Intracranial hypotension is a rare condition caused by spontaneous or iatrogenic CSF leaks that alter normal CSF dynamics. Symptoms range from mild headaches to transtentorial herniation, coma, and death. Duret hemorrhages have been reported to occur in some patients with this condition and are traditionally believed to be associated with a poor neurological outcome. A 73-year-old man with a remote history of spinal fusion presented with syncope and was found to have small subdural hematomas on head CT studies. He was managed nonoperatively and discharged with a Glasgow Coma Scale score of 15, only to return 3 days later with obtundation, fixed downward gaze, anisocoria, and absent cranial nerve reflexes. A CT scan showed Duret hemorrhages and subtle enlargement of the subdural hematomas, though the hematomas remained too small to account for his poor clinical condition. Magnetic resonance imaging of the spine revealed a large lumbar pseudomeningocele in the area of prior fusion. His condition dramatically improved when he was placed in the Trendelenburg position and underwent repair of the pseudomeningocele. He was kept flat for 7 days and was ultimately discharged in good condition. On long-term follow-up, his only identifiable deficit was diplopia due to an internuclear ophthalmoplegia. Intracranial hypotension is a rare condition that can cause profound morbidity, including tonsillar herniation and brainstem hemorrhage. With proper identification and treatment of the CSF leak, patients can make functional recoveries.
Robert H. Bonow, James W. Bales, Ryan P. Morton, Michael R. Levitt, and Fangyi Zhang
Robert H. Bonow, Christopher C. Young, David I. Bass, Anne Moore, and Michael R. Levitt
Transcranial Doppler (TCD) ultrasonography is an inexpensive, noninvasive means of measuring blood flow within the arteries of the brain. In this review, the authors outline the technology underlying TCD ultrasonography and describe its uses in patients with neurosurgical diseases. One of the most common uses of TCD ultrasonography is monitoring for vasospasm following subarachnoid hemorrhage. In this setting, elevated blood flow velocities serve as a proxy for vasospasm and can herald the onset of ischemia. TCD ultrasonography is also useful in the evaluation and management of occlusive cerebrovascular disease. Monitoring for microembolic signals enables stratification of stroke risk due to carotid stenosis and can also be used to clarify stroke etiology. TCD ultrasonography can identify patients with exhausted cerebrovascular reserve, and after extracranial-intracranial bypass procedures it can be used to assess adequacy of flow through the graft. Finally, assessment of cerebral autoregulation can be performed using TCD ultrasonography, providing data important to the management of patients with severe traumatic brain injury. As the clinical applications of TCD ultrasonography have expanded over time, so has their importance in the management of neurosurgical patients. Familiarity with this diagnostic tool is crucial for the modern neurological surgeon.
Christopher C. Young, Robert H. Bonow, Guilherme Barros, Mahmud Mossa-Basha, Louis J. Kim, and Michael R. Levitt
Cerebrovascular diseases manifest as abnormalities of and disruption to the intracranial vasculature and its capacity to carry blood to the brain. However, the pathogenesis of many cerebrovascular diseases begins in the vessel wall. Traditional luminal and perfusion imaging techniques do not provide adequate information regarding the differentiation, onset, or progression of disease. Intracranial high-resolution MR vessel wall imaging (VWI) has emerged as an invaluable technique for understanding and evaluating cerebrovascular diseases. The location and pattern of contrast enhancement in intracranial VWI provides new insight into the inflammatory etiology of cerebrovascular diseases and has potential to permit earlier diagnosis and treatment. In this report, technical considerations of VWI are discussed and current applications of VWI in vascular malformations, blunt cerebrovascular injury/dissection, and steno-occlusive cerebrovascular vasculopathies are reviewed.
Isaac Josh Abecassis, Christopher C. Young, David J. Caldwell, Abdullah H. Feroze, John R. Williams, R. Michael Meyer, Ryan T. Kellogg, Robert H. Bonow, and Randall M. Chesnut
Decompressive craniectomy (DC) is an effective, lifesaving option for reducing intracranial pressure (ICP) in traumatic brain injury (TBI), stroke, and other pathologies with elevated ICP. Most DCs are performed via a standard trauma flap shaped like a reverse question mark (RQM), which requires sacrificing the occipital and posterior auricular arteries and can be complicated by wound dehiscence and infections. The Ludwig Kempe hemispherectomy incision (Kempe) entails a T-shaped incision, one limb from the midline behind the hairline to the inion and the other limb from the root of the zygoma to the coronal suture. The authors’ objective in this study was to define their implementation of the Kempe incision for DC and craniotomy, report clinical outcomes, and quantify the volume of bone removed compared with the RQM incision.
