Cyst Shunting Research Articles

Effectiveness of multiple endoscopic fenestrations for the treatment of Sylvian fissure arachnoid cysts: a multicenter study.

Arachnoid cysts are usually asymptomatic lesions. However, they can sometimes cause intracranial hypertension, headache, seizures, focal neurological deficits, and bleeding. The most commonly used surgical techniques are microsurgical cyst fenestration/excision/drainage, cyst shunting, and endoscopic procedures. We aimed to investigate the success of different surgical techniques. Between 2000 and 2021, patients with Sylvan fissure arachnoid cysts who received treatment via an endoscopic approach chosen as the first-line treatment in three centers were enrolled. All case notes and radiological studies were evaluated retrospectively. The study included 131 (female, n = 28; male, n = 103) patients with a mean age of 87.04 ± 66.76 (range, 0-216) months. Of the patients, 25 had Galassi type II left-sided arachnoid cysts, 33 had Galassi type II right-sided arachnoid cysts, 40 had Galassi type III left-sided arachnoid cysts, and 32 had Galassi type III right-sided arachnoid cysts. No difference was found between patients who underwent single and multiple fenestrations in terms of Galassi type, side, clinical outcome, and cyst size (p > 0.05). On the contrary, the rate of additional surgical intervention was lower in patients with multiple fenestrations than in those with single fenestration (36.10% vs. 5.30%; p < 0.001). Endoscopic fenestration of Sylvian fissure arachnoid cysts is a good alternative to open surgery or cystoperitoneal shunting, and the number of fenestrations made during this surgery decreases the need for a second surgical procedure.

An unusual case of dysphagia

A 51-year-old lady, with a background of an arachnoid cyst and ventriculo-peritoneal shunt in situ, presented to the Acute Medical Unit with a 2-day history of neck pain. She awoke from sleep with the pain and it persisted since. She had not been involved in any trauma, had no previous history of neck or back pain and her pain was not controlled with simple analgesia. She also complained of new odynophagia and high dysphagia, particularly to solid foods. There was no history of upper respiratory tract infection.

Spinal cord injury below-level neuropathic pain relief with dorsal root entry zone microcoagulation performed caudal to level of complete spinal cord transection.

OBJECTIVE Surgically created lesions of the spinal cord dorsal root entry zone (DREZ) to relieve central pain after spinal cord injury (SCI) have historically been performed at and cephalad to, but not below, the level of SCI. This study was initiated to investigate the validity of 3 proposed concepts regarding the DREZ in SCI central pain: 1) The spinal cord DREZ caudal to the level of SCI can be a primary generator of SCI below-level central pain. 2) Neuronal transmission from a DREZ that generates SCI below-level central pain to brain pain centers can be primarily through sympathetic nervous system (SNS) pathways. 3) Perceived SCI below-level central pain follows a unique somatotopic map of DREZ pain-generators. METHODS Three unique patients with both intractable SCI below-level central pain and complete spinal cord transection at the level of SCI were identified. All 3 patients had previously undergone surgical intervention to their spinal cords-only cephalad to the level of spinal cord transection-with either DREZ microcoagulation or cyst shunting, in failed attempts to relieve their SCI below-level central pain. Subsequent to these surgeries, DREZ lesioning of the spinal cord solely caudal to the level of complete spinal cord transection was performed using electrical intramedullary guidance. The follow-up period ranged from 1 1/2 to 11 years. RESULTS All 3 patients in this study had complete or near-complete relief of all below-level neuropathic pain. The analyzed electrical data confirmed and enhanced a previously proposed somatotopic map of SCI below-level DREZ pain generators. CONCLUSIONS The results of this study support the following hypotheses. 1) The spinal cord DREZ caudal to the level of SCI can be a primary generator of SCI below-level central pain. 2) Neuronal transmission from a DREZ that generates SCI below-level central pain to brain pain centers can be primarily through SNS pathways. 3) Perceived SCI below-level central pain follows a unique somatotopic map of DREZ pain generators.

