Successful subthalamic nucleus deep brain stimulation therapy after significant lead displacement from a subdural hematoma

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.

Magnetic resonance-transcranial ultrasound fusion imaging: A novel tool for brain electrode location

BACKGROUND

A combination of preoperative magnetic resonance imaging (MRI) with real-time transcranial ultrasound, known as fusion imaging, may improve postoperative control of deep brain stimulation (DBS) electrode location. Fusion imaging, however, employs a weak magnetic field for tracking the position of the ultrasound transducer and the patient's head. Here we assessed its feasibility, safety, and clinical relevance in patients with DBS.

METHODS

Eighteen imaging sessions were conducted in 15 patients (7 women; aged 52.4 ± 14.4 y) with DBS of subthalamic nucleus (n = 6), globus pallidus interna (n = 5), ventro-intermediate (n = 3), or anterior (n = 1) thalamic nucleus and clinically suspected lead displacement. Minimum distance between DBS generator and magnetic field transmitter was kept at 65 cm. The pre-implantation MRI dataset was loaded into the ultrasound system for the fusion imaging examination. The DBS lead position was rated using validated criteria. Generator DBS parameters and neurological state of patients were monitored.

RESULTS

Magnetic resonance-ultrasound fusion imaging and volume navigation were feasible in all cases and provided with real-time imaging capabilities of DBS lead and its location within the superimposed magnetic resonance images. Of 35 assessed lead locations, 30 were rated optimal, three suboptimal, and two displaced. In two cases, electrodes were re-implanted after confirming their inappropriate location on computed tomography (CT) scan. No influence of fusion imaging on clinical state of patients, or on DBS implantable pulse generator function, was found.

CONCLUSIONS

Magnetic resonance-ultrasound real-time fusion imaging of DBS electrodes is safe with distinct precautions and improves assessment of electrode location. It may lower the need for repeated CT or MRI scans in DBS patients.