Movement disorder Deep brain stimulation Hybridization: Patient and caregiver outcomes.

Background and Objectives: Deep brain stimulation (DBS) is a well-established surgical treatment for certain movement disorders and involves the implantation of brain electrodes connected to implantable pulse generators (IPGs). As more device manufacturers have entered the market, some IPG technology has been designed to be compatible with brain electrodes from other manufacturers, which has facilitated the hybridization of implant technology. The aim of this study was to assess the benefits of hybridization of non-rechargeable, constant voltage IPGs to rechargeable, constant current IPGs. Methods: A list of DBS movement disorder patients who had their non-rechargeable, constant voltage IPGs replaced with rechargeable, constant current IPGs from a different manufacturer was compiled. Structured surveys of these patients, and their caregivers when applicable, were undertaken to determine both patient and caregiver satisfaction in this DBS hybridization strategy. Results: Eighteen patients met inclusion criteria and twelve patients or their caregivers completed the structured survey (67% response rate). Nine patients had Parkinson's disease (75%), three had essential tremor (25%). Nine (75%) were converted from bilateral single-channel IPGs, and three (25%) were converted from a unilateral dual-channel IPGs. Overall, 92% of patients and caregivers surveyed reported improvement or no change in their symptoms, 92% reported a decrease or no change in their medication requirements, and 92% report they are satisfied or very satisfied with their IPG hybridization and would recommend the surgery to similar patients. There were no immediate surgical complications. Conclusion: In this series of movement disorder DBS patients, surgery was safe and patient and caregiver satisfaction were high with a hybridization of non-rechargeable, constant voltage IPGs to rechargeable, constant current IPGs.

Infections and hardware salvage after deep brain stimulation surgery: a single-center study and review of the literature.

AIMS: Infection of hardware is a serious complication after deep brain stimulation (DBS), as this may result in additional surgery, cost and loss of treatment benefit for the patient. We report the incidence and management of infections after DBS in a single institution over the past 11 years. METHODS: A database of 270 patients with 484 implants was used in the study. Incidence, clinical characteristics and management of infections were analyzed. RESULTS: The overall infection rate was 9.3% (25/270) by patients and 6.8% (33/484) by episode/implants. The median time of infection after implantation was 64 days. Only 7/33 episodes (21.2%) occurred within 30 days after surgery, 22/33 episodes (66.7%) within 6 months and 28/33 episodes (84.8%) within 12 months. There was no age difference between infected and noninfected patients, while comorbidities were more frequent in the former. Infection rates before and after January 2003 were 14.3 and 4.9%, respectively. The rate of complete and partial hardware salvage was 30.3 and 21.2% while that of complete hardware removal was 48.5%. Patients with deep purulent infections and patients with Staphylococcus aureus as the causative organism were more likely to have their hardware removed. CONCLUSIONS: The incidence of hardware infections declined significantly over time. Improvements in hardware and implantation techniques may be responsible. Hardware can often be completely or partly saved in infected patients.

Stimulation of the globus pallidus internus in a patient with DYT1-positive primary generalized dystonia: a 10-year follow-up.

The authors report the case of DYT1-positive primary generalized dystonia refractory to medical management that was successfully treated with continuous deep brain stimulation of the internal segment of the globus pallidus. Prior studies have shown that neuromusculoskeletal deficits can remain permanent if early surgical intervention is not undertaken. The authors report prolonged efficacy and safety over a 10-year period in a 28-year-old man.

Craniotomy for subdural hematoma after deep brain stimulation surgery: Outcomes and satisfaction in a case series of two patients.

