Clinical progression and outcome of dysphagia following paediatric traumatic brain injury: a prospective study

Objectives : To provide a preliminary clinical profile of the resolution and outcomes of oral-motor impairment and swallowing function in a group of paediatric dysphagia patients post-traumatic brain injury (TBI). To document the level of cognitive impairment parallel to the return to oral intake, and to investigate the correlation between the resolution of impaired swallow function versus the resolution of oral-motor impairment and cognitive impairment. Participants : Thirteen children admitted to an acute care setting for TBI. Main outcome measures : A series of oral-motor (Verbal Motor Production Assessment for Children, Frenchay Dysarthria Assessment, Schedule for Oral Motor Assessment) and swallowing (Paramatta Hospital's Assessment for Dysphagia) assessments, an outcome measure for swallowing (Royal Brisbane Hospital's Outcome Measure for Swallowing), and a cognitive rating scale (Rancho Level of Cognitive Functioning Scale). Results : Across the patient group, oral-motor deficits resolved to normal status between 3 and 11 weeks post-referral (and at an average of 12 weeks post-injury) and swallowing function and resolution to normal diet status were achieved by 3-11 weeks post-referral (and at an average of 12 weeks post-injury). The resolution of dysphagia and the resolution of oral-motor impairment and cognitive impairment were all highly correlated. Conclusion : The provision of a preliminary profile of oral-motor functioning and dysphagia resolution, and data on the linear relationship between swallowing impairment and cognition, will provide baseline information on the course of rehabilitation of dysphagia in the paediatric population post-TBI. Such data will contribute to more informed service provision and rehabilitation planning for paediatric patients post-TBI.

Caveolins in the repair phase of acute renal failure after oxidative stress

Ischaemia-reperfusion and toxic injury are leading causes of acute renal failure (ARF). Both of these injury initiators use secondary mediators of damage in oxygen-derived free radicals. Several recent publications about ischaemia-reperfusion and toxin-induced ARF have indicated that plasma membrane structures called caveolae, and their proteins, the caveolins, are potential participants in protecting or repairing renal tissues. Caveolae and caveolins have previously been ascribed many functions, a number of which may mediate cell death or survival of injured renal cells. This review proposes possible pathophysiological mechanisms by which altered caveolin-1 expression and localization may affect renal cell survival following oxidative stress.

The role of the complement system in ischemia-reperfusion injury

Ischemia-reperfusion (I/R) injury is a common clinical event with the potential to seriously affect, and sometimes kill, the patient. Interruption of blood supply causes ischemia, which rapidly damages metabolically active tissues. Paradoxically, restoration of blood flow to the ischemic tissues initiates a cascade of pathology that leads to additional cell or tissue injury. I/R is a potent inducer of complement activation that results in the production of a number of inflammatory mediators. The use of specific inhibitors to block complement activation has been shown to prevent local tissue injury after I/R. Clinical and experimental studies in gut, kidney, limb, and liver have shown that I/R results in local activation of the complement system and leads to the production of the complement factors C3a, C5a, and the membrane attack complex. The novel inhibitors of complement products may find wide clinical application because there are no effective drug therapies currently available to treat I/R injuries.

Differential expression of muscle damage in humans following acute fast and slow velocity eccentric exercise

We sought to determine if the velocity of an acute bout of eccentric contractions influenced the duration and severity of several common indirect markers of muscle damage. Subjects performed 36 maximal fast (FST, n=8: 3.14 rad center dot s(-1)) or slow (SLW, n=7: 0.52 rad center dot s(-1)) velocity isokinetic eccentric contractions with the elbow flexors of the non-dominant arm. Muscle soreness, limb girth, plasma creatine kinase (CK) activity, isometric torque and concentric and eccentric torque at 0.52 and 3.14 rad center dot s(-1) were assessed prior to and for several days following the eccentric bout. Peak plasma CK activity was similar in SLW (4030 +/- 1029 U center dot l(-1)) and FST (5864 +/- 2664 U center dot l(-1)) groups, (p > 0.05). Both groups experienced similar decrement in all strength variables during the 48 hr following the eccentric bout. However, recovery occurred more rapidly in the FST group during eccentric (0.52 and 3.14 rad center dot s(-1)) and concentric (3.14 rad center dot s(-1)) post-testing. The severity of muscle soreness was similar in both groups. However, the FST group experienced peak muscle soreness 48 hr later than the SLW group (24 hr vs. 72 hr). The SLW group experienced a greater increase in upper arm girth than the FST group 20 min, 24 hr and 96 hr following the eccentric exercise bout. The contraction velocity of an acute bout of eccentric exercise differentially influences the magnitude and time course of several indirect markers of muscle damage.

