Neurotransmitters and motor activity: effects on functional recovery after brain injury

Frequency Specific Optogenetic Stimulation of the Locus Coeruleus Induces Task-Relevant Plasticity in the Motor Cortex

The locus ceruleus (LC) is the primary source of neocortical noradrenaline, which is known to be involved in diverse brain functions including sensory perception, attention, and learning. Previous studies have shown that LC stimulation paired with sensory experience can induce task-dependent plasticity in the sensory neocortex and in the hippocampus. However, it remains unknown whether LC activation similarly impacts neural representations in the agranular motor cortical regions that are responsible for movement planning and production. In this study, we test whether optogenetic stimulation of the LC paired with motor performance is sufficient to induce task-relevant plasticity in the somatotopic cortical motor map. Male and female TH-Cre + rats were trained on a skilled reaching lever-pressing task emphasizing the use of the proximal forelimb musculature, and a viral approach was used to selectively express ChR2 in noradrenergic LC neurons. Once animals reached criterial behavioral performance, they received five training sessions in which correct task performance was paired with optogenetic stimulation of the LC delivered at 3, 10, or 30 Hz. After the last stimulation session, motor cortical mapping was performed using intracortical microstimulation. Our results show that lever pressing paired with LC stimulation at 10 Hz, but not at 3 or 30 Hz, drove the expansion of the motor map representation of the task-relevant proximal FL musculature. These findings demonstrate that phasic, training-paired activation of the LC is sufficient to induce experience-dependent plasticity in the agranular motor cortex and that this LC-driven plasticity is highly dependent on the temporal dynamics of LC activation.

The Schwann cell-specific G-protein Gαo (Gnao1) is a cell-intrinsic controller contributing to the regulation of myelination in peripheral nerve system

Myelin sheath abnormality is the cause of various neurodegenerative diseases (NDDs). G-proteins and their coupled receptors (GPCRs) play the important roles in myelination. Gnao1, encoding the major Gα protein (Gαo) in mammalian nerve system, is required for normal motor function. Here, we show that Gnao1 restricted to Schwann cell (SCs) lineage, but not neurons, negatively regulate SC differentiation, myelination, as well as re-myelination in peripheral nervous system (PNS). Mice lacking Gnao1 expression in SCs exhibit faster re-myelination and motor function recovery after nerve injury. Conversely, mice with Gnao1 overexpression in SCs display the insufficient myelinating capacity and delayed re-myelination. In vitro, Gnao1 deletion in SCs promotes SC differentiation. We found that Gnao1 knockdown in SCs resulting in the elevation of cAMP content and the activation of PI3K/AKT pathway, both associated with SC differentiation. The analysis of RNA sequencing data further evidenced that Gnao1 deletion cause the increased expression of myelin-related molecules and activation of regulatory pathways. Taken together, our data indicate that Gnao1 negatively regulated SC differentiation by reducing cAMP level and inhibiting PI3K-AKT cascade activation, identifying a novel drug target for the treatment of demyelinating diseases.

Stroke and cognitive impairment: understanding the connection and managing symptoms

Stroke is a leading cause of long-term disability worldwide, and cognitive impairment is a common consequence of stroke. Understanding the connection between stroke and cognitive impairment is crucial for effectively managing symptoms and improving patients' quality of life. This abstract provides an overview of the relationship between stroke and cognitive impairment and explores strategies for managing cognitive symptoms in stroke survivors. A comprehensive review of relevant literature was conducted to examine the association between stroke and cognitive impairment. Various factors contributing to cognitive impairment after stroke were explored, including the location and severity of the stroke, vascular risk factors, and underlying mechanisms. Evidence-based strategies for managing cognitive symptoms in stroke survivors were also analyzed, such as cognitive rehabilitation, pharmacological interventions, and lifestyle modifications. The review revealed a strong link between stroke and cognitive impairment. The location and severity of the stroke play a significant role in determining the specific cognitive deficits experienced by individuals. Vascular risk factors, including hypertension, diabetes, and atrial fibrillation, contribute to cognitive decline after stroke. Mechanisms such as cerebral hypoperfusion, white matter damage, and neuroinflammation also play a role. Cognitive rehabilitation programs have shown promising results in improving cognitive function, while certain medications may help manage specific cognitive symptoms. Lifestyle modifications like physical exercise and a healthy diet have been associated with better cognitive outcomes in stroke survivors.

