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Dive into the research topics where Kenji Okita is active.

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Featured researches published by Kenji Okita.


Journal of Neurosurgery | 2011

Subthalamic nucleus stimulation for Parkinson disease with severe medication-induced hallucinations or delusions.

Atsushi Umemura; Yuichi Oka; Kenji Okita; Noriyuki Matsukawa; Kazuo Yamada

OBJECT Subthalamic nucleus deep brain stimulation (STN DBS) improves cardinal motor symptoms of Parkinson disease (PD) and reduces antiparkinsonian medication. Therefore, STN DBS seems to be well indicated for patients suffering from medication-induced psychotic symptoms. However, there are few available data dealing with the effect of STN DBS in this kind of patient. The authors studied the effect of STN DBS in patients with PD and severe medication-induced hallucinations or delusions. METHODS The authors retrospectively reviewed the clinical course of 10 patients who suffered from severe medication-induced hallucinations or delusions and underwent bilateral STN DBS. Patients whose preoperative thought disorder score (Unified Parkinsons Disease Rating Scale Part I, item 2) was 3 or more were enrolled in this study. All patients underwent cognitive function examination and brain perfusion SPECT preoperatively to exclude dementia with Lewy bodies. RESULTS Subthalamic nucleus DBS yielded significant improvement of motor function in all patients. In 8 patients, psychotic symptoms completely disappeared with significant reduction of dopaminergic medication. In 2 patients, hallucinations and delusions deteriorated immediately after surgery despite complete withdrawal of antiparkinsonian medication. However, these psychotic symptoms completely disappeared after a few months with administration of antipsychotics, and no recurrence was observed afterward in either patient. CONCLUSIONS Subthalamic nucleus DBS is a good treatment option for patients with PD who are suffering severe medication-induced hallucinations or delusion. However, vigilance is needed, because temporary deterioration of psychotic symptoms may occur after surgery.


Clinical Neurology and Neurosurgery | 2012

Temporary deterioration of executive function after subthalamic deep brain stimulation in Parkinson's disease.

Takehiko Yamanaka; Fumiyasu Ishii; Atsushi Umemura; Miwako Miyata; Mitsuya Horiba; Yuichi Oka; Kazuo Yamada; Kenji Okita; Noriyuki Matsukawa; Kosei Ojika

OBJECTIVE Selective impairment of executive function has been shown in Parkinsons Disease (PD) patients undergoing Deep Brain Stimulation (DBS) of the Subthalamic Nucleus (STN). However, some patients experience difficulties in daily life, such as dissension in interpersonal relationships or a loss of lifestyle balance, in the short term after surgery. Our hypothesis is that these difficulties might be related to executive dysfunction. To elucidate the involvement of executive dysfunction in these difficulties, we assessed motor and executive function in the short term and long term after surgery. METHODS We examined motor function and executive function in 30 patients who underwent bilateral STN-DBS for medically refractory PD. Patients were evaluated for executive function 1 month before surgery, 1 month after surgery, and 12 months after surgery using the Trail Making Test (TMT), the Modified Stroop Color Word Interference Test (MST) and tests of Verbal Fluency (VF). RESULTS TMT-B, TMT (B/A), MST-B, VF-phonemic and VF-semantic scores were significantly poorer 1 month after STN-DBS. TMT-B, TMT (B/A) and VF-phonemic recovered to preoperative levels by 12 months after surgery. A reduction in dopaminergic medication 1 month after surgery was significantly correlated with deterioration of TMT (B/A). CONCLUSION Temporary deterioration of executive function may occur in the short term after STN-DBS, whereas motor function is usually improved. PD patients undergoing STN-DBS should be managed during this period to better predict temporary executive dysfunction. Excessive reduction of dopaminergic medication after surgery might, at least in part, result in this deterioration of executive function.


Neuroradiology | 2010

Usefulness of 3D-PRESTO imaging in evaluating putaminal abnormality in parkinsonian variant of multiple system atrophy.

