Magnetic resonance guided focused ultrasound thalamotomy for essential tremor

Magnetic resonance guided focused ultrasound thalamotomy for essential tremor

Magnetic resonance guided focused ultrasound is a minimally invasive surgical procedure for symptomatic treatment of Parkinson Disease. With this technology, the ventral intermediate nucleusSTN, and internal globus pallidus have been targeted for therapeutic cerebral ablation, while also minimizing the risk of hemorrhage and infection from more invasive neurosurgical procedures.

In a pilot study published in 2013, essential tremor improved in 15 patients treated with magnetic resonance guided focused ultrasound thalamotomy1).

Clinical trials have confirmed the efficacy of focused ultrasound (FUS) thalamotomy in essential tremor, but its effectiveness and safety for managing tremor-dominant Parkinson disease (TDPD) is unknown.

It might change the way that patients with essential tremor and potentially other disorders are treated 2).

Effectiveness

The post-treatment effectiveness was evaluated using the clinical rating scale for tremors. Thalamic MRgHIFU had substantial therapeutic effects on patients, based on MRgHIFU-mediated improvements in movement control and significant changes in brain mu rhythms. Ultrasonic thalamotomy may reduce hyper-excitable activity in the motor cortex, resulting in normalized behavioral activity after sonication treatment. Thus, non-invasive and spatially accurate MRgHIFU technology can serve as a potent therapeutic tool with broad clinical applications 3).

Safety

Magnetic resonance guided focused ultrasound (MRgFUS) for thalamotomy is a safe, effective and less-invasive surgical method for treating medication-refractory essential tremor (ET). However, several issues must be resolved before clinical application of MRgFUS, including optimal patient selection and management of patients during treatment 4).

Jung et al. found different MRI pattern evolution after MRgFUS for white matter and gray matter. Their results suggest that skull characteristics, such as low skull density, should be evaluated prior to MRgFUS to successfully achieve thermal rise 5).

Nursing management

In a large academic medical center in the mid-Atlantic region, the Department of Neurosurgery conducted a continued access study, recently approved by the Food and Drug Administration, to evaluate the effectiveness of transcranial FUS thalamotomy for the treatment of medication-refractory ET.

One patient’s experience will be introduced, including discussion of evidence-based treatment options for ET and information on the nursing management of the patient undergoing FUS thalamotomy 6).

Prospective randomized clinical trials

In a double-blinded, prospective, sham-controlled randomized controlled trial of MR-guided focused ultrasound thalamotomy for treatment of tremor-dominant PD, 62% of treated patients demonstrated improvement in tremor scores from baseline to 3 months postoperatively, as compared to 22% in the sham group. There has been only one open-label trial of MR-guided focused ultrasound subthalamotomy for patients with PD, demonstrating improvements of 71% for rigidity, 36% for akinesia, and 77% for tremor 6 months after treatment. Among the two open-label trials of MR-guided focused ultrasound pallidotomy for patients with PD, dyskinesia and overall motor scores improved up to 52% and 45% at 6 months postoperatively. Although MR-guided focused ultrasound thalamotomy is now approved by the U.S. Food and Drug Administration for treatment of parkinsonian tremor, additional high-quality randomized controlled trials are warranted and are underway to determine the safety and efficacy of MR-guided focused ultrasound subthalamotomy and pallidotomy for treatment of the cardinal features of PD. These studies will be paramount to aid clinicians to determine the ideal ablative target for individual patients. Additional work will be required to assess the durability of MR-guided focused ultrasound lesions, ideal timing of MR-guided focused ultrasound ablation in the course of PD, and the safety of performing bilateral lesions 7).