Six-month outcome for dysphagia following traumatic brain injury: Radiological assessment

The coexistence of a swallowing impairment, or dysphagia, can severely impact upon the medical condition and recovery of a child with traumatic brain injury (TBI; Logemann, Pepe, & Mackay, 1994). Despite this fact, there is limited data that provide evidence of the progression or outcome of dysphagia in the pediatric population post-TBI (Rowe, 1999). The present study aimed to (1) provide a prospective radiologically based profile of swallowing outcome and (2) determine the clinical significance of any persistent physiological swallowing deficits by investigating the presence/absence of any coexistent respiratory complications. Seven children with moderate/severe TBI were evaluated via an initial videofluoroscopic swallowing assessment (VFSS) at an average of 24.1 days postinjury, during the acute phase of management. A follow-up VFSS was conducted at an average of 7 months, 3 weeks postinjury. The physiological impairment, swallowing safety, swallowing efficiency, and functional swallowing outcomes of the acute phase post-TBI were compared with reassessment results at 6 months post-TBI. The presence/absence of lower respiratory tract infection/respiratory complications in the past 6 months postinjury were recorded.VFSS revealed a number of residual physiological oropharyngeal swallowing impairments and reduced swallowing efficiency. However, all participants presented with clinically safe and functional swallowing outcomes at 6 months post-TBI, with no recent history of respiratory complication. This study indicates good functional swallowing and respiratory outcomes for patients at 6-months post-TBI despite the presence of persistent physiological swallowing impairment.

Physical and psychological factors predict outcome following whiplash injury

Predictors of outcome following whiplash injury are limited to socio-demographic and symptomatic factors, which are not readily amenable to secondary and tertiary intervention. This prospective study investigated the predictive capacity of early measures of physical and psychological impairment on pain and disability 6 months following whiplash injury. Motor function (ROM; kinaesthetic sense; activity of the superficial neck flexors (EMG) during cranio-cervical flexion), quantitative sensory testing (pressure, thermal pain thresholds, brachial plexus provocation test), sympathetic vasoconstrictor responses and psychological distress (GHQ-28, TSK, IES) were measured in 76 acute whiplash participants. The outcome measure was Neck Disability Index scores at 6 months. Stepwise regression analysis was used to predict the final NDI score. Logistic regression analyses predicted membership to one of the three groups based on final NDI scores (< 8 recovered, 10-28 mild pain and disability, > 30 moderate/severe pain and disability). Higher initial NDI score (1.007-1.12), older age (1.03-1.23), cold hyperalgesia (1.05-1.58), and acute post-traumatic stress (1.03-1.2) predicted membership to the moderate/severe group. Additional variables associated with higher NDI scores at 6 months on stepwise regression analysis were: ROM loss and diminished sympathetic reactivity. Higher initial NDI score (1.03-1.28), greater psychological distress (GHQ-28) (1.04-1.28) and decreased ROM (1.03-1.25) predicted subjects with persistent milder symptoms from those who fully recovered. These results demonstrate that both physical and psychological factors play a role in recovery or non-recovery from whiplash injury. This may assist in the development of more relevant treatment methods for acute whiplash. (c) 2004 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Renal endothelial dysfunction and impaired autoregulation after ischemia-reperfusion injury result from excess nitric oxide

