Shoji Kawashima

Pasteurella multocida meningitis caused by kissing animals: a case report and review of the literature

Pasteurella multocida is a rare cause of meningitis. It is a Gram-negative coccobacillus that is a normal inhabitant of the nasopharynx or gastrointestinal tracts in animals. In humans, P. multocida has been reportedly responsible for secondary infections via domestic animals. Although it generally shows low pathogenicity in healthy individuals, exposure to domestic animals may increase the risk of infection. P. multocida should be considered as a potential cause of meningitis when a patient has experienced close contact with animals. A 44 year-old female complained of severe headache with nausea. Physical examination showed high-grade fever but no infectious symptoms and no signs of scratch wounds. She was alert and focal neurological signs were absent, but she complained of neck stiffness. Laboratory examination revealed a white blood cell count of 14,200/ mm (89.6% neutorophils), 4.2% HbA1c, and a negative HIV-1 serology. Chest X-ray and brain computed tomography findings were also normal. An initial cerebrospinal fluid (CSF) examination showed 2,880 cells/ll, an elevated protein level (156 mg/dl), and reduced glucose (51 mg/dl). Gram-negative rods were detected in the CSF by Gramstaining. The patient was therefore diagnosed with bacterial meningitis. Empiric therapy was started immediately with antibiotics, including high-dose meropenem (4 g/day) and vancomycin (2 g/day). P. multocida was isolated from blood and CSF. Based on the results of antibiotic susceptibility tests, meropenem treatment was continued for a week. Closer inspection revealed no underlying disease causing the bacterial meningitis. Her condition improved, with no neurological sequelae. On interview, she was found to have a habit of kissing her dog’s face and feeding it by transferring food mouth-to-mouth. The current case shows the typical symptoms and CSF findings of bacterial meningitis. Pasteurella multocida was isolated as the causative microorganism. Pasteurella multocida very occasionally produces infectious disease in humans, but its carriage rate in dogs, especially in the oral cavity, is high (12–75%) [3]. There have been some reports of animal bites resulting in symptoms of P. multocida infection in humans, including sepsis and cellulitis [5]. An overview of the literature on P. multocida meningitis between 1989 and 2009 suggests that animal kissing, as well as animal bites, can also cause this type of meningitis in healthy adults (Table 1) [1, 2, 6–10]. Patients with P. multocida meningitis occasionally have other, concomitant neurological diseases, such as epidural empyema and/ or encephalitis (Table 1) [2, 6–10]. Green et al. [2] reported that neurological complications were present in 17% (5/17 cases) of patients of P. multocida meningitis, based on an overview of case reports between 1989 and 1999. Analysis of a further 36 cases, in addition to the seven cases from 2000 to 2009, suggested a prevalence of neurological complications in patients with P. multocida of 22.2% (8/36 cases), which is similar to the reported prevalence in patients with bacterial meningitis caused by common bacteria. Penicillin was the most frequently used therapy in patients with P. multocida meningitis (Table 1) [2, 6–10]. However, penicillin-resistant P. multocida have been reported in rare cases [4]. We used meropenem and vancomycin as empiric antibiotics, to provide initial, broadspectrum coverage. S. Kawashima N. Matsukawa (&) Y. Ueki M. Hattori K. Ojika Department of Neurology, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan e-mail: norim@med.nagoya-cu.ac.jp

Changes in Striatal Dopamine Release Associated with Human Motor-Skill Acquisition

The acquisition of new motor skills is essential throughout daily life and involves the processes of learning new motor sequence and encoding elementary aspects of new movement. Although previous animal studies have suggested a functional importance for striatal dopamine release in the learning of new motor sequence, its role in encoding elementary aspects of new movement has not yet been investigated. To elucidate this, we investigated changes in striatal dopamine levels during initial skill-training (Day 1) compared with acquired conditions (Day 2) using 11C-raclopride positron-emission tomography. Ten volunteers learned to perform brisk contractions using their non-dominant left thumbs with the aid of visual feedback. On Day 1, the mean acceleration of each session was improved through repeated training sessions until performance neared asymptotic levels, while improved motor performance was retained from the beginning on Day 2. The 11C-raclopride binding potential (BP) in the right putamen was reduced during initial skill-training compared with under acquired conditions. Moreover, voxel-wise analysis revealed that 11C-raclopride BP was particularly reduced in the right antero-dorsal to the lateral part of the putamen. Based on findings from previous fMRI studies that show a gradual shift of activation within the striatum during the initial processing of motor learning, striatal dopamine may play a role in the dynamic cortico-striatal activation during encoding of new motor memory in skill acquisition.