Treatment of syringomyelia associated with adhesive arachnoiditis

To define the optimal amount of surgery for SM associated with AA and the criteria for assessment of surgery outcomes. The authors treated 47 SM patients in the period from 2010 to 2015. Of these, 34 (72.3%) patients underwent surgery; a total of 40 operations were performed. The patients' age ranged from 18 to 64 years (mean, 43.5 years). Tethering of the spinal cord was eliminated in 25 patients; 9 patients underwent cyst shunting. Among operated patients, 5 patients had grade 1 arachnopathy, 13 patients had grade 2 arachnopathy, 12 patients had grade 3 arachnopathy, and 4 patients had grade 4 arachnopathy. The minimal postoperative follow-up period was 11 months. After shunting, the condition improved in 8 of 9 patients; in 7 patients, the condition returned to the baseline level within the first postoperative year; in 6 (66.7%) of these patients, the disease continued to progress. After surgical release of spinal cord tethering, satisfactory long-term results were achieved in 13 (86.6%) patients with grade 1-2 arachnopathy. In 3 (50%) patients with grade 3 arachnopathy, the condition was stabilized. Among patients with grade 4 arachnopathy, progression of the disease was stopped in 1 patient; the condition worsened in 2 (50%) patients. Among all the operated patients, complications developed in 7 patients. There were no lethal outcomes. In grade 1-2 arachnopathy, progression of SM after release of spinal cord tethering occurs only in 13.4% of patients. Therefore, release of spinal cord tethering is recommended for these patients. In grade 3-4 arachnopathy, the rate of relapse after this surgery is more than 80%. Therefore, given the simplicity and a lower risk of complications of cyst shunting, this procedure is advisable for these patients.

Microsurgical fenestration and cystoperitoneal shunt through preauricular subtemporal keyhole craniotomy for the treatment of symptomatic middle fossa arachnoid cysts in children.

The optimal surgical treatment for symptomatic middle fossa arachnoid cyst is still controversial. The most leading therapeutic options include cyst shunting and fenestration (endoscopic, microsurgical). We present our experience on surgical treatments of arachnoid cysts. A retrospective data review of 16 children who underwent keyhole craniotomy for microsurgical fenestration and shunting of middle fossa arachnoid cysts between 1999 and 2012 was performed after institutional review board approval. The average patient age was 6.1 years. The average follow-up period was 36.5 months. There were ten male and six female patients in the series. Indications for surgery included intractable headaches (50%), increasing in cyst size (18.75%), and seizures (31.25%). All patient records were reviewed for their clinical presentation, classification, cyst resolution, symptom resolution, and cyst outcomes. After surgery, all patients underwent assessments of clinical and radiological improvement. Postoperative complications were observed in two cases: progressively resolving monoparesia in one case and resolving epileptic seizure with monotherapy in the other. All patients had a satisfactory clinical outcome, and in 87.5%, there was either a decrease in the size or a complete disappearance of the MFAC. Nevertheless, three (18.75%) of all patients needed shunt revision because of shunt dysfunction. Complication related to surgical technique was cerebrospinal fluid leak which spontaneously resolved in one patient. Microsurgical fenestration with keyhole craniotomy to provide passage between cysts to basal cisterns together with cystoperitoneal shunting during the same operation is still an effective and safe method in cases with symptomatic middle fossa arachnoid cysts in children.

Surgical tactics and results of posttraumatic syringomyelia treatment

Introduction. The purpose of the research was to study features of posttraumatic cysts flow and rational tactics for their treatment was developed.Materials and methods. The research is based on results of 280 patients treatment. Surgical intervention was performed in 78 cases, in 69 — middle myelotomy with cysts opening, in 8 — different variants of subarachnoid shunt and in one — cyst-peritoneal shunt was applied.Results. In 54 cases directly after surgery regression of neurological symptoms was observed. In these patients the period from post-traumatic cyst emergence to surgery performing did not exceed 3 years.Conclusions. Simple cyst opening is possible only at adequate recovery of liquor circulation in the area of spinal cord injury. If you failed to restore liquor circulation, shunting of cysts is needed.

Surgical decompression of arachnoid cysts: a study on 44 pediatric patients

Abstract Background: There are yet to clarify some aspects regarding the surgical indications and surgical methods that are at choice for treating ACs. The purpose of the study is to contribute to the ongoing debate on the most appropriate treatment. Materials and methods: We included in the study 44 pediatric patients (aged &lt; 18 years), operated for ACs in the Neurosurgery I Department, of the Emergency Clinical Hospital “Bagdasar- Arseni” in Bucharest, during the period January 2003 to December 2012. The surgical methods were either a craniotomy or cyst shunting. The information regarding these patients was retrospectively assessed based on their clinical and imaging records, and cross checked with the OR protocols. Treatment efficiency was evaluated considering postoperative clinical status, imaging appearance and postoperative complications. Results: 84.1% of the patients reported postoperative disappearance or reduction of symptoms, while 13.6 had the same complaints as prior surgery. Only one patient experienced worsening of symptoms. Follow-up imaging showed cyst disappearance in 29.5% patients and cyst reduction in 61.4% patients. 9.1% had no change in cyst volume. Craniotomy correlated with a better imaging appearance (p=0.02). There was no correlation between improved clinical status and cyst fluid reduction (p=0.6). 9 patients (20.4%), all with temporal cysts, experienced postoperative complications, and 7 of them (15, 9%) needed surgery. There was no severe or permanent dysfunction in any of the patients. 42.8% of the cyst shunting patients suffered postoperative complications, whereas only 10% of the craniotomy patients did. Conclusion: