Case-based explanation of standard work tools for selective dorsal rhizotomy for cerebral palsy.

OBJECTIVE: Spasticity is a challenging feature of cerebral palsy (CP) that may be managed with selective dorsal rhizotomy (SDR). Although standard work tools (SWTs) have recently been utilized to inform a standard of care for neurosurgical procedures, no SWTs for SDR have been previously described. The authors present the multidisciplinary approach SWTs for SDR used at their institutions to promote consistency in the field and minimize complication rates. METHODS: A multidisciplinary approach was used to define all steps in the SDR pathway. Preoperative, intraoperative, and postoperative workflows were synthesized, with specific efforts to improve mobility through inpatient rehabilitation and minimize infection. RESULTS: The SWTs have been implemented at two institutions for 7 years. An illustrative case of a patient aged 3 years 10 months with a history of premature birth at 29 weeks, spastic-diplegic CP, right-sided periventricular leukomalacia, and developmental delay who underwent L2-S1 SDR is presented. CONCLUSIONS: The authors detail SWTs for SDR developed by a multidisciplinary team with specific steps at all points in the patient pathway. The illustrative case emphasizes that SWTs may help ensure the safety of SDR while maximizing its long-term efficacy for individuals with CP.

Pediatric intraspinal arachnoid cyst: successful endoscopic fenestration. Illustrative case.

BACKGROUND: Intradural spinal arachnoid cysts (SACs) are a rare cause of spinal cord compression. Treatment is centered on decompression of the spinal cord via laminectomy or laminoplasty followed by resection or fenestration of the cyst. Although laminectomy or laminoplasty access may be needed to achieve the desired result, either procedure can be associated with more extensive surgical dissections and long-term spinal stability concerns, including postsurgical kyphosis. OBSERVATIONS: The authors present a case of a cervical intradural SAC in a 4-month-old girl presenting with symptomatic compression. The patient was treated by laminotomy and endoscopic fenestration of the SAC with resolution of symptoms and no disease progression 10 months postoperatively, when the patient was 14 months old. LESSONS: Microsurgical endoscopic fenestration of an intradural SAC can provide a less invasive means of treatment while avoiding the risks associated with more invasive approaches.

Stem Cell Implants: Emerging Innovation for Stroke Recovery.

Stroke is a debilitating neurovascular injury that those effects hundreds of thousands of Americans each year. Despite the high prevalence, disease morbidity and mortality, options for stroke intervention and rehabilitation are still limited. Stem cells have shown promise in stroke treatment due to their ability to self-renew and differentiate into different cell types. The primary sources of stem cells used today are bone marrow and fetal brain tissue, with mesenchymal stem cells, bone marrow stem cells and neural stem cells being particularly well-studied. By secreting therapeutic and neurogenic substances they are hypothesized to help foster recovery at the site of injury. Delivery mechanisms for stem cell therapy include intracerebral, intra-arterial, intraperitoneal, intravenous, intraventricular and intranasal routes with radiographic imaging now being used to monitor the progress of stem cell therapies. Stem cell implants have been found to be safe but optimal treatment strategies are still being established with several promising studies underway. Future efforts should continue to focus on improving efficacy, exploring alternative stem cell sources, enhancing migration capability and survival and educating stroke patients on the benefits and risks of stem cell therapy.

Concomitant brain abscess and spinal cord abscess in an immunocompetent teenage male: illustrative case.

BACKGROUND: Multiple bilateral brain abscesses occur rarely in immunocompetent patients. Hematogenous spread to the central nervous system (CNS) allows suppuration and abscess formation in the privileged immune environment of the CNS; hematogenous spread to the spinal cord is extremely rare and the combination of multifocal brain abscesses and intramedullary abscesses has not been reported. This report presents a rare presentation and diagrams a treatment algorithm involving iterative minimal access surgeries and prolonged medical management. OBSERVATIONS: The authors present a case of an 18-year-old male with numerous multifocal and bilateral intraparenchymal abscesses and a medically resistant C5 intramedullary spinal cord abscess. The symptomatic patient had a left oculomotor palsy and left hemiparesis, ultimately undergoing ultrasound-guided aspiration of abscesses in the left frontal and left cerebral peduncle. Following transient motor improvement, he evolved tetraparesis prompting spinal cord imaging and emergent ultrasound-guided needle aspiration of an occult C5 intramedullary spinal cord abscess. The patient received appropriate medical therapy, completed inpatient rehabilitation, and made a full recovery. LESSONS: Needle- and ultrasound-guided catheter drainage of CNS abscesses should be considered for symptomatic lesions. Following the neurological examination closely is extremely important; if the expected neurological improvement is delayed or regresses, then expanded imaging is warranted.

Thermal Damage Estimate Artifact Following Antecedent Biopsy: A Case Report.

MR-guided laser interstitial therapy (MRgLITT) is becoming more commonly used for minimal access approaches to intracranial lesions of all etiologies. The short-term safety profile of MRgLITT is favorable compared with sweeping incisions and open craniotomies, especially for lesions located in deep, periventricular, and highly eloquent areas. The Visualase software (Medtronic Inc., Minneapolis, MN, USA) has multiple adaptations to assist with this safety margin, including the thermal damage estimate (TDE), which applies predictive mathematical modeling to a two-dimensional (2D) graphical representation. TDE has been shown to highly correlate with actual tissue destruction in a priori MRgLITT cases and to anecdotally be imprecise when MRgLITT is combined with biopsy. We present a case regarding a 17-year-old male patient with intractable focal epilepsy. He underwent stereotactic biopsy and then ablation where it was shown that TDE is ~35% larger in the coronal plane than in the actual ablation zone. Air may have caused this artifact in the biopsy cavity, which affected the proton resonance frequency (PRF) and caused TDE pigment deposition. We believe in the need for a more comprehensive understanding and investigation regarding this TDE artifact. Future prospective studies into MRgLITT should attend carefully in cases where it is combined with biopsy.

Evolution via recombination: Cell-to-cell contact facilitates larger recombination events in Streptococcus pneumoniae.

Homologous recombination in the genetic transformation model organism Streptococcus pneumoniae is thought to be important in the adaptation and evolution of this pathogen. While competent pneumococci are able to scavenge DNA added to laboratory cultures, large-scale transfers of multiple kb are rare under these conditions. We used whole genome sequencing (WGS) to map transfers in recombinants arising from contact of competent cells with non-competent 'target' cells, using strains with known genomes, distinguished by a total of ~16,000 SNPs. Experiments designed to explore the effect of environment on large scale recombination events used saturating purified donor DNA, short-term cell assemblages on Millipore filters, and mature biofilm mixed cultures. WGS of 22 recombinants for each environment mapped all SNPs that were identical between the recombinant and the donor but not the recipient. The mean recombination event size was found to be significantly larger in cell-to-cell contact cultures (4051 bp in filter assemblage and 3938 bp in biofilm co-culture versus 1815 bp with saturating DNA). Up to 5.8% of the genome was transferred, through 20 recombination events, to a single recipient, with the largest single event incorporating 29,971 bp. We also found that some recombination events are clustered, that these clusters are more likely to occur in cell-to-cell contact environments, and that they cause significantly increased linkage of genes as far apart as 60,000 bp. We conclude that pneumococcal evolution through homologous recombination is more likely to occur on a larger scale in environments that permit cell-to-cell contact.