Pandemic Responsiveness in an Acute Care Setting: A Community Hospital's Utilization of Operational Resources During COVID-19

Background

To ensure continuity of services while mitigating patient surge and nosocomial infections during the coronavirus disease 2019 (COVID-19) pandemic, acute care hospitals have been required to make significant operational adjustments. Here, we identify and discuss key administrative priorities and strategies utilized by a large community hospital located in Ontario, Canada.

Methods

Guided by a qualitative descriptive approach, we performed a thematic analysis of all COVID-19-related documentation discussed by the hospital’s emergency operation centre (EOC) during the pandemic’s first wave. We then solicited operational strategies from a multidisciplinary group of hospital leaders to construct a narrative for each theme.

Results

Seven recurrent themes critical to the hospital’s pandemic response emerged: 1) Organizational structure: a modified EOC structure was adopted to increase departmental interoperability and situational awareness; 2) Capacity planning: Design Thinking guided rapid infrastructure decisions to meet surge requirements; 3) Occupational health and workplace safety: a multidisciplinary team provided respirator fit-testing, critical absence adjudication, and wellness needs; 4) Human resources/workforce planning: new workforce planning, recruitment, and redeployment strategies addressed staffing shortages; 5) Personal protective equipment (PPE): PPE conservation required proactive sourcing from traditional and non-traditional suppliers; 6) Community response: local partnerships were activated to divert patients through a non-referral-based assessment and treatment centre, support long-term care and retirement homes, and establish a 70-bed field hospital; and 7) Corporate communication: a robust communication strategy provided timely and transparent access to rapidly evolving information.

Conclusion

A community hospital’s operational preparedness for COVID-19 was supported by inter-operability, leveraging internal and external expertise and partnerships, creative problem solving, and developing novel tools to support occupational health and community initiatives.

Analysing how changes in the health status of healthcare workers affects epidemic outcomes

During a disease outbreak, healthcare workers (HCWs) are essential to treat infected individuals. However, these HCWs are themselves susceptible to contracting the disease. As more HCWs get infected, fewer are available to provide care for others, and the overall quality of care available to infected individuals declines. This depletion of HCWs may contribute to the epidemic's severity. To examine this issue, we explicitly model declining quality of care in four differential equation-based susceptible, infected and recovered-type models with vaccination. We assume that vaccination, recovery and survival rates are affected by quality of care delivered. We show that explicitly modelling HCWs and accounting for declining quality of care significantly alters model-predicted disease outcomes, specifically case counts and mortality. Models neglecting the decline of quality of care resulting from infection of HCWs may significantly under-estimate cases and mortality. These models may be useful to inform health policy that may differ for HCWs and the general population. Models accounting for declining quality of care may therefore improve the management interventions considered to mitigate the effects of a future outbreak.

The Strategy of Predator Evasion in Response to a Visual Looming Stimulus in Zebrafish (Danio rerio)

A diversity of animals survive encounters with predators by escaping from a looming visual stimulus. Despite the importance of this behavior, it is generally unclear how visual cues facilitate a prey’s survival from predation. Therefore, the aim of this study was to understand how the visual angle subtended on the eye of the prey by the predator affects the distance of adult zebrafish (Danio rerio) from predators. We performed experiments to measure the threshold visual angle and mathematically modeled the kinematics of predator and prey. We analyzed the responses to the artificial stimulus with a novel approach that calculated relationships between hypothetical values for a threshold-stimulus angle and the latency between stimulus and response. These relationships were verified against the kinematic responses of zebrafish to a live fish predator (Herichthys cyanoguttatus). The predictions of our model suggest that the measured threshold visual angle facilitates escape when the predator’s approach is slower than approximately twice the prey’s escape speed. These results demonstrate the capacity and limits to how the visual angle provides a prey with the means to escape a predator.

Screening for Vitamin D Deficiency in Black Americans: Comparison of Total, Free, Bioavailable 25 Hydroxy Vitamin D Levels with Parathyroid Hormone Levels and Bone Mineral Density

OBJECTIVES

There is debate surrounding the adequacy of total and free 25 hydroxy vitamin D [25(OH)D] levels in black Americans who have inherently high bone mineral density [BMD] and low serum concentration of vitamin D binding proteins [VDBP].

DESIGN

Retrospective analysis of serum samples and BMD analyses from the African American Health Study [AAHS] cohort.

SETTING

The AAHS is a population-based longitudinal study initiated to examine issues of disability and frailty among urban-dwelling black Americans in the city of Saint Louis, Missouri.

PARTICIPANTS

122 men and 206 women, age 60.2 ± 4.3 years.

INTERVENTION

Retrospective analysis.

MEASUREMENTS

Total 25(OH)D, VDBP, PTH, and BMD of the lumbar spine and hip by dual energy x-ray photometry (DXA). Free and bioavailable vitamin D levels were calculated using serum concentrations and affinity constants for the VDBP (Gc1F and Gc1S) phenotypes.

RESULTS

Serum total 25(OH)D levels were 14.6 ± 8.9 ng/mL (36 ± 22 nmol/L). Vitamin D insufficiency was estimated by compensatory elevations of PTH above the normal range (> 65 pg/mL). PTH levels were within the normal reference range in > 95% of the samples at total 25(OH)D levels ≥ 20 ng/mL (≥50 nmol/L). There was no difference in the correlation of the reciprocal relationship of vitamin D vs parathyroid hormone between the VDBP phenotypes. Receiver operating characteristic curve analyses indicated that serum total 25(OH)D discriminated sufficiency from insufficiency at least as well as the calculated levels of the free and bioavailable vitamin D. Very low levels of total 25(OH)D (≤ 8 ng/mL, ≤20 nmol/L) were associated with decreased BMD (p=0.02), but higher levels of 25(OH)D did not show statistical differences in BMD.

CONCLUSION

Total 25(OH)D levels of ≤ 8ng/mL (≤20 nmol/L) are associated with clinically significant changes in BMD, whereas total 25(OH)D levels ≥ 20 ng/mL (≥50 nmol/L) suppressed PTH and were not associated with deficiencies in BMD. Lower levels of 25(OH)D may be acceptable for bone health in black than in white Americans.

