. The present study provided three major findings. First, activated or netting neutrophils and melanoma cell adhesion molecule-positive (MCAM+) helper T (TH) 17/cytotoxic T (TC) 17 cells are prominent, and the numbers of these correlate with the size of NMOSD lesions in the initial or early-active stages. Second, forkhead box P3-positive (FOXP3+) regulatory T (Treg) cells are recruited to NMOSD lesions during the initial, early-active or late-active stages, suggesting rapid suppression of proinflammatory autoimmune events in the active stages of NMOSD. Third, compartmentalized resident memory immune cells, including CD103+ tissue-resident memory T (TRM) cells with long-lasting inflammatory potential, are detected under "standby" conditions in all stages. Furthermore, CD103+ TRM cells express high levels of granzyme B/perforin-1 in the initial or early-active stages of NMOSD in situ. We infer that stage-dependent compartmentalized immune traits orchestrate the pathology of anti-AQP4 antibody-guided NMOSD in situ. Our work further suggests that targeting activated/netting neutrophils, MCAM+ TH17/TC17 cells, and CD103+ TRM cells, as well as promoting the expansion of FOXP3+ Treg cells, may be effective in treating and preventing relapses of NMOSD.

Fifteen-Year Clinical Outcomes After Sirolimus-Eluting Stent Implantation.

BACKGROUND: Clinical outcomes after percutaneous coronary intervention have improved with the use of drug-eluting stents, but data beyond 10 years are limited. The purpose of this study was to evaluate the clinical outcomes of patients undergoing sirolimus-eluting stent implantation with follow-up beyond 10 years and to determine the impact of clinical and angiographic characteristics on long-term prognosis. METHODS AND RESULTS: The clinical outcomes of 885 patients who had undergone sirolimus-eluting stent implantation at a single institution were retrospectively reviewed. Primary endpoints included in the analysis were clinically driven target lesion revascularization (cTLR) and target lesion revascularization (TLR). Univariate and multivariate nominal logistic regression was used for data analysis. The incidence rates of cTLR and TLR beyond 10 years after sirolimus-eluting stent implantation were 16.4% and 36.8%, respectively, with cTLR tending to decrease beyond 10 years. Acute coronary syndrome was a predominant trigger for cTLR. Age, statin use, and stent restenosis emerged as predictors of cTLR within 10 years, but no significant predictors other than age were identified beyond 10 years. CONCLUSIONS: Events continue to occur beyond 10 years after sirolimus-eluting stent implantation, with a trend toward an increase in acute coronary syndromes. It is important to be vigilant about the occurrence of acute coronary syndromes during long-term follow-up.

Altered features of monocytes in adult onset leukoencephalopathy with axonal spheroids and pigmented glia: A clue to the pathomechanism of microglial dyshomeostasis.

Adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) is an autosomal-dominant type of leukoencephalopathy caused by gene mutation of colony stimulating factor 1 receptor, which is expressed mainly on monocyte lineage cells such as monocytes in the peripheral blood and microglia in the brain. Hence, microglial dysfunction is regarded as critical in the pathogenesis of ALSP. However, functional changes in these cells have not been elucidated. In this study, we report the phenotypic and functional alterations of monocytes in four patients with ALSP. Flow cytometric analysis revealed altered expression of antigen presentation- and migration-related molecules, an inflammatory shift in cytokine production and phagocytic impairment in ALSP monocytes. We speculate that the observed altered features of monocytes are mostly shared by microglial cells, leading to the clinical history and pathological characteristics of ALSP. Our analysis of PB monocytes provides novel insights into the pathogenesis of ALSP.

Signaling via toll-like receptor 4 and CD40 in B cells plays a regulatory role in the pathogenesis of multiple sclerosis through interleukin-10 production.