Case series

References

1)

Elias WJ, Huss D, Voss T, Loomba J, Khaled M, Zadicario E, Frysinger RC, Sperling SA, Wylie S, Monteith SJ, Druzgal J, Shah BB, Harrison M, Wintermark M. A pilot study of focused ultrasound thalamotomy for essential tremor. N Engl J Med. 2013 Aug 15;369(7):640-8. doi: 10.1056/NEJMoa1300962. PubMed PMID: 23944301.
2)

Lipsman N, Schwartz ML, Huang Y, Lee L, Sankar T, Chapman M, Hynynen K, Lozano AM. MR-guided focused ultrasound thalamotomy for essential tremor: a proof-of-concept study. Lancet Neurol. 2013 May;12(5):462-8. doi: 10.1016/S1474-4422(13)70048-6. Epub 2013 Mar 21. PubMed PMID: 23523144.
3)

Chang JW, Min BK, Kim BS, Chang WS, Lee YH. Neurophysiologic correlates of sonication treatment in patients with essential tremor. Ultrasound Med Biol. 2015 Jan;41(1):124-31. doi: 10.1016/j.ultrasmedbio.2014.08.008. Epub 2014 Oct 22. PubMed PMID: 25438838.
4)

Chang WS, Jung HH, Kweon EJ, Zadicario E, Rachmilevitch I, Chang JW. Unilateral magnetic resonance guided focused ultrasound thalamotomy for essential tremor: practices and clinicoradiological outcomes. J Neurol Neurosurg Psychiatry. 2015 Mar;86(3):257-64. doi: 10.1136/jnnp-2014-307642. Epub 2014 May 29. PubMed PMID: 24876191.
5)

Jung HH, Chang WS, Rachmilevitch I, Tlusty T, Zadicario E, Chang JW. Different magnetic resonance imaging patterns after transcranial magnetic resonance-guided focused ultrasound of the ventral intermediate nucleus of the thalamus and anterior limb of the internal capsule in patients with essential tremor or obsessive-compulsive disorder. J Neurosurg. 2015 Jan;122(1):162-8. doi: 10.3171/2014.8.JNS132603. PubMed PMID: 25343176.
6)

Shaw KD, Johnston AS, Rush-Evans S, Prather S, Maynard K. Nursing Management of the Patient Undergoing Focused Ultrasound: A New Treatment Option for Essential Tremor. J Neurosci Nurs. 2017 Aug 16. doi: 10.1097/JNN.0000000000000301. [Epub ahead of print] PubMed PMID: 28817495.
7)

Moosa S, Martínez-Fernández R, Elias WJ, Del Alamo M, Eisenberg HM, Fishman PS. The role of high-intensity focused ultrasound as a symptomatic treatment for Parkinson’s disease. Mov Disord. 2019 Jul 10. doi: 10.1002/mds.27779. [Epub ahead of print] Review. PubMed PMID: 31291491.

Textbook of Focused Neurosurgery

Textbook of Focused Neurosurgery
By Cohen Inbar

Textbook of Focused Neurosurgery

List Price: $218.00
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This book is a comprehensive guide to neurosurgery, covering the complete field, from basic and clinical knowledge, to neurosurgical procedures. Beginning with an introduction to neuroanatomy and neurophysiology, the following chapters provide detail on neurological phenomena including altered consciousness, neuro-ophthalmology, neurotology and neurourology. Two sections then discuss cortical malformation, leading onto paediatric neurosurgery. The following chapters provide in depth discussion on essential neuroradiology, then neurosurgical techniques for a range of disorders and injuries, including tumours, seizures, head and spinal trauma, vascular malformations, and stroke. This practice book is highly illustrated with clinical photographs, diagrams and tables. Key Points * Comprehensive guide to neurosurgery, from basics knowledge to surgical procedures * Provides overview of neuroanatomy, neurophysiology and various neurological phenomena * Covers neurosurgical techniques for numerous disorders and injuries * Highly illustrated with clinical photographs, diagrams and tables


Product Details

  • Published on: 2016-08-15
  • Original language: English
  • Binding: Hardcover
  • 550 pages

Editorial Reviews

About the Author
Cohen Inbar MD PhD Attending Neurosurgeon, Department of Neurosurgery, Rambam Health Care Campus, Haifa, Israel; Visiting Professor, Surgical Neuro-Oncology and Radiosurgery, University of Virginia Health Care System, USA

