Stereotactic and Functional Neurosurgery最新文献

Introduction: Tumor-related trigeminal neuralgia (TN) is a challenging condition to manage that can be treated with gamma knife radiosurgery (GKRS) by targeting the tumor, the trigeminal nerve, or both. However, data regarding the efficacy of this treatment are somewhat limited. The aim of this study was to report outcomes of GKRS for tumor-related TN from a cohort study.

Methods: Retrospective review of our GKRS database identified 41 patients with benign tumor-related TN treated with GKRS between 2014 and 2024. Background medical history, treatment outcomes and complications, and dosimetric data were obtained by chart review.

Results: The tumor, the trigeminal nerve alone, or a combination of both was targeted in 28, 7, and 6 patients, for a total of 47 GKRS procedures. Eight (24%) patients had pain control before GKRS targeting the tumor. Thirty (88%) and 11 (85%) patients had pain control after GKRS targeting the tumor and the trigeminal nerve, respectively. After a median follow-up of 63 months, pain recurred in 8 (24%) and 3 (23%) patients in the two groups. After tumor- and nerve-targeted GKRS, estimated rates of pain control at 1, 4, 7, and 10 years were 82%, 69%, 56%, and 56%, and 77%, 67%, 50%, and 50%, respectively. When GKRS targeting the tumor and the trigeminal nerve was considered as part of the same treatment, estimated rates of pain control at 1, 4, 7, and 10 years were 83%, 75%, 71%, and 71%. After tumor- and nerve-targeted GKRS, respectively, 5 (15%) and 3 (23%) patients developed persistent non-bothersome facial hypesthesia.

Conclusions: GKRS targeting the tumor is an effective, well-tolerated treatment for patients with tumor-related TN. More durable relief is achieved in some patients with second-stage GKRS targeting the trigeminal nerve but with additional facial sensory disturbances.

Background: Long-term ambulatory intracranial EEG is beginning to transform epilepsy care by revealing new insights into seizure patterns and treatment responses over the course of months to years. The feasibility of such monitoring was initially demonstrated through a dedicated recording system. Subsequently, brain-implanted neurostimulators became available with integrated recording functionality, revealing numerous clinically useful applications.

Summary: Chronic intracranial EEG allows long-term characterization of patient events, which can clarify which are epileptic, and also help identify unrecognized or subclinical seizures, which can vastly outnumber reported ones. Longitudinal recordings allow monitoring of epilepsy burden over the course of months to years, including responses to treatments such as neuromodulation and anti-seizure medications. Medication efficacy can be assessed in a matter of weeks rather than months. In patients with more than one potential localization, the predominant seizure focus can be identified, enabling further surgical options such as resection. Temporal patterns including circadian and multiday cycles may be revealed with the potential to enable temporal-specific treatments, seizure forecasts, and seizure warnings. Beyond direct clinical applications, ambulatory intracranial EEG has also opened up a new field of neuroscience in naturalistic environments.

Key messages: Long-term intracranial recordings have led to new discoveries about the individualized course of epilepsy and how it responds to treatment. They are clinically useful but are currently limited to patients with specific neurostimulators which are not available worldwide. Current systems allow long-term monitoring with intermittent EEG and/or hourly summary data but do not have continuous EEG availability. Expansion to patients without neurostimulators could provide broader clinical benefit. Scalp and implanted subscalp monitoring systems are now entering clinical care and may offer some of the same advantages as intracranial recording systems, although comparisons have not been made.

Background: In the 15 years since the first patient with drug-resistant epilepsy was treated by MR-guided laser interstitial thermal therapy (LITT), it has revolutionized the surgical treatment of epilepsy. Therapeutic targets have ranged from every form of epileptogenic lesion, including mesial temporal sclerosis (MTS), hypothalamic hamartomas (HHs), malformations of cortical development, low-grade epilepsy-associated tumors, and cerebral cavernous malformations (CCM), to MRI-normal epileptogenic zones characterized by stereoelectroencephalography (SEEG), to disconnection surgeries such as corpus callosotomy and even functional hemispherotomy (FH). Many series now support the general effectiveness and safety of LITT for epilepsy, although we are still in the period where increasing experience and technical advances are driving refinement in the therapy. Here, we provide a broad survey of the landscape of LITT for epilepsy and a perspective on future developments.

