The below list represents only planned manuscripts. Some of these
manuscripts have not been received by the Editorial Office yet. Papers
submitted to MDPI journals are subject to peer-review.
Title: Pathogenesis of brain edema and investigations for anti-edema drugs
Authors: Shotaro Michinaga and Yutaka Koyama
Abstract: Brain edema is a potentially fatal pathological state occurred in the early phases of stroke and head trauma. In edematous brain,
excess accumulation of extracellular fluid results in elevation of intracranial pressure leading to impair nerve function. Despite the
seriousness of brain edema, only symptomatic treatments to remove edema fluid are currently available. So, novel medications to prevent
induction of brain edema formations have been required. Pathogenesis of brain edema is classified into vasogenic edema and cytotoxic edema.
Vasogenic edema is defined as that induced by disruption of blood-brain barrier (BBB) and extravasations of serum proteins, which is thought to be a major pathogenesis of brain edema. To investigate mechanisms underlying induction of vasogenic brain edema, cold injury or fluid
percussion injury on animal brains are often used as experimental models. Many factors, including VEGFs, MMPs, chemokines and NO, are
confirmed as inducers of disruption of BBB and brain edema in these model animals. So, inhibitors of these vascular permeability factors are
expected to show anti-edema actions on damaged brain. In this review, we discuss the involvement of vascular permeability factors for brain
edema formation and possibility of anti-edema drugs targeting for these factors.
Title: Magnetoencephalography (MEG) Monitoring Stroke Patients Requiring Early, Intensive and Prolonged Rehabilitation
Author: Stefano Masiero
Abstract: An accurate early diagnosis and prognosis of stroke patients is crucial in order to select those patients which require early, intensive and prolonged rehabilitation, because have greater chances of response. Actually clinical assessment and structural brain scans cannot reliably determine the outcome of the affected people because inter individual variability of connectivity and neuroplasticity mechanisms can influence the evolution of brain damage. How well the brain is connected can be measured using functional magnetic resonance imaging (fMRI) brain scans but also with Electroencephalography/Magnetoencephalography (EEG/MEG). MEG has been experimentally used to detect early modifications in neuroplasticity and connectivity in people with stroke but the methods are not sensitive enough to be used as a clinical diagnostic test.
This review will focus on clinical use of MEG in neurorehabilitation.
Magnetoencephalography (MEG) is a non-invasive neurophysiological technique used to study the cerebral cortex. Currently, MEG is mainly used clinically to localize epileptic foci and eloquent brain areas to avoid damage during neurosurgery. MEG might, however, also be of help in the monitoring of stroke recovery and rehabilitation (Forss et al, 2011; Rossini et al, 2007). Action observation modulates activation of the viewer's motor (Hari et al, 1998) and somatosensory (Avikainen et al., 2002) cortex, with stronger motor-cortex effects for live than video presentation (Järveläinen et al, 2001). Moreover, natural language processing is well accessible with MEG, and it is possible to discriminate between spoken sentences, and suggested speech segmentation in a 200 ms window, even at a syllable level (Luo and Poeppel, 2007). Language production, which is very difficult to study with EEG and fMRI, due to wide-spread artifacts, can be more easily studied with MEG because the resulting signal recording can be better manipulated. MEG can facilitate the exploration of online interaction and communication (Hari and Kujala, 2009).
Measures of functional activity acquired with MEG while hemiplegic patients are either imagining, observing and executing simple movements will have higher accuracy than fMRI activity measures in the selection of good responders to motor rehabilitation. Analysis will focus on Event Related Desinchronizations (ERDS) in the motor/somatosensory cortex. Similarly MEG imaging should give better predictive outcomes in patients with aphasia following speech therapy (either using a cognitive neuropsychological approach or an intensive ecological language treatment). In this case, analysis with focus on Event Related Fields (ERFS) associated with communicative interaction.
To conduct a MEG review in Neurorehabilitation field, is very important because it should generate new data and answer specific performance questions that remain unanswered by the current body of experimental research. In neuromotor and speech rehabilitation there exists few shared method for making decisions on patient treatment duration and intensity.