Endothelial dysfunction in ischemic acute renal failure (IARF) has been attributed to both direct endothelial injury and to altered endothelial nitric oxide synthase ( eNOS) activity, with either maximal upregulation of eNOS or inhibition of eNOS by excess nitric oxide ( NO) derived from iNOS. We investigated renal endothelial dysfunction in kidneys from Sprague-Dawley rats by assessing autoregulation and endothelium-dependent vasorelaxation 24 h after unilateral ( U) or bilateral ( B) renal artery occlusion for 30 (U30, B30) or 60 min (U60, B60) and in sham-operated controls. Although renal failure was induced in all degrees of ischemia, neither endothelial dysfunction nor altered facilitation of autoregulation by 75 pM angiotensin II was detected in U30, U60, or B30 kidneys. Baseline and angiotensin II-facilitated autoregulation were impaired, methacholine EC50 was increased, and endothelium-derived hyperpolarizing factor ( EDHF) activity was preserved in B60 kidneys. Increasing angiotensin II concentration restored autoregulation and increased renal vascular resistance ( RVR) in B60 kidneys; this facilitated autoregulation, and the increase in RVR was abolished by 100 mu M furosemide. Autoregulation was enhanced by N-omega-nitro-L-arginine methyl ester. Peri-ischemic inhibition of inducible NOS ameliorated renal failure but did not prevent endothelial dysfunction or impaired autoregulation. There was no significant structural injury to the afferent arterioles with ischemia. These results suggest that tubuloglomerular feedback is preserved in IARF but that excess NO and probably EDHF produce endothelial dysfunction and antagonize autoregulation. The threshold for injury-producing, detectable endothelial dysfunction was higher than for the loss of glomerular filtration rate. Arteriolar endothelial dysfunction after prolonged IARF is predominantly functional rather than structural.

Physical and psychological factors maintain long-term predictive capacity post-whiplash injury

Higher initial levels of pain and disability, older age, cold hyperalgesia, impaired sympathetic vasoconstriction and moderate post-traumatic stress symptoms have been shown to be associated with poor outcome 6 months following whiplash injury. This study prospectively investigated the predictive capacity of these variables at a long-term follow-up. Sixty-five of an initial cohort of 76 acutely injured whiplash participants were followed to 2-3 years post-accident. Motor function (ROM; kinaesthetic sense; activity of the superficial neck flexors (EMG) during cranio-cervical flexion), quantitative sensory testing (pressure, thermal pain thresholds and brachial plexus provocation test), sympathetic vasoconstrictor responses and psychological distress (GHQ-28, TSK and IES) were measured. The outcome measure was Neck Disability Index (NDI) scores. Participants with ongoing moderate/severe symptoms at 2-3 years continued to manifest decreased ROM, increased EMG during cranio-cervical flexion, sensory hypersensitivity and elevated levels of psychological distress when compared to recovered participants and those with milder symptoms. The latter two groups showed only persistent deficits in cervical muscle recruitment patterns. Higher initial NDI scores (OR 1.00-1.1), older age (OR 1.00-1.13), cold hyperalgesia (OR 1.1-1.13) and post-traumatic stress symptoms (OR 1.03-1.2) remained significant predictors of poor outcome at long-term follow-up (r(2) = 0.56). The robustness of these physical and psychological factors suggests that their assessment in the acute stage following whiplash injury will be important. (c) 2006 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Perinatal outcomes with laser surgery for twin-twin transfusion syndrome

The aim of this tertiary hospital-based cohort study was to determine and compare perinatal outcome and neonatal morbidities of pregnancies with twin-twin transfusion syndrome (TTTS) before and after the introduction of a treatment program with laser ablation of placental communicating vessels. Twenty-seven pregnancies with Stage II-IV TTTS treated with amnioreduction were identified (amnioreduction group). The data were compared with that obtained from the first 31 pregnancies with Stage II-IV TTTS managed with laser ablation of placental communicating vessels (laser group). Comparisons were made for perinatal survival and neonatal morbidities including abnormalities on brain imaging. The median gestation at therapy was similar between the two groups (20 vs. 21 weeks, p = .24), while the median gestation at delivery was significantly greater in the laser treated group (34 vs. 28 weeks, p = .002). The perinatal survival rate was higher in the laser group (77.4% vs. 59.3%, p = .03). Neonatal morbidities including acute respiratory distress, chronic lung disease, requirement for ventilatory assistance, patent ductus arteriosus, hypotension, and oliguric renal failure had a lower incidence in the laser group. On brain imaging, ischemic brain injury was seen in 12% of the amnioreduction group and none of the laser group of infants (p = .01). In conclusion, these findings indicate that perinatal outcomes are improved with less neonatal morbidity for monochorionic pregnancies with severe TTTS treated by laser ablation of communicating placental vessels when compared to treatment by amnioreduction.

