Aseptic Meningitis as an Initial Manifestation of Anti-myelin Oligodendrocyte Glycoprotein Antibody-associated Disease.

Antibody against myelin oligodendrocyte glycoprotein (MOG-IgG) associated encephalitis is an important syndrome associated with MOG-IgG. However, there have been no reports of MOG-IgG-associated optic neuritis or demyelination following meningitis without encephalitic symptoms. A 55-year-old woman presented to our hospital with headache, nausea, fever, and nuchal rigidity that had persisted for more than a month. She was hospitalized due to aseptic meningitis and recovered with conservative therapy. However, she was re-admitted due to left optic neuritis and demyelinating lesions. We diagnosed MOG-IgG-associated neuromyelitis optica spectrum disorder (NMOSD). She responded to treatment with intravenous methylprednisolone and oral prednisolone. Aseptic meningitis may be an initial manifestation of MOG-IgG-positive NMOSD.

Cortical microinfarcts in patients with multiple lobar microbleeds on 3 T MRI.

The pathogenesis of cortical microinfarcts (CMIs) is considered to be heterogeneous including cerebral small vessel disease (SVD) such as hypertensive vasculopathy (HV) and cerebral amyloid angiopathy (CAA). Recent advances in MRI have enabled the detection of CMIs in vivo. To investigate the characteristics of CMIs in advanced cerebral SVD, we performed a retrospective analysis of 85 patients with cognitive impairment who had multiple lobar cerebral microbleeds (CMBs) on 3 T MRI. Among them, 41 (48.2%) patients were classified into the strictly lobar CMB group (i.e. probable-CAA group), and 44 (51.8%) patients were classified into the non-lobar with lobar CMBs group (i.e. mix-CMBs group). The relationship between CMIs and CMBs, cortical superficial siderosis (cSS) and white matter hyperintensity was evaluated. Nine of the 41 (22.0%) patients with probable-CAA had a total of 19 CMIs, while 12 of the 44 (27.3%) patients with mix-CMBs had a total of 38 CMIs. In the probable-CAA group, the presence of CMIs was significantly associated with the presence of cSS (p < 0.001). In addition, a close spatial association between CMIs and cSS was observed. On the contrary, in the mix-CMB group, the presence of CMIs was significantly associated with the number of lobar CMBs in the frontal lobe (p = 0.034). Our results suggest that CMIs in the probable-CAA may be attributable to more severe CAA, while CMIs in the mix-CMBs indicate an advanced HV, especially when observed with more numerous lobar CMBs.

Comparative Analysis of Cortical Microinfarcts and Microbleeds using 3.0-Tesla Postmortem Magnetic Resonance Images and Histopathology.

Microvascular lesions including cortical microinfarctions (CMIs) and cerebral lobar microbleeds (CMBs) are usually caused by cerebral amyloid angiopathy (CAA) in the elderly and are correlated with cognitive decline. However, their radiological-histopathological coincidence has not been revealed systematically with widely used 3-Tesla (3T) magnetic resonance imaging (MRI). The purpose of the present study is to delineate the histopathological background corresponding to MR images of these lesions. We examined formalin-fixed 10-mm thick coronal brain blocks from 10 CAA patients (five were also diagnosed with Alzheimer's disease, three with dementia with Lewy bodies, and two with CAA only) with dementia and six non CAA patients with neurodegenerative disease. Using 3T MRI, both 3D-fluid attenuated inversion recovery (FLAIR) and 3D-double inversion recovery (DIR) were examined to identify CMIs, and T2* and susceptibility-weighted images (SWI) were examined to identify CMBs. These blocks were subsequently examined histologically and immunohistochemically. In CAA patients, 48 CMIs and 6 lobar CMBs were invariably observed in close proximity to degenerated Aß-positive blood vessels. Moreover, 16 CMIs (33%) of 48 were detected with postmortem MRI, but none were seen when the lesion size was smaller than 1 mm. In contrast, only 1 undeniable CMI was founded with MRI and histopathology in 6 non CAA patients. Small, cortical high-intensity lesions seen on 3D-FLAIR and 3D-DIR images likely represent CMIs, and low-intensity lesions in T2* and SWI correspond to CMBs with in vivo MRI. Furthermore, a close association between amyloid-laden vessels and these microvascular lesions indicated the contribution of CAA to their pathogenesis.

Complement Activation in Capillary Cerebral Amyloid Angiopathy.