Update: Magnetic resonance guided focused ultrasound thalamotomy for essential tremor

Magnetic resonance guided focused ultrasound thalamotomy for essential tremor

J.Sales-Llopis
Neurosurgery Department, University General Hospital of Alicante, Foundation for the Promotion of Health and Biomedical Research in the Valencian Region (FISABIO), Alicante, Spain

Effectiveness

The post-treatment effectiveness was evaluated using the clinical rating scale for tremors. Thalamic MRgHIFU had substantial therapeutic effects on patients, based on MRgHIFU-mediated improvements in movement control and significant changes in brain mu rhythms. Ultrasonic thalamotomy may reduce hyper-excitable activity in the motor cortex, resulting in normalized behavioral activity after sonication treatment. Thus, non-invasive and spatially accurate MRgHIFU technology can serve as a potent therapeutic tool with broad clinical applications 1).

Safety

Magnetic resonance guided focused ultrasound (MRgFUS) for thalamotomy is a safe, effective and less-invasive surgical method for treating medication-refractory essential tremor (ET). However, several issues must be resolved before clinical application of MRgFUS, including optimal patient selection and management of patients during treatment 2).
Jung et al. found different MRI pattern evolution after MRgFUS for white matter and gray matter. Their results suggest that skull characteristics, such as low skull density, should be evaluated prior to MRgFUS to successfully achieve thermal rise 3).

2014

With institutional review board approval, and with prospective informed consent, 15 patients with medication-refractory essential tremor were enrolled in a Health Insurance Portability and Accountability Act (HIPAA)-compliant pilot study and were treated with transcranial MR imaging-guided focused ultrasound surgery targeting the ventralis intermedius nucleus of the thalamus contralateral to their dominant hand. Fourteen patients were ultimately included.  Diffusion tensor imaging (DTI) (DT MR imaging) studies at 3 Tesla were performed preoperatively and 24 hours, 1 week, 1 month, and 3 months after the procedure. Fractional anisotropy (FA) maps were calculated from the DT imaging data sets for all time points in all patients. Voxels where FA consistently decreased over time were identified, and FA change in these voxels was correlated with clinical changes in tremor over the same period by using Pearson correlation.
Ipsilateral brain structures that showed prespecified negative correlation values of FA over time of -0.5 or less included the pre- and postcentral subcortical white matter in the hand knob area; the region of the corticospinal tract in the semioval center, in the posterior limb of the internal capsule, and in the cerebral peduncle; the thalamus; the region of the red nucleus; the location of the central tegmental tract; and the region of the inferior olive. The contralateral middle cerebellar peduncle and bilateral portions of the superior vermis also showed persistent decrease in FA over time. There was strong correlation between decrease in FA and clinical improvement in hand tremor 3 months after lesion inducement (P < .001).
DT MR imaging after MR imaging-guided focused ultrasound thalamotomy depicts changes in specific brain structures. The magnitude of the DT imaging changes after thalamic lesion inducement correlates with the degree of clinical improvement in essential tremor 4).

2013

If larger trials validate the safety and ascertain the efficacy and durability of this new approach, it might change the way that patients with essential tremor and potentially other disorders are treated 5).


In a pilot study, essential tremor improved in 15 patients treated with MRI-guided focused ultrasound thalamotomy. Large, randomized controlled trials will be required to assess the procedure’s efficacy and safety. (Funded by the Focused Ultrasound Surgery Foundation; ClinicalTrials.gov number, NCT01304758.) 6).


