Australian student radiographers' experiences and perspectives in general paediatric medical imaging examinations.

INTRODUCTION: Paediatric patients differ from adult patients with respect to anatomy, examination factors, behaviour, and intellectual development, requiring dedicated specialised knowledge and expertise. In the absence of a formal dedicated paediatric medical imaging subspecialty, this study undertook to understand student radiographers' experiences and perspectives on paediatric medical imaging. METHODS: The study entailed a descriptive cross-sectional survey design entailed a 51-item closed and open-ended response questionnaire using a total sampling method. Data were collected from both under- and postgraduate student radiographers who undertook clinical placement. Data interpretation and analysis involved statistical analysis of close-ended questions and thematic analysis of open-ended questions. RESULTS: The overall response rate was 70%. Most participants acknowledged the importance of dedicated paediatric content as well as the theory content covered. The shortcoming in pre-placement practical component was overcome through varied approaches like observations and attempting through supervision whilst experiencing uncertainty, anxiety and felt unfair to risk the patient. As reported in literature like their qualified counterparts expressed similar challenges in technique adaptation, styles of interactions in gaining cooperation from both the children and parents. They also felt paediatric content and the practicals should be embedded throughout the course offering to not compromise the day-to-day service delivery. CONCLUSIONS: The study findings iterate the importance paediatric imaging in the service delivery context. The importance of undertaking these examinations reliant on experiential learning is insufficient to bridge the gap of preparation prior to placement. IMPLICATIONS FOR PRACTICE: Collaborative academic and clinical radiography education will ensure that radiography students' dedicated specialised paediatric imaging knowledge and experience are enhanced.

Botulinum toxin as a therapeutic agent.

Botulinum toxin is a presynaptic neuromuscular blocking agent that, when injected intramuscularly in minute quantities, can produce selective muscle weakness. This property is employed therapeutically to provide symptomatic relief in conditions related to excessive muscle activities in strabismus, blepharospasm, hemifacial spasm, cervical dystonia, spasmodic dysphonia (adductor type), and jaw closing dystonia. It is investigational for a long list of medical conditions. It is a marketed drug in a number of countries in the world, but its use has only been approved by different regulatory agencies for use in a limited number of conditions. The long-term effects, appropriate dose for children, and in pregnancy, and maximum dose without causing toxicity remain unclear.

Cerebral glucose metabolism in Parkinson's disease with and without dementia.

Although cognitive impairment is commonly associated with Parkinson's disease, the relative importance of cortical and subcortical pathologic changes to the development of dementia is controversial. Characteristic abnormalities in cortical glucose metabolism have been reported previously in Alzheimer's disease, a disease in which cortical changes predominate. We measured cerebral glucose metabolism with positron emission tomography in 20 control subjects and in 14 patients with PD with mental status ranging from normal to severely demented to determine whether changes in cortical glucose metabolism occur in early PD and whether the degree and pattern of metabolic change relate to the severity of dementia. The patients were divided into demented and nondemented groups according to the results of neuropsychological assessment. Age-adjusted covariance analyses were performed, since the age distribution varied between groups. The nondemented patients with PD showed widespread cortical glucose hypometabolism without any selective temporoparietal defects. The pattern of glucose hypometabolism seen in the demented patients with PD resembled that described in patients with Alzheimer's disease; ie, there was a global decrease in glucose metabolism, with more severe abnormalities observed in the temporoparietal regions.

Botulinum toxin A as treatment for drooling saliva in PD.

The authors evaluated intraparotid injections of botulinum toxin A in reducing salivary secretions and drooling in nine patients with PD. There was a marked objective reduction in secretion, and two thirds of the patients had subjective improvement in drooling. No side effects were observed. The authors conclude that botulinum toxin A promises to be a simple and effective treatment for the common problem of drooling saliva in chronic neurologic disease.

Botulinum toxin in the treatment of writer's cramp: a double-blind study.

We treated 20 patients with writer's cramp in a double-blind, placebo-controlled study. Each patient received two treatments in tandem, one with botulinum-A toxin (BTX-A) injections and another with normal saline, separated by 3 months. Treatment order was randomized and unknown to the patient and physician. Patients were assessed before each treatment and 2 and 6 weeks after each treatment by objective measurements of pen control. Twelve patients had improvement in pen control after treatment with BTX-A, but only four had significant improvement in writing. BTX-A injections are effective in relieving symptoms in selected cases of writer's cramp, particularly in those with significant wrist-joint deviation.

