Atsuhiko Sugiyama

Reconstruction magnetic resonance neurography in chronic inflammatory demyelinating polyneuropathy.

To study distribution and patterns of nerve hypertrophy in chronic inflammatory demyelinating polyneuropathy (CIDP), magnetic resonance neurography with 3‐dimensional reconstruction of short tau inversion recovery images was performed in 33 patients. This technique clearly showed longitudinal morphological changes from the cervical roots to the nerve trunks in the proximal arm. Nerve enlargement was detected in 88% of the patients. According to the clinical subtype of CIDP, typical CIDP patients showed symmetric and root‐dominant hypertrophy, whereas Lewis–Sumner syndrome patients had multifocal fusiform hypertrophy in the nerve trunks. The patterns of nerve hypertrophy presumably reflect the different pathophysiology of each CIDP subtype. Ann Neurol 2014.

First adult case of Helicobacter cinaedi meningitis

Helicobacter cinaedi, a gram-negative spiral bacillus that inhabits the intestinal tracts of rodents and primates, is associated with gastroenteritis in humans. H. cinaedi infection has been commonly reported in immunocompromised individuals such as human immunodeficiency virus-infected patients, but rarely in immunocompetent individuals. Prior contact with animals has attracted attention as a possible source of H. cinaedi infection. We report a case of meningitis in an immunocompetent 34-year-old woman who had daily contact with a kitten for a month. She developed acute headaches, fevers, and chills. Neurological examination revealed neck stiffness and her cerebrospinal fluid (CSF) exhibited polymorphonuclear pleocytosis and a decreased concentration of glucose. Blood and CSF cultures were negative; however, the pathogen responsible for her condition was identified as H. cinaedi by polymerase chain reaction in CSF. This is the first adult case of meningitis caused by H. cinaedi. Thus, this bacillus should be considered a possible causative agent of bacterial meningitis in healthy adults.

Putaminal hypointensity on T2*-weighted MR imaging is the most practically useful sign in diagnosing multiple system atrophy: A preliminary study

OBJECTIVE To identify useful MRI abnormalities in the putamen for diagnosing multiple system atrophy. METHODS Patients with multiple system atrophy (n=15), Parkinsons disease (n=16), or progressive supranuclear palsy (n=9) and healthy controls (n=10) were enrolled. Using a visual analog scale, 4 examiners independently rated high-intensity signals along the lateral putamen on T2-weighted and T2*-weighted images, low-intensity signals within the putamen on T2-weighted and T2*-weighted images, and putaminal atrophy. Receiver operating characteristic analyses were performed, and the area under the receiver operating characteristic curve was calculated. RESULTS For differentiating multiple system atrophy from progressive supranuclear palsy, Parkinsons disease, and healthy controls, the mean area under the curve values was the highest for low-intensity signals within the putamen on T2*-weighted images (0.797, 0.867, 0.896, respectively). Variations in the area under the curve values among the 4 examiners were the smallest in low-intensity signals within the putamen on T2*-weighted images. Good inter-rater reliability was achieved for low-intensity signals within the putamen on T2*-weighted images and high-intensity signals along the lateral putamen on T2*-weighted images. CONCLUSION Low-intensity signals within the putamen on T2*-weighted images is the most useful MRI abnormality for diagnosing multiple system atrophy.

Transient global amnesia with a hippocampal lesion followed by transient epileptic amnesia

Transient epileptic amnesia (TEA) is a seizure disorder characterized by brief, recurrent attacks of amnesia in middleaged or elderly subjects, often occurring on waking, with favorable response to anticonvulsant medication [1]. While this syndrome is becoming increasingly recognized, its association with transient global amnesia (TGA) is not fully understood. It remains unknown whether TEA is a separate entity from recurrent TGA, or whether TGA can be a cause of TEA. We report a patient initially presenting with TGA and a hippocampal lesion on magnetic resonance imaging (MRI), followed by TEA episodes, suggesting that this damaged region associated with TGA may be an epileptic focus resulting in TEA.

