Use of Antibacterial Envelopes for Prevention of Infection in Neuromodulation Implantable Pulse Generators.

BACKGROUND: Neuromodulation unit placement carries a historic infection rate as high as 12%. Treatment of such requires surgical removal and a long course of systemic antibiotics. Antibiotic-impregnated envelopes have been effective in preventing infection in implantable cardiac devices. At our center, 1 surgeon uses these envelopes with all implanted neuromodulation units. OBJECTIVE: To assess the efficacy of antibacterial envelopes in prevention of infection in neuromodulation device placement. METHODS: We conducted a retrospective cohort study of consecutive implantable pulse generator (IPG) unit implantation with an antibacterial envelope at a single center between October 2014 and December 2019. We collected demographic data, including postoperative infections, reoperations, and complications, associated with the IPGs. This cohort was then compared with a historical cohort of consecutive patients undergoing surgery before envelope usage (October 2007-April 2014). RESULTS: In the pre-envelope cohort of 151 IPGs placed in 116 patients, there were 18 culture-confirmed infections (11.9%). In the antibacterial envelope cohort of 233 IPGs placed in 185 patients, there were 5 culture-confirmed infections (2.1%). The absolute risk reduction of the antibacterial envelope was 9.85% (95% CI 4.3%-15.4%, P < .01). The number needed to treat was 10.1 (95% CI 6.5-23.1, P < .01) envelopes to prevent 1 IPG infection. CONCLUSION: We saw a reduced rate of infections in the antibacterial envelope cohort. Although this is likely multifactorial, our results suggest a benefit of antibacterial envelopes on infection after neuromodulation surgery.

Pediatric thalamic tumors in the MRI era: a Canadian perspective.

BACKGROUND: Thalamic gliomas are rare. The natural history is unpredictable, and the optimal management of these tumors in children is poorly defined. The aim was to identify outcomes, prognostic factors, and response to various modalities of treatment in a relatively large population of pediatric thalamic tumors from many centers within a fairly homogeneous health care system. METHODS: We performed a Canadian multicenter retrospective review of pediatric thalamic tumors presenting during the MRI era (1989-2012). Radiology and pathology were reviewed by central independent reviewers. Paraffin shavings for RNA extraction were taken and tested for fusion events involving KIAA1549:BRAF. Tumors were classified as unilateral or bithalamic based on their origin on imaging. Univariate and multivariate analyses on factors influencing survival were performed. RESULTS: Seventy-two thalamic tumors were identified from 11 institutions. Females represented 53% of the study population, and the mean age at presentation was 8.9 years. Sixty-two tumors were unilateral and 10 bithalamic. Unilateral tumors had a greater propensity to grow inferiorly towards the brainstem. These tumors were predominantly low grade in comparison to bithalamic tumors which were high-grade astrocytomas. The 5-year overall survival was 61 ± 13% for unithalamic tumors compared to 37 ± 32% for bithalamic tumors (p = 0.097). Multivariate analysis indicated tumor grade as the only significant prognostic factor for unithalamic tumors. Six unilateral tumors, all low grade, were BRAF fusion positive. CONCLUSION: Unilateral and bilateral thalamic tumors behave differently. Surgical resection is an appropriate treatment option in unilateral tumors, most of which are low grade, but outcome is not related to extent of resection (EOR). Bilateral thalamic tumors have a poorer prognosis, but the occasional patient does remarkably well. The efficacy of chemotherapy and radiotherapy has not been clearly demonstrated. Novel therapeutic approaches are required to improve the prognosis for malignant unilateral thalamic tumors and bilateral thalamic tumors.

Thalamic stimulation in multiple sclerosis: evidence for a 'demyelinative thalamotomy'.

The mechanism of action of deep brain stimulation (DBS) in the alleviation of tremor in multiple sclerosis (MS) and other neurological disorders is unknown. Moreover, whether the trauma accompanying this surgery is responsible for the induction of new MS plaques is controversial. Here we report the first description of the post-mortem imaging and pathologic findings in the brain of a MS patient who underwent thalamic DBS for the treatment of MS-induced tremor. MR imaging of formalin-fixed brain slices was carried out at 1.5, 3 and 7 Tesla and correlated with the histopathology. There were numerous demyelinative plaques in the white mater, cortex and deep gray matter. There were no plaques along the DBS tract within the sections that sampled the deep hemispheric white matter. However, deep within the thalamus focal demyelination approximated the tract, particularly in the region corresponding to the electrical field. The findings in this single case raise the possibility that focal demyelination may be induced by the electrical field and this may be responsible for long-lasting alleviation of tremor in the absence of continued electrostimulation.

Resolution of syringomyelia and Chiari malformation after growth hormone therapy.

INTRODUCTION: The association between hypopituitarism, Chiari I malformation, and syringomyelia has been recently recognized. Most of the reported patients suffered perinatal injury or asphyxia. MATERIALS AND METHODS: We present the case of a premature child without identifiable perinatal injury, who was recognized to have growth hormone (GH) deficiency, Chiari I malformation, and syringohydromyelia. CONCLUSION: There was a resolution of syrinx and tonsillar herniation after GH replacement.

Acquired encephalocele attributable to tuberculous osteitis: case report.

