Learning, not adaptation, characterizes stroke motor recovery: evidence from kinematic changes induced by robot-assisted therapy in trained and untrained task in the same workspace.

Both the American Heart Association and the VA/DoD endorse upper-extremity robot-mediated rehabilitation therapy for stroke care. However, we do not know yet how to optimize therapy for a particular patient's needs. Here, we explore whether we must train patients for each functional task that they must perform during their activities of daily living or alternatively capacitate patients to perform a class of tasks and have therapists assist them later in translating the observed gains into activities of daily living. The former implies that motor adaptation is a better model for motor recovery. The latter implies that motor learning (which allows for generalization) is a better model for motor recovery. We quantified trained and untrained movements performed by 158 recovering stroke patients via 13 metrics, including movement smoothness and submovements. Improvements were observed both in trained and untrained movements suggesting that generalization occurred. Our findings suggest that, as motor recovery progresses, an internal representation of the task is rebuilt by the brain in a process that better resembles motor learning than motor adaptation. Our findings highlight possible improvements for therapeutic algorithms design, suggesting sparse-activity-set training should suffice over exhaustive sets of task specific training.

Quality improvement in neurology: AAN epilepsy quality measures: Report of the Quality Measurement and Reporting Subcommittee of the American Academy of Neurology.

OBJECTIVE: Epilepsy is a common neurologic condition with significant personal, societal, medical, and economic burdens. There are considerable gaps in the quality of care delivered. Measuring the quality of care delivered is the first step to its improvement. Performance measures are easily identified and quantitated ways to assess whether specific activities were carried out during a patient encounter. Therefore, epilepsy performance measures were derived through a standardized systematic process and may be the basis for pay-for-performance initiatives and maintenance of certification requirements. METHODS: Epilepsy measures were developed through the American Medical Association-convened Physician Consortium for Performance Improvement (PCPI) independent measure development process, which marked the first time a medical specialty society followed this process. Guidelines, measures, and consensus papers reviewed for the period 1998 to 2008 using the National Guidelines Clearinghouse, the National Quality Measures Clearinghouse, PubMed, MEDLINE, and the Cochrane Library were evaluated using a framework to determine the acceptability of each guideline or other evidence review document for measures development. Recommendation statements based on level of evidence, importance, validity, and gap in care were developed into candidate measures. A panel of experts from representative organizations vetted the measures. A period of public comment was followed by approval from the American Academy of Neurology and the PCPI. RESULTS: Literature search identified 160 relevant recommendation statements from 19 guidelines and 2 consensus papers. Systematic assessment resulted in 20 recommendation statements that were refined to 8 candidate measures by the expert panel. The measures are relevant to seizure type and frequency, etiology or epilepsy syndrome, EEG, neuroimaging, antiepileptic drug side effects, safety issues, referral for refractory epilepsy, and issues for women of childbearing potential. CONCLUSION: There is a reasonable evidence base, and consensus for, deriving performance measures for quality of epilepsy care. It is anticipated that implementation of these performance measures will improve care for patients with epilepsy if adopted by providers.

Quality improvement in neurology: AAN Parkinson disease quality measures: report of the Quality Measurement and Reporting Subcommittee of the American Academy of Neurology.

BACKGROUND: Measuring the quality of health care is a fundamental step toward improving health care and is increasingly used in pay-for-performance initiatives and maintenance of certification requirements. Measure development to date has focused on primary care and common conditions such as diabetes; thus, the number of measures that apply to neurologic care is limited. The American Academy of Neurology (AAN) identified the need for neurologists to develop measures of neurologic care and to establish a process to accomplish this. OBJECTIVE: To adapt and test the feasibility of a process for independent development by the AAN of measures for neurologic conditions for national measurement programs. METHODS: A process that has been used nationally for measure development was adapted for use by the AAN. Topics for measure development are chosen based upon national priorities, available evidence base from a systematic literature search, gaps in care, and the potential impact for quality improvement. A panel composed of subject matter and measure development methodology experts oversees the development of the measures. Recommendation statements and their corresponding level of evidence are reviewed and considered for development into draft candidate measures. The candidate measures are refined by the expert panel during a 30-day public comment period and by review by the American Medical Association for Current Procedural Terminology (CPT) II codes. All final AAN measures are approved by the AAN Board of Directors. RESULTS: Parkinson disease (PD) was chosen for measure development. A review of the medical literature identified 258 relevant recommendation statements. A 28-member panel approved 10 quality measures for PD that included full specifications and CPT II codes. CONCLUSION: The AAN has adapted a measure development process that is suitable for national measurement programs and has demonstrated its capability to independently develop quality measures.