Keita Sakurai; Takatsune Kawaguchi; Tatsuya Kawai; Hiroyuki Ogino; Masaki Hara; Kenji Okita; Takemori Yamawaki; Yuta Shibamoto

IntroductionPrinciples of echo shifting with a train of observations (PRESTO) sequence has long echo time which emphasizes the effect of T2* relaxation time and contribute to its high sensitivity to the susceptibility change. The aim of our study was to evaluate the ability of 3D-PRESTO sequence in detecting putaminal hypointensity in patients with parkinsonian variant of multiple system atrophy (MSA-P) and in discriminating between MSA-P and Parkinsons disease (PD).MethodsThe signal intensity of the putamen and localization of abnormality were evaluated on 3D-PRESTO, T2*-weighted (T2*W), and T2-weighted (T2W) sequences in ten patients with MSA-P, 14 with PD, and ten controls. The putaminal signal intensity was assessed in all sequences and graded relative to the palladium. Atrophy of the putamen and posterolateral hyperintensity rim on T2W sequence were also evaluated in MSA-P patients.ResultsPutaminal hypointensity was more often seen in MSA-P than PD and controls on 3D-PRESTO sequence (p = 0.002) as well as on T2*W sequence (p = 0.003). 3D-PRESTO sequence could reveal lower intensity better than T2*W sequence in four of ten MSA-P cases. Hemi- or bilateral putaminal hypointensity, atrophy, and posterolateral hyperintensity rim were recognized in 90%, 70%, and 70% of ten MSA-P cases, respectively. Three cases revealed hypointensity on 3D-PRESTO sequence without posterolateral hyperintensity rim. Putaminal signal changes occurred in the posterolateral part with a striking lateral to medial gradient in all nine cases with putaminal hypointensity (nine out of nine, 100%).Conclusions3D-PRESTO sequence appears to be useful for depicting putaminal hypointensity in MSA-P patients and in differentiating MSA-P from PD.


Parkinsonism & Related Disorders | 2010

Predictive factors affecting early deterioration of axial symptoms after subthalamic nucleus stimulation in Parkinson's disease.

Atsushi Umemura; Yuichi Oka; Kenji Okita; Takanari Toyoda; Noriyuki Matsukawa; Kazuo Yamada

Subthalamic nucleus deep brain stimulation (STN-DBS) is an effective treatment option for medically refractory Parkinsons disease (PD). However, some patients show deterioration of axial symptoms within a short time after surgery. We studied 43 patients who underwent bilateral STN-DBS and investigated predictive factors affecting early deterioration of axial symptoms. Among 43 patients, 16 patients showed obvious deterioration of axial symptoms within three years of surgery. Multiple logistic regression analysis indicated that the significant independent variables related to early deterioration of axial symptoms were rapidly progressive short duration of the disease and advanced age at surgery. These results suggest that patients with rapidly progressing PD, who need early surgical intervention, tend to show early deterioration of axial symptoms after STN-DBS.


Cerebrovascular Diseases Extra | 2011

Plaque Vulnerability in Internal Carotid Arteries with Positive Remodeling

Toshiyasu Miura; Noriyuki Matsukawa; Keita Sakurai; Hiroyuki Katano; Yoshino Ueki; Kenji Okita; Kazuo Yamada; Kosei Ojika

Background: This study aimed to evaluate the efficacy of assessing positive remodeling for predicting future stroke events in the internal carotid artery. We therefore assessed narrowing of the carotid artery lumen using multidetector-row computer tomography (MDCT) angiography and carotid plaque characteristics using black-blood (BB) magnetic resonance (MR). Methods: We retrospectively selected 17 symptomatic and 11 asymptomatic lesions with luminal narrowing >50%. We compared remodeling parameters of luminal stenosis (remodeling ratio, RR/remodeling index, RI) using MDCT and MR intensities of atherosclerotic plaque contents using the BB technique (relative signal intensity, rSI). We also confirmed the validity of the relationship between MR intensity and atherosclerotic plaque contents by histology. The levels of biological markers related to vessel atherosclerosis were measured. Results: Plaque lesions with positive remodeling in carotid arteries were associated with a significantly higher prevalence of stroke compared with plaques with negative remodeling (p < 0.05). Radiologic and histologic analyses determined that plaques with positive remodeling had higher signal intensities (with respect to their lipid-rich content or to hemorrhage) compared with negative remodeling (correlation coefficients: RI and rSI, r = 0.41, p < 0.05; RR and rSI, r = 0.50, p < 0.05). Levels of biological markers, including high-sensitivity C-reactive protein, hemoglobin A1C, total cholesterol, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol, were not useful for predicting stroke events. Conclusions: The results of this study suggest that the combined analysis of RR, RI and rSI could potentially help to predict future stroke events.