High-resolution magnetic resonance imaging reveals nuclei of the human amygdala: manual segmentation to automatic atlas

The amygdala is composed of multiple nuclei with unique functions and connections in the limbic system and to the rest of the brain. However, standard in vivo neuroimaging tools to automatically delineate the amygdala into its multiple nuclei are still rare. By scanning postmortem specimens at high resolution (100-150µm) at 7T field strength (n = 10), we were able to visualize and label nine amygdala nuclei (anterior amygdaloid, cortico-amygdaloid transition area; basal, lateral, accessory basal, central, cortical medial, paralaminar nuclei). We created an atlas from these labels using a recently developed atlas building algorithm based on Bayesian inference. This atlas, which will be released as part of FreeSurfer, can be used to automatically segment nine amygdala nuclei from a standard resolution structural MR image. We applied this atlas to two publicly available datasets (ADNI and ABIDE) with standard resolution T1 data, used individual volumetric data of the amygdala nuclei as the measure and found that our atlas i) discriminates between Alzheimer's disease participants and age-matched control participants with 84% accuracy (AUC=0.915), and ii) discriminates between individuals with autism and age-, sex- and IQ-matched neurotypically developed control participants with 59.5% accuracy (AUC=0.59). For both datasets, the new ex vivo atlas significantly outperformed (all p < .05) estimations of the whole amygdala derived from the segmentation in FreeSurfer 5.1 (ADNI: 75%, ABIDE: 54% accuracy), as well as classification based on whole amygdala volume (using the sum of all amygdala nuclei volumes; ADNI: 81%, ABIDE: 55% accuracy). This new atlas and the segmentation tools that utilize it will provide neuroimaging researchers with the ability to explore the function and connectivity of the human amygdala nuclei with unprecedented detail in healthy adults as well as those with neurodevelopmental and neurodegenerative disorders.

The effects of maternal immunity and age structure on population immunity to measles

Measles was successfully eradicated in the Pan-American Health Region in 2002. However, maintenance of elimination in parts of Africa, Europe, the USA, and other regions is proving difficult, despite apparently high vaccine coverage. This may be due to the different age structure in developed and developing populations, as well as to differences in the duration of maternal immunity. We explore the interaction between maternal immunity and age structure and quantify the resulting immunity gap between vaccine coverage and population immunity; we use this immunity gap as a novel metric of vaccine program success as it highlights the difference between actual and estimated immunity. We find that, for some combinations of maternal immunity and age structure, the accepted herd immunity threshold is not maintainable with a single-dose vaccine strategy for any combination of target age and coverage. In all cases, the herd immunity threshold is more difficult to maintain in a population with developing age structure. True population immunity is always improved if the target age at vaccination is chosen for the specific combination of maternal immunity and age structure.

Fitness to fly testing in term and ex-preterm babies without bronchopulmonary dysplasia

BACKGROUND

During air flight, cabin pressurisation produces an effective fraction of inspired oxygen (FiO(2)) of 0.15. This can cause hypoxia in predisposed individuals, including infants with bronchopulmonary dysplasia (BPD), but the effect on ex-preterm babies without BPD was uncertain. The consequences of feeding a baby during the hypoxia challenge were also unknown.

METHODS

Ex-preterm (without BPD) and term infants had fitness to fly tests (including a period of feeding) at 3 or 6 months corrected gestational age (CGA) in a body plethysmograph with an FiO(2) of 0.15 for 20 min. A 'failed' test was defined as oxygen saturation (SpO(2)) <90% for at least 2 min.

RESULTS

41 term and 30 ex-preterm babies (mean gestational age 39.8 and 33.1 weeks, respectively) exhibited a significant median drop in SpO(2) (median -6%, p<0.0001); there was no difference between term versus ex-preterm babies, or 3 versus 6 months. Two term (5%) and two ex-preterm (7%) babies failed the challenge. The SpO(2) dropped further during feeding (median -4% in term and -2% in ex-preterm, p<0.0001), with transient desaturation (up to 30 s) <90% seen in 8/36 (22%) term and 9/28 (32%) ex-preterm infants; the ex-preterm babies desaturated more quickly (median 1 vs 3 min, p=0.002).

CONCLUSIONS

Ex-preterm babies without BPD and who are at least 3 months CGA do not appear to be a particularly at-risk group for air travel, and routine preflight testing is not indicated. Feeding babies in an FiO(2) of 0.15 leads to a further fall in SpO(2), which is significant but transient.

Closed suction surgical wound drainage after anterior cruciate ligament reconstruction: a systematic review of randomised controlled trials

There is still debate over the use of drains following anterior cruciate ligament reconstruction surgery. We have performed a systematic review of the literature for randomised trials that related to the use of closed suction drains following anterior cruciate ligament reconstruction surgery. Five studies involving 349 patients were identified. There was no significant difference in the occurrence of wound healing complications, infections or the number of aspirations for haemarthrosis. There was also no difference in post-operative range of movement, functional score or incidence of limb swelling. The difference in pain scores varied between authors with some reporting increased pain in the drained group. All other outcomes reported failed to show any benefit for the use of drains. The authors recommend not using a drain following anterior cruciate ligament reconstruction with either Bone-Patellar Tendon-Bone or Quadrupled Hamstring graft.

Closed suction surgical wound drainage after hip fracture surgery: a systematic review and meta-analysis of randomised controlled trials

There is still debate over the use of drains following hip fracture surgery. We have performed a systematic review and meta-analysis of the literature for randomised trials that related to the use of closed suction drains following hip fracture surgery. Six studies involving 664 patients were identified. There was no statistically significant difference in the occurrence of wound healing complications, re-operations or requirement for blood transfusion between drained and un-drained wounds. All other outcomes reported failed to show any benefit from the use of drains. Further randomised trials are required and until they have been undertaken the efficacy of closed surgical drainage systems in hip fracture surgery is unknown.

Closed suction surgical wound drainage after orthopaedic surgery

BACKGROUND

Closed suction drainage systems are frequently used to drain fluids, particularly blood, from surgical wounds. The aim of these systems is to reduce the occurrence of wound haematomas and infection.

OBJECTIVES

To evaluate the effectiveness of closed suction drainage systems for orthopaedic surgery.

SEARCH STRATEGY

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (March 2006), and contacted the Cochrane Wounds Group. We also searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2006, Issue 1), and MEDLINE (1966 to March 2006). Articles of all languages were considered.

SELECTION CRITERIA

All randomised or quasi-randomised trials comparing the use of closed suction drainage systems with no drainage systems for all types of elective and emergency orthopaedic surgery.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality, using a nine item scale, and extracted data. Where appropriate, results of comparable studies were pooled.

