The Effectiveness of the Stereotactic Burr Hole Technique for Deep Brain Stimulation

Deep brain stimulation (DBS) is performed by burr hole surgery. In microelectrode recording by multi-channel parallel probe, because all microelectrodes do not always fit in the burr hole, additional drilling to enlarge the hole is occasionally required, which is time consuming and more invasive. We report a stereotactic burr hole technique to avoid additional drilling, and the efficacy of this novel technique compared with the conventional procedure. Ten patients (20 burr holes) that received DBS were retrospectively analyzed (5 in the conventional burr hole group and 5 in the stereotactic burr hole group). In the stereotactic burr hole technique, the combination of the instrument stop slide of a Leksell frame and the Midas Rex perforator with a 14-mm perforator bit was attached to the instrument carrier slide of the arc in order to trephine under stereoguidance. The efficacy of this technique was assessed by the number of additional drillings. Factors associated with additional drilling were investigated including the angle and skull thickness around the entry points. Four of the 10 burr holes required additional drilling in the conventional burr hole group, whereas no additional drilling was required in the stereotactic burr hole group (p = 0.043). The thicknesses in the additional drilling group were 10.9 ± 0.9 mm compared to 9.1 ± 1.2 mm (p = 0.029) in the non-additional drilling group. There were no differences in the angles between the two groups. The stereotactic burr hole technique contributes to safe and exact DBS, particularly in patients with thick skulls.     

Stabilization clamp for insertion of deep brain stimulation electrodes: technical note

BACKGROUND: Deep brain stimulation (DBS) electrodes are being implanted with increasing frequency for the management of movement disorders and chronic pain. Success with this neuro-augmentative technique requires accurate electrode lead placement. In order to enhance accuracy of final lead placement and ease of insertion, we describe a useful and reliable DBS electrode lead stabilization device developed and used at our centre. MATERIALS AND METHODS: The DBS electrode stabilization device consists of a 2-clamp system designed to fit the Leksell stereotactic frame. The clamps work in series to secure the stereotactic lead at the time of its final positioning in the desired subcortical target without the need of fluoroscopic control. RESULTS: The DBS electrode stabilization device has been used in 30 patients for 54 electrode implantations at our institution since 2000. Postoperative magnetic resonance imaging was performed in all cases and confirmed accurate placement of the electrodes. CONCLUSIONS: Accurate electrode lead placement is critical for the clinical efficacy of DBS systems. The simple and reliable stabilization device described here is easy to operate and enhances the final placement accuracy of DBS electrode leads.     

Ultrasound-guided aspiration of brain abscesses through a single burr hole.

Surgical aspiration and/or drainage of brain abscesses is considered to be the first-line treatment for abscesses larger than 25 mm. This is ususally performed with the aid of CT-guided stereotaxy. A method of ultrasound guidance is presented that allows a single burr hole approach with real-time imaging of the whole procedure. A bayonet-like shaped ultrasound probe with tip dimension of 8 x 8 mm only (EUP-NS 32, Hitachi/Ecoscan) with frequencies of 3.5 and 5 MHz is used. After placement of a burr hole the target is identified by transdural insonation, a guideline is adjusted and a mounted puncture-adapter guides the cannula towards the lesion under real-time imaging control. Up to now 12 abscesses in 10 patients were treated. Visualization was always excellent. A second aspiration had to be performed twice. One abscess did not contain enough pus to be cured by aspiration and was removed by open surgery, another could not be tapped by the blunt cannula and was aspirated under stereotactic control using a sharp trocar. Outcome was excellent in 6 patients and fair in 2 patients but this was due to the pre-existing disease. Two patients admitted in deep coma died despite an emergency operation. The presented method has proven to be a very powerful guiding tool in the surgical treatment of brain abscesses through a single burr hole approach.     

