NOTE FAILURE TO MANIPULATE OBJECTS SECONDARY TO ACTIVE TOUCH DISTURBANCE Naoyasu Motomura1, Atsushi Yamadori2, Hiroyuki Asaba1, Toshiaki Sakai 1 and Tohru Sawada3 (1Department of Neuropsychiatry, Osaka Medical College; 2Neurology Service, Hyogo Brain and Heart Center at Himeji; 3Division of Internal Medicine, National Cardiovascular Center) In animal experiments there are many evidences of motor clumsiness secondary to cortical sensory disturbance (Cole and Glees, 1953; Peel, 1944; Kruger, 1958; Hikosaka, Tanaka, Sakamoto and Iwamura, 1985). However, in human beings relatively few cases of contralateral clumsiness secondary to higher sensory disturbance have been reported. Moreover, these patients do not show the same pattern of sensory disturbance and it is controversial what type of sensory disturbance influences contralateral motor clumsiness. Lange (1936) mentioned that patients withtactile agnosia not rarely have slight motor disturbances. Luria (1966) reported clumsiness associated with damage of postcentral gyrus and stressed that it was conseguent to loss of kinaesthetic sensation. Jeannerod et al. (1984) described motor clumsiness secondary to cortical anesthesia and emphasized the role of somatosensory cortex in conveying kinaesthetic input to the motor areas. Yamadori (1982) reported a case characterized by clumsy palpatory finger movement and normal non-palpatory finger movement under visual guidance and attributed it to the functional impairment of a higher-order sensory system. We encountered a case of clumsy palpatory finger movements with a circumscribed lesion in the contralateral postcentral gyrus. Detailed evaluation of the case led to conclusions ·similar to those of Yamadori. CASE REPORT A 45-year-old right-handed woman suddenly developed left sided hemiparesis on April 22, 1965, due to an infarction of the middle cerebral artery. The left hemiparesis gradually subsided, but clumsiness of the left hand persisted. Although she could move well the left fingers, she found it difficult to manipulate objects. On September 22, 1985, she suddenly developed numbness in her left hand and was referred to Osaka Medical College Hospital. On examination, she showed no apparent weakness on either side of the body. Tone was normal, no involuntary movement was observed, deep tendon reflexes were equal bilaterally and pathological reflexes were not elicited. Cranial nerves were intact. No cerebellar sign was noted. The left hand was clumsy in all manual activities. Sensory function of the left hand was preserved in primary modalities but was defective in some of the discriminative tasks (see later). The right hand was normal in all respects, writing and drawing included. The patient had no aphasia and she showed neither ideomotor nor ideational apraxia with both hands. On the Wechsler Adult Intelligence Test verbal IQ was 135; performance IQ 126; and total IQ 133. Motor Status of the Left Hand She had difficulty in manipulating objects, such as in buttoning, putting on gloves, turning a page of a book or holding a coin, without visual help. She could not pick up an object, such as a pencil eraser, from a funnel or a hole. Cortex, (1990) 26, 473-477 474 N. Motomura and Others Fig. I - Computed tomography of the brain revealed a strip-like high density lesion in the right central area (arrows). Imitation of non-meaningful finger movement. The following movements were possible: Opposing movement of the thumb with each of the other fingers, abduction and adduction of individual fingers, extention and flexion of individual fingers, pronation and supination of the forearm, placing the middle finger on the index finger. Imitation of the following finger patterns shown by the examiner was correct: Extention of the second and the third finger with flexion of other fingers, making a ring with the thumb and the index finger, extension of the thumb and the little finger with flexion of the other fingers. Dynamic coordination (Luria, 1966). The'fist-ring' test and 'fist-edge-palm' test were performed well with the right hand, but were clumsily with the left. They were carried out under vision. Active touch, motor clumsiness 475 Fig. 2 - Magnetic resonance imaging of the brain by Tl imagings (TR600, TE30). On axial section the low signal intensity area was found in the postcentral gyrus (arrows: lesions). Fig. 3 - Magnetic resonance imaging of the brain by T2 imagings (TR2000, TE30). On sagittal section a low signal intensity area was confirmed in the postcentral gyrus (arrows). ger. Rate offinger tapping was 60 in 10 sec with the right index finger and 28 with the left fin- Sequence test. Kimura's (1977) manual sequence box was used. The patient was seated in front of the box and was instructed both verbally and by demonstration first to press the button with the index finger, then to pull the vertical bar with all four fingers and finally to press the bottom horizontal bar with her thumb. A trial consisted of one sequence of the above three movements under vision. The time needed to carry out five successive correct trials was measured and found to be 9 sec with the right hand and 25 sec with the left hand. Simple reaction time. Mean reaction time in response to a visual stimulus was 378 ± 53 msec with the left hand and 260 ± 32 msec with the right hand. 476 N. Motomura and Others Sensory Status of the Left Hand Somatic sensation to touch, pain, temperature, passive movement and vibration was normal. Also, the static postures of the left finge's were correctly perceived and could be reproduced by the equivalent right finger. However, she could not feel the sense of the motion of her own fingers when she herself voluntarily moved them. There was no