Summary: The largest experience is with stereotactic laser amygdalohippocampotomy for mesial temporal lobe epilepsy (MTLE), leading to seizure freedom (Engel I) in 57% of patients (N = 554), less effective than anterior temporal lobectomy but with significantly improved cognitive outcomes. Seizure-free rates are about 10% higher for MTS, with lower rates in MRI-normal MTLE. The largest experience in epileptogenic lesions is with HH where a pooled analysis found 77% of patients became seizure-free (N = 374), with up to 93% of patients becoming free of gelastic seizures. Experience with other lesions is more limited, with seizure freedom in 59% of patients with focal cortical dysplasias (N = 37), 80% of patients with periventricular nodular heterotopias (N = 39), and 88% of patients with CCMs (N = 39); 54% of patients with cortical tubers achieved Engel I or II outcomes. Outcomes in patients undergoing stereotactic laser corpus callosotomy (N = 82) or FH (N = 6) are similar to the results of open surgery.

Key messages: MR-guided LITT is becoming well established as a minimally invasive option for the treatment of drug-resistant epilepsy. While seizure freedom may in some circumstances be less than open resection, it offers improved therapeutic windows and, in some circumstances, provides surgical options where none existed previously. Moreover, it marries well with SEEG to offer a completely minimally invasive option. This combined with the increased therapeutic window and the lower level of surgical complications, pain, and even cost lowers the barrier to a potentially definitive surgical option for patients that have heretofore been reluctant. The future will see increased experience and technical advances in both laser technology and stereotactic delivery driving rapid global spread of LITT as a surgical tool in epilepsy.

Introduction: In 2015, directional leads have been released in Europe for deep brain stimulation (DBS) and have been particularly used for subthalamic nucleus (STN) DBS for Parkinson's disease (PD). In this study, we aimed to compare an omnidirectional and directional leads cohort of PD patients when it comes to clinical effectiveness and to assess the correlation with volume of tissue activated-target overlap (VTA-target).

Methods: A total of 60 consecutive patients were retrospectively included. Twenty-seven patients with bilateral directional leads were compared to 33 patients with bilateral omnidirectional leads. MDS-UPDRS part III scores, levodopa equivalent daily dose (LEDD), and VTA overlaps using both motor STN region and motor improvement sweet spot volume were compared at 12 months after surgery.

Results: There is a significantly higher LEDD reduction in the directional leads group (51.3% reduction vs. 42.7% reduction, p = 0.042) when compared to the omnidirectional group, with similar MDS-UPDRS III motor scores at 12 months. Omnidirectional leads patients had a significantly superior VTA-motor STN overlap volume than directional leads patients (32.01 mm3 vs. 20.38 mm3, p = 0.0226). In directional leads patients, LEDD reduction was correlated to VTA overlap with the overall motor improvement mean map sweet spot (R = 0.36, p = 0.036), which was not the case for omnidirectional leads patients (R = 0.11, p = 0.276). Forty-one percent of patients implanted with directional leads had a directional stimulation setting at 12 months, compared to 33% at 3 months follow-up. In directional leads patient's subgroup analysis, there was no significant difference in MDS UPDRS III scores, LEDD reduction, VTA overlaps with motor STN, or overall motor improvement mean map sweet spot between patients stimulated omnidirectionally and directionally at 12 months.

Conclusion: At 12 months, when compared to omnidirectional leads, directional leads manage with smaller VTA-target overlaps to obtain comparable MDS-UPDRS III scores with greater LEDD reduction in STN DBS for PD patients.

Background: Most patients suffering from cancer will face pain during the course of their disease. Pain is a source of major discomfort and alteration of quality of life. Pituitary targeting, initially reported as hypophysectomy, was first proposed to control endocrine cancer. Although this technique did not improve the overall tumoral control, it rapidly showed an interesting effect on cancer pain related to bone metastases. Due to the complications, this technique gradually decreased and finally fell into disuse. Recently, some authors have shown a regained interest in pituitary targeting using a radiosurgical procedure, in order to limit surgical complications, with interesting results. We performed a systematic review of the literature and meta-analysis with the aim of evaluating the outcome and complications of pituitary targeting and determining its current place in the management of cancer pain.

