Outcome of pallidal deep brain stimulation for treating isolated orofacial dystonia.

BACKGROUND: Isolated orofacial dystonia is a rare segmental neurological disorder that affects the eye, mouth, face, and jaws. Current literature on pallidal surgery for orofacial dystonia is limited to case reports and small-scale studies. This study was to investigate clinical outcomes of deep brain stimulation (DBS) of the globus pallidus internus (GPi) in patients with isolated orofacial dystonia. METHODS: Thirty-six patients who underwent GPi DBS at Incheon St. Mary's Hospital, The Catholic University of Korea, between 2014 and 2019 were included in this study. Burke-Fahn-Marsden Dystonia Rating Scale, Unified Dystonia Rating Scale, and Global Dystonia Severity Rating Scale were retrospectively retrieved for analysis before surgery, at 6-month follow-up as short-term outcome, and at follow-up over 1 year (12 months to 69 months) as long-term results. RESULTS: Mean total BFMDRS-M scores at the three time points (baseline, 6 months, and over 1 year follow-up) were 11.6 ± 4.9, 6.1 ± 5.2 (50.3 ± 29.9% improvement, p < 0.05), and 4.3 ± 4.2 (65.0 ± 24.2% improvement, p < 0.05), respectively. In terms of UDRS and GDS, improvement rates were 45.1% (p < 0.001) and 47.7% (p < 0.001) at 6 months, and 63.8% (p < 0.001) and 65.7% (p < 0.001) at over 1 year after surgery, respectively. CONCLUSIONS: Bilateral GPi DBS in isolated orofacial dystonia can be effective if conservative treatment option fails. Its benefit is not only observed in a short term, but also maintained in a long-term follow-up.

Range of voluntary neck motility predicts outcome of pallidal DBS for cervical dystonia.

BACKGROUND: The effectiveness of pallidal deep brain stimulation (GPi DBS) for cervical dystonia has been extensively described, but controversies exist about which prognostic factor is clinically useful. We previously reported that classification of tonic- or phasic-type cervical dystonia is useful for predicting clinical prognosis; however, the approach used by physicians to distinguish between the two types remains subjective. OBJECTIVE: The aim of this study was to develop a prognostic factor of GPi DBS for cervical dystonia. METHODS: By identifying distributions of range of motion scores between phasic- and tonic-type cervical dystonia, a new prognostic factor group was developed based on whether the patients could voluntarily move their head to the opposite side against dystonic motions. The prognosis for GPi DBS in the two groups was analyzed according to the time sequence. RESULTS: Patients who were able to move their head past the midline had a better long-term prognosis after GPi DBS than did those who could not. In the early post-operative phase, there were no significant differences in the clinical outcomes between the two groups. CONCLUSION: A range of voluntary neck motility with respect to the midline is an objective factor that is useful in predicting the prognosis of patients with cervical dystonia. This result renders needs for future study addressing neuroplastic changes in the brain network caused by GPi DBS.

Different clinical course of pallidal deep brain stimulation for phasic- and tonic-type cervical dystonia.

BACKGROUND: Dystonia has been treated well using deep brain stimulation at the globus pallidus internus (GPi DBS). Dystonia can be categorized as two basic types of movement, phasic-type and tonic-type. Cervical dystonia is the most common type of focal dystonia, and sequential differences in clinical outcomes between phasic-type and tonic-type cervical dystonia have not been reported. METHODS: This study included a retrospective cohort of 30 patients with primary cervical dystonia who underwent GPi DBS. Age, disease duration, dystonia direction, movement types, employment status, relevant life events, and neuropsychological examinations were analyzed with respect to clinical outcomes following GPi DBS. RESULTS: The only significant factor affecting clinical outcomes was movement type (phasic or tonic). Sequential changes in clinical outcomes showed significant differences between phasic- and tonic-type cervical dystonia. A delayed benefit was found in both phasic- and tonic-type dystonia. CONCLUSIONS: The clinical outcome of phasic-type cervical dystonia is more favorable than that of tonic-type cervical dystonia following GPi DBS.

Electrophysiological interpretations of the clinical response to stimulation parameters of pallidal deep brain stimulation for cervical dystonia.