Changing motor synergies in chronic stroke.

Synergies are thought to be the building blocks of vertebrate movements. The inability to execute synergies in properly timed and graded fashion precludes adequate functional motor performance. In humans with stroke, abnormal synergies are a sign of persistent neurological deficit and result in loss of independent joint control, which disrupts the kinematics of voluntary movements. This study aimed at characterizing training-related changes in synergies apparent from movement kinematics and, specifically, at assessing: 1) the extent to which they characterize recovery and 2) whether they follow a pattern of augmentation of existing abnormal synergies or, conversely, are characterized by a process of extinction of the abnormal synergies. We used a robotic therapy device to train and analyze paretic arm movements of 117 persons with chronic stroke. In a task for which they received no training, subjects were better able to draw circles by discharge. Comparison with performance at admission on kinematic robot-derived metrics showed that subjects were able to execute shoulder and elbow joint movements with significantly greater independence or, using the clinical description, with more isolated control. We argue that the changes we observed in the proposed metrics reflect changes in synergies. We show that they capture a significant portion of the recovery process, as measured by the clinical Fugl-Meyer scale. A process of "tuning" or augmentation of existing abnormal synergies, not extinction of the abnormal synergies, appears to underlie recovery.

Practice parameter: treatment of nervous system Lyme disease (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology.

OBJECTIVE: To provide evidence-based recommendations on the treatment of nervous system Lyme disease and post-Lyme syndrome. Three questions were addressed: 1) Which antimicrobial agents are effective? 2) Are different regimens preferred for different manifestations of nervous system Lyme disease? 3) What duration of therapy is needed? METHODS: The authors analyzed published studies (1983-2003) using a structured review process to classify the evidence related to the questions posed. RESULTS: The panel reviewed 353 abstracts which yielded 112 potentially relevant articles that were reviewed, from which 37 articles were identified that were included in the analysis. CONCLUSIONS: There are sufficient data to conclude that, in both adults and children, this nervous system infection responds well to penicillin, ceftriaxone, cefotaxime, and doxycycline (Level B recommendation). Although most studies have used parenteral regimens for neuroborreliosis, several European studies support use of oral doxycycline in adults with meningitis, cranial neuritis, and radiculitis (Level B), reserving parenteral regimens for patients with parenchymal CNS involvement, other severe neurologic symptomatology, or failure to respond to oral regimens. The number of children (> or =8 years of age) enrolled in rigorous studies of oral vs parenteral regimens has been smaller, making conclusions less statistically compelling. However, all available data indicate results are comparable to those observed in adults. In contrast, there is no compelling evidence that prolonged treatment with antibiotics has any beneficial effect in post-Lyme syndrome (Level A).

Interferon-beta-1a induces increases in vascular cell adhesion molecule: implications for its mode of action in multiple sclerosis.

