Supplementary+Motor+Area

The supplementary motor area (SMA) is located along the medial walls of the hemispheres.

-General guiding and coordinating the large, gross movements of the extremities through space -Movement preparation -Directing movement toward or away from specific stimuli -Active during the modification, learning and establishment of new movement programs -May act to make decisions regarding possible movements based on these signals well before a movement is initiated.
 * Primary Functions:**

6
 * Broadman's Areas:**

-Premotor Cortex -Primary Motor Area -Parietal Lobe
 * Connected From:**

-Striatum -Anterior cingulate -Amygdala -Motor thalamus -Corticospinal tract -Brainstem -Cerebellum -Spinal cord
 * Connected To:**

**Electrical Stimulation: ** -Complex semipurposeful movements (not fine motor movements however) <span style="font-family: 'Times New Roman',serif;">-Vocalization <span style="font-family: 'Times New Roman',serif;">-Postural synergies involving the trunk and extremities bilaterally

<span style="font-family: 'Times New Roman',serif;">-Body may become stiff <span style="font-family: 'Times New Roman',serif;">-Movements tend to be slow and incoordinated <span style="font-family: 'Times New Roman',serif;">-Clumsiness <span style="font-family: 'Times New Roman',serif;">-Severe agraphia <span style="font-family: 'Times New Roman',serif;">-Impairments of bimanual coordination and difficulty performing rapid or alternating movements <span style="font-family: 'Times New Roman',serif;">-May walk with short steps and suffer disturbances involving posture, balance, and gait.
 * Injury/Damage:**

Severe Injury: <span style="font-family: 'Times New Roman',serif;">-May become mute <span style="font-family: 'Times New Roman',serif;">-May become so stiff and unmoving that they appear to demonstrate all the classic signs of catatonia including gegenhalten and waxy flexibility.

<span style="font-family: 'Times New Roman',serif; font-size: medium;">becomes bilaterally activated during movements of the right or left half of the body.
 * Notes:**

<span style="color: #000000; font-family: 'Times New Roman',serif;">In fact, single cell recordings and studies of blood flow studies and movement related evoked potentials indicate increased activity in this area when simply imagining as well as when performing complex movements of the fingers and hands.

<span style="color: #000000; font-family: 'Times New Roman',serif;">In general, however, and as based on single cell recording (vs functional imaging) activity begins in the SMA well before movements are initiated and prior to activation within the premotor and primary motor areas. For example, when anticipating or preparing to make a movement, but prior to the actual movement, neuronal activity will first begin and then dramatically increase in the SMA, followed by activity in the premotor and then the primary motor area, and then the caudate and last of all the putamen and globus pallidus. <span style="font-family: 'Times New Roman',serif;">Presumably the putamen, in conjunction with the caudate, transmits this information to the globus pallidus which in turn projects to the motor thalamus, brainstem reticular formation, as well as to the motor neocortex, thus creating a very elaborate feedback loop which is also influenced by the anterior cingulate and amygdala.