Medically induced CSF rhinorrhea following treatment of macroprolactinoma: case series and literature review.

PURPOSE: Although several reports have addressed cerebrospinal fluid (CSF) rhinorrhea following dopamine agonist (DA) therapy of macroprolactinomas, further study is warranted for this relatively uncommon entity. Toward this aim, our retrospective series and review of literature further clarifies recommendations in treatment of this rare problem. METHODS: We retrospectively reviewed all macroprolactinoma cases in our hospital for a 15-year period. Our systematic search of PubMed identified original articles and reviews of all macroprolactinoma cases with an associated medication-induced CSF leak. RESULTS: Five patients with drug-induced CSF leak were identified; four of these patients received cabergoline therapy an average of 6 weeks before the onset of rhinorrhea and then underwent surgical repair of the CSF leak. Of 35 published studies included, we identified 60 patients with medication-induced CSF leak. Medical therapy included bromocriptine in 34 patients, cabergoline in 21 patients, and use of both DAs in two patients. Three cases did include complete diagnostic and treatment data. Median time from initiation of the DA treatment to occurrence of rhinorrhea was 6 weeks. For CSF rhinorrhea, 49 patients underwent surgical repair (38 by the transnasal approach) and seven patients were treated nonoperatively. CONCLUSION: Baseline skull base erosion in macroprolactinomas in combination with subsequent tumor shrinkage induced by DA therapy may result in spontaneous CSF rhinorrhea. Therefore, such patients should be advised about and monitored for this potential setback. Once CSF leak is diagnosed, prompt treatment must be carried out to avoid infectious complications. Transnasal surgery appears the most effective therapeutic approach.

Microsurgery of Meningiomas Involving the Superior Sagittal Sinus.

Meningiomas involving major dural sinuses can be difficult to resect without proper handling of the sinus. In young patients, a gross total resection should be attempted when feasible. A 24-year-old man presented with headaches, progressive left-sided weakness, and partial motor seizures. He was found to have a parasagittal meningioma in front of the motor cortex that invaded the superior sagittal sinus (SSS). The sinus was still patent, and the walls were preserved. Thus a gross total resection was achieved with primary suturing of the sinus, followed by reinforcement with an AnastoClip GC. Videos 1-3 details the separation of the tumor from the convexity veins and the cortex, removal of the tumor from the SSS, and reconstruction of the SSS. Gross total resection of meningiomas involving the SSS is achievable without sacrificing the sinus when planned correctly and methodically. The patient consented for the procedure and to the publication of these images.

Microsurgical Resection of Spinal Arteriovenous Malformation with Clipping of Anterior Spinal Artery Aneurysm.

Spinal cord arteriovenous malformations (AVMs) are rare and usually present in younger patients. We present the case of a 76-year-old woman with a 2-year history of unsteady gait. She presented to us with sudden-onset thoracic pain, numbness, and weakness in both legs. She was found to have urinary retention, dissociative pain loss in the left leg, and weakness involving the right leg. Magnetic resonance imaging demonstrated an intramedullary spinal AVM with subarachnoid hemorrhage and cord edema. The spinal angiogram detailed the architecture of the AVM and revealed a flow-related aneurysm in the anterior spinal artery. The patient underwent T8-T11 laminoplasty with a T10 transpedicular approach to allow for ventral exposure of the cord. Initially, a microsurgical clipping of the aneurysm was performed, followed by a pial resection of the AVM. Postoperatively, the patient recovered her bladder control and motor function. She is now able to walk with a walker due to impaired proprioception. Videos 1-4 detail the key steps and techniques for safe clipping and resection.

Novel Use of Robotically Harvested Internal Thoracic Artery in High-Flow Cerebral Bypass.

Mesenchymal tumors of the head and neck can lead to tumor-induced osteopeni, necessitating a biochemical cure to alleviate associated symptoms. We present a case of a 40-year-old man who presented with diffuse pain and wheelchair dependency secondary to a skull base mesenchymal tumor producing tumor-induced osteopeni. The tumor involved the cavernous sinus, infratemporal fossa, and middle cranial fossa. The patient failed the balloon occlusion test. Additionally, the patient consented to the procedure. Cerebral revascularization was performed using a robotically harvested internal thoracic artery because of the patient's short radial arteries and history of chronic superficial and deep vein thrombosis. After the common carotid artery-internal thoracic artery-M2 bypass, the patient underwent endovascular embolization of the external carotid artery feeders and occlusion of the cavernous external carotid artery. Several days later, the patient underwent a gross total resection via endoscopic assisted microsurgery. The residual biochemical disease was then addressed via supplemental radiosurgery. The patient's clinical outcome was favorable, with regained ambulatory function and resolution of initial symptoms. Unfortunately, he developed left optic neuropathy due to the embolization of the external carotid artery feeders.

