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

Abstract

OBJect The authors report different MRI patterns in patients with essential tremor (ET) or obsessive-compulsive disorder (OCD) after transcranial MR-guided focused ultrasound (MRgFUS) and discuss possible causes of occasional MRgFUS failure. MetHODS Between March 2012 and August 2013, MRgFUS was used to perform unilateral thalamotomy in 11 ET patients and bilateral anterior limb capsulotomy in 6 OCD patients; in all patients symptoms were refractory to drug therapy. Sequential MR images were obtained in patients across a 6-month follow-up period. reSultS For OCD patients, lesion size slowly increased and peaked 1 week after treatment, after which lesion size gradually decreased. For ET patients, lesions were visible immediately after treatment and markedly reduced in size as time passed. In 3 ET patients and 1 OCD patient, there was no or little temperature rise (i.e., < 52°C) during MRgFUS. Successful and failed patient groups showed differences in their ratio of cortical-to-bone marrow thickness (i.e., skull density). cOncluSiOnS The authors 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.Clinical trial registration nos. NCT01932463 (for ET) and NCT01986296 (for OCD) (ClinicalTrials.gov) http://thejns.org/doi/abs/10.3171/2014.8.JNS132603Key WOrDS MR-guided focused ultrasound; thalamotomy; capsulotomy; skull density; essential tremor; functional neurosurgery; obsessive-compulsive disorder aBBreViatiOnS ALIC = anterior limb of the internal capsule; ET = essential tremor; MRgFUS = magnetic resonance-guided focused ultrasound; MRI = magnetic resonance imaging; OCD = obsessive-compulsive disorder; Vim = ventral intermediate.

Volumetric analysis of magnetic resonance–guided focused ultrasound thalamotomy lesions

“…2,15,28 This volume change was seen for all 3 zones individually, with the growth of perilesional edema being particularly significant. Interestingly, the edema did not expand equally in all directions.…”

“…In this study, the majority of patients did have discernable lesions at 1 year posttreatment. 2,15 At the 1-year time point, the lesions were either T2 hypointense or T2 hyperintense, likely a lacuna of fluid that remained after the absorption/ breakdown of tissue at the centroid of necrosis. Interestingly, the 1 patient in whom the lesion completely disappeared at the 1-year time point also had the lowest clinical improvement in CRST score.…”

Focused ultrasound–mediated noninvasive blood-brain barrier modulation: preclinical examination of efficacy and safety in various sonication parameters

“…Thermal ablation with high-intensity focused ultrasound (HIFU), in particular, has shown clinical efficacy for the treatment of Parkinson's disease, essential tremor, and obsessive-compulsive disorder. 7,19,20,29 In addition to the ablative uses of FUS, current research has focused on the application of FUS to open the BBB in preclinical therapeutic studies and clinical trials.…”

The use of transcranial focused ultrasound in CNS diseases

“…H. Jung и соавт. [27] не до-стигли результата у 4 из 17 пациентов при ультразвуковой vim-таламотомии и капсулотомии. Предполагается, что ограничения могут быть связаны с большим объемом че-репа над межкомиссуральной линией соотношением тол-щины компактного и губчатого вещества костей черепа, формой черепа и другими факторами.…”

“…Jung и соавт. [27] представили исследование по сравнению очагов при ультразвуковой vim-таламотомии (11 пациентов с эссенциальным тремором) и капсулото-мии (6 пациентов с обсессивно-компульсивными рас-стройствами). При vim-таламотомии очаги были четко видны непосредственно после лечения и явно уменьша-лись со временем, практически исчезая.…”