Clinical Neurology and Neurosurgery | 2007

Recurrent limbic and extralimbic encephalitis associated with thymoma

Kenji Okita; Noriyuki Matsukawa; Manabu Hattori; Kentaro Yamada; Koji Takada; Takemori Yamawaki; Mari Yoshida; Yoshio Hashizume; Kosei Ojika

A 33-year-old woman, with a 7-year clinical history of invasive thymoma treated at ages 26 and 30 years by thymectomy and radiation, presented with a generalized convulsion and loss of consciousness. Following the seizure there was no neurological deficit and normal tendon reflexes. Magnetic resonance imaging (MRI) of the brain without gadolinium enhancement revealed multiple small lesions of high signal intensity on T2 and diffusion weighted images located in the cortical area beyond the temporal lobes. Brain biopsy demonstrated encephalitis with activated microglias and activated T-cell infiltration. Within 4 months of treatment with nothing other than anticonvulsant therapy, the lesions visible on the original MRI had completely disappeared and the patient was discharged with no neurological symptoms. The patient subsequently had two more episodes with a variety of symptoms such as incontinence, confusion, aphasia, apallial syndrome, and motor paresis. MRI following these episodes again revealed multiple lesions of similar appearance to those of the first episode, although in different locations, and much larger and more numerous. The patient had steroid pulse therapy after both episodes and the lesions noted on brain MRI disappeared within a few months with minimal neurological complications.


Biochemical and Biophysical Research Communications | 2009

Analysis of DNA variations in promoter region of HCNP gene with Alzheimer's disease.

Kenji Okita; Noriyuki Matsukawa; Mina Maki; Hideka Nakazawa; Eiichi Katada; Manabu Hattori; Hiroyasu Akatsu; Cesario V. Borlongan; Kosei Ojika

Hippocampal cholinergic neurostimulating peptide (HCNP), which enhances acetylcholine synthesis and induces cholinergic phenotype development of the septohippocampal system, is derived from HCNP precursor protein (HCNPpp), also known as phosphatidylethanolamine binding protein (PEBP) and Raf kinase inhibitor protein (RKIP). Our previous study demonstrated that expression of HCNPpp mRNA was decreased in the hippocampi of autopsied brains of Alzheimers disease (AD) patients, indicating the association of HCNP with the pathogenesis of AD. To clarify the involvement of gene variations in the promoter region of the gene encoding HCNPpp in this mRNA reduction, we analyzed DNA polymorphisms or mutations within this gene promoter region in AD patients by direct sequencing. The promoter was found to contain a CpG island without a TATA box, an element of housekeeping gene promoters. Moreover, no disease-specific polymorphisms or mutations were identified, suggesting that the decrease of mRNA can be ascribed to transcriptional or posttranscriptional changes in activity.


Polish Journal of Radiology | 2015

Internal carotid artery blister-like aneurysm caused by Aspergillus - case report.

Masaki Ogawa; Keita Sakurai; Takatsune Kawaguchi; Aya Naiki-Ito; Motoo Nakagawa; Kenji Okita; Noriyuki Matsukawa; Yuta Shibamoto