Minimally Invasive Double-Barrel Superficial Temporal Artery-Middle Cerebral Artery Bypass.

Superficial temporal artery (STA)-middle cerebral artery (MCA) bypass is used to augment flow in various cases. We present a patient with a refractory right MCA transient ischemic attack and a minor stroke. He was perfusion dependent. A computed tomography perfusion with acetazolamide challenge showed hypoperfusion in the superior and inferior trunk of the MCA on the right side. We thus used the frontal and parietal branches of the STA to revascularize both territories. This was done via a small single incision and craniotomy. We present here the details of the techniques and surgical nuances (Video 1). The patient consented to the procedure and to the publication of his or her own images.

Patient selection for revascularization procedures in adult Moyamoya disease based on dynamic perfusion computerized tomography with acetazolamide challenge (PCTA).

The usefulness of dynamic perfusion computerized tomography for early diagnosis of stroke is well established. However, limited data exists to assess the value of PCT in the evaluation of patients with chronic cerebral ischemia. The purpose of the study was to assess the utility of perfusion computerized tomography with acetazolamide challenge (PCTA) in the evaluation of cerebral perfusion and cerebrovascular reserve (CVR) in adult Moyamoya patients. From 2005-2008, 41 patients with Moyamoya were scrutinized by PCTA. Of these, 22 patients (12 females, ten males, mean age 41 years) with ischemic symptoms from Moyamoya disease were found to have no response or decreased cerebrovascular flow post-acetazolamide indicating compromised CVR. Eight had bilateral symptoms. Based on matching symptoms and decreased CVR on PCTA, those 22 patients underwent 30 superficial temporal artery-to-middle cerebral artery (STA-MCA) by-pass (eight with bilateral abnormal PCTA had bilateral STA-MCA by-pass). After a mean follow-up of 14 months (range, 3-36 months), no new strokes or symptoms were reported. Graft patency, as documented by postoperative computerized tomography angiography at a mean 12 weeks after surgery was 100%. Eight patients had postoperative PCTA documenting improved CVR after STA-MCA by-pass. At latest follow-up, none of the 19 patients with PCTA findings suggestive of normal CVR had any ischemic symptoms. CVR testing by means of PCTA may have a key role in patient selection for revascularization surgery and postoperative follow-up. These promising results warrant further testing of the technique.

Use of radial artery grafts in extracranial-intracranial revascularization procedures.

Cerebral revascularization procedures have been used in the clinical management of actual or threatened cerebral ischemic states and unclippable cerebral aneurysms. An alternative to a low-flow bypass graft (for example, with the superficial temporal artery) is the use of high-flow grafts created using the saphenous vein (SV) or radial artery (RA). These high-flow grafts are particularly useful when otherwise adequate collateral flow is insufficient to enable sacrifice of the parent vessel without the risk of cerebral ischemia. In their clinical series of 13 patients who underwent high-flow bypass with an RA graft, the authors describe 8 women and 5 men whose ages ranged from 44 to 69 years (mean 57.84 +/- 9.05 years). Indications for RA graft bypass were unclippable aneurysms in 10 patients and occlusive cerebrovascular disease in 3 patients. The authors review the properties of the 2 most common conduits, the SV and RA grafts. They present the technique of high-flow extracranial-intracranial bypass produced using RA grafts in the management of occlusive atherosclerotic disease and complex intracranial aneurysms that are not otherwise amenable to either clip ligation or coil occlusion.

Genetic Determinants of Cerebral Arterial Adaptation to Flow-loading.

