Brain activation in the chronic phase of traumatic spinal cord injury.

STUDY DESIGN: Cross-sectional clinical study. OBJECTIVES: Plastic changes within cortical areas occur after traumatic spinal cord injury (TSCI). The aim of the study was to assess cortical activation in the chronic phase of TSCI using functional magnetic resonance imaging (fMRI). SETTING: Tartu University Hospital, Tartu, Estonia. METHODS: Ten right-handed patients with paraplegia and 18 healthy controls were studied by fMRI. Individuals performed simple flexion/extension of the right hand fingers and the right ankle during fMRI. The activation volumes, maximum t values (T max) and centres of gravity (COG) were calculated. RESULTS: The mean time since trauma was 1848±1046 days (range 388-4459). During hand movements, the volume of activation (VOA) in the contralateral primary motor cortex was significantly larger among the TSCI patients who did not recover compared with the controls (4112 vs 2777, P=0.02). The VOA did not enlarge during the ankle movements (2420 vs 1114, P=0.08). There was a significant relationship between the VOA in Brodmann area 4 (BA4) and American Spinal Injury Association motor score during hand movements (r=-0.67, P=0.03). A positive correlation was found during hand movements in the VOA of BA4 and time since injury (r=0.62, P=0.05). CONCLUSIONS: We found increased cortical activation in the chronic phase of thoraco-lumbar TSCI that may be caused by increased use of upper limbs.

Brain activation in the acute phase of traumatic spinal cord injury.

STUDY DESIGN: Prospective clinical study. BACKGROUND: The aim of the study was to investigate cortical reorganisation after traumatic spinal cord injury (TSCI) using functional magnetic resonance imaging (fMRI). SETTING: Tartu University Hospital, Tartu, Estonia. METHODS: We studied six right-handed tetraplegic TSCI patients at 1, 3 and 12 months after the injury and 12 age- and gender-matched healthy controls. Individuals performed simple test-rest cycles of flexion/extension of the right-hand fingers and flexion/extension of the right ankle during fMRI. The volumes of activation (VOA), maximum t-values, centres of gravity (COG) and weighted laterality indexes were calculated. RESULTS: There was no recovery of neurologic function in three patients and, according to the American Spinal Injury Association (ASIA) Impairment Scale the remaining three recovered. A positive correlation between the VOA in the primary motor cortex and the ASIA impairment scale (1 month: r=0.82, P=0.002; 3 Month: r=0.63, P=0.03; 12 Month: r=0.23, P=0.52) was found. The study also revealed a pattern of cortical activation that was increased among the patients who recovered (in Brodmann area 4 (BA 4), P=0.06; BA 1-2-3-5, P=0.08; BA 6, P=0.05). During the hand task there was an expansion of COG laterally, anteriorly and inferiorly among the patients who recovered. During the hand movement the cortical activation was less lateralised among the patients compared with the controls (P<0.05). CONCLUSION: Our study has found broadening of cortical activation and shift of COG during the first year after TSCI, depending on the recovery.

Survey of compliance with European acceptability criteria for HVL and AEC.

Half value layer (HVL) was measured for 226 general radiographic X-ray tube assemblies at 80 kV and for 53 dental X-ray tube assemblies at 70 kV, and evaluated by the previous (1997) and the new draft of European acceptability criteria (2009) for HVL as adopted from the IEC collateral standards. Fourteen per cent of the tested general radiography X-ray tube assemblies were subject to readjustment by the new criteria. In routine quality control tests, receptor entrance dose was estimated for 54 AEC systems by using post-exposure mAs values, taking into account the measured tube output at different tube potentials, HVL and estimated scattering for 10, 15 and 21 cm PMMA phantom. Receptor dose (third quartile) varied from 6.4 µGy at 60 kV to 3.8 µGy at 125 kV. The results correspond well to the draft criteria for maximum receptor dose of 10 µGy and for the patient thickness compensation.

Functional MRI of the cortical sensorimotor system in patients with hereditary spastic paraplegia.

