Exploring organizational support for the provision of structured self-management education for people with Type 2 diabetes: findings from a qualitative study.

AIM: To explore the organizational context in which Type 2 diabetes structured group education is provided. METHODS: Four Clinical Commissioning Groups in England providing Type 2 diabetes structured self-management education participated in a qualitative study exploring the context for provision of that education. Using UK National Diabetes Audit returns, two Clinical Commissioning Groups were selected that had non-attendance rates of ≤25%, and two that had non-attendance rates of ≥50%. Between May 2016 and August 2017, 20 interviews were conducted with Clinical Commissioning Group staff including: commissioners, healthcare professionals, managers, general practitioners and diabetes educators. Data gathering was prolonged as it proved challenging to engage with healthcare staff as a result of frequent local restructuring and service disruption. RESULTS: Local audits revealed discrepancies in basic data such as referral and attendance numbers compared with national audit data. There was a commonality in the themes identified from interviews: diabetes education was rarely embedded in service structure; where education uptake was poor, a lack of central support to delivery teams was noticeable; and where education uptake was positive, delivery teams were actively engaged, sometimes relying on enthusiastic individuals. Both situations put the local sustainability of diabetes education at risk. CONCLUSIONS: There appears to be a link between attendance rates and organizational issues, therefore, when considering how to increase attendance rates, the state of the diabetes education infrastructure should be reviewed. Good uptake of diabetes education can be too reliant on the enthusiastic commitment of small teams or individuals delivering the education.

Pilot feasibility study examining a structured self-management diabetes education programme, DESMOND-ID, targeting HbA1c in adults with intellectual disabilities.

AIM: To report on the outcomes of a pilot feasibility study of a structured self-management diabetes education programme targeting HbA1c . METHODS: We conducted a two-arm, individually randomized, pilot superiority trial for adults with intellectual disability and Type 2 diabetes mellitus. A total of 66 adults with disabilities across the UK met the eligibility criteria. Of these, 39 agreed to participate and were randomly assigned to either the DESMOND-ID programme (n = 19) or a control group (n = 20). The programme consisted of seven weekly educational sessions. The primary outcome was HbA1c level, and secondary outcomes included BMI, diabetes illness perceptions, severity of diabetes, quality of life, and attendance rates. RESULTS: This study found that the DESMOND-ID programme was feasible to deliver. With reasonable adjustments, the participants could be recruited successfully, and could provide consent, complete the outcome measures, be randomized to the groups and attend most of the sessions, with minimal loss to follow-up. The fixed-effects model, the interaction between occasion (time) and condition, showed statistically significant results (0.05 level) for HbA1c ; however, the CI was large. CONCLUSION: This is the first published study to adapt and pilot a national structured self-management diabetes education programme for adults with intellectual disability. This study shows it is possible to identify, recruit, consent and randomize adults with intellectual disabilities to an intervention or control group. Internationally, the results of this pilot are promising, demonstrating that a multi-session education programme is acceptable and feasible to deliver. Its effectiveness should be further tested in an adequately powered trial.

Projecting the Supply and Demand for Certified Genetic Counselors: a Workforce Study.

As of May 2017, there were 4242 Certified Genetic Counselors (CGC) (American Board of Genetic Counseling, Inc. 2017) and 41 graduate-level genetic counseling training programs (Accreditation Council for Genetic Counseling 2017) in North America, and the demand for CGCs continues to increase. In the Fall of 2015 the Genetic Counselor Workforce Working Group, comprised of representatives from the American Board of Genetic Counseling (ABGC), the Accreditation Council for Genetic Counseling (ACGC), the Association of Genetic Counseling Program Directors (AGCPD), the American Society of Human Genetics (ASHG), and the National Society of Genetic Counselors (NSGC) commissioned a formal workforce study to project supply of and demand for CGCs through 2026. The data indicate a shortage of genetic counselors engaged in direct patient care. Assuming two scenarios for demand, supply is expected to reach equilibrium between 2024 and 2030. However, given the rate of growth in genetic counseling training programs in the six months since the study was completed, it is reasonable to expect that the number of new programs may be higher than anticipated by 2026. If true, and assuming that growth in programs is matched by equivalent growth in clinical training slots, the supply of CGCs in direct patient care would meet demand earlier than these models predict.