Trigeminal root entry zone involvement in neuromyelitis optica and multiple sclerosis

Trigeminal root entry zone abnormality on brain magnetic resonance imaging has been frequently reported in multiple sclerosis patients, but it has not been investigated in neuromyelitis optica patients. Brain magnetic resonance imaging of 128 consecutive multiple sclerosis patients and 46 neuromyelitis optica patients was evaluated. Trigeminal root entry zone abnormality was present in 11 (8.6%) of the multiple sclerosis patients and two (4.3%) of the neuromyelitis optica patients. The pontine trigeminal root entry zone may be involved in both multiple sclerosis and neuromyelitis optica.

Brain gray matter structural network in myotonic dystrophy type 1

This study aimed to investigate abnormalities in structural covariance network constructed from gray matter volume in myotonic dystrophy type 1 (DM1) patients by using graph theoretical analysis for further clarification of the underlying mechanisms of central nervous system involvement. Twenty-eight DM1 patients (4 childhood onset, 10 juvenile onset, 14 adult onset), excluding three cases from 31 consecutive patients who underwent magnetic resonance imaging in a certain period, and 28 age- and sex- matched healthy control subjects were included in this study. The normalized gray matter images of both groups were subjected to voxel based morphometry (VBM) and Graph Analysis Toolbox for graph theoretical analysis. VBM revealed extensive gray matter atrophy in DM1 patients, including cortical and subcortical structures. On graph theoretical analysis, there were no significant differences between DM1 and control groups in terms of the global measures of connectivity. Betweenness centrality was increased in several regions including the left fusiform gyrus, whereas it was decreased in the right striatum. The absence of significant differences between the groups in global network measurements on graph theoretical analysis is consistent with the fact that the general cognitive function is preserved in DM1 patients. In DM1 patients, increased connectivity in the left fusiform gyrus and decreased connectivity in the right striatum might be associated with impairment in face perception and theory of mind, and schizotypal-paranoid personality traits, respectively.

Thalamic hypoperfusion and disrupted cerebral blood flow networks in idiopathic generalized epilepsy: Arterial spin labeling and graph theoretical analysis

PURPOSE The aim of this study was to investigate interictal cerebral blood flow (CBF) distributions and graph theoretical networks in idiopathic generalized epilepsy (IGE) using arterial spin labeling (ASL) imaging and anatomical covariance methods of graph theoretical analysis. MATERIAL AND METHODS We recruited 19 patients with IGE and 19 age-/gender-matched healthy controls. Their CBF images were obtained by pseudo-continuous ASL imaging and compared using statistical parametric mapping 8 software (SPM8) and Graph Analysis Toolbox (GAT). RESULTS The ASL imaging could detect interictal hypoperfusion in the thalamus, upper midbrain, and left cerebellum in IGE. Additionally, the graph theoretical analyses revealed characteristic findings of the CBF network of IGE, including significantly reduced resilience to attacks and changes of regional clustering especially in the bilateral temporo-occipital areas and lateral frontal lobes. There was no significance in the comparisons of network metrics. CONCLUSION These findings could contribute to a better understanding of the pathophysiology of IGE.

Isolated autonomic failure without evident somatic polyneuropathy in AL amyloidosis

