Impairment of bimanual in-phase movement during recovery from frontal lobe tumor surgery: a case report.

The mechanisms underlying bimanual coordination have not yet been fully elucidated. Here, we evaluated the clinical features of bimanual movement impairment in a patient following surgery for a frontal lobe tumor. The patient was an 80-year-old man who had undergone subtotal tumor resection for a tumor in the right superior frontal gyrus. Histological examination of the resected specimen led to the diagnosis of malignant lymphoma of the diffuse large B-cell type, and the patient subsequently received high-dose methotrexate-based chemotherapy. Postoperatively, the patient had difficulty with bimanual movement, and on the 5th postoperative day we found that the impairment could not be attributed to weakness. Temporal changes in the characteristics of manual movements were analyzed. Bimanual diadochokinesis (opening/closing of the hands, pronation/supination of the forearms, and sequential finger movements) was more disturbed than unilateral movements; in-phase movements were more severely impaired than anti-phase movements. Bimanual movement performance was better when cued using an auditory metronome. On the 15th postoperative day, movements improved. The present observations show that in addition to the disturbance of anti-phase bimanual movements, resection of the frontal lobe involving the supplementary motor area (SMA) and premotor cortex (PMC) can cause transient impairment of in-phase bimanual diadochokinesis, which can be more severe than the impairment of anti-phase movements. The effect of auditory cueing on bimanual skills may be useful in the diagnosis of anatomical localization of the superior frontal gyrus and functional localization of the SMA and PMC and in rehabilitation of patients with brain tumors, as in the case of degenerative movement disorders.

Intraoperative cone-beam CT with metal artifact reduction for assessment of the electrode position and the intracranial structures during deep brain stimulation procedure.

BACKGROUND: In deep brain stimulation (DBS) for Parkinson's disease (PD), the clinical outcome largely depends on the appropriate position of the electrode implanted in the targeted structure. In intraoperative cone-beam computed tomography (CT) performed for the evaluation of the electrode position, the metal artifact induced by the implanted electrode can prevent the precise localization of the electrode. Metal artifact reduction (MAR) techniques have been recently developed that can dramatically improve the visualization of objects by reducing metal artifacts after performing cone-beam CT. Hence, in this case series, we attempted to clarify the usefulness and accuracy of intraoperative cone-beam CT with MAR (intraCBCTwM) by comparing with both intraoperative cone-beam CT without MAR (intraCBCTwoM) and conventional postoperative CT (post-CT) for the assessment of the implanted electrode position and the intracranial structures during DBS procedures. METHODS: Between November 2019 and December 2020, 10 patients with PD who underwent DBS at our institution were recruited, and the images of 9 patients (bilateral: n = 8, unilateral: n = 1) were analyzed. The artifact index (AI) in intraCBCTwM or intraCBCTwoM, and conventional post-CT were retrospectively assessed using the standard deviation of the region-of-interest around the implanted electrodes and background noise. Additionally, the Euclidean distances gap of electrode tip based on post-CT in each fusion image was compared between intraCBCTwM and intraCBCTwoM. RESULTS: The AI was significantly lower in intraCBCTwM than in intraCBCTwoM (P < 0.01). The mean Euclidean distance between the tip of the electrode in intraCBCTwM and in post-CT was significantly shorter compared to that in intraCBCTwoM (P < 0.05). CONCLUSIONS: The results reported here suggest that intraCBCTwM is a more useful and accurate method than intraCBCTwoM to assess the implanted electrode position and intracranial structures during DBS.

Long-Term Volume Reduction Effects of Endovascular Embolization for Intracranial Meningioma: Preliminary Experience of 5 Cases.

BACKGROUND: Preoperative endovascular embolization of intracranial meningiomas denatures the tumor tissue, reduces intraoperative blood loss, and facilitates surgical removal. However, as most meningiomas are surgically removed within a few days after embolization, the effect of long-term volume reduction of the tumor due to the endovascular embolization remains unknown. METHODS: Five patients with intracranial meningioma underwent endovascular embolization between January 2006 and December 2014 and were followed without surgical resection for >14 days. The reduction in tumor and peritumoral edema volumes on sequential head magnetic resonance imaging, along with the clinical symptoms, were retrospectively reviewed. RESULTS: All the tumors indicated a 10%-30% volume reduction 30 days after embolization, which continued thereafter; no meningioma regrowth was observed for >90 days in 2 of 5 cases. Moreover, the peritumoral edema volume was reduced by 30%-70% at 30 days after embolization, and no subsequent increase was observed for >60 days in 4 of 5 cases. The neurologic symptoms related to the tumor mass effect improved after embolization. CONCLUSIONS: Endovascular embolization of intracranial meningiomas with n-butyl cyanoacrylate reduced the tumor and peritumoral edema volumes by 10%-30% and 30%-70%, respectively, within 30 days. Volume and edema reduction effect of embolization may last longer than expected, beyond the timing when most meningiomas are resected after embolization. In this study, we described our preliminary results of the volume reduction of intracranial meningiomas that were embolized using n-butyl cyanoacrylate and monitored without any surgical resection for >14 days. We believe that our study makes a significant contribution to the literature because we showed that volume and edema reduction effect of embolization may last longer than expected, beyond the timing when most meningiomas are resected after embolization.

Torcular dural arteriovenous fistula treated via stent placement and angioplasty in the affected straight and transverse sinuses: case report.

The successful obliteration of torcular dural arteriovenous fistula (DAVF) with a diffuse shunt in the affected sinus may require complex treatment strategies. Therapeutic goals include the preservation of normal venous drainage and complete obliteration of shunt flow. The authors report the case of a torcular DAVF. The treatment of this type of AVF may require a combined approach with transarterial and transvenous embolization, open surgery, or radiosurgery and is associated with many problems. Stent placement and angioplasty in the affected sinus result in compression of the fistulous dural wall of the sinus and decrease shunt flow. In cases in which there is a diffuse shunt in the affected sinus and no evident shunt point, such as in AVFs involving venous pouches and parasinuses, sealing the fistula orifice with self-expandable stents and angioplasty (balloon inflation) is considered the best treatment option to preserve normal cerebral venous sinus drainage and obliterate shunt flow. In such cases, the authors recommend using one or more self-expandable and closed-cell stents and using angioplasty to avoid endoleakage into the gap between the stent graft and the vessel wall.