Charles Kulwin

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.

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.

Diagnosis and evaluation of intracranial arteriovenous malformations

Background: Ideal management of intracranial arteriovenous malformations (AVMs) remains poorly defined. Decisions regarding management of AVMs are based on the expected natural history of the lesion and risk prediction for peritreatment morbidity. Microsurgical resection, stereotactic radiosurgery, and endovascular embolization alone or in combination are all viable treatment options, each with different risks. The authors attempt to clarify the existing literatures understanding of the natural history of intracranial AVMs, and risk-assessment grading scales for each of the three treatment modalities. Methods: The authors conducted a literature review of the existing AVM natural history studies and studies that clarify the utility of existing grading scales available for the assessment of peritreatment risk for all three treatment modalities. Results: The authors systematically outline the diagnosis and evaluation of patients with intracranial AVMs and clarify estimation of the expected natural history and predicted risk of treatment for intracranial AVMs. Conclusion: AVMs are a heterogenous pathology with three different options for treatment. Accurate assessment of risk of observation and risk of treatment is essential for achieving the best outcome for each patient.

Endovascular and microsurgical treatment of cerebral arteriovenous malformations: Current recommendations

Background: Cerebral arteriovenous malformations (AVMs) can be a heterogeneous pathological entity whose management requires a complex decision-making process due to the risks associated with their treatment and natural history. Despite the recently published conclusions of the aborted Randomized Trial of Brain Unruptured AVMs (ARUBA) trial, the authors of this article believe multimodality intervention in general and microsurgical resection in particular continue to play a major role in the management of carefully selected ruptured or unruptured AVMs. Methods: The authors provide an overview of their methodology for endovascular intervention and microsurgical resection and share their technical nuances for successful embolization and microsurgical resection of AVMs with special emphasis on complication avoidance. Results: The authors have achieved successful outcomes in embolization and resection of cerebral AVMs when using their methodology. Conclusions: These lesions are among the most technically difficult pathological entities handled by the cerebrovascular specialist, and an overview of technical concepts to help systematize this challenging and variable endeavor can improve the safety of their treatment.

Radiographic and clinical outcome of syringomyelia in patients treated for tethered cord syndrome without other significant imaging abnormalities

OBJECT The surgical management of patients with symptoms of tethered cord syndrome (TCS) who lack significant radiographic abnormalities is controversial. One potential MRI marker for TCS is a spinal cord syrinx or syringomyelia. Alternatively, a syrinx may be a benign and incidental finding. In this report the authors evaluated a highly selected cohort of patients with symptoms of TCS with minimal radiographic abnormalities other than syringomyelia. They analyzed clinical and radiographic outcomes after tethered cord release (TCR). METHODS A retrospective review of data from 16 children who met the study inclusion criteria was performed. All patients had been surgically treated at Riley Hospital for Children in Indianapolis, Indiana, between 2006 and 2011. All children had clinical symptoms of TCS as well as available pre- and postoperative MRI data. RESULTS The most common presentation (12 [75%] of 16 patients) was urinary dysfunction, defined as symptoms of urgency or incontinence with abnormal urodynamic studies. Clinical follow-up data were available in 11 of these 12 patients. All 11 had improvement in symptoms at an average follow-up of 17 months. Seven (87.5%) of 8 patients presenting with back or leg pain had improvement. Three patients had progressive scoliosis; 2 had stabilization of the curve or mild improvement, and 1 patient had worsening deformity. Radiographic follow-up data were obtained an average of 14.5 months after surgery. Twelve patients (75%) had stable syringomyelia after TCR. Four patients showed improvement, with 2 having complete radiographic resolution. CONCLUSIONS Highly selected patients with symptoms of TCS did very well clinically. Patients with abnormal urodynamic studies, pain, and gait disturbances showed a high rate of symptomatic improvement. However, a smaller percentage of patients had radiographic improvement of the syrinx. Therefore, the authors suggest that the decision to perform TCR should be based on clinical symptoms in this population. Symptomatic improvement was not necessarily related to radiographic resolution of the syrinx.

Temporal and optic pathway pilomyxoid astrocytoma mimicking dural-based lesion: Case report and review of the literature

Pilomyxoid astrocytomas (PMAs) are low-grade tumors that share many common traits with pilocytic astrocytomas. However, PMAs have a more worrisome clinical course, with a higher recurrence rate, lower survival rate, and higher risk of leptomeningeal spread compared to pilocytic tumors. These tumors tend to occur in younger children and are typically located in the area of the optic chiasm or hypothalamus. There are few studies examining the radiographic appearance of these lesions. In this case report, the authors present an unusual radiographic appearance of a PMA in an 11-year-old child. Preoperative images suggested a dural-based, homogenously enhancing lesion coupled with an enlarged optic nerve. Surgery revealed an intraparenchymal lesion of the right temporal lobe. There was hyperintensity on T2 MRI sequences, suggesting infiltration of the tumor along the optic tracts.