BACKGROUND: In animal models, flow-loading is a necessary and sufficient hemodynamic factor to express the Cerebral Aneurysm (CA) phenotype. Using a rat model, this study characterizes the molecular events that comprise the cerebral arterial response to flow-loading and reveals their significance relating to the CA phenotype. OBJECTIVE: To characterize the molecular events that underlie expansive remodeling of cerebral arteries in two genetically distinct inbred rat strains with differential susceptibility to flow-dependent cerebrovascular pathology. METHODS: Thirty-two rats underwent bilateral common carotid artery ligation (BCL) (n=16) or Sham Surgery (SS) (n=16). Nineteen days later, vertebrobasilar arteries were harvested, histologically examined and analyzed for mRNA and protein expression. Flow-induced changes in histology, mRNA and protein expression were compared between BCL and SS rats. Differences between aneurysm-prone (Long Evans, LE) and resistant (Brown Norway, BN) strains were evaluated. RESULTS: Basilar Artery (BA) medial thickness/luminal diameter ratio was significantly reduced in BCL rats, without significant differences between LE (2.02 fold) and BN (1.94 fold) rats. BCL significantly altered BA expression of mRNA and protein but did not affect blood pressure. Eight genes showed similarly large flow-induced expression changes in LE and BN rats. Twenty-six flow responsive genes showed differences in flow-induced expression between LE and BN rats. The Cthrc1, Gsta3, Tgfb3, Ldha, Myo1d, Ermn, PTHrp, Rgs16 and TRCCP genes showed the strongest flow responsive expression, with the largest difference between LE and BN rats. CONCLUSIONS: Our study reveals specific molecular biological responses involved in flow-induced expansive remodeling of cerebral arteries that may influence differential expression of flowdependent cerebrovascular pathology.

Single-stage total C-2 intralesional spondylectomy for chordoma with three-column reconstruction. Technical note.

Chordomas are locally invasive, malignant bone tumors that rarely occur in the cervical spine. En bloc resection or even fully resecting the tumor along its margin offers improved patient survival and a potential disease cure. Complete resection of tumors involving the upper cervical vertebrae requires a combined anterior-posterior approach but is complicated by the presence of vertebral arteries (VAs). In addition, reconstruction of the postresection defect may be prone to failure. The authors present a case of a chordoma involving the axis that was treated using a single-stage total intralesional C-2 spondylectomy with preservation of both VAs because the patient did not tolerate a preoperative occlusion test. A three-column reconstruction technique is also presented.

The Interlenticulostriate Approach to Very High-Riding Distal Basilar Trunk Aneurysms.

BACKGROUND: Most high-riding distal basilar trunk aneurysms can be surgically approached via the transsylvian route and its orbitozygomatic variant. However, on rare occasions, the basilar bifurcation may be unusually high and an approach above the carotid terminus may be required. OBJECTIVE: In this cadaveric study, we sought to determine the feasibility and exposure limits of the interlenticulostriate approach (ILSA). METHODS: A standard transsylvian approach was performed in 10 cerebral hemispheres of 5 formalin-fixed, silicone-injected cadaver heads. The interpeduncular cistern was exposed via the opticocarotid window, carotid-oculomotor window, and supracarotid ILSA window. The latter was measured and an aneurysm clip or ventriculostomy stylet was placed as high as possible through each corridor. Using noncontrast 3-D rotational angiography, clip/stylet positions were measured relative to the dorsum sellae. RESULTS: ILSA provided a 9.4 × 4.6 mm mean surgical corridor, just enough room for a standard clip applier. This space was limited by the carotid bifurcation inferiorly, the lenticulostriate arteries medially and laterally, and the optic tract superiorly. There was no difference between opticocarotid and carotid-oculomotor windows, in terms of clip position (+8.9 vs +8.6 mm, respectively; P = .78). In contrast, ILSA provided significantly improved superior exposure, compared with either approaches (mean stylet position: +14.3 mm; P = .005). The exposure benefit afforded by ILSA was consistent across all 10 hemispheres, ranging from +2.5 to +8 mm. CONCLUSION: For high-riding distal basilar trunk aneurysms that cannot be reached via the frontotemporal orbitozygomatic approach, ILSA can provide a viable route of access. Vascular neurosurgeons should be familiarized with this approach.

Vertebral column subtraction osteotomy for recurrent tethered cord syndrome in adults: a cadaveric study.