MAIN RESULTS

Thirty-six studies involving 5464 participants with 5697 surgical wounds were identified. The types of surgery involved were hip and knee replacement, shoulder surgery, hip fracture surgery, spinal surgery, cruciate ligament reconstruction, open meniscectomy and fracture fixation surgery. Pooling of results indicated no statistically significant difference in the incidence of wound infection, haematoma, dehiscence or re-operations between those allocated to drains and the un-drained wounds. Blood transfusion was required more frequently in those who received drains. The need for reinforcement of wound dressings and the occurrence of bruising were more common in the group without drains.

AUTHORS' CONCLUSIONS

There is insufficient evidence from randomised trials to support the routine use of closed suction drainage in orthopaedic surgery. Further randomised trials with larger patient numbers are required for different operations before definite conclusions can be made for all types of orthopaedic operations.

Re-assessing the relationship between cholesterol, statins and Alzheimer's disease

This communication integrates the purported role of cholesterol and statins in Alzheimer's disease (AD) with recent data. Meta-analysis of association studies relevant to AD indicates that apolipoprotein (apo)E4 is the only cholesterol-related polymorphism that shows clear association with AD. This suggests that the effect of apoE4 on the pathophysiology of AD occurs via a mechanism that is not directly related to cholesterol, such as fibrillization of Abeta. Despite the lack of genetic association, cholesterol and statins clearly modulate amyloid precursor protein (APP) processing in cell culture and animal models. Statins appear to act by a pleiotropic mechanism, involving both cholesterol (via lipid rafts) and isoprenylation. The pleiotropic mechanism of statin action clarifies conflicting data from clinical studies, where statins exert an action on Abeta and AD that might be dose dependent because of actions on both cholesterol and isoprenylation. Reduced isoprenylation can also inhibit inflammation. Our own studies of brains from Alzheimer subjects +/- statins indicate that statins inhibit inflammation in humans but might not reduce cerebral Abeta load. These results suggest that the primary action of statins in humans with AD might be to reduce inflammation rather than decrease Abeta load.

Dementia

Alzheimer's disease is the most common cause of dementia, but often several other conditions causing dementia are present on brain autopsies. Palliative care medical issues are similar in all late stage progressive degenerative dementias and include; cardiopulmonary resuscitation, transfer to acute care setting, antibiotic therapy, and tube feeding. Behavioral symptoms of dementia include agitation and resistiveness to care. Quality of life of individuals suffering from dementia is enhanced by availability of meaningful activities and by avoidance of restraints. Family support and involvement are crucial for optimal care. Formulation of advanced directives or an advance proxy plan is important for assuring the patient's previous wishes or best interests are considered when decisions about treatment strategies are made.

Functional cloning of the proto-oncogene brain factor-1 (BF-1) as a Smad-binding antagonist of transforming growth factor-beta signaling

Using the plasminogen activator inhibitor (PAI) promoter to drive the expression of a reporter gene (mouse CD2), we devised a system to clone negative regulators of the transforming growth factor-beta (TGF-beta) signaling pathway. We infected a TGF-beta-responsive cell line (MvLu1) with a retroviral cDNA library, selecting by fluorescence-activated cell sorter single cells displaying low PAI promoter activity in response to TGF-beta. Using this strategy we cloned the proto-oncogene brain factor-1 (BF-1). BF-1 represses the PAI promoter in part by associating with both unphosphorylated Smad3 (in the cytoplasm) and phosphorylated Smad3 (in the nucleus), thus preventing its binding to DNA. BF-1 also associates with Smad1, -2, and -4; the Smad MH2 domain binds to BF-1, and the C-terminal segment of BF-1 is uniquely and solely required for binding to Smads. Further, BF-1 represses another TGF-beta-induced promoter (p15), it up-regulates a TGF-beta-repressed promoter (Cyclin A), and it reverses the growth arrest caused by TGF-beta. Our results suggest that BF-1 is a general inhibitor of TGF-beta signaling and as such may play a key role during brain development.

Progression of dysarthria and dysphagia in postmortem-confirmed parkinsonian disorders

BACKGROUND

Dysarthria and dysphagia are known to occur in parkinsonian syndromes such as Parkinson disease (PD), dementia with Lewy bodies (DLB), corticobasal degeneration (CBD), multiple system atrophy (MSA), and progressive supranuclear palsy (PSP). Differences in the evolution of these symptoms have not been studied systematically in postmortem-confirmed cases.

OBJECTIVE

To study differences in the evolution of dysarthria and dysphagia in postmortem-confirmed parkinsonian disorders.

PATIENTS AND METHODS

Eighty-three pathologically confirmed cases (PD, n = 17; MSA, n = 15; DLB, n = 14; PSP, n = 24; and CBD, n = 13) formed the basis for a multicenter clinicopathological study organized by the National Institute of Neurological Disorders and Stroke, Bethesda, Md. Cases with enough clinicopathological documentation for the purpose of the study were selected from research and neuropathological files of 7 medical centers in 4 countries (Austria, France, England, and the United States).

RESULTS

Median dysarthria latencies were short in PSP and MSA (24 months each), intermediate in CBD and DLB (40 and 42 months), and long in PD (84 months). Median dysphagia latencies were intermediate in PSP (42 months), DLB (43 months), CBD (64 months), and MSA (67 months), and long in PD (130 months). Dysarthria or dysphagia within 1 year of disease onset was a distinguishing feature for atypical parkinsonian disorders (APDs) (specificity, 100%) but failed to further distinguish among the APDs. Survival time after onset of a complaint of dysphagia was similar in PD, MSA, and PSP (15 to 24 months, P =.7) and latency to a complaint of dysphagia was highly correlated with total survival time (rho = 0.88; P<.001) in all disorders.

CONCLUSIONS

Latency to onset of dysarthria and dysphagia clearly differentiated PD from the APDs, but did not help distinguish different APDs. Survival after onset of dysphagia was similarly poor among all parkinsonian disorders. Evaluation and adequate treatment of patients with PD who complain of dysphagia might prevent or delay complications such as aspiration pneumonia, which in turn may improve quality of life and increase survival time.

Reduction of postoperative mortality and morbidity with epidural or spinal anaesthesia: results from overview of randomised trials

OBJECTIVES

To obtain reliable estimates of the effects of neuraxial blockade with epidural or spinal anaesthesia on postoperative morbidity and mortality.

DESIGN

Systematic review of all trials with randomisation to intraoperative neuraxial blockade or not.