Glutamate, Glutamine, GABA and Oxidative Products in the Pons Following Cortical Injury and Their Role in Motor Functional Recovery

Brain injury leads to an excitatory phase followed by an inhibitory phase in the brain. The clinical sequelae caused by cerebral injury seem to be a response to remote functional inhibition of cerebral nuclei located far from the motor cortex but anatomically related to the injury site. It appears that such functional inhibition is mediated by an increase in lipid peroxidation (LP). To test this hypothesis, we report data from 80 rats that were allocated to the following groups: the sham group (n = 40), in which rats received an intracortical infusion of artificial cerebrospinal fluid (CSF); the injury group (n = 20), in which rats received CSF containing ferrous chloride (FeCl₂, 50 mM); and the recovery group (n = 20), in which rats were injured and allowed to recover. Beam-walking, sensorimotor and spontaneous motor activity tests were performed to evaluate motor performance after injury. Lipid fluorescent products (LFPs) were measured in the pons. The total pontine contents of glutamate (GLU), glutamine (GLN) and gamma-aminobutyric acid (GABA) were also measured. In injured rats, the motor deficits, LFPs and total GABA and GLN contents in the pons were increased, while the GLU level was decreased. In contrast, in recovering rats, none of the studied variables were significantly different from those in sham rats. Thus, motor impairment after cortical injury seems to be mediated by an inhibitory pontine response, and functional recovery may result from a pontine restoration of the GLN-GLU-GABA cycle, while LP may be a primary mechanism leading to remote pontine inhibition after cortical injury.

Olfactory Stimulation Successfully Improves Swallowing Function of Aged Rats through Activating Central Neuronal Networks and Downstream DHPR-RyR-mediated Neuromuscular Activities

Presbyphagia is age-related changes in swallowing function, which imposes a high risk of aspiration in older adults. Considering olfactory stimulation (OS) can influence behavioral activities by modulating neuronal excitability, the present study aims to determine whether OS could improve the swallowing function of aged rats through activating the central neuronal networks and downstream muscular activities participated in the control of swallowing. Aged male Wistar rats received OS by inhaling a mixture of plant-based volatile molecules twice a day for 12 days were subjected to functional magnetic resonance imaging (fMRI) and c-fos, choline acetyltransferase (ChAT) immunostaining to detect the neuronal activities of the orbitofrontal cortex (OFC) and medullary nuclei engaged in swallowing control, respectively. The functional effects of OS on downstream pharyngeal muscle activity were examined by evaluating the dihydropyridine receptor-ryanodine receptor (DHPR-RyR) mediated intra-muscular Ca2 + expression, and analyzing the amplitude/frequency of muscle contraction, respectively. In untreated rats, only moderate signal of fMRI and mild c-fos/ChAT expression was detected in the OFC and medullary nuclei, respectively. However, following OS, intense signals of fMRI and immunostaining were clearly expressed in the orbitofronto-medullary networks. Functional data corresponded well with above findings in which OS significantly enhanced DHPR-RyR-mediated intra-muscular Ca2 + expression, effectively facilitated a larger amplitude of pharyngeal muscle contraction, and exhibited better performance in consuming larger amounts of daily dietary. As OS successfully activates the neuromuscular activities participated in the control of swallowing, applying OS may serve as an effective, easy, and safe strategy to greatly improve the swallow function of aging populations.