Deficiencies in postgraduate training for healthcare professionals who provide diabetes education and support: results from the Diabetes Attitudes, Wishes and Needs (DAWN2) study.

AIMS: To consider the global provision of self-management diabetes education and training for healthcare professionals using data from the second Diabetes Attitudes, Wishes and Needs (DAWN2) study. METHODS: A total of 4785 healthcare professionals caring for people with diabetes were surveyed in 17 countries to assess diabetes healthcare provision, self-management support and training. RESULTS: Of the healthcare professionals surveyed, 33.5% received formal postgraduate training in self-management (19.3-51.4% across countries) and 62.9% received training for medical management of diabetes (47.6-70.6% variation). Training in psychological management was low (19.1%), ranging from 3.6 to 36.5%, while 20.4% (a range of 3.6-36.4% across countries) had received no postgraduate training. Overall, the greatest training need was in the management of psychological aspects of diabetes (59.5%). For some, training in a domain was positively associated with a perceived need for further training. Communication skills, for example, listening (76.9%) and encouraging questions (76.1%), were the skills most widely used. Discussion of emotional issues was limited; 31-60% of healthcare professionals across the different countries reported that this only occurred if initiated by patients. Approximately two-thirds of participants reported a need for major improvements in emotional/psychological support, but few had received training in this area, with consistent findings across professional affiliations. CONCLUSIONS: The present study shows that healthcare professionals report being insufficiently equipped to provide diabetes self-management education, including emotional and psychological aspects of diabetes, and many are not receiving postgraduate training in any part (including medical care) of the management of diabetes. It is paramount that those responsible for the continuing professional development of healthcare professionals address this skills gap.

Self-monitoring of blood glucose versus self-monitoring of urine glucose in adults with newly diagnosed Type 2 diabetes receiving structured education: a cluster randomized controlled trial.

AIMS: To compare the effectiveness and acceptability of self-monitoring of blood glucose with self-monitoring of urine glucose in adults with newly diagnosed Type 2 diabetes. METHODS: We conducted a multi-site cluster randomized controlled trial with practice-level randomization. Participants attended a structured group education programme, which included a module on self-monitoring using blood glucose or urine glucose monitoring. HbA1c and other biomedical measures as well as psychosocial data were collected at 6, 12 and 18 months. A total of 292 participants with Type 2 diabetes were recruited from 75 practices. RESULTS: HbA1c levels were significantly lower at 18 months than at baseline in both the blood monitoring group [mean (se) -12 (2) mmol/mol; -1.1 (0.2) %] and the urine monitoring group [mean (se) -13 (2) mmol/mol; -1.2 (0.2)%], with no difference between groups [mean difference adjusted for cluster effect and baseline value = -1 mmol/mol (95% CI -3, 2); -0.1% (95% CI -0.3, 0.2)]. Similar improvements were observed for the other biomedical outcomes, with no differences between groups. Both groups showed improvements in total treatment satisfaction, generic well-being, and diabetes-specific well-being, and had a less threatening view of diabetes, with no differences between groups at 18 months. Approximately one in five participants in the urine monitoring arm switched to blood monitoring, while those in the blood monitoring arm rarely switched (18 vs 1% at 18 months; P < 0.001). CONCLUSIONS: Participants with newly diagnosed Type 2 diabetes who attended structured education showed similar improvements in HbA1c levels at 18 months, regardless of whether they were assigned to blood or urine self-monitoring.

Stability and predictive utility, over 3 years, of the illness beliefs of individuals recently diagnosed with Type 2 diabetes mellitus.

