Troy D. Payner

Acquired chiari malformations : Incidence, diagnosis, and management

The acquired descent of the cerebellar tonsils radiographically indistinguishable from Chiari I malformations has been previously reported. The relationship between lumbar shunting procedures for hydrocephalus and symptomatic Chiari malformations has been established. We report the cases of 10 children with lumboperitoneal shunts in whom previous radiographic studies had confirmed a normal hindbrain configuration. Seven of the 10 patients acquired tonsillar descent into the foramen magnum, detected by magnetic resonance imaging, whereas the others remained normal. Four of seven patients were symptomatic; two underwent the removal of the lumboperitoneal shunt and conversion to a ventriculoperitoneal shunt, and two underwent posterior fossa decompression. Further magnetic resonance imaging revealed that one of the two patients who underwent conversion shows ascent of the cerebellar tonsils. All four patients became asymptomatic less than 6 months after treatment. In this article, we discuss seven cases of acquired Chiari malformations and the complete reversal of an acquired Chiari malformation after surgical treatment, as documented by magnetic resonance imaging. Cases of asymptomatic acquired Chiari malformations are reported, including those resulting from shunting for intracranial hypertension without hydrocephalus. We conclude that a craniospinal pressure gradient creates a potential for cerebellar tonsil descent and recommend that ventriculoperitoneal shunting be performed in children with communicating hydrocephalus to avoid this potential complication. We also recommend annual surveillance of the cervicomedullary junction in children with lumboperitoneal shunting. Finally, if symptomatic tonsillar descent occurs from lumbar shunting, a trial conversion to ventriculoperitoneal shunting may eliminate the need for posterior fossa decompression.

Analysis of Intraoperative Rupture in the Surgical Treatment of 1694 Saccular Aneurysms

OBJECTIVE:Intraoperative rupture (IOR) of an aneurysm is a known risk in the surgical management of intracranial aneurysms. The purpose of this study was to determine the incidence of IOR in a modern surgical series and to assess which factors bear upon it. METHODS:This study retrospectively examined 1269 patients with saccular aneurysms treated surgically between 1986 and 1998. Three vascular neurosurgeons performed 1435 operations on 1694 aneurysms. Multiple factors, including the magnitude and time of occurrence of IOR, aneurysm location, subarachnoid hemorrhage, timing of surgery, and use of temporary occlusion, were analyzed. RESULTS:There were 113 instances of IOR (7.9% per surgery; 6.7% per aneurysm; 8.9% per patient). If the 59 “minor leaks” are excluded (as in previously published reports), the incidence becomes 3.8% per surgery, 3.2% per aneurysm, and 4.3% per patient. Posteroinferior cerebellar artery and anterior and posterior communicating artery aneurysms were more liable to rupture intraoperatively. The IOR rate was greater in ruptured than unruptured aneurysms (10.7 versus 1.2%, P < 0.0001). There was a lower rate of IOR in operations using temporary arterial occlusion (3.1 versus 8.6%, P < 0.0001). The occurrence of IOR for early surgery was not significantly higher than for surgery performed more than 3 days after subarachnoid hemorrhage (11.1 versus 10.0%, P = 0.6234). CONCLUSION:The rate of significant IOR can be kept low. Aneurysm location, subarachnoid hemorrhage, and temporary arterial occlusion seem to be important factors affecting the incidence of IOR.

Acquired Chiari MalformationsIncidence, Diagnosis, and Management

ABSTRACTTHE ACQUIRED DESCENT of the cerebellar tonsils radiographically indistinguishable from Chiari I malformations has been previously reported. The relationship between lumbar shunting procedures for hydrocephalus and symptomatic Chiari malformations has been established. We report the cases of

Recurrence of hemifacial spasm after microvascular decompression

The success of medical and surgical treatment for hemifacial spasm, and involuntary paroxysmal unilateral contraction of the facial muscles, has been mixed. Although microvascular decompression has the greatest reported success, symptom recurrence affects many patients in whom treatment was initially successful. In this study, we report the results of 34 patients who underwent microvascular decompression of the facial nerve from 1976 to 1989 as well as review the literature concerning the incidence and timing of recurrence in more than 600 patients who underwent microvascular decompression. In this series, 94% of 34 patients had continuous relief of spasm after surgical treatment (mean duration, > 6 yr). Of those patients whose spasms were completely initially relieved, 10.3% developed some degree of recurrent spasm; however, no patient developed a recurrence after 24 months without spasm. Our review of the literature discloses that 86% of all recurrences occurred within 2 years of surgery. Patients who have no recurrence of symptoms 2 years after surgical treatment have only a 1% chance of developing recurrent hemifacial spasm. We also comment on possible causes of treatment failure and recurrence of hemifacial spasm after surgical treatment.

