Parkinson's disease and deep brain stimulator placement

Cardiac arrest during deep brain stimulation: A case report

We present the case of a 54-year-old male with severe Parkinson's disease and chronic, non-reversible pulmonary artery hypertension who had seizures and a cardiorespiratory arrest during surgery for deep brain stimulation, a minimally invasive procedure usually associated with a low risk of complications. This case illustrates how perioperative changes in antiparkinsonian therapy in patient with multiple comorbidities may significantly affect the risk profile.

Asleep DBS under ketamine sedation: Proof of concept

BACKGROUND

Deep brain stimulation (DBS) is commonly and safely performed for selective Parkinson's disease patients. Many centers perform DBS lead positioning exclusively under local anesthesia, to optimize brain microelectrode recordings (MER) and testing of stimulation-related therapeutic and side effects. These measures enable physiological identification of the DBS borders and subdomains based on electrophysiological properties like firing rates and patterns, intra-operative evaluation of therapeutic window, and improvement of lead placement accuracy. Nevertheless, due to the challenges of awake surgery, some centers use sedation or general anesthesia, despite the distortion of discharge properties and interference with clinical testing, resulting in potential impact on surgical outcomes. Thus, there is a need for a novel anesthesia regimen that enables sedation without compromising intra-operative monitoring.

OBJECTIVE

This open-label study investigates the use of low-dose ketamine for conscious sedation during microelectrode recordings and lead positioning in subthalamic nucleus (STN) DBS for Parkinson's disease patients.

METHODS

Three anesthetic regimens were retrospectively compared in 38 surgeries (74 MER trajectories, 5962 recording sites) across three DBS centers: 1) Interleaved propofol-ketamine (PK), 2) Interleaved propofol-awake (PA), and 3) Fully awake (AA).

RESULTS

All anesthesia regimens achieved satisfactory MER. Detection of STN borders and subdomains by expert electrophysiologist was similar between the groups. Electrophysiological signature of the STN under ketamine was not inferior to either control group. All patients completed stimulation testing.

CONCLUSIONS

This study supports a low-dose ketamine anesthesia regimen for DBS which allows microelectrode recordings and stimulation testing that are not inferior to those conducted under awake and propofol-awake regimens and may optimize patient experience. A prospective double-blind study that would also compare patients' satisfaction level and clinical outcome should be performed to confirm these findings.

The Opioid-Sparing Effect of Perioperative Dexmedetomidine Plus Sufentanil Infusion during Neurosurgery: A Retrospective Study

Background: Approximately 60% of patients experience moderate-to-severe pain after neurosurgery, which primarily occurs in the first 24–72 h. Despite this, improved postoperative analgesia solutions after neurosurgery have not yet been devised. This retrospective study was conducted to evaluate the effect of intra- and post-operative infusions of dexmedetomidine (DEX) plus sufentanil on the quality of postoperative analgesia in patients undergoing neurosurgery.

Methods: One hundred and sixty-three post-neurosurgery patients were divided into two groups: Group D (DEX infusion at 0.5 μg·kg⁻¹ for 10 min, then adjusted to 0.3 μg·kg⁻¹·h⁻¹ until incision suturing) and Group ND (no DEX infusion during surgery). Patient-controlled analgesia was administered for 72 h after surgery (Group D: sufentanil 0.02 μg·kg⁻¹·h⁻¹ plus DEX 0.02 μg·kg⁻¹·h⁻¹, Group ND: sufentanil 0.02 μg·kg⁻¹·h⁻¹) in this retrospective study. The primary outcome measure was postoperative sufentanil consumption. Hemodynamics, requirement of narcotic, and vasoactive drugs, recovery time and the incidence of concerning adverse effects were recorded. Pain intensity [Visual Analogue Scale (VAS)], Ramsay sedation scale (RSS) and Bruggemann comfort scale (BCS) were also evaluated at 1, 4, 8, 12, 24, 48, and 72 h after surgery.

