Bradley N. Bohnstedt

Analysis of the risk of shunt failure or infection related to cerebrospinal fluid cell count, protein level, and glucose levels in low-birth-weight premature infants with posthemorrhagic hydrocephalus

OBJECT Premature, low-birth-weight infants with posthemorrhagic hydrocephalus have a high risk of shunt obstruction and infection. Established risk factors for shunt failure include grade of the hemorrhage and age at shunt insertion. There is anecdotal evidence that the amount of red blood cells or protein levels in the CSF may affect shunt performance. However, this has not been analyzed specifically for this cohort of high-risk patients. Therefore, the authors performed this study to examine whether any statistical relationship exists between the CSF constituents and the rate of shunt malfunction or infection in this population. METHODS A retrospective cohort study was performed on premature infants born at Riley Hospital for Children from 2000 to 2009. Inclusion criteria were a CSF sample analyzed within 2 weeks prior to shunt insertion, low birth weight (< 1500 grams), prematurity (birth prior to 37 weeks estimated gestational age), and shunt insertion for posthemorrhagic hydrocephalus. Data points included the gestational age at birth and shunt insertion, weight at birth and shunt insertion, history of CNS infection prior to shunt insertion, shunt failure, shunt infection, and the levels of red blood cells, white blood cells, protein, and glucose in the CSF. Statistical analysis was performed to determine any association between shunt outcome and the CSF parameters. RESULTS Fifty-eight patients met the study entry criteria. Ten patients (17.2%) had primary shunt failure within 3 months of insertion. Nine patients (15.5%) had shunt infection within 3 months. A previous CNS infection prior to shunt insertion was a statistical risk factor for shunt failure (p = 0.0290) but not for shunt infection. There was no statistical relationship between shunt malfunction or infection and the CSF levels of red blood cells, white blood cells, protein, or glucose before shunt insertion. CONCLUSIONS Low-birth-weight premature infants with posthemorrhagic hydrocephalus have a high rate of shunt failure and infection. The authors did not find any association of shunt failure or infection with CSF cell count, protein level, or glucose level. Therefore, it may not be useful to base the timing of shunt insertion on CSF parameters.

A prospective comparative study of microscope-integrated intraoperative fluorescein and indocyanine videoangiography for clip ligation of complex cerebral aneurysms

OBJECT The authors prospectively analyzed 2 microscope-integrated videoangiography techniques using intravenous indocyanine green (ICG) and fluorescein for assessment of cerebral aneurysm obliteration and adjacent vessel patency. METHODS The authors prospectively enrolled 22 patients who underwent clip ligation of their aneurysm and used intraoperative videoangiography to assess obliteration of the aneurysmal sac and patency of the adjacent branching and perforating arteries. Patients underwent ICG videoangiography (ICG-VA) and the newly developed fluorescein videoangiography (FL-VA) using microscope-integrated fluorescence modules. Two independent observers compared the videoangiography recordings for value and quality to assess aneurysm exclusion and the patency of adjacent arteries. RESULTS All 22 patients first underwent FL-VA and then ICG-VA after clip application. In 7 cases (32%), FL-VA provided superior detail to assess perforating arteries (4 cases), distal branches (2 cases), and both (1 case); such detail was not readily available on ICG-VA. In 1 patient, ICG-VA offered better visualization of posterior communicating artery aneurysm occlusion than FL-VA because of staining artifact on the aneurysm dome from the adjacent tentorium. In 2 patients, FL-VA offered the needed advantage of real-time manipulation of the vessels and flow assessment by visualization through the operating microscope oculars. In 2 other cases, ICG-VA was more practical for repeat usage because of its more efficient clearance from the intravascular space. The ICG-VA image quality was often degraded at higher magnification in deep operative fields, partly due to chromatic aberration. Both ICG-VA and FL-VA afforded restricted views of vasculature based on the angle of surgical approach and obscuration by blood clot, aneurysm, or brain tissue. CONCLUSIONS Compared with ICG-VA, FL-VA can potentially provide an improved visualization of vasculature at high magnification in deep surgical fields. ICG-VA is more effective for repeated use during clip repositioning due to ICGs minimal vascular wall extravasation. Therefore, in certain cases, FL-VA may offer some advantages and play a complementary role along with ICG-VA in intraoperative fluorescence evaluation during microsurgical management of aneurysms.