OBJECTIVES: The study aimed to use functional magnetic resonance imaging to ascertain changes in sensorimotor system function in patients with hereditary spastic paraplegia and to correlate it with severity of spasticity and paresis. SETTING: Tartu University Hospital, Tartu, Estonia. METHODS: Nine patients with autosomal-dominant pure HSP and 14 age- and sex-matched healthy controls were investigated with a 1.5T fMRI scanner during flexion/extension of the right-hand fingers and right ankle. Images were analysed with a general linear model and Statistical Parametrical Mapping software. Highest Z-scores were identified from probability maps, and weighted laterality indices were calculated using combined bootstrap/histogram analysis; these were correlated with clinical severity of spasticity and paresis. RESULTS: During hand movements, clusters located in contralateral primary sensorimotor and premotor areas activated in both controls and patients. Bilateral activation occurred in the supplementary motor area, parietal operculum and cerebellum (predominantly ipsilateral). During the ankle task, bilateral activation was noted in the primary sensorimotor area, supplementary motor area and cerebellum. Activation clusters in HSP patients were smaller than those in controls in the sensorimotor area, especially during the ankle task, and more pronounced ipsilaterally in cerebellum both during hand and ankle motor tasks. Spasticity was significantly associated with contralateral activation in the sensory area and correlated negatively with the highest Z-scores in Brodmann areas 1-2-3 and 4. CONCLUSION: Our results suggest changes in cortical sensorimotor network function in patients with HSP compared with healthy subjects. Lower activation in patients might reflect damage to the corticospinal tract, be influenced by compensatory mechanisms, and/or be a reflection of neurorehabilitation.

Survey on performance assessment of cardiac angiography systems.

Advances in imaging technology have facilitated the development of increasingly complex interventional cardiac equipment. Consequently, there is a need for definitive equipment requirements. The aim of the study is to assess the performances of different cardiac angiographic systems. A questionnaire was sent to centres participating in SENTINEL Project to collect dosimetry data (typical entrance dose rate in fluoroscopy and imaging mode), image quality evaluations (low and high contrast resolutions) and KAP calibration factors. Results from this survey could contribute to the explanation of patient dose variability in angiographic cardiac procedures and to derive reference levels for cardiac angiographic equipment performance parameters.

Quality control measurements for fluoroscopy systems in eight countries participating in the SENTINEL EU coordination action.

Quality control (QC) is becoming increasingly important in relation to the introduction of digital medical imaging systems using X rays. It was, therefore, decided to organise and perform a trial on image quality and physical measurements. The SENTINEL toolkit for QC measurements of fluoroscopy systems containing equipment and instructions for their use in the assessment of dose and image quality circulated among participants in the trial. The participants reported on their results. In the present contribution, the impact of the trial on the selected protocols is presented. The Medical Physics and Bioengineering protocol appeared to be useful for QC, and also for digital systems. The protocol needs an additional section, or an addition to each section, to state compliance with the requirements. The circular cross-sections of the Leeds test objects need adaptation for rectangular flat panel detector (FPD) systems. Only one participant was able to perform the monitor test using MoniQA. This is due to the fact that assistance is required from the suppliers of the X-ray systems. This problem needs to be solved to apply MoniQA in practice.

Reference levels at European level for cardiac interventional procedures.

In interventional cardiology, a wide variation in patient dose for the same type of procedure has been recognised by different studies. Variation is almost due to procedure complexity, equipment performance, procedure protocol and operator skill. The SENTINEL consortium has performed a survey in nine european centres collecting information on near 2000 procedures, and a new set of reference levels (RLs) for coronary angiography and angioplasty and diagnostic electrophysiology has been assessed for air kerma-area product: 45, 85 and 35 Gy cm2, effective dose: 8, 15 and 6 mSv, cumulative dose at interventional reference point: 650 and 1500 mGy, fluoroscopy time: 6.5, 15.5 and 21 min and cine frames: 700 and 1000 images, respectively. Because equipment performance and set-up are the factors contributing to patient dose variability, entrance surface air kerma for fluoroscopy, 13 mGy min(-1), and image acquisition, 0.10 mGy per frame, have also been proposed in the set of RLs.

