Keita Matsuura

Neuromelanin magnetic resonance imaging in Parkinson's disease and multiple system atrophy.

Pigmented neurons in the substantia nigra pars compacta (SNc) and locus coeruleus (LC) show decreased numbers differentially in Parkinsons disease (PD) and multiple system atrophy (MSA). Recent reports have described that fast spin-echo T1-weighted magnetic resonance imaging (MRI) by a 3-tesla machine can visualize neuromelanin-related contrast of the noradrenergic and dopaminergic neurons respectively in the LC and the SNc. Using neuromelanin MRI at 3 T, we investigated possible alterations of these catecholaminergic neurons in 32 PD and 9 MSA patients, and compared the results with those of 23 normal volunteers. The contrast ratio of the LC and SNc was decreased in MSA and PD patients, most prominently in the LC in MSA patients. The contrast ratio of the SNc was correlated with the Hoehn-Yahr stage of PD and the severity of neuroradiological abnormalities in MSA. These results indicate a potential diagnostic value of neuromelanin MRI to distinguish MSA patients from normal and PD patients.

Usefulness of arterial spin-labeling images in periictal state diagnosis of epilepsy

PURPOSE Arterial spin-labeling (ASL) perfusion MRI, a noninvasive method of assessing cerebral blood flow, is becoming a diagnostic tool of epilepsy. This study was undertaken to evaluate the diagnostic validity of ASL in patients with status epilepticus (SE) in a periictal state. METHOD Twenty cases with SE were studied. Patients were imaged at a 3T MRI including ASL and diffusion-weighted imaging (DWI), and were also examined using electroencephalography (EEG). The abnormal findings of ASL were compared with those obtained from DWI and EEG. RESULT Focal hyperperfusion was found in the cortical territory of 13 cases (65%). In 10 of those 13 cases, the ASL hyperperfusion region corresponded to DWI high intensity and EEG abnormality. Two cases showed hyperperfusion corresponding to EEG abnormalities in ASL despite the absence of high intensity in DWI. The remaining single case showed hyperperfusion in ASL despite the absence of high intensity in DWI and EEG abnormalities. Hyperperfusion in the subcortical territory was observed in the ipsilateral thalamus in three cases and in the contralateral cerebellum in one case. CONCLUSION Our results suggest that ASL is a useful tool to diagnose status epilepticus and localization of the epilepsy focus.

A longitudinal study of neuromelanin-sensitive magnetic resonance imaging in Parkinson's disease.

PURPOSE Neuromelanin-sensitive MR imaging (NMI) is an increasingly powerful tool for the diagnosis of Parkinsons disease (PD). This study was undertaken to evaluate longitudinal changes on NMI in PD patients. METHODS We examined longitudinal changes on NMI in 14 PD patients. The area and contrast ratio (CR) of the substantia nigra pars compacta (SNc) were comparatively analyzed. RESULTS The total area and CR of the SNc upon follow-up NMI were significantly smaller than those on initial NMI (from 33.5±18.9 pixels and 6.35±2.86% to 21.5±16.7 pixels and 4.19±2.11%; Wilcoxon signed-rank test, p<0.001 and p=0.022, respectively). The area and CR of the dominant side SNc upon initial NMI were significantly greater than those on follow-up NMI (from 15.3±9.1 pixels and 6.5±2.7% to 7.9±8.5 pixels and 3.7±2.9%; Wilcoxon signed-rank test, p=0.002 and p=0.007, respectively). On a case-by-case basis, the area of the SNc invariably decreased upon follow-up NMI in all patients. We further demonstrated that the total area and CR of the SNc negatively correlated with disease duration (Pearson correlation coefficient, r=-0.63, p<0.001 and r=-0.41, p=0.031, respectively). In area analyses, our results demonstrated very high intraclass correlation coefficients for both intra- and inter-rater reliability. CONCLUSION NMI is a useful and reliable tool for detecting neuropathological changes over time in PD patients.

STA-MCA Bypass for the Treatment of Ischemic Stroke

It is considered controversial whether superficial temporal artery (STA)-middle cerebral artery (MCA) bypass affects the outcome of patients with ischemic stroke. This prospective study was undertaken to demonstrate the effect of STA-MCA bypass on the cerebral blood flow and neurological status of the patients with ischemic stroke. Seventy-five patients underwent unilateral or bilateral STA-MCA bypass surgery. The selection of the patients closely adhered to the criteria of the Japan EC-IC Bypass Trial (JET). Cerebral blood flow (CBF) before and after Diamox administration was measured by single photon emission computed tomography (SPECT) using iodine-123-N-isopropyl-p-iodoamphetamine (IMP). MRI, contrast-enhanced 3D CT scans, and angiography were performed on each patient pre- and postoperatively. Bypass surgery was successfully done in all patients. CBF was significantly increased after STA-MCA bypass (P < 0.05). In addition, reservation of CBF was significantly improved after STA-MCA bypass (P < 0.05). Patients with transient ischemic attack (TIA) did not experience recurrence of such episodes after STA-MCA bypass. The neurological deficit was unchanged in patients with complete stroke after bypass surgery. However, the NIH stroke scale was significantly improved after bypass surgery (P < 0.01). In addition, the satisfaction rate of treatment as assessed by the patients themselves was very high after STA-MCA bypass (>90%) compared to the conservative treatment group (<50%). STA-MCA bypass still plays a limited role in the treatment of ischemic stroke, but may become a bright hope in depressed patients after cerebral ischemia.