OBJECTIVE: To determine whether salvage of DBS hardware is beneficial for Parkinson's Disease (PD) patients by looking at follow-up patient's outcomes and satisfaction after their craniotomy operation. PATIENTS AND METHODS: This was a retrospective review of a prospective, single-center deep brain stimulation (DBS) database between 2002-2016 identifying patients with PD who developed subdural hematomas (SDH) due to trauma after their DBS surgery. Of the 636 DBS cases that were performed, 3 PD-DBS patients with significant traumatic SDH managed via craniotomy were identified. Out of these 3 patients, only 2 permitted outcome analysis. At follow-up, functional and neurologic status, UPDRS motor score, and overall satisfaction with DBS were assessed. RESULTS: Two patients were followed for a period of 10 and 9 months. At last follow-up, the DBS settings in patient 1 increased from a stimulation amplitude of 3.5 V to 4.5 V on the right and 3.3 V to 6.0 V on the left with an increase in the pulse width as well (70-80 ms and 80-140 ms on the right and left, respectively). Stimulation frequency remained 160 Hz on the right while increasing from 145 to 160 Hz on the left. Patient 2 experienced an increase in stimulation amplitude from 4.5 V to 4.8 V on the right while remaining the same on the left. Pulse width increased from 60 to 70 ms bilaterally as well as the frequency (160-185 Hz bilaterally). Despite craniotomy, both patients experienced substantial improvement in UPDRS motor score with DBS at last follow-up (53-25 and 20-17 for patient 1 and 2, respectively). At last follow-up, CT imaging provided evidence of complete SDH resolution with no persistent hemorrhage, mass effect or any obvious lead displacement. Patients expressed satisfaction with DBS and affirmed that they would undergo surgery again for the same outcome. CONCLUSION: Patients with PD are at higher risk for falls and may experience an increased risk of falling associated with SDH in the post-operative period after DBS implantation. Despite brain shift from SDH potentially distorting DBS leads, DBS implants still provided significant benefit in patients requiring craniotomy for SDH and patient satisfaction with DBS remained high. Salvage of DBS hardware is recommended since significant symptomatic improvement with DBS programming may still be attainable even in the setting of emergent craniotomy for SDH.

Disease Stabilization of DYT1-Positive Primary Generalized Dystonia With Deep Brain Stimulation of the Globus Pallidus Interna: A 15-Year Follow-up.

BACKGROUND AND IMPORTANCE: Primary generalized dystonia (PGD) is a genetic form of dystonia that frequently displays pharmacological resistance and progresses quickly after onset. Deep brain stimulation (DBS) has been used successfully to treat refractory dystonia, specifically globus pallidus interna (GPi) DBS for DYT1-positive PGD patients. Long-term follow-up of the safety and efficacy falls short of the longevity seen in other diseases treated with DBS. CASE PRESENTATION: A male patient presented for neurosurgical evaluation with scapular winging, hand contractures, and violent truncal spasms, which forced him to be bedridden. After failing conservative therapy, the 18-yr-old patient was implanted with bilateral GPi-DBS. DBS parameter adjustments were made primarily within the first 3 yr after implantation, with nominal changes thereafter. Initial settings were contact of 3 + 0-, amplitude of 4.9 V, frequency of 185 Hz, and pulse width of 270 µsec on the left and 3 + 0-, 2.8 V, 185 Hz, and 120 µsec on the right. Current settings are 3 + 2 + 1-, 5.2 V, 130 Hz, 330 µsec on the left and 3 + 0-, 3.5 V, 185 Hz, and 180 µsec on the right and have been relatively unchanged in the past 4 yr. Unified dystonia rating scale scores reveal a significant decrease in dystonic symptoms. CONCLUSION: While prior reports have shown that GPi-DBS is effective for dystonia, this is the first with 15 yr of long-term follow-up showing disease stabilization, suggesting that stimulation is efficacious and can potentially prevent disease progression. This report reaffirms previous reports that recommend early surgical intervention before the onset of permanent musculoskeletal deficits.

Mapping of microstimulation evoked responses and unit activity patterns in the lateral hypothalamic area recorded in awake humans. Technical note.

Major contributions to the understanding of human brain function have come from detailed clinical reports of responses evoked by electrical stimulation and specific brain regions during neurosurgical procedures in awake humans. In this study, microstimulation evoked responses and extracellular unit recordings were obtained intraoperatively in 3 awake patients undergoing bilateral implantation of deep brain stimulation electrodes in the lateral hypothalamus. The microstimulation evoked responses exhibited a clear anatomical distribution. Anxiety was most reliably evoked by stimulation directed ventromedially within or adjacent to the ventromedial nucleus of the hypothalamus, nausea was most reliably evoked by stimulation directed at the center of the lateral hypothalamus, and paresthesias were most reliably evoked by stimulation at the border of the lateral hypothalamus and basal nuclei. Regarding the unit recordings, the firing rates of individual neurons did not have an anatomical distribution, but a small subpopulation of neurons located at the border of the lateral hypothalamus and basal nuclei exhibited a fast rhythmically bursting behavior with an intraburst frequency of 200-400 Hz and an interburst frequency of 10-20 Hz. Based on animal studies, the lateral hypothalamic area and surrounding hypothalamic nuclei are putatively involved with a variety of physiological, behavioral, and sensory functions. The lateral hypothalamus is situated to play a dynamic and complex role in human behavior and this report further shows that to be true. In addition, this report should serve as a valuable resource for future intracranial work in which accurate targeting within this region is required.