Staff dosimetry in interventional cardiology: survey on methods and level of exposure.

In interventional cardiac procedures, staff operates near the patient in a non-uniformly scattered radiation field. Consequently, workers may receive, over a period, relatively high radiation doses. The measurement of individual doses to personnel becomes critical due to the use of protective devices and, as a consequence of the large number of methods proposed to assess the effective dose, great variability in monitoring programmes is expected among European countries. SENTINEL consortium has conducted a survey on staff dosimetry methods and on the level of staff exposure in 12 European cardiac centres demonstrating the urgent need to harmonise dosimetry methods. From the dosimetry survey, constraint annual effective dose of 1.4 mSv and Hp(0.07) over the protective apron of 14 mSv are proposed for the optimisation the exposure the most-exposed operator.

Patient dose in interventional radiology: a European survey.

Patient doses for a few common fluoroscopy-guided procedures in interventional radiology (IR) (excluding cardiology) were collected from a few radiological departments in 13 European countries. The major aim was to evaluate patient doses for the basis of the reference levels. In total, data for 20 procedures for about 1300 patients were collected. There were many-fold variations in the number of IR equipment and procedures per population, in the entrance dose rates, and in the patient dose data (total dose area product or DAP, fluoroscopy time and number of frames). There was no clear correlation between the total DAP and entrance dose rate, or between the total DAP and fluoroscopy time, indicating that a number of parameters affect the differences. Because of the limited number of patients, preliminary reference levels were proposed only for a few procedures. There is a need to improve the optimisation of IR procedures and their definitions and grouping, in order to account for their different complexities.

Examining lactate in severe TBI using proton magnetic resonance spectroscopy.

PRIMARY OBJECTIVE: Clinical management of acute traumatic brain injury (TBI) has emphasized identification of secondary mechanisms of pathophysiology. An important objective in this study is to use proton magnetic resonance spectroscopy (pMRS) to examine early metabolic disturbance due to TBI. RESEARCH DESIGN: The current design is a case study with repeated measures. METHOD AND PROCEDURE: Proton magnetic resonance imaging was used to examine neurometabolism in this case of very severe brain trauma at 9 and 23 days post-injury. MRI was performed on a clinical 1.5 Tesla scanner. MAIN OUTCOMES AND RESULTS: These data also reveal that pMRS methods can detect lactate elevations in an adult surviving severe head trauma and are sensitive to changes in basic neurometabolism during the first month of recovery. CONCLUSIONS: The current case study demonstrates the sensitivity of pMRS in detecting metabolic alterations during the acute recovery period. The case study reveals that lactate elevations may be apparent for weeks after severe neurotrauma. Further work in this area should endeavour to determine the ideal time periods for pMRS examination in severe TBI as well as the ideal locations of data acquisition (e.g. adjacent or distal to lesion sites).

Axis II psychopathology in individuals with traumatic brain injury.

PRIMARY OBJECTIVES: To determine the frequency and nature of post-TBI personality disorders (PDs) in a community-based sample of individuals with TBI. RESEARCH DESIGN: One hundred individuals with TBI were administered a structural clinical interview to determine Axis II psychopathology. METHODS OF PROCEDURES: The Structured Clinical Interview for DSM-IV Personality Disorders, Clinician Version (SCID II) was used to determine 12 Axis II personality disorders. SCID II questions were modified so that symptom onset could be rated as occurring pre-injury vs. post-TBI. Data were analysed using student T-tests, chi-square analysis and one way analyses of variance. OUTCOMES AND RESULTS: Pre-TBI PDs were diagnosed in 24% of the sample; antisocial PD and obsessive-compulsive PD were the most common diagnoses. Post-TBI, 66% of the sample met criteria for at least one PD, with PDs independent of TBI severity, age at injury, and time since injury. The most common post-TBI PDs were: borderline, avoidant, paranoid, obsessive-compulsive and narcissistic. Men were more likely to be diagnosed with antisocial PD and narcissistic PD. Individuals with pre-TBI PDs were at greater risk of acquiring additional psychopathology post-TBI. Personality traits endorsed by more than 30% of the sample post-TBI reflected loss of self-confidence, attempts to cope with cognitive and interpersonal failures and negative affect. CONCLUSION: These findings argue against a specific TBI personality syndrome, but rather a diversity of personality disorders reflective of the persistent challenges and compensatory coping strategies developed by individuals post-TBI. Prospective need for clinical assessment, pro-active education and focused treatment approaches are discussed.