A retrospective review of a single-surgeon experience with DC in TBI and stroke was performed. Patient demographics, imaging, and outcomes were collected for all DCs from 2015 to 2020, and the incisions were categorized as either Kempe or RQM. Preoperative and postoperative CT scans were obtained and processed using a combination of automatic segmentation (in Python and SimpleITK) with manual cleanup and further subselection in ITK-SNAP. The volume of bone removed was quantified, and the primary outcome was percentage of hemicranium removed. Postoperative surgical wound infections, estimated blood loss (EBL), and length of surgery were compared between the two groups as secondary outcomes. Cranioplasty data were collected.
One hundred thirty-six patients were included in the analysis; there were 57 patients in the craniotomy group (44 patients with RQM incisions and 13 with Kempe incisions) and 79 in the craniectomy group (41 patients with RQM incisions and 38 Kempe incisions). The mean follow-up for the entire cohort was 251 ± 368 days. There was a difference in the amount of decompression between approaches in multivariate modeling (39% ± 11% of the hemicranium was removed via the Kempe incision vs 34% ± 10% via the RQM incision, p = 0.047), although this did not achieve significance in multivariate modeling. Wound infection rates, EBL, and length of surgery were comparable between the two incision types. No wound infections in either cohort were due to wound dehiscence. Cranioplasty outcomes were comparable between the two incision types.
The Kempe incision for craniectomy or craniotomy is a safe, feasible, and effective alternative to the RQM. The authors advocate the Kempe incision in cases in which contralateral operative pathology or subsequent craniofacial/skull base repair is anticipated.
Chibawanye I. Ene, Anthony C. Wang, Kelly L. Collins, Robert H. Bonow, Lynn B. McGrath, Sharon J. Durfy, Jason K. Barber, and Richard G. Ellenbogen
While a select population of pediatric patients with Chiari malformation type I (CM-I) remain asymptomatic, some patients present with tussive headaches, neurological deficits, progressive scoliosis, and other debilitating symptoms that necessitate surgical intervention. Surgery entails a variety of strategies to restore normal CSF flow, including increasing the posterior fossa volume via bone decompression only, or bone decompression with duraplasty, with or without obex exploration. The indications for duraplasty and obex exploration following bone decompression remain controversial. The objective of this study was to describe an institutional series of pediatric patients undergoing surgery for CM-I, performed by a single neurosurgeon. For patients presenting with a syrinx, the authors compared outcomes following bone-only decompression with duraplasty only and with duraplasty including obex exploration. Clinical outcomes evaluated included resolution of syrinx, scoliosis, presenting symptoms, and surgical complications.
A retrospective review was conducted of the medical records of 276 consecutive pediatric patients with CM-I operated on at a single institution between 2001 and 2015 by the senior author. Imaging findings of tonsillar descent, associated syrinx (syringomyelia or syringobulbia), basilar invagination, and clinical assessment of CM-I–attributable symptoms and scoliosis were recorded. In patients presenting with a syrinx, clinical outcomes, including syrinx resolution, symptom resolution, and impact on scoliosis progression, were compared for three surgical groups: bone-only/posterior fossa decompression (PFD), PFD with duraplasty (PFDwD), and PFD with duraplasty and obex exploration (PFDwDO).
PFD was performed in 25% of patients (69/276), PFDwD in 18% of patients (50/276), and PFDwDO in 57% of patients (157/276). The mean follow-up was 35 ± 35 months. Nearly half of the patients (132/276, 48%) had a syrinx. In patients presenting with a syrinx, PFDwDO was associated with a significantly higher likelihood of syrinx resolution relative to PFD only (HR 2.65, p = 0.028) and a significant difference in time to symptom resolution (HR 2.68, p = 0.033). Scoliosis outcomes did not differ among treatment groups (p = 0.275). Complications were not significantly higher when any duraplasty (PFDwD or PFDwDO) was performed following bone decompression (p > 0.99).
In this series of pediatric patients with CM-I, patients presenting with a syrinx who underwent expansile duraplasty with obex exploration had a significantly greater likelihood of syrinx and symptom resolution, without increased risk of CSF-related complications, compared to those who underwent bone-only decompression.
