***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: Dementia with Lewy Bodies ( DLB ) was initially identified and confirmed primarily by pathology , but is soon to be incorporated into the Diagnostic and Statistical Manual criteria as a clinical disease entity . Despite these advances over more than 20 years , current data suggest that the sensitivity of accurate clinical diagnosis of DLB is still very low , although there is mounting evidence that supportive features may increase diagnostic accuracy . Although DLB remains easy to identify pathologically with different cellular pathologies differentiating it from other dementia syndromes , pathological identification using only Lewy body pathology has been shown to be inaccurate due to overlap with patients without dementia symptoms . A number of studies now suggest that a combination of cellular pathologies , which include α-synuclein and β-amyloid deposition as well as dopamine denervation , assist with differentiating this dementia syndrome from others . The clinical and pathological overlap with the tauopathy of Alzheimer ’s disease still remains to be clarified . To determine more robust and independent clinicopathological correlates from Alzheimer ’s disease , longitudinal prospect i ve studies , using specific clinical batteries on dementia patients reaching the proposed criteria for DLB , with post-mortem assessment of the multiple pathologies associated with dementia , are required . Identifying genetic causes for DLB is another approach to investigate the pathogenesis of DLB . However this approach has been hindered to date by difficulties with identifying DLB clinical ly . The use of novel techniques is likely to advance knowledge on the pathogenesis of DLB and assist with redefining clinical and pathologic diagnostic criteria . To achieve the goal of more accurate clinical diagnosis of DLB , breakthroughs are necessary on the pathogenesis of DLB We have review ed the clinical and pathological diagnoses of 143 cases of parkinsonism seen by neurologists associated with the movement disorders service at The National Hospital for Neurology and Neurosurgery in London who came to neuropathological examination at the United Kingdom Parkinson 's Disease Society Brain Research Centre , over a 10-year period between 1990 and the end of 1999 . Seventy-three ( 47 male , 26 female ) cases were diagnosed as having idiopathic Parkinson 's disease ( IPD ) and 70 ( 42 male , 28 female ) as having another parkinsonian syndrome . The positive predictive value of the clinical diagnosis for the whole group was 85.3 % , with 122 cases correctly clinical ly diagnosed . The positive predictive value of the clinical diagnosis of IPD was extremely high , at 98.6 % ( 72 out of 73 ) , while for the other parkinsonian syndromes it was 71.4 % ( 50 out of 70 ) . The positive predictive values of a clinical diagnosis of multiple system atrophy ( MSA ) and progressive supranuclear palsy ( PSP ) were 85.7 ( 30 out of 35 ) and 80 % ( 16 out of 20 ) , respectively . The sensitivity for IPD was 91.1 % , due to seven false-negative cases , with 72 of the 79 pathologically established cases being diagnosed in life . For MSA , the sensitivity was 88.2 % ( 30 out of 34 ) , and for PSP it was 84.2 % ( 16 out of 19 ) . The diagnostic accuracy for IPD , MSA and PSP was higher than most previous prospect i ve clinicopathological series and studies using the retrospective application of clinical diagnostic criteria . The seven false-negative cases of IPD suggest a broader clinical picture of disease than previously thought acceptable . This study implies that neurologists with particular expertise in the field of movement disorders may be using a method of pattern recognition for diagnosis which goes beyond that inherent in any formal set of diagnostic criteria Background : The long-term effectiveness of three different initial drug regimes in patients with early , mild PD was evaluated by the PD Research Group of the United Kingdom ( PDRGUK ) . In 1995 , the selegiline arm of the trial was terminated following an interim analysis . Method : This was an open , r and omized trial . Between 1985 and 1990 , 782 patients with de-novo PD were recruited and r and omized to one of three treatment arms : levodopa plus dopa decarboxylase inhibitor ; levodopa plus decarboxylase inhibitor and selegiline ; or bromocriptine . The main endpoints were mortality , disability , and adverse events . Intention-to-treat analysis was used . Results : There was no significant