Clinical Characteristics of Myotonic Dystrophy with Associated Parkinsonism: An 11 Patients Case Series
Eduardo Inacio Nascimento Andrade1, kara Smith1
1Neurology, University of Massachusetts Chan Medical School
Objective:
To report a cases series describing the clinical characteristics of patient with Myotonic dystrophy (MD) and associated parkinsonism.
Background:
Rare case reports exist of patients with MD who develop concomitant parkinsonism, but limited epidemiologic and clinical data is available about these patients.
Design/Methods:
A PUBMED search was performed with the terms “Myotonic dystrophy parkinsonism”. Of 77 results, only nine represented case reports of MD and parkinsonism. Clinical characteristics of the cases were collected. One of the papers described two cases. One case from our institution, that is not yet published, was added to the analysis. A total of 11 patients were included in the analysis.
Results:
From the 11 patients included, 9 had genetic confirmation of MD
diagnosis. Among the 9 patients where a genetic test was available, 66% had Myotonic dystrophy type 1 and 33 % type 2. Patients were predominantly female (72%). The mean age of initial MD symptoms was 49, and of parkinsonism 50 years (range 25-67). 45 % of patients developed MD symptoms first, while 27 % experienced parkinsonism first and 27 % developed both types of symptoms concomitantly. With regards to parkinsonism, 60 % had an asymmetric presentation. The response to levodopa was absent in 27 %, minimal in 36 % and good in 36 %. 6 patients had Dopamine transporter image available, with 5 showing abnormalities in the basal ganglia and 1 in the superior temporal gyrus, parietal operculum, and posterior thalamus.
Conclusions:
Patients with MD and parkinsonism seem to be predominantly female and more commonly have MD type 1. Although the majority of dopamine transporter scan was abnormal, there is more variability in levodopa response than expected compared to idiopathic Parkinson’s disease. Our findings will inform awareness and screening for parkinsonism in the MD population, and guide clinicians on management and prognosis of this intersection of conditions.