Effects of Preexisting Psychotropic Medication Use on a Cohort of Patients with Ischemic Stroke Outcome

BACKGROUND

Several studies investigated the use of selective serotonin reuptake inhibitors (SSRI) after ischemic stroke to improve motor recovery. However, little is known about the effects of preexisting psychotropic medication use (PPMU), such as antidepressants, on a long-term ischemic stroke functional disability.

OBJECTIVE

We sought to determine the prevalence of PPMU and whether PPMU relates to the long-term clinical outcome in a cohort of patients presenting with acute ischemic strokes.

METHODS

We retrospectively analyzed 323 consecutive patients who presented with an acute ischemic stroke in a single institution between January 2015 and December 2017. Baseline characteristics, functional disability as measured by the modified Rankin Scale (mRS), and major adverse cardiovascular complications (MACE) within 365 days were recorded. The comparison groups included a control group of ischemic stroke patients who were not on psychotropic medications before and after the index ischemic stroke and a second group of poststroke psychotropic medication use (PoMU), which consisted of patients started on psychotropic medication during the index admission.

RESULTS

The prevalence of PPMU in the studied cohort was 21.4% (69/323). There was a greater proportion of females in the PPMU than in the comparison groups (P < 0.001), while vascular risk factors were similar in all groups, except for an increased presence of posterior circulation infarcts in the PPMU (37.4% vs. 18.8%, P < 0.001). Among the patients with available 1-year follow-up data (n = 246), we noted significantly greater improvement in stroke deficits, measured by National Institute of Health Stroke Scale (NIHSS) between PPMU and PoMU vs. control (3 (0-7) versus 1 (0-4), P = 0.041). The 1-year mRS was worse in PPMU and PoMU compared to the control group (2 (IQ 1-3) vs. 2 (IQ 0-3) vs. 1 (IQ 0-2), respectively, P = 0.013), but delta mRS reflecting the degree of mRS improvement showed no significant difference between any PMU and control patients (P = 0.76). There was no statistically significant difference in MACE.

CONCLUSION

PPMU in ischemic stroke is common; it can be beneficial in ischemic stroke in the long-term clinical outcome and is not associated with increased risks of MACE.

The Implications of Motor and Cognitive Inhibition for Hot and Cool Executive Functions: The Case of Quadrato Motor Training

Enabling the ceasing of ongoing or prepotent responses and the controlling of interference, motor inhibition facilitates the development of executive functions (EFs) such as thought before action, decision-making, self-regulation of affect, motivation, and arousal. In the current paper, a characterization is offered of the relationship between motor inhibition and the executive functioning system, in the context of a proposed division into predominantly affective (hot) and cognitive (cool) components corresponding to neural trajectories originating in the prefrontal cortex. This division is central to understanding the effects of a specifically-structured sensorimotor movement training practice, known as Quadrato Motor Training (QMT), on hot and cool EFs. QMT's effects on crucial mechanisms of integrating different EF components are discussed.

Impacts of Sleep Loss versus Waking Experience on Brain Plasticity: Parallel or Orthogonal?

Recent studies on the effects of sleep deprivation on synaptic plasticity have yielded discrepant results. Sleep deprivation studies using novelty exposure as a means to keep animals awake suggests that sleep (compared with wake) leads to widespread reductions in net synaptic strength. By contrast, sleep deprivation studies using approaches avoiding novelty-induced arousal (i.e., gentle handling) suggest that sleep can promote synaptic growth and strengthening. How can these discrepant findings be reconciled? Here, we discuss how varying methodologies for the experimental disruption of sleep (with differential introduction of novel experiences) could fundamentally alter the experimental outcome with regard to synaptic plasticity. Thus, data from experiments aimed at assessing the relative impact of sleep versus wake on the brain may instead reflect the quality of the waking experience itself. The highlighted work suggests that brain plasticity resulting from novel experiences versus wake per se has unique and distinct features.

