Utility of the new Movement Disorder Society clinical diagnostic criteria for Parkinson's disease applied retrospectively in a large cohort study of recent onset cases.
OBJECTIVE
To examine the utility of the new Movement Disorder Society (MDS) diagnostic criteria in a large cohort of Parkinson's disease (PD) patients.


METHODS
Recently diagnosed (<3.5 years) PD cases fulfilling United Kingdom (UK) brain bank criteria in Tracking Parkinson's, a UK multicenter prospective natural history study were assessed by retrospective application of the MDS criteria.


RESULTS
In 2000 cases, 1835 (91.7%) met MDS criteria for PD, either clinically established (n = 1261, 63.1%) or clinically probable (n = 574, 28.7%), leaving 165 (8.3%) not fulfilling criteria. Clinically established cases were significantly more likely to have limb rest tremor (89.3%), a good l-dopa response (79.5%), and olfactory loss (71.1%), than clinically probable cases (60.6%, 44.4%, and 34.5% respectively), but differences between probable PD and 'not PD' cases were less evident. In cases not fulfilling criteria, the mean MDS UPDRS3 score (25.1, SD 13.2) was significantly higher than in probable PD (22.3, SD 12.7, p = 0.016) but not established PD (22.9, SD 12.0, p = 0.066). The l-dopa equivalent daily dose of 341 mg (SD 261) in non-PD cases was significantly higher than in probable PD (250 mg, SD 214, p < 0.001) and established PD (308 mg, SD 199, p = 0.025). After 30 months' follow-up, 89.5% of clinically established cases at baseline remained as PD (established/probable), and 86.9% of those categorized as clinically probable at baseline remained as PD (established/probable). Cases not fulfilling PD criteria had more severe parkinsonism, in particular relating to postural instability, gait problems, and cognitive impairment.


CONCLUSION
Over 90% of cases clinically diagnosed as early PD fulfilled the MDS criteria for PD. Those not fulfilling criteria may have an atypical parkinsonian disorder or secondary parkinsonism that is not correctly identified by the UK Brain Bank criteria, but possibly by the new criteria.
['Malek|Naveed|N|', 'Lawton|Michael A|MA|', 'Grosset|Katherine A|KA|', 'Bajaj|Nin|N|', 'Barker|Roger A|RA|', 'Ben-Shlomo|Yoav|Y|', 'Burn|David J|DJ|', 'Foltynie|Tom|T|', 'Hardy|John|J|', 'Morris|Huw R|HR|', 'Williams|Nigel M|NM|', 'Wood|Nicholas|N|', 'Grosset|Donald G|DG|', '|||']
D000368:Aged D001921:Brain D060825:Cognitive Dysfunction D005260:Female D006801:Humans D007980:Levodopa D008297:Male D008875:Middle Aged D009483:Neuropsychological Tests D010300:Parkinson Disease D012189:Retrospective Studies D012720:Severity of Illness Index D006113:United Kingdom
Criteria Parkinson's disease Diagnosis Phenotype