A 57-year-old woman presented with a 4-years history of progressive weakness, distal muscular atrophy and myotonia in left hand (Figure 1). Her electromyography had a myotonic pattern. Patient was first diagnosed as paraneoplasic limbic encephalitis based on her brain MRI (Figure 2). Diagnosis was genetically confirmed for myotonic dystrophy type 1 (DM1).
MRI (T2 weight coronal and axial slices) showing bilateral anterior temporal hypersignal in our case. Notice that mesial temporo-limbic structures are not affected.
DM1 or Steinert's disease is an autosomal-dominant disorder characterized by muscle
weakness and unusual features, compared with other dystrophies, including myotonia,
anticipation, and multiple organ involvement11 . Meola G, Sansone V. Cerebral involvement in myotonic dystrophies.
Muscle Nerve. 2007;36(3):294-306.
http://dx.doi.org/10.1002/mus.20800
https://doi.org/10.1002/mus.20800...
,22 . Machuca-Tzili L, Brook D, Hilton-Jones D. Clinical and molecular
aspects of the myotonic dystrophies: a review. Muscle Nerve 2005;32(1):1-18.
http://dx.doi.org/10.1002/mus.20301
https://doi.org/10.1002/mus.20301...
.
Anterior temporal lobe subcortical white matter lesions are described in DM1, but not in
DM2 patients33 . Kornblum C, Reul J, Kress W, Grothe C, Amanatidis N, Klockgether T
et al. Cranial magnetic resonance imaging in genetically proven myotonic
dystrophy type 1 and 2. J Neurol. 2004;251(6):710-4.
http://10.1007/s00415-004-0408-1
https://doi.org/10.1007/s00415-004-0408-...
. Limbic encephalitis and
CADASIL are the most important imaging differential diagnosis.
References
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1Meola G, Sansone V. Cerebral involvement in myotonic dystrophies. Muscle Nerve. 2007;36(3):294-306. http://dx.doi.org/10.1002/mus.20800
» https://doi.org/10.1002/mus.20800 -
2Machuca-Tzili L, Brook D, Hilton-Jones D. Clinical and molecular aspects of the myotonic dystrophies: a review. Muscle Nerve 2005;32(1):1-18. http://dx.doi.org/10.1002/mus.20301
» https://doi.org/10.1002/mus.20301 -
3Kornblum C, Reul J, Kress W, Grothe C, Amanatidis N, Klockgether T et al. Cranial magnetic resonance imaging in genetically proven myotonic dystrophy type 1 and 2. J Neurol. 2004;251(6):710-4. http://10.1007/s00415-004-0408-1
» https://doi.org/10.1007/s00415-004-0408-1
Publication Dates
-
Publication in this collection
Nov 2014
History
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Received
02 Apr 2014 -
Reviewed
22 July 2014 -
Accepted
01 Aug 2014