Summary: Twenty-four studies were included in this systematic review (700 patients). Nineteen studies reported the results of surgical and 5 studies of stereotactic radiosurgical pituitary targeting. Pain relief was reported in 82.2% and 93.5% for surgery and radiosurgery, respectively. On the long-term, pain relief was maintained in 80.2% and 88.6% for surgery and radiosurgery, respectively. Complications varied among treatment modalities, with diabetes insipidus being the most common complication.

Key messages: Pituitary targeting remains an attractive option for refractory cancer-related pain after failure of traditional therapies. Radiosurgery is a promising treatment modality due to its high success rate and reduced risk of complications and should be recommended over surgery whenever possible. Pain relief is presumably related to a neuromodulation mechanism.

Background: Resistant cancer pain (RCP) remains a challenge in oncology, affecting patients whose pain persists despite guideline-based treatment. While advancements in pharmacological and interventional strategies have improved cancer pain management, barriers such as opioid access restrictions, provider knowledge gaps, and underutilization of specialized pain interventions contribute to inadequate relief. Understanding the epidemiology, classification, and risk factors for RCP is essential for improving treatment.

Summary: This review examines the prevalence, pathophysiology, and burden of RCP, highlighting its impact on quality of life and healthcare systems. Pain severity is commonly assessed using numerical rating scales, but comprehensive frameworks like the Edmonton Classification System for Cancer Pain (ECS-CP) provide better insight into complex pain syndromes. Breakthrough pain, neuropathic pain, and cancer-induced bone pain are frequently linked to treatment resistance. While opioids remain central to pharmacological management, many patients require multimodal approaches, including adjuvant analgesics, interventional procedures, and radiation therapy. Neurosurgical options such as cordotomy, intrathecal drug delivery, and myelotomy offer pain relief in select cases but are underutilized due to limited awareness and training.

Key messages: RCP remains a major unmet medical need, affecting many cancer patients despite advances in pain management. Effective treatment requires a multimodal, individualized approach integrating pharmacological, interventional, and neurosurgical strategies. While neurosurgical interventions provide substantial relief in selected patients, their use is often limited by referral delays and lack of provider awareness. Overcoming systemic barriers, refining pain classification, and expanding access to specialized pain management are essential to improving RCP care.

Introduction: Magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy effectively treats medication-resistant essential tremor (ET). Usually, intracranial calcifications are excluded as no-pass zones because of their low penetrability which may limit the effectiveness of treatment and lead to unintended side effects. This case report illustrates the efficacy of unilateral MRgFUS for tremor control in a patient with extensive basal ganglia calcifications due to Fahr's disease.

Case presentation: A 69-year-old right-handed male with debilitating Fahn-Tolosa-Marin grade 3-4 bilateral hand tremor underwent unilateral left MRgFUS thalamotomy. The treatment involved careful preoperative planning to accommodate his extensive basal ganglia calcifications, element path consideration, and skull density ratio to ensure accurate and effective lesioning. Posttreatment, the patient exhibited complete abolition of tremor on the treated side with minor transient dysarthria and imbalance. Follow-up at 12 weeks posttreatment showed sustained tremor relief and an absence of any adverse effects, validating the procedural adjustments made to accommodate the unique challenges posed by his intracranial calcifications.

Conclusion: MRgFUS can be safely and effectively applied in certain patients with extensive basal ganglia calcifications - in this case, due to Fahr's disease. This case report suggests expanding the application of MRgFUS to patients with extensive intracranial calcifications who previously might not have been considered suitable candidates for MRgFUS.

Background: Although patients with drug-resistant epilepsy (DRE) have a <5% chance of seizure freedom with continued polypharmacy, surgical interventions remain underutilized. One potential driver of this trend is patient perceived fear of open surgery. Focused ultrasound is an incisionless, minimally invasive technique that has been used to treat epilepsy and has the potential to have a larger footprint within the epilepsy surgeon's armamentarium.

