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Sumit N. Niogi, Neal Luther, Kenneth Kutner, Teena Shetty, Heather J. McCrea, Ronnie Barnes, Leigh Weiss, Russell F. Warren, Scott A. Rodeo, Robert D. Zimmerman, Apostolos John Tsiouris and Roger Härtl

OBJECTIVE

Statistical challenges exist when using diffusion tensor imaging (DTI) to assess traumatic axonal injury (TAI) in individual concussed athletes. The authors examined active professional American football players over a 6-year time period to study potential TAI after concussion and assess optimal methods to analyze DTI at the individual level.

METHODS

Active American professional football players recruited prospectively were assessed with DTI, conventional MRI, and standard clinical workup. Subjects underwent an optional preseason baseline scan and were asked to undergo a scan within 5 days of concussion during gameplay. DTI from 25 age- and sex-matched controls were obtained. Both semiautomated region-of-interest analysis and fully automated tract-based spatial statistics (TBSS) were used to examine DTI at individual and group levels. Statistical differences were assessed comparing individual DTI data to baseline imaging versus a normative database. Group-level comparisons were also performed to determine if longer exposure to professional-level play or prior concussion cause white matter microstructural integrity changes.

RESULTS

Forty-nine active professional football players were recruited into the study. Of the 49 players, 7 were assessed at baseline during the preseason and after acute concussion. An additional 18 players were assessed after acute concussion only. An additional 24 players had only preseason baseline assessments. The results suggest DTI is more sensitive to suspected TAI than conventional MRI, given that 4 players demonstrated decreased fractional anisotropy (FA) in multiple tracts despite normal conventional MRI. Furthermore, the data suggest individual assessment of DTI data using baseline premorbid imaging is more sensitive than typical methods of comparing data to a normative control group. Among all subjects with baseline data, 1 reduced FA tract (± 2.5 standard deviations) was found using the typical normative database reference versus 10 statistically significant (p < 0.05) reduced FA tracts when referencing internal control baseline data. All group-level comparisons were statistically insignificant (p > 0.05).

CONCLUSIONS

Baseline premorbid DTI data for individual DTI analysis provides increased statistical sensitivity. Specificity using baseline imaging also increases because numerous potential etiologies for reduced FA may exist prior to a concussion. These data suggest that there is a high potential for false-positive and false-negative assessment of DTI data using typical methods of comparing an individual to normative groups given the variability of FA values in the normal population.

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Peyton L. Nisson, Ibrahim Hussain, Roger Härtl, Samuel Kim and Ali A. Baaj

OBJECTIVE

An arachnoid web of the spine (AWS) is a rare and oftentimes challenging lesion to diagnose, given its subtle radiographic findings. However, when left untreated, this lesion can have devastating effects on a patient’s neurological function. To date, only limited case reports and series have been published on this topic. In this study, the authors sought to better describe this lesion, performing a systematic literature review and including 2 cases from their institution’s experience.

METHODS

A systematic literature search was performed in September 2018 that queried Ovid MEDLINE (1946–2018), PubMed (1946–2018), Wiley Cochrane Library: Central Register of Controlled Trials (1898–2018), and Thompson Reuters Web of Science: Citation Index (1900–2018), per PRISMA guidelines. Inclusion criteria specified all studies and case reports of patients with an AWS in which any relevant surgery types were considered and applied. Studies on arachnoid cysts and nonhuman populations, and those that did not report patient treatments or outcomes were excluded from the focus review.

RESULTS

A total of 19 records and 2 patients treated by the senior authors were included in the systematic review, providing a total of 43 patients with AWS. The mean age was 52 years (range 28–77 years), and the majority of patients were male (72%, 31/43). A syrinx was present in 67% (29/43) of the cases. All AWSs were located in the thoracic spine, and all but 2 (95%) were located dorsally (1 ventrally and 1 circumferentially). Weakness was the most frequently reported symptom (67%, 29/43), followed by numbness and/or sensory loss (65%, 28/43). Symptoms predominated in the lower extremities (81%, 35/43). It was found that nearly half (47%, 20/43) of patients had been experiencing symptoms for 1 year or longer before surgical intervention was performed, and 35% (15/43) of reports stated that symptoms were progressive in nature. The most commonly used surgical technique was a laminectomy with intradural excision of the arachnoid web (86%, 36/42). Following surgery, 91% (39/43) of patients had reported improvement in their neurological symptoms. The mean follow-up was 9.2 months (range 0–51 months).

