Post operative supplementary motor area syndrome: clinical features and outcome

Abstract

The syndrome of the supplementary motor area (SMA) is not well recognized and its features can easily be confused with pyramidal weakness. The authors describe the SMA syndrome in six patients who underwent surgery for tumours located in the SMA, three in the dominant and three in the non-dominant hemispheres. All of them underwent complete resection of the anatomically described SMA, with partial (n = 4) or total resection (n = 2) of the tumour. In the postoperative period, all these patients exhibited reduction of spontaneous movements and difficulty in performing voluntary motor acts to command in the contralateral limbs, although the tone in the limbs was maintained or increased. The function of these limbs in serial automatic motor activities (for example, dressing and walking) was, however, relatively unaffected. Speech deficits were seen in only one of three patients with the dominant SMA syndrome. Besides a severe impairment of volitional movements, the salient features of the deficits in this syndrome are hemineglect and dyspraxia or apraxia involving the contralateral limbs. All patients recovered their motor functions over varying periods of time ranging from one to a few weeks. Long-term follow-up (median 24 months) in five patients revealed complete return of function in the affected limbs. It is important to recognize the entity of the SMA syndrome and differentiate it from the deficits that result from operative damage to the motor cortex as the deficits associated with the former are likely to recover almost completely over a short period of time.

Combined Damage to the Right Hemispheric Hand Area in the Primary Motor and Sensory Area Plays a Critical Role in Motor Hemineglect

“…In contrast, the location of craniotomy for brain tumors between S1 and M1 was far lateral, thereby the plane of craniotomy was oblique, not horizontal, and therefore, brain function around such tumors could be susceptible to deterioration due to the brain shift. Indeed, decreasing intracranial pressure by removal of cerebrospinal fluid resulted in transient improvement in motor function, suggesting that compression of S1 and M1 by the brain tumor played a role in this phenomenon, which is consistent with results from prior studies [14]. In case 2, the patient also showed motor hemineglect of the left hand during awake surgery despite the fact that the tumor between S1 and M1 was relatively small.…”

Resection frequency map after awake resective surgery for non-lesional neocortical epilepsy involving eloquent areas

“…However, it is also well known that the removal of the SMA can cause transient neurological deficits, which include motor weakness or speech disturbance [2, 20, 41, 48, 51]. In the present study, eight patients underwent removal of the unilateral SMA (Table 4).…”

“…Among these patients, two patients exhibited transient neurological morbidities including coordination disturbance of hand and motor weakness of contralateral leg (cases 10 and 17 in Table 4). Several factors, including the degree of resection of the SMA, injury of the cingulate gyrus and the nature of disease, could influence the degree of the neurological deficits after the removal of the SMA [2, 42, 51]. …”

Sex Effect on Presurgical Language Mapping in Patients With a Brain Tumor

“…However, lesion and stimulation studies suggest that the SMA also plays a pivotal role in higher-order cognitive control, including control of speech perception and speech initiation (Krainik et al, 2003;Tourville and Guenther, 2011;Hertrich et al, 2016). Neurosurgical resection involving the SMA may lead to the "SMA syndrome" characterized by contralateral akinesia and mutism (Laplane et al, 1977;Bannur and Rajshekhar, 2000). The left SMA was shown to be recruited during sentence-level (Zacà et al, 2012(Zacà et al, , 2013Black et al, 2017) and word-level (Wise et al, 1991;Warburton et al, 1996;Black et al, 2017) language processing.…”