STUDIES

141 trials including 9559 patients for which data were available before 1 January 1997. Trials were eligible irrespective of their primary aims, concomitant use of general anaesthesia, publication status, or language. Trials were identified by extensive search methods, and substantial amounts of data were obtained or confirmed by correspondence with trialists.

MAIN OUTCOME MEASURES

All cause mortality, deep vein thrombosis, pulmonary embolism, myocardial infarction, transfusion requirements, pneumonia, other infections, respiratory depression, and renal failure.

RESULTS

Overall mortality was reduced by about a third in patients allocated to neuraxial blockade (103 deaths/4871 patients versus 144/4688 patients, odds ratio=0.70, 95% confidence interval 0.54 to 0.90, P=0. 006). Neuraxial blockade reduced the odds of deep vein thrombosis by 44%, pulmonary embolism by 55%, transfusion requirements by 50%, pneumonia by 39%, and respiratory depression by 59% (all P<0.001). There were also reductions in myocardial infarction and renal failure. Although there was limited power to assess subgroup effects, the proportional reductions in mortality did not clearly differ by surgical group, type of blockade (epidural or spinal), or in those trials in which neuraxial blockade was combined with general anaesthesia compared with trials in which neuraxial blockade was used alone.

CONCLUSIONS

Neuraxial blockade reduces postoperative mortality and other serious complications. The size of some of these benefits remains uncertain, and further research is required to determine whether these effects are due solely to benefits of neuraxial blockade or partly to avoidance of general anaesthesia. Nevertheless, these findings support more widespread use of neuraxial blockade.

Progression of Hoehn and Yahr stages in Parkinsonian disorders: a clinicopathologic study

The progression to different Hoehn and Yahr (HY) stages was evaluated in 81 pathologically confirmed patients with parkinsonism. Patients with PD (n = 18) showed significantly longer latencies to each HY stage than patients with atypical parkinsonian disorder (APD). While no patient with PD developed a HY-III stage within 1 year of onset of motor symptoms, 72% of those with APDs did. In fact, development of a HY-III within 1 year of motor onset accurately predicted an APD. However, the progression to each HY stage was unhelpful in distinguishing the APDs from each other. Once patients with PD and APD became wheelchair-bound, both had equally short survival times.

Serum amyloid A in Alzheimer's disease brain is predominantly localized to myelin sheaths and axonal membrane

Immunohistochemical localization of the injury specific apolipoprotein, acute phase serum amyloid A (A-apoSAA), was compared in brains of patients with neuropathologically confirmed Alzheimer's disease (AD), multiple sclerosis (MS), Parkinson's disease (PD); Pick's disease (Pick's), dementia with Lewy bodies (DLB), coronary artery disease (CAD), and schizophrenia. Affected regions of both AD and MS brains showed intense staining for A-apoSAA in comparison to an unaffected region and non-AD/MS brains. The major site of A-apoSAA staining in both diseases was the myelin sheaths of axons in layers V and VI of affected cortex. A-apoSAA contains a cholesterol binding site near its amino terminus and is likely to have a high affinity for cholesterol-rich myelin. These findings, along with our recent evidence that A-apoSAA can inhibit lipid synthesis in vascular smooth muscle cells suggest that A-apoSAA plays a role in the neuronal loss and white matter damage occurring in AD and MS.

Cross-talk between phosphatidylinositol 3-kinase and sphingomyelinase pathways as a mechanism for cell survival/death decisions

Peptide hormones act to regulate apoptosis through activation of multiple pro- and anti-apoptotic signaling cascades of which lipid signaling events represent an important facet of the cellular rheostat that determines survival and death decisions. Activation of sphingomyelinase, which generates ceramide, is an intermediate in cellular stress responses and induction of apoptosis in many systems. Conversely, phosphatidylinositol 3-kinase (PI3K) is a critical signaling molecule involved in regulating cell survival and proliferation pathways. In the present study, we investigate cross-talk between the PI3K and sphingomyelinase pathways as a mechanism for regulation of cell survival/death decisions. We show that phorbol ester, insulin-like growth factor 1, and a constitutively active PI3K suppress both tumor necrosis factor-induced apoptosis and ceramide generation. Conversely, inhibition of the PI3K pathway with expression of a kinase-dead PI3K both prevented survival signaling and enhanced tumor necrosis factor-induced ceramide generation. The ability of exogenous sphingomyelinase to induce ceramide generation was partially suppressed by expression of constitutively active PI3K and enhanced by inhibition of PI3K suggesting that cross-talk between PI3K and ceramide generation within cells is regulated subsequent to activation of sphingomyelinase.

Possible role of the superoxide anion in the development of neuronal tolerance following ischaemic preconditioning in rats

There is a large body of evidence that reactive oxygen species play a major role in the pathogenesis of ischaemic brain damage. On the other hand, it has recently been suggested that superoxide anions participate in the development of neuronal tolerance against lethal ischaemia following ischaemic preconditioning (PC). The present study aimed to examine whether or not the intravenous administration of human recombinant Cu/Zn superoxide dismutase (hr SOD) prior to PC would affect the subsequent development of neuronal tolerance. Animals were randomly assigned to the following three groups: group 1, sham PC treated with vehicle; group 2, PC treated with hr SOD and group 3, PC treated with vehicle. For PC, 10 min occlusion of the middle cerebral artery (MCA) by a modified intraluminal suture method was followed by 60 min recirculation and this procedure was successively repeated three times. The procedures were similar for sham PC except that the MCA was kept unoccluded. Just prior to PC or sham PC, a bolus of hr SOD (6 x 103 IU/2 ml/kg) was administered intravenously. Seventy-two hours thereafter, rats were subjected to lethal ischaemia, i.e. MCA occlusion for 100 min followed by recirculation for 48 h. The infarct area and volume were assessed with the 2,3,5-triphenyltetrazolium stain. A significant difference in the infarct volume was revealed between the sham PC/vehicle and the PC/vehicle groups (total and cortex P < 0.01; striatum P < 0.05), showing that PC induced a marked neuronal tolerance against lethal ischaemia. The infarct volume in the PC/SOD group was close to that in the sham PC/vehicle group, being significantly greater than that in the PC/vehicle group (total and cortex P < 0.01) and showing that the administration of hr SOD suppressed the development of neuronal tolerance induced by PC. In a parallel experiment, expression of 72-kDa heat-shock protein (hsp 72) at 72 h after PC was considerably reduced in rats treated with hr SOD compared with those treated with vehicle. These results suggest that superoxide anions intraluminally generated within cerebral microvessels participate in the development of neuronal tolerance as well as the induction of hsp 72 following PC.

