A systematic review of the measures that have been used to assess surface characteristics in relation to their impact on walking and falling.

We investigated whether an impediment to progress in understanding the environmental factors that cause falls may be the difficulty in comparing results across studies because walking surfaces are poorly defined and underspecified. We conducted a systematic review of 384 studies from 370 articles that tested how different surfaces influenced human walking and falling. For each study, we report which categories of surfaces were used (indoor, outdoor, treadmill, virtual reality and qualitative), the nature of each surface (stairs, slopes, slippery, compliant, rough or default) and how information about each surface was measured. We found that minimal information was provided for many surfaces, making it impossible to meaningfully compare results for different types of surfaces across studies. We conclude that most published studies of walking and falling provide insufficient data to describe the surfaces that they used and we provide recommendations about how to improve the reporting of walking surfaces.

Long-Term Health-Related Quality of Life Outcomes Following Thyroid Surgery for Malignant or Benign Disease: Deficits Persist in Cancer Survivors Beyond Five Years.

BACKGROUND: Thyroid cancer diagnoses are increasing and treatment can lead to significant morbidity. Long-term health-related quality of life (HRQoL) in thyroid cancer is understudied and lacks reference populations. This study compares long-term HRQoL between patients with thyroid cancer or benign disease, following thyroid surgery. METHODS: Patients undergoing thyroidectomy between 2000 and 2017 were identified from a pathology database. 696 participants (278 malignant, 418 benign) were invited to complete a validated disease-specific HRQoL tool, City of Hope-Thyroid Version. Propensity scores were used to adjust for demographic and clinical differences between cohorts. RESULTS: 206 patients (102 malignant, 104 benign), 71% female, returned surveys a median of 6.5 (range 1-19) years after thyroidectomy. Of the cancer cohort, 95% had differentiated thyroid cancer and 83% remained disease-free. There were no significant differences in overall HRQoL scores between groups. In comparison to the benign cohort, cancer patients showed a significant detriment in the social subdomain score (OR 0.10-0.96, p = 0.017) but not in other subdomains (physical, psychological, spiritual). Female gender, increasing BMI and cancer recurrence were significantly associated with decreased overall HRQoL. Compared to the benign cohort, cancer patients reported more personal and family distress associated with diagnosis and treatment, increased future uncertainty, poorer concentration and greater financial burden. CONCLUSION: Although no difference in overall HRQoL was found between patients undergoing thyroidectomy for benign or malignant disease, detriments in social well-being may persist many years after surgery. Thyroid cancer patients and their families may benefit from increased supports around the time of diagnosis and treatment.

Biomechanical adaptation to post-stroke visual field loss: a systematic review.

BACKGROUND: Homonymous visual field defects represent the most frequent type of visual field loss after stroke, affecting nearly 30% of individuals with unilateral post-chiasmal brain damage. This review aimed to gather the available evidence on the biomechanical changes to visual field loss following stroke. METHODS: A systematic review was conducted inclusive of randomised controlled trials, cohort studies, before-after studies and case-controlled studies. Studies including adult and paediatric participants that investigated eye, head, or body movements in post-stroke visual field loss during visual exploration tasks were included. Search terms included a range of MESH terms as well as alternative terms relating to stroke, visual field loss, hemianopia, visual functions and scanning behaviour. Articles were selected by two authors independently. Data were extracted by one author and verified by a second. All included articles were assessed for risk of bias using checklists appropriate to the study design. RESULTS: Thirty-six articles (1123 participants) were included in the overall review (Kappa 0.863) and categorised into simulated or true visual field loss (typically hemianopia). Seven studies identified the biomechanical alterations to simulated hemianopia compared to normal performance. Twenty-nine studies detailed eye, head and body movement parameters in true hemianopia. Hemianopic participants and healthy adults with simulated hemianopia differed significantly from controls in various fixation and saccade parameters as indicated by increased number and duration of fixations, number and duration of saccades and scan path length with shorter mean saccadic amplitude. Under simulated hemianopia, participants were consistently biased towards the sighted visual field while gaze behaviour in true hemianopia was biased in the direction of the blind hemifield. CONCLUSIONS: There is considerable evidence on the altered eye movements that occur in true hemianopia and in healthy adults with simulated hemianopia. Successful performance in naturalistic tasks of visual exploration appears to be related to compensatory mechanisms of visual exploratory behaviour, namely, an increase in the amplitude and peak velocity of saccades, widening horizontally the distribution of eye movements, and a shift of the overall distribution of saccades into the blind field. This review highlights the lack of studies reporting head and other body movement parameters in hemianopia. Further studies with robust methodology and large sample sizes involving participants with post-stroke visual field loss are needed. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020194403.

Bi-national Review of Phaeochromocytoma Care: Is ICU Admission Always Necessary?

