Efficacy of Spinal Cord Stimulation Using Differential Target Multiplexed Stimulation for Intractable Pain of Hereditary Neuropathy with Liability to Pressure Palsies: A Case Report.

Hereditary neuropathy with liability to pressure palsies is an extremely rare genetic disorder; it is an autosomal dominant disorder with a high incidence of neuropathic and/or musculoskeletal pain. A case of achieving pain relief by spinal cord stimulation using differential target multiplexed stimulation for a 44-year-old female patient with hereditary neuropathy with liability to pressure palsies who was experiencing severe pain in her back, face, and all four limbs is presented. In her early teens, the initial symptoms were numbness and weakness of a limb after movement, which improved spontaneously. Transient pain in her back followed by systemic and persistent muscle weakness and pain developed. Deletion of the gene for peripheral myelin protein 22 was detected by peripheral nerve biopsy. The diagnosis of hereditary neuropathy with liability to pressure palsies was made in her early thirties. A spinal cord stimulation trial was performed because her severe pain continued despite administering many medications. Therefore, two spinal cord stimulation systems were implanted at the C3-5 and Th8-9 levels by two procedures. Pain in her back, arms, and legs decreased from 8 to 1, 5 to 1, and 6 to 2 on the numerical rating scale, respectively. Furthermore, opioid usage was tapered. The pain of hereditary neuropathy with liability to pressure palsies has a complicated pathogenesis and is resistant to pharmacological treatment. Spinal cord stimulation using differential target multiplexed stimulation may be a viable treatment option.

Radiographic Prediction of the Occipito-C2 Angle Variation with Changes in Distance between the Mandible and Cervical Vertebrae: A Preliminary Study.

The Occipito (O) -C2 angle reflects the correct craniocervical spine alignment; however, the poor image quality of standard intraoperative fluoroscopy at times lead to inaccurate measurements. Herein, we preliminarily investigated the relationship between the O-C2 angle and the Gonion-C2 distance, which is based on the positioning of the mandible and the cervical spine. We enrolled patients who underwent cervical spine radiography in neutral, flexion, and extension positions from January 2020 to October 2020. The difference by posture changes for each parameter was defined as the Δ value, and the Spearman's rank correlation coefficient was determined. Furthermore, we determined the cutoff value of the ΔGonion-C2 distance to predict a decrease of > 10° in the ΔO-C2 angle, which is reported to be related to dysphagia and dyspnea. Seventy-four patients were included. Spearman's rank correlations for the neutral, flexion, and extension positions were 0.630 (P < 0.001), 0.471 (P < 0.001), and 0.625 (P < 0.001), respectively, while the cutoff values of the ΔGonion-C2 distance for predicting > 10° in the ΔO-C2 angle were 9.3 mm for the neutral flexion change (sensitivity: 0.435, specificity: 0.882) and 8.3 mm for the extension-neutral change (sensitivity: 0.712, specificity: 0.909). The O-C2 angle and Gonion-C2 distances correlated; however, this correlation was weaker in the flexed position. Nevertheless, the ΔGonion-C2 distance can be used as a warning sign for postoperative complications after posterior occipital bone fusion surgery, because a decrease of > 10° in the ΔO-C2 angle can be predicted with high specificity.

Pineal parenchymal tumor of intermediate differentiation with late spinal dissemination 13 years after initial surgery: illustrative case.

BACKGROUND: Pineal parenchymal tumors of intermediate differentiation (PPTIDs) are rare in the pineal gland. A case of PPTID that disseminated to the lumbosacral spine 13 years after the total resection of a primary intracranial tumor has been reported. OBSERVATIONS: A 14-year-old female presented with headache and diplopia. Magnetic resonance imaging revealed a pineal tumor that induced obstructive hydrocephalus. A biopsy and endoscopic third ventriculostomy were performed. Histological diagnosis revealed a grade II PPTID. Two months later, the tumor was removed via craniotomy because the postoperative Gamma Knife surgery was ineffective. Histological diagnosis confirmed PPTID, although the grade was revised from II to III. Postoperative adjuvant therapy was not performed, because the lesion had been irradiated and gross total tumor removal was achieved. She has had no recurrence in 13 years. However, pain around the anus newly appeared. Magnetic resonance imaging of the spine revealed a solid lesion in the lumbosacral spine. The lesion was subtotally resected, and histological diagnosis revealed grade III PPTID. Postoperative radiotherapy was performed, and she had no recurrence 1 year after radiotherapy. LESSONS: Remote dissemination of PPTID can occur several years after the initial resection. Regular follow-up imaging, including the spinal region, should be encouraged.

Spinal Cord Stimulation for Neuropathic Pain following a Spinal Cord Lesion with Past Spinal Surgical Histories Using a Paddle Lead Placed on the Rostral Side of the Lesion: Report of Three Cases.