Axis I psychopathology in individuals with traumatic brain injury.

OBJECTIVES: To assess the incidence, comorbidity, and patterns of resolution of DSM-IV mood, anxiety, and substance use disorders in individuals with traumatic brain injury (TBI). DESIGN: The Structured Clinical Interview for DSM-IV Diagnoses (SCID) was utilized. Diagnoses were determined for three onset points relative to TBI onset: pre-TBI, post-TBI, and current diagnosis. Contrasts of prevalence rates with community-based samples, as well as chi-square analysis and analysis of variance were used. Demographics considered in analyses included gender, marital status, severity of injury, and years since TBI onset. SETTING: Urban, suburban, and rural New York state. PARTICIPANTS: 100 adults with TBI who were between the ages of 18 and 65 years and who were, on average, 8 years post onset at time of interview. MAIN OUTCOME MEASURES: SCID Axis I mood diagnoses of major depression, dysthymia, and bipolar disorder; anxiety diagnoses of panic disorder, obsessive-compulsive disorder (OCD), posttraumatic stress disorder (PTSD), generalized anxiety disorder (GAD), and phobia; and substance use disorders. RESULTS: Prior to TBI, a significant percentage of individuals presented with substance use disorders. After TBI, the most frequent Axis I diagnoses were major depression and select anxiety disorders (ie, PTSD, OCD, and panic disorder). Comorbidity was high, with 44% of individuals presenting with two or more Axis I diagnoses post TBI. Individuals without a pre-TBI Axis I disorder were more likely to develop post-TBI major depression and substance use disorders. Rates of resolution were similar for individuals regardless of previous psychiatric histories. Major depression and substance use disorders were more likely than were anxiety disorders to remit. CONCLUSION: TBI is a risk factor for subsequent psychiatric disabilities. The need for proactive psychiatric assessment and timely interventions in individuals post TBI is indicated.

Traumatic brain injury: family response and outcome.

Family outcome following traumatic brain injury has been the subject of investigation for nearly two decades. Researchers have reported on samples from Israel, Scotland, Denmark, England, and the United States. Cultural diversity as well as differences in design, assessment methods, injury characteristics, and definitions have contributed to difficulties establishing definitive conclusions. Findings indicate that patients' levels of emotional and personality disturbances are associated with levels of family disturbance, and are relatively more significant than physical disability. Undeniably, the long-term sequelae of injury have a long-term negative impact on families. Unfortunately, little has been done to establish the nature of family outcomes for patients younger than age 17, siblings, and less than severe injuries. Recent advances including development of valid measurement tools, definitions established through consensus, and multi-center collaborative research networks are promising and contribute to the likelihood of imminent progress.

Roles of gender, gonadectomy and estrous phase in the analgesic effects of intracerebroventricular morphine in rats.

Gender and gonadal function have previously been shown to influence the magnitude of analgesia following systemic morphine and opioid and nonopioid forms of swim analgesia with male rats displaying greater analgesia than female rats and gonadectomy reducing analgesic magnitude in both genders. These effects have been presumed to be centrally mediated. The present study evaluated the roles of gender, gonadectomy and estrous phase upon dose-response and time-response functions of analgesia following intracerebroventricular administration of morphine as measured by the tail-flick and jump tests. Sham-operated male rats displayed significantly greater magnitudes of peak and total analgesia following central morphine than sham-operated female rats on both nociceptive measures. This striking effect was reflected both in terms of magnitude and ED50; while male rats displayed near-maximal analgesia at a 5 micrograms dose of morphine, female rats displayed moderate analgesia at doses as high as 40 micrograms of morphine. Castration produced small, but significant reductions in the magnitude of central morphine analgesia; the ED50 of morphine analgesia, however, was not changed. Although female rats in either proestrous or estrous displayed significantly greater magnitude of analgesia than ovariectomized rats or rats in a combined met-/di-estrous phase at some doses, the ED50 of morphine analgesia was not significantly altered as functions of estrous phase or ovariectomy. The interaction of opiate receptors and gonadal steroid receptors is considered as one possible determinant of gender differences observed in the magnitude and potency of central morphine analgesia.