Robert H. Bonow, Cordelie E. Witt, Mahmud Mossa-Basha, Joseph Cuschieri, Saman Arbabi, Monica S. Vavilala, Frederick P. Rivara, and Randall M. Chesnut
The goal of this study was to compare the odds of stroke 24 hours or more after hospital arrival among patients with blunt cerebrovascular injury (BCVI) who were treated with therapeutic anticoagulation versus aspirin.
The authors conducted a retrospective cohort study at a regional level I trauma center including all patients with BCVI who were treated over a span of 10 years. Individuals with stroke on arrival or within the first 24 hours were excluded, as were those receiving alternative antithrombotic drugs or procedural treatment. Exact logistic regression was used to examine the association between treatment and stroke, adjusting for injury grade. To account for the possibility of residual confounding, propensity scores for the likelihood of receiving anticoagulation were determined and used to match patients from each treatment group; the difference in the probability of stroke between the two groups was then calculated.
A total of 677 patients with BCVI receiving aspirin or anticoagulation were identified. A total of 3.8% (n = 23) of 600 patients treated with aspirin sustained a stroke, compared to 11.7% (n = 9) of 77 receiving anticoagulation. After adjusting for injury grade with exact regression, anticoagulation was associated with higher likelihood of stroke (OR 3.01, 95% CI 1.00–8.21). In the propensity-matched analysis, patients who received anticoagulation had a 15.0% (95% CI 3.7%–26.3%) higher probability of sustaining a stroke compared to those receiving aspirin.
Therapeutic anticoagulation may be inferior to aspirin for stroke prevention in BCVI. Prospective research is warranted to definitively compare these treatment strategies.
Ariana S. Barkley, Laura J. Spece, Lia M. Barros, Robert H. Bonow, Ali Ravanpay, Richard Ellenbogen, Phearum Huoy, Try Thy, Seang Sothea, Sopheak Pak, James LoGerfo, and Abhijit V. Lele
The high global burden of traumatic brain injury (TBI) disproportionately affects low- and middle-income countries (LMICs). These settings also have the greatest disparity in the availability of surgical care in general and neurosurgical care in particular. Recent focus has been placed on alleviating this surgical disparity. However, most capacity assessments are purely quantitative, and few focus on concomitantly assessing the complex healthcare system needs required to care for these patients. The objective of the present study was to use both quantitative and qualitative assessment data to establish a comprehensive approach to inform capacity-development initiatives for TBI care at two hospitals in an LMIC, Cambodia.
This mixed-methods study used 3 quantitative assessment tools: the World Health Organization Personnel, Infrastructure, Procedures, Equipment, Supplies (WHO PIPES) checklist, the neurosurgery-specific PIPES (NeuroPIPES) checklist, and the Neurocritical Care (NCC) checklist at two hospitals in Phnom Penh, Cambodia. Descriptive statistics were obtained for quantitative results. Qualitative semistructured interviews of physicians, nurses, and healthcare administrators were conducted by a single interviewer. Responses were analyzed using a thematic content analysis approach and coded to allow categorization under the PIPES framework.
Of 35 healthcare providers approached, 29 (82.9%) participated in the surveys, including 19 physicians (65.5%) and 10 nurses (34.5%). The majority had fewer than 5 years of experience (51.7%), were male (n = 26, 89.7%), and were younger than 40 years of age (n = 25, 86.2%). For both hospitals, WHO PIPES scores were lowest in the equipment category. However, using the NCC checklist, both hospitals scored higher in equipment (81.2% and 62.7%) and infrastructure (78.6% and 69.6%; hospital 1 and 2, respectively) categories and lowest in the training/continuing education category (41.7% and 33.3%, hospital 1 and 2, respectively). Using the PIPES framework, analysis of the qualitative data obtained from interviews revealed a need for continuing educational initiatives for staff, increased surgical and critical care supplies and equipment, and infrastructure development. The analysis further elucidated barriers to care, such as challenges with time availability for experienced providers to educate incoming healthcare professionals, issues surrounding prehospital care, maintenance of donated supplies, and patient poverty.
This mixed-methods study identified areas in supplies, equipment, and educational/training initiatives as areas for capacity development for TBI care in an LMIC such as Cambodia. This first application of the NCC checklist in an LMIC setting demonstrated limitations in its use in this setting. Concomitant qualitative assessments provided insight into barriers otherwise undetected in quantitative assessments.