The Japanese journal of neuropsychology

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ArticleTitle	Releasing phenomena of well learned praxes observed in the right hand following occlusion of the right anterior and middle cerebral arteries
Language	J
AuthorList	Kenji Ishihara^/, Mitsuru Kawamura, Toshiyuki Maki**
Affiliation	Department of Neurology, Showa University School of Medicine *Department of Neurology, Kameda General Hospital
Publication	Japanese Journal of Neuropsychology: 16 (1), 25-31, 2000
Received	Feb 10, 1999
Accepted	Sep 28, 1999
Abstract	We describe a patient who presented with manipulation of tools in the right hand following a right hemispheric lesion. An 85-year-old right-handed female was admitted with an acute onset of left hemiparesis and dysarthria. Cerebral angiography demonstrated occlusion of the right anterior and middle cerebral arteries. MRI revealed infarction in medial side of the right frontal lobe, the right superior frontal gyrus and anterior part of the corpus callosum. HMPAO-SPECT scan revealed decreased blood flow in the right cerebral hemisphere. About seven weeks after admission, she showed pathological grasping phenomena (grasping reflex and instinctive grasping reaction) in the right hand. Moreover, when such tools as a hairbrush and a towel were presented, she used them correctly with her right hand without waiting for any instructions by the examiner. Even if she was instructed not to use the tools, two events occured: (1) she immediately used the tools, or (2) she moved her right hand away from the tools intentionally, but then her right hand approached them gradually, and finally she used them against her will. She could not inhibit the movement of her right hand voluntarily. Manipulation of tools observed in this case manifested some compulsive features and might be considered to have some characteristics of both "utilization behavior" (Lhermitte, 1983) and "compulsive manipulation of tools" (Mori et al, 1982), which reinforces the idea that utilization behavior and compulsive manipulation of tools may be considered as one phenomenon, "releasing phenomena of well learned praxes" (Takahashi et al, 1991). The present case is of interest because the lesion involved only the right hemisphere including anterior part of the corpus callosum and compulsive features were associated with the manipulation of tools. Compulsive manipulation of tools with the right hand has not been described in patients with a right hemispheric lesion. Moreover the present case suggests that manipulation of tools and pathological grasping phenomena following a right hemispheric lesion may share a common mechanism.
Keywords	compulsive manipulation of tools, utilization behavior, releasing phenomena of well learned praxes, right hemispheric lesion, callosal lesion