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Open access

Feasibility of targeting the cingulate gyrus using high-intensity focused ultrasound on a cadaveric specimen: illustrative case

Francesco Sammartino, James Mossner, Hunter Stecko, Nihaal Reddy, and Brian Dalm

BACKGROUND

Cancer is commonly associated with pain. For patients with advanced cancer and intractable pain, ablative neurosurgical procedures can significantly improve pain and transition patients out of inpatient settings. These procedures are normally invasive, and this poses an important risk in this population. Cingulotomy has been reported to improve pain perception and contribute substantially to the quality of life of cancer patients with refractory pain.

OBSERVATIONS

One fresh human cadaver specimen was used for the setup. The cingulate gyrus was targeted using intraoperative magnetic resonance images, and osseous aberrations were corrected after coregistration with the preoperative head computed tomography.

After accounting for sinuses, membrane folds, and calcifications, a total of 737 elements were available for thermal ultrasound ablation. On high-power sonications, the total energy delivered reached a peak temperature of 57°C (15,050 J, 350 W, 45 seconds) in the right cingulate and 52°C (13,000 J, 405 W, 46 seconds) in the left cingulate.

LESSONS

Despite the limitations of using a cadaver model (temperature, vascularization), cingulotomy appears to be feasible using high-intensity focused ultrasound.

https://thejns.org/doi/10.3171/CASE2459

Open access

Stereo electroencephalography–guided radiofrequency ablation in focal epilepsia partialis continua: illustrative case

Mikael Levy, Nir Getter, Moshe Zer-Zion, Alexie Mirson, Fidda Abu Arisheh, Ahmad Kilani, Sandy Madar, Mordechai Lorberboym, Frida Shemesh, and Jehuda Sepkuty

BACKGROUND

Epilepsia partialis continua (EPC) is a variant of focal motor status epilepticus that can occur as a single or repetitive episode with progressive or nonprogressive characteristics.

OBSERVATIONS

The authors describe the feasibility of identifying focal EPC in a 33-year-old woman using video electroencephalography (VEEG), electroencephalography source localization, [18F]fluorodeoxyglucose positron emission tomography, magnetic resonance imaging, and psychiatric and neuropsychological assessments and of treating it with stereo electroencephalography–guided radiofrequency (SEEG-RF) ablation. EPC comprised recurrent myoclonus of the right thigh and iliopsoas with a progressive pain syndrome after left anterior-temporo-mesial resection. Switching between VEEG under regular and epidural block helped to define myoclonus as the presenting ictal symptom with a suspected seizure onset zone in the left parietal paramedian lobule. After the epileptic network was identified, SEEG-RF ablation abolished all seizures. No correlation was found between pain and VEEG/SEEG abnormalities. Rehabilitation began 3 days after the SEEG-RF ablation. By 1 year of follow-up, the patient had no EPC and could walk with assistance in rehabilitation; however, due to the abrupt abolishment of EPC and underlying psychological factors, the patient perceived her pain as overriding, which prevented her from walking.

LESSONS

The application of SEEG-RF ablation is an efficient therapeutic option for focal EPC with special concerns regarding concurrent nonepileptic pain.

https://thejns.org/doi/10.3171/CASE23611

Open access

Magnetic resonance imaging–guided focused ultrasound thalamotomy for essential tremor in a patient with von Willebrand disease: perioperative optimization for patients with coagulopathies. Illustrative case

Caroline Folz, Andreas Seas, Fadzai Chinyengetere, Christopher Beasley, Adam Harris, Charity Oyedeji, Thomas L Ortel, Bhavya R Shah, Shivanand Lad, and Stephen C Harward

BACKGROUND

Essential tremor (ET) is one of the most common movement disorders worldwide. In medically refractory ET, deep brain stimulation (DBS) of the ventral intermediate nucleus of the thalamus is the current standard of care. However, DBS carries an inherent 2% to 3% risk of hemorrhage, a risk that can be much higher in patients with concomitant coagulopathy. Magnetic resonance imaging–guided focused ultrasound (MRgFUS) thalamotomy is a surgical alternative that is highly effective in treating ET, with no reports of intracranial hemorrhage to date.

OBSERVATIONS

This is the first documented case of successful MRgFUS thalamotomy in a patient with von Willebrand disease (VWD). A 60-year-old left-handed male had medically refractory ET, VWD type 2B, and a family history of clinically significant hemorrhage after DBS. He underwent right-sided MRgFUS thalamotomy and received a perioperative course of VONVENDI (recombinant von Willebrand factor) to ensure appropriate hemostasis. Postprocedure imaging confirmed a focal lesion in the right thalamus without evidence of hemorrhage. The patient reported 90% improvement of his left-hand tremor and significant improvement in his quality of life without obvious side effects.

LESSONS

MRgFUS thalamotomy with peri- and postoperative hematological management is a promising alternative to DBS for patients with underlying coagulopathies.