A double-blind, placebo-controlled, dose-ranging study to investigate the safety and efficacy of CY 208-243 in patients with Parkinson's disease.

We carried out a double-blind rising dose study of a D-1 dopamine agonist, CY 208-243, in 6 parkinsonian patients. Deficits monitored by Columbia scores were significantly improved at single doses ranging from 5 to 40 mg, though efficacy was low. Used alone, CY 208-243 was not a satisfactory therapeutic agent, and toxicity data precluded further increases in dosage.

Decreased efficacy of levodopa with carbidopa in parkinsonian patients after adrenal-to-caudate implants.

We studied 6 parkinsonian patients 6 weeks after unilateral adrenal-to-caudate implants. We withheld medications the night before each of 2 study days and gave the patients a single test dose of either a combination of levodopa and carbidopa, or levodopa alone in double-blind random order. We administered the modified Columbia scale, objective measurements of rigidity and movement velocity, and the pegboard test at regular intervals after the single test dose. The results revealed that the improvements in performance recorded by the Columbia scale and the pegboard test were significantly less on the side contralateral to the operation when patients received carbidopa, whereas there was no significant difference in performance between the 2 observations on the ipsilateral side. Carbidopa apparently crossed the disrupted blood-brain barrier and lowered the efficacy of levodopa.

The effect of dietary protein on the efficacy of L-dopa: a double-blind study.

We randomly placed 10 parkinsonian patients on high- and low-protein diets that tasted and looked alike, each for 1 week. All patients were taking L-dopa and carbidopa with or without other antiparkinson medications; medications remained unchanged. A "blind" physician recorded the modified Columbia scores, objective measurements of rigidity, movement velocity, and pegboard tests three times a day for 5 days during each week. The patients recorded fluctuations hour to hour. We measured serial blood L-dopa levels on day 4 of each week. Performance was significantly better while the patients were on low-protein diets. These results did not correlate with blood L-dopa levels, which had higher peaks in three patients while they were on high-protein diets despite inferior performance and increased number of "off" hours. Thus, high dietary protein probably affects the efficacy of L-dopa at a central level.

Angiotensin regulates endothelin-B receptor in rat inner medullary collecting duct.

Our recent studies showed that endothelin (ET)(B) receptors are downregulated in congestive heart failure. These changes in ET(B) receptor density can be prevented by angiotensin-converting enzyme inhibitors, suggesting a possible role for angiotensin. Using isolated inner medullary collecting ducts (IMCD), we examined the possibility that angiotensin-induced downregulation of ET(B) receptors is accompanied by a decrease in ET(B) receptor mRNA. Binding studies showed that overnight incubation with angiotensin II induced a downregulatiion of ET(A) and ET(B) receptors' density in IMCD by 39% and 29%, respectively. This downregulation in ET receptor density was abolished when IMCD was coincubated with angiotensin II and its receptor antagonist saralasin. Furthermore, when the cells were exposed to phorbol myristate acetate (PMA), it resulted in a reduction in ET(A) and ET(B) receptor binding sites by 41% and 34%, respectively, suggesting the involvement of protein kinase C (PKC). In isolated IMCD, ET-1 induced an increase in cyclic guanosine monophosphate (cGMP) accumulation (705 + 63 to 1,015 + 88 fmol/microg protein/5min, P <.01), and the ET-1-induced accumulation was attenuated in the presence of angiotensin II (641 + 45 to 809 + 46 fmol/microg protein/5min, P <.01). Using competitive polymerase chain reaction (PCR) method, we also observed downregulation of ET(A) and ET(B) receptors mRNA in IMCD treated with angiotensin II (ET(A), 1.09+0.11 v 0.77 + 0.07 amol/microg of total RNA, P <.01; ET(B), 14.80 + 1.95 v 8.65 + 0.67 amol/microg of total RNA, P <.01). The addition of a PKC inhibitor abolished the downregulation of ET(A) and ET(B) receptor mRNA induced by angiotensin II (ET(A), 1.25 + 0.07 v 1.19 + 0.06 amol/microg of total RNA, not significant [NS]; ET(B), 14.36 + 0.83 to 13.68 + 0.64 amol/microg of total RNA, NS). These results suggest that angiotensin II-induced downregulation of ET(A) and ET(B) receptors mRNA is mediated by a mechanism involving PKC.

Unilateral pallidotomy for reduction of parkinsonian pain.

