Anterior temporal white matter lesions in adult-form myotonic dystrophy type 1

Lesões temporais anteriores da substância branca na forma adulta da distrofia miotônica tipo 1

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).

Figure 1
Dystrophy and sequence of myotonia in left hand.

Figure 2
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 involvement^1,2. Anterior temporal lobe subcortical white matter lesions are described in DM1, but not in DM2 patients³. Limbic encephalitis and CADASIL are the most important imaging differential diagnosis.

References

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  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
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  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
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  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
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Publication Dates

• Publication in this collection
  Nov 2014

History

• Received
  02 Apr 2014
• Reviewed
  22 July 2014
• Accepted
  01 Aug 2014