Supplementary Motor Complex and Disturbed Motor Control – a Retrospective Clinical and Lesion Analysis of Patients after Anterior Cerebral Artery Stroke

Abstract

BackgroundBoth the supplementary motor complex (SMC), consisting of the supplementary motor area (SMA) proper, the pre-SMA, and the supplementary eye field, and the rostral cingulate cortex are supplied by the anterior cerebral artery (ACA) and are involved in higher motor control. The Bereitschaftspotential (BP) originates from the SMC and reflects cognitive preparation processes before volitional movements. ACA strokes may lead to impaired motor control in the absence of limb weakness and evoke an alien hand syndrome (AHS) in its extreme form.AimTo characterize the clinical spectrum of disturbed motor control after ACA strokes, including signs attributable to AHS and to identify the underlying neuroanatomical correlates.MethodsA clinical assessment focusing on signs of disturbed motor control including intermanual conflict (i.e., bilateral hand movements directed at opposite purposes), lack of self-initiated movements, exaggerated grasping, motor perseverations, mirror movements, and gait apraxia was performed. Symptoms were grouped into (A) AHS-specific and (B) non-AHS-specific signs of upper limbs, and (C) gait apraxia. Lesion summation mapping was applied to the patients’ MRI or CT scans to reveal associated lesion patterns. The BP was recorded in two patients.ResultsTen patients with ACA strokes (nine unilateral, one bilateral; mean age: 74.2 years; median NIH-SS at admission: 13.0) were included in this case series. In the acute stage, all cases had marked difficulties to perform volitional hand movements, while movements in response to external stimuli were preserved. In the chronic stage (median follow-up: 83.5 days) initiation of voluntary movements improved, although all patients showed persistent signs of disturbed motor control. Impaired motor control is predominantly associated with damaged voxels within the SMC and the anterior and medial cingulate cortex, while lesions within the pre-SMA are specifically related to AHS. No BP was detected over the damaged hemisphere.ConclusionACA strokes involving the premotor cortices, particularly the pre-SMA, are associated with AHS-specific signs. In the acute phase, motor behavior is characterized by the inability to carry out self-initiated movements. Motor control deficits may persist to a variable degree beyond the acute phase. Alterations of the BP point to an underlying SMC dysfunction in AHS.

Frequency‐specific alterations of regional homogeneity in subcortical stroke patients with different outcomes in hand function

“…In an interhemispheric FC study, stroke patients displayed decreased interhemispheric interaction in the CPL compared with that of HCs, and there was a significant positive correlation between the interhemispheric FC in the CPL and the FMA scores of the stroke patients (Tang et al, ). Therefore, the findings of abnormal activation in the SMA and CPL in the typical band indicated that the impairment in the cerebellar–cerebral information circuit may contribute to reduced hand function (O'Reilly, Beckmann, Tomassini, Ramnani, & Johansen‐Berg, ), and the poor hand function outcomes in CPH patients may be associated with dysfunctional motor control (Amengual et al, ; Brugger, Galovic, Weder, & Kägi, ).…”

“…In addition, the ReHo values in the bilateral CPL were positively correlated with FMA-HW scores, and that in the contralesional SMA was negatively correlated with FMA-HW scores. Therefore, the findings of abnormal activation in the SMA and CPL in the typical band indicated that the impairment in the cerebellar-cerebral information circuit may contribute to reduced hand function (O'Reilly, Beckmann, Tomassini, Ramnani, & Johansen-Berg, 2010), and the poor hand function outcomes in CPH patients may be associated with dysfunctional motor control (Amengual et al, 2014;Brugger, Galovic, Weder, & Kägi, 2015). Patients with motor conversion disorder showed abnormal activity in the SMA during motor preparation compared to that of normal volunteers (Voon, Brezing, Gallea, & Hallett, 2011).…”

Graded fMRI Neurofeedback Training of Motor Imagery in Middle Cerebral Artery Stroke Patients: A Preregistered Proof-of-Concept Study

“…The study's aim was mainly to test for the feasibility of graded fMRI neurofeedback training of the SMA in first time MCA stroke patients. The SMA is an attractive target region of interest (ROI) in MCA stroke patients because it is supplied by the anterior cerebral artery (Brugger et al, 2015 ) and thus is not expected to have (substantially) compromised hemodynamic function following MCA stroke. Our first hypothesis was that patients could activate the SMA through motor imagery.…”

Facilitatory rTMS over the Supplementary Motor Cortex Impedes Gait Performance in Parkinson Patients with Freezing of Gait

“…The SMC is assumed to keep the balance between motor initiation and motor suppression [ 9 ]. Its relevance for gait control is underpinned by the occurrence of FOG-like gait patterns in patients with SMC lesions [ 10 , 11 ]. It is not surprising that the SMC is considered to play a central role in PD and, in particular, in PD-related gait impairment.…”