Progression of falls in postmortem-confirmed parkinsonian disorders

Although falls are known to occur in several parkinsonian disorders, such as Parkinson's disease (PD), multiple system atrophy (MSA), dementia with Lewy bodies (DLB), corticobasal degeneration (CBD), and progressive supranuclear palsy (PSP), differences in the evolution of this feature have not been studied systematically in pathologically confirmed cases. Seventy-seven cases with pathologically confirmed parkinsonian disorders (PD: n = 11, MSA: n = 15, DLB: n = 14, CBD: n = 13, PSP: n = 24), collected up to 1994, formed the basis for a multicenter clinicopathologic study organized by the National Institute of Neurological Disorders and Stroke to improve differential diagnosis of parkinsonian disorders. In the present study, we determined the time course, that is, the duration from first symptom to onset (latency) and duration from onset to death, of recurrent falls. Furthermore, we analyzed the diagnostic validity of a predefined latency to onset of recurrent falls within 1 year of symptom onset. Significant group differences for latency, but not duration, of recurrent falls were observed. Latencies to onset of falls were short in PSP patients, intermediate in MSA, DLB, and CBD, and long in PD. Recurrent falls occurring within the first year after disease onset predicted PSP in 68% of the patients. Our study demonstrates for the first time that latency to onset, but not duration, of recurrent falls differentiates PD from other parkinsonian disorders. Whereas early falls are important for the diagnosis of PSP, the addition of other features increases its diagnostic predictive value.

Clinical features differentiating patients with postmortem confirmed progressive supranuclear palsy and corticobasal degeneration

Progressive supranuclear palsy (PSP) and cortocobasal degeneration (CBD) are often clinically confused with each other because they share a rapid disease progression, parkinsonism that responds poorly or transiently to levodopa therapy, and associated signs (e.g., ocular abnormalities, pyramidal signs and cognitive involvement). To improve the accuracy in diagnosing these disorders, this study examined the clinical features of 51 patients pathologically diagnosed with PSP and CBD. Logistic regression analysis identified two sets of predictors (models) for CBD patients, one consisting of asymmetric parkinsonism, cognitive disturbances at onset and instability and falls at first clinic visit, and the other one of asymmetric parkinsonism, cognitive disturbances at symptom onset and speech disturbances. While PSP patients often had severe postural instability at onset, symmetric parkinsonism, vertical supranuclear gaze palsy, speech and frontal lobe-type features, CBD patients presented with lateralized motor (e.g., parkinsonism, dystonia or myoclonus) and cognitive signs (e.g., ideomotor apraxia, aphasia or alien limb). On the other hand, CBD patients presenting with an alternate phenotype characterized by early severe frontal dementia and bilateral parkinsonism were generally misdiagnosed. PSP patients without vertical supranuclear gaze palsy were misdiagnosed. Recognizing the features which differentiate these disorders and the less obvious disease presentations as well as developing an increased index of suspicion will improve the diagnostic accuracy of these disorders.

Wound tensile strength and contraction rate are not affected by laparotomy or pneumoperitoneum

BACKGROUND

Many cellular elements responsible for wound healing are affected by laparotomy. The aim of this study was to evaluate the effects of laparotomy and CO2 pneumoperitoneum on wound healing.

METHODS

Male Sprague Dawley rats were randomly assigned to one of three experimental groups. Anesthesia control rats underwent no procedure. Pneumoperitoneum group rats were insufflated with CO2 gas. Laparotomy group rats underwent a 7-cm midline laparotomy incision. The interventions were 30 min long. For the incisional study (n = 30), a 4-cm dorsal full-thickness skin incision was made on each rat and then closed with staples. On postoperative days 7 and 14, an equal number of rats were sacrificed from each group, and wound tensile strength measurements were performed. For the excisional study (n = 45), each group of 15 rats underwent a 2-cm diameter circular dorsal full-thickness skin excision. Blinded measurements of wound area were performed every other day until wounds closed.

RESULTS

Wound tensile strength values were not significantly different among experimental groups at either time point. The study had a power of 80% to find a 30% difference at POD 7 and a power of 80% to find a 23% difference at POD 14 to a confidence level of p < 0.05. Wound contraction data from the excisional model were analyzed with the Generalized Estimation Equations statistical approach. When we modeled the treatment group as a covariate, no statistical difference was found between groups, demonstrating equal slopes across time.

CONCLUSIONS

From the results of these studies, we conclude that wound healing in this model is not significantly diminished following laparotomy or peritoneal insufflation, as compared to anesthesia control.

Accuracy of the clinical diagnosis of postencephalitic parkinsonism: a clinicopathologic study

The accuracy of the clinical diagnosis of postencephalitic parkinsonism (PEP) is unknown. We determined the validity of the clinical diagnosis of PEP by presenting 105 records with neuropathologic diagnoses of PEP (n = 7), progressive supranuclear palsy (n = 24), Parkinson's disease (n = 15), dementia with Lewy bodies (n = 14), multiple system atrophy (n = 16), corticobasal degeneration (n = 10), Creutzfeldt-Jakob disease (n = 4), and other dementia disorders (n = 15), as clinical vignettes to six neurologists unaware of the autopsy findings. The neurologists' own clinical diagnoses were compared with neuropathologic diagnoses for measures of diagnostic accuracy, including reliability (kappa statistics), sensitivity and positive predictive values for the first and last visits. The group reliability for the diagnosis of PEP was almost perfect (kappa = 0.91, 0.9). The mean sensitivity at the first visit was 86% (range, 71-100%) with minimal change at the last visit (83%; range, 71-100%). Positive predictive values remained unchanged (100%). The high reliability, sensitivity and positive predictive values of the clinical diagnosis of PEP indicate that neurologists identify this disorder even when they report that they have never evaluated a case. In our data set, the best predictors for the diagnosis of PEP included onset below middle age; symptom duration lasting more than 10 years, and the presence of oculogyric crisis. History of encephalitis lethargica, present in most PEP cases, was an important individual diagnostic predictor. Copyright 1998 Lippincott Williams & Wilkins

Retrospective application of a set of clinical diagnostic criteria for the diagnosis of multiple system atrophy