BACKGROUND: Post-operative management after phaeochromocytoma resection includes monitoring of blood pressure and blood sugar, and vigilance for haemorrhage. Guidelines recommend 24 h of continuous blood pressure monitoring, usually necessitating HDU/ICU admission. We hypothesised that most patients undergoing phaeochromocytoma resection do not require post-operative HDU/ICU admission. We aim to describe current Australian and New Zealand perioperative management of phaeochromocytoma and determine whether it is safe to omit HDU/ICU care for most patients. METHODS: We collected retrospective data on patients undergoing excision of phaeochromocytoma in 12 centres around Australia and New Zealand between 2007 and 2019. Data collected included preoperative medical management, anaesthetic management, vasopressor support, HDU/ICU admission and complications. RESULTS: A total of 223 patients were included in the study, 173 (77%) of whom were admitted to HDU/ICU post-operatively. The group of patients treated in ICU was similar to the group of patients treated on the ward in terms of demographic and tumour characteristics, and there were significant differences in the proportion of patients admitted to HDU/ICU between centres. Of patients admitted to ICU, 71 (41%) received vasopressor support. This was weaned within 24 h in 55 (77%) patients. Patients with larger tumours (> 6 cm) and a transfusion requirement are more likely to require prolonged inotropic support. Among patients admitted to the ward, there were no complications that required escalation of care. CONCLUSIONS: Although not widespread practice in Australia and New Zealand, it appears safe for the majority of patients undergoing minimally invasive resection of phaeochromocytoma to be admitted to the ward post-operatively.

Keep your head down: Maintaining gait stability in challenging conditions.

BACKGROUND: Peripheral vision often deteriorates with age, disrupting our ability to maintain normal locomotion. Laboratory based studies have shown that lower visual field loss, in particular, is associated with changes in gaze and gait behaviour whilst walking and this, in turn, increases the risk of falling in the elderly. Separately, gaze and gait behaviours change and fall risk increases when walking over complex surfaces. It seems probable, but has not yet been established, that these challenges to stability interact. RESEARCH QUESTION: How does loss of the lower visual field affect gaze and gait behaviour whilst walking on a variety of complex surfaces outside of the laboratory? Specifically, is there a synergistic interaction between the effects on behaviour of blocking the lower visual field and increased surface complexity? METHODS: We compared how full vision versus simulated lower visual field loss affected a diverse range of behavioural measures (head pitch angle, eye angle, muscle coactivation, gait speed and walking smoothness as measured by harmonic ratios) in young participants. Participants walked over a range of surfaces of different complexity, including pavements, grass, steps and pebbles. RESULTS: In both full vision and blocked lower visual field conditions, surface complexity influenced gaze and gait behaviour. For example, more complex surfaces were shown to be associated with lowered head pitch angles, increased leg muscle coactivation, reduced gait speed and decreased walking smoothness. Relative to full vision, blocking the lower visual field caused a lowering of head pitch, especially for more complex surfaces. However, crucially, muscle coactivation, gait speed and walking smoothness did not show a significant change between full vision and blocked lower visual field conditions. Finally, head pitch angle, muscle coactivation, gait speed and walking smoothness were all correlated highly with each other. SIGNIFICANCE: Our study showed that blocking the lower visual field did not significantly change muscle coactivation, gait speed or walking smoothness. This suggests that young people cope well when walking with a blocked lower visual field, making minimal behavioural changes. Surface complexity had a greater effect on gaze and gait behaviour than blocking the lower visual field. Finally, head pitch angle was the only measure that showed a significant synergistic interaction between surface complexity and blocking the lower visual field. Together our results indicate that, first, a range of changes occur across the body when people walk over more complex surfaces and, second, that a relatively simple behavioural change (to gaze) suffices to maintain normal gait when the lower visual field is blocked, even in more challenging environments. Future research should assess whether young people cope as effectively when several impairments are simulated, representative of the comorbidities found with age.

Physical and perceptual measures of walking surface complexity strongly predict gait and gaze behaviour.

BACKGROUND: Walking surfaces vary in complexity and are known to affect stability and fall risk whilst walking. However, existing studies define surfaces through descriptions only. OBJECTIVE: This study used a multimethod approach to measure surface complexity in order to try to characterise surfaces with respect to locomotor stability. METHODS: We assessed how physical measurements of walking surface complexity compared to participant's perceptual ratings of the effect of complexity on stability. Physical measurements included local slope measures from the surfaces themselves and shape complexity measured using generated surface models. Perceptual measurements assessed participants' perceived stability and surface roughness using Likert scales. We then determined whether these measurements were indicative of changes to stability as assessed by behavioural changes including eye angle, head pitch angle, muscle coactivation, walking speed and walking smoothness. RESULTS: Physical and perceptual measures were highly correlated, with more complex surfaces being perceived as more challenging to stability. Furthermore, complex surfaces, as defined from both these measurements, were associated with lowered head pitch, increased muscle coactivation and reduced walking smoothness. SIGNIFICANCE: Our findings show that walking surfaces defined as complex, based on physical measurements, are perceived as more challenging to our stability. Furthermore, certain behavioural measures relate better to these perceptual and physical measures than others. Crucially, for the first time this study defined walking surfaces objectively rather than just based on subjective descriptions. This approach could enable future researchers to compare results across walking surface studies. Moreover, perceptual measurements, which can be collected easily and efficiently, could be used as a proxy for estimating behavioural responses to different surfaces. This could be particularly valuable when determining risk of instability when walking for individuals with compromised stability.

