Power spectral analysis of heart rate variability is useful as a screening tool for detecting sympathetic and parasympathetic nervous dysfunctions in Parkinson's disease.

BACKGROUND: Parkinson's disease (PD) is a progressive neurodegenerative disorder that causes motor symptoms and autonomic dysfunction. However, autonomic function tests commonly performed in PD can only evaluate either the sympathetic or parasympathetic nervous system. Therefore, the purpose of this pilot study is to investigate whether power spectral analysis of heart rate variability could detect both sympathetic and parasympathetic nervous dysfunctions in patients with PD. METHODS: Seventeen patients with PD and 11 healthy control subjects underwent electrocardiogram recording for the spectral analysis of heart rate variability to obtain values of low-frequency (LF) (0.04-0.15 Hz) and high-frequency (HF) (0.15-0.4 Hz) powers. Moreover, we examined the coefficient of variation of R-R intervals (CVRR) as a parameter of parasympathetic function in all participants and performed 123I-metaiodobenzylguanidine scintigraphy to measure the heart-to-mediastinum ratio as a parameter of cardiac sympathetic innervation in patients with PD. RESULTS: The median age of control subjects and PD patients was 63 and 66 years old, respectively. The median Hoehn and Yahr scale of PD patients was stage 2. The values of resting LF and HF powers widely varied. The median values of resting LF powers of control subjects and PD patients and those of HF powers were 169 and 70 ms2, 279 and 65 ms2, respectively, the difference was statistically insignificant. Approximately 41% of patients with PD had values below the first quartile of resting LF powers (< 58 ms2) or HF powers (< 50 ms2); however, no control subject had such low values. Positive correlations were found between resting LF powers and heart-to-mediastinum ratios of 123I-metaiodobenzylguanidine uptake (r = 0.6) and between resting HF powers and CVRRs (r = 0.7). The resting LF power was also associated with CVRRs and constipation. Furthermore, a positive correlation was observed between resting LF powers and resting HF powers in patients with PD (r = 0.8). CONCLUSIONS: The power spectral analysis of heart rate variability may be useful as a screening tool for detecting autonomic dysfunctions by detecting low resting LF and HF powers in patients with PD. Sympathetic and parasympathetic nerves may be concurrently damaged in patients with PD.

Intracranial hemorrhage during dabigatran treatment.

BACKGROUND: The incidence of intracranial bleeding during dabigatran treatment is lower than that during warfarin treatment. The characteristics of intracranial hemorrhage during dabigatran therapy, however, remain unclear. METHODS AND RESULTS: The clinical data and treatment summaries of 9 intracranial bleeds that developed during dabigatran treatment in 8 patients with non-valvular atrial fibrillation were retrospectively reviewed. Five patients had small-moderate subdural hematomas, 2 had intracerebral hemorrhage and 1 had traumatic subarachnoid and parenchymal hemorrhage associated with cerebral contusion. Activated partial thromboplastin time upon admission ranged from 31.6 to 72.4s. After admission, systolic blood pressure in the 2 patients with intracerebral hemorrhage was maintained below 140 mmHg, and the subdural hematomas in 4 patients were surgically treated. None of the hematomas became enlarged and outcome was good in most cases. CONCLUSIONS: Hematomas that arise due to acute intracranial bleeding during dabigatran treatment seem to remain small to moderate, hard to expand, and manageable.

Dolichoectatic vertebrobasilar dissecting aneurysm originating from atherosclerosis: an autopsy case.

We herein report an unusual case of profound brain infarction of the posterior circulation due to a dolichoectatic vertebrobasilar dissecting aneurysm (DVDA) originating from atherosclerosis. On autopsy, diffuse atherosclerosis was observed with a multi-fusiform aneurysm measuring 1 to 2 cm in diameter ranging from the left vertebral artery to the basilar artery. The microscopic findings of the aneurysm revealed severe stenosis of the artery caused by intimal thickening, intimal flap formation and thrombosis, indicating the presence of a dissecting aneurysm originating from atherosclerosis. The DVDA observed in this case was considered to be slowly progressive and associated with the development of atherosclerosis. The etiology of structural destabilization in patients with DVDA involves rupture of the internal elastic lamina, which is dislodged by massive hematomas that form atheromatous lesions.