OBJECT: The goal of this study was to determine whether unilateral pallidotomy reduces parkinsonian pain. METHODS: Twenty-one patients suffering from Parkinson's disease (PD) were followed prospectively for 1 year after they had undergone a unilateral pallidotomy to assess the procedure's effect on pain related to PD. Pain unrelated to PD was not studied. Patients scored the level of their PD pain on an ordinal scale (0-10 points) preoperatively and 6 weeks and 1 year postoperatively. The results were analyzed using Wilcoxon's paired-ranks test (with Bonferroni correction) and showed a significant reduction in overall pain scores at 6 weeks (p < 0.001) and 1 year (p = 0.001) following pallidotomy. Various types of PD pain are described and their possible pathophysiological mechanisms are presented. CONCLUSIONS: Unilateral pallidotomy significantly reduces pain attributable to Parkinson's disease.

Idiopathic cervical dystonia: Report of discordance in a pair of monozygotic twins.

The gene for idiopathic torsion dystonia (ITD) has been located on chromosome 9q32-34. It remains controversial whether cervical dystonia (CD) is genetically determined or not. A previous report of a concordant expression of CD in a pair of monozygotic twins suggested a genetic role. We report discordance in a pair of monozygotic twins, one presenting with adult-onset idiopathic CD with duration of disease for 7 yr, while the other co-twin remained normal. Family history was negative for dystonia. The pair of twins spent all their life in the same environment. This argues against the role of genetics in the etiology of CD.

The long-term response to levodopa in dopa-responsive dystonia.

We report the long-term response to levodopa in 20 patients with dopa-responsive dystonia (DRD). We found an inverse correlation between the daily dose of levodopa and duration of treatment (r=-0.59, P<0.01). Mild dyskinesias were present in 20% of our patients. Dyskinetic patients were on a higher dose of levodopa than non-dyskinetics. Dyskinesias responded to a reduction in levodopa, with no deterioration in motor function. We propose that the dopamine turnover might decrease with time, which would lead to a decrease in the requirement for levodopa and the occurrence of dyskinesias late in the course of DRD.

Occupational and environmental risk factors for Parkinson's disease.

The etiology of Parkinson's disease (PD) remains obscure. Current research suggests that a variety of occupational and environmental risk factors may be linked to PD. This paper provides an overview of major occupational and environmental factors that have been associated with the development of PD and tries to assess current thinking about these factors and their possible mechanisms of operation. While clear links to rural living, dietary factors, exposure to metals, head injury, and exposure to infectious diseases during childhood have not been established, there is general agreement that smoking and exposure to pesticides affect the probability of developing PD.

The prevalence of Parkinson's disease in British Columbia, Canada, estimated by using drug tracer methodology.

OBJECTIVE: To estimate the prevalence of Parkinson's disease (PD) in British Columbia utilizing the prescription database of the College of Pharmacists. METHODS: Patients receiving anti-parkinsonian drug (anti-PD) prescriptions between 1996 and 1998 were stratified by year, age, gender, drug use category, and geographic location. The numbers of patients on levodopa alone, or levodopa and/or other anti-PD drugs were adjusted using published data which gave estimates of the proportion of undiagnosed patients with PD, the proportion of those treated for parkinsonism with definite PD, the proportion of patients with PD not being treated with anti-PD medications, and the proportion of patients treated with anti-PD medications who have PD. Use of the anti-PD drug bromocriptine for other purposes in women under 50 years of age was also considered. RESULTS: The estimated prevalences of PD based on all anti-PD medications used were 109, 121, and 125 per 100,000 population in 1996, 1997, and 1998, respectively. Estimated prevalences of PD based on levodopa use were 126, 134, and 144, respectively. The prevalence in both prescription groups increased with age. The male to female ratio of prevalence ranged from 1.16 to 1.21. CONCLUSIONS: Using a large, accurate database, it is possible to estimate the prevalence of PD in a large population, though the assumptions built into the estimate remain to be validated in the subject population.

Future treatment of Parkinson's disease.

New methods of drug delivery and slowing down the progression of Parkinson's disease (PD) are the major goals of research. More steady drug levels in the blood are possible by means of controlled-release preparations of levodopa and long-acting dopamine agonists, as well as transcutaneous duodenal tubes and pumps for controlled subcutaneous infusion. Patches containing dopamine agonists absorbed through the skin may be developed. The role of D1 agonists as compared with D2 agonists remains to be elucidated. Agonists on autoreceptors of dopaminergic neurons may potentially reduce excessive stimulation of the intact neurons and this may slow down the rate of neuronal death in PD. Monoamine oxidase-B inhibitors may have a potentially protective action on neurons. Investigations are being carried out to evaluate this claim. Catechol-o-methyl-transferase inhibitors may be helpful in theory. There is also recent interest in inhibitors of excitatory amino acids, which may contribute to neuronal loss in PD.