Look out: an exploratory study assessing how gaze (eye angle and head angle) and gait speed are influenced by surface complexity.

BACKGROUND: Most research investigating the connection between walking and visual behaviour has assessed only eye movements (not head orientation) in respect to locomotion over smooth surfaces in a laboratory. This is unlikely to reflect gaze changes found over the complex surfaces experienced in the real world, especially given that eye and head movements have rarely been assessed simultaneously. RESEARCH QUESTION: How does gaze (eye and head) angle and gait speed change when walking over surfaces of different complexity? METHODS: In this exploratory study, we used a mobile eye tracker to monitor eye movements and inertia measurement unit sensors (IMUs) to measure head angle whilst subjects (n = 11) walked over surfaces with different complexities both indoors and outdoors. Gait speed was recorded from ankle IMUs. RESULTS: Overall, mean gaze angle was lowest over the most complex surface and this surface also elicited the slowest mean gait speed. The head contributed increasingly to the lowering of gaze with increased surface complexity. Less complex surfaces showed no significant difference between gaze and gait behaviour. SIGNIFICANCE: This study supports previous research showing that increased surface complexity is an important factor in determining gaze and gait behaviour. Moreover, it provides the novel finding that head movements provide important contributions to gaze location. Our future research aims are to further assess the role of the head in determining gaze location during locomotion across a greater range of complex surfaces to determine the key surface characteristics that influence gaze during gait.

Same-day versus staged anterior-posterior spinal surgery in a neuromuscular scoliosis population: the evaluation of medical complications.

The medical complications occurring in 29 patients with neuromuscular spinal deformity undergoing two-stage anterior-posterior spinal fusion ("staged") were compared with 16 neuromuscular patients undergoing single-stage anterior-posterior spinal fusion ("same day"). Thirty-six (124%) major and minor medical complications occurred postoperatively in the staged patients, whereas 14 (88%) major or minor complication were present in same-day surgery patients. Thirty-five percent of staged patients had no complications, whereas 63% of same-day patients were without complications. Associated findings comparing the two-stage procedure to the single-stage surgery included operative and anesthesia time increase, increased blood-volume loss, increased blood transfusion, decreased nutritional parameters, and longer hospital stays. With either approach, there is the risk of significant complications in this vulnerable population.

Abnormalities of the neonatal brain: MR imaging. Part I. Intracranial hemorrhage.

The authors prospectively evaluated 82 neonates, ranging in gestational age from 29 to 44 weeks postconception, with magnetic resonance (MR) imaging at 0.6 T. Twenty-two cases of hemorrhage in 15 infants were identified. Ultrasound (US) and computed tomography (CT) were superior to MR in the first few days after parenchymal hemorrhage, since at this time lesions were apparent on only T2-weighted images. After the first 3 days, MR was the single best modality because (a) hemorrhage on CT became imperceptible in the 2d week, whereas the high signal of hemorrhage on MR persisted for 2-11 weeks; (b) MR permitted rough dating of hemorrhage according to changes in signal intensity; and (c) MR was superior in identifying subdural or epidural hemorrhage. Because of the nonspecificity and restricted field of view of US and the inability of CT to depict hemorrhage after 7-10 days, the authors conclude that MR significantly improves the detection of intracranial hemorrhage in neonates.

Abnormalities of the neonatal brain: MR imaging. Part II. Hypoxic-ischemic brain injury.

Eighty-five infants, 82 of whom were 29-44 weeks postconceptional age, were imaged with a 0.6-T magnet. Eight infants had cerebral infarction. In premature neonates with very water, low-intensity white matter on T1-weighted images, ultrasound was better than both computed tomography and magnetic resonance (MR) imaging in depicting parenchymal changes of infarction or edema. However, after 37 weeks gestation, MR imaging was superior. Cerebral atrophy, present in seven infants, was consistent with subarachnoid space widths of 7 mm or more, or subarachnoid space widths of 5-6 mm with ventricular/brain ratios of 0.36 or greater. Delayed myelination was seen in a total of 18 infants with histories of hypoxic-ischemic insult. MR imaging shows promise in the neonatal period. It facilitates recognition of infarcts in full-term infants and may be used to predict abnormal neurologic outcome in infants who have initial delayed myelination.