Spinal cord parenchymal lesions may induce intractable neuropathic pain. However, the efficacy of conventional spinal cord stimulation for the neuropathic pain following spinal cord lesions remains to be controversial. In this study, we present three cases of spinal cord stimulation using a paddle lead at the rostral side of the spinal lesion causing pain symptoms. Good pain reductions were achieved using conventional stimulation in one case and using differential target multiplexed stimulation in two cases. Case 1: A 55-year-old man presented with neuropathic pain affecting his bilateral upper extremities due to a traumatic cervical spinal cord injury. Conventional stimulation via a paddle-type electrode was able to reduce the pain from 8 to 4 via a visual analog scale. Case 2: A 67-year-old man had undergone three spinal surgeries. He presented with pain and numbness of bilateral lower extremities due to a spinal cord lesion by thoracic disc herniation. Differential target multiplexed stimulation via a paddle-type electrode achieved excellent pain reduction, that is, from 9 to 2 on the visual analog scale. Case 3: An 80-year-old man presented with pain in his bilateral upper extremities due to a cervical spinal cord lesion caused by compression and spinal canal stenosis. Posterior cervical decompression and paddle-type electrode placement were performed simultaneously. Differential target multiplexed stimulation was able to achieve excellent pain reduction, from 7 to 2 on the visual analog scale. Spinal cord stimulation using a paddle lead at the rostral side of the spinal lesion and differential target multiplexed stimulation may provide significant opportunities for patients with intractable neuropathic pain following spinal cord lesions.

Unilateral laminotomy for bilateral decompression and balloon kyphoplasty to decompress lumber canal stenosis aggravated by osteoporotic vertebral compression fractures: A technical note.

Background: The optimal treatment of lumbar canal stenosis (LCS) associated with osteoporotic vertebral fractures (OVFs) remains unclear. Here, we have combined a minimally invasive unilateral laminotomy for bilateral decompression (ULBD) alone with balloon kyphoplasty (BKP) for LCS aggravated by OVF. Methods: ULBD with BKP was performed in three patients who showed LCS associated with OVFs on MR images with progressive lower extremity neurological deficits. Clinical outcomes were assessed using the numerical rating scale (NRS) and the Japanese Orthopaedic Association (JOA) score. Radiological outcomes were evaluated using multiple parameters (i.e., fractured vertebral body height, lumbar lordosis [LL], and focal angle of the fractured vertebral body). Results: Over 6 postoperative months, the NRS and JOA scores were clearly improved while radiological parameters remained maintained (i.e., loss of fractured vertebral body height was only 0.3-1.4 mm in all cases). Two of the three cases showed restoration of LL and focal angle postoperatively. Conclusion: The combination of ULBD with BKP is an effective option for LCS aggravated by OVF.

Surgical management of brain metastasis as a part of systematic metastases from adenoid cystic carcinoma of the external auditory canal: illustrative case.

BACKGROUND: Adenoid cystic carcinoma (ACC) of the external auditory canal (EAC) is a rare tumor that accounts for approximately 5% of all EAC tumors. ACC is generally known as a slow-growing tumor, but patients often experience recurrence or distant metastasis in the long clinical course. While the major pattern of recurrence is pulmonary metastasis, brain metastasis of ACC of the EAC is rare. OBSERVATIONS: The authors describe the case of a 72-year-old male who was diagnosed with ACC of the EAC. Approximately 7 years later, brain magnetic resonance imaging revealed an intra-axial homogenously enhancing mass lesion that had no direct connection with the skull base in the left frontal lobe. The patient underwent tumor resection and histopathological examination revealed a mixture of cribriform and tubular patterns. The image and pathological characteristics of the tumor were similar to those of primary ACC or ACC from other sites of origin. LESSONS: While patients with ACC of the EAC often experience recurrence or distant metastasis in the long clinical course, they survive for a relatively long period of time, even though an optimal treatment has not been established. The authors therefore recommend surgical resection for brain metastasis of ACC of the EAC to improve neurological symptoms.

Augmented Reality Visualization-guided Microscopic Spine Surgery: Transvertebral Anterior Cervical Foraminotomy and Posterior Foraminotomy.

OBJECTIVE: We describe intraoperative augmented reality (AR) imaging to obtain a microscopic view in spine keyhole surgery. BACKGROUND: Minimally invasive keyhole surgery has been developed even for spine surgery, including transvertebral anterior cervical foraminotomy and posterior cervical laminoforaminotomy. These methods are complex and require a skillful technique. Therefore, inexperienced surgeons hesitate to perform keyhole surgeries. The technology used in surgery is rapidly advancing, including intraoperative imaging devices that have enabled AR imaging and facilitated complicated surgeries in many fields. However, data are not currently available on the use of AR imaging in spine surgery. The purpose of this article was to introduce the utility of AR for spine surgery. METHODS: We performed O-arm intraoperative imaging to create an augmented imaging model in navigation systems. Navigation data were linked to a microscope to merge the live view and AR. Augmented reality imaging shows the model plan in the real-world surgical field. We used this novel method in patients who underwent both keyhole surgeries. RESULTS: We successfully performed both surgeries using the AR visualization guide. CONCLUSIONS: The AR navigation system facilitates complicated keyhole surgeries in patients who undergo spine surgery. STUDY DESIGN: Technical report.