CONCLUSIONS

AWS of the spine can be a debilitating disease of the spine with no more than an indentation of the spinal cord found on advanced imaging studies. The authors found this lesion to be reported in twice as many males than females, to be associated with a syrinx more than two-thirds of the time, and to only have been reported in the thoracic spine; over 90% of patients experienced improvement in their neurological function following surgery.

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Andreas Leidinger, Eliana E. Kim, Rodrigo Navarro-Ramirez, Nicephorus Rutabasibwa, Salim R. Msuya, Gulce Askin, Raphael Greving, Hamisi K. Shabani and Roger Härtl

OBJECTIVE

Spinal trauma is a major cause of disability worldwide. The burden is especially severe in low-income countries, where hospital infrastructure is poor, resources are limited, and the volume of cases is high. Currently, there are no reliable data available on incidence, management, and outcomes of spinal trauma in East Africa. The main objective of this study was to describe, for the first time, the demographics, management, costs of surgery and implants, treatment decision factors, and outcomes of patients with spine trauma in Tanzania.

METHODS

The authors retrospectively reviewed prospectively collected data on spinal trauma patients in the single surgical referral center in Tanzania (Muhimbili Orthopaedic Institute [MOI]) from October 2016 to December 2017. They collected general demographics and the following information: distance from site of trauma to the center, American Spinal Injury Association Impairment Scale (AIS), time to surgery, steroid use, and mechanism of trauma and AOSpine classification and costs. Surgical details and complications were recorded. Primary outcome was neurological status on discharge. The authors analyzed surgical outcome and determined predicting factors for positive outcome.

RESULTS

A total of 180 patients were included and analyzed in this study. The mean distance from site of trauma to MOI was 278.0 km, and the time to admission was on average 5.9 days after trauma. Young males were primarily affected (82.8% males, average age 35.7 years). On admission, 47.2% of patients presented with AIS grade A. Most common mechanisms of injury were motor vehicle accidents (28.9%) and falls from height (32.8%). Forty percent of admitted patients underwent surgery. The mean time to surgery was 33.2 days; 21.4% of patients who underwent surgery improved in AIS grade at discharge (p = 0.030). Overall, the only factor associated with improvement in neurological status was undergoing surgery (p = 0.03) and shorter time to surgery (p = 0.02).

CONCLUSIONS

This is the first study to describe the management and outcomes of spinal trauma in East Africa. Due to the lack of referral hospitals, patients are admitted late after trauma, often with severe neurological deficit. Surgery is performed but generally late in the course of hospital stay. The decision to perform surgery and timing are heavily influenced by the availability of implants and economic factors such as insurance status. Patients with incomplete deficits who may benefit most from surgery are not prioritized. The authors’ results suggest that surgery may have a positive impact on patient outcome. Further studies with a larger sample size are needed to confirm our results. These results provide strong support to implement evidence-based protocols for the management of spinal trauma.

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Harminder Singh, Sarang Rote, Ajit Jada, Evan D. Bander, Gustavo J. Almodovar-Mercado, Walid I. Essayed, Roger Härtl, Vijay K. Anand, Theodore H. Schwartz and Jeffrey P. Greenfield

The authors present 4 cases in which they used intraoperative CT (iCT) scanning to provide real-time image guidance during endonasal odontoid resection. While intraoperative CT has previously been used as a confirmatory test after resection, to the authors’ knowledge this is the first time it has been used to provide real-time image guidance during endonasal odontoid resection. The operating room setup, as well as the advantages and pitfalls of this approach, are discussed. A mobile intraoperative CT scanner was used in conjunction with real-time craniospinal neuronavigation in 4 patients who underwent endoscopic endonasal odontoidectomy for basilar invagination. All patients underwent a successful decompression. In 3 of the 4 patients, real-time intraoperative CT image guidance was instrumental in achieving a comprehensive decompression. In 3 (75%) cases in which the right nostril was the predominant working channel, there was a tendency for asymmetrical decompression toward the right side, meaning that residual bone was seen on the left, which was subsequently removed prior to completion of the surgery.

Endoscopic endonasal odontoid resection with real-time intraoperative image-guided CT scanning is feasible and provides accurate intraoperative localization of pathology, thereby increasing the chance of a complete odontoidectomy. For right-handed surgeons operating predominantly through the right nostril, special attention should be paid to the contralateral side of the resection, where there is often a tendency for residual pathology.