We estimated the accuracy of a modified commonly used set of clinical diagnostic criteria for the diagnosis of multiple system atrophy (MSA) by retrospectively applying the criteria to the features recorded by six neurologists who had evaluated 105 autopsy-confirmed cases (16 MSA and 89 non-MSA disorders). Cases were abstracted from the records of the patients' first visit to an academic center, and were presented as clinical vignettes to six neurologists, each of whom recorded the main clinical features of the presented clinical vignette on a standardized form. Sensitivity and positive predictive values were chosen as validity outcome measures and were calculated by comparing the applied diagnostic criteria to the neuropathologic information. Of note, most MSA patients in this study (mainly those with Shy-Drager type) had not received levodopa therapy since the primary neurologists often had not perceived a need to administer this treatment. The validity of the retrospectively applied criteria for the diagnosis of possible MSA (sensitivity: median, 53%, range, 50-69%; positive predictive value: 30%, 28-39%) and probable MSA (sensitivity: 44%, 31-60%; positive predictive value: 68%, 54-80%) at the first visit was suboptimal. The best, still not perfect, accuracy for this set of diagnostic criteria was obtained when six out of eight features (sporadic adult onset, dysautonomia, parkinsonism, pyramidal signs, cerebellar signs, no levodopa response, no cognitive dysfunction, or no downward gaze supranuclear palsy) were present (median sensitivity, 59%; range, 50-75%; positive predictive value: 67%, 53-83%). This is the first study to validate criteria for the clinical diagnosis of MSA. Our data suggest that it is difficult to achieve an early and accurate clinical diagnosis of this disorder. The probability of correctly diagnosing MSA increases when at least six features of this modified set of criteria are present or when requiring the set for probable MSA.

Accuracy of the clinical diagnoses of Lewy body disease, Parkinson disease, and dementia with Lewy bodies: a clinicopathologic study

BACKGROUND

Whether Parkinson disease (PD) and dementia with Lewy bodies (DLB) represent 2 distinct nosologic entities or are diverse phenotypes of Lewy body disease is subject to debate.

OBJECTIVES

To determine the accuracy of the diagnoses of Lewy body disease, PD, and DLB by validating the clinical diagnoses of 6 neurologists with the neuropathologic findings and to identify early predictors of the diagnoses.

METHODS

Six raters who were unaware of the neuropathologic diagnoses analyzed 105 clinical vignettes corresponding to 29 cases of Lewy body disease (post hoc analysis of 15 patients with PD and 14 with DLB) and 76 patients without PD or DLB whose cases were confirmed through autopsy findings.

MAIN OUTCOME MEASURES

Sensitivity and positive predictive value (PPV) were chosen as validity measures and the K statistic as a reliability measure.

RESULTS

Interrater reliability for the diagnoses of Lewy body disease and PD was moderate for the first visit and substantial for the last, whereas agreement for diagnosis of DLB was fair for the first visit and slight for the last. Median sensitivity for diagnosis of Lewy body disease was 56.9% for the first visit and 67.2% for the last; median PPV was 60.0% and 77.4%, respectively. Median sensitivity for the diagnosis of PD was 73.3% for the first visit and 80.0% for the last; median PPV was 45.9% and 64.1%, respectively. Median sensitivity for the diagnosis of DLB was 17.8% for the first visit and 28.6% for the last; median PPV was 75.0% for the first visit and 55.8% for the last. The raters' results were similar to those of the primary neurologists. Several features differentiated PD from DLB, predicted each disorder, and could be used as clinical pointers.

CONCLUSIONS

The low PPV with relatively high sensitivity for the diagnosis of PD suggests overdiagnosis. Conversely, the extremely low sensitivity for the diagnosis of DLB suggests underdiagnosis. Although the case mix included in the study may not reflect the frequency of these disorders in practice, limiting the clinical applicability of the validity measures, the raters' results were similar to those of the primary neurologists who were not exposed to such limitations. Overall, our study confirms features suggested to predict these disorders, except for the early presence of postural imbalance, which is not indicative of either disorder.

The effect of duration of cerebral ischemia on brain pyruvate dehydrogenase activity, energy metabolites, and blood flow during reperfusion in gerbil brain

The objective of this study was to determine whether the duration of an ischemic insult effects the activity of the mitochondrial enzyme pyruvate dehydrogenase (PDH) in relation to the recovery of metabolites and regional cerebral blood flow (rCBF) immediately after ischemia and during reperfusion in gerbil cortex. Cerebral ischemia was induced, using the bilateral carotid artery occlusion method, for 20 or 60 min, followed by reperfusion up to 120 min. Immediately after ischemia PDH activity increased threefold regardless of ischemic duration. In the 60-min ischemic group, PDH remained activated, the recovery of high energy phosphates and the clearance of lactate were poor, and the rCBF was 48% of controls after 20-min reperfusion, decreasing gradually to 26% at 120-min reperfusion. In the 20-min ischemic group, PDH activity normalized quickly, the restoration of energy phosphates was good, there was a quick reduction in lactate within the first 60 min of reperfusion, and the rCBF was 65% of control at 20-min reperfusion, and remained over 48% of control throughout reperfusion. Recovery of metabolism after reperfusion did not parallel the changes in rCBF in either group, most noticeably in the 60-min ischemic group. The slow normalization of PDH activity reflected the poor recovery of metabolites in the 60-min ischemic group, indicating that PDH activity is important in the resynthesis of energy metabolites during reperfusion. In conclusion, prolonging the ischemic insult effected PDH activity during reperfusion, impaired recovery of energy metabolites, and worsened the recovery of rCBF.

Natural history and survival of 14 patients with corticobasal degeneration confirmed at postmortem examination

OBJECTIVE

To analyse the natural history and survival of corticobasal degeneration by investigating the clinical features of 14 cases confirmed by postmortem examination.

METHODS

Patients with definite corticobasal degeneration were selected from the research and clinical files of seven tertiary medical centres in Austria, the United Kingdom, and the United States. Clinical features were analysed in detail.

RESULTS

The sample consisted of eight female and six male patients; mean age at symptom onset was 63 (SD 7.7) years, and mean disease duration was 7.9 (SD 2.6) years. The most commonly reported symptom at onset included asymmetric limb clumsiness with or without rigidity (50%) or tremor (21%). At the first neurological visit, on average 3.0 (SD 1.9) years after symptom onset, the most often encountered extrapyramidal features included unilateral limb rigidity (79%) or bradykinesia (71%), postural imbalance (45%), and unilateral limb dystonia (43%). Ideomotor apraxia (64%), and to a lesser extent cortical dementia (36%), were the most common cortical signs present at the first visit. During the course of the disease, virtually all patients developed asymmetric or unilateral akinetic rigid parkinsonism and a gait disorder. No patient had a dramatic response to levodopa therapy. Median survival time after onset of symptoms was 7.9 (SD 0.7) (range, 2.5-12.5) years, and, after the first clinic visit, 4.9 (SD 0.7) (range, 0.8-10) years. Early bilateral bradykinesia, frontal syndrome, or two out of tremor, rigidity, and bradykinesia, predicted a shorter survival.