Differences in dopaminergic modulation to motor cortical plasticity between Parkinson's disease and multiple system atrophy.

Dopamine modulates the synaptic plasticity in the primary motor cortex (M1). To evaluate whether the functioning of the cortico-striatal circuit is necessary for this modulation, we applied a paired associative stimulation (PAS) protocol that comprised an electric stimulus to the right median nerve at the wrist and subsequent transcranial magnetic stimulation of the left M1, to 10 patients with Parkinsons disease (PD) and 10 with multiple system atrophy of the parkinsonian type (MSA-P) with and without dopamine replacement therapy (-on/off). To investigate the M1 function, motor-evoked potentials (MEPs) were measured before and after the PAS. In both patient groups without medication, the PAS protocol failed to increase the averaged amplitude of MEPs. The dopamine replacement therapy in PD, but not in MSA-P effectively restored the PAS-induced MEP increase. This suggests that not the existence of dopamine itself but the activation of cortico-striatal circuit might play an important role for cortical plasticity in the human M1.

Inclusion criteria provide heterogeneity in baseline profiles of patients with mild cognitive impairment: comparison of two prospective cohort studies

Background Mild cognitive impairment (MCI) is considered to represent a transitional stage between ageing and Alzheimers disease (AD). To aim at identifying neuroimaging measures associated with cognitive changes in healthy elderly and MCI patients, longitudinal multicentre studies are ongoing in several countries. The patient profiles of each study are based on unique inclusion criteria. Objectives The purpose of the study is to clarify differences in baseline profiles of MCI patients between Studies on Diagnosis of Early Alzheimers Disease—Japan (SEAD-J) and Alzheimers Disease Neuroimaging Initiative (ADNI) and to examine the association between baseline profiles and risk of early conversion to AD. Design Prospective cohort study. Setting and participants SEAD-J recruited 114 patients from nine facilities in Japan. A total of 200 patients in ADNI with fluorodeoxyglucose–positron emission tomography (FDG-PET) were enrolled from the USA. Methods Baseline profiles were statistically analysed. For FDG-PET at a time of inclusion, associations between each profile and cerebral metabolic rate for glucose (CMRgl) were examined using SPM5 software. In each study, the ratio of conversion to AD within the 1-year and 2-year period after inclusion was investigated and differences in baseline profiles between AD converters and non-converters were analysed. Results SEAD-J included MCI patients with more severe verbal memory deficits and extracted patients with higher depressive tendencies. These differences were likely to be associated with criteria. SEAD-J exhibited a higher rate of conversion within 1 year compared with ADNI (24.5% vs 13.5%). In FDG-PET analyses of SEAD-J, AD converters within 1 year showed more severe decrease of FDG uptake in bilateral inferior parietal regions compared with non-converters. Conclusions Different inclusion criteria provided differences in baseline profiles. The severity of memory deficit might cause increase of the AD conversion within 1 year. Clinical outcomes of multicentre studies for early diagnosis of AD should be interpreted carefully considering profiles of patients.

Predicting the motor outcome of acute disseminated encephalomyelitis by apparent diffusion coefficient imaging: Two case reports.

We present two cases of young adults with acute disseminated encephalomyelitis (ADEM) who developed severe conscious and motor disturbances. Despite their similar initial clinical course and MRI findings, their motor function outcomes were quite different. In both cases, fluid attenuated inversion recovery (FLAIR) sequenced MRI showed multiple symmetric hyperintense lesions in the internal capsule and the brainstem at the subacute stage. However, in case 1 the apparent diffusion coefficient (ADC) was pathologically decreased in the internal capsule, whereas the ADC for case 2 was normal. At the end of the examination period, severe motor disability (bedridden state) with brain atrophy apparent on MRI remained in case 1, whereas case 2 made an almost full recovery without brain atrophy. These two cases suggest that altered ADC in the internal capsules at the subacute stage may reflect a different pathogenesis between cytotoxic and vasogenic edema, and may be a valuable indicator for the prognosis of motor disturbance.