Title: Advances in Intracranial Pressure Monitoring and its Significance in Managing Traumatic Brain Injury
Authors: Usmah Kawoos, Richard M McCarron and Mikulas Chavko
Abstract: Intracranial pressure (ICP) measurements are fundamental for the evaluation and treatment of many neurological disorders such as subarachnoid hemorrhage, intracerebral hemorrhage, ischemic stroke, and meningitis/encephalitis. In the realm of clinical and non-clinical work, the techniques of ICP monitoring have evolved from being simplistic with certain limitations to slightly complex methods offering advantages over the former methods. Some of the limitations of earlier methods of ICP monitoring include invasive and short-term monitoring, risks of infection and dislodgement of catheter based systems, restricted mobility of the subject etc. Although invasive in nature, ventriculostomy is considered to be the most accurate method of ICP monitoring. Invasive monitoring techniques can be simple in nature; however they demand the availability of some resources like appropriate facilities, trained personnel, critical care support, etc. The invasiveness of ICP measurement limits the frequency with which ICP can be evaluated, hampering the clinical care of patients with ICP disorders. Thus, there has been substantial interest in developing noninvasive methods for the assessment of ICP. Numerous approaches such as tympanic membrane displacement (TMD), optic nerve sheath diameter, fundoscopy, transcranial Doppler, near-infra red spectroscopy (NIRS), have been applied to the problem, although none seems to represent a complete solution because of their accuracy.
ICP measurements are fundamental in the present protocols for intensive care of patients during the acute stage of severe traumatic brain injury (TBI). TBI results in activation of primary and secondary pathophysiological processes which have an effect on ICP. In severe cases of TBI, elevated ICP is associated with mortality or poor clinical outcome. The main goal of ICP monitoring in TBI is to allow early detection of secondary damage and initiate immediate therapeutic intervention. The long-term continuous ICP monitoring is even beneficial as the pattern of changes in ICP can be used as a guide for individualized treatment. ICP monitoring in conjunction with other neurological monitoring can help in understanding the pathophysiological processes of the damage.
This review article presents, a) an overview of the significance of ICP monitoring, b) different ICP monitoring methods such as various invasive and non-invasive techniques and advantages and disadvantages of the techniques, and c) the role of ICP monitoring in brain damage, especially in the management of TBI.
Keywords: Intracranial pressure, invasive methods, non-invasive methods, telemetry, traumatic brain injury.
Title: Evaluation of injured axons using two-photon excited fluorescence microscopy after spinal cord contusion injury in EYFP H-line mice
Author: Yusuke Oshima
Abstract: Elucidation of degeneration processes of injured axons is important for developing therapeutic modules for the treatment of spinal cord injuries. The aim of this study is to establish time-lapse observation method of injured axons in the same living animals after spinal cord contusion injury. YFP-H transgenic mice, we used in this study, express fluorescence in their nerve fibers. Contusion damage to the spinal cord at 11th vertebra was performed by IH impactor which applied pressure of 50 kdyn. The damaged spinal cords were re-exposed at the observation period under anesthesia and were observed by two-photon excited fluorescence microscopy, which can observe deep portion of tissues including axons in spinal codes. No significant morphological change of injured axons was observed immediately after injury. At 3 days after injury, the number of axons decreased and residual axons were fragmented. At 7 days after injury, only fragments existed in the damaged tissue. No hind limb movement was observed during the observation period after spinal cord injury. In spite of the immediate paresis of hind-limbs after the contusion injury, the morphological degeneration of injured axon was delayed. This means that there is possible effective therapeutic period before the irreversible axon degeneration after spinal cord injury.
Title: Perturbation of brain oscillations after ischemic stroke: a potential biomarker for post stroke function and therapeutic efficacy
Authors: Gratianne Rabiller, Ji-wei He1 and Jialing Liu
Abstract: Brain waves resonate from the generators of electrical current and propagate across brain regions with oscillation frequencies ranging from 0.05 to 500 Hz. These oscillatory waves recorded by electroencephalogram (EEG) can be grouped into five main categories according to their frequencies, namely delta (1.5-4Hz), theta (4-8 Hz), alpha (8-12 Hz), beta (12-30 Hz) and gamma (30-80 Hz). Emerging evidences from experimental and human studies suggest that specific function and behaviors seem to be associated with the presence of each oscillation band, although the complex relationship between oscillation frequency and function, as well as the interaction between brain oscillations are far from being clear. Changes of brain oscillation patterns have long been implicated in the diseases of the central nervous system including ischemic stroke, in which the reduction of cerebral blood flow as well as the progression of tissue damage have direct spatiotemporal effects on the power of several oscillatory bands and their interactions. This review summarizes the current knowledge in behavior and function associated with each brain oscillations, and specific changes of which corresponding to the molecular events and functional alterations observed after experimental and human stroke. We provide the basis of the generations of brain oscillations and potential cellular and molecular mechanisms underlying stroke-induced perturbation. We also discussed the implication of using EEG patterns as biomarkers for the prediction of stroke outcome and therapeutic efficacy.
Keywords: EEG, ischemia, MCAO, CBF