Neuroprotective effect of dexmedetomidine in a murine model of traumatic brain injury

No FDA approved pharmacological therapy is available that would reduce cell death following traumatic brain injury (TBI). Dexmedetomidine (Dex) is a highly selective agonist of alpha-2 adrenergic receptors and has demonstrated neuroprotective effects in hippocampal slice cultures undergoing direct impact. However, no one has tested whether Dex, in addition to its sedative action, has neuroprotective effects in an animal model of TBI. Thus, in the present study, we investigated the effects of Dex on an animal model of TBI. Mice received different doses of Dex (1, 10, or 100 µg/kg bodyweight, n = 10 each group) or saline as control at 1 hour and 12 hours following TBI. The mice treated with Dex lost less cortical tissue than the control mice. Further analysis found that Dex treatment reduced cell death in the cortex and the hippocampus measured by Fluoro-Jade B (FJB) staining, prevented axonal degeneration detected by immunostaining with antibody against β-amyloid precursor protein (β-APP), and protected synapses from elimination with synaptophysin staining. Taken together, in an in vivo murine model of TBI, Dex at the dose of 100 µg/kg not only prevented tissue lesion and cell death, but also reduced axonal injury and synaptic degeneration caused by TBI.

Endoscopic endonasal transplanum transtuberculum resection of a large solid choroid plexus papilloma of the third ventricle

Choroid plexus papilloma (CPP) is a highly vascular solid or mixed solid-cystic tumor. Previously described resection techniques for the more common solid CPP in the third ventricle have all been through the transcranial route. The authors review the literature and describe a patient who, to their knowledge, is the first successful resection of a large, completely solid CPP of the third ventricle through an entirely endoscopic, extended transphenoidal approach. Using modern neuroendoscopic methods and closure techniques, a gross total resection was accomplished and a successful closure without postoperative cerebrospinal fluid leak was achieved despite the presence of preoperative hydrocephalus. For appropriately selected lesions, an extended endonasal skull base resection can be performed successfully for vascular tumors despite the presence of preoperative hydrocephalus.

Aneurysmal acute subdural hemorrhage: Prognostic factors associated with treatment

Acute subdural hematoma is an uncommon presentation of aneurysmal hemorrhage that has been identified as a poor prognostic sign. Current series are small, have short follow-up, or were collected over a long period during which treatment evolved. To evaluate prognostic factors, we analyzed a large modern series of aneurysmal subdural hematoma (aSDH) with long-term follow-up. A prospectively maintained database was queried for patients presenting with aSDH from 2001-2013. Thirty patients met the study criteria. Statistical analysis was performed with unpaired t-test or Fishers exact test. Aneurysm treatment involved open clipping (n=18), endosaccular coiling (n=8), both (n=1), or no treatment (n=3). Good Glasgow Outcome Scale score at discharge was present in 20% and increased to 40% at 6-12 months postoperatively. Good clinical presentation was associated with good final outcome in 75%, whereas poor clinical presentation correlated with good outcome in 30%. Good outcome correlated with younger age (p=0.04), smaller aneurysm (p=0.04), and lower Hunt-Hess score (HH) at intervention (p=0.04). Favorable outcome did not correlate with sex, race, presence of subarachnoid or intraparenchymal hemorrhage, size or laterality of hemorrhage, midline shift, aneurysm treatment modality, or HH at admission (p>0.15). There was no difference between good and poor outcomes in terms of time to treatment or hematoma evacuation. Poor clinical presentation may be exaggerated by mass effect of hematoma; aggressive treatment is not futile. Presenting neurological status, age, and aneurysm size are predictors of outcome, while laterality and size of hematoma and extent of midline shift are not, suggesting that clinical status is more important than radiographic findings.

Ventriculogallbladder shunt fracture: bile peritonitis.

A 9-year-old girl presented with worsening lower abdominal pain and emesis of 10 hours’ duration. She had a history of a ventriculogallbladder shunt (VGBS) placed 18 months after failure of peritoneal shunting for posthemorrhagic hydrocephalus. Examination revealed a diffusely tender abdomen; she was at her neurological baseline. Serology demonstrated borderline leukocytosis without hepatobiliary abnormalities. A radiographic shunt series (Fig. 1) showed a fracture of the catheter just below the valve. The catheter below the fracture site had retracted into the lower abdomen. The distal catheter remained in place in the gallbladder dome. CT of the abdomen/pelvis (Fig. 2) revealed a moderate amount of free fluid with peritoneal thickening consistent with peritonitis. The patient was taken urgently to the operating room. Laparoscopy revealed intraperitoneal bilious fluid. The gallbladder was noted to be extensively adherent to the surrounding tissue, so the catheter was ligated just outside the gallbladder due to concern for complication with cholecystectomy or catheter removal (Fig. 3). The proximal ventricular shunt and valve were explored and noted to be working well; a distal atrial catheter was placed. The patient was discharged home on postoperative Day 4. At 3-month followup she showed no signs or symptoms of shunt malfunction. Described VGBS-specific malfunctions include bilious reflux resulting in ventriculitis 2 or meningitis 1 and cholecystic complications including atony, biliary tract infection, and cholecystitis. 3,4