Number of burr holes as independent predictor of postoperative recurrence in chronic subdural haematoma

Chronic subdural haematoma (cSDH) is one of the most frequent neurosurgical entities. Current treatment options include burr hole craniostomy, twist drill craniostomy or craniotomy. While burr hole craniostomy is the most often used technique, there are no studies analysing the use of one vs. two burr holes in respect to recurrence rates and complications. This retrospective study included 76 (age: 60 +/- 12 years) patients presenting with cSDH admitted in our institution from January 2004 to December 2005. A total of 21 (27%) patients underwent bilateral craniostomy. The patients were assessed using the Markwalder Scale (2 +/- 0.71), Glasgow Coma Scale (14 +/- 1) and measuring the haematoma thickness (1.8 +/- 0.7 cm). The decision to perform one or two burr hole was made according to the personal preference of the treating neurosurgeon. All patients underwent irrigation and placement of closed-system drainage. Out of the 97 haematoma, 63 (65%) haematomas were treated with two burr holes, whereas 34 (35%) were treated with one burr hole. Patients with one burr hole had a statistically significant (p < 0.05) higher recurrence rate (29 vs. 5%), longer average hospitalization length (11 vs. 9 days) and higher wound infection rate (9% vs. 0%). A multivariate regression analysis identified the number of holes as single predictor for postoperative recurrence rate (r(2) = 0.12; p < 0.001). In this study, the treatment of cSDH with one burr hole only is associated with a significantly higher postoperative recurrence rate, longer hospitalization length and higher wound infection rate.     

Chronic subdural haematomas: a comparative study of an enlarged single burr hole versus double burr hole drainage

Various surgical treatments have been proposed for the treatment of chronic subdural haematoma (CSDH). Herewith, we set out to compare the efficacy of an enlarged single burr hole versus double burr hole drainage for the treatment of CSDH. We studied patients with symptomatic CSDH proven by CT scan that were treated in our institute between January 2002 and January 2009. All patients were treated by an enlarged single or double burr hole drainage. A subdural drain was placed in all cases. A total of 245 patients were included in the study. Double hole drainage was performed in 156 (63.7 %) patients (group A) and an enlarged single burr hole drainage in 89 (36.3 %) patients (group B). There were nine recurrences in group A and five in group B; however, the difference was not statistically significant. There was no significant relationship between recurrence rate and age, gender, bilateral haematoma and antiplatelet or anticoagulant therapy. There was a trend towards higher risk of recurrence for patients with residual clots on postoperative CT scan. The mean hospitalization time was 6.2 days, and there was no significant difference between the two groups. No significant difference was found between patients' outcome, as assessed by Glasgow outcome scale score, and treatment method. Enlarged single burr hole and double burr hole drainage had the same efficacy in the treatment of CSDH.     

Ventricular catheter tack-down suture: technical note

Tubing migration accounts for a significant number of shunt complications. In an attempt to reduce the likelihood of disconnection and tubing migration, we have developed a technique to rigidly fix the proximal catheter to the skull. The method involves the placement of a small twist drill hole adjacent to the catheter burr hole through which a suture is passed. The suture is then used to rigidly bind the proximal shunt tubing and valve to the skull. This approach provides an efficient and effective means for reducing complications related to shunt tubing migration.     

Image-guided motor cortex stimulation in patients with central pain.

According to recent clinical data, motor cortex stimulation (MCS) is an alternative treatment for central pain syndromes. We present our minimally invasive technique of image guidance for the placement of the motor cortex-stimulating electrode and assess the clinical usefulness of both neuronavigation and vacuum headrest. Five patients suffering from central pain underwent MCS with the guidance of a frameless stereotactic system (BrainLab AG, Munich, Germany). The neuronavigation was used for identification of the precentral gyrus and accurate planning of the single burr hole. The exact location was reconfirmed by an intraoperative stimulation test. Postoperative clinical and neuroradiological evaluations were performed in each patient. The navigation system worked properly in all 5 neurosurgical cases. Determination of the placement of stimulating electrode was possible in every case. All patients obtained postoperative pain relief. No surgical complication occurred, and the postoperative course was uneventful in all patients. This preliminary experience may confirm image guidance as a useful tool for the surgery of MCS. Additionally, minimal and safe exposure can be achieved using a single burr hole and vacuum headrest.     

A sine-wave-shaped skin incision for inserting deep-brain stimulators

Background

The sine-wave-shaped skin incision is a technique that minimizes skin-related complications near burr hole caps after electrode placement for deep-brain stimulation (DBS).

Methods

Between 2011 and 2013, 54 DBS electrodes were implanted in 27 consecutive patients with Parkinson’s disease (PD), essential tremor, or dystonia. The sine-wave incision was used in 26 patients and conventional bilateral linear scalp incisions were used in one patient.