Incidence, Epidemiology, and Treatment of Aneurysmal Subarachnoid Hemorrhage in 12 Midwest Communities

Only 8 studies have investigated the incidence and epidemiology of aneurysmal subarachnoid hemorrhage (aSAH) in the United States. This is the first investigation in Indiana, which has some of the highest rates of tobacco smoking and obesity in the nation. The authors prospectively identified 441 consecutive patients with aSAH from 2005 to 2010 at 2 hospitals where the majority of cases are treated. Incidence calculations were based on US Census populations. Epidemiologic variables included demography; risk factors; Hunt and Hess scale; Fisher grade; number, location, and size of aneurysms; treatment type; and complications. Overall incidence was 21.8 per 100,000 population. Incidence was higher in women, increased with age, and did not vary by race. One third to half of patients were hypertensive and/or smoked cigarettes at the time of ictus. Variations by count were partially explained by Health Factor and Morbidity Rankings. Complications varied by treatment. These findings deviate from estimates that 6-16 per 100,000 people in the United States will develop aSAH and are double the incidence in a Minnesota population between 1945 and 1974. The results also deviate from the worldwide estimate of 9.0 aSAHs per 100,000 person-years. The predictive value of variations in Health Factor and Morbidity Rankings implicates the importance of future research on multivariate biopsychosocial causation of aSAH.

Treatment and Outcomes Among 102 Posterior Inferior Cerebellar Artery Aneurysms: A Comparison of Endovascular and Microsurgical Clip Ligation

BACKGROUND The vicinity of brainstem and cranial nerves as well as the limited operative working space make clip ligation of posterior inferior cerebellar artery (PICA) aneurysms challenging. The small caliber of the PICA and the broad neck often associated with these aneurysms also create challenges in preserving this artery during treatment. Few data exist to compare the 2 treatment approaches for aneurysms in this location. OBJECT To assess treatment outcomes for PICA aneurysms based on mode of management and anatomical location. METHODS A prospectively maintained database was queried for PICA aneurysms treated from 2000 through 2012. Patients were categorized on the basis of their aneurysms anatomical location, presentation status, treatment modality, and subsequent complications. Descriptive, univariate, and multivariate statistical analyses were performed. RESULTS A total of 113 PICA aneurysms were identified; 11 did not undergo treatment. Of the remaining 102 aneurysms, 77% were ruptured and 64% were treated microsurgically. In the ruptured group, patients with more proximally located aneurysms such as vertebral and proximal PICA aneurysms were more likely to experience hydrocephalus and cranial nerve deficits after treatment. Endovascular therapy was less likely to cause postoperative deficit or lead to a need for percutaneous endoscopic gastrostomy. Most importantly, discharge, 6-month, and 1-year outcomes were predicted based on presenting Hunt and Hess score and patients age, not aneurysm location or management mode. CONCLUSIONS PICA aneurysms are challenging and require a multimodality treatment paradigm. Although microsurgery is associated with more short-term postoperative complications, presenting grade and patients age remain the primary predictors of long-term outcome.

The use of intraoperative navigation for percutaneous procedures at the skull base including a difficult-to-access foramen ovale.

BACKGROUND: We describe the use of an intraoperative CT scan obtained using the Medtronic O-arm (Littleton, Massachusetts) for image-guided cannulation of the foramen ovale not previously accessible with the use of fluoroscopy alone. Unlike previously described procedures, this technique does not require placement of an invasive head clamp and may be used with an awake patient. OBJECTIVE: To describe the use of intraoperative neuronavigation for accessing skull base foramina and, specifically, cannulating of the foramen ovale during percutaneous rhizotomy procedures using an intraoperative image guidance CT scanner (Medtronic O-arm, Littleton, Massachusetts). METHODS: A noninvasive Landmark Fess Strap attached to a spine reference frame was applied to the heads of 4 patients who harbored a difficult-to-access foramen ovale. An intraoperative HD3D skull base scan using a Medtronic O-arm was obtained, and Synergy Spine software was used to create 3D reconstructions of the skull base. Using image guidance, we navigated the needle to percutaneously access the foramen ovale by the use of a single tract for successful completion of balloon compression of the trigeminal nerve. RESULTS: All 4 patients (3 females and 1 male; ages 65-75) underwent the procedure with no complications. CONCLUSION: Based on our experience, neuronavigation with the use of intraoperative O-arm CT imaging is useful during these cases.

Investigator ratings of ADHD symptoms during a randomized, placebo-controlled trial of atomoxetine: a comparison of parents and teachers as informants.

This study compared investigator ratings of ADHD symptoms based on interviews with parents and teachers during a doubleblind, placebo-controlled study of atomoxetine. Investigators completed the ADHD Rating Scale: Investigator (ADHDRS-I) based on separate semistructured interviews with the primary caretaker and teacher of the participant. Interviews were conducted at Visits 2 to 7 during a double-blind treatment protocol comparing atomoxetine (N= 10) and placebo (N= 6). Both parent and teacher-based ratings were sensitive to change in ADHD symptoms with atomoxetine treatment. Parent-based assessment differentiated significantly between treatment with atomoxetine and placebo, whereas teacher-based assessment was less sensitive to change. Parents and teachers showed good agreement on change in ADHDRS-I scores. Investigator ratings based on parent- and teacher-report were sensitive to change in symptoms of ADHD during treatment with atomoxetine. Despite good agreement between parent- and teacher-based ratings of symptom change, parent-based ADHD symptom ratings are more sensitive to symptom change.