We investigated soluble vascular cell adhesion molecule-1 (sVCAM) levels and MRI lesions over 24 weeks in 15 Relapsing Remitting MS (RRMS) patients randomized prospectively to receive once-weekly (qw) IFN-beta-1a 30 mug intramuscularly (IM) (Group I, 8 patients) or three-times-weekly (tiw) IFN-beta-1a 44 mug subcutaneously (SC) (Group II, 7 patients). Both groups demonstrated a significant increase in sVCAM during treatment when compared to pre-treatment levels. Patients on IFN-beta-1a 44 mug SC tiw had a significant (p<0.0001) mean increase in sVCAM of 321.9 ng/ml which was significantly greater (p<0.0001) than with IFN-beta-1a 30 mug IM qw (68.6 ng/ml). There was a negative correlation between combined unique (CU) MRI lesions and sVCAM levels within the IFN-beta-1a 44 mug SC tiw group (slope=-0.00106, p=0.009). We postulate that the mode of action of IFN-beta therapy in MS may involve the induction of an increase in sVCAM. sVCAM could bind VLA-4 on T-cells and intercept their adhesion to the blood brain barrier (BBB). This mechanism is consistent with the observed clinical effect of IFN-beta in reducing MRI contrast enhancing lesions.

Comparative tolerance of IFN beta-1a regimens in patients with relapsing multiple sclerosis. The EVIDENCE study.

The EVIDENCE study was a direct comparative study of two dose regimens of interferon (IFN) beta-1a used in the treatment of relapsing-remitting multiple sclerosis (RRMS): 30 mcg intramuscularly once weekly (qw; n=338) and 44 mcg subcutaneously three times weekly (tiw; n=339). The study continued for an average of 64 weeks. The safety population consisted of all patients receiving at least one dose of study drug. Clinical assessments occurred every 4 weeks for 24 weeks and then every 12 weeks. Blood tests for safety were taken at baseline and at weeks 4 and 12, and every 12 weeks thereafter. Overall adverse events were more common with the 44 mcg tiw regimen (p=0.007), and were due predominantly to differences in injection-site reactions. The majority of adverse events were rated mild by investigators. Hepatic and haematological adverse events and asymptomatic laboratory abnormalities were more common with 44 mcg tiw (p<0.001),with no difference seen for severe events. Flu-like symptoms were more common with 30 mcg qw (p=0.031), were more severe and persisted for longer. Serious adverse events were comparable for both groups, as were drug discontinuations. In conclusion, although adverse events were more common with high-dose, high-frequency IFN therapy, differences were primarily for mild events and did not affect treatment adherence. Based on superior clinical and magnetic resonance imaging outcomes over an average of 64 weeks, coupled with modest safety differences, the risk-benefit ratio for IFN therapy in RRMS favours the 44 mcg tiw regimen over this period of time.

Quantitative functional measures in MS: what is a reliable change?

As a first step toward understanding which changes should be considered as meaningful, the authors assessed the reliability of quantitative functional tests on 5 consecutive days in 63 patients with MS, determining the range of measurement variability present when patients are clinically stable. Time to walk 25 feet (T25FW) and the 9-hole peg test (9HPT) varied by <20% of individual mean scores on repeated testing. Therefore, a 20% change on these tests can be considered to be the threshold that reliably indicates a true change in function for an individual.

Th1 cytokines stimulate RANTES chemokine secretion by human astroglial cells depending on de novo transcription.

Beta-chemokines induce the directional migration of monocytes and T lymphocytes that are implicated in the pathogenesis of multiple sclerosis (MS) lesions. RANTES is a member of the beta-chemokine family that has been detected in the lesions of MS patients. However, the cellular sources of RANTES message and the molecular basis for the regulation of its production in MS lesions are not well understood. Glial cells may be a major source of RANTES in vivo and have been shown to produce RANTES in vitro. Thus, the objective of this study was to establish a model system for studying the regulation of RANTES expression by cytokines in cultured human glial cells, and to determine the mechanism involved in the process. We show that the Th1 cytokines TNF-alpha and IL-1beta independently induce RANTES mRNA and chemokine levels in human U-251 MG astroglial cells, and that these effects are time- and concentration-dependent. In addition, we demonstrate that both cytokines increased the rate of transcription of the RANTES gene, as estimated by in vitro nuclear transcript elongation assays. The transcriptional activity in TNF-alpha-treated U-251 MG cells started to increase at 2 h and peaked at 8 h, with levels more than 14 times greater than controls. We further show that NF-kappaB may play a critical role in the up-regulation of human RANTES gene expression in this system. Gel shift assays revealed an induction of in vitro nuclear extract binding activity to the NF-kappaB element of RANTES in cells incubated with the Th1 cytokines. These observations suggest that human astroglia, within diseased brain, may be stimulated to produce RANTES chemokine in response to TNF-alpha and IL-1beta, and that this effect of the Th1 cytokines is attributed to increase of transcription.