OBJECTIVE: Deep brain stimulation (DBS) at the posterolateral ventral portion of the globus pallidus internus (GPi) has been regarded as a good therapeutic modality. Because the theoretical principle behind the stimulation parameters is yet to be determined, this study aimed to interpret analyses of the stimulation parameters used in our department based on an electrophysiological review. METHODS: Nineteen patients with medically refractory idiopathic cervical dystonia who underwent GPi DBS were enrolled. The baseline and follow-up parameters were analyzed according to their dependence on time after DBS. The pattern of changes in the stimulation parameters over time, the differences across the four active contacts, and the relationship between the stimulation parameters and clinical benefits were evaluated. RESULTS: Mean age and disease duration were 50.9 years and 54.7 months, respectively. Mean follow-up duration was 22.6 months. The amplitude and frequency exhibited significant increasing temporal patterns, i.e., a mean amplitude and frequency of 3.1 V and 132.2 Hz at the initial setting and 4.0 V and 142.6 Hz at the last follow-up, respectively. The better clinical response group (clinical improvement rate of 65-100 %) used a narrower pulse width (mean value of 78.4 µs) than the worse clinical response group (clinical improvement rate of 5-60 %, mean of value of 88.6 µs). Active contact at the GPe was used more often in the worse clinical response group than in the better response group. CONCLUSIONS: Based on electrophysiological considerations, these patterns of stimulation parameters could be interpreted. This interpretation was based on a theoretical understanding of the mechanisms of action of DBS, i.e., that the abnormal neural signal is substituted by an induced neural signal, which is generated by therapeutic DBS.

Effectiveness of selective peripheral denervation in combination with pallidal deep brain stimulation for the treatment of cervical dystonia.

BACKGROUND: Selective peripheral denervation (SPD) and deep brain stimulation of the globus pallidus (GPi-DBS) are available surgical options for patients with medically refractory cervical dystonia (CD). There are few data available concerning whether patients who have unsatisfactory treatment effects after primary surgery benefit from a different type of subsequent surgery. The aim of this study was to assess whether combining these surgical procedures (SPD plus GPi-DBS) was effective in patients with unsatisfactory treatment effects after their initial surgery. METHODS: Forty-one patients with medically refractory idiopathic CD underwent SPD and/or GPi-DBS. Patients who were dissatisfied with their primary surgery (SPD or GPi DBS) elected to subsequently undergo a different type of surgery. These patients were assessed with the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS). RESULTS: SPD alone and GPi-DBS alone were performed in 16 and 21 patients, respectively. Four patients had unsatisfactory treatment effects after the initial surgery and subsequently underwent another type of surgery. Among them, two patients with persistent dystonia after SPD subsequently underwent GPi-DBS, and two other patients who had insufficient treatment effects following GPi-DBS were subsequently treated with SPD. All of these patients experienced sustained improvement from the combined surgical procedures according to the TWSTRS score during a long-term follow-up of 12-90 months. CONCLUSIONS: Patients with unsatisfactory treatment effects after an SPD or GPi-DBS experienced improvement from subsequently undergoing other types of surgery. Therefore, combined surgical procedures are additional surgical options with good outcomes in the treatment of patients with residual symptoms after their initial surgery.

The Clinical Effects of C2 and C3 Medial Branch Block for Medically Intractable Headache : a Retrospective Study.

Objective: This study aimed to evaluate the clinical effects of medial branch blocks (MBB) C2 and C3 in treating patients with medically intractable headaches. Methods: The medical records of 81 patients with medically intractable headaches who underwent a C2/3 MBB between January 2019 and March 2022 were retrospectively reviewed. The degrees of pain were evaluated using a visual analogue scale (VAS) score (rating 0-10) on baseline and after procedures. To evaluate patients' satisfaction for the treatment, self-reporting measurements were examined and were categorized as excellent (>90% pain relief), good (50%-90% pain relief), fair (10%-50% pain relief), and none (<10% pain relief). Results: The total number of MBB procedure was 107. The average baseline VAS score was 7.4 ±1.5, which improved significantly to 2.6 ±2.3, 3.6 ±2.6, and 4.5 ±3.2 on 1-3 days, 3-7 days, and 3 months after the procedure, respectively (Wilks' lambda within group test, P <0.001). For the subjective feeling of pain relief, percentages of "excellent" response in the self-reporting measurements were significantly decreased over time (chi-square test; P= 0.001). Conclusion: This study demonstrates clinical effectiveness of C2/3 MBB in patients with medically intractable headaches, with both early and prolonged benefits.