MR examinations were performed before and 2 days after the ultrasound functional neurosurgical treatment to visualize the targets on T2-weighted images and determine their coordinates. Thirty consecutive targets were reconstructed: 18 were in the central lateral nucleus of the medial thalamus (central lateral thalamotomies against neurogenic pain), 1 in the centrum medianum thalamic nucleus (centrum medianum thalamotomy against essential tremor), 10 on the pallido-thalamic tract (pallido-thalamic tractotomies against Parkinson’s disease), and 1 on the cerebello-thalamic tract (cerebello-thalamic tractotomy against essential tremor). We describe a method for reconstruction of the lesion coordinates on post-treatment MR images, which were compared with the desired atlas target coordinates. We also calculated the accuracy of the intra-operative target placement, thus allowing to determine the global, planning, and device accuracies. We also estimated the target lesion volume.
Moser et al. found mean absolute global targeting accuracies of 0.44 mm for the medio-lateral dimension (standard deviation 0.35 mm), 0.38 mm for the antero-posterior dimension (standard deviation 0.33 mm), and 0.66 mm for the dorso-ventral dimension (standard deviation 0.37 mm). Out of the 90 measured coordinates, 83 (92.2%) were inside the millimeter domain. The mean three-dimensional (3D) global accuracy was 0.99 mm (standard deviation 0.39 mm). The mean target volumes, reconstructed from surface measurements on 3D T1 series, were 68.5 mm(3) (standard deviation 39.7 mm(3)), and 68.9 mm(3) (standard deviation 40 mm(3)) using an ellipsoidal approximation 7).

References

1) Chang JW, Min BK, Kim BS, Chang WS, Lee YH. Neurophysiologic correlates of sonication treatment in patients with essential tremor. Ultrasound Med Biol. 2015 Jan;41(1):124-31. doi: 10.1016/j.ultrasmedbio.2014.08.008. Epub 2014 Oct 22. PubMed PMID: 25438838.
2) Chang WS, Jung HH, Kweon EJ, Zadicario E, Rachmilevitch I, Chang JW. Unilateral magnetic resonance guided focused ultrasound thalamotomy for essential tremor: practices and clinicoradiological outcomes. J Neurol Neurosurg Psychiatry. 2015 Mar;86(3):257-64. doi: 10.1136/jnnp-2014-307642. Epub 2014 May 29. PubMed PMID: 24876191.
3) Jung HH, Chang WS, Rachmilevitch I, Tlusty T, Zadicario E, Chang JW. Different magnetic resonance imaging patterns after transcranial magnetic resonance-guided focused ultrasound of the ventral intermediate nucleus of the thalamus and anterior limb of the internal capsule in patients with essential tremor or obsessive-compulsive disorder. J Neurosurg. 2015 Jan;122(1):162-8. doi: 10.3171/2014.8.JNS132603. PubMed PMID: 25343176.
4) Wintermark M, Huss DS, Shah BB, Tustison N, Druzgal TJ, Kassell N, Elias WJ. Thalamic connectivity in patients with essential tremor treated with MR imaging-guided focused ultrasound: in vivo fiber tracking by using diffusion-tensor MR imaging. Radiology. 2014 Jul;272(1):202-9. doi: 10.1148/radiol.14132112. Epub 2014 Mar 9. PubMed PMID: 24620914.
5) Lipsman N, Schwartz ML, Huang Y, Lee L, Sankar T, Chapman M, Hynynen K, Lozano AM. MR-guided focused ultrasound thalamotomy for essential tremor: a proof-of-concept study. Lancet Neurol. 2013 May;12(5):462-8. doi: 10.1016/S1474-4422(13)70048-6. Epub 2013 Mar 21. PubMed PMID: 23523144.
6) Elias WJ, Huss D, Voss T, Loomba J, Khaled M, Zadicario E, Frysinger RC, Sperling SA, Wylie S, Monteith SJ, Druzgal J, Shah BB, Harrison M, Wintermark M. A pilot study of focused ultrasound thalamotomy for essential tremor. N Engl J Med. 2013 Aug 15;369(7):640-8. doi: 10.1056/NEJMoa1300962. PubMed PMID: 23944301.
7) Moser D, Zadicario E, Schiff G, Jeanmonod D. MR-guided focused ultrasound technique in functional neurosurgery: targeting accuracy. J Ther Ultrasound. 2013 Apr 25;1:3. doi: 10.1186/2050-5736-1-3. eCollection 2013. Erratum in: J Ther Ultrasound. 2013;1:17. PubMed PMID: 24761224; PubMed Central PMCID: PMC3988613.
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