Gender determinants of opioid mediation of swim analgesia in rats.

Continuous cold-water swims (CCWS) and intermittent cold-water swims (ICWS) elicit respective nonopioid and opioid analgesic responses in adult male rats. The present experiment evaluated whether gender differences were observed in naloxone's (14 mg/kg, SC) ability to alter differentially CCWS and ICWS analgesia on the tail-flick and jump tests in age-matched and weight-matched intact rats and in gonadectomized rats. CCWS analgesia was unaffected by naloxone on either test in age-matched males and females. Naloxone significantly reduced ICWS analgesia on the tail-flick (45%) and jump (37%) tests in intact males, but not age-matched females. Naloxone significantly reversed ICWS analgesia in weight-matched males on the tail-flick (1-14 mg/kg, 30-32%) and jump (14 mg/kg, 31%) tests. Naloxone also significantly reduced ICWS analgesia on the tail-flick (32%) and jump (41%) tests in castrated males, but not ovariectomized females. Changes in swim hypothermia could not account for the above effects. These data indicate gender differences in naloxone's differential modulation of swim analgesia, and reflect further differences in pain-inhibitory responses as a function of gender.

Yohimbine potentiates cold-water swim analgesia: re-evaluation of a noradrenergic role.

Continuous cold-water swims (CCWS) elicit a nonopioid and neurohormonal analgesia which displays adaptation. The norepinephrine (NE) system has been implicated since parallel alterations in NE occur following acute and repeated CCWS exposure, and since CCWS analgesia is reduced by locus coeruleus lesions and is potentiated by clonidine and desipramine. The present study evaluated the effects of the alpha-2 NE receptor antagonist, yohimbine upon CCWS (2 degrees C for 3.5 min) analgesia on the jump and tail-flick tests, CCWS hypothermia, and basal nociceptive and thermoregulatory measures in rats. Yohimbine (0.1-2.0 mg/kg, IP) dose-dependently increased basal jump thresholds and potentiated CCWS analgesia: these effects appeared to be additive. Yohimbine potentiated CCWS analgesia on the tail-flick test without altering basal latencies. Yohimbine failed to alter either CCWS hypothermia or basal thermoregulation. Since yohimbine and clonidine, an alpha-2 NE receptor antagonist and agonist respectively, similarly potentiate CCWS analgesia, it appears that NE effects are orthoganol to the intrinsic system mediating CCWS.

Modulation of gender-specific effects upon swim analgesia in gonadectomized rats.

Gender-specific effects have been observed for continuous and intermittent cold-water swim (CCWS and ICWS respectively) analgesia: analgesic magnitudes following CCWS and ICWS are significantly smaller in female rats than in age-matched and weight-matched male rats. The present study evaluated the role of gonadal status in these gender-specific effects by examining CCWS and ICWS analgesia, hypothermia and activity in intact and gonadectomized rats. Following confirmation of the original gender-specific effects on the tail-flick and jump tests, it was found that both castration and ovariectomy significantly reduced CCWS and ICWS analgesia. Indeed, castrated males displayed similar magnitudes of analgesia as intact females. The more marked hypothermia observed in intact females indicated that this variable failed to account for the analgesic gender-specific effects. The reduced hypothermia following gonadectomy also failed to account for the analgesic changes. The increased activity during ICWS, but not CCWS following gonadectomy also did not account for the analgesic changes. These data suggest that gonadal steroids normally appear to facilitate these stress-related analgesic responses.