difference in mortality between the bromocriptine and the levodopa arms ( hazard ratio 1.15 [ 95 % CI 0.90 , 1.47 ] ) . Patients initially r and omized to bromocriptine had slightly worse disability scores throughout follow-up . This difference was significant during the first years . Patients in the bromocriptine arm returned to pretreatment disability levels one year earlier than those in the levodopa arm . Patients r and omized to bromocriptine had a significantly lower incidence of dyskinesias than those r and omized to levodopa ( rate ratio 0.73 [ 95 % CI 0.57 , 0.93 ] ) . However , this difference was not significant when only moderate to severe dyskinesias were considered . Patients in the bromocriptine arm had slightly lower rates of dystonias and on-off fluctuations , but moderate and severe forms were equally frequent in both arms . Conclusion : Starting treatment with the dopamine agonist bromocriptine does not reduce mortality in PD . A slightly lower incidence of motor complications is achieved at the expense of significantly worse disability scores throughout the first years of therapy Few detailed clinico-pathological correlations of Parkinson 's disease have been published . The pathological findings in 100 patients diagnosed prospect ively by a group of consultant neurologists as having idiopathic Parkinson 's disease are reported . Seventy six had nigral Lewy bodies , and in all of these Lewy bodies were also found in the cerebral cortex . In 24 cases without Lewy bodies , diagnoses included progressive supranuclear palsy , multiple system atrophy , Alzheimer 's disease , Alzheimer-type pathology , and basal ganglia vascular disease . The retrospective application of recommended diagnostic criteria improved the diagnostic accuracy to 82 % . These observations call into question current concepts of Parkinson 's disease as a single distinct morbid entity Overdiagnosis of Parkinson 's disease ( PD ) is suggested by specialist review of community diagnosis , and in postmortem studies . In specialist centers 4 to 15 % of patients entered into clinical trials as early PD do not have functional imaging support for a PD diagnosis . In a European multicenter , prospect i ve , longitudinal study , we compared clinical diagnosis with functional SPECT imaging using [123I]FP-CIT ( DaTSCAN , GE Healthcare ) . Repeat observations were performed over 3 years in patients with tremor and /or parkinsonism in whom there was initial diagnostic uncertainty between degenerative parkinsonism and nondegenerative tremor disorders .  Video-recording of clinical features was scored independently of functional imaging results by two blinded clinicians at 36 months (= gold st and ard clinical diagnosis ) . Three readers , unaware of the clinical diagnosis , classified the images as normal or abnormal by visual inspection . The main endpoint was the sensitivity and specificity of SPECT imaging at baseline compared with the gold st and ard . In 99 patients completing the three serial assessment s , on-site clinical diagnosis overdiagnosed degenerative parkinsonism at baseline in diagnostically uncertain cases compared with the gold st and ard clinical diagnosis ( at 36 months ) , the latter giving a sensitivity of 93 % and specificity of 46 % . The corresponding baseline [123I]FP-CIT SPECT results showed a mean sensitivity of 78 % and a specificity of 97 % . Inter-reader agreement for rating scans as normal or abnormal was high ( Cohen 's kappa = 0.94 - 0.97 ) Background This study examines the clinical accuracy of movement disorder specialists in distinguishing tremor dominant Parkinson 's disease ( TDPD ) from other tremulous movement disorders by the use of st and ardised patient videos . Patients and methods Two movement disorder specialists were asked to distinguish TDPD from patients with atypical tremor and dystonic tremor , who had no evidence of presynaptic dopaminergic deficit ( subjects without evidence of dopaminergic deficit ( SWEDDs ) ) according to 123I-N-ω-fluoro-propyl- 2β-carbomethoxy-3β-(4-iodophenyl ) nortropane ( [ 123I ] FP-CIT ) single photon emission computed tomography ( SPECT ) , by ‘ blinded ’ video analysis in 38 patients . A diagnosis of parkinsonism was made if the step 1 criteria of the Queen Square Brain Bank criteria for Parkinson 's disease were fulfilled . The review er diagnosis was compared with the working clinical diagnosis drawn from the medical history , SPECT scan result , long term follow-up and in some cases the known response to dopaminergic