Results, outcomes, and follow-up of remnants in the treatment of ophthalmic aneurysms: a 16-year experience of a combined neurosurgical and endovascular team.

OBJECTIVEOphthalmic aneurysms present unique challenges to a vascular team. This study reviews the 16-year experience of a multidisciplinary neurovascular service in the treatment, complications, outcomes, and follow-up of patients with ophthalmic aneurysms from 1990 to 2005. METHODSA retrospective analysis of prospectively collected data of 134 patients with 157 ophthalmic aneurysms is presented. Subgroup analysis is performed based on treatment and clinical presentation of the patients. RESULTSClinical outcomes are reported using the Glasgow Outcome Scale. A “good” outcome is defined as a Glasgow Outcome Scale score of 4 or 5, and a “poor” outcome is defined as a Glasgow Outcome Scale score of 1 to 3. Outcome was related to patient age (P = 0.0002) and aneurysm size (P = 0.046). Outcomes for patients with ruptured aneurysms were related to hypertension (P < 0.0001) and clinical admission grade (P = 0.001). In patients with unruptured aneurysms, a good clinical outcome was noted in 103 (92.7%) of 111 patients at discharge and 83 (94.3%) of 88 patients at the time of the 1-year follow-up evaluation. Complete clipping was attained in 89 (79.5%) of 112 patients with angiographic follow-up. Patients with aneurysm remnants from both coiling and clipping had a low risk of regrowth, and there were no rehemorrhages. One of 25 patients with angiographic follow-up (average, 4.3 ± 4.1 years) after “complete” clipping showed recurrence of the aneurysm. CONCLUSIONDespite the difficulties presented by ophthalmic aneurysms, these lesions can be successfully managed by a multidisciplinary team. Imaging follow-up of patients is important, as there is a risk of aneurysm regrowth after either coiling or clipping.

Endovascular retrograde suction decompression as an adjunct to surgical treatment of ophthalmic aneurysms: analysis of risks and clinical outcomes.

OBJECTIVE Endovascular retrograde suction decompression with balloon occlusion of the internal carotid artery is a useful adjunct in the surgical treatment of ophthalmic aneurysms. This technique helps establish proximal control, facilitates intraoperative angiography, and may aid dissection by evacuating blood and softening the aneurysm. Although the technical aspects of this procedure have been described, the published data on its safety are scant. This study analyzed 2 groups of patients who underwent craniotomies for treatment of ophthalmic aneurysms, comparing a group who received suction decompression with a group who did not. METHODS A retrospective analysis of prospectively collected data on 118 craniotomies for ophthalmic aneurysms performed from 1990 to 2005 is presented. A group of 63 patients treated with endovascular suction decompression during surgery is compared with 55 patients who did not undergo this technique. RESULTS In our overall analysis of ophthalmic aneurysms, the clinical outcome was statistically related to aneurysm size (P = 0.046). The endovascular suction decompression group in this study had overall larger aneurysms (P < 0.0001) compared with the other group. There was no statistical difference between the 2 groups in rates of complications, stroke, new visual deficit, or death. The clinical outcomes were statistically similar at discharge and at 1 year. CONCLUSION Endovascular balloon occlusion and suction decompression did not increase the complication rate in a large cohort of craniotomy patients with ophthalmic aneurysms. This technique may be used to augment surgical capabilities without significantly increasing the operative risk.

Intraoperative monitoring of the vagus nerve during intracranial glossopharyngeal and upper vagal rhizotomy: technical note.

Intracranial section of the glossopharyngeal and upper vagal rootlets for the treatment of vagoglossopharyngeal neuralgia may cause dysphagia or vocal cord paralysis from injury to the motor vagal rootlets in 10% to 20% of cases. To minimize this complication, we recently applied a technique of intraoperative monitoring of the vagus nerve (previously described by Lipton and McCaffery to monitor the recurrent laryngeal nerve during thyroid surgery) in a patient undergoing intracranial rhizotomy for vagoglossopharyngeal neuralgia. By inserting an electrode in the ipsilateral false vocal cord and stimulating the rostral vagal rootlets intraoperatively under general anesthesia, we could differentiate the rostral vagal motor rootlets from the sensory rootlets. In this patient, the technique allowed us to preserve a rostral vagal rootlet, which if sectioned, could have caused dysphagia or vocal cord paralysis. We conclude that intraoperative monitoring of the rostral vagal rootlets is an important technique to minimize complications of upper vagal rhizotomy.

