Jonathan E. Martin, William Harkness, and Mary Edwards
Jonathan E. Martin, Markus Bookland, Douglas Moote, and Catherine Cebulla
Grabb’s line—the perpendicular distance from the basion-C2 line (pB-C2)—is a widely used radiographic measurement with significant clinical implications in patients with a complex Chiari malformation. Rigorous demonstration of the reproducibility of this measurement has not previously been reported. The authors report a standardized measurement technique with excellent inter- and intrarater reliability on T1-weighted sagittal MRI.
The authors developed a standardized measurement technique that included specifications of midline slice selection, landmark and reference line definitions, and measurement technique on T1-weighted sagittal images. Twenty MR images were reviewed by 2 pediatric neurosurgeons, 1 pediatric radiologist, and 1 undergraduate student. Measurements were performed using the technique specified on 2 separate occasions. Intrarater and interrater reliabilities were calculated using the intraclass correlation coefficient.
A combined interrater reliability of 0.879 was achieved for the pB-C2, and 0.916 for the clival-canal angle, another measure of interest in patients with complex Chiari malformations. Intrarater reliability for these measurements exceeded 0.858 for all 4 reviewers.
Grabb’s line—the pB-C2—can be measured with excellent reliability using a standardized measurement protocol. Individual clinicians and collaborative databases should consider using validated measurement techniques to guide clinical decision making in patients with craniocervical junction pathology.
Jonathan E. Martin, Thomas Manning, Markus Bookland, and Charles Castiglione
Minimally invasive (MI) synostectomy with postoperative helmet orthosis is increasingly used in the management of sagittal craniosynostosis. Although the MI technique reduces or eliminates the need for access to the lateral skull surface, the modified prone/sphinx position remains popular. The authors present their initial experience with supine positioning for MI sagittal synostectomy.
The authors used supine positioning with the head turned laterally on a horseshoe head holder in 5 consecutive patients undergoing MI sagittal synostectomy.
Resection of the sagittal suture from the anterior to posterior fontanel was accomplished in all patients. Surgical time averaged 70 minutes. No patient required transfusion. The posttreatment cephalic index averaged 83%.
Initial experience with supine positioning for MI sagittal synostectomy suggests that the technique can be used as an alternative to the modified prone position, with the potential to reduce anesthetic risk in these patients.
Jonathan E. Martin, Christopher J. Neal, William T. Monacci, and David J. Eisenman
✓ Superior semicircular canal dehiscence is a recently described condition resulting in pressure-induced vertigo in affected patients. The diagnosis is established with the appearance of characteristic electronystagmographic and neuroimaging findings. This condition is amenable to surgical treatment by resurfacing of the dehiscence in the defect in the middle cranial fossa floor with preservation of superior semicircular canal function. The authors report on the treatment of a 35-year-old man with superior semicircular canal dehiscence by a joint neurosurgical and otolaryngological team.
Jonathan E. Martin, Richard J. Teff, and Philip C. Spinella
Care for host-nation pediatric casualties and disease or nonbattle injuries is an essential mission of deployed military medical assets. Clinical experience with pediatric patients at field hospitals has been increasingly reported since 2001, with neurotrauma identified as a major cause of morbidity and death in this population. A concentrated pediatric neurosurgical experience at a deployed medical facility has not been reported. The authors reviewed their experience with pediatric neurosurgical patients at a field hospital in Iraq in 2007 to provide insight into the management of this patient population.
A retrospective review was conducted using a prospective database constructed by the authors for quality improvement during a single combat rotation in 2007.
Forty-two patients among 287 consultations were 17 years of age or younger. Twenty-six of these children were 8 years old or younger. Penetrating head injuries were the most common indication for consultation (22 of 42 patients). Twenty-eight of 130 surgical procedures were performed in the children. One patient died in the perioperative period, for a trauma-related operative mortality rate of 4%. Seven patients received palliative care based on the extent of presenting injuries. Twenty-five patients were discharged with minimal or no neurological deficits.
Pediatric patients represent a significant proportion of the neurosurgical patient volume at field medical hospitals in the Iraqi theater. The mature medical theater environment present in 2007 allowed for remarkable diagnostic evaluation and treatment of these patients. Penetrating and closed craniospinal injuries were the most common indication for consultation. Disease and nonbattle injuries were also encountered, with care provided when deemed appropriate. The deployed environment presents unique medical and ethical challenges to neurosurgeons serving in forward medical facilities.
Markus J. Bookland, Edward S. Ahn, Petronella Stoltz, and Jonathan E. Martin
The authors sought to evaluate the accuracy of a novel telehealth-compatible diagnostic software system for identifying craniosynostosis within a newborn (< 1 year old) population. Agreement with gold standard craniometric diagnostics was also assessed.
Cranial shape classification software accuracy was compared to that of blinded craniofacial specialists using a data set of open-source (n = 40) and retrospectively collected newborn orthogonal top-down cranial images, with or without additional facial views (n = 339), culled between April 1, 2008, and February 29, 2020. Based on image quality, midface visibility, and visibility of the cranial equator, 351 image sets were deemed acceptable. Accuracy, sensitivity, and specificity were calculated for the software versus specialist classification. Software agreement with optical craniometrics was assessed with intraclass correlation coefficients.