Local treatment of spasmodic torticollis with botulinum toxin.

Fifty-six patients with spasmodic torticollis were treated with local injections of botulinum toxin. The drop out rate was 21%. The remaining 44 patients were followed for a period of 3 to 21 months. Thirty-two patients (76%) had pain relief out of 42 presenting with pain; 37 (66%) improved in the amount of sustained movements of torticollis. The efficacy was reproducible after repeated injections.

Optimal indices for testing parkinsonian rigidity.

We assessed parkinsonian rigidity objectively at the wrist to determine the optimal angular velocity and displacement for detecting abnormality. The wrist was moved passively with a torque motor and the average work done for one complete cycle was computed. This objective rigidity score (ORS) was compared with a clinical rigidity score (CRS). ORS was more pronounced at faster movement velocities in parkinsonian patients, whereas in normal subjects there was only a modest increase in the score. Angular velocities of 140 to 190 degrees/second and displacements of +/- 25 to +/- 30 degrees were most sensitive for detecting parkinsonian rigidity and had good correlation with the CRS.

A pilot study on the use of botulinum toxin in spasmodic torticollis.

Dystonic torticollis has been treated with local injections of botulinum toxin in a single blind study of 12 patients. A significant decrease of abnormal movements was recorded, and pain improved. Further studies are desirable to define the optimum dosage and site for injections, and the long term effects of repeated injections.

Head tremor in cervical dystonia.

OBJECTIVE: To compare the clinical characteristics, natural history, and therapeutic outcome of patients with cervical dystonia (CD) with head tremor (HT+) and without head tremor (HT-). METHODS: We prospectively evaluated 114 consecutive patients of CD over a 9-month period with a detailed questionnaire. Chi-square and t-tests were employed for statistical analysis. RESULTS: Seventy-eight (68.4%) patients had head tremor and 27 of them (34.6%) had tremor as one of the first symptoms. Age at onset of symptoms were similar in HT+ and HT- groups; however there was a higher prevalence in women in the former group (66.7% vs. 41.7%; p=0.01). HT+ patients had more frequent positive family history of essential-like hand/head tremor (21.8% vs. 5.5%; p<0.05), associated neck pain (92.3% vs. 77.8%: p<0.05), and essential-like hand tremor (40% vs. 8.3%; p<0.001). They also appeared to have more frequent history of preceding head/neck trauma (14.1% vs. 8.3%), frequent head rotation (88.5% vs. 69.4%) and antecollis (12.8% vs. 5.5%) but less often head tilt (37.2% vs. 47.2%) and gestes antagonistes (60.2% vs. 75%) than the HT- patients; however these differences were not statistically significant. The frequency of prior psychiatric illnesses, the incidence of dystonias in other parts of the body, frequency of retrocollis and shoulder elevation, and spontaneous remission were similar in the two groups. CONCLUSION: Head tremor is common in CD and is more commonly associated with hand tremor and family history of tremor or other movement disorders. This supports a possible genetic association between CD and essential tremor (ET). Linkage studies are required to evaluate the genetic association between CD and ET.

Post-traumatic cervical dystonia: a distinct entity?

BACKGROUND/OBJECTIVE: The incidence of head/neck trauma preceding cervical dystonia (CD) has been reported to be 5-21%. There are few reports comparing the clinical characteristics of patients with and without a history of injury. Our aim was to compare the clinical characteristics of idiopathic CD (CD-I) to those with onset precipitated by trauma (CD-T). METHODS: We evaluated 114 consecutive patients with CD over a 9-month period. All patients were interviewed using a detailed questionnaire and had a neurological examination. Their clinical charts were also reviewed. RESULTS: Fourteen patients (12%) had mild head/neck injury within a year preceding the onset of CD. Between the two groups (CD-I and CD-T), the gender distribution (F:M of 3:2), family history of movement disorders (32% vs. 29%), the prevalence of gestes antagonistes (65% vs. 64%), and response to botulinum toxin were similar. There were non-specific trends, including an earlier age of onset (mean ages 43.3 vs. 37.6), higher prevalence of neck pain (86% vs. 100%), head tremor (67% vs. 79%), and dystonia in other body parts (23% vs. 36%) in CD-T. CONCLUSIONS: CD-I and CD-T are clinically similar. Trauma may be a triggering factor in CD but this was only supported by non-significant trends in its earlier age of onset.