Results

None of the patients whose operations involved sine-wave-shaped incisions developed hardware-linked complications such as skin infection or skin erosion. The one patient who underwent conventional bilateral linear scalp incisions developed a skin infection.

Conclusion

By preserving the vascular anatomy of the scalp and reducing skin tension at the wound site, the sine-wave-shaped incision promotes wound healing.     

The impact of brain shift in deep brain stimulation surgery: observation and obviation

Background

The impact of brain shift on deep brain stimulation surgery is considerable. In DBS surgery, brain shift is mainly caused by CSF loss. CSF loss can be estimated by post-surgical intracranial air. Different approaches and techniques exist to minimize CSF loss and hence brain shift. The aim of this survey was to investigate the extent and dynamics of CSF loss during DBS surgery, analyze its impact on final electrode position, and describe a simple and inexpensive method of burr hole closure.

Methods

Sixty-six patients being treated with deep brain stimulation were retrospectively analyzed for this treatise. During surgery, CSF loss was minimized using bone wax as a burr hole closure. Intracranial air volume was calculated based on early post-surgery stereotactic 3D CT and correlated with duration of surgery and electrode deviations derived from post-surgery image fusion.

Results

Median early post-surgery intracranial air was 2.1?cm³ (range 0–35.7?cm³, SD 8.53?cm³). No correlation was found between duration of surgery and CSF-loss (R?=?0.078, p?=?0.534), indicating that CSF loss mainly occurs early during surgery. Linear regression analysis revealed no significant correlations regarding volume of intracranial air and electrode displacement in any of the three principal axes. No significant difference regarding electrode deviations between first and second side of surgery were observed.

Conclusions

CSF loss mainly occurs during the early phase of DBS surgery. CSF loss during a later phase of surgery can be effectively averted by burr hole closure. Postoperative intracranial air volumes up to 35?cm³ did not result in significant electrode displacement in our series. Comparing our results to studies previously published on this subject, burr hole closure using bone wax is highly effective.     

Manual occipital ventricular puncture for cerebrospinal fluid shunt surgery: can aiming be standardized?

The manual occipital ventricular puncture is a standard surgical procedure, but specific targeting has not received sufficient attention despite the experience of anatomical disorientation. This study tried to identify an exact site for the ideal trajectory with this method, especially in the sagittal plane, which avoids contact with the choroid plexus that may be the major source of complications. A total of 44 consecutive adult cases undergoing cerebrospinal fluid shunting through the occipital route for hydrocephalus were retrospectively reviewed for the following: correlations between burr hole site, direction of puncture, and location of the ventricular catheter based on postsurgical radiological studies; calculation of the ideal trajectory to place the catheter tip in the anterior horn of the lateral ventricle without contact with the choroid plexus through the standard occipital burr hole. In addition, the relationships between the location of the ventricular structure, the cranial base line connecting the nasion and inion, and the size of the ventricle were evaluated. Incorrect catheter emplacement was found in five cases, which suggested that this procedure using the standard burr hole site and aim point might result in incorrect catheter placement. The ideal external aim points were widely distributed because of the variable heights of ventricular structures from the cranial baseline. No correlation between the locations of the anatomical points and ventricular size was found. The present study could not define a standard external aim point. Tailored preoperative planning of the trajectory is recommended.     

Burr Hole Evacuation of Chronic Subdural Haematomas Followed by Continuous Inflow and Outflow Irrigation

Summary  Chronic subdural haematomas are prone to recollect, increasing the risk of further complications and death. Burr hole evacuation followed by continuous irrigation of a Ringer solution into the remaining subdural cavity, allows remaining blood to be washed out and the brain to re-expand.  This technique was compared with burr hole evacuation either without or with a passive drainage and craniotomy, respectively.  Reformation of haematomas after continuous irrigation occurred in 2,6% (2/77); more than a twelve (32,6%; 15/46) and a nine (23,8%; 5/21) times rate reduction compared to burr hole evacuation without and with passive drainage, respectively. Compared to the craniotomy results, the rate dropped seventeen times (44,4%; 4/9).  Expect from the two rebleedings in 77 haematomas operated on through burr holes followed by irrigation, all patients recovered including nine recurrent haematomas re-operated on by this method.  Recurrent haematomas operated on through burr hole evacuation alone or with insertion of a passive drainage, recollected in 50% (2/4) and 33,3% (2/6). Similar rate after craniotomies was 11,1% (1/9).  Neither infections nor deaths followed burr hole evacuation combined with continuous irrigation, whereas 5,3% (2/38) and 5,9% (1/17) suffered from empyema after burr hole evacuation alone or combined with a passive drainage, respectively. Five (9,1%) of these 55 patients died either from empyemas (three) or rebleedings (two).  Recurrent haematomas evacuated through a craniotomy had no complications from infections.  Compared to other methods, continuous irrigation reduces the need for re-operation significantly by preventing haematoma recurrence and empyema formation. Contrary to other surgical techniques, haematoma recurrence after second time surgery did not occur.     