Summary: A brief overview of the underutilization of epilepsy surgery, the epilepsy treatment landscape, and current and emerging applications of focused ultrasound for DRE will be discussed. This article includes a brief comparison of focused ultrasound with other alternatives to open epilepsy surgery and a summary and appraisal of the existing literature.

Key messages: Focused ultrasound serves as a versatile, minimally invasive option for patients with contraindications to or concerns with open surgery or radiation exposure. Preliminary studies indicate disease-modifying benefit of high-intensity focused ultrasound (HIFU) ablation and potential neuromodulatory benefit and increased blood-brain barrier permeability of low-intensity focused ultrasound (LIFU). Higher level evidence is needed to elucidate the efficacy of LIFU and HIFU for the treatment of epilepsy. However, focused ultrasound is an emerging treatment modality that has the potential to transcend the traditional ablation paradigm and alter the cellular composition of epileptic networks for therapeutic effect.

Background: Epilepsy is one of the most prevalent chronic neurological disorders, with approximately 30% of patients not responding to medical treatment. In selected cases, drug-resistant epilepsy can be safely managed with neuromodulation, leading to a significant reduction in disease burden.

Summary: Experimental evidence has demonstrated that the primary neuromodulation modalities, vagus nerve stimulation (VNS), deep brain stimulation (DBS), and responsive neurostimulation (RNS), can modulate various brain circuits and reduce epileptic activity by decreasing neuronal hypersynchronization through multiple mechanisms at the molecular, cellular, and network levels. However, clear criteria for selecting among devices, determining optimal stimulation targets, and defining effective parameters to improve outcomes remain elusive.

Key messages: Neuromodulation represents a promising treatment strategy for drug-resistant epilepsy. Nevertheless, further research is essential to refine clinical decision-making. In this review, we discuss the evolution of neuromodulation technologies, with a focus on the indications, advantages, disadvantages, and future directions of VNS, DBS, and RNS.

Introduction: Postherpetic neuralgia (PHN) is a pain syndrome that develops within few months after the acute herpetic outbreak. The pain may be accompanied by specific cutaneous signs in the distribution of affected dermatomes and feel unbearable reaching up to 9-10/10 on visual analog scale (VAS). Despite the introduction of new medications, drug resistance develops in at least 50% of cases. Neuromodulation techniques such as spinal cord stimulation (SCS) and peripheral nerve stimulation (PNS) are considered as ones of the last resorts for PHN treatment, especially in pharmacoresistant patients. Recently, several studies with limited number of cases have shown high efficiency of neuromodulation (regression of pain syndrome in more than 82% of cases) after SCS in PHN patients, but these findings require further confirmation and have not been supported by large RCTs.

Methods: Initially, 32 patients diagnosed with chronic drug-resistant PHN underwent a trial of SCS. Based on the trial results, a decision was made whether to implant a permanent SCS system. The condition of all patients implanted with SCS system was assessed using the VAS, SF-36, Patient Global Impression of Change (PGIC), and Medicine Quantification Scale, version III (MQS) questionnaires before the surgery and in the long-term follow-up. We also conducted systematic follow-up of patients who did not pass the test stimulation stage, using them as a control group to track the levels of pain. The hypothesis of normal distribution for quantitative values was tested using Shapiro-Wilk tests.

Results: During the trial period, tonic spinal stimulation was effective in 16 out of 32 (50%) patients with drug-resistant PHN. Among 14 patients with implanted stimulators, a significant pain reduction (more than 50% from the baseline) was observed in 10 patients (71.4%). The pain level in patients with a tonic SCS was statistically lower than in patients receiving conservative therapy. For the entire group of patients with implanted SCS, a significant improvement was also observed in results of SF-36, PGIC, and MQS.

Conclusion: Our clinical series demonstrates that tonic SCS was effective in 50% of patients with refractory PHN undergoing SCS trial. Significant improvement in pain control obtained during the long-term follow-up in patients treated with tonic SCS improves the quality of life and reduces the need for analgesic medications.