Results: Postoperative sufentanil consumption was significantly lower in Group D during the first 72 h after surgery (P < 0.05). Compared with Group ND, heart rate (HR) in Group D was significantly decreased from intubation to 20 min after arriving at post anesthesia care unit (PACU), while mean arterial pressure (MAP) in Group D was significantly decreased from intubation to 5 min after arriving at PACU (P < 0.05). The intraoperative requirements for sevoflurane, remifentanil, and fentanyl were approximately 35% less in Group D compared with Group ND. VAS at rest at 1, 4, and 8 h and with cough at 12, 24, 48, and 72 h after surgery were significantly lower in Group D (P < 0.05). Compared with Group ND, patients in Group D showed lower levels of overall incidence of tachycardia, hypertension, nausea, and vomiting (P < 0.05). There were no significant differences between the two groups in terms of baseline clinical characteristics, recovery time, RSS, and BCS (P > 0.05).

Conclusions: DEX (0.02 μg·kg⁻¹·h⁻¹) plus sufentanil (0.02 μg·kg⁻¹·h⁻¹) could reduce postoperative opioid consumption and concerning adverse adverse effects, while improving pain scores. However, it did not influence RSS and BCS during the first 72 h after neurosurgery.

Anesthetic challenges for deep brain stimulation: a systematic approach

Ablative intracranial surgery for Parkinson's disease has advanced to embedding electrodes into precise areas of the basal ganglia. Electrode implantation surgery, referred to as deep brain stimulation (DBS), is preferred in view of its reversibility, adjustability, and capability to be safely performed bilaterally. DBS is been increasingly used for other movement disorders, intractable tremors epilepsy, and sometimes chronic pain. Anesthesiologists need to amalgamate the knowledge of neuroanatomical structures and surgical techniques involved in placement of microelectrodes in defined cerebral target areas. Perioperative verbal communication with the patient during the procedure is quintessential and may attenuate the need for pharmacological agents. This review will endeavor to assimilate the present knowledge regarding the patient selection, available/practiced anesthesia regimens, and perioperative complications after our thorough search for literature published between 1991 and 2013.

Preservation of microelectrode recordings with non-GABAergic drugs during deep brain stimulator placement in children

OBJECT

Deep brain stimulation (DBS) has become accepted therapy for intractable dystonia and other movement disorders. The accurate placement of DBS electrodes into the globus pallidus internus is assisted by unimpaired microelectrode recordings (MERs). Many anesthetic and sedative drugs interfere with MERs, requiring the patient to be awake for target localization and neurological testing during the procedure. In this study, a novel anesthetic technique was investigated in pediatric DBS to preserve MERs.

METHODS

In this paper, the authors describe a sedative/anesthetic technique using ketamine, remifentanil, dexmedetomidine, and nicardipine in 6 pediatric patients, in whom the avoidance of GABAergic stimulating drugs permitted excellent surgical conditions with no detrimental effects on intraoperative MERs. The quality of the MERs, and the frequency of its use in making electrode placement decisions, was reviewed.

RESULTS

All 6 patients had good-quality MERs. The data were of sufficient quality to make a total of 9 trajectory adjustments.

CONCLUSIONS

Microelectrode recordings in pediatric DBS can be preserved with a combination of dexmedetomidine and ketamine, remifentanil, and nicardipine. This preservation of MERs is particularly crucial in electrode placement in children.

Influence of propofol and fentanyl on deep brain stimulation of the subthalamic nucleus

We investigated the effect of propofol and fentanyl on microelectrode recording (MER) and its clinical applicability during subthalamic nucleus (STN) deep brain stimulation (DBS) surgery. We analyzed 8 patients with Parkinson's disease, underwent bilateral STN DBS with MER. Their left sides were done under awake and then their right sides were done with a continuous infusion of propofol and fentanyl under local anesthesia. The electrode position was evaluated by preoperative MRI and postoperative CT. The clinical outcomes were assessed at six months after surgery. We isolated single unit activities from the left and the right side MERs. There was no significant difference in the mean firing rate between the left side MERs (38.7 ± 16.8 spikes/sec, n=78) and the right side MERs (35.5 ± 17.2 spikes/sec, n=66). The bursting pattern of spikes was more frequently observed in the right STN than in the left STN. All the electrode positions were within the STNs on both sides and the off-time Unified Parkinson's Disease Rating Scale part III scores at six months after surgery decreased by 67% of the preoperative level. In this study, a continuous infusion of propofol and fentanyl did not significantly interfere with the MER signals from the STN. The results of this study suggest that propofol and fentanyl can be used for STN DBS in patients with advanced Parkinson's disease improving the overall experience of the patients.