A simple stereotactic method for frameless deep brain stimulation

BACKGROUND: Deep brain stimulation (DBS) is widely used to treat advanced Parkinson's disease, other movement and psychiatric disorders. DBS implantation requires application of a stereotactic frame throughout a lengthy procedure, making it uncomfortable and tiring. We designed a stereotactic cube to stage the operation, perform frameless microelectrode recording (MER) and fix the DBS. METHODS: The 15-mm cube is implanted in a burr hole using bone cement. It contains 5 parallel trajectories (central + 4 around). It is aligned by stereotactic frame so that central trajectory reaches the target. Frameless MER is performed by attaching a micro-driver to the cube using 2-5 cannulae (4 cm). The DBS is fixed to the cube by a mini-plate and 1 screw. Ninety-six cubes were compared with 43 Bennet spheres (BS). RESULTS: No cube moved compared to 2 (5%) BS (p < 0.05). The final trajectory was central in 64.4% of cubes compared to 47.5% of BS, and the final target was >2 mm out in no cubes compared to 12.5% of BS (p < 0.01). Infection and haemorrhage were observed in 2.5% and 3.3% of cubes, respectively, while 5% of BS developed infection, 5% haemorrhage and 7.5% skin erosion. CONCLUSIONS: This method is simple and effective in staging DBS procedures, performing frameless MER and DBS implantation, fixation and revision.     

Modified One-piece Supraorbital Approach for Orbital Tumors: Widely Preserved Orbital Roof in a Self-fitting Flap

Objectives The one-piece supraorbital approach is a rational approach for the removal of orbital tumors. However, cutting the roof through the orbit is often difficult. We modified the technique to facilitate the osteotomy and improve the cosmetic effect. Design Three burr holes are made: the first, the MacCarty keyhole (burr hole 1), exposes the anterior cranial fossa and orbit; the second is placed above the supraorbital nerve (burr hole 2); and the third on the superior temporal line. Through burr hole 2, a small hole is created on the roof, 10 mm in depth. Next the roof is rongeured through burr hole 1 toward the preexisting small hole. Seamless osteotomies using a diamond-coated threadwire saw and the preexisting four holes are performed. Lastly the flap is removed. On closure, sutures are passed through holes in the cuts made with the threadwire saw, and tied. Results We applied our technique to address orbital tumors in two adult patients. The osteotomies in the roof were easy, and most parts of the roof were repositioned. Conclusions Our modification results in orbital osteotomies with greater preservation of the roof. Because the self-fitting flap does not require the use of fixation devices, the reconstruction is cosmetically satisfactory.     

Ultrasound-based navigation during intracranial burr hole procedures: experience in a series of 100 cases

BACKGROUND: To establish a rational basis for intraoperative ultrasound guidance in neurosurgical procedures via a single burr hole approach based on the experience of one hundred cases. METHODS: The single burr hole approach is carried out using a bayonet-shaped ultrasound transducer with a tip dimension of 8 x 8 mm. The ultrasound probe with a mounted puncture adapter fits a standard burr hole and allows real-time imaging of the ongoing surgical steps.RESULTS: One hundred cases with five indications have been operated on so far: tapping of the ventricular system (46 patients), tapping of intracranial cysts (23 patients), biopsy of intracranial tumors (15 patients), evacuation of intracranial abscesses (9 patients), and evacuation of intracerebral hematomas (7 patients). Depending on their size, the ventricles could be clearly visualized in 34 of 46 patients. In the remaining patients the free margin of the falx served as orientation. Two ventricles could neither be visualized nor entered. Visualization and puncture of intracranial cysts were easy to achieve throughout, as was the case with abscesses. Tumor biopsy was unsuccessful in two patients harboring lymphomas at distances of more than 50 mm from probe to target. Intracerebral hematomas were easily visualized but, due to the presence of clots, aspiration was impossible in two patients. One patient with a giant glioblastoma died the day after the uneventful biopsy due to increased cerebral edema. No other complications occurred.CONCLUSIONS: The presented method of ultrasound-based neuronavigation is an easy-to-use, fast, and safe technique of real-time imaging for free-hand single burr hole procedures.     