AIM: To determine the stability of beliefs of patients with Type 2 diabetes about their diabetes over 3 years, following diagnosis. METHODS: Data were collected as part of a multicentre cluster randomized controlled trial of a 6-h self-management programme, across 207 general practices in the UK. Participants in the original trial were eligible for follow-up with biomedical data (HbA1c levels, blood pressure, weight, blood lipid levels) collected at the practice, and questionnaire data collected by postal distribution and return. Psychological outcome measures were depression (Hospital Anxiety and Depression Scale) and diabetes distress (Problem Areas in Diabetes scale). Illness beliefs were assessed using the Illness Perceptions Questionnaire-Revised and the Diabetes Illness Representations Questionnaire scales. RESULTS: At 3-year follow-up, all post-intervention differences in illness beliefs between the intervention and the control group remained significant, with perceptions of the duration of diabetes, seriousness of diabetes and perceived impact of diabetes unchanged over the course of the 3-year follow-up. The control group reported a greater understanding of diabetes during the follow-up, and the intervention group reported decreased responsibility for diabetes outcomes during the follow-up. After controlling for 4-month levels of distress and depression, the perceived impact of diabetes at 4 months remained a significant predictor of distress and depression at 3-year follow-up. CONCLUSIONS: Peoples' beliefs about diabetes are formed quickly after diagnosis, and thereafter seem to be relatively stable over extended follow-up. These early illness beliefs are predictive of later psychological distress, and emphasize the importance of initial context and provision of diabetes care in shaping participants' future well-being.

Increasing capacity to deliver diabetes self-management education: results of the DESMOND lay educator non-randomized controlled equivalence trial.

AIM: To develop and test a format of delivery of diabetes self-management education by paired professional and lay educators. METHODS: We conducted an equivalence trial with non-randomized participant allocation to a Diabetes Education and Self Management for Ongoing and Newly Diagnosed Type 2 diabetes (DESMOND) course, delivered in the standard format by two trained healthcare professional educators (to the control group) or by one trained lay educator and one professional educator (to the intervention group). A total of 260 people with Type 2 diabetes diagnosed within the previous 12 months were referred for self-management education as part of routine care and attended either a control or intervention format DESMOND course. The primary outcome measure was change in illness coherence score (derived from the Diabetes Illness Perception Questionnaire-Revised) between baseline and 4 months after attending education sessions. Secondary outcome measures included change in HbA1c level. The trial was conducted in four primary care organizations across England and Scotland. RESULTS: The 95% CI for the between-group difference in positive change in coherence scores was within the pre-set limits of equivalence (difference = 0.22, 95% CI 1.07 to 1.52). Equivalent changes related to secondary outcome measures were also observed, including equivalent reductions in HbA1c levels. CONCLUSION: Diabetes education delivered jointly by a trained lay person and a healthcare professional educator with the same educator role can provide equivalent patient benefits. This could provide a method that increases capacity, maintains quality and is cost-effective, while increasing access to self-management education.

Diabetes self-management education: acceptability of using trained lay educators.

BACKGROUND: The use of lay people to deliver education programmes for people with chronic conditions is a potential method of addressing healthcare staff capacity and increasing the cost efficiency of delivering education. This qualitative substudy is embedded within an equivalence trial (2008-2011 including development stage). OBJECTIVES: In the qualitative substudy, we aimed to elicit the views of key stakeholders (patients, educators) about using lay people to deliver education to people recently diagnosed with type 2 diabetes, alongside a healthcare professional educator with an equal role. In this way, we sought to explore perceptions about acceptability and also contribute to understanding the reasons underlying positive or negative quantitative findings from main trial. METHODS: We conducted 27 telephone interviews with a purposive sample of patients, lay educators and healthcare professional educators involved in the main trial. Thematic analysis of transcribed data was underpinned by the constant comparative approach and structured using Framework methodology. RESULTS: Overall, the data suggested that the use of lay educators was acceptable to educators and patients. Perceived difference in knowledge levels between lay and healthcare professional educators did not appear to have an impact on perceived acceptability or the effectiveness of the education received. Additional themes explored were related to peer status of educators and feasibility. Some concerns were raised about lay educators with diabetes, transferring personal issues and about the impact of healthcare professional time taken up by mentoring and supporting lay educators. CONCLUSIONS: Positive perceptions about the use of lay educators support the positive quantitative findings from the main trial. Acceptability is an important consideration in relation to implementation of the model of delivery studied. Concerns raised within the interviews should be considered in the design of training for lay educators. TRIAL REGISTRATION NUMBER: ISRCTN 99350009.

Depressive symptoms in the first year from diagnosis of Type 2 diabetes: results from the DESMOND trial.

