Acute Challenge with Apomorphine and Levodopa in Parkinsonism.
Background: The diagnosis of different parkinsonian
syndromes and the ability to predict long-term drug
efficacy constitute important clinical issues.
Design: Motor responses to the acute administration
of levodopa and apomorphine were analyzed in a series
of 134 parkinsonian patients, including 83 patients
with a clinical diagnosis of idiopathic Parkinson's
disease (PD), 28 patients with multiple-system
atrophy (MSA), 6 with progressive supranuclear palsy,
and 17 with an unclassified parkinsonian syndrome.
Methods: The patients received oral
levodopa/carbidopa (250/25 mg) and subcutaneous
apomorphine (1.5, 3 and 4.5 mg). Clinical variations
of the Unified Parkinson's Disease Rating Scale
(UPDRS) motor score were evaluated 1 h following
levodopa administration or 20 min following
apomorphine. The motor improvement produced by each
acute challenge was matched with the clinical
diagnosis and with the response to chronic levodopa
treatment. The diagnosis was verified by repeated
clinical assessments or by autopsy in 2 cases. A
receiver operating characteristics curve was plotted
comparing PD vs. non-PD, PD vs. MSA and chronic
responders vs. nonresponders. Cutoff threshold
improvement was defined as the value closest to the
crossing point for 80% sensitivity and 80%
specificity, corresponding to the best trade-off for
a predictive evaluation. Results: UPDRS motor score
improvement was on average higher in PD than in
non-PD patients (levodopa: 29.8 vs. 12.2%;
apomorphine 1.5 mg: 27.1 vs. 10.5%; apomorphine 3 mg:
27.7 vs. 9.7%; apomorphine 4.5 mg: 28.8 vs. 11.8%; p
< 0.01 with Student's t test). When PD patients were
compared to non-PD patients, levodopa challenge had
the best diagnostic accuracy with a threshold
improvement of 16%. Apomorphine had the best
diagnostic accuracy with a threshold improvement of
13.5% for 1.5 mg, 13% for 3 mg, and 16% for 4.5 mg.
This meant that patients improving at least 16% in
all tests had the highest probability of having PD.
When PD patients were compared to MSA patients,
levodopa acute challenge had the best diagnostic
accuracy with a threshold improvement of 17%.
Apomorphine had the best diagnostic accuracy with an
improvement of 13% for 1.5 mg, 15% for 3 mg, and 18%
for 4.5 mg. This meant that patients improving at
least 18% in all tests had the highest probability of
having PD rather than MSA. When patients who
responded to chronic levodopa treatment were compared
to those who did not, acute challenge with levodopa
had the best predictive accuracy with a threshold
improvement of 14.5%. Apomorphine had the best
predictive accuracy with an improvement of 13% for
1.5 mg, and 14% for 3 and 4.5 mg. This meant that
patients improving at least 14.5% in all tests had
the highest probability of responding to chronic
treatment. Conclusion: A good agreement was found
between acute challenges with levodopa/carbidopa and
apomorphine, and the use of both improved the
reliability of the test. Different threshold
improvements after acute challenges would support a
diagnosis of PD or the exclusion of MSA, and would
have a predictive value for subsequent response to
chronic levodopa therapy. Copyright 2000 S. Karger
AG, Basel
Eur Neurol 2000 Feb;43(2):95-101
Rossi P, Colosimo C, Moro E, Tonali P, Albanese A
Istituto di Neurologia, Universita Cattolica del Sacro Cuore, Roma, Italia.
PMID: 10686467
<http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10686467&dopt=Abstract>
janet paterson
52 now / 41 dx / 37 onset
a new voice: http://www.geocities.com/janet313/
613 256 8340 PO Box 171 Almonte Ontario Canada K0A 1A0