Remote cerebellar hemorrhage after single burr hole drainage of chronic subdural hematoma of the elderly

Remote cerebellar hemorrhage is a usual complication after supratentorial craniotomy. Especially, only several cases have been reported regarding the occurrence of remote cerebellar hemorrhage after burr hole drainage for the treatment of chronic subdural hematoma (CSDH). In this paper, we present an elder patient with this rare postoperative complication. A 73-year-old man presented with dysarthria and right hemiparesis. Computed tomography (CT) demonstrated a left chronic subdural hematoma. Hematoma drainage through a single burr hole was perfomed. About 3 hours after the surgery, the patient became restless and presented nausea and dizziness with a relatively large amount of drainage of hematoma. CT revealed resolution of the subdural hematoma and bilateral cerebellar hemorrhage appearing as "zebra sign". Magnetic resonance angiography and 3D-CT angiography showed the normal structure of posterior circulation in both the arterial and venous phases. The remote cerebellar hemorrhage was suspected to have happened as a result of overdrainage of hematoma. Finally, he was discharged without any neurological deficits. Although remote cerebellar hemorrhage after drainage through a burr hole for the treatment of chronic subdural hematoma is a rare complication, it is necessary to be aware of the possibility of such a complication after supratentorial surgery.     

Magnetic resonance imaging and deep brain stimulation

OBJECTIVE: To determine whether cranial magnetic resonance imaging (MRI) is associated with deep brain stimulation (DBS) lead displacement or program interference. METHODS: In vitro and in vivo studies were performed with the Itrel II implantable pulse generator (IPG) (Model 7424; Medtronic, Minneapolis, MN), Medtronic 3387 and 3389 leads, and a 1.5-T GE Horizon LX scanner (General Electric, Milwaukee, WI). In the in vivo study, two MRI volumetric data sets were compared for each of five patients undergoing staged, bilateral, DBS electrode placement in the thalamic or subthalamic nucleus. The data sets were acquired shortly after the initial implantation and during stereotactic planning for the second implantation (1-8 mo between acquisitions). An additional thalamotomy-treated patient was included as a control patient. Volumetric data were analyzed in a blinded manner, using AnalyzeAVW 3.0 software (Biomedical Imaging Resource, Mayo Clinic, Rochester, MN), to determine lead movement. In the in vitro study, the IPG and leads were positioned in the magnetic field in various configurations and were systematically assessed for movement. RESULTS: In vivo, the majority of measured deviations (88%) were within the standard error of measurement (1.4 mm). The maximal measured deviation was 3 mm (2% occurrence). Excellent tremor control with stimulation was demonstrated, which did not change after MRI. In vitro, the DBS leads demonstrated no deflection when introduced into the magnetic field. Similarly, no changes in IPG battery strength, lead impedance, or program settings were observed. CONCLUSION: MRI was not associated with significant DBS electrode movement or changes in clinical responses. Other IPG models and components and MRI scanners should be evaluated, to develop specific guidelines for MRI among individuals with implanted DBS systems.     

Determination of the Keyhole Position in a Lateral Suboccipital Retrosigmoid Approach

Appropriate placement of the keyhole at the transverse and sigmoid sinus (T/S) junction is important for performance of safe and accurate lateral suboccipital craniotomy with minimum bone loss. Here, we report a method for predicting the position of the T/S junction and investigate the relationship between the T/S junction and asterion. The subjects were 88 patients treated surgically via a lateral suboccipital approach. These cases included 78 acoustic neuromas, 4 meningiomas, 1 trigeminal schwannoma, 1 epidermoid cyst, 2 trigeminal neuralgias, and 1 hemifacial spasm. To expose the T/S junction, we usually place the keyhole lateral to asterion by a half diameter of the burr hole. The distance of the T/S junction from asterion was investigated using three-dimensional computed tomography (3DCT) images. We investigated the differences between the actual and predicted positions of the T/S junction based on skull landmarks, and we compared our method with other literature methods. The mean distances were 5.7 mm caudal and 6.6 mm lateral. The difference between the actual and predicted positions was significantly smaller in our approach compared to other methods. Placing the keyhole lateral to a provisional burr hole just caudal to asterion and lateral by half the diameter of the burr hole was useful for exposure of the T/S junction. The best approach is to use preoperative 3DCT, but this may be limited by equipment problems, emergency cases, or allergy to contrast medium. Determination of the appropriate keyhole position with reference to skull landmarks is a universally useful method.     