CONCLUSION

The results confirm that unilateral parkinsonism unresponsive to levodopa and limb ideomotor apraxia are the clinical hallmarks of corticobasal degeneration, and only a minority of patients with corticobasal degeneration present with dementia. The study also suggests that a focal cognitive and extrapyramidal motor syndrome is indicative of corticobasal degeneration. Survival in corticobasal degeneration was shortened by the early presence of (more) widespread parkinsonian features or frontal lobe syndrome.

Effect of nicardipine, a Ca2+ channel blocker, on pyruvate dehydrogenase activity and energy metabolites during cerebral ischemia and reperfusion in gerbil brain

The purpose of this study was to determine if nicardipine, a calcium ion channel blocker, affects pyruvate dehydrogenase (PDH) activity and improves energy metabolism during cerebral ischemia and reperfusion. Cerebral ischemia was induced, using the bilateral carotid artery occlusion method, for 60 min followed by reperfusion up to 120 min in gerbils. Nicardipine (1 mg/kg) or saline (vehicle-treated) was given to gerbils 30 min prior to the occlusion of the common carotid arteries. PDH activity and metabolites (ATP, PCr, and lactate) were measured in cortex prior to ischemia, immediately following ischemia, and after each reperfusion period. After 60 min ischemia, PDH activity increased in both groups, and was significantly higher in the nicardipine-treated group. After 20 min reperfusion, PDH activity in the nicardipine-treated group recovered to control levels, whereas, the PDH activity in the vehicle-treated group remained elevated, and was higher than the nicardipine-treated animals. At 60 and 120 min reperfusion, the activities in the vehicle-treated group were significantly below control levels, there were no differences, however, between the two groups. ATP and PCr concentrations were markedly depleted immediately after ischemia in both groups. ATP levels at 20 min reperfusion and PCr levels at 60 min reperfusion were significantly higher in the nicardipine-treated group. Lactate concentrations in both groups increased 7-8 fold, similarly, immediately after ischemia. During reperfusion, the lactate remained elevated in both groups, though the levels in the nicardipine-treated group were lower than those in the vehicle-treated group, but not significantly. Nicardipine treatment normalized PDH activity quickly and improved energy metabolism after reperfusion.

Comparative effects of clindamycin and ampicillin on superantigenic activity of Streptococcus pyogenes

We have tested the ability of Streptococcus pyogenes to produce streptococcal pyrogenic exotoxin A (SPEA) and superantigenic activity in the presence of sub-inhibitory concentrations of ampicillin and clindamycin. After 6 h of culture, SPEA production by S. pyogenes was higher in broths containing ampicillin (715.7 +/- 296.4 pg/10(6) cfu) than in broths containing clindamycin (167.1 +/- 31.9 pg/10(6) cfu), a difference that was not significant (P = 0.25). Promitogenic activity of bacterial supernatants was also greater in ampicillin-treated cultures (467.5 +/- 17.2 ccpm/10(6) cfu) than in clindamycin-treated cultures (169.2 +/- 8.9 ccpm/10(6) cfu), a difference that was highly significant (P = 0.0001). The data support the use of clindamycin in the treatment of streptococcal toxic shock-like syndrome, in order to inhibit superantigen synthesis.

What is the accuracy of the clinical diagnosis of multiple system atrophy? A clinicopathologic study

BACKGROUND

The presentation of symptoms for multiple system atrophy (MSA) varies. Because there are no specific markers for its clinical diagnosis, the diagnosis rests on the results of the neuropathologic examination. Despite several clinicopathologic studies, the diagnostic accuracy for MSA is unknown.

OBJECTIVES

To determine the accuracy for the clinical diagnosis of MSA and to identify, as early as possible, those features that would best predict MSA.

DESIGN

One hundred five autopsy-confirmed cases of MSA and related disorders (MSA [n=16], non-MSA [n=89]) were presented as clinical vignettes to 6 neurologists (raters) who were unaware of the study design. Raters identified the main clinical features and provided a diagnosis based on descriptions of the patients' first and last clinic visits.

METHODS

Interrater reliability was evaluated with the use of kappa statistics. Raters' diagnoses and those of the primary neurologists (who followed up the patients) were compared with the autopsy-confirmed diagnoses to estimate the sensitivity and positive predictive values at the patients' first and last visits. Logistic regression analysis was used to determine the best predictors to diagnose MSA.

RESULTS

For the first visit (median, 42 months after the onset of symptoms), the raters' sensitivity (median, 56%; range, 50%-69%) and positive predictive values (median, 76%; range, 61%-91%) for the clinical diagnosis of MSA were not optimal. For the last visit (74 months after the onset of symptoms), the raters' sensitivity (median, 69%; range, 56%-94%) and positive predictive values (median, 80%; range, 77%-92%) improved. Primary neurologists correctly identified 25% and 50% of the patients with MSA at the first and last visits, respectively. False-negative and -positive misdiagnoses frequently occurred in patients with Parkinson disease and progressive supranuclear palsy. Early severe autonomic failure, absence of cognitive impairment, early cerebellar symptoms, and early gait disturbances were identified as the best predictive features to diagnose MSA.

CONCLUSIONS

The low sensitivity for the clinical diagnosis of MSA, particularly among neurologists who followed up these patients in the tertiary centers, suggests that this disorder is underdiagnosed. The misdiagnosis of MSA is usually due to its confusion with Parkinson disease or progressive supranuclear palsy, thus compromising the research on all 3 disorders.