The effectiveness of istradefylline for the treatment of gait deficits and sleepiness in patients with Parkinson’s disease

PURPOSE Istradefylline is useful in treating the wearing-off state in Parkinsons disease (PD). We investigated the effectiveness of istradefylline (ISD) in improving arousal, sleep, and gait deficits in patients with PD. METHODS We examined 14 patients with PD treated with ISD. We assessed the patients using the Unified Parkinsons Disease Rating Scale, Parkinsons Disease Questionnaire, Timed Up-and-Go test (TUG), Freezing of Gait Questionnaire (FOG-Q), Epworth Sleepiness Scale (ESS), and Parkinsons Disease Sleep Scale (PDSS) before and 1 month after ISD use. RESULTS ESS scores were significantly lower 1 month after the start of ISD treatment (6.79±6.50) than before the intervention (8.14±6.15, Wilcoxon signed-rank test, p=0.0033). PDSS scores were not significantly different 1 month after beginning the treatment (112±23mm) when compared to those before the intervention (110±27mm, Wilcoxon signed-rank test, p=0.40). TUG scores were not changed after 1 month of ISD use (14.9±8.3s) when compared to those before the intervention (21.3±30.0s, Wilcoxon signed-rank test, p=0.59). Although these measures were not significantly affected by ISD treatment, some patients remarkably improved after the treatment. FOG-Q scores were significantly lower 1 month after the beginning of treatment (9.79±7.16) than those before the intervention (12.14±5.82, Wilcoxon signed-rank test, p=0.030). CONCLUSIONS ISD may improve daytime sleepiness and FOG in patients with PD.

Istradefylline is Recommended for Morning Use: A Report of 4 Cases

We herein describe four cases of patients with Parkinsons disease who were treated with istradefylline (ISD) in the evening and had severe daytime sleepiness. The time to onset of sleepiness varied between 2 weeks to 3 months. All patients recovered after changing the timing of the ISD dosage from evening to morning. ISD is an A2A receptor antagonist with a caffeine-like arousal effect that may worsen the quality of sleep and thus increase daytime sleepiness. This report provides the first evidence of daytime sleepiness induced by evening ISD treatment. We propose that ISD should therefore only be used in the morning, particularly if taken by professional drivers.

Comparison of Premortem Magnetic Resonance Imaging and Postmortem Autopsy Findings of a Cortical Microinfarct

An 85-year-old woman diagnosed with amyotrophic lateral sclerosis died of pneumonia and was autopsied. Magnetic resonance imaging (MRI) performed 16 days before death revealed an intracortical high-intensity lesion in her right temporal cortex on three-dimensional (3D)-double inversion recovery (DIR) and 3D-fluid-attenuated inversion recovery (FLAIR) images. Histopathological examination indicated a cortical microinfarct (CMI) juxtaposed to cerebral amyloid angiopathy. Recently, in vivo detection of CMIs using 3D-DIR and 3D-FLAIR on 3-tesla MRI has been reported, and postmortem MRI study confirmed the presence of CMIs. This is the first case study to compare CMI findings detected upon premortem MRI to the CMI itself discovered upon postmortem neuropathological examination.

Diffusion tensor imaging and magnetic resonance spectroscopy in a patient with adult onset tuberous sclerosis complex

Tuberous sclerosis complex (TSC) 1 or TSC2 is mutated in most TSC patients. TSC2 mutations are more frequently associated with worse outcomes, earlier age at seizure onset, more severe intellectual disability, and higher tuber load than TSC1. The degree of white matter involvement is thought to be associated with the severity of neurological impairment. At present, genotype-phenotype correlations and relationship between tuber burden and neurological disability in TSC are debatable. We presented a 43-year-old patient with TSC2 mutation, whose symptom was only incomplete quadrantic visual field deficit in spite of multiple brain tubers. The visual field deficit was thought to be due to a small lesion in the upper medial part of the optic radiation revealed by diffusion tensor imaging. Her brain tubers showed normal findings in magnetic resonance spectroscopy. Our case suggested that neurological and neuropsychiatric manifestations of TSC are affected by the quality rather than number of the lesions. In addition, MRS may be useful to identify the correlation between brain tubers and neurological disability in TSC patients.

Clinical significance of cortical lesions in patients with multiple sclerosis: A neuropsychological and neuroimaging study

This study aims to investigate the association between the presence and frequency of cortical lesions (CLs), and the clinical and psychological features of multiple sclerosis (MS).

Proposition of zinc supplementation during levodopa-carbidopa intestinal gel treatment: XXXX

Levodopa–carbidopa intestinal gel (LCIG) infusion is a useful therapy for the wearing‐off phenomenon of advanced Parkinsons disease (PD) patients. Recently, we found three PD patients that may have had a zinc deficiency after the LCIG infusion, possibly due to the zinc‐chelating action of levodopa. This study aims to evaluate changes in serum zinc levels in three patients that received LCIG treatment and to determine possible remedies for zinc deficiency during treatment.