Regional cerebral blood flow during voluntary arm and hand movements in human subjects

Abstract

1. Regional cerebral blood flow (rCBF) was measured using positron emission tomography in six normal volunteers while at rest and while performing four different repetitive movements of the right arm. 2. The four movements were performed in random order and consisted of abduction of the index finger, making a fist, sequential thumb to digit opposition, and shoulder flexion. All the movements were done at the same rate, using an auditory cue and involved displacements through similar amounts of the physiological range at each joint. 3. Increases in rCBF were interpreted as evidence of local neural activation and all four movements were associated with significant increases in CBF in the contralateral sensorimotor and premotor areas and in the supplementary motor area (SMA). 4. The average increase in blood flow in the contralateral sensorimotor cortex was significantly greater for the shoulder movement (31%) than for the three other movements. The increases with finger opposition (21%) and fist-making (24%) were not significantly different, and both were significantly greater than with index finger movement (13%). These data indicate that neither "fractionation" nor distal movement per se cause selective activation of sensorimotor cortex. 5. Significantly greater increases in blood flow in both the contralateral premotor cortex and the SMA ("nonprimary motor areas") occurred with shoulder movement than with the other movements. Because this difference may be related to the significantly greater activation occurring concurrently in the sensorimotor cortex, this finding does not prove unequivocally a "selective" role of the nonprimary motor areas in proximal movement. 6. Neither of the two nonprimary motor areas showed selective activation when a simple sequence of finger movements was performed compared with repetitive contractions of the same fingers. 7. Shoulder movement alone was associated with significant increases in rCBF in the ipsilateral sensorimotor cortex (10%), the superior vermis of the cerebellum (19%), and Brodmann areas 5 and 40 in the contralateral hemisphere. 8. The average location of the center of excitation in the sensorimotor cortex and SMA differed for the four movements and was interpreted as evidence of within-limb somatotopy. The shoulder focus lay highest in the sensorimotor cortex and lowest in the SMA.

Quantification of Network Perfusion in ASL Cerebral Blood Flow Data with Seed Based and ICA Approaches

“…Moreover, in the present study we also attempted to quantify network activity by means of absolute CBF. The absolute CBF values extracted for both networks and during rest or task condition, as well as the percentage increase were in agreement with values reported in literature ( (Wang et al 2003b) ASL/ (Colebatch et al 1991) PET). The ANOVA results of the CBF values further demonstrated the stability and thus test-retest reliability of the presented approach.…”

A PET activation study of dynamic mechanical allodynia in patients with mononeuropathy

“…However, occasional muscular activity was observed in all but one of the patients during the scanning period. Separating movement related activations from pain related activations is a potential problem in all functional imaging studies of pain since any observed movement or unobserved muscle tension may activate the postcentral gyrus in concert with the motor cortex (Colebatch et al, 1991;Hsieh et al, 1995b). In addition, movement intention/preparation may increase the activity in the motor cortex (Hsieh et al, 1994;Deiber et al, 1996).…”

Electric and magnetic fields of the brain accompanying internal simulation of movement

“…(3) Lesion studies in monkeys and observations in humans with brain lesions indicate that MI is critical in the performance of discrete movements of fingers and other parts of the body (review in [24]). PET studies have shown that MI is activated as much by whole hand movements as by the independent movement of the fingers [5]. Simultaneous movements of two fingers causes even less activation of MI than sequential movements of these fingers with the frequency of movements being kept constant [29].…”