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Maria M. Santos, Derick K. Rubagumya, Imani Dominic, Amos Brighton, Soledad Colombe, Philip O’Donnell, Micaella R. Zubkov and Roger Härtl

OBJECTIVE

Infant hydrocephalus is estimated to affect more than 100,000 new infants each year in sub-Saharan Africa (SSA). Bugando Medical Centre (BMC), a government-funded and patient cost-shared referral center, serves over 13 million people in the Lake and Western regions of Tanzania. The goals of this study were to characterize the infant population affected by hydrocephalus who presented to BMC and were treated with a ventriculoperitoneal shunt (VPS) to determine the rate of early complications associated with this surgical procedure and to assess its potential risk factors.

METHODS

Data were prospectively collected from all patients less than 1 year of age who, over a period of 7 months, were diagnosed with hydrocephalus and admitted to BMC for insertion of a primary VPS. Demographic data, maternal history, preoperative studies, surgical procedure, and surgical complications developing by the time of the first follow-up visit were analyzed. Risk factors associated with the surgical complications were determined.

RESULTS

During the 7-month study period, 125 infants eligible for the study were included in the analysis. Overall, 75% were younger than 6 months of age, and 56% were males. Only 7% of mothers had a gestational ultrasound, 98% did not receive preconception folic acid, and 25% delivered their child at home. In most patients with hydrocephalus the etiology was uncertain (56%), and other patients had postinfectious (22.4%) or myelomeningocele-associated (16%) hydrocephalus. Patients’ mean head circumference on admission was 51.4 ± 6.3 cm. Their median age at shunt surgery was 137 days, and 22.4% of the patients were operated on without having undergone radiological assessment. The majority of shunts were placed in a right parietooccipital location. Thirteen patients had undergone a previous intraventricular endoscopic procedure. Overall, at least one surgical complication was found in 33.6% of patients up to the first follow-up assessment (median follow-up time of 70 days); shunt infection was the most common complication. The postoperative mortality rate was 9%. The risk factors associated with early surgical complications were tumor-related etiology, larger head circumference, and postoperative hospital stays of greater duration.

CONCLUSIONS

In a region of the continent where most infant hydrocephalus cases had an uncertain etiology, most patients presented to the hospital in a late stage, with no prenatal diagnosis and with large head circumferences. Standard preoperative investigations were not uniformly performed, and the surgical complications, led by VPS infection, were disturbingly high. Younger patient age, previous endoscopic procedure, surgeon involved, and cranial location of the VPS had no statistical relation to the surgical complications.

This study shows that the positive results previously reported by SSA mission hospitals, subspecialized in pediatric neurosurgery, are still not generalizable to every hospital in East Africa. To improve maternal and neonatal care in the Lake region of Tanzania, the development of a fluxogram to determine hydrocephalus etiology, a strict perioperative protocol for VPS insertion, and an increase in the number of endoscopic procedures are recommended to BMC.

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Marjan Alimi, Christoph P. Hofstetter, Se Young Pyo, Danika Paulo and Roger Härtl

OBJECT

Surgical decompression is the intervention of choice for lumbar spinal stenosis (LSS) when nonoperative treatment has failed. Standard open laminectomy is an effective procedure, but minimally invasive laminectomy through tubular retractors is an alternative. The aim of this retrospective case series was to evaluate the clinical and radiographic outcomes of this procedure in patients who underwent LSS and to compare outcomes in patients with and without preoperative spondylolisthesis.

METHODS

Patients with LSS without spondylolisthesis and with stable Grade I spondylolisthesis who had undergone minimally invasive tubular laminectomy between 2004 and 2011 were included in this analysis. Demographic, perioperative, and radiographic data were collected. Clinical outcome was evaluated using the Oswestry Disability Index (ODI) and visual analog scale (VAS) scores, as well as Macnab's criteria.

RESULTS

Among 110 patients, preoperative spondylolisthesis at the level of spinal stenosis was present in 52.5%. At a mean follow-up of 28.8 months, scoring revealed a median improvement of 16% on the ODI, 2.75 on the VAS back, and 3 on the VAS leg, compared with the preoperative baseline (p < 0.0001). The reoperation rate requiring fusion at the same level was 3.5%. Patients with and without preoperative spondylolisthesis had no significant differences in their clinical outcome or reoperation rate.

CONCLUSIONS

Minimally invasive laminectomy is an effective procedure for the treatment of LSS. Reoperation rates for instability are lower than those reported after open laminectomy. Functional improvement is similar in patients with and without preoperative spondylolisthesis. This procedure can be an alternative to open laminectomy. Routine fusion may not be indicated in all patients with LSS and spondylolisthesis.