OBJECT: The standard treatment for lumbosacral tethered cord syndrome (TCS) in adults is surgical detethering. In patients with recurrent TCS, additional detethering operations are associated with increased risk of complications and subsequent scar formation. The authors studied the effect of undertaking a vertebral column subtraction osteotomy (VCSO) at the thoracolumbar junction to shorten the vertebral column and reduce neural element tension. METHODS: A model of TCS, developed in fresh-frozen human cadavers, was evaluated in three experiments. In Experiment 1, VCSO of 20 to 25 mm was performed at the T11-12 level. The vertebral column was sequentially shortened and the reduction in tension was measured separately in the terminal filum and the L-1 to S-3 or S-4 nerve roots. In Experiments 2 and 3 the reduction in tension was measured in the spinal cord after a VCSO and after simulating a traditional detethering operation. Vertebral column shortening produced tension reduction in all experiments. Tension decreased to less than 0.6 g in the terminal filum, L1-S3/4 nerve roots, and spinal cord after closure of a 20- to 25-mm VCSO. The mean +/- standard deviation of the deltatension/deltadistance was -0.242 +/- 0.019 g/mm for the terminal filum, -0.246 +/- 0.019 g/mm for the lumbar nerve roots, and -0.216 +/- 0.040 g/mm for the sacral nerve roots. A simulated traditional detethering operation required significant neural element release (detethering) to achieve spinal cord tension reduction equivalent to VCSO. CONCLUSIONS: A VCSO significantly reduced neural tension at the thoracolumbar junction. This novel procedure may provide an alternative to traditional surgical detethering when scarring is excessive and the risk of complications and retethering are high.

Changes in computed tomography perfusion parameters after superficial temporal artery to middle cerebral artery bypass: an analysis of 29 cases.

Introduction Analysis of computed tomography perfusion (CTP) studies before and after superficial temporal artery to middle cerebral artery (STA-MCA) bypass is warranted to better understand cerebral steno-occlusive pathology. Methods Retrospective review was performed of STA-MCA bypass patients with steno-occlusive disease with CTP before and after surgery. CTP parameters were evaluated for change after STA-MCA bypass. Results A total of 29 hemispheres were bypassed in 23 patients. After STA-MCA bypass, mean transit time (MTT) and time to peak (TTP) improved. When analyzed as a ratio to the contralateral hemisphere, MTT, TTP, and cerebral blood flow (CBF) improved. There was no effect of gender, double vessel versus single vessel bypass, or time until postoperative CTP study to changes in CTP parameters after bypass. Conclusions Blood flow augmentation after STA-MCA bypass may best be assessed by CTP using baseline MTT or TTP and ratios of MTT, TTP, or CBF to the contralateral hemisphere. The failure of cerebrovascular reserve to improve after cerebral bypass may indicate irreversible loss of autoregulation with chronic cerebral vasodilation or the inability of CTP to detect these improvements.

Trends in the management of adult moyamoya disease in the United States: results of a nationwide survey.

BACKGROUND: Moyamoya disease is a rare, progressive, steno-occlusive disease of the distal branches of the carotid arteries associated with the development of a profuse basal collateral vascular network. In the United States, the disease occurs sporadically and literature on the topic in limited. With data lacking relative to moyamoya epidemiology and management, we report our survey results among a sample of neurovascular surgeons. METHODS: A 16-question survey was sent as a hyperlink by electronic mail to 46 vascular neurosurgery centers and physicians who have published on this topic. Data included patient demographics, referral patterns, treatment, and follow-up. RESULTS: Response rate was 70%. Of 32 respondents, 72% evaluated 10 or fewer adults per year, usually referred by a neurologist within their referral pattern. Fifteen (47%) respondents reported that the disease had a bilateral occurrence between 50% and 75% of the time. Most respondents (88%) reported that fewer than 25% of their patients had a previous surgery for the disease. Symptomatology (91%) was the criterion to recommend surgery. Nineteen (59%) respondents regularly assessed cerebrovascular reserve by the addition of acetazolamide challenge to their imaging method of choice, typically single photon emission computed tomography. Treatment was antiplatelets (55%) in asymptomatic adults and superficial temporal artery-to-middle cerebral artery bypass for >75% of symptomatic patients, as assessed by 48% of respondents. Yearly follow-up included cerebral angiography for both superficial temporal artery-to-middle cerebral artery bypass and indirect revascularization. CONCLUSIONS: Our survey results quantify epidemiologic trends of moyamoya disease in the United States. Finding a lack of consensus in management strategies, we conclude that collaborative efforts may help to create guidelines for the management of this puzzling entity.