Effect of Dextroamphetamine on Poststroke Motor Recovery: A Randomized Clinical Trial

Importance

Data from animal models show that the administration of dextroamphetamine combined with task-relevant training facilitates recovery after focal brain injury. Results of clinical trials in patients with stroke have been inconsistent.

Objectives

To collect data important for future studies evaluating the effect of dextroamphetamine combined with physiotherapy for improving poststroke motor recovery and to test the efficacy of the approach.

Design, Setting, Participants

This pilot, double-blind, block-randomized clinical trial included patients with cortical or subcortical ischemic stroke and moderate or severe motor deficits from 5 rehabilitation hospitals or units. Participants were screened and enrolled from March 2001 through March 2003. The primary outcome was assessed 3 months after stroke. Study analysis was completed December 31, 2015. A total of 1665 potential participants were screened and 64 were randomized. Participants had to begin treatment 10 to 30 days after ischemic stroke. Data analysis was based on intention to treat.

Interventions

Participants were allocated to a regimen of 10 mg of dextroamphetamine (n = 32) or placebo (n = 32) combined with a 1-hour physical therapy session beginning 1 hour after drug or placebo administration every 4 days for 6 sessions in addition to standard rehabilitation.

Main Outcomes and Measures

The primary outcome was the difference between groups in change in Fugl-Meyer motor scores from baseline to 3 months after stroke (intention to treat with dextroamphetamine). Secondary exploratory measures included the National Institutes of Health Stroke Scale, Canadian Neurological Scale, Action Research Arm Test, modified Rankin Scale score, Functional Independence Measure, Ambulation Speed and Distance, Mini-Mental State Examination, Beck Depression Inventory, and Stroke Impact Scale.

Results

Among the 64 patients randomized to dextroamphetamine vs placebo (55% men; median age, 66 years; age range, 27-91 years), no overall treatment-associated difference in the mean (SEM) change in Fugl-Meyer motor scores from baseline to 3 months after stroke was noted (-18.65 [2.27] points with dextroamphetamine vs -20.83 [2.94] points with placebo; P = .58). No overall treatment-associated differences in any of the study's secondary measures and no differences in subgroups based on stroke location or baseline severity were found. No adverse events were attributed to study treatments.

Conclusions and Relevance

Treatment with dextroamphetamine combined with physical therapy did not improve recovery of motor function compared with placebo combined with physical therapy as assessed 3 months after hemispheric ischemic stroke. The studied treatment regimen was safe.

Trial Registration

ClinicalTrials.gov identifier: NCT01905371.

Duration of Agitation, Fluctuations of Consciousness, and Associations with Outcome in Patients with Subarachnoid Hemorrhage

BACKGROUND

Agitation is common after subarachnoid hemorrhage (SAH) and may be independently associated with outcomes. We sought to determine whether the duration of agitation and fluctuating consciousness were also associated with outcomes in patients with SAH.

METHODS

We identified all patients with positive Richmond Agitation Sedation Scale (RASS) scores from a prospective observational cohort of patients with SAH from 2011 to 2015. Total duration of agitation was extrapolated for each patient using available RASS scores, and 24-h mean and standard deviation (SD) of RASS scores were calculated for each patient. We also calculated each patient's duration of substantial fluctuation of consciousness, defined as the number of days with 24-h RASS SD > 1. Patients were stratified by 3-month outcome using the modified Rankin scale, and associations with outcome were assessed via logistic regression.

RESULTS

There were 98 patients with at least one positive RASS score, with median total duration of agitation 8 h (interquartile range [IQR] 4-18), and median duration of substantially fluctuating consciousness 2 days (IQR 1-3). Unfavorable 3-month outcome was significantly associated with a longer duration of fluctuating consciousness (odds ratio [OR] per day, 1.51; 95% confidence interval [CI], 1.04-2.20; p = 0.031), but a briefer duration of agitation (OR per hour, 0.94; 95% CI, 0.89-0.99; p = 0.031).