The cranial shape classification software had an accuracy of 93.3% (95% CI 86.8–98.8; p < 0.001), with a sensitivity of 92.0% and specificity of 94.3%. Intraclass correlation coefficients for measurements of the cephalic index and cranial vault asymmetry index compared to optical measurements were 0.95 (95% CI 0.84–0.98; p < 0.001) and 0.67 (95% CI 0.24–0.88; p = 0.003), respectively.
These results support the use of image processing–based neonatal cranial deformity classification software for remote screening of nonsyndromic craniosynostosis in a newborn population and as a substitute for optical scanner– or CT-based craniometrics. This work has implications that suggest the potential for the development of software for a mobile platform that would allow for screening by telemedicine or in a primary care setting.
David S. Hersh, William A. Lambert, Markus J. Bookland, and Jonathan E. Martin
Surgical options for metopic craniosynostosis include the traditional open approach or a minimally invasive approach that typically involves an endoscopy-assisted strip craniectomy. The minimally invasive approach has been associated with less blood loss and operative time, a lower transfusion rate, and a shorter length of stay. Additionally, it is more cost-effective than open reconstruction, despite the need for a postoperative cranial orthosis and multiple follow-up visits. The authors describe a variation of the minimally invasive approach using a lighted retractor to perform a strip craniectomy of the metopic suture in a 2-month-old patient with metopic craniosynostosis.
The video can be found here: https://vimeo.com/511237503.
Brian T. Ragel, Paul Klimo Jr., Jonathan E. Martin, Richard J. Teff, Hans E. Bakken, and Rocco A. Armonda
Decompressive craniectomy (DC) with dural expansion is a life-saving neurosurgical procedure performed for recalcitrant intracranial hypertension due to trauma, stroke, and a multitude of other etiologies. Illustratively, we describe technique and lessons learned using DC for battlefield trauma.
Neurosurgical operative logs from service (October 2007 to September 2009) in Afghanistan that detail DC cases for trauma were analyzed. Illustrative examples of frontotemporoparietal and bifrontal DC that depict battlefield experience performing these procedures are presented with attention drawn to the L.G. Kempe hemispherectomy incision, brainstem decompression techniques, and dural onlay substitutes.
Ninety craniotomies were performed for trauma over the time period analyzed. Of these, 28 (31%) were DCs. Of the 28 DCs, 24 (86%) were frontotemporoparietal DCs, 7 (25%) were bifrontal DCs, and 2 (7%) were suboccipital DCs. Decompressive craniectomies were performed for 19 penetrating head injuries (13 gunshot wounds and 6 explosions) and 9 severe closed head injuries (6 war-related explosions and 3 others).
Thirty-one percent of craniotomies performed for trauma were DCs. Battlefield neurosurgeons use DC to allow for safe transfer of neurologically ill patients to tertiary military hospitals, which can be located 8–18 hours from a war zone. The authors recommend the L.G. Kempe incision for blood supply preservation, large craniectomies to prevent brain strangulation over bone edges, minimal brain debridement, adequate brainstem decompression, and dural onlay substitutes for dural closure.
Jonathan E. Martin, Brandon G. Rocque, Andrew Jea, Richard C. E. Anderson, Joshua Pahys, and Douglas Brockmeyer
Hypermobility of the craniocervical junction (CCJ) in patients with Down syndrome (DS) is common. Whereas atlantoaxial (C1–2) hypermobility is well characterized, occipitoatlantal (Oc–C1) laxity is recognized but poorly defined. A clear understanding of the risks associated with DS-related hypermobility is lacking. Research efforts to address the topic of axial cervical spine instability in the patient with DS require a reliable and reproducible means of assessing CCJ mobility. The authors conducted a pilot study comparing two methods of quantifying motion of the CCJ on dynamic (flexion/extension) plain radiographs: the delta–condyle-axial interval (ΔCAI) and the delta–basion-axial interval (ΔBAI) methods.
Dynamic radiographs from a cohort of 10 patients with DS were evaluated according to prescribed standards. Independent movement of Oc–C1, C1–2, and Oc–C2 was calculated. Interrater and intrarater reliability for CCJ mobility was then calculated for both techniques.
Measurement using the ΔCAI technique had excellent fidelity with intraclass correlation coefficients (ICCs) of 0.77, 0.71, and 0.80 for Oc–C1, C1–2, and Oc–C2, respectively. The ΔBAI technique had lower fidelity, yielding respective ICCs of 0.61, 0.65, and 0.50.
This pilot study suggests that ΔCAI is a superior measurement technique compared to ΔBAI and may provide reliable assessment of the mobility of the CCJ on dynamic radiographs in the pediatric patient with DS. The use of reliable and reproducible measurement techniques strengthens the validity of research derived from pooled database efforts.