Summary Background Blister-like aneurysm of the supraclinoid internal carotid artery (ICA) is a well-documented cause of subarachnoid hemorrhage. Generally, this type of aneurysm is associated with various conditions such as hypertension, arteriosclerosis, and ICA dissection. Although Aspergillus is the most common organism causing intracranial fungal aneurysmal formation, there is no report of a blister-like aneurysm caused by Aspergillus infection. Case Report An 83-year-old man received corticosteroid pulse therapy followed by oral steroid therapy for an inflammatory pseudotumor of the clivus. Two months later, the patient was transported to an emergency department due to the diffuse subarachnoid hemorrhage, classified as Fisher group 4. Subsequent 3D computed tomography angiogram revealed a blister-like aneurysm at the superior wall of the left ICA. Six days later, the patient died of subarachnoid hemorrhage caused by the left ICA aneurysm rerupture. Autopsy revealed proliferation of Aspergillus hyphae in the wall of the aneurysm. Notably, that change was present more densely in the inner membrane than in the outer one. Thus, it was considered that Aspergillus hyphae caused infectious aneurysm formation in the left ICA via hematogenous seeding rather than direct invasion. Conclusions The blister-like aneurysm is a rare but important cause of subarachnoid hemorrhage. This case report documents another cause of blister-like aneurysms, that is an infectious aneurysm associated with Aspergillus infection.


BMC Anesthesiology | 2013

Lumbar puncture-related cerebrospinal fluid leakage on magnetic resonance myelography: is it a clinically significant finding?

Keita Sakurai; Noriyuki Matsukawa; Kenji Okita; Minoru Nishio; Masashi Shimohira; Yoshiyuki Ozawa; Susumu Kobayashi; Takemori Yamawaki; Yuta Shibamoto

BackgroundPost-dural puncture headache (PDPH) due to excessive cerebrospinal fluid (CSF) leakage is a well-known complication of lumbar puncture. Although various factors, especially the type of spinal needle, have been demonstrated to be associated with PDPH, the clinical implications of CSF leakage detected on magnetic resonance myelography (MRM) images remain unclear. The objective of this case–control study was to evaluate the association between radiologically visualized CSF leakage and PDPH.MethodsClinical data including patients’ age and gender, types of spinal needle, duration of bed rest, interval between lumbar puncture procedures and MRM studies, and incidence of PDPH were compared between patients who were radiologically-positive and -negative for CSF leakage.ResultsOf the 22 patients with definite CSF leakage on MRM images, most were asymptomatic (86%, 19/22). The remaining three patients, who were suffering from PDPH, only complained of headaches and were treated conservatively. In a review of patients’ clinical data, there were no significant differences in any parameter including the incidence of PDPH between the 22 patients who were radiologically-positive for CSF leakage and the 31 radiologically-negative patients.ConclusionThe significance of radiologically visualized CSF leakage should not be overestimated, as most such incidents are not associated with PDPH and do not require any treatment.


European Neurology | 2011

Utility of the fluid-attenuated inversion recovery sequence in detecting a hyperintense putaminal rim in multiple system atrophy-parkinsonism: a preliminary study.

Keita Sakurai; Takemori Yamawaki; Kenji Okita; Daisuke Kato; Noriyuki Matsukawa; Takatsune Kawaguchi; Susumu Kobayashi; Keiichi Nagai; Masahiro Muto; Akihiro Hosono; Yuta Shibamoto

Objective: To investigate the utility of fluid-attenuated inversion recovery (FLAIR) imaging for diagnosing multiple system atrophy-parkinsonism (MSA-P). Methods: We retrospectively evaluated 49 subjects (19 with MSA-P including 11 with early-stage disease, 15 with Parkinson’s disease and 15 matched controls) in order to compare the diagnostic value of FLAIR imaging to detect a hyperintense putaminal rim (HPR) with that of T2-weighted (T2W) imaging. Results: Compared with T2W imaging, FLAIR imaging detected HPR more conspicuously in the 19 MSA-P patients (p = 0.01); this trend was also observed in 11 early-stage MSA-P patients (p = 0.01). Furthermore, FLAIR imaging tended to increase sensitivity of detecting HPR compared with T2W imaging (all patients: 89 vs. 58%, p = 0.07; early-stage patients: 100 vs. 55%, p = 0.06). Conclusions: FLAIR imaging might be more useful for detecting HPR in MSA-P patients, even though they are at an early stage.

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Yuichi Oka

Nagoya City University

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Kosei Ojika

Nagoya City University

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