Affiliations: Department of Behavioral Neurology and Cognitive
Neuroscience, Tohoku University Graduate School of Medicine, Sendai,
Japan | Department of Neurosurgery, National Hospital
Organization, Shizuoka Medical Center, Shizuoka, Japan | Department of Cardiovascular Surgery, National
Hospital Organization, Shizuoka Medical Center, Shizuoka, Japan | Department of Neurology, Numazu Rehabilitation
Hospital, Numazu, Japan
Note: [] Corresponding author: Nobuhito Abe, Department of Behavioral
Neurology and Cognitive Neuroscience, Tohoku University Graduate School of
Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan. Tel.: +81 22 717
7358; Fax: +81 22 717 7360; E-mail: abe-n@mail.tains.tohoku.ac.jp
Abstract: We describe a patient with Marchiafava-Bignami disease who showed,
in addition to signs of callosal interruption, a peculiar form of diagonistic
dyspraxia. Unlike the typical diagonistic dyspraxia, both of the patient's
hands could simultaneously cooperate in a sequence of bimanual actions. More
specifically, his right hand could start a commanded action with the
cooperation of his left hand. However, once the action was completed, his left
hand started an antagonistic action, undoing the result, with the cooperation
of his right hand. Once this countermanding action was completed, the original
action started again. These antagonistic actions repeated themselves
alternately unless he was restrained. The patient's diagonistic dyspraxia was
apparent in only some bimanual actions, and he showed no diagonistic dyspraxia
when performing voluntary actions; the antagonistic actions occurred in
response to oral commands or by imitation. Magnetic resonance imaging showed
symmetrical demyelination with partial necrosis in the genu, body, and anterior
splenium of the corpus callosum. We speculate that the bimanual coordination is
possible because part of the corpus callosum is intact, whereas the
antagonistic actions may be caused by conflict between the two hemispheres due
to interhemispheric disinhibition elicited by the demyelinated part of the
corpus callosum.
Keywords: Corpus callosum, diagonistic dyspraxia, Marchiafava-Bignami disease