CONCLUSION

Though a longer duration of fluctuating consciousness was associated with worse outcomes in our cohort, total duration of agitation was not, and may have had the opposite effect. Our findings should therefore challenge the intensity with which agitation is often treated in SAH patients.

A mechanistic review on GNAO1-associated movement disorder

Mutations in the GNAO1 gene cause a complex constellation of neurological disorders including epilepsy, developmental delay, and movement disorders. GNAO1 encodes Gα_o, the α subunit of G_o, a member of the G_i/o family of heterotrimeric G protein signal transducers. G_o is the most abundant membrane protein in the mammalian central nervous system and plays major roles in synaptic neurotransmission and neurodevelopment. GNAO1 mutations were first reported in early infantile epileptic encephalopathy 17 (EIEE17) but are also associated with a more common syndrome termed neurodevelopmental disorder with involuntary movements (NEDIM). Here we review a mechanistic model in which loss-of-function (LOF) GNAO1 alleles cause epilepsy and gain-of-function (GOF) alleles are primarily associated with movement disorders. We also develop a signaling framework related to cyclic AMP (cAMP), synaptic vesicle release, and neural development and discuss gene mutations perturbing those mechanisms in a range of genetic movement disorders. Finally, we analyze clinical reports of patients carrying GNAO1 mutations with respect to their symptom onset and discuss pharmacological/surgical treatments in the context of our mechanistic model.

Noradrenergic-Dopaminergic Interactions Due to DSP-4-MPTP Neurotoxin Treatments: Iron Connection

The investigations of noradrenergic lesions and dopaminergic lesions have established particular profiles of functional deficits and accompanying alterations of biomarkers in brain regions and circuits. In the present account, the focus of these lesions is directed toward the effects upon dopaminergic neurotransmission and expression that are associated with the movement disorders and psychosis-like behavior. In this context, it was established that noradrenergic denervation, through administration of the selective noradrenaline (NA) neurotoxin, DSP-4, should be performed prior to the depletion of dopamine (DA) with the selective neurotoxin, MPTP. Employing this regime, it was shown that (i) following DSP-4 (50 mg/kg) pretreatment of C57/Bl6 mice, both the functional and neurochemical (DA loss) effects of MPTP (2 × 20 and 2 × 40 mg/kg) were markedly exacerbated, and (ii) following postnatal iron (Fe(2+), 7.5 mg/kg, on postnatal days 19-12), pretreatment with DSP-4 followed by the lower 2 × 20 mg/kg MPTP dose induced even greater losses of motor behavior and striatal DA. As yet, the combination of NA-DA depletions, and even more so Fe(2+)-NA-DA depletion, has been considered to present a movement disorder aspect although studies exploring cognitive domains are lacking. With intrusion of iron overload into this formula, the likelihood of neuropsychiatric disorder, as well, unfolds.

Neurobiological consequences of traumatic brain injury

Traumatic brain injury (TBI) is a worldwide public health problem typically caused by contact and inertial forces acting on the brain. Recent attention has also focused on the mechanisms of injury associated with exposure to blast events or explosions. Advances in the understanding of the neuropathophysiology of TBI suggest that these forces initiate an elaborate and complex array of cellular and subcellular events related to alterations in Ca⁺⁺ homeostasis and signaling. Furthermore, there is a fairly predictable profile of brain regions that are impacted by neurotrauma and the related events. This profile of brain damage accurately predicts the acute and chronic sequelae that TBI survivors suffer from, although there is enough variation to suggest that individual differences such as genetic polymorphisms and factors governing resiliency play a role in modulating outcome. This paper reviews our current understanding of the neuropathophysiology of TBI and how this relates to the common clinical presentation of neurobehavioral difficulties seen after an injury.