What are the obstacles for an accurate clinical diagnosis of Pick's disease? A clinicopathologic study

Several studies have evaluated the reliability and validity of the clinical diagnosis of Alzheimer's disease (AD) using well-defined neuropathologic criteria, but none has attempted to evaluate the diagnostic accuracy of Pick's disease. We determined the accuracy of the clinical diagnosis of Pick's by presenting 105 autopsy-confirmed cases of Pick's (n = 7) and related disorders (non-Pick's, n = 98) as clinical vignettes in randomized order to six neurologists who were unaware of the autopsy findings. The group of raters had moderate to fair agreement for the diagnosis of Pick's as measured by the kappa statistics. The sensitivity for the diagnosis of Pick's for the first visit (mean, 53 months after onset) and last visit (mean, 78 months after onset) was low (range, 0 to 71%), but specificity was near-perfect. Median positive predictive values at both visits were 83 to 85%. False-negative misdiagnoses mainly involved AD. False-positive diagnoses were rare and occurred with corticobasal degeneration (first visit) and with dementia with Lewy bodies (last visit). Pick's was also misdiagnosed by primary neurologists. The best clinical predictors for the early diagnosis of Pick's included "frontal" dementia, early "cortical" dementia with severe frontal lobe disturbances, absence of apraxia, and absence of gait disturbance at onset. However, the first neurologic evaluation in some of the Pick's cases took place in advanced stages of the disease. Our findings suggest that this disorder is underdiagnosed in clinical practice. Although the low sensitivity for the clinical diagnosis of Pick's is disappointing, our data suggest that when clinicians suspect Pick's, their diagnosis is almost always correct. Absence of awareness of the main features of this disorder and of specificity of the frontal lobe syndrome may partially explain the low detection of Pick's disease.

Ischemic tolerance phenomenon from an approach of energy metabolism and the mitochondrial enzyme activity of pyruvate dehydrogenase in gerbils

The objective of this study was to determine if the pretreatment with a sublethal ischemic insult, which has been shown to protect against delayed neuronal death, effects the recovery of energy metabolites or alters the activity of pyruvate dehydrogenase (PDH) following transient cerebral ischemia. Gerbils were pretreated with a sublethal ischemic insult, 2 min of bilateral common carotid artery occlusion, and 24 h later given a 5-min lethal ischemic insult. Animals were reperfused for 0, 10, or 60 min, or 1, 3 or 7 days. Brain metabolites, ATP, PCr, and lactate, and PDH activity were measured in the cortex and the hippocampal CA1 region. The pretreatment had no effect on ATP and PCr depletion or on lactate accumulation after the 5-min insult, nor on their recovery up to 1 day reperfusion, although there was a difference in the lactate levels of the non-pretreated and the pretreated gerbils after 10 min reperfusion. The pretreatment also had no effect on PDH activity during ischemia and reperfusion in either region. However, at 3 days reperfusion the non-pretreated animals exhibited a secondary decrease in ATP levels in the hippocampus. At 7 days reperfusion, ATP levels in the hippocampus of both the pretreated animals and the non-pretreated animals were significantly decreased compared to controls. Additionally, the level of ATP in the non-pretreated group was significantly lower than that in the pretreated group. The pretreatment with a sublethal ischemic insult did not effect the initial recovery of metabolites or the activity of PDH following transient cerebral ischemia. However, it protected against the secondary decrease of ATP levels in the hippocampus. Thus, the induction of ischemic tolerance is not caused by a reduction in metabolic impairment during the secondary insult.

Which clinical features differentiate progressive supranuclear palsy (Steele-Richardson-Olszewski syndrome) from related disorders? A clinicopathological study

The difficulty in differentiating progressive supranuclear palsy (PSP, also called Steele-Richardson-Olszewski syndrome) from other related disorders was the incentive for a study to determine the clinical features that best distinguish PSP. Logistic regression and classification and regression tree analysis (CART) were used to analyse data obtained at the first visit from a sample of 83 patients with a clinical history of parkinsonism or dementia confirmed neuropathologically, including PSP (n = 24), corticobasal degeneration (n = 11), Parkinson's disease (PD, n = 11), diffuse Lewy body disease (n = 14). Pick's disease (n = 8) and multiple system atrophy (MSA, n = 15). Supranuclear vertical gaze palsy, moderate or severe postural instability and falls during the first year after onset of symptoms classified the sample with 9% error using logistic regression analysis. The CART identified similar features and was also helpful in identifying particular attributes that separate PSP from each of the other disorders. Unstable gait, absence of tremor-dominant disease and absence of a response to levodopa differentiated PSP from PD. Supranuclear vertical gaze palsy, gait instability and the absence of delusions distinguished PSP from diffuse Lewy body disease. Supranuclear vertical gaze palsy and increased age at symptom-onset distinguished PSP from MSA. Gait abnormality, severe upward gaze palsy, bilateral bradykinesia and absence of alien limb syndorme separated PSP from corticobasal degeneration. Postural instability successfully classified PSP from Pick's disease. The present study may help to minimize the difficulties neurologists experience when attempting to classify these disorders at early stages.

Accuracy of the clinical diagnosis of corticobasal degeneration: a clinicopathologic study

The accuracy of the clinical diagnosis of corticobasal degeneration (CBD) is unknown. To determine its diagnostic accuracy, we presented 105 cases with known neuropathologic diagnoses, including CBD (n = 10), progressive supranuclear palsy (PSP, n = 24), Parkinson's disease (n = 15), diffuse Lewy body disease (n = 14), multiple system atrophy (n = 16), postencephalitic parkinsonism (n = 7), Pick's disease (n = 7), Creutzfeldt-Jakob disease (n = 4), Alzheimer's disease (n = 4), vascular parkinsonism (n = 3), and Whipple's disease (n = 1), as clinical vignettes to six neurologists unaware of the autopsy findings. Reliability was measured with the kappa statistics. The neurologists' clinical diagnoses were compared with clinicopathologic diagnoses for sensitivity, specificity, and positive predictive values at first and last clinic visits. The group reliability for the diagnosis of CBD significantly improved from moderate for the first visit (mean = 34 months after onset) to substantial for the last (68 months after onset). For the first visit, mean sensitivity for CBD was low (35%), but specificity was near-perfect (99.6%). For the last visit, mean sensitivity minimally increased (48.3%), and specificity remained stable. False-negative misdiagnoses mainly occurred with PSP. False-positive diagnoses were rare. The extremely low sensitivity of the clinical diagnosis of CBD suggests that this disorder is markedly underdiagnosed. Although the validity of the clinical diagnosis might have been improved if neurologists could have examined these patients, more important is that this disorder was misdiagnosed by the primary neurologists. In our data set, the best predictors for the diagnosis of CBD included limb dystonia, ideomotor apraxia, myoclonus, and asymmetric akinetic-rigid syndrome with late onset of gait or balance disturbances.