extinction on double simultaneous stimulation. Two point discrimination was impaired on the left hand, the threshold being 20 mm for the left index finger and 4 mm for the right, 30 mm for the left palm and 10 mm for the right. There was no difference with the forearms. In a point localization test, there was a tendency to mislocate a stimulus placed on the third and fifth left fingers to the fourth left finger. Stimuli placed on the thumb and index finger were correctly located. Weight estimation was tested using weights of 5, IO, 15 and 20g. She could detect a difference of 5g easily, ipsilaterally as well as bilaterally. Stereognosis was severely impaired. When an object was placed in her left hand for identification, she would keep it still without any attempt at.manipulation. She complained to have no idea at all what it was like and had only a vague sensation that she was holding something. None of the IO objects could be identified. Perception for texture was tested for wool, silk and vinyl. They were not distinguished. Likewise, the difference between two sandpapers with different roughness could not be detected. On the contrary, graphesthesia for numbers was surprisingly well preserved. She could identify correctly all IO digits written on the palm of the left hand. She also easily identified the direction of a line drawn on the palm. Neuroradio/ogica/ Examination The results of a right cerebral angiogram was within normal range. An X-ray CT scan, which was conducted on October 28, 1989, showed a strip-like high density lesion in the right central area (Figure 1). On magnetic resonance imaging, which was performed on November 19, 1987, a low signal intensity area was found in the postcentral gyms in Tl and T2 images (Figure 2, 3). The diagnosis of the present case was hemorrhagic infarction but venous angioma is a plausible alternative. DISCUSSION In the present case motor difficulty was most marked when the patient had to manipulate an object. Motility and strength of the individual fingers, simple dynamic coordination and gross orientation in the use of an object were preserved. Sensory capacity, such as touch, pain, temperature, vibration, passive movement and graphesthesia was preserved. However, sense of active movement, point localization, two point localization, texture evaluation and stereognosis were impaired. The symptoms are similar to those of the case reported by Yamadori (1982). Yet, the type of lesion in Yamadori's case was unclear. Such symptoms with a confirmed lesion in the postcentral cortex as in the present case have never been reported. In animal experimentation, a close relationship between somesthesis and movement has been observed. Some investigators have noted motor disturbances in monkeys following postcentral lesions: loss of ability to discriminate object shapes by active palpation (Cole and Glees, 1953), slowness in the initiation and execution of movements (Peel, 1944), loathness to move and awkwardness in the posture (Kruger, 1958). Hikosaka et al., (1985) recently reported that the destruction of area 2 in an alert monkey led to the loss of finger coordination, hampering the ability to pick up a small piece of food from a small hole or funnel. This finding suggests that the postcentral gyms, especially area 2, is crucial in the control of fine finger movements and the manipulation of objects and supports the hypothesis that in our patient finger clumsiness in the manipulation of objects was secondary to the destruction of the postcentral gyms. Active touch, motor clumsiness 477 Yamadori (1982) emphasized that active touch underlies these symptoms. Gibson (1962) divided 'touch' into touching (active touch) and being touched (passive touch). He stressed that active touch is not a simple combination of touch and kinesthesis but involved a higher order receptive system, excited during activity. Norsell (1980) stated that active touch starts with an intentional motor act and then proceeds by means of exploratory movements that are shaped and reshaped successively according to the information being collected. In the present case, the patient lost the active sense of moving the fingers although the sense of passive movement was retained. Without the subtle sense of active movement, the recognition of tactile stimuli may be difficult. This sense of 'active movement' probably represents 'reafferent information' as speculated by von Holst and Mittelstaedt (1950). ABSTRACT A peculiar type of sensori-motor disturbance consequent to a lesion in the contralateral postcentral gyms was reported. The symptom was characterized by motor clumsiness of the left hand without loss of strength and with preserved finger movements on visual imitation. Motor difficulty was most marked when the patient had to manipulate an object. The analysis of the patient's behavior and of his sensory deficits suggests that the basis of the clumsiness was a deficit in active touch perception. Acknowledgment. The authors wish to thank Ms Amanda Austin fer language assistance. REFERENCES COLE, J., and GLEES, P. Effects of small lesions in sensory cortex in trained monkeys. Journal of Neurophysiology, 17: 1-13, 1953. GIBSON, J.J. Observations on active touch. Psychological Review, 69: 477-491, 1962. HIKOSAKA, 0., TANAKA, M., SAKAMOTO, M., and IWAMURA, Y. Deficits in manipulative behaviors induced by local injections of muscimol in the first somatosensory cortex of the conscious monkey. Brain Research, 325: 375-380, 1985. HOLST, von E., and MITTELSTAEDT, H. Das Reafferenzprinzip. 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Naoyasu Motomura, M.D., Department of Neuropsychiatry, Osaka Medical College, 2-7, Daigakumachi, Takatsuki, Osaka, Japan.