Motor score of the Unified Parkinson Disease Rating Scale as a good predictor of Lewy body-associated neuronal loss in the substantia nigra.
BACKGROUND
How well the motor symptoms assessed by the motor section of the Unified Parkinson Disease Rating Scale (UPDRS3) reflect the neuronal loss observed in the substantia nigra is not known.


OBJECTIVE
To study the relationships among the motor symptoms assessed by the UPDRS3, Lewy body-associated neuronal loss in the substantia nigra, and duration of disease.


METHODS
Longitudinal, prospective, clinicopathological study.


METHODS
Long-term care facility of a university hospital.


METHODS
Eighteen elderly patients with a parkinsonian syndrome, studied prospectively but selected post mortem on the basis of the presence of Lewy bodies, and 5 age-matched control subjects.


METHODS
One map of a section of the substantia nigra, indicating the location of all the nucleolated neuronal profiles, was drawn for each case. Neuronal density was estimated using a tessellation method. The relationship between time and neuronal loss and between neuronal loss and motor symptoms (assessed by the UPDRS3) was studied by means of regression analysis, using linear and exponential models.


RESULTS
The neuronal density was linearly linked with the UPDRS3 score (r = -0.83 [P<.001]). Each point added to the UPDRS3 score corresponded to an estimated loss of 25 neurons/mm(3). The density of neuronal profiles in the substantia nigra decreased exponentially with time (r = -0.73 [P<.001]). Extrapolation of the curve suggested a presymptomatic phase of 5 years.


CONCLUSIONS
The UPDRS3 score is linearly linked to neuronal density, which, in Lewy body diseases, decreases exponentially with time at a similar pace in this series of elderly patients and in the younger patients described in the literature.
Greffard
Sandrine
S
Geriatric Center, Pitié-Salpêtrière Hospital, Assistance Publique des Hôpitaux de Paris, 47 Boulevard de l'Hôpital, 75651 Paris CEDEX 13, France.
Verny
Marc
M
Bonnet
Anne-Marie
AM
Beinis
Jean-Yves
JY
Gallinari
Claude
C
Meaume
Sylvie
S
Piette
François
F
Hauw
Jean-Jacques
JJ
Duyckaerts
Charles
C
D000368:Aged; D000369:Aged, 80 and over; D002452:Cell Count; D005260:Female; D006801:Humans; D016631:Lewy Bodies / Q000378:metabolism / Q000473:pathology*; D020961:Lewy Body Disease / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology; D008137:Longitudinal Studies; D008297:Male; D009068:Movement / Q000502:physiology; D009410:Nerve Degeneration / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D009460:Neurologic Examination; D009474:Neurons / Q000378:metabolism / Q000473:pathology*; D020734:Parkinsonian Disorders / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013223:Statistics as Topic; D013378:Substantia Nigra / Q000473:pathology* / Q000503:physiopathology