Open access

Arachnoid bands in hemifacial spasm: an overlooked etiology? Illustrative case

Mariam Al-Mutawa and Henry W. S Schroeder

BACKGROUND

Primary hemifacial spasm (HFS) is usually caused by arterial compression of the facial nerve at the root exit zone at the brainstem. Rarely, a purely venous compression is seen. However, arachnoid bands strangulating the facial nerve have not been recognized as a cause of hemifacial spasm.

OBSERVATIONS

The authors present a case of a 24-year-old female who had experienced HFS for 9 years. Endoscopic inspection of the root exit zone revealed no vascular compression but an arachnoid band strangulating the facial nerve. After cutting the band, the lateral spread response disappeared, and the patient was immediately spasm free after the surgery. Two years later, she was still doing well without any spasms.

LESSONS

This is the third patient in the authors’ series of 535 patients who had no vascular conflict but rather a strangulation of the nerve by arachnoid bands. All patients have remained spasm free. To the authors’ knowledge, no other group has reported arachnoid bands as an etiological factor of HFS so far.

Open access

Intraoperative application of indocyanine green and temporary venous occlusion test to assess collateral flow during microvascular decompression for venous-related trigeminal neuralgia: illustrative case

Kentaro Fujimoto, Yosuke Akamatsu, Yasumasa Nishikawa, and Kuniaki Ogasawara

BACKGROUND

In microvascular decompression (MVD) for vein-related trigeminal neuralgia (TN), determining whether transection of the offending vein is safe can be challenging. Here, the authors present a case of vein-related TN successfully treated by sacrificing the offending vein on the basis of findings from indocyanine green (ICG) video angiography and a temporary venous occlusion test to assess the collateral flow of the offending vessel.

OBSERVATIONS

A 43-year-old man presented with TN, which had failed to respond to previous medical therapy. Gadolinium-enhanced magnetic resonance imaging (MRI) revealed that the transverse or superior petrosal vein was the offending vein. The patient underwent MVD. Because the transposition of the offending vein was anatomically challenging, a temporary vein occlusion test was performed using ICG video angiography. During and after temporary occlusion, bidirectional flow in the offending vein was observed, suggesting collateral flow even after vein occlusion. On the basis of these findings, the offending vein was transected, resulting in relief from pain without any complications. Postoperative MRI revealed no new lesions in the brainstem or the cerebellar hemisphere. The patient has been free from neuralgia for 6 months.

LESSONS

The temporary vein occlusion test under ICG video angiography was useful for evaluating collateral flow in the offending vein in TN.

Open access

Cervicothoracic ventral-dorsal rhizotomy for bilateral upper-extremity hypertonia in cerebral palsy: illustrative case

Ryan Kelly, Hanna R Kemeny, Sunny Abdelmageed, Robin Trierweiler, Tim Krater, Melissa A LoPresti, and Jeffrey S Raskin

BACKGROUND

Management of medically refractory limb-specific hypertonia is challenging. Neurosurgical options include deep brain stimulation, intrathecal baclofen, thalamotomy, pallidotomy, or rhizotomy. Cervical dorsal rhizotomy has been successful in the treatment of upper-extremity spasticity. Cervical ventral and cervical ventral-dorsal rhizotomy (VDR) has been used in the treatment or torticollis and traumatic hypertonia; however, the use of cervicothoracic VDR for the treatment of upper-extremity mixed hypertonia is not well described.

OBSERVATIONS

A 9-year-old girl with severe quadriplegic mixed hypertonia secondary to cerebral palsy (CP) underwent cervicothoracic VDR. Modified Ashworth Scale scores, provision of caregiving, and examination improved. Treatment was well tolerated.

LESSONS

Cervicothoracic VDR can afford symptomatic and quality of life improvement in patients with medically refractory limb hypertonia. Intraoperative positioning and nuances in surgical techniques are particularly important based on spinal cord position as modified by scoliosis. Here, the first successful use of cervicothoracic VDR for the treatment of medically refractory upper-limb hypertonia in a pediatric patient with CP is described.

Open access

Quantitative susceptibility mapping and a nonlinearly transformed atlas for targeting the ventral intermediate nucleus of the thalamus in a patient with tremor and thalamic hypertrophy: illustrative case

Kazuya Ohtsuki, Masahiro Sawada, Wataru Yoshizaki, Takayoshi Ishimori, Nobukatsu Sawamoto, Yasutaka Fushimi, and Hiroki Toda

BACKGROUND

The ventral intermediate nucleus (Vim) of the thalamus is a surgical target for treating various types of tremor. Because it is difficult to visualize the Vim using standard magnetic resonance imaging, the structure is usually targeted based on the anterior and posterior commissures. This standard targeting method is practical in most patients but not in those with thalamic asymmetry. The authors examined the usefulness of quantitative susceptibility mapping (QSM) and transformed Vim atlas images to estimate the Vim localization in a patient with tremor and significant thalamic hypertrophy.