Dural Cavernous Angiomas Outside the Middle Cranial Fossa

Cavernous angiomas of the dura mater are clinically and radiographically distinct from parenchymal cavernous angiomas. In this report, we present two cases of dural cavernous angiomas located outside the middle cranial fossa. The first patient is a 36-year-old woman with two dural cavernous angiomas, including one that enlarged during a 2-year period of observation. The second patient is a 33-year-old man with medically intractable seizures from a dural cavernous angioma of the convexity, which was discovered at autopsy. From our experience and a review of the literature, we have identified two groups of dural cavernous angiomas that differ in incidence, natural history, and surgical management. Most dural cavernous angiomas arise from the middle fossa; in contrast, only 15 cases of dural cavernous angiomas outside the middle fossa have been reported. Those in the middle fossa are more clinically aggressive and more difficult to resect surgically, because they grow toward the cavernous sinus and the parasellar region. Most patients with dural cavernous angiomas outside the middle fossa present with headaches, whereas those patients with dural cavernous angiomas in the middle fossa present with ocular signs, visual field defects, endocrinopathy, and trigeminal symptoms. Radiographically, both of the angiomas resemble meningiomas. Because of their intimate association with the cavernous sinus, surgical resection of middle fossa cavernous angiomas often is incomplete and may require postoperative radiosurgery to control growth. In contrast, angiomas in other locations are easily and successfully resected with little blood loss. The location of dural cavernous angiomas is an important factor in making the surgical decision and in predicting the outcome.

Risk of hemorrhage from de novo cerebral aneurysms.

OBJECT A small percentage of patients will develop a completely new or de novo aneurysm after discovery of an initial aneurysm. The natural history of these lesions is unknown. The authors undertook this statistical evaluation a large cohort of patients with both ruptured and unruptured de novo aneurysms with the aim of analyzing risk factors for rupture and estimating a risk of subarachnoid hemorrhage (SAH). METHODS A review of a prospectively maintained database of all aneurysm patients treated by the vascular neurosurgery service of Goodman Campbell Brain and Spine from 1976-2010 was performed. Of the 4718 patients, 611 (13%) had long-term follow-up imaging. The authors identified 27 patients (4.4%) with a total of 32 unruptured de novo aneurysms from routine surveillance imaging. They identified another 10 patients who presented with a new SAH from a de novo aneurysm after treatment of their original aneurysm. The total study group was thus 37 patients with a total of 42 de novo aneurysms. The authors then compared the 27 patients with incidentally discovered aneurysms with the 10 patients with SAH. A statistical analysis was performed, comparing the 2 groups with respect to patient and aneurysm characteristics and risk factors. RESULTS Thirty-seven patients were identified as having true de novo aneurysms. This group had a female predominance and a high percentage of smokers. These 37 patients had a total of 42 de novo aneurysms. Ten of these 42 aneurysms hemorrhaged. De novo aneurysms in both the SAH and non-SAH group were anatomically small (< 10 mm). The estimated risk of hemorrhage over 5 years was 14.5%, higher than the expected SAH risk of small, unruptured aneurysms reported in the ISUIA (International Study of Unruptured Intracranial Aneurysms) trial. There was no statistically significant correlation between hemorrhage and any of the following risk factors: hypertension, diabetes, tobacco and alcohol use, polycystic kidney disease, or previous SAH. There was a statistically significant between-groups difference with respect to patient age, with the mean patient age being significantly older in the SAH aneurysm group than in the non-SAH group (p = 0.047). This is likely reflective of longer follow-up and discovery time, as the mean length of time between initial treatment and discovery of the de novo aneurysm was longer in the SAH group (p = 0.011). CONCLUSIONS While rare, de novo aneurysms may have a risk for SAH that is comparatively higher than the risk associated with similarly sized, small, initially discovered unruptured saccular aneurysms. The authors therefore recommend long-term follow-up for all patients with aneurysms, and they consider a more aggressive treatment strategy for de novo aneurysms than for incidentally discovered initial aneurysms.

Intraoperative Monitoring of the Vagus Nerve during Intracranial Glossopharyngeal and Upper Vagal Rhizotomy

Intracranial section of the glossopharyngeal and upper vagal rootlets for the treatment of vagoglossopharyngeal neuralgia may cause dysphagia or vocal cord paralysis from injury to the motor vagal rootlets in 10% to 20% of cases. To minimize this complication, we recently applied a technique of intraoperative monitoring of the vagus nerve (previously described by Lipton and McCaffery to monitor the recurrent laryngeal nerve during thyroid surgery) in a patient undergoing intracranial rhizotomy for vagoglossopharyngeal neuralgia. By inserting an electrode in the ipsilateral false vocal cord and stimulating the rostral vagal rootlets intraoperatively under general anesthesia, we could differentiate the rostral vagal motor rootlets from the sensory rootlets. In this patient, the technique allowed us to preserve a rostral vagal rootlet, which if sectioned, could have caused dysphagia or vocal cord paralysis. We conclude that intraoperative monitoring of the rostral vagal rootlets is an important technique to minimize complications of upper vagal rhizotomy.