[A 63-year-old woman with muscle weakness, myotonia, and parkinsonism].No To Shinkei. 1996 Mar; 48(3):287-97.NT
We report a 63-year-old woman who presented myotonia and parkinsonism. The patient was well until 15 years of the age when she noted that the ring finger of her left hand at times flexed when she did not intend to do so. She noted weakness in her left upper extremity at the age of 40, and difficulty in relaxing her hand grip at 45. She had an onset of tremor in her right foot at age 50, which was followed by difficulty in gait and hand writing. She was admitted to Juntendo University Urayasu Hospital when she was 63-year-old. Her mother, two sisters, and a son were affected with similar muscle weakness and myotonia. Although some of them developed stooped posture in the late stage of the disease, none of them had overt parkinsonism. General physical examination was unremarkable. Neurologic examination revealed an alert and oriented woman with some recent memory loss. She had bilateral ptosis, facial weakness, and a masked face. Myerson's sign was present. Her speech was small and monotonous. The sternocleidomastoid muscles were markedly atrophic and weak. The remaining of the cranial nerves were intact. She walked in small steps with freezing with support. She showed bradykinesia, retropulsion, and resting tremor in her right leg. Slight distal dominant weakness was noted in both upper and lower extremities more on the left. No cerebellar signs were noted. Muscle stretch reflexes were within normal limits in the upper extremities and diminished in the lower limbs. Sensation was intact. Routine laboratory findings were unremarkable. Cranial CT scan and MRI revealed slight cortical atrophy and leukoaraiosis. She responded to levodopa and she became able to walk by herself. She was transferred to another hospital one month after her admission. She had several bouts of airway obstruction with one episode of respiratory arrest. She expired six month after the transfer. The patient was discussed in a neurological CPC, and the chief discussant arrived at the conclusion that this patient suffered from myotonic dystrophy and Parkinson's disease which set in later years. Postmortem examination on the iliopsoas muscle revealed uneven muscle fiber diameters, central nuclei, and type 1 fiber predominance; the pathologic finding was consistent with myotonic dystrophy. The substantia nigra showed marked cell loss and Lewy bodies in the remaining neurons. The finding was consistent with Parkinson's disease. In myelin stain, diffuse myelin pallor was noted in the cerebral white matter which was the pathologic substrate of leukoaraiosis in this patient. Combination of these two disorders have never been reported in the literature to our knowledge. It appears to be that the coincidence is just a by-chance phenomenon, but it seems interesting to note that accelerated aging process appears to be present in both myotonic dystrophy and Parkinson's disease.