Postsurgical propriospinal myoclonus emerging at wake to sleep transition

1389-9457/

Idiopathic trigeminal neuropathy with trigeminal mass lesion on MRI: Neoplasm or not?:

see front matter 2013 Elsevier B.V. All rights reserved. doi:10.1016/j.sleep.2013.07.020 ⇑ Corresponding author. Address: Department of Neurology and Neuroscience, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuhoku, Nagoya, Aichi 467-8601, Japan. Tel.: +81 (0) 52 853 8094; fax: +81 (0) 52 852 3590. E-mail address: toguri@mac.com (T. Oguri). sleep/) Guide for Authors for instructions. We hope this section will be enriched by the contributions of our colleagues who wish to offer stimulating opportunities for discussion and new insights into the field of sleep.

Early treatment for IgG4-related disease may prevent cognitive impairment caused by cerebral vasculitis: A case report and review of the literature

The objective of the present study was to investigate clinical and magnetic resonance imaging (MRI) features of idiopathic trigeminal neuropathy with transient MR abnormalities mimicking a neoplasm (ITNmn). We retrospectively evaluated clinical and MRI features in two cases of ITNmn seen in our institution in comparison with those of previously reported five cases. The most common symptom was altered facial sensation and numbness limited to one or more trigeminal nerve divisions (100%). ITNmn commonly affected not only the second and third divisions (86% and 57%, respectively) but also the first division (71%). The most common findings on MRI were enlargement and gadolinium enhancement of the trigeminal nerve, which were similar to those seen in neoplasms (100%). The abnormalities spontaneously regressed in all five evaluable cases. ITNmn should be added in the differential diagnosis of non-specific mass-like lesions in trigeminal neuropathy and be observed carefully without surgical treatment.

Reduced striatal dopamine release during motor skill acquisition in Parkinson’s disease

IgG4-related disease (IgG4-RD) is a recently recognized disease entity. A 74-year-old male presented with transient headache. He was diagnosed IgG4-RD by pancreatic biopsy at the age of 72. Magnetic Resonance Imaging (MRI) showed disseminated cerebral microbleeds and microinfarctions in time and space. It suggested cerebral vasculitis, however any causative factor were not confirmed. IgG4-RD rarely causes cerebral vasculitis. This might be a first case of an asymptomatic cerebral vasculitis due to IgG4-RD. Patient was started on oral prednisolone, and no neurological or neuropsychological symptom was clinically observed. The MRI findings improved after treatment, and revealed no indication of newly lesions at 6-months follow-up. Early treatment for IgG4-RD may be recommended to prevent irreversible cognitive dysfunction.

Impairment of the spatial working memory in Parkinson's disease with MCI: A fMRI study using n back task

Background Striatal dopamine is functionally important for the acquisition of motor skills. However, it remains controversial as to whether intrinsic processing of motor learning is impaired in patients with Parkinson’s disease (PD), and if yes, whether the impairment is associated with altered striatal dopamine release. Additionally, most neuro-imaging studies of patients with PD have focused on motor sequence learning. In contrast, skill acquisition, specifically, the reconstruction of muscle control of isolated movements, has barely been studied. Method In this study, we used a repetitive skill training task to measure the peak acceleration of left thumb movement during a process to achieve fine tuning of motor skill. Using 11C-raclopride (RAC) positron emission tomography, we investigated changes in striatal dopamine levels in two conditions of a skill acquisition task: initial skill training (Day 1) and acquired condition (Day 2) with eight patients with PD and age-matched healthy subjects (HS). Result In HS, the mean acceleration of each session improved through repeated training sessions on Day 1. However, in patients with PD, the training-associated increase was less than that for HS, and this suggests that repetitive skill training does not result in the effective improvement of motor performance. The regions of interest (ROI) analysis revealed that the RAC-binding potential (BP) was significantly reduced in the right putamen on Day 1 compared with Day 2 in HS. In patients with PD, BP within the right putamen was unchanged. Further, we found that patients with PD had increased dopamine levels within the right ventral striatum (VST) and right caudate (CAU) on Day 2, which was greater than that in HS. These results suggest the impaired activation of the putamen during skill acquisition in patients with PD and compensated hyperactivation of the VST and CAU for the reduced dopamine release within the dorsal putamen (DPU). Conclusion Our findings suggest that patients with PD had insufficiency in the process to improve motor skills. Different patterns of striatal dopamine release are relevant to the impairment of these motor functions in patients with PD, at the early stage of the disease.