BACKGROUND: B cells play an important role in the development of multiple sclerosis (MS), but can also exhibit regulatory functions through IL-10 production. Toll-like receptors (TLR) and CD40 signaling are likely to be involved in this process. OBJECTIVE: To investigate the ability of MS B cells to produce IL-10 in response to TLR stimulation in the presence or absence of CD40 co-stimulation. METHODS: Peripheral blood mononuclear cells obtained from 34 MS patients and 24 matched healthy participants (HS) were stimulated through either TLR4 or TLR9 alone, or together with CD40. Intracellular cytokine production was analyzed by flow cytometry. RESULTS: The frequency of IL-10-producing cells in total B cells after either TLR9 or CD40 stimulation was significantly lower in MS than HS, regardless of disease phase. The frequency of IL-10 producing B cells after TLR4 stimulation did not differ significantly between HS and MS, regardless of disease phase. TLR4 and CD40 co-stimulation synergistically increased the frequency of IL-10-producing but not pro-inflammatory cytokine-producing B cells at MS relapse. This effect was observed in both CD27- naïve and CD27+ memory B cells. The frequency of IL-10-producing B cells following CD40 stimulation was significantly higher in interferon-ß responders than non-treated MS patients. Finally, we confirmed that the frequency of IL-10-producing B cells positively correlated with IL-10 production quantity by B cells using magnetic-isolated B cells. CONCLUSIONS: Cross-talk between TLR4 and CD40 signaling plays a crucial role in regulating IL-10 production by B cells during MS relapses, which may promote recovery from relapse. CD40 signaling in B cells is involved in the response to interferon-ß in MS. Collectively, TLR4 and CD40 signaling in B cells may provide a promising target for MS therapy.

Effect of Vericiguat on Left Ventricular Reverse Remodeling in Patients Who Have Heart Failure With Reduced Ejection Fraction　- Special Focus on Patients Without Quadruple Medical Therapy.

Background: A novel cardioprotective drug, vericiguat, reduces the risk of cardiovascular mortality for patients already on guideline-directed medical therapy. However, the effect of vericiguat on left ventricular (LV) reverse remodeling in patients with reduced LV ejection fraction (LVEF) with or without guideline-directed medical therapy, known as quadruple medical therapy, remains undetermined. Methods and Results: This study comprised 73 heart failure (HF) patients with reduced LVEF (<45%) from 5 institutions in Japan. Echocardiography was performed before and 6.1±3.9 months after administration of vericiguat. LV reverse remodeling was observed in all patients (LV end-diastolic volume 156.1±52.6 vs. 139.3±60.0 mL; P<0.001; LV end-systolic volume 108.1±41.2 vs. 91.8±51.2 mL; P<0.001; LVEF 31.8±7.4 vs. 37.6±12.3 %; P<0.001). LV reverse remodeling was also observed in 54 patients who could not undergo quadruple medical therapy for several reasons. Moreover, the incidence of cardiovascular events was also similar for patients who received or did not receive quadruple medical therapy (log-rank P=0.555). Conclusions: Significant LV reverse remodeling was observed in HF patients with reduced LVEF following administration of vericiguat. LV reverse remodeling was also observed in patients who could not receive quadruple medical therapy, thus making administration of vericiguat a potential new approach for treatment of these patients.

Clinical practice guidelines for multiple sclerosis, neuromyelitis optica spectrum disorder, and myelin oligodendrocyte glycoprotein antibody-associated disease 2023 in Japan.

BACKGROUND: The previous Japanese clinical practice guidelines for multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) were published in 2017. Recently, for the first time in 6 years, the MS and NMOSD guideline development committee revised the Japanese guidelines for MS, NMOSD, and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). METHODS: The committee utilized the Grading of Recommendations Assessment, Development, and Evaluation system based on the "Minds Handbook for Clinical Practice Guideline Development 2020 Ver. 3.0″ with a focus on clinical questions (CQs). The committee also discussed clinical issues other than CQs, categorizing them as a question-and-answer (Q&A) section, including "issues on which experts' opinions agree to a certain extent" and "issues that are important but not included in the CQ". RESULTS: The committee identified 3, 1, and 1 key CQs related to MS, NMOSD, and MOGAD, respectively, and presented recommendations. A Q&A session regarding disease-modifying therapies and relapse prevention therapies for MS, NMOSD, and MOGAD was conducted. The revised guidelines were published in September 2023. CONCLUSIONS: The Japanese guidelines for clinical practice on MS, NMOSD, and MOGAD were updated. Treatment strategies for MS, NMOSD, and MOGAD are changing, and these updated guidelines may assist with treatment decisions for these diseases in clinical practice.

