摘要:

Ultrasound‐derived volumetric flow analysis may be useful in answering questions of basic physiological interest in the cerebrovascular circulation. Using this technique, the authors have sought to describe quantitatively the complete concurrent flow relations among all four arteries supplying the brain. The aim of this study of normal subjects was to determine the relative flow contributions of the antenor (internal carotid arteries) and posterior (vertebral arteries) cerebral circulation. Comparisons between the observed and theoretically expected anterior and posterior flow distribution would provide an opportunity to assess traditional rheological conceptions in vivo. Pulsed color Doppler ultrasonography was used to measure mean flow rates in the internal carotid and vertebral arteries in 21 normal adults. The anterior circulation (Internal carotid arteries bilaterally) carried 82% of the brain's blood supply and compnsed 67% of the total vascular cross‐sectional area. These values demonstrate precise concordance between observations in vivo and the theoretically derived (Hagen‐Poiseuille) expected flow distribution. These cerebrovascular findings support the traditional conception of macroscopic blood flow. Further studies using ultrasound‐derived volumetric analysis of the brain's arterial flow relations may illuminate the vascular pathophysiology underlying aging, cerebral ischemia, and dementias.

ISSN:1051-2284    

DOI:10.1111/jon1995511

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

Late‐onset GM, gangliosidosis, a rare inherited neuronal storage disease, is characterized by a vanety of clinical manifestations. The common clinical picture comprises neuromuscular, spinocerebellar, extrapyramidal, cognitive, and psychiatric abnormalities. Details of the extent of muscle involvement have never been reported. Eight patients with this syndrome were evaluated for the existence and extent of motor neuron disease using routine electrodiagnosis and systematic evaluation of skeletal musculature by computed tomography. Motor neuron disease was present in each and every patient regardless of the clmical manifestations and to a degree beyond that suspected on neurological examination. Muscle imaging disclosed a diffuse wasting and fatty replacement of muscles with predilection of pelvic and thigh muscles, and especially the quadriceps group. It seems that progressive motor disability in this syndrome IS mainly due to motor neuron disease, as manifested by muscle atrophy, which can be easily demonstrated by muscle computed tomography.

ISSN:1051-2284    

DOI:10.1111/jon1995514

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

The diagnosis of acute Guillain‐Barre syndrome and chronic inflammatory demyelinating polyradiculoneuropathy is based on clinical characteristics, abnormalities on nerve conduction studies, and nerve biopsy specimens indicating demyelination. Inflammation and edema are also common findings in nerve specimens Immunotherapy is helpful in these dysimmune conditions. Occasionally the diagnosis is difficult to make, particularly when electrophysiological testing or nerve biopsy findings are not characteristic. The authors found contrast enhancement of lumbosacral roots in patients with chronic inflammatory demyelinating polyradiculoneuropathy and Guillain‐Barre syndrome, but not m those with other demyelinating neuropathies. Contrast‐enhanced magnetic resonance imaging could be a useful tool in the diagnosis of the dysimmune inflammatory neuropathies.

ISSN:1051-2284    

DOI:10.1111/jon1995519

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

The purpose of this study was to compare the effects of critical neck angulation (rotation and hyperextension) on vertebral artery perfusion in symptomatic and control populations and to determine whether this represents a risk factor for ischemic stroke.

ISSN:1051-2284    

DOI:10.1111/jon19955116

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

Complex changes in the appearance of blood on magnetic resonance images (MRis) complicate interpretation of intracerebral hemorrhage. In this study senal MRIs of intracerebral hemorrhage were obta1ned at 1. 5 T, using a recently developed model for brain hemorrhage, and the MRI findings were compared with histological findings. Hemorrhages were mduced in 24 adult rats by the stereotactic injection of 0.5 unit of bactenal collagenase into the caudate/putamen. Initially, there was hypointensity seen on both T1‐ and T2‐weighted images. Conversion to hyperintensity began on both T1‐ and T2‐weighted images around 10 hours, when red blood cell lysis was observed histologically. By 24 hours, complete conversion to marked hyperintensity had occurred. Calculated T2 values increased twofold to fivefold after lysis, indicating that T2 effects dominate the convers1on to hyper‐intensity seen after red blood cell lysis. At 24 hours there was a rim of intact red blood cells around the lesion, which was hypointense on MRI at a time when iron stains were negative. Fresh blood appears hypointense on T1‐ and T2‐weighted images both at the early stages of a bleed and at later stages when rebleeding occurs. Collagenase‐induced hemorrhage is a useful animal model to follow the evolution of paramagnetic effects of blood on MRI.

ISSN:1051-2284    

DOI:10.1111/jon19955123

出版商:Wiley    

年代:2016

数据来源: WILEY

ISSN:1051-2284    

DOI:10.1111/jon19955134

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

New developments in multimodal registration of electroencephalography (EEG), magnetic resonance imaging (MRI), and pOSitron emission tomography (PET) are presented as a method to create a tomographic EEG. Three‐dimensional information about the x,y,z location of the sources of event‐related potentials is corroborated through the use of experimental design and coregistration with MRI and PET. Once the three‐dimension allocation of event‐related potential dipole sources IS identified and corroborated, pseudoinverse procedures are used to derive a new EEG voltage sequence from each of the dipoles Each denved EEG dipole time series is analogous to recording EEG from a deeply implanted electrode and constitutes a four‐dimensional tomographic EEG (ie, three‐dimensional space plus time) EEG coherence and phase analyses are then performed on the dipole‐derived time series to study the temporal and spatial dynamics of neural network switching during voluntary finger movements. The purpose of this article is to demonstrate a new method to exploit the time domain dynamics of neural network switching in behaving human subjects.

ISSN:1051-2284    

DOI:10.1111/jon19955135

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

A case of ankylosing spondylitis associated with massive dural ectasia is presented. Computed tomography and magnetic resonance imaging characteristics are shown, and possible causes are discussed.

ISSN:1051-2284    

DOI:10.1111/jon19955146

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

In a nonimmunocompromised patient with cerebral cryptococcosis, unique magnetic resonance findings included abnormalities limited to the posterior fossa and cerebellar hemispheric edema, gyriform enhancement of the vermis and cerebellar hemispheres, and infratentorial plaquelike enhancement. Magnetic resonance findings in central nervous system cryptococcosis are discussed.

ISSN:1051-2284    

DOI:10.1111/jon19955148

出版商:Wiley    

年代:2016

数据来源: WILEY

ISSN:1051-2284    

DOI:10.1111/jon19955150

出版商:Wiley    

年代:2016

数据来源: WILEY