Single burr hole surgery for acute spontaneous subdural hematoma in the aged: patient reports of three cases

The method of treatment for acute spontaneous subdural hematoma in aged patients is controversial. Three cases of acute spontaneous subdural hematoma in aged patients, treated by single burr hole drainage without irrigation, were reported. The first case, an 80-year-old male was admitted with complaints of headache and stupor without any history of head trauma. CT revealed a left subdural hematoma with mixed density. Intractable facial convulsion occurred three days after admission. Single burr hole drainage was performed to remove the hematoma, and facial convulsion disappeared one week after the surgery. The second case, a 70-year-old male was admitted with complaints of consciousness disturbance without any history of head trauma. CT showed a right subdural hematoma with mixed density. The next day, he recovered consciousness and CT demonstrated shrinkage of the hematoma. However, his consciousness deteriorated again 11 days after admission, and CT revealed progression of the hematoma. We performed single burr hole drainage, and the next day, his neurological condition recovered. The third case, an 84-year-old female was admitted with complaints of consciousness disturbance without any history of head trauma. CT revealed a left subdural hematoma with mixed density. Single burr hole drainage was performed to remove the hematoma. She recovered completely and was discharged and return home 1 month after the surgery. Single burr hole drainage is less invasive than craniotomy. Our three cases indicate that this method may be one of the best methods for aged patients with acute spontaneous subdural hematoma which manifests mixed density in CT.     

Endoscopic approach to colloid cysts.

OBJECTIVE: The aim of this study is to discuss the variations in the morbid anatomy of colloid cysts with its impact on the choice of endoscopic approach through a standard Kocher's burr hole. METHODS: This study was conducted on 18 patients between 1996 and 2006. All patients were operated through a single burr hole at Kocher's point using a rigid endoscope with a single working channel. The anatomical variations of the cyst and the foramen of Monro dictated the use of the transforaminal approach, the transseptal interforniceal approach or both. RESULTS: There were no mortalities or significant morbidities. The operative time ranged between 90 to 240 minutes (with a mean of 133 minutes). Five patients (27.7%) developed remediable postoperative chemical meningitis successfully controlled with steroids. Postoperative transient memory disturbance was observed in 3 patients (16.7%). One patient had a postoperative CSF leak that stopped spontaneously. Aspiration of the cyst's contents showed variable degrees of resistance to aspiration. The period of follow-up ranged between 5 months to 8 years and 3 months (mean: 4 years and 2 months). None of our patients showed radiological evidence of cyst recurrence during the follow-up period. CONCLUSION: Through a single right pre-coronal burr hole at Kocher's point, several endoscopic manoeuvres can be done. These include aspiration of the contents or its piecemeal removal, combined balloon squeeze and aspiration, foraminoplasty, pellucidotomy, coagulation of cyst capsule and ETV. The choice of the appropriate approach is largely dependent on the location of the cyst and the shape of the foramen of Monro. Coronal MRI may aid in preoperative evaluation of the tucked up retroforaminal growth of the cyst. We had no recurrence in our series with a follow-up reaching more than 8 years. This could be attributed to both the marsupialization and coagulation done for the remaining cyst capsule.     

Targeting for thalamic deep brain stimulator implantation without computer guidance: assessment of targeting accuracy

The authors assess the accuracy of targeting nucleus ventralis intermedius (Vim) with fast spin echo inversion recovery (FSE/IR) magnetic resonance imaging (MRI) in 18 successful deep brain stimulator (DBS) implants for medically refractory tremor. FSE/IR-MRI-derived coordinates are compared to the final coordinates employed for DBS lead placement, selected with intraoperative neurophysiology. The authors conclude that FSE/IR MRI is sufficiently reliable to serve as the sole means of anatomically targeting Vim for DBS lead placement. An independent computer workstation is not required for accurate targeting; however, intraoperative neurophysiology remains essential.