Increase in the Size of an Intracardiac Thrombus during Dabigatran Therapy (110 mg b.i.d.) in an Acute Cardioembolic Stroke Patient.

We report a case of atrial fibrillation in a patient in whom a mobile thrombus in the left atrial appendage increased in size after low-dose dabigatran therapy. A 74-year-old man was admitted to our hospital because of sudden onset of right hemiplasia and dysarthria. On admission, his National Institutes of Health Stroke Scale score was three. Axial diffusion-weighted magnetic resonance images and magnetic resonance angiography images showed hyperintense signals in the left front-parietal cerebral cortex without any intracranial stenotic lesions, and acute cardioembolic stroke associated with nonvalvular atrial fibrillation was diagnosed. Transesophageal echocardiography revealed a mobile thrombosis (1.0 × 2.2 cm) in the left atrial appendage, and dabigatran therapy (110 mg b.i.d.) was initiated to prevent stroke recurrence. Transesophageal echocardiography performed 6 days later revealed that the size of the thrombus had increased to 1.5 × 3.0 cm. Medication was changed to warfarin, and the thrombosis subsequently decreased in size. The patient did not have a recurrent stroke and was discharged with a National Institutes of Health Stroke Scale score of zero. This case demonstrates that low-dose dabigatran may not be effective in reducing the size of a thrombus.

High glycated hemoglobin levels and intracranial artery stenosis are predictive factors for early motor worsening events in patients with penetrating artery infarction.

BACKGROUND: The purpose of this study was to identify typical clinical characteristics to predict early motor worsening (EMW) of patients with penetrating artery infarction. METHODS: We reviewed 65 consecutive patients with pure motor hemiparesis, sensorimotor stroke, and ataxic hemiparesis. EMW was defined as deterioration by ≥1 point on the National Institutes of Health Stroke Scale for motor function within 5 days of admission. RESULTS: EMW was observed in 22 patients (34%). HbA1c levels were higher in patients with EMW than in those without EMW (7.9 ± 2.6 vs. 6.3 ± 1.6%; p < 0.01). The percentage of EMW patients with intracranial artery stenosis (ICAS) was greater than that of non-EMW patients with ICAS (13/22 patients, 59% vs. 8/43 patients, 19%; p < 0.01). Multivariate logistic regression analysis indicated that HbA1c levels ≥7.0% (OR 3.0, 95% CI 1.5-6.8; p < 0.005) or ICAS (OR 2.3, 95% CI 1.2-4.8; p < 0.05) increased the risk of EMW, and the combination of these factors increased the risk in an additive manner (OR 7.6, 95% CI 2.5-40; p < 0.005). CONCLUSION: HbA1c levels ≥7.0% and/or ICAS in patients with penetrating artery infarction are associated with EMW.

Transoral carotid ultrasonography using a micro convex probe with B-flow imaging for extracranial internal carotid artery dissection.

We report on transoral carotid ultrasonography using a micro convex probe with B-flow imaging for determining spontaneous extracranial internal carotid artery dissection just below the petrous portion. A 49-year-old man suffered cortical and subcortical infarction in the region of the right middle cerebral artery. Magnetic resonance angiography on the third day of admission revealed spontaneous recanalization of the right internal carotid artery associated with an intimal flap-like structure at the petrous portion. Transoral carotid ultrasonography using a micro convex probe revealed right extracranial internal carotid artery dissection, showing an increased diameter of the right extracranial internal carotid artery with double lumen formation, stenosis of the true lumen, and a mobile intimal flap in B-flow imaging. Transoral carotid ultrasonography using a micro convex probe was helpful to attempt a self-expanding stent for recanalizing right extracranial internal carotid artery dissection. The patient recovered and was discharged ambulatory. The size of the micro convex probe was optimum for transoral carotid ultrasonography in our patient. Micro convex probe is more commonly used than the standard transoral carotid ultrasonography probe, which lacks versatility. We consider that transoral carotid ultrasonography using a micro convex probe could be routinely used for ultrasonographic evaluation of extracranial internal carotid artery dissection.