Glatiramer acetate inhibition of tumor necrosis factor-alpha-induced RANTES expression and release from U-251 MG human astrocytic cells.

Glatiramer acetate is an approved drug for the treatment of multiple sclerosis (MS). RANTES is a beta-family chemokine that manifests chemoattractant activity for T lymphocytes and monocytes/macrophages implicated in the pathogenesis of MS lesions. However, the effect of glatiramer acetate on the regulation of RANTES secretion in glial cells is unknown. In the present study, we demonstrate for the first time that treatment of human U-251 MG astrocytic cells with glatiramer acetate blocks tumor necrosis factor-alpha (TNF-alpha)-induced RANTES mRNA and protein in a dose- and time-dependent manner. This effect is attributed to inhibition of transcription and a 40% decrease in transcript stability. Furthermore, our electrophoretic mobility shift assays of nuclear extracts from TNF-alpha-treated cells reveal an increase in DNA-binding activity specific for the nuclear factor-kappa B (NF-kappaB) binding site, in the 5'-flanking promoter region of the human RANTES gene, and that this increase in NF-kappaB binding activity is prevented by pretreatment with glatiramer acetate or the NF-kappaB inhibitors. These findings suggest that glatiramer acetate may exert its therapeutic effect in MS partially through inhibiting NF-kappaB activation and chemokine production.

Comparison of RANTES chemokine induction by Th1 cytokines in human astroglial cell lines.

Multiple sclerosis (MS) is a primary inflammatory demyelinating disease of the human central nervous system, characterized by accumulation of mononuclear cells of hematogenous origin. RANTES is a C-C (beta)-chemokine family member with strong chemoattractant activity for lymphocytes and monocytes that are implicated in the pathogenesis of MS lesions. However, the cellular sources of RANTES message and the regulation of its secretion within diseased brain are poorly understood. Therefore, we carried out this study to compare the effect of Th1 cytokines on the induction of RANTES in different human astrocytic cell lines. IFN-gamma alone had little effect on RANTES production in both U-373MG and U-105MG cells, while TNF-alpha or IL-1beta alone had differential effects in the two cell lines. Low levels of RANTES chemokine were detected in culture supernatants from U-373MG cells. By contrast, TNF-alpha or IL-1beta dramatically increased RANTES secretion in U-105MG cells. Interestingly, different combination treatments of cells with the three cytokines synergistically induced RANTES release from both U-373MG and U-105MG cells. Consistent with these results, we found similar expression patterns for RANTES at the comparable steady-state mRNA levels in both cell lines. Furthermore, we showed that U-105MG cells treated with TNF-alpha and IL-1beta alone or in combination markedly induced increases in the rate of transcription of the RANTES chemokine gene. Our results indicate that these cell lines may be good model systems for studying the regulation of RANTES expression by cytokines in human glial cells.

Induction of RANTES chemokine expression in human astrocytic cells is dependent upon activation of NF-kappaB transcription factor.