Human clinical trails in antiepileptogenesis

Blocking the development of epilepsy (epileptogenesis) is a fundamental research area with the potential to provide large benefits to patients by avoiding the medical and social consequences that occur with epilepsy and lifelong therapy. Human clinical trials attempting to prevent epilepsy (antiepileptogenesis) have been few and universally unsuccessful to date. In this article, we review data about possible pathophysiological mechanisms underlying epileptogenesis, discuss potential interventions, and summarize prior antiepileptogenesis trials. Elements of ideal trials designs for successful antiepileptogenic intervention are suggested.

Recovery of motor deficit, cerebellar serotonin and lipid peroxidation levels in the cortex of injured rats

The sensorimotor cortex and the cerebellum are interconnected by the corticopontocerebellar (CPC) pathway and by neuronal groups such as the serotonergic system. Our aims were to determine the levels of cerebellar serotonin (5-HT) and lipid peroxidation (LP) after cortical iron injection and to analyze the motor function produced by the injury. Rats were divided into the following three groups: control, injured and recovering. Motor function was evaluated using the beam-walking test as an assessment of overall locomotor function and the footprint test as an assessment of gait. We also determined the levels of 5-HT and LP two and twenty days post-lesion. We found an increase in cerebellar 5-HT and a concomitant increase in LP in the pons and cerebellum of injured rats, which correlated with their motor deficits. Recovering rats showed normal 5-HT and LP levels. The increase of 5-HT in injured rats could be a result of serotonergic axonal injury after cortical iron injection. The LP and motor deficits could be due to impairments in neuronal connectivity affecting the corticospinal and CPC tracts and dysmetric stride could be indicative of an ataxic gait that involves the cerebellum.

Long-term motor improvement after stroke is enhanced by short-term treatment with the alpha-2 antagonist, atipamezole

Drugs that increase central noradrenergic activity have been shown to enhance the rate of recovery of motor function in pre-clinical models of brain damage. Less is known about whether noradrenergic agents can improve the extent of motor recovery and whether such improvement can be sustained over time. This study was designed to determine if increasing central noradrenergic tone using atipamezole, an alpha-2 adrenoceptor antagonist, could induce a long-term improvement in motor performance in rats subjected to ischemic brain damage caused by permanent middle cerebral artery occlusion. The importance of pairing physical "rehabilitation" with enhanced noradrenergic activity was also investigated. Atipamezole (1 mg/kg, s.c.) or vehicle (sterile saline) was administered once daily on Days 2-8 post-operatively. Half of each drug group was housed under enriched environment conditions supplemented with daily focused activity sessions while the other half received standard housing with no focused activity. Skilled motor performance in forelimb reaching and ladder rung walking was assessed for 8 weeks post-operatively. Animals receiving atipamezole plus rehabilitation exhibited significantly greater motor improvement in both behavioral tests as compared to vehicle-treated animals receiving rehabilitation. Interestingly, animals receiving atipamezole without rehabilitation exhibited a significant motor improvement in the ladder rung walk test but not the forelimb reaching test. These results suggest that a short-term increase in noradrenergic activity can lead to sustained motor improvement following stroke, especially when paired with rehabilitation.

The 2009 Feinberg lecture: the continuum of stroke research and policy

BACKGROUND AND PURPOSE

This annual Feinberg Award lecture is intended to present examples of the broad scope of stroke-related research and to show how different investigative approaches can advance the field to improve stroke patient's outcomes. In keeping with one of the objectives of the American Heart/American Stroke Association, this lecture also provides a perspective and highlights opportunities for beginning clinical investigators. Summary of Report- Clinically, the continuum of stroke research and care can be divided into primary prevention, acute interventions, secondary prevention, and poststroke recovery. From a technical/methodological standpoint, fundamental laboratory studies yield insights into basic disease mechanisms and applied laboratory studies further explore the biological basis of disease and evaluate possible therapeutic interventions. The results of these laboratory-based observations can inform clinical study design whereas questions raised by clinical observations can be explored in laboratory experiments (ie, "translational" research). Additional information is gained through observational, interventional, and synthetic (eg, meta-analytic) clinical studies. Outcomes/effectiveness research determines how well interventions perform in different "real-world" settings. The discussion provides examples of how several of these approaches can be used to address various research questions. The importance for stroke investigators to contribute to related public policy issues is also reviewed.