medications . This comparison allowed a calculation for false positive and false negative rate of diagnosis of PD . Results High false positive ( 17.4 - 26.1 % ) and negative ( 6.7 - 20 % ) rates were found for the diagnosis of PD . The diagnostic distinction of TDPD from dystonic tremor was reduced by the presence of dystonic features in treated and untreated PD patients . Conclusion Clinical distinction of TDPD from atypical tremor , monosymptomatic rest tremor and dystonic tremor can be difficult due to the presence of parkinsonian features in tremulous SWEDD patients . The diagnosis of bradykinesia was particularly challenging . This study highlights the difficulty of differentiation of some cases of SWEDD from PD BACKGROUND Parkinson 's disease is a common disorder among older people . Accurate epidemiological information is essential to identify possible aetiological factors , plan health services and set priorities for medical research . OBJECTIVE to determine the incidence of idiopathic Parkinson 's disease in a defined geographical area in the North-East of Engl and . METHODS using a prospect i ve , longitudinal design , we sought to identify every new case of Parkinson 's disease arising in the Newcastle and Gateshead area in the North-East of Engl and . The base population comprised 488 576 individuals and multiple sources of case ascertainment were employed . All the patients with newly diagnosed idiopathic Parkinson 's disease or parkinsonism between 1 June 2009 and 31 May 2011 were invited to participate . Patients were examined by a specialist and followed longitudinally to permit diagnostic review . RESULTS we identified 257 potential cases , of whom 181 had suspected idiopathic Parkinson 's disease . After a follow-up period of 18 months , 155 patients retained a clinical diagnosis of probable Parkinson 's disease . The  mean age at diagnosis was 72.4 ± 10 years . The crude incidence of PD in Newcastle and Gateshead was 15.9 per 100 000 persons per year ( 95 % CI : 13.4 - 18.4 ) . Age-st and ardised to the European population the incidence of Parkinson 's disease was 12.0 per 100 000 ( 95 % CI : 10.1 - 14.0 ) . We found a higher crude incidence among men 17.7 per 100 000 ( 95 % CI : 14.0 - 21.4 ) than women 14.0 per 100 000 ( 95 % CI : 10.7 - 17.4 ) . CONCLUSION in this prospect i ve longitudinal study , the incidence rate of Parkinson 's disease in North-East Engl and is similar to that of other modern European and American studies CONTEXT Since there is no diagnostic biological marker for Parkinson disease ( PD ) , the diagnosis is based on the results of clinical assessment . The accuracy of diagnosis improves with time and repeated assessment s. Studies that require only inclusion of early cases of PD present a diagnostic challenge . Previous studies concluded that initial diagnoses of PD made by general neurologists were incorrect in 24 % to 35 % of the cases when patients were examined at autopsy . Experts in movement disorders are expected to have greater accuracy of initial diagnosis of PD . OBJECTIVE To determine the evolution of clinical diagnosis in patients with early PD made initially by experts in PD . DESIGN Eight hundred patients with mild parkinsonian symptoms ( Hoehn and Yahr stage 1 or 2 ) who received a diagnosis of PD less than 5 years before the beginning of the study were included in the original Deprenyl and Tocopherol Antioxidative Therapy for Parkinson 's Disease study . These patients were followed up prospect ively with repeated clinical assessment s. The following clinical criteria were used to reassess the initial diagnosis : investigator 's confidence in the diagnosis of PD , presence of atypical clinical features , findings of imaging studies , response to levodopa , and results of  autopsy examinations . RESULTS The mean + /- SD duration of illness in the 800 cases at enrollment was 2.2+/-1.3 years , and the mean + /- SD Hoehn and Yahr stage was 1.6+/-0.5 . The mean + /- SD follow-up was 6.0+/-1.4 years ( range , 0.2 - 7.6 years ) . In 5 cases , PD was not confirmed at autopsy , and in 15 patients , the results of imaging studies indicated the presence of other path 
    Output:
    
Conclusion : The overall validity of clinical diagnosis of PD is not satisfying .
The accuracy did not significantly improve in the last 25 years , particularly in the early stages of disease , where response to dopaminergic treatment is less defined and hallmarks of alternative diagnoses such as atypical parkinsonism may not have emerged .