Urosepsis Risk in Neuromyelitis Optica Spectrum Disorder Patients Administered Satralizumab.

Objective The interleukin-6 (IL-6) inhibitor satralizumab is an established treatment for neuromyelitis optica spectrum disorder (NMOSD). Although IL-6 inhibitors are generally well-tolerated, serious infections, including sepsis, can occur. In this study, we compared the sepsis characteristics in NMOSD patients administered satralizumab (NMOSD-satralizumab) to those in rheumatoid arthritis patients administered tocilizumab (RA-tocilizumab), another IL-6 inhibitor. Methods We examined adverse event reports from the Japanese Pharmaceuticals and Medical Devices Agency regarding NMOSD-satralizumab from August 2020 to March 2022 and RA-tocilizumab from April 2008 to November 2019 (term 1) and to March 2022 (term 2). Results We identified 6 sepsis cases in NMOSD-satralizumab, of which 5 (83%) developed from urinary tract infections (UTIs). Although data were unavailable for two patients, three cases had urologic complications in addition to recognized risk factors for serious infections, such as an older age, corticosteroid use, obesity, diabetes mellitus and motor disability. Urosepsis was relatively infrequent in RA-tocilizumab (term 1: 24.2%, term 2: 20.1%). Conclusion Safe satralizumab use requires risk factor assessment to minimize the incidence of severe infections. Management of UTIs is also recommended.

Association of cerebrospinal inflammatory profile with radiological features in newly diagnosed treatment-naïve patients with multiple sclerosis.

Objective: Multiple sclerosis (MS) is an immune-mediated demyelinating disease of the central nervous system. Without reliable diagnostic biomarkers, the clinical and radiological heterogeneity of MS makes diagnosis difficult. Although magnetic resonance imaging (MRI) is a major diagnostic tool for MS, the association of MRI findings with the inflammatory profile in cerebrospinal fluid (CSF) has been insufficiently investigated. Therefore, we focused on CSF profile of MS patients and examined its association with MRI findings. Methods: Concentrations of 26 cytokines and chemokines were determined in CSF of 28 treatment-naïve MS patients and 12 disease-control patients with aquaporin-4 antibody-seropositive neuromyelitis optica spectrum disorder (NMOSD). Results: High levels of interleukin (IL)-6, IL-17A, B-cell activating factor (BAFF), a proliferation inducing ligand (APRIL), and CD40 ligand were correlated with the absence of at least one of the following three MRI findings in MS: an ovoid lesion, three or more periventricular lesions, and a nodular and/or ring-shaped contrast-enhancing lesion. The multivariate analysis revealed that elevated IL-17A was an independent predictor of absence of ovoid lesion and periventricular lesions less than three. MS patients were classified into a group with all three MRI findings (MS-full) and a group with less than three (MS-partial). The discriminant analysis model distinguished three groups: MS-full, MS-partial, and NMOSD, with 98% accuracy. Conclusion: The CSF inflammatory profile was associated with radiological findings of treatment-naïve MS. This result indicates the possible utility of combined CSF and MRI profiling in identifying different MS phenotypes related to the heterogeneity of underlying immune processes.

A tumefactive anti-MOG antibody associated disorder heralding central nervous system B-cell lymphoma: Case report on diagnostic challenge.

We present the case of a 52-year-old woman with right hemiparesis due to a mass lesion in the left parietal white matter and corpus callosum. The lesion was hyperintense on diffusion weighted image and homogenously enhanced with gadolinium on magnetic resonance imaging, and was radiologically indistinguishable with lymphoma. Following progressive aggravation of symptoms, craniotomy for biopsy of the lesion was performed, and it was revealed that the patient had anti-myelin oligodendrocyte glycoprotein-associated disease by histopathological and serological diagnosis. Initial treatment with steroid dramatically improved the symptoms, but they exacerbated again. Then, through cerebrospinal fluid examination, it was revealed that the patient had B-cell lymphoma.

T cells from MS Patients with High Disease Severity Are Insensitive to an Immune-Suppressive Effect of Sulfatide.