Amyloid light-chain (AL) amyloidosis is an acquired disorder characterized by the abnormal proliferation and deposition of monoclonal immunoglobulin light chains. The frequency of neuropathy in AL amyloidosis patients is 15–20%. Paresthesia, numbness and muscle weakness are the most common symptoms of this condition [1]. Autonomic failure is also a common feature of AL amyloidosis but generally appears as part of sensorimotor polyneuropathy. In this study, we describe two AL amyloidosis cases with severe autonomic failure without either clinical or electrophysiological evidence of peripheral sensorimotor involvement. Case 1 is a 55-year-old man who had epigastric discomfort 12 months ago, but upper gastrointestinal endoscopy revealed no aberrations. He felt light headed while standing four months ago and then developed erectile dysfunction, persistent diarrhea and recurrent syncope. On examination, he could not maintain a sitting position because of orthostatic symptoms. He showed no muscle weakness or sensory abnormalities, and tendon reflexes were normal in the extremities. M protein was not detected by serum immunofixation electrophoresis. The plasma norepinephrine level in the supine position was low (64 pg/mL; reference range 100–450 pg/mL). Cerebrospinal fluid examination showed a normal cell count (0/mm) and an elevated protein level (158 mg/dL). Nerve conduction study (NCS) showed normal results (Table 1). Autonomic function tests [2] showed a generalized autonomic failure (Table 2). High-dose intravenous immunoglobulin or intravenous methylprednisolone therapy did not improve his condition. Further evaluations revealed elevated serum free light chain levels (83.5 mg/L; reference range 5.7–26.3 mg/L), normal free k light chain levels (14.6 mg/L; reference range 3.3–19.4 mg/L) and a decreased k/ ratio (0.17; reference range 0.26–1.65). Urine Bence Jones protein ( type) was detected. Congo red staining of the biopsy specimens revealed deposition of amyloid in the gastric and rectal submucosa and abdominal fat, where immunohistochemistry revealed amyloid but not amyloid k. Although he still did not show weakness and sensory abnormalities, repeat NCS (two months after the first examination) showed decreased compound muscle action potential (CMAP) and sensory nerve action potential (SNAP; Table 1). After five cycles of combination chemotherapy of bortezomib, cyclophosphamide and dexamethasone, NCS revealed improvement (Table 1). He was also treated with autologous stem cell transplantation and showed a partial improvement of orthostatic hypotension. Case 2 is a 71-year-old man who experienced recurrent syncope for the last six months. He also had constipation and erectile dysfunction. He had a history of left cerebellar infarction and arterial fibrillation at the age of 67 years. On examination, he could not maintain a sitting position because of postural symptoms. Muscle strength and sensory function were normal. Tendon reflexes were preserved in all limbs. NCS showed normal results except for slightly decreased CMAP and SNAP in the right median nerve (Table 1). His condition continued to deteriorate slowly. During reevaluation five months later, there was mild muscle weakness in the bilateral lower limbs without sensory abnormalities. Tendon reflexes were absent. M protein was not detected by serum immunofixation electrophoresis. An electrocardiogram showed left ventricular hypertrophy, and echocardiography showed high echogenicity of the Keywords

Thalamic involvement determined using VSRAD advance on MRI and easy Z-score analysis of 99mTc-ECD-SPECT in Gerstmann-Sträussler-Scheinker syndrome with P102L mutation

Gerstmann-Sträussler-Scheinker syndrome caused by the P102L mutation in the prion protein gene (GSS102) is usually characterized by the onset of slowly progressive cerebellar ataxia, with dementia occurring much later. Because of the relatively long disease course and the prominence of progressive cerebellar ataxia in the early stage, GSS102 is often misdiagnosed as other neurodegenerative disorders. We present two cases of genetically proven GSS102L, both of which present with atrophy and decreased blood flow of the thalamus as determined by voxel-based specific regional analysis system for Alzheimers disease (VSRAD) advance software and easy Z-score analysis for 99mTc-ethyl cysteinate dimer-SPECT, respectively. These thalamic abnormalities have not been fully evaluated to date, and detecting them might be useful for differentiating GSS102 from other neurodegenerative disorders.

MR Imaging Features of the Cerebellum in Adult-Onset Neuronal Intranuclear Inclusion Disease: 8 Cases

SUMMARY: Neuronal intranuclear inclusion disease is a neurodegenerative disorder pathologically characterized by eosinophilic hyaline intranuclear inclusions. A high-intensity signal along the corticomedullary junction on DWI has been described as a specific MR imaging finding of the cerebrum in neuronal intranuclear inclusion disease. However, MR imaging findings of the cerebellum in neuronal intranuclear inclusion disease have not been fully evaluated. Here, we review MR imaging findings of the cerebellum in a series of 8 patients with pathologically confirmed neuronal intranuclear inclusion disease. The MR imaging results showed cerebellar atrophy (8/8 patients) and high-intensity signal on FLAIR images in the medial part of the cerebellar hemisphere right beside the vermis (the “paravermal area”) (6/8) and in the middle cerebellar peduncle (4/8). The paravermal abnormal signals had a characteristic distribution, and they could be an indicator of the diagnosis of neuronal intranuclear inclusion disease even when using the results of past MR imaging examinations in which DWI findings were not examined.