AIMS: To describe the course of depressive symptoms during the first year after diagnosis of Type 2 diabetes. METHODS: Post hoc analysis of data from a randomized controlled trial of self-management education for 824 individuals newly diagnosed with Type 2 diabetes. Participants completed the Depression scale of the Hospital Anxiety and Depression Scale after diagnosis and at 4, 8 and 12 months follow-up. Participants also completed the Problem Areas in Diabetes scale at 8 and 12 months follow-up. We present descriptive statistics on prevalence and persistence of depressive symptoms. Logistic regression is used to predict possible depression cases, and multiple regression to predict depressive symptomatology. RESULTS: The prevalence of depressive symptoms in individuals recently diagnosed with diabetes (18-22% over the year) was not significantly different from normative data for the general population (12%) in the UK. Over 20% of participants indicated some degrees of depressive symptoms over the first year of living with Type 2 diabetes; these were mostly transient episodes, with 5% (1% severe) reporting having depressive symptoms throughout the year. At 12 months post diagnosis, after controlling for baseline depressive symptoms, diabetes-specific emotional distress was predictive of depressive symptomatology. CONCLUSIONS: The increased prevalence of depressive symptoms in diabetes is not manifest until at least 1 year post diagnosis in this cohort. However, there are a significant number of people with persistent depressive symptoms in the early stages of diabetes, and diabetes-specific distress may be contributing to subsequent development of depressive symptoms in people with Type 2 diabetes.

How can structured self-management patient education improve outcomes in people with type 2 diabetes?

Type 2 diabetes (T2DM) is a long-term chronic condition that is complex to manage, with the majority of management being done by the person with diabetes outside of the clinical setting. Because of its complexities, effective self-management requires skills, confidence and the ability to make decisions and choices about treatments and lifestyle on a day-to-day basis. Equipping a person with these self-management skills is in itself challenging and it is now widely accepted that structured education is an integral part of the management of T2DM. This paper explores whether structured self-management education can improve outcomes in people with diabetes. The authors explore what self-management education is, why it is needed and then go on to examine the recent evidence from clinical trials from 2006 onwards.

Experiences with rotavirus vaccines: can we improve rotavirus vaccine impact in developing countries?

Rotavirus vaccines have been introduced into over 95 countries globally and demonstrate substantial impact in reducing diarrheal mortality and diarrheal hospitalizations in young children. The vaccines are also considered by WHO as "very cost effective" interventions for young children, particularly in countries with high diarrheal disease burden. Yet the full potential impact of rotavirus immunization is yet to be realized. Large countries with big birth cohorts and where disease burden is high in Africa and Asia have not yet implemented rotavirus vaccines at all or at scale. Significant advances have been made demonstrating the impact of the vaccines in low- and lower-middle income countries, yet the modest effectiveness of the vaccines in these settings is challenging. Current research highlights these challenges and considers alternative strategies to overcome them, including alternative immunization schedules and host factors that may inform us of new opportunities.

Biomedical, lifestyle and psychosocial characteristics of people newly diagnosed with Type 2 diabetes: baseline data from the DESMOND randomized controlled trial.

AIMS: To describe the characteristics of newly diagnosed people with Type 2 diabetes (T2DM) and compare these with published studies. METHODS: Baseline data of participants recruited to the DESMOND randomized controlled trial conducted in 13 sites across England and Scotland were used. Biomedical measures and questionnaires on psychological characteristics were collected within 4 weeks of diagnosis. RESULTS: Of 1109 participants referred, 824 consented to participate (74.3%). Mean (+/- sd) age was 59.5 +/- 12 years and 54.9% were male. Mean HbA(1c) was 8.1 +/- 2.1% and did not differ by gender. Mean body mass index (BMI) was significantly higher in women (33.7 vs. 31.3 kg/m2; P < 0.001); 69% of women and 54% of men were obese (BMI > 30 kg/m2). Total cholesterol was significantly higher in women (5.6 vs. 5.2 mmol/l; P < 0.001). Overall, 14.7% reported smoking. Percentages reporting recommended levels of vigorous activity (> or = 3 times/week) and moderate activity (> or = 5 times/week) were 10.6 and 16.0%, respectively, and were lower in women. Specific illness beliefs included 73% being unclear about symptoms and only 54% believing diabetes is a serious condition. Symptoms indicative of depression were reported by significantly more women than men (16.1% vs. 8.2%; P = 0.001). CONCLUSION: Data from this large and representative cohort of newly diagnosed people with T2DM show that many have modifiable cardiovascular risk factors. Comparison with the literature suggests that the profile of the newly diagnosed may be changing, with lower HbA1c and higher prevalence of obesity. Many expressed beliefs about and poor understanding of their diabetes that need to be addressed in order for them to engage in effective self-management.