OBJECTIVE: There are many forms of calvarial tuberculosis. In this case report, extensive calvarial tuberculosis caused a large cranial defect and occlusion of the sigmoid sinus in a 10-year-old child. This resulted in a transient increase of the intracranial pressure and formation of an acquired encephalocele. CLINICAL PRESENTATION: A 10-year-old boy presented with an acquired, infected encephalocele and features of tuberculous mastoiditis. Computed tomographic and magnetic resonance imaging scans demonstrated evidence of left occipital encephalocele with left mastoiditis, extradural granulations, bone destruction, and complete occlusion of the left sigmoid sinus. INTERVENTION: The encephalocele was surgically excised and combined with left mastoidectomy. Although no mycobacterium had been demonstrated in the excised lesion, the presence of active tuberculous infection in the mastoid led to the conclusion that the bone destruction leading to encephalocele was secondary to the calvarial tuberculosis. The patient received antituberculous treatment with clinical improvement. CONCLUSION: This is the first report of calvarial tuberculosis causing a cranial defect and venous sinus thrombosis and resulting in an acquired encephalocele. Surgical excision combined with medical treatment was curative.

Multiple intracranial tumors in Philadelphia chromosome positive acute lymphoblastic leukemia: successful treatment following aggressive supportive care, early cranial radiation, high dose chemotherapy and imatinib.

We report the first case of multiple intracranial tumors ("chloromas") at diagnosis of Philadelphia chromosome positive acute lymphoblastic leukemia. The patient presented comatose with signs of cerebral herniation. Initial management of raised intracranial pressure and hyperleukocytosis followed by emergent whole brain radiation therapy reversed the life-threatening neurological signs. High-dose chemotherapy combined with daily imatinib mesylate induced a rapid and sustained bone marrow remission. Ongoing rehabilitation resulted in a near complete neurological recovery within 6 months of diagnosis. This outcome justifies aggressive early management of increased intracranial pressure and hyperleukocytosis in future similar presentations.

Depressed skull fracture and epidural hematoma from head fixation with pins for craniotomy in children.

OBJECTIVE: A head fixation device with pins is commonly used for immobilization of the patient's head during craniotomy. The safety of head fixation devices in children has been discussed rarely in the literature. The purpose of this report is to review our experience with complications of head fixation with pins in children undergoing craniotomies and to review the literature on this subject. MATERIALS AND METHODS: The database of the Division of Neurosurgery was reviewed to identify children who had cranial complications related to the use of a pin head fixation device. The charts of these patients were reviewed retrospectively. RESULTS: Five of 766 children (0.65%) undergoing craniotomies with pin fixation of the head had depressed skull fractures and/or epidural hematomas from the pin fixation. Age ranged from 2.6 to 7.5 years; all fractures were temporal and occurred during posterior fossa craniotomies. CONCLUSIONS: Depressed skull fractures and associated epidural hematomas need to be considered as possible complications of pin fixation of the head for craniotomy in young children.

Brown-Sèquard syndrome produced by C3-C4 cervical disc herniation: a case report and review of the literature.

STUDY DESIGN: The article presents a case in which Brown-Sèquard syndrome resulted from a painless C3-C4 disc herniation. OBJECTIVE: To raise spinal surgeons' awareness of this unusual clinical problem. SUMMARY OF BACKGROUND DATA: Brown-Sèquard syndrome involves ipsilateral loss of motor function combined with contralateral loss of pain and temperature sensation. Brown-Sèquard syndrome is commonly seen in the setting of spinal trauma or an extramedullary spinal neoplasm, but rarely it can be caused by a herniated cervical disc. METHODS: A 46-year-old man presented with progressive numbness and weakness in the left arm, mild neck pain, and reduced temperature sensation on the right side of the body. There was weakness in left arm and leg and proximal right lower limb. Magnetic resonance imaging showed large C3-C4 disc herniation compressing the spinal cord at that level. Anterior cervical discectomy and fusion with iliac crest bone graft was performed. RESULTS: Follow-up showed complete resolution of the neck pain, normal sensory function, and complete recovery of motor power in the left upper and right lower limb. There was a slight residual weakness in the left leg. CONCLUSION: Brown-Sèquard syndrome is rarely caused by a cervical disc herniation. This etiology may be underdiagnosed but has a more favorable outcome in those cases where rapid diagnosis is followed by spinal cord decompression.

Isolated C3-C4 disc herniations present as a painless myelopathy.

BACKGROUND CONTEXT: Cervical disc herniations at the C3-C4 level are distinctly uncommon. The authors present the first case series of isolated C3-C4 disc herniations presenting with myelopathy. PURPOSE: To elucidate a rare presentation of the uncommon C3-C4 disc herniation. STUDY DESIGN: Case series. PATIENT SAMPLE: The four patients who presented with myelopathy caused by isolated C3-C4 disc herniations, at the spine unit, Vancouver General Hospital between 1999 and 2005. OUTCOME MEASURE: Improvement in neurological status. METHODS: We retrospectively reviewed the files of the patients. The clinical features and outcome of surgery were assessed. RESULTS: The C3-C4 disc herniation can present as with no or mild pain, and hand numbness was a prominent symptom. Early recognition and treatment led to favorable outcome. CONCLUSIONS: Myelopathy is rarely caused by a C3-C4 disc herniation. This etiology may be underdiagnosed but has a more favorable outcome in those cases where rapid diagnosis is followed by spinal cord decompression.