Hyperkinetic Rat Model Induced by Optogenetic Parafascicular Nucleus Stimulation.

OBJECTIVE: The parafascicular nucleus (PF) plays important roles in controlling the basal ganglia. It is not well known whether the PF affects the development of abnormal involuntary movements (AIMs). This study was aimed to find a role of the PF in development of AIMs using optogenetic methods in an animal model. METHODS: Fourteen rats were underwent stereotactic operation, in which they were injected with an adeno-associated virus with channelrhodopsin (AAV2-hSyn-ChR2-mCherry) to the lateral one third of the PF. Behavior test was performed with and without optical stimulation 14 days after the injection of the virus. AIM of rat was examined using AIM score. After the behavior test, rat's brain was carefully extracted and the section was examined using a fluorescence microscope to confirm transfection of the PF. RESULTS: Of the 14 rats, seven rats displayed evident involuntary abnormal movements. AIM scores were increased significantly after the stimulation compared to those at baseline. In rats with AIMs, mCherry expression was prominent in the PF, while the rats without AIM lacked with the mCherry expression. CONCLUSION: AIMs could be reversibly induced by stimulating the PF through an optogenetic method.

Neuromodulation for Trigeminal Neuralgia.

Clinical studies on neuromodulation intervention for trigeminal neuralgia have not yet shown promising results. This might be due to the fact that the pathophysiology of chronic trigeminal neuropathy is not yet fully understood. Chronic trigeminal neuropathy includes trigeminal autonomic neuropathy, painful trigeminal neuropathy, and persistent idiopathic facial pain. This disorder is caused by complex abnormalities in the pain processing system, which is comprised of the affective, emotional, and sensory components, rather than mere abnormal sensation. Therefore, integrative understanding of the pain system is necessary for appropriate neuromodulation of chronic trigeminal neuropathy. The possible neuromodulation targets that participate in complex pain processing are as follows : the ventral posterior medial nucleus, periaqueductal gray, motor cortex, nucleus accumbens, subthalamic nucleus, globus pallidus internus, anterior cingulate cortex, hypothalamus, sphenopalatine ganglion, and occipital nerve. In conclusion, neuromodulation interventions for trigeminal neuralgia is yet to be elucidated; future advancements in this area are required.

Half-Centennial History of Journal of Korean Neurosurgical Society : Midway from Domestic Journal to International Journal with Good Influence in Global Neurosurgery.

October 2022 marks the 50th anniversary of the founding of Journal of Korean Neurosurgical Society (JKNS). Staring as official journal of Korean Neurosurgical Society (KNS) in 1972, JKNS is a journal that is listed in the science citation index (SCI) and its impact factor has been steadily rising in recent years. The past history of JKNS was reviewed with a focus on important milestone, and the direction of future development is suggested.

Clinical Outcomes after Spinal Cord Stimulation According to Pain Characteristics.

OBJECTIVE: Spinal cord stimulation (SCS) is an effective treatment for chronic neuropathic pain. However, its clinical efficacy in regard to specific types of pain has not been well studied. The primary objective of this study was to retrospectively analyze the clinical outcomes of paddle-type SCS according to the type of neuropathic pain. METHODS: Seventeen patients who underwent paddle-lead SCS at our hospital were examined. Clinical outcomes were evaluated pre- and postoperatively (3 months, 1 year, and last follow-up) using the Neuropathic Pain Symptom Inventory (NPSI). The NPSI categorizes pain as superficial, deep, paroxysmal, evoked, or dysesthesia and assess the duration of the pain (pain time score). Changes in NPSI scores were compared with change in Visual analogue scale (VAS) scores. RESULTS: After SCS, the pain time score improved by 45% (independent t-test, p=0.0002) and the deep pain score improved by 58% (independent t-test, p=0.001). Improvements in the pain time score significantly correlated with improvements in the VAS score (r=0.667, p=0.003, Spearman correlation). Additionally, the morphine milligram equivalent value was markedly lower after vs. before surgery (~49 mg, pared t-test, p=0.002). No preoperative value was associated with clinical outcome. CONCLUSION: The NPSI is a useful tool for evaluating the therapeutic effects of SCS. Chronic use of a paddle-type spinal cord stimulation improved the deep pain and the pain time scores.