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS). Its early phase is characterized by a relapse-remitting disease course, followed by disability progression in the later stage. While chronic inflammation accompanied with degeneration is well-established as the key pathological feature, the pathogenesis of MS, particularly progressive MS, remains elusive. Sulfatide is a major glycolipid component of myelin, and previous studies in experimental autoimmune encephalomyelitis mouse models have demonstrated it to have immune-protective functions. Notably, sulfatide concentration is increased in the serum and cerebrospinal fluid of patients with MS, particularly those in a progressive disease course. Here, we show that the myelin-glycolipid sulfatide displays an ability to suppress the proliferation of polyclonally activated human T cells. Importantly, this suppressive effect was impaired in T cells obtained from MS patients having higher disability status. Therefore, it is plausible that progression of MS is associated with an escape from the immune-regulatory effect of sulfatide. Our study suggests that, although the precise mechanisms remain unrevealed, an escape of T cells from immunosuppression by sulfatide is associated with disease progression in the advanced stage. Further studies will provide novel insights into the pathogenesis of MS, particularly regarding disease progression, and help develop novel treatment strategies for this challenging disease.

Radiological and Laboratory Features of Multiple Sclerosis Patients With Immunosuppressive Therapy: A Multicenter Retrospective Study in Japan.

Background: Multiple sclerosis (MS) is a relapsing, inflammatory, and demyelinating disease of central nervous system showing marked clinical heterogeneity. Many factors might influence the choice of relapse prevention drug, and treatment response varies among patients. Despite the enlargement of disease-modifying drugs for MS (MS-DMDs), some patients have been treated with corticosteroid and/or immunosuppressant (CS/IS). Objective: To clarify the radiological and laboratory features of MS treated with CS/IS for relapse prevention. Methods: Clinical records including radiological and laboratory findings, and drugs used for relapse prevention were reviewed retrospectively. Results: Out of 92 consecutive MS patients, 25 (27%) were treated with CS/IS. The followings were observed less frequently in patients treated with CS/IS than in those with MS-DMDs: three or more periventricular lesions, ovoid lesions, subcortical lesions, typical contrast-enhancing lesions, negative for serum autoantibodies, and positive for oligoclonal bands in the cerebrospinal fluid. Multiple logistic regression analysis revealed that the absence of typical contrast-enhancing lesions and positivity for serum autoantibodies were independent factors associated with CS/IS prescription (odds ratio 25.027 and 14.537, respectively). Conclusion: In this cohort of Japanese patients clinically diagnosed with MS, radiological and serological findings atypical of MS were observed more frequently in patients treated with CS/IS than in those with MS-DMDs as a part of MS therapy. The absence of contrast-enhancing lesions typical of MS and positivity for serum autoantibodies were independent factors strongly associated with CS/IS use.

Immune Skew of Circulating Follicular Helper T Cells Associates With Myasthenia Gravis Severity.

OBJECTIVE: To clarify functional alterations of follicular helper T cells (Tfh) in myasthenia gravis (MG) because Tfh play important roles in helping B cells generate antibody-producing cells. METHODS: A total of 24 immunotherapy-naive patients with anti-acetylcholine receptor (AchR) antibody-positive MG and 18 age-matched healthy subjects (HS) were enrolled. Samples from 6 patients were available for posttreatment analysis. Subsets of circulating Tfh (cTfh) and B cells were identified by flow cytometry analysis of surface molecules. Cytokine production by isolated cTfh subsets from 5 patients with MG and 5 HS was measured in vitro. Analysis was performed to examine the correlation between the frequency of cTfh subsets and that of plasmablasts and between cTfh subsets and the quantitative MG score. RESULTS: cTfh increased with elevated expression of inducible T-cell costimulator (ICOS) in patients with MG. cTfh shifted to Th2 and Th17 over Th1 in MG. ICOShighcTfh produced significantly higher levels of interleukin (IL)-21, IL-4, and IL-17A than ICOSlow cTfh only in patients with MG. The frequency of cTfh within CD4 T cells was more closely associated with disease severity than the serum anti-AchR antibody titer and frequency of plasmablasts within B cells. Abnormalities of cTfh were improved after immunotherapy in parallel with clinical improvement. CONCLUSIONS: Alternation of cTfh is a key feature in the development of MG and may become a biomarker for disease severity and therapeutic efficacy. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that the level of cTfh is associated with disease severity in patients with MG.