Lewy body dementia: the impact on patients and caregivers

Lewy body dementia (LBD) is the second most common neurodegenerative dementia in older adults, yet there remains a delay in diagnosis that limits healthcare providers’ ability to maximize therapeutic outcomes and enhance patient and caregiver quality of life. The impact of LBD on patients includes limiting the potential exposure to medications that may cause adverse outcomes, and addressing how the disease manifestations, such as autonomic features and behavior, affect quality of life. LBD impact on caregivers has been discussed to a greater degree in the literature, and there is clear evidence of caregiver burden and grief associated with disease manifestations. Other common caregiving concerns, such as access to care, prevention of hospitalization, managing behavior, and reviewing prognosis and nursing home placement, are important to comprehensively address the needs of patients with LBD and their caregivers.

MR-guided focused ultrasound surgery, present and future

MR-guided focused ultrasound surgery (MRgFUS) is a quickly developing technology with potential applications across a spectrum of indications traditionally within the domain of radiation oncology. Especially for applications where focal treatment is the preferred technique (for example, radiosurgery), MRgFUS has the potential to be a disruptive technology that could shift traditional patterns of care. While currently cleared in the United States for the noninvasive treatment of uterine fibroids and bone metastases, a wide range of clinical trials are currently underway, and the number of publications describing advances in MRgFUS is increasing. However, for MRgFUS to make the transition from a research curiosity to a clinical standard of care, a variety of challenges, technical, financial, clinical, and practical, must be overcome. This installment of the Vision 20∕20 series examines the current status of MRgFUS, focusing on the hurdles the technology faces before it can cross over from a research technique to a standard fixture in the clinic. It then reviews current and near-term technical developments which may overcome these hurdles and allow MRgFUS to break through into clinical practice.

Asleep-awake-asleep craniotomy: a comparison with general anesthesia for resection of supratentorial tumors

The anesthetic plan for patients undergoing awake craniotomy, when compared to craniotomy under general anesthesia, is different, in that it requires changes in states of consciousness during the procedure. This retrospective review compares patients undergoing an asleep-awake-asleep technique for craniotomy (group AW: n = 101) to patients undergoing craniotomy under general anesthesia (group AS: n = 77). Episodes of desaturation (AW = 31% versus AS = 1%, p < 0.0001), although temporary, and hypercarbia (AW = 43.75 mmHg versus AS = 32.75 mmHg, p < 0.001) were more common in the AW group. The mean arterial pressure during application of head clamp pins and emergence was significantly lower in AW patients compared to AS patients (pinning 91.47 mmHg versus 102.9 mmHg, p < 0.05 and emergence 84.85 mmHg versus 105 mmHg, p < 0.05). Patients in the AW group required less vasopressors intraoperatively (AW = 43% versus AS = 69%, p < 0.01). Intraoperative fluids were comparable between the two groups. The post anesthesia care unit (PACU) administered significantly fewer intravenous opioids in the AW group. The length of stay in the PACU and hospital was comparable in both groups. Thus, asleep-awake-asleep craniotomies with propofol-dexmedetomidine infusion had less hemodynamic response to pinning and emergence, and less overall narcotic use compared to general anesthesia. Despite a higher incidence of temporary episodes of desaturation and hypoventilation, no adverse clinical consequences were seen.

Review article: anesthetic management of patients undergoing deep brain stimulator insertion

Deep brain stimulation is used for the treatment of patients with neurologic disorders who have an alteration of function, such as movement disorders and other chronic illnesses. The insertion of the deep brain stimulator (DBS) is a minimally invasive procedure that includes the placement of electrodes into deep brain structures for microelectrode recordings and intraoperative clinical testing and connection of the DBS to an implanted pacemaker. The anesthetic technique varies depending on the traditions and requirements of each institution performing these procedures and has included monitored anesthesia with local anesthesia, conscious sedation, and general anesthesia. The challenges and demands for the anesthesiologist in the care of these patients relate to the specific concerns of the patients with functional neurologic disorders, the effects of anesthetic drugs on microelectrode recordings, and the requirements of the surgical procedure, which often include an awake and cooperative patient. The purpose of this review is to familiarize anesthesiologists with deep brain stimulation by discussing the mechanism, the effects of anesthetic drugs, and the surgical procedure of DBS insertion, and the perioperative assessment, preparation, intraoperative anesthetic management, and complications in patients with functional neurologic disorders.