Assessment of the praxis circuit in glioma surgery to reduce the incidence of postoperative and long-term apraxia: a new intraoperative test

Abstract

OBJECTIVE Apraxia is a cognitive-motor deficit affecting the execution of skilled movements, termed praxis gestures, in the absence of primary sensory or motor disorders. In patients affected by stroke, apraxia is associated with lesions of the lateral parietofrontal stream, connecting the posterior parietal areas with the ventrolateral premotor area and subserving sensory-motor integration for the hand movements. In the neurosurgical literature to date, there are few reports regarding the incidence of apraxia after glioma surgery. A retrospective analysis of patients who harbored a glioma around the central sulcus and close to the parietofrontal circuits in depth showed a high incidence of long-term postoperative hand apraxia, impairing the patients' quality of life. To avoid the occurrence of postoperative apraxia, the authors sought to develop an innovative intraoperative hand manipulation task (HMt) that can be used in association with the brain mapping technique to identify and preserve the cortical and subcortical structures belonging to the praxis network. METHODS The intraoperative efficacy of the HMt was investigated by comparing the incidence of postoperative ideomotor apraxia between patients undergoing mapping with (n = 79) and without (n = 41) the HMt. Patient groups were balanced for all demographic and clinical features. RESULTS In patients with lesions in the dominant hemisphere, the HMt dramatically reduced the incidence of apraxia, with a higher sensitivity for the ideomotor than for the constructional abilities; patients with lesions in the nondominant hemisphere benefitted from the HMt for both ideomotor and constructional abilities. The administration of the test did not reduce the extent of resection. CONCLUSIONS The HMt is a safe and feasible intraoperative tool that allowed surgeons to prevent the occurrence of long-term hand apraxia while attaining resection goals for the surgical treatment of glioma.

Direct electrical stimulation of the premotor cortex shuts down awareness of voluntary actions

“…As reported in a previous study using the same motor task, DES on PMC interferes with motor execution 12,14,15 . Does the disruption of PMC simultaneously interfere with the patients' motor awareness?…”

“…(1) A positive effect in altering motor execution was expected based on previous literature employing DES during the same HMt 12,14,15 . (2) A positive effect in altering the motor awareness was expected based on anatomical and functional evidence in AHP patients 2,7-9,48,49 and in healthy subjects 44,45 .…”

“…In the control condition, when the same procedure is applied to S1, we expect DES interference with motor execution (altered HMt) (ref. 12 , see also ref. 16 ) but not with motor awareness (unaltered MMt).…”

“…To this aim, 12 awake patients perform a voluntary motor task with their right hand, consisting of rhythmical manipulation of a cylindrical handle (handmanipulation task (HMt), see Fig. 1) 12 . In eight patients, the HMt is coupled with an online verbal motor-monitoring task (MMt), in which the patient have to evaluate in real time his/her motor performance, stating OK when the action is executed without experiencing any difficulty, and stating STOP when some difficulties is noticed.…”

A study of parietal-motor connectivity by intraoperative dual cortical stimulation

“…A third cluster was identified due to its localization, in the mid-portion of the intraparietal sulcus. The clinical neurosurgeon’s attention toward motor function of the parietal lobe is increasingly recognized (Rossi et al ., 2018). The present data are potentially exploitable as an IONM procedure for the monitoring of complex motor functions, though further investigations are required.…”