Clinical characteristics of autoimmune disorders in the central nervous system associated with myasthenia gravis.

Myasthenia gravis (MG) is occasionally associated with autoimmune diseases in the central nervous system (CNS), such as neuromyelitis optica spectrum disorder (NMOSD), multiple sclerosis (MS), Morvan syndrome, and anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis. Here, we report five original cases associated with autoimmune disorders in the CNS among 42 patients with MG in a single tertiary hospital in Japan (11.9%). In four of these five cases, the second disease developed when the preceding disease was unstable. Accurate diagnosis of the newly developing disease may be difficult in such cases, because some neurological symptoms can be seen in both disorders. This implies the great importance of recognizing the possible co-occurrence of MG and disorders in the CNS. In addition, a comprehensive review of the literature revealed distinct clinical characteristics depending on the associated disease in the CNS, including thymic pathology and temporal relationship between MG and associated CNS disorders. Notably, NMOSD usually develops after the onset of MG and thymectomy, in clear contrast to MS. Thymoma is highly prevalent among patients with Morvan syndrome, in contract to cases with NMOSD and MS. The analysis of clinical characteristics, representing the first such investigation to the best of our knowledge, suggests different pathogeneses of these autoimmune diseases in the CNS, and provides significant implications for clinical practice.

Persistent microscopic active inflammatory lesions in the central nervous system of a patient with neuromyelitis optica treated with oral prednisolone for more than 40 years.

We have reported an autopsy case of neuromyelitis optica (NMO) that exhibited persisting active inflammatory lesions in the central nervous system (CNS) despite a 45-year-long treatment with oral corticosteroids. To our knowledge, our case had received the longest course of maintenance treatment. This case study suggests that the current treatment of NMO with immunosuppressive agents may offer a good prospect for improving life expectancy. On the other hand, it also suggest that microscopic active lesions which were clinically silent and difficult to detect by neurological examination or MRI studies may persist in the CNS in patients with NMO, despite prolonged and continuous immunosuppressive treatment.

Altered T cell phenotypes associated with clinical relapse of multiple sclerosis patients receiving fingolimod therapy.

Multiple sclerosis (MS) is a T cell-mediated autoimmune disease. Fingolimod, a highly effective disease-modifying drug for MS, retains CCR7+ central memory T cells in which autoaggressive T cells putatively exist, in secondary lymphoid organs, although relapse may still occur in some patients. Here, we analyzed the T cell phenotypes of fingolimod-treated, fingolimod-untreated patients, and healthy subjects. The frequency of CD56+ T cells and granzyme B-, perforin-, and Fas ligand-positive T cells significantly increased during fingolimod treatment. Each T cell subpopulation further increased during relapse. Interestingly, T cells from fingolimod-treated patients exhibited interferon-γ biased production, and more myelin basic protein-reactive cells was noted in CD56+ than in CD56- T cells. It is likely that the altered T cell phenotypes play a role in MS relapse in fingolimod-treated patients. Further clinical studies are necessary to investigate whether altered T cell phenotypes are a biomarker for relapse under fingolimod therapy.

Utility of SPM8 plus DARTEL (VSRAD) combined with magnetic resonance spectroscopy as adjunct techniques for screening and predicting dementia due to Alzheimer's disease in clinical practice.

We validated the utility of SPM8 plus DARTEL (VSRAD) combined with magnetic resonance spectroscopy (1H MRS) as an adjunct screening technique for dementia due to Alzheimer's disease (AD). We examined the posterior cingulate gyri of 228 subjects using VSRAD and 1H MRS in addition to conventional cerebrospinal fluid biomarkers at baseline. At the 3-year follow-up, the 228 subject were classified as follows: 93 healthy subjects, 42 MCI-non-converters (MCI-NC), 25 MCI-converters to AD (MCI-C), 44 AD, 8 dementia with Lewy bodies (DLB), 5 normal pressure hydrocephalus, and 11 patients with other neurological diseases. Our results demonstrated that subjects with increased medial temporal atrophy (MTA) severity on VSRAD, increased Cho/Cr, MI/Cr ratio, and decreased NAA/Cr and NAA/MI ratio on 1H MRS at baseline were at risk of dementia due to AD. Receiver operating characteristic analysis showed that severity of MTA and the NAA/MI ratio distinguished patients with AD and MCI-C from controls. Furthermore, the 118 subjects without dementia and MTA showing only a decreased NAA/MI ratio at baseline developed to MCI-C, AD, and DLB 3 years later. 1H MRS detected biochemical abnormalities preceding brain atrophy and cognitive decline. VSRAD combined with 1H MRS may be routinely applied to screen for MCI/AD and prodromal AD in clinical practice.