'Educator talk' and patient change: some insights from the DESMOND (Diabetes Education and Self Management for Ongoing and Newly Diagnosed) randomized controlled trial.

AIMS: To determine whether differences in the amount of time educators talk during a self-management education programme relate to the degree of change in participants' reported beliefs about diabetes. METHOD: Educators trained to be facilitative and non-didactic in their approach were observed delivering the DESMOND self-management programme for individuals newly diagnosed with Type 2 diabetes. Observers used 10-s event coding to estimate the amount of time educators spoke during different sessions in the programme. Facilitative as opposed to didactic delivery was indicated by targets for levels of educator talk set for each session. Targets were based on earlier pilot work. Using the revised Illness Perceptions Questionnaire (IPQ-R) and the Diabetes Illness Representations Questionnaire (DIRQ), participants completed measures of: perceived duration of diabetes (timeline IPQ-R), understanding of diabetes (coherence IPQ-R), personal responsibility for influencing diabetes (personal responsibility IPQ-R), seriousness of diabetes (seriousness DIRQ) and impact on daily life (impact DIRQ), before and after the education programme. RESULTS: Where data from the event coding indicated educators were talking less and meeting targets for being less didactic, a greater change in reported illness beliefs of participants was seen. However, educators struggled to meet targets for most sessions of the programme. CONCLUSION: The amount of time educators talk in a self-management programme may provide a practical marker for the effectiveness of the education process, with less educator talk denoting a more facilitative/less didactic approach. This finding has informed subsequent improvements to a comprehensive quality development framework, acknowledging that educators need ongoing support to facilitate change to their normal educational style.

Ictal onset slow potential shifts recorded with hippocampal depth electrodes.

PURPOSE: Reports of direct current shifts at the onset of scalp-recorded seizures prompted us to inspect depth-recorded seizures for the presence of similar slow potential shifts at the onset of the seizure to determine whether slow potential (SP) shifts actually occur at the onset of depth-recorded seizures and if these shifts can facilitate localization of the seizure focus. METHODS: With the low frequency filter "opened" (LLF=0.1 Hz, HLF=70 Hz, 3 dB/octave), 32 seizures recorded with hippocampal depth and subdural electrodes were visually inspected to identify an SP shift at the onset of the seizure. A seizure was considered as having an SP shift when the slow potential waveform was > 1.5 sec in duration and > 100 microV in amplitude. Seizures were obtained from 5 subjects; 4 underwent epilepsy surgery (3=Engel I, 1=Engel II) and one received VNS. SP shift duration, peak voltage and polarity were measured for each seizure. The ability to identify seizures based on SP shift configuration was also evaluated. RESULTS: In 84% of the seizures, ictal onset was associated with a localized SP shift. Shift duration ranged from 1.5 sec to 11.5 sec (96% > 2 sec, 62% > 5 sec). The maximum shift ranged from 139 microV to 2305 microV (mean = 1123 microV, SD = 660 microV). In all the seizures, polarity was positive at the point of maximum shift. By visually examining the SP shift, seizures could be identified as originating from the same focus or from different foci. CONCLUSIONS: The onset of depth-recorded seizures appears to be commonly associated with a localized positive SP shift. An SP shift at the onset of depth-recorded seizures is likely to be a useful visual aid for localizing electrographic seizure onset.

Pyogenic cervical osteomyelitis presenting as a massive prevertebral abscess in a patient with rheumatoid arthritis.