Segmental lung lobe torsion in a 7-week-old Pug

Case summary: A 7-week-old, intact female Pug was referred with an acute history of expiratory dyspnea, tachypnea, and pyrexia. Radiologic evaluation revealed bilateral pleural effusion and a poorly demarcated area of soft tissue opacity cranial to the heart. The presence of air bronchograms in the cranial lung lobes suggested alveolar parenchymal pathology consistent with pulmonary edema, congestion, or cellular infiltration. Exploratory thoracotomy revealed a segmental torsion of the left cranial lung lobe. The affected lobe was removed and the puppy recovered uneventfully. Unique information: Lung lobe torsion tends to occur more frequently in mature large breed dogs at a mean age of 3 years. The age, breed, and segmental nature of the torsion in the reported case are contrary to most of the previously documented cases of lung lobe torsion. To the authors' knowledge, this is the first report of lung lobe torsion in a 7-week-old dog.

Rapid Atrophy of the Lumbar Multifidus Follows Experimental Disc or Nerve Root Injury.

Study Design. Experimental study of muscle changes after lumbar spinal injury. Objectives. To investigate effects of intervertebral disc and nerve root lesions on cross-sectional area, histology and chemistry of porcine lumbar multifidus. Summary of Background Data. The multifidus cross-sectional area is reduced in acute and chronic low back pain. Although chronic changes are widespread, acute changes at 1 segment are identified within days of injury. It is uncertain whether changes precede or follow injury, or what is the mechanism. Methods. The multifidus cross-sectional area was measured in 21 pigs from L1 to S1 with ultrasound before and 3 or 6 days after lesions: incision into L3 - L4 disc, medial branch transection of the L3 dorsal ramus, and a sham procedure. Samples from L3 to L5 were studied histologically and chemically. Results. The multifidus cross-sectional area was reduced at L4 ipsilateral to disc lesion but at L4 - L6 after nerve lesion. There was no change after sham or on the opposite side. Water and lactate were reduced bilaterally after disc lesion and ipsilateral to nerve lesion. Histology revealed enlargement of adipocytes and clustering of myofibers at multiple levels after disc and nerve lesions. Conclusions. These data resolve the controversy that the multifidus cross-sectional area reduces rapidly after lumbar injury. Changes after disc lesion affect 1 level with a different distribution to denervation. Such changes may be due to disuse following reflex inhibitory mechanisms.

Psychometric assessment of recovery from mild traumatic brain injury

The Rapid Screen of Concussion (RSC) is a brief psychometric test battery, designed to provide a functional criterion to aid clinical diagnosis of mild traumatic brain injury (mTBI). The present research aimed to examine the utility of this instrument for assessing recovery after mTBI. Three studies were conducted. In Study 1, Discriminant Function Analysis was performed to determine how well the RSC differentiated uninjured controls (N¼16), from mTBI patients (N¼22) and moderate to severe TBI patients (N¼14), several months post-injury. As predicted, moderate to severe TBI patients achieved lower scores than the mTBI and control groups. The RSC also successfully differentiated between each of the diagnostic groups, yielding an overall correct classification rate of 75%. Study 2 examined the predictive utility of the RSC in the mTBI sample (N¼22). Acute injury performance on the RSC was correlated with post-injury scores at an average of 5.5 months post-injury. Statistically significant partial correlation coefficients (r¼0.53r¼0.80) were found for each of the subtests, showing that low acute RSC scores were predictive of poor recovery scores on the RSC after mTBI. In the third study, Reliable Change Indices were calculated on the RSC subtests to examine individual patterns of recovery from mTBI. While 17 of the 23 participants made a significant improvement on their acute injury DSST scores (74%), only 13 of 25 made a significant improvement on the Rapid Sentence Judgement Test (52%), highlighting differential recovery of function, and challenging the notion of full recovery from mTBI within 3 months. These overall results offer support for the construct and predictive validity of the RSC and demonstrate that inexpensive tests of brain function may be useful for managing mTBI acutely for prognosis.