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William S. Gibson, Aaron E. Rusheen, Yoonbae Oh, Myung-Ho In, Krzysztof R. Gorny, Joel P. Felmlee, Bryan T. Klassen, Sung Jun Jung, Hoon-Ki Min, Kendall H. Lee, and Hang Joon Jo

OBJECTIVE

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an established neurosurgical treatment for the motor symptoms of Parkinson’s disease (PD). While often highly effective, DBS does not always yield optimal therapeutic outcomes, and stimulation-induced adverse effects, including paresthesia, muscle contractions, and nausea/lightheadedness, commonly occur and can limit the efficacy of stimulation. Currently, objective metrics do not exist for monitoring neural changes associated with stimulation-induced therapeutic and adverse effects.

METHODS

In the present study, the authors combined intraoperative functional MRI (fMRI) with STN DBS in 20 patients with PD to test the hypothesis that stimulation-induced blood oxygen level–dependent signals contained predictive information concerning the therapeutic and adverse effects of stimulation.

RESULTS

As expected, DBS resulted in blood oxygen level–dependent activation in myriad motor regions, including the primary motor cortex, caudate, putamen, thalamus, midbrain, and cerebellum. Across the patients, DBS-induced improvements in contralateral Unified Parkinson’s Disease Rating Scale tremor subscores correlated with activation of thalamic, brainstem, and cerebellar regions. In addition, improvements in rigidity and bradykinesia subscores correlated with activation of the primary motor cortex. Finally, activation of specific sensorimotor-related subregions correlated with the presence of DBS-induced adverse effects, including paresthesia and nausea (cerebellar cortex, sensorimotor cortex) and unwanted muscle contractions (caudate and putamen).

CONCLUSIONS

These results suggest that DBS-induced activation patterns revealed by fMRI contain predictive information with respect to the therapeutic and adverse effects of DBS. The use of fMRI in combination with DBS therefore may hold translational potential to guide and improve clinical stimulator optimization in patients.

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Seong-Rim Kim, Seung-Hoon You, Won-Ki Yoon, Young-Woo Kim, Sang-Don Kim, Ik-Seong Park, and Min-Woo Baik

The authors report a case of in-stent restenosis (ISR) of the middle cerebral artery (MCA) following bare-metal stent (BMS) deployment and subsequent treatment using a drug-eluting stent (DES). This 65-year-old woman presented with frequent transient ischemic attacks. Initial studies revealed occlusion of the left internal carotid artery and severe stenosis of the right MCA with decreased cerebral perfusion in the bilateral MCA territories. Stent-assisted angioplasty of the right MCA was performed using a BMS, and satisfactory results were obtained with no complications. Six months after the procedure the patient presented with recurrent symptoms, and workups revealed ISR with decreased cerebral perfusion. A DES was successfully placed without complications. Follow-up studies at 3 and 8 months after retreatment showed sustained luminal integrity and cerebral perfusion. A combination of CT angiography and perfusion CT exhibited the anatomical results and hemodynamic status of the stenotic lesion, and these findings coincided with the patient's clinical symptoms and the results of conventional cerebral angiography.

In-stent restenosis of the MCA after placement of a BMS can be treated using a DES. A combination of CT angiography and perfusion CT can be an alternative to conventional angiography. Low-profile devices with an amelioration of trackability are essential for the further incorporation of the DES into the field of endovascular neurosurgery. More clinical experiences and long-term follow-ups are mandatory to evaluate the safety, efficacy, and durability of the DES.

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Jung Won Choi, Sung Min Son, Inhee Mook-Jung, Youn Joo Moon, Ji Yeoun Lee, Kyu-Chang Wang, Hyun-Seung Kang, Ji Hoon Phi, Seung Ah Choi, Sangjoon Chong, Jayoung Byun, and Seung-Ki Kim

OBJECTIVE

Moyamoya disease (MMD) is a unique cerebrovascular disorder characterized by the progressive occlusion of the bilateral internal carotid arteries. Endothelial colony-forming cells (ECFCs), previously termed “endothelial progenitor cells,” play an important role in the pathogenesis of MMD. In this study, the authors performed morphological and functional studies of the mitochondria of ECFCs from patients with MMD to present new insights into the pathogenesis of the disease.

METHODS

The morphology of ECFCs from 5 MMD patients and 5 healthy controls was examined under both a transmission electron microscope and a confocal laser scanning microscope. The oxygen consumption rates (OCRs), mitochondrial membrane potentials (MMPs), intracellular Ca2+ concentrations, mitochondrial enzyme activities, and reactive oxygen species (ROS) levels were measured. Functional activity of the ECFCs was evaluated using a capillary tube formation assay.

RESULTS

The ECFCs from the MMD patients displayed a disrupted mitochondrial morphology, including a shorter and more circular shape. The ECFC mitochondria from the MMD patients exhibited functional abnormalities, which were assessed as a decreased OCR and an increased intracellular Ca2+ concentration. Moreover, the ECFCs from MMD patients showed increased ROS levels. Interestingly, treatment with an ROS scavenger not only reversed the mitochondrial abnormalities but also restored the angiogenic activity of the ECFCs from the MMD patients.

CONCLUSIONS

The mitochondria of ECFCs from MMD patients, as compared with those from healthy patients, exhibited morphological and functional abnormalities. This finding suggests that the mitochondrial abnormalities may have a role in the pathogenesis of MMD.

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Zang-Hee Cho, Hoon-Ki Min, Se-Hong Oh, Jae-Yong Han, Chan-Woong Park, Je-Geun Chi, Young-Bo Kim, Sun Ha Paek, Andres M. Lozano, and Kendall H. Lee

Object

A challenge associated with deep brain stimulation (DBS) in treating advanced Parkinson disease (PD) is the direct visualization of brain nuclei, which often involves indirect approximations of stereotactic targets. In the present study, the authors compared T2*-weighted images obtained using 7-T MR imaging with those obtained using 1.5- and 3-T MR imaging to ascertain whether 7-T imaging enables better visualization of targets for DBS in PD.

Methods

The authors compared 1.5-, 3-, and 7-T MR images obtained in 11 healthy volunteers and 1 patient with PD.

Results

With 7-T imaging, distinct images of the brain were obtained, including the subthalamic nucleus (STN) and internal globus pallidus (GPi). Compared with the 1.5- and 3-T MR images of the STN and GPi, the 7-T MR images showed marked improvements in spatial resolution, tissue contrast, and signal-to-noise ratio.

Conclusions

Data in this study reveal the superiority of 7-T MR imaging for visualizing structures targeted for DBS in the management of PD. This finding suggests that by enabling the direct visualization of neural structures of interest, 7-T MR imaging could be a valuable aid in neurosurgical procedures.