RANTES is a C-C (beta)-family chemokine that is implicated in the migration of peripheral blood leukocytes to brain lesions in multiple sclerosis (MS), an inflammatory demyelinating disease of the central nervous system (CNS). Glial cells are active participants in the inflammatory response in the CNS, and they have been shown to respond to and produce a number of cytokines and chemokines in vivo and in vitro. Recently, we have shown inducibility of RANTES gene expression by TNF-alpha in human astrocytic cells. Therefore, the goal of the current study was to investigate the transcription activating factor involved in the process. We found that the induction of RANTES mRNA and protein by TNF-alpha in human astrocytic cells is associated with increased NF-kappaB DNA-binding activity. p65 and p50 were determined to be the components of the activated NF-kappaB transcription factor complex by supershift assay. In addition, the blockade of NF-kappaB activation by three known NF-kappaB inhibitors markedly reduced the TNF-alpha-induced RANTES expression at the mRNA and protein levels. Furthermore, the reduction in NF-kappaB binding activity to the promoter of the human RANTES gene caused by the NF-kappaB inhibitors parallels a decrease in RANTES expression in these cells. Our data suggest that NF-kappaB may mediate the induction of RANTES gene expression, in human glial cells, through its cognate cis-acting element.

Glatiramer acetate blocks interleukin-1-dependent nuclear factor-kappaB activation and RANTES expression in human U-251 MG astroglial cells.

RANTES is a basic 8-kDa polypeptide of the C-C chemokine subfamily with strong chemoattractant activity for T lymphocytes and monocytes/macrophages that are implicated in the pathogenesis of multiple sclerosis (MS) lesions. Glatiramer acetate is a drug recently approved for the treatment of MS. We therefore investigated the effect of glatiramer acetate on RANTES expression in glial cells in vitro. Treatment of human U-251 MG astroglial cells with glatiramer acetate blocks IL-1beta-induced RANTES chemokine production in a dose- and time-dependent manner. Glatiramer acetate also decreased steady-state levels of RANTES mRNA in these cells, which was attributable to reduced transcription, as assessed by nuclear run-on assays. In addition, we showed that NF-kappaB may be the transcriptional activator responsible for the IL-1beta-mediated RANTES gene expression in this system. Our data indicated that the IL-1beta-induced increase in RANTES was associated with an increase in in vitro nuclear extract binding activity specific for the NF-kappaB site in the promoter region of the RANTES gene. The increases in RANTES mRNA and protein expression were suppressed by the NF-kappaB inhibitors gliotoxin, isohelenin, and pyrrolidine dithiocarbamate (PDTC). Furthermore, we demonstrated that the increase in NF-kappaB DNA-binding activity was prevented by pretreatment with glatiramer acetate or the NF-kappaB inhibitors. Our results suggest that glatiramer acetate may inhibit IL-1beta-stimulated RANTES expression in human glial cells by blocking NF-kappaB activation, thus identifying part of the molecular basis for its anti-inflammatory and immunosuppressive effects in demyelinating diseases.

Mechanisms underlying the synergistic effect of Th1 cytokines on RANTES chemokine production by human glial cells.

RANTES is a beta-family chemokine with potent chemoattractant activity for lymphocytes and monocytes that are implicated in the pathogenesis of multiple sclerosis (MS) lesions. Glial cells have been shown to produce RANTES in response to stimulation with Th1 cytokines (IFN-gamma, TNF-alpha, and IL-1beta) in vitro, and they may be a major source of RANTES production within diseased brain. This study was undertaken to investigate the mechanism underlying the effect of the Th1 cytokines on the induction of RANTES in a model system for human astroglia. We show that IFN-gamma has a synergistic effect with TNF-alpha or IL-1beta on RANTES mRNA and chemokine production in this system. We further show that the combination treatment of IFN-gamma and TNF-alpha, or IFN-gamma and IL-1beta induced 3-fold higher levels of RANTES gene transcription than seen with either TNF-alpha or IL-1beta alone, as measured by in vitro nuclear transcript elongation assays. In addition, we found that IFN-gamma decreased the rate of degradation of RANTES mRNA caused by TNF-alpha or IL-1beta. The t(1/2) of RANTES mRNA was 25+/-1 h in the presence of both IFN-gamma and TNF-alpha, as compared to a t(1/2) of 15+/-1 h in the presence of TNF-alpha alone. This 10 h difference represents an approximate 70% increment in RANTES mRNA half-life. Thus, these results suggest that both increased RANTES gene transcription and increased RANTES mRNA stability may account for the synergistic effect of Th1 cytokines on the up-regulation of RANTES expression in human astroglial cells.