Sjögren syndrome presenting with encephalopathy mimicking Creutzfeldt-Jakob disease.

A 61-year-old man developed subacute progressive dementia, general fatigue, a tonic-clonic seizure, and a decreased level of consciousness. He had a past history of chronic hepatitis type C and was diagnosed as having hepatic encephalopathy due to hyperammonemia. His level of consciousness did not improve even though the serum ammonia level improved. In addition, he had repeated general myoclonic seizures. Head MRI (diffusion-weighted imaging) showed high signal intensities in the right thalamus and the cerebral cortices in the frontal, temporal and parietal lobes (predominantly on the right side). An electroencephalogram (EEG) showed periodic lateralized epileptic discharges (PLEDs). Cerebrospinal fluid analysis revealed high total tau protein and 14-3-3 protein levels. This case was diagnosed as Creutzfeldt-Jakob disease (CJD) based on these clinical data. However, the patient gradually improved without specific treatment. The differential diagnosis was reconsidered, and an increased erythrocyte sedimentation rate and positive serum anti-SS-A and anti-SS-B antibodies were noted. A diagnosis of Sjögren syndrome (SjS) was finally made based on a biopsy of a minor salivary gland showing infiltration of lymphocytes around the gland ducts. Steroid therapy (prednisolone 40mg/day orally) was given, and his clinical condition improved. The lesions on the head MRI decreased, and the EEG findings normalized. This case suggests that SjS has a wide spectrum, including neurological disorders, and that SjS should be considered in the differential diagnosis of CJD.

Demyelinating features in sensory nerve conduction in Fisher syndrome.

OBJECTIVE: A significant number of patients with Fisher syndrome (FS) exhibit sensory symptoms in addition to the classical triad of opthalmoplegia, ataxia and areflexia. Previous studies have shown the amplitudes of sensory nerve action potentials (SNAPs) to decrease in patients with FS, thus implying the presence of an axonal pathology in the sensory nerves. METHODS: We included ten consecutive patients with FS who were divided into the following two groups: those with hypesthesia (group H) and those without hypesthesia (group NS). The parameters obtained from nerve conduction studies (amplitudes of compound muscle action potentials, motor conduction velocities, amplitudes/duration of SNAPs and sensory conduction velocities) were retrospectively compared between the two groups. In addition, follow-up sensory nerve conduction studies were conducted in one representative patient from each group. RESULTS: Of the 10 patients with FS, four (40%) showed hypesthesia and eight (80%) showed distal paresthesia. The amplitudes of the SNAPs of both the median and sural nerves were lower in group H than in group NS. Moreover, the duration of the sural SNAPs was longer in group H than in group NS. Desynchronization of SNAPs in the acute phase was observed during follow-up in both patients who underwent follow-up studies. CONCLUSION: The prolonged duration of SNAPs in group H and the desynchronization of SNAPs in the two patients who underwent follow-up studies suggest the presence of a concomitant demyelinating process in the sensory nerves.

Top of the basilar syndrome in a young adult initially presenting with a convulsive seizure.

A 23-year-old man was admitted to our hospital due to loss of consciousness and a generalized convulsive seizure. He was diagnosed as having primary epilepsy and treated with antiepileptic drugs. Emergency CT scan of the head showed no abnormality. However, MRI scan of the head several days after admission revealed fresh infarctions caused by occlusion of the basilar artery, i.e., "top of the basilar" syndrome. This case indicates the need for precise differential diagnosis of convulsive seizure in an emergency situation. It should also be borne in mind that basilar occlusion with 'onset seizure' can occur even in young adults who have no risk factors for stroke.