Developmental features of the neonatal brain: MR imaging. Part I. Gray-white matter differentiation and myelination.

To establish the normal appearance of the neonatal brain, 51 neonates, 29-42 weeks postconception, underwent magnetic resonance (MR) imaging with a 0.6-T magnet in a prospective study. T1-weighted images were used to devise stages for the appearance of gray-white matter differentiation and extent of myelination. The results show that from 29 to 42 weeks postconception, changes in gray-white matter differentiation and myelination follow the stages in an orderly and predictable fashion. Changes in white matter intensity appear related to progressive decrease in brain water content. Myelination progresses cephalad from the brain stem at 29 weeks to reach the centrum semiovale by 42 weeks. Delayed myelination, defined as the absence of myelin in the corona radiata by 37 weeks, was seen in nine infants with complicated perinatal courses. Awareness of these developmental features should help to minimize misinterpretation of normal changes in the neonatal brain and lead to earlier detection of pathologic conditions, both with MR imaging and computed tomography.

Developmental features of the neonatal brain: MR imaging. Part II. Ventricular size and extracerebral space.

Magnetic resonance (MR) imaging with a 0.6-T magnet was performed on 51 neonates, aged 29-42 weeks postconception. In 45 neonates, the ventricular/brain ratio (V/B) at the level of the frontal horns and midbody of the lateral ventricles ranged from 0.26 to 0.34. In six other infants a V/B of 0.36 or greater was associated with either cerebral atrophy or obstructive hydrocephalus. The width of the extracerebral space measured along specified points varied little in the neonatal period and ranged from 0 to 4 mm in 48 infants. Extracerebral space widths of 5-6 mm were seen in three other infants with severe asphyxia. Prominence of the subarachnoid space overlying the posterior parietal lobes is normal in neonates and should not be confused with cerebral atrophy. The authors conclude that V/B ratios of 0.26-0.34 and extracerebral space widths of 0-4 mm represent the normal range, and that neonates whose measurements exceed these values should be followed up.

Monitoring of the neonate undergoing MR imaging: technical considerations. Work in progress.

Instrument monitoring of vital signs in neonates undergoing magnetic resonance (MR) imaging can be difficult because of the unique environmental restrictions imposed by the imager. The authors present their experience with monitoring more than 50 newborn infants and discuss the interaction of monitoring devices with the MR imager. Several MR-compatible monitors allow continuous evaluation of body temperature, heart rate, blood pressure, and auscultation of heart sounds and respiration in mechanically ventilated infants. Signal-to-noise (S/N) ratio measurements taken during imaging of the head of an infant with these monitors in place did not differ appreciably from the ratio obtained during imaging without monitors. Tip angles should be optimized to account for widely varying head size among neonates, since adverse monitoring effects are significantly compounded by improper tip angle adjustment.

Serotonin-containing neurones in vertebrate retinas.

It has been established by a combination of HPLC and electrochemical detection that frog, lizard, goldfish, rabbit, and bovine retinas contain both dopamine and serotonin. Immunohistological and immunoradiographical methods show that serotonin is localised in amacrine perikarya and processes situated in the inner plexiform layers of frog, lizard, and goldfish retinas. The amount of serotonin in the mammalian retina appears to be too low for detection in neurones. The serotonin in the bovine retina is located mainly in the inner nuclear and plexiform layers, suggesting that the amine is present in the same types of cells as found for frog, lizard, and goldfish retinas. Retinas incubated in [3H]serotonin showed that radioactivity is associated with processes in the inner plexiform layer and amacrine perikarya. These results suggest that the neuronal elements that contain endogenous serotonin also have the capacity to accumulate exogenous amine and are consistent with the opinion that serotonin has a neuronal function in retinas of a variety of vertebrates.

Localization of cholecystokinin immunoreactivity in amacrine cells of the retina.

The distribution of cholecystokinin-like immunoreactivity within frog retina was studied by immunofluorescence. Positive staining for cholecystokinin was observed in the somata of some amacrine cells and their processes within the inner plexiform layer. Chromatography of frog retinal extracts on Sephadex G-50 and parallel dilution curves show that the retinal cholecystokinin-like immunoreactivity was also found to be associated with human and bovine retinas but absent from other ocular tissue.

Serotonin: A transmitter candidate in the vertebrate retina.

It has been established by a combination of high performance liquid chromatographic and immunohistochemical methods that serotonin occurs in amacrine cell bodies and terminals situated in the inner plexiform layer of the frog retina, where enzymes for the synthesis of the same amine are also present. Potassium stimulation causes a release of previously accumulated radioactive serotonin by the retina. These findings support the opinion that serotonin is a retinal transmitter.