BACKGROUND: Cerebral amyloid angiopathy (CAA) is classified as type 1 with capillary amyloid ß (Aß) or type 2 without capillary Aß. While it is known that CAA activates complement, an inflammatory mediator, there is no information on the relationship between capillary Aß and complement activation. METHODS: We evaluated 34 autopsy brains, including 22 with CAA and 12 with other neurodegenerative diseases. We assessed the vascular density of CAA by analyzing the expression of complement (C1q, C3d, C6, C5b-9), macrophage scavenger receptor (MSR), and apolipoprotein E (ApoE). RESULTS: Capillary immunostaining for C1q, C3d, MSR, and ApoE was identified almost exclusively in CAA-type1 brains. There was intense expression of C1q, C3d, MSR, and ApoE, as well as weaker expression of C5b-9 and C6 in the arteries/ arterioles of both CAA subtypes, but not in control brains. C5b-9 and C6 were preferentially expressed in arteries/arterioles with subcortical hemorrhage or cortical superficial siderosis. Triple immunofluorescence revealed that C1q, C3d, and ApoE were colocalized with Aß in CAA brain capillaries. CONCLUSION: Complement, MSR, and ApoE were only coexpressed in the presence of Aß accumulation in capillaries, suggesting a role for complement activation in the propagation of Aß. Additionally, C5b-9 expression may be associated with hemorrhagic brain injury in CAA.

Clinical and neuropathological findings in a patient with familial Alzheimer disease showing a mutation in the PSEN1 gene.

Over 100 mutations have been described in the presenilin-1 gene (PSEN1), resulting in familial Alzheimer disease (AD). However, of the limited number of autopsy cases, only one has been reported from an AD family with an L420R PSEN1 mutation. We describe here clinical and neuropathological features of a patient with dementia-parkinsonism from a family with a PSEN1 mutation (L420R). A 43-year-old Japanese woman was autopsied 12 years after the onset of her progressive dementia and 4 years after the onset of parkinsonism. Throughout the neocortex and hippocampus, cotton wool plaques were identified, densely packed, in almost all the cortical layers along with neuronal loss, gliosis, NFT and neuropil threads. In addition, CAA affecting meningeal, subpial and cortical arterioles was found, as well as amyloid ß-protein (Aß)-deposition in the capillaries (capillary CAA) in the neocortex and subcortical nuclei. There was loss of pigmented neurons in the substantia nigra. The putamen was densely packed with diffuse plaques and rarely showed capillary CAA, whereas the globus pallidus showed extensive capillary CAA but no plaques. This differential distribution is similar to that reported for a previous patient with a mutation in PSEN1. It is concluded that neuropathological changes in the substantia nigra and lenticular nuclei were responsible for the patient's parkinsonism. Capillary transport of Aß unique to the respective tissue of the patient may result in the differential distribution of Aß between the putamen and globus pallidus seen in individuals with a PSEN1 mutation.

In vivo detection of cortical microinfarcts on ultrahigh-field MRI.

BACKGROUND AND PURPOSE: Cortical microinfarcts (CMIs) are detected as small foci restricted to the cerebral cortex in autopsy brains. CMIs are thought to be caused by cerebral amyloid angiopathy (CAA) in the elderly and may be a risk for dementia. We aimed to visualize CMIs, which remain invisible on conventional MRI, using double inversion recovery (DIR) and 3-dimensional fluid attenuated inversion recovery (3D-FLAIR) on 3-Tesla MRI. METHODS: We prospectively performed DIR and 3D-FLAIR images in 70 subjects with Alzheimer disease (AD; n = 47), mild cognitive impairment (n = 14), AD with cerebrovascular disease (CVD; n = 3), vascular dementia (VaD; n = 2), CAA-associated intracerebral hemorrhage (ICH; n = 2) and one each of normal pressure hydrocephalus and dementia with Lewy bodies (DLB). Susceptibility-weighted imaging (SWI) was performed to detect cerebral microbleeds (CMBs). RESULTS: Nine subjects (five of AD and one each of AD with CVD, ICH, VaD, and DLB) had small intracortical high signal lesions on both DIR and 3D-FLAIR images. All the nine subjects accompanied multiple lobar CMBs. These intracortical lesions were located in close proximity to CMBs, and were suggested to be CMIs. CONCLUSIONS: DIR and 3D-FLAIR images may open a way to visualize CMIs.

[A case of delayed facial palsy following gamma knife radiosurgery for intractable trigeminal neuralgia].

A 77-year-old woman with hypertension and senile depression had suffered from medically unresponsive trigeminal (left ophthalmic) neuralgia despite microvascular decompression surgery for twice. The patient underwent stereotactic gamma knife radiosurgery (77 Gy) for the neuralgia, resulting in pain relief. However, approximately 20 months after the radiosurgery, she developed left facial palsy with hydrodipsia, left xerophthalmia, and left facial hypesthesia. Oral prednisolone was administered, and these symptoms disappeared in several months. This is the first report of facial palsy following gamma knife radiosurgery for trigeminal neuralgia.