Pre-existing rheumatoid arthritis appeared to have masked the diagnosis and contributed to a succession of hazardous events in a 58-year-old man with pyogenic cervical osteomyelitis. A massive prevertebral abscess and near asphyxiation finally led to the diagnosis of an indolent Staphylococcus aureus infection in a course marked by antecedent staphylococcal sepsis, a series of dangerous cervical spine chiropractic manipulations in the presence of advanced bony destruction, and, ultimately, cervical spine bony collapse and gibbus formation. The absence of myelopathy despite long-standing progressive advanced destruction is noteworthy. The roentgenologic documentation of this progression was unique. This appears to be the first fully documented case of cervical spine osteomyelitis presenting as a prevertebral abscess in a patient with rheumatoid arthritis.

Brain edema following an experimental missile wound to the brain.

Brain edema occurs after brain injury and may be life threatening. The occurrence and type of brain edema, its magnitude, and time course have never been ascertained following a missile wound to the brain. We therefore measured the development of brain edema in a series of cats in which a right cerebral hemisphere wound was made with a 2.0 mm, 31.7 mg steel sphere with a velocity of 240-300 m/s (0.9-1.4 J). The entire brain was surveyed for postwounding brain edema by determining the wet weight minus dry weight. Brain edema was seen to develop only in the white matter about the missile wound track in the injured cerebral hemisphere. There, brain water rose from 66 to 73%; white matter sodium also increased significantly from approximately 150 mEq/kg dry weight to 254 mEq/kg dry weight. Potassium levels remained essentially unchanged. This vasogenic edema was relatively mild, peaked at 24-48 h after wounding, and resolved spontaneously within a week without specific treatment. We infer that brain edema following an uncomplicated cerebral missile wound in the human brain is also mild, self-limited, and may resolve spontaneously without special treatment.

Cerebral cardiovascular and respiratory variables after an experimental brain missile wound.

Brain missile wounding (BMW) affects brainstem and medullary cadiorespiratory functions leading to immediate systemic hypertension, bradycardia, and apnea. Secondary complications may also occur because of subsequent changes in systemic and intracranial physiological variables. To delineate the immediate and secondary effects of BMW, we monitored changes in several cerebral and cardiorespiratory parameters in pentobarbital-anesthetized spontaneously breathing cats before wounding and up to 90 min afterward. Total and regional cerebral blood flow (rCBF) and cardiac output (CO) were measured (microsphere technique) and arterial blood was sampled for pH, PO2 and PCO2 once before BMW and one to four times afterward. Mean arterial blood pressure (MABP), intracranial pressure (ICP), cerebral perfusion pressure (CPP = MABP - ICP), electrocardiogram (ECG), heart rate (HR), and electroencephalogram (EEG) were continuously recorded. Respiratory frequency (f), tidal volume (Vt), and ventilation (V) were recorded during each flow measurement and periodically throughout the experiment. Four unwounded cats served as controls and 15 cats were wounded at 1.4 J fronto-occipitally through an intact cranium. Unwounded cats showed no significant changes in any physiological variable measured during a 100 min experimentation period. Four wounded cats survived a 90 min post-BMW period and had only a transient brainstem effect including a 50% increase in MABP concurrently with 50% reductions in the f and HR. Nonsurvivors (11 of 15) lived from 1 to 41 min after wounding. These cats initially demonstrated similar changes in MABP, f, and HR to survivors, but these variables remained unstable, possibly indicating a persisting brainstem damage. Apnea accounted for death in 10 of 11 nonsurvivors. Although the primary brainstem effect might have existed in all nonsurvivors, it appears that only one cat died from reduced respiration alone. Others had one or several postwounding secondary complications: abruptly increased ICP producing a negative CPP, extreme reductions in CO or CBF and ventilation. Cardiac arrest occurred once. Thus, post-BMW mortality cannot be consistently ascribed to the impairment of a single physiological variable.

Ladder beam and camera video recording system for evaluating forelimb and hindlimb deficits after sensorimotor cortex injury in rats.

Hindlimb and forelimb deficits in rats caused by sensorimotor cortex lesions are frequently tested by using the narrow flat beam (hindlimb), the narrow pegged beam (hindlimb and forelimb) or the grid-walking (forelimb) tests. Although these are excellent tests, the narrow flat beam generates non-parametric data so that using more powerful parametric statistical analyses are prohibited. All these tests can be difficult to score if the rat is moving rapidly. Foot misplacements, especially on the grid-walking test, are indicative of an ongoing deficit, but have not been reliably and accurately described and quantified previously. In this paper we present an easy to construct and use horizontal ladder-beam with a camera system on rails which can be used to evaluate both hindlimb and forelimb deficits in a single test. By slow motion videotape playback we were able to quantify and demonstrate foot misplacements which go beyond the recovery period usually seen using more conventional measures (i.e. footslips and footfaults). This convenient system provides a rapid and reliable method for recording and evaluating rat performance on any type of beam and may be useful for measuring sensorimotor recovery following brain injury.

