Brain and Nerve最新文献

AL amyloidosis is a systemic disease caused by misfolded immunoglobulin light chains deposited as amyloid fibrils in multiple organs. Peripheral neuropathy, which often presents with sensory dissociation and autonomic dysfunction, is a key initial manifestation that can occasionally be misdiagnosed as a chronic inflammatory demyelinating polyneuropathy. This review outlines clinical features and diagnostic strategies, including electrophysiological studies, nerve biopsy findings, and recent advances in treatment. Particular focus was given to the pathological mechanisms underlying neuropathy in AL amyloidosis, including axonal degeneration and myelin-Schwann cell interface abnormalities. We emphasized the importance of early diagnosis and multidisciplinary management from a neurological perspective.

A 50year-old female was diagnosed with myasthenia gravis (MG) following aspiration pneumonia. Despite treatment with prednisolone (5mg/day) and intravenous immunoglobulin (IVIg), the bulbar palsy persisted. Additionally, chest CT revealed findings suggestive of invasive thymoma or thymic carcinoma, leading to a planned thymectomy with median sternotomy. This case presents a high-risk of myasthenic crisis due to thymoma-associated MG, persistent bulbar palsy, and the need for highly invasive surgery. Therefore, enhanced immunotherapy was required to prevent this crisis, and zilucoplan was chosen because of its rapid onset of action and compatibility with IVIg. Following the initiation of zilucoplan, there was prompt improvement in the symptoms of MG. Effective preoperative control of MG led to a good clinical course, with no significant postoperative myasthenic crisis or exacerbation of symptoms. This is the first report on the use of zilucoplan for the prevention of perioperative myasthenic crisis. (Received April 14, 2025; Accepted June 3, 2025, Published August 1, 2025).

Anti-myelin-associated glycoprotein neuropathy is now recognized as a distinct clinicopathological entity. Since its initial description over 40 years ago, substantial advances have been made in elucidating its pathogenic mechanisms, standardizing diagnostic criteria, and expanding therapeutic options. Recent discoveries-including the identification of M-protein-negative presentations and the efficacy of BTK inhibitors in MYD88-mutant cases-hold considerable promise for enhancing early detection and guiding optimal treatment selection to eventually improve patient outcomes. Nevertheless, future research in this field must prioritize the validation of robust biomarkers, development of more potent disease-modifying agents, and implementation of precision-medicine strategies.

"Aphantasia" refers to the inability to create voluntary mental images. Most studies have assessed aphantasia using questionnaires; however, recently, there have been attempts to quantify aphantasia using objective measures such as pupillary reflexes and electrodermal responses. Currently, no treatment has been established, and there are many unknown aspects of brain function. Conversely, compensatory measures such as language function may likely minimize the mental distress and disruption in the lives of individuals with aphantasia.

Alzheimer's disease is an age-related neurodegenerative disorder, and is considered to contribute to dementia in 60%-70% of individuals with dementia. In recent years, a series of amyloid β protein (Aβ)-targeting antibodies that act directly on Aβ aggregates in the brain, one of the factors which contributes to the onset of Alzheimer's disease, have been approved to suppress the clinical progression, and Alzheimer's disease treatment in Japan is changing. This review article focuses on one of these Aβ-targeting antibodies, donanemab, and summarizes its clinical study results. (Received November 1, 2024; Accepted May 7, 2025; Published August 1, 2025).

M-protein and neuropathy are highly prevalent and often coincide without causal relationships. However, some M-proteins induce neuropathies, which are diverse and require a multifaceted approach to investigate M protein characteristics, neurological findings, electrical and pathological findings, and systemic complications. Even if the M protein is benign at the time of onset, neurologists must manage the risk of progression to a hematologic malignancy during the disease. This article outlines the points to be considered in daily practice from the viewpoint of a neurologist.

This article deals with the neural circuits involved in the generation and suppression of saccadic eye movements. Voluntary eye movements are known to be organized in two-dimensional horizontal and vertical coordinate system, whereas the vestibulo-ocular reflex (VOR) uses a three-dimensional semicircular canal coordinate system. However, it is generally accepted that the neural circuits for saccades and the quick phase of vestibular nystagmus share a common pathway. Despite the discrepancy, this issue has not been noticed, because the output pathway for the vertical saccade system remains poorly understood. To resolve this discrepancy, we analyzed the pathway from the superior colliculus (SC) to vertical ocular motoneurons, using intracellular recording and staining techniques. We found that the saccade system and the vestibuloocular system share the common semicircular coordinate system. Based on this saccade generation circuit, we proceeded to analyze the saccade trigger system. Our results showed that the saccade-triggering signal originates from the saccade-driving pathway in the SC, passing through inhibitory burst neurons, to suppress the tonic firing of inhibitory omnipause neurons in the raphe nucleus. This triggering mechanism is then discussed in relation to the suppression pathway for saccades during fixation and active vision.

POEMS syndrome is a systemic disease characterized by monoclonal plasma cell proliferation and the overproduction of the vascular endothelial growth factor. Japanese researchers have made significant contributions to the establishment of disease concepts and the development of treatments. Although many aspects of the pathophysiology remain unclear, therapies that target plasma cells have the potential to markedly improve the prognosis of affected individuals. However, the only drug currently approved for the treatment of this syndrome is thalidomide, which was authorized in 2021. Numerous challenges need to be addressed to further improve patient outcomes.

Sporadic late-onset nemaline myopathy (SLONM) is distinct from congenital nemaline myopathies, which are associated with genetic abnormalities. There are many cases of SLONM with M-proteinemia, but treatment response and life expectancy are poor. Several studies have reported that patients with M protein-positive SLONM treated with high-dose melphalan combined with autologous hematopoietic stem cell transplantation (HDM-ASCT) presented good long-term outcomes. These reports suggest that early diagnosis is important, however, it is often time-consuming to diagnose or may be misdiagnosed as other conditions. In recent years, knowledge of the pathology of SLONM and nemaline myopathies has gradually increased. This article provides an overview of SLONM, focusing on the characteristic clinical and myopathological findings.

Autism spectrum disorder is characterized by socio-communicative traits and cognitive inflexibility. Here, we present a series of findings indicating that autistic neural rigidity is a key neural mechanism underpinning for both social and non-social symptoms. In addition, we present our recent observation that these core autistic symptoms can be mitigated by alleviating neural rigidity using our unique closed-loop non-invasive neural stimulation system.