Localization in somatic sensory and motor areas of human cerebral cortex as determined by direct recording of evoked potentials and electrical stimulation

Abstract

This paper reports and illustrates in figurine style results obtained by electrical stimulation of the cortex in 20 patients and by recording of cortical evoked potentials (EPs) in 13 of these patients, whose surgery required wide exposure of the Rolandic or paracentral regions of the cortex. This study is unique in that cutaneous receptive fields related to specific cortical sites were defined by mechanical stimulation, as is done in animals, in contrast to electrical stimulation of peripheral nerves at fixed sites, as in scalp EP recordings. Observations were made on pre- and postcentral gyri, on the second somatic sensory-motor area, on the supplementary motor area, and on the supplementary sensory area. In two patients with phantom limb pain, the pain was elicited in one on stimulation of the postcentral arm area, and in the other on stimulation of the supplementary sensory leg area. Surgical removal of these areas had the immediate effect of abolishing the phantoms and the pain. Long-term follow-up review was not possible. In one patient with severe Parkinson's disease, stimulating currents subthreshold for the elicitation of movement resulted in disappearance of tremor and rigidity for short periods after stimulation of the precentral gyrus. The possible patterns of organization of the human pre- and postcentral areas are considered and compared with those of the chimpanzee and other primates. In patients in whom data from pre- and postcentral gyri were adequate, it appeared that the precentral face-arm boundary is situated 1 to 2 cm higher than the corresponding postcentral boundary.

Characterization of some morphological parameters of orbicularis oculi motor neurons in the monkey

“…This relationship is supported by studies examining the effects of cortical stimulation on the ventral region of M1 which primarily elicits contralateral lower facial movements (Penfield, 1937;Woolsey et al,1952;Woolsey et al, 1979;McGuinness et al, 1980;Huang et al, 1988;Triggs et al, 2005) and longstanding clinical observations which have drawn the association between prominent contralateral lower facial paresis and injury afflicting the lateral peri-central cortex of the cerebral hemisphere (Green, 1938;Symon et al, 1975;Brodal, 1981;Adams et al, 1997). However, it has also been shown that to a lesser extent, OO activation can occur following direct stimulation of M1 (Woolsey et al, 1979;Benecke et al, 1988;Cruccu et al, 1990;Roedel et al, 2001;Sohn et al, 2004;Paradiso et al, 2005) and deficits transpire in OO function following damage to M1 that are less notable than perioral deficits, but are nonetheless detectable (Kojima et al, 1997). Collectively this observation may contribute to the complex nature of facial expression and possibly add to the inherent difficulties in isolating distinct, individuated facial muscle contractions following cortical stimulation (Woolsey et al, 1952;Strick and Preston, 1979;McGuinness et al, 1980;Brecht et al, 2004;Schieber, 2004).…”

Regional brain activation in conscious, nonrestrained rats in response to noxious visceral stimulation

“…The increased activation in motor cortex in response to CRD was unlikely due to locomotion as activity counts were extremely low during the period of distention, and without significant group differences. Neuroimaging studies in humans have associated abdominal contractions with activation of the superolateral precentral gyrus (lateral portion of motor cortex) and premotor and supplemental motor cortex [10,72]. In addition, focal stimulation of these areas, either magnetically or electrically, evokes abdominal straining [15,20,34].…”

Three-dimensional locations and boundaries of motor and premotor cortices as defined by functional brain imaging: A meta-analysis

“…The ventral limit of M1 has been reported as being situated just above the Sylvian Fissure (Woolsey et al, 1979;Corfield et al, 1999), or varying as much as 4cm dorsally (Brodmann, 1909;Urasaki et al, 1994;Geyer et al, 2000b). Similarly, the ventral limit of S1 has been shown to correspond to the same dorso-ventral position as M1, immediately caudal to M1 at the base of the postcentral gyrus (Boling et al, 2002).…”