Traumatic brain injury of the forelimb and hindlimb sensorimotor areas in the rat: physiological, histological and behavioral correlates.

This study characterizes physiological, histological and behavioral effects of traumatic brain injury (TBI) produced by a controlled pneumatic impactor striking the entire right sensorimotor cortex of the anesthetized rat. Damage to both the fore- and hindlimb sensorimotor areas resulted in a hemiparetic animal which allowed us to use four sensitive behavioral/neurological tests to track the recovery sequelae after injury. Initial experiments measured cardiovascular and respiratory effects after cortical impact which depressed the dura to varying depths. Both 0.5 mm and 1 mm cortical depressions produced a momentary decrease (P < 0.05) in mean arterial blood pressure (MABP) while cortical impacts to depths of 2 mm or 3 mm produced a momentary increase (P < 0.05) in MABP. Normotension was re-established within 30 s after the initial response at all injury levels. Respiratory rate was affected only following 3 mm cortical depressions. A 1 mm cortical depression appeared ideal in terms of minimal cardiorespiratory effects, low mortality and lasting behavioral effects. For behavioral and histologic studies, therefore, additional rats were injured by a 1 mm cortical impact and tested for 8 weeks after TBI using four behavioral tests. Injured rats displayed both fore- and hindlimb deficits up to 56 days while traversing a narrow beam (P < 0.001) and up to 28 days when crossing a pegged beam (P < 0.05). Forelimb deficits evaluated on a wire grid platform were evident for 28 days (P < 0.05). Forepaw preference measured in a non-test setting indicated a bias to use the unaffected forepaw for 35 days (P < 0.05). A biphasic pattern of functional recovery was seen on all tests. A period of rapid functional recovery lasting 7 to 10 days was followed by a slower period of functional recovery lasting many weeks. Possible meanings of this biphasic recovery are discussed as issues of behavioral compensation/adaptation versus true neural recovery. Eight weeks after TBI histological analyses indicated that axonal degeneration was present in the areas adjacent to the ipsilateral cortical injury site. Degenerating fibers also extended across the corpus callosum into the homologous area in the contralateral cortex and were seen in the ipsilateral striatum, somatosensory and motor thalamic nuclei and substantia nigra. Significant axonal degeneration occurred bilaterally around the deep cerebellar nuclei. Degenerating fibers extended into the folia and terminated in the cerebellar granule cell layer. Thus the entire sensorimotor control system appeared to have been affected by a cortical injury.

Some functional recovery and behavioral sparing occurs independent of task-specific practice after injury to the rat's sensorimotor cortex.

These experiments on rats evaluated whether recovery of competence in certain motor tests could be enhanced by practice begun soon after traumatic brain injury (TBI). Before TBI, rats were pre-trained to cross a flat and a pegged beam. Anesthetized animals received a right sensorimotor cortex TBI. One group began task-specific testing (flat and pegged beams) on day 1 after injury and repeated 13 times in 35 days by which time functional recovery occurred. Paw preference was evaluated eight times during the 35 day period, beginning the third day after injury. A second group of injured rats remained in their home cage without any testing for 35 days after injury. From day 35 they were tested 13 times over the next 35 days on both beam tests and eight times on the paw preference test. At day 35 those rats that remained in their home cage without testing (task-specific practice) performed as well on the flat beam as the rats that began testing 1 day after injury. By day 37, their third test day, the untested rats performed as well as the tested rats on the pegged beam. Paw preference was the same in both groups of rats. These results were compared to sham-operated controls. Post-injury performance as measured by these tests indicated that most of the recovery occurred without task-specific practice. However, task-specific practice was necessary to achieve optimum performance on both beam tests. This implies that neural reorganization occurred independent of any practice. Task specific practice served to 'fine tune' the rat's performance after 35 days.