OBSERVATIONS

A 51-year-old right-handed female had experienced a predominant left-hand action tremor for 6 years. Magnetic resonance imaging showed significant hypertrophy of the right thalamus and caudal shift of the thalamic ventral border. The authors referred to the QSM images to localize the decreased susceptibility area within the lateral ventral thalamic nuclei to target the Vim. In addition, the nonlinearly transformed Vim atlas images complemented the imaging-based targeting. The radiofrequency thalamotomy at the modified Vim target relieved the tremor completely.

LESSONS

A combination of QSM and nonlinear transformation of the thalamic atlas can be helpful in the targeting method of the Vim for tremor patients with thalamic asymmetry.

Open access

Optimization of direct cortical stimulation using tibial versus median nerve sensory mapping during midline brain tumor resection: illustrative case

Denmark Mugutso, Charles Warnecke, Lee Eric Tessler, Christopher J Pace, and Marat V Avshalumov

BACKGROUND

During brain tumor resection, neurophysiological mapping and monitoring help surgeons locate, characterize, and functionally assess eloquent brain areas in real time. The selection of mapping and monitoring targets has implications for successful surgery. Here, the authors compare direct cortical stimulation (DCS) as suggested by median nerve (MN) with posterior tibial nerve (PTN) cortical sensory mapping (SM) during mesial lesion resection.

OBSERVATIONS

Recordings from a 6-contact cortical strip served to generate an MN and a PTN sensory map, which indicated the strip was anterior to the central sulcus. Responses exhibited an amplitude gradient with no phase reversal (PR). DCS, elicited through a stimulus probe or contact(s) of the strip, yielded larger responses from the corresponding sensory mapped limb; that is, PTN SM resulted in larger lower limb muscle responses than those suggested by MN SM.

LESSONS

SM of the MN and PTN is effective for localizing eloquent cortical areas wherein the PTN is favored in surgery for mesial cortical tumors. The recorded amplitude of the cortical somatosensory evoked potential is a valuable criterion for defining the optimal location for DCS, despite an absent PR. The pathway at risk dictates the specifics of SM, which subsequently defines the optimal location for DCS.

Open access

Vagus nerve stimulation for enhanced stroke recovery after intracerebral hemorrhage: illustrative case

Daniel D Cummins, Roshini Kalagara, Margaret H Downes, Hyun Joo Park, Jenna Tosto-Mancuso, David Putrino, Fedor E Panov, and Christopher P Kellner

BACKGROUND

Randomized controlled trial (RCT) evidence has revealed the efficacy of vagus nerve stimulation (VNS) paired with rehabilitation therapy, over therapy alone, for upper-limb functional recovery after ischemic stroke. However, this technique has not yet been described for the recovery of chronic motor deficits after hemorrhagic stroke.

OBSERVATIONS

Three years after left putaminal intracerebral hemorrhagic stroke with chronic upper-limb functional deficits, a patient was treated with VNS for enhanced stroke recovery. VNS was paired with 6 weeks of in-clinic physical therapy, resulting in upper-limb functional improvement of 14 points on the Fugl-Meyer Assessment Upper Extremity (FMA-UE) index for stroke recovery (maximum score of 66 equating to normal function). This improvement was more than 1 standard deviation above the improvement documented in the first successful RCT of VNS paired with therapy for ischemic stroke (5.0 ± 4.4 improvement on FMA-UE).

LESSONS

VNS is a promising therapy for enhanced recovery after hemorrhagic stroke and may offer greater improvement in function compared to that after ischemic stroke. Improvement in function can occur years after the time of intracerebral hemorrhage.

Open access

Microvascular decompression for developmental venous anomaly causing hemifacial spasm: illustrative case

Margaret Tugend and Raymond F Sekula Jr.

BACKGROUND

Developmental venous anomaly (DVA) is a rare cause of hemifacial spasm (HFS). The treatment of HFS caused by a DVA varies in the literature and includes medication management, botulinum toxin injections, and microvascular decompression (MVD).

OBSERVATIONS

A 64-year-old woman presented with right-sided HFS. Preoperative magnetic resonance imaging showed a DVA in the right inferior pons, with an enlarged segment compressing the facial nerve at its root detachment point prior to drainage into the superior petrosal sinus. MVD was performed, and the facial nerve was decompressed without sacrifice of the vein. Immediately following the procedure, the patient had significantly reduced spasms. The patient became spasm-free 3 months after MVD and maintained spasm freedom for 3 months. Six months after MVD, the patient had a partial return of spasms. At 8 months, the patient continued to have reduced and intermittent spasms in the right orbicularis oculi muscle.

LESSONS

MVD for HFS caused by a DVA is a safe procedure and can be effective at reducing spasm frequency and severity.