Long-term results of thalamic deep brain stimulation for essential tremor.

OBJECT: Deep brain stimulation (DBS) of the ventral intermediate nucleus of the thalamus (VIM) has proven to be efficacious in the treatment of essential tremor (ET). The authors report on long-term follow-up of a series of patients treated at 1 institution by 1 neurosurgeon. METHODS: Thirty-four patients with ET received unilateral or bilateral VIM DBS. The tremor and handwriting components of the Fahn-Tolosa-Marin clinical tremor rating scale were assessed pre- and postoperatively. Visual analog scale scores for overall patient satisfaction and tremor control were recorded. Stimulation parameters at different intervals after surgery were also recorded. RESULTS: The average follow-up period was 56.9 months. The average tremor score improved from 3.27 preoperatively to 0.64 postoperatively (on stimulation; p < 0.001) and the average handwriting score improved from 2.94 to 0.89 (p < 0.001). The average visual analog scale score for overall satisfaction was 8.12 and for tremor control was 1.43. Overall, there was an 80.4% improvement in tremor and 69.7% improvement in handwriting. In 12 patients both tremor and handwriting scores were compared between 57.3 months and 90.7 months after surgery and no significant changes were discovered. Comparison of stimulation parameters at onset and at 1-3, 3-5, 5-7, and > 7 years after surgery showed significant differences, with a gradual increase in stimulation parameters within 5 years after surgery. The overall hardware-related complication rate was 23.5%. CONCLUSIONS: Deep brain stimulation of the VIM is an efficient and safe treatment for ET. Tremor and handwriting improvements in long-term follow-up are stable. The patients' perception of their outcome is quite good. However, tolerance may develop in some patients requiring changes in stimulation parameters.

Induction of panic attack by stimulation of the ventromedial hypothalamus.

Panic attacks are sudden debilitating attacks of intense distress often accompanied by physical symptoms such as shortness of breath and heart palpitations. Numerous brain regions, hormones, and neurotransmitter systems are putatively involved, but the etiology and neurocircuitry of panic attacks is far from established. One particular brain region of interest is the ventromedial hypothalamus (VMH). In cats and rats, electrical stimulation delivered to the VMH has been shown to evoke an emotional "panic attack-like" escape behavior, and in humans, stimulation targeting nuclei just posterior or anterior to the VMH has reportedly induced panic attacks. The authors report findings obtained in an awake patient undergoing bilateral implantation of deep brain stimulation electrodes into the hypothalamus that strongly implicates the VMH as being critically involved in the genesis of panic attacks. First, as the stimulating electrode progressed deeper into the VMH, the intensity of stimulation required to evoke an attack systematically decreased; second, while stimulation of the VMH in either hemisphere evoked panic, stimulation that appeared to be in the center of the VMH was more potent. Thus, this evidence supports the role of the VMH in the induction of panic attacks purported by animal studies.

Fast-track programming and rehabilitation model: a novel approach to postoperative deep brain stimulation patient care.

OBJECTIVE: To propose a new model of integrated, multidisciplinary postoperative care of the patients with deep brain stimulation (DBS). DESIGN: Observational cohort study with follow-up at 3 months and 1 year. SETTING: Academic medical center movement disorder clinic. PARTICIPANTS: Seventy-three consecutive patients with medically refractory Parkinson's disease underwent bilateral DBS. Patients were then transferred directly to an inpatient rehabilitation facility. INTERVENTION: DBS and inpatient programming and rehabilitation. Simultaneous programming and rehabilitation was carried out by a multidisciplinary team. MAIN OUTCOME MEASURES: The FIM instrument, Unified Parkinson Disease Rating Scale (UPDRS), and levodopa dosage. RESULTS: The average rehabilitation stay was 17.3 days, with a mean of 6.2 stimulator adjustments during that time. FIM scores improved from 62.1 (admission) to 98.5 (discharge), an average improvement of 36.4 (58.6%). Average UPDRS scores improved from 52.5 (preoperative off) and 30.1 (preoperative on) to 20.4 (3mo postoperative on-medication, on-stimulation), a 32.2% improvement from the preoperative on score. Levodopa dosages decreased by an average of 48.3% (all P<.001). CONCLUSIONS: We describe our fast-track protocol, which allows for rapid DBS programming and tapering of Parkinson's medications. It also provides for treatment of concomitant medical and psychologic problems and optimized physical performance.