CONCLUSIONS

This is an exciting era for clinical investigators studying stroke and for those at the beginning stages of their careers. Whether taking a broad-based research approach or working on a specific, focused question, our combined efforts are leading to improved outcomes for patients with stroke, the very goal of Bill Feinberg's career.

Motor recovery and axonal plasticity with short-term amphetamine after stroke

BACKGROUND AND PURPOSE

There is considerable debate regarding the efficacy of amphetamine to facilitate motor recovery after stroke or experimental brain injury. Different drug dosing and timing schedules and differing physical rehabilitation strategies may contribute to outcome variability. The present study was designed to ascertain (1) whether short-term amphetamine could induce long-term functional motor recovery in rats after an ischemic lesion modeling stroke in humans; (2) how different levels of physical rehabilitation interact with amphetamine to enhance forelimb-related functional outcome; and (3) whether motor improvement was associated with axonal sprouting from intact corticoefferent pathways originating in the contralesional forelimb motor cortex.

METHODS

After permanent middle cerebral artery occlusion, rats received vehicle or amphetamine during the first postoperative week (2 mg/kg, subcutaneously on Postoperative Days 2, 5, and 8). In both treatment groups, separate cohorts of rats were exposed to different levels of "physical rehabilitation" represented by a control environment, enriched environment, or enriched environment with additional sessions of focused activity. Skilled forelimb performance was assessed using the forelimb reaching task and ladder rung walk test. Anterograde tracing with biotinylated dextran amine was used to assess new fiber outgrowth to denervated motor areas.

RESULTS

All treatment groups showed significant motor improvement as compared with control-housed, vehicle-treated animals. However, animals housed in an enriched environment that received amphetamine paired with focused activity sessions performed significantly better than any other treatment group and was the only group to achieve complete motor recovery (ie, reached preoperative performance) by 8 weeks. This recovery was associated with axonal sprouting into deafferentated subcortical areas from contralesional projection neurons.

CONCLUSIONS

This study suggests that, after stroke, short-term pairing of amphetamine with sufficiently focused activity is an effective means of inducing long-term improvement in forelimb motor function. The anatomic data suggests that corticoefferent plasticity in the form of axonal sprouting contributes to the maintenance of motor recovery.

Neurobehavioral management of traumatic brain injury in the critical care setting

Traumatic brain injury (TBI) results in approximately 230,000 hospitalizations annually in the United States. Advances in the acute management of TBI have improved survival after TBI. Many TBI survivors develop neurobehavioral disturbances in the acute post-injury period. Neurobehavioral sequelae present clinical management challenges for critical care professionals. This article defines and describes TBI and reviews its common neuroanatomic and neurobehavioral consequences. These disturbances are organized under the framework of posttraumatic encephalopathy, and the characteristic forms and stages of recovery of this condition are discussed. Recommendations regarding evaluation and management of posttraumatic neurobehavioral problems in the critical care setting are offered.

The stroke rehabilitation paradigm

The matrix of stroke rehabilitation is evolving as we look outside the box of traditional therapy type, timing, and intensity of rehabilitation techniques. For inpatient wards, the goal of medical stability and prompt resolution of complications to maximize participation in therapy remains paramount. In the current medical model, we focus on teaching compensatory strategies and rarely on restorative approaches because of time and financial limitations. Researchers aim to identify new technologic and molecular approaches to improve functional outcomes and more accurately predict disability. This article examines different concepts surrounding the comprehensive rehabilitation paradigm of stroke survivors.