Dural arteriovenous fistulas presenting with brainstem dysfunction: diagnosis and surgical treatment

A cerebral dural arteriovenous fistula (DAVF) is an acquired abnormal arterial-to-venous connection within the leaves of the intracranial dura with a wide range of clinical presentations and natural history. The Cognard classification correlates venous drainage patterns with neurological course, identifying 5 DAVF types with increasing rates of symptomatic presentation. A spinal DAVF occurs when a radicular artery makes a direct anomalous shunt with a radicular vein within the dural leaflets of the nerve root sleeve. A cervical DAVF is a rare entity, as most spinal DAVFs present as thoracolumbar lesions with myelopathy. In this paper the authors present 2 patients presenting initially with brainstem dysfunction rather than myelopathy secondary to craniocervical DAVF. The literature is then reviewed for similar rare aggressive DAVFs at the craniocervical junction presenting with brainstem symptomatology.

Surgical Treatment of 127 Anterior Choroidal Artery Aneurysms A Cohort Study of Resultant Ischemic Complications

BACKGROUND The anterior choroidal artery (AChA) supplies important areas of the nervous system, particularly the posterior limb of the internal capsule and optic radiation. Treatment of AChA aneurysms poses particular challenges because of the complex anatomy of the aneurysm associated with the relatively small diameter of AChAs, making preservation of the parent vessel during clip ligation or endosaccular coiling challenging. OBJECTIVE To investigate the incidence and features of ischemia in treatment of AChA aneurysms. METHODS A prospectively maintained database of patients who underwent treatment of aneurysms from 1985 to 2011 was queried to find patients with AChA aneurysms. Age, sex, Hunt and Hess grade, treatment modality, and complications were analyzed by use of the unpaired Student t test and Fisher exact test. RESULTS One hundred twenty-two patients harbored 127 AChA aneurysms, and 67% (82 of 122) had multiple aneurysms. Treatment included 112 microsurgical clip ligations, 8 endosaccular coil embolizations, 5 aneurysmal wrappings, and 2 surgical explorations. Complications developed in 53% (67 of 127) of AChA aneurysms. Postoperative ischemia occurred in 12% (15 of 127) of treated aneurysms. The number of temporary clip applications was most closely associated with postoperative ischemia. Glasgow Outcome Scale scores of 4 or 5 were obtained by 78% at discharge, 89% at 6 months, and 85% at 1 year. CONCLUSION The ischemic complication rate from surgical treatment of AChA aneurysms is most closely associated with higher frequency of temporary clip applications for proximal control and may be lower than previously reported. Supplementary intraoperative tools and limitation of vessel manipulation should be used to improve outcomes.

Posterior interhemispheric transfalcine transprecuneus approach for microsurgical resection of periatrial lesions: indications, technique, and outcomes.

OBJECT Surgical exposure of the peritrigonal or periatrial region has been challenging due to the depth of the region and overlying important functional cortices and white matter tracts. The authors demonstrate the operative feasibility of a contralateral posterior interhemispheric transfalcine transprecuneus approach (PITTA) to this region and present a series of patients treated via this operative route. METHODS Fourteen consecutive patients underwent the PITTA and were included in this study. Pre- and postoperative clinical and radiological data points were retrospectively collected. Complications and extent of resection were reviewed. RESULTS The mean age of patients at the time of surgery was 39 years (range 11-64 years). Six of the 14 patients were female. The mean duration of follow-up was 4.6 months (range 0.5-19.6 months). Pathology included 6 arteriovenous malformations, 4 gliomas, 2 meningiomas, 1 metastatic lesion, and 1 gray matter heterotopia. Based on the results shown on postoperative MRI, 1 lesion (7%) was intentionally subtotally resected, but ≥ 95% resection was achieved in all others (93%) and gross-total resection was accomplished in 7 (54%) of 13. One patient (7%) experienced a temporary approach-related complication. At last follow-up, 1 patient (7%) had died due to complications of his underlying malignancy unrelated to his cranial surgery, 2 (14%) demonstrated a Glasgow Outcome Scale (GOS) score of 4, and 11 (79%) manifested a GOS score of 5. CONCLUSIONS Based on this patient series, the contralateral PITTA potentially offers numerous advantages, including a wider, safer operative corridor, minimal need for ipsilateral brain manipulation, and better intraoperative navigation and working angles.

Blood Supply to the human spinal cord: Part II. Imaging and pathology

The blood supply of the spinal cord is a complex system based on multilevel sources and anastomoses. Diseases often affect this vascular supply and imaging has been developed that better investigates these structures. The authors review the literature regarding pathology and imaging modalities for the blood supply of the spinal cord. Knowledge of the disease processes and imaging modalities used to investigate these arterial lesions of the spinal cord will assist the clinician when treating patients with spinal cord lesions. Clin. Anat. 28:65–74, 2015.