Performance of the dynamic single photon emission computed tomography (dSPECT) method for decreasing or increasing activity changes.

Radionuclide imaging is now widely used whenever functional information is required. We present a new approach to dynamic SPECT imaging (dSPECT method) that uses a single slow rotation of a conventional camera and allows us to reconstruct a series of 3D images corresponding to the radiotracer distribution in the body at various times. Using simulations of various camera configurations and acquisition protocols, we have shown that this method is able to reconstruct washout half-lives with an accuracy greater than 90% when used with triple-head SPECT cameras. Accuracy decreases when using fewer camera heads, but dual-head geometries still give an accuracy greater than 80% for short and 90% for long half-lives and about 50-75% for single-head systems. Dynamic phantom experiments have yielded similar results. Presence of attenuation and background activity does not affect the accuracy of the dSPECT reconstructions. In all situations investigated satisfactory dynamic images were produced. A preliminary normal volunteer study measuring renal function was performed. The reconstructed dynamic images may be presented as a three-dimensional movie showing movement of the tracer through the kidneys and the measurement of the regional renal function can be performed. The time-activity curves determined from this dSPECT data are very similar to those obtained from dynamic planar scans.

Inactivation gating and 4-AP sensitivity in human brain Kv1.4 potassium channel.

Voltage-gated K(+) channels vary in sensitivity to block by 4-aminopyridine (4-AP) over a 1000-fold range. Most K(+) channel phenotypes with leucine at the fourth position (L4) in the leucine heptad repeat region, spanning the S4-S5 linker, exhibit low 4-AP sensitivity, while channels with phenylalanine exhibit high sensitivity. Mutational analysis on delayed rectifier type K(+) channels demonstrate increased 4-AP sensitivity upon mutation of the L4 heptad leucine to phenylalanine. This mutation can also influence inactivation gating, which is known to compete with 4-AP in rapidly inactivating A-type K(+) channels. Here, in a rapidly inactivating human brain Kv1.4 channel, we demonstrate a 400-fold increase in 4-AP sensitivity following substitution of L4 with phenylalanine. Accompanying this mutation is a slowing of inactivation, an acceleration of deactivation, and depolarizing shifts in the voltage dependence of activation and steady-state inactivation. To test the relative role of fast inactivation in modulating 4-AP block, N-terminal deletions of the fast inactivation gate were carried out in both channels. These deletions produced no change in 4-AP sensitivity in the mutant channel and approximately a six-fold increase in the wild type channel. These results support the view that changes at L4 which increase 4-AP sensitivity are largely due to 4-AP binding and may, in part, arise from alterations in channel conformation. Primarily, this study demonstrates that the fast inactivation gate is not a critical determinant of 4-AP sensitivity in Kv1.4 channels.

Multiple Sclerosis: Symptomatic Treatment.

Therapy for multiple sclerosis (MS) that prevents exacerbation of the disease and slows the progression of disability has not diminished the importance of treating symptoms. Because the new agents are not curative and rarely reverse existing deficits, many patients under treatment have or will have persistent symptoms. Many neurologic symptoms are seen in patients with MS, but it is important to recognize that some nonneurologic symptoms, such as pain, fatigue, and mood disturbance, are common and may cause significant disability. The first and most important step in the management of symptoms is to discuss the symptoms with the patient on an ongoing basis. The second step is to recognize treatable symptoms and to apply the appropriate strategies for management. There have been promising results with experimental agents, primarily potassium channel blockers, that may improve function in demyelin-ated fiber pathways and that offer the possibility of treatment for a range of symptoms. At present, the management of symptoms varies, depending on the symptom, and it involves the coordinated application of a range of treatment approaches including medication, lifestyle changes, rehabilitation, and, in some cases, surgery.