The Evolution of Journal of Korean Neurosurgical Society from 2017 to 2020 : The Beginning of a Great Development.

Every researcher wants their research to gain more recognition, and this desire is achieved by publishing their article in a journal with higher impact. It is very important to get researchers interested in the Journal of Korean Neurosurgical Society (JKNS). Therefore, the first goal was to promote the publication of papers in our journal. To do this, a table of contents was sent out, and the citation ranking was announced every 2 months. Several efforts have been made to publish good papers. Foreign speakers, who were invited to a conference hosted by the Korean Neurosurgical Society were contacted and politely requested to write a paper addressing their recent research. Domestic and international researchers highly renowned in their fields were also contacted to submit their novel works to our journal. The journal impact factor of our journal has continued to rise for the last 3 years and reached 1.376 in 2019. It can be said that the JKNS is now competitive with other international neurosurgery journals. These achievements were not due to the efforts of the editorial boards alone. This was because our society members have submitted very good papers, and because many of our members have cited the papers published in our journal. We believe that this will continue in the future. The next step of evolution of the JKNS has begun, and this is the beginning of another great development.

Comparison of treatment results between selective peripheral denervation and deep brain stimulation in patients with cervical dystonia.

BACKGROUND/AIMS: Cervical dystonia (CD) is the most common form of focal dystonia. The treatment options for CD include medical therapy and surgery. The 3 basic types of CD are tonic, phasic and tremulous. Selective peripheral denervation (SPD) and globus pallidus internus (GPi) deep brain stimulation (DBS) have been developed as therapeutic options for the treatment of CD. METHODS: Between 1997 and 2009, 24 patients with CD underwent operations: either SPD (n = 16) or DBS (n = 8). The mean follow-up period was 29.5 months (range = 2-59). The mean age at onset of symptoms was 46.6 years (range = 27-65). The patients were evaluated with the subjective scores and the Toronto Western Spasmodic Torticollis Scale scores. RESULTS: All patients showed gradual improvement after SPD and DBS. No statistically significant differences were seen between the SPD group and the DBS group. However, there was a trend toward greater pain reduction in the DBS group (p = 0.094). CONCLUSION: Both the SPD group and the DBS group showed successful improvement in their Toronto Western Spasmodic Torticollis Scale scores as well as subjective scores. The GPi DBS group showed a remarkable improvement on the pain scale and there was a trend toward greater pain reduction in the DBS group.

Surgical Reconstruction Using a Flanged Mesh Cage without Plating for Cervical Spondylotic Myelopathy and a Symptomatic Ossified Posterior Longitudinal Ligament.

OBJECTIVE: We introduce innovative method of cervical column reconstruction and performed the reconstruction with a flanged titanium mesh cage (TMC) instead of a plate after anterior corpectomy for cervical spondylotic myelopathy (CSM) and an ossified posterior longitudinal ligament (OPLL). METHODS: Fifty patients with CSM or OPLL who underwent anterior cervical reconstruction with a flanged TMC were investigated retrospectively. Odom's criteria were used to assess the clinical outcomes. The radiographic evaluation included TMC subsidence, fusion status, and interbody height. Thirty-eight patients underwent single-level and 12 patients underwent two-level corpectomy with a mean follow-up period of 16.8 months. RESULTS: In all, 19 patients (38%) had excellent outcomes and 25 patients (50%) had good outcomes. Two patients (4%) in whom C5 palsy occurred were categorized as poor. The fusion rate at the last follow-up was 98%, and the severe subsidence rate was 34%. No differences in subsidence were observed among Odom's criteria or between the single-level and two-level corpectomy groups. CONCLUSION: The satisfactory outcomes in this study indicate that the flanged TMC is an effective graft for cervical reconstruction.

Neuropsychological consequences of pallidal deep brain stimulation altering brain networks.

The purpose of this study was to evaluate postoperative changes in the neuropsychological function of cervical dystonia patients who had undergone deep brain stimulation (DBS) of the internal segment of the globus pallidus (GPi) and to investigate how DBS affects neuropsychological function by altering the neural networks of the brain. In 12 cervical dystonia patients, the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) was used to measure the preoperative and postoperative status of cervical dystonia, and the Seoul Neuropsychological Screening Battery was used to gather neuropsychological data. The data were analyzed using a Wilcoxon signed-rank test. The average improvement in the TWSTRS score at the time of the postoperative neuropsychological battery was 56.1 ±â€¯26.8%. In the neuropsychological battery, inhibitory control, as evaluated by the Stroop test, was significantly decreased after GPi DBS. The average pre-/postoperative Stroop test word and color reading correct response score were 107.9/99.2 (P = 0.043) and 85.3/75.8 (P = 0.032), respectively. The observed neuropsychological consequence of GPi DBS in this study, i.e., decreased inhibitory control, implies that electrical stimulation of the GPi may alter brain networks via the centromedian-parafascicular nuclear complex, suppressing the inhibitory control function of the prefrontal cortex.

Utility of the Lateral Base Dural Tacking Method in Cord Tumor Surgery Performed Using Unilateral Hemilaminectomy: A Comparison of Dural Window Widths.

OBJECTIVE: Unilateral hemilaminectomy, which is used to remove spinal cord tumors, is simpler than laminoplastic laminotomy and affords certain biomechanical advantages. However, both incomplete tumor removal and inadvertent infliction of spinal cord damage attributable to the narrow surgical corridor remain of concern. When a spinal cord tumor is to be removed, it is important to ensure that the dural window along the surgical corridor is of adequate width. This study aimed to determine that the utility of lateral base dural tacking (LBT) method when cord tumor surgery is performed using a unilateral hemilaminectomy-a comparison of dural window widths with a traditional dural tack-up and a suspending-out (DSO) method with the aid of digital image-analysis software. METHODS: Twenty-one consecutive patients who had intradural-extramedullary spinal cord tumors removed using a unilateral hemilaminectomy were included in the study and analyzed retrospectively. We acquired DSO and LBT dural window images using surgical microscopes under identical conditions in consecutive order and then removed the tumors using the LBT method. We used digital image-analysis software to analyze the images quantitatively. The pixel numbers of LBT and DSO window were compared using a paired t test. RESULTS: Twenty-one tumorous lesions were successfully removed without any major problems using a unilateral hemilaminectomy through LBT windows. The mean pixel numbers of the LBT and DSO windows were 126,787 ± 41,938 and 85,940 ± 21,638. The LBT windows were 46% larger than the DSO windows (P < 0.001). CONCLUSIONS: We objectively proved that the utility of the LBT method for widening the surgical corridor created during hemilaminectomy.

Implications of Mechanical Endovascular Thrombectomy for Acute Basilar and Posterior Cerebral Artery Occlusion.

OBJECTIVE: Protocols for posterior circulation ischemic stroke have not been established by randomized clinical trials. Mechanical endovascular thrombectomy (MET) devices are evolving, and many of these devices already developed or in development are suitable for posterior circulation MET. MATERIALS AND METHODS: We investigated the medical records of patients who underwent MET for posterior circulation ischemic stroke from January 2012 to August 2016. Fifteen patients were included. MET was performed in patients with or without injected intravenous tissue plasminogen activator. MET was considered in patients with a National Institute of Health Stroke Scale score of 4 or more, older than 18 years, with definite occlusion of the basilar artery or posterior cerebral artery (PCA), and who arrived at the hospital within 24 hours from onset. RESULTS: The direct catheter aspiration technique was used in five cases, and the stent retrieval technique was used in seven cases. The stent retrieval technique with the direct aspiration technique was used in three cases. Recanalization failed in two cases. Basilar occlusion without PCA involvement is the only effective factor of successful recanalization (p = 0.03). Successful recanalization (p = 0.005) and the presence of a posterior communicating artery (p = 0.005) affected the good outcome at discharge. CONCLUSION: An early diagnosis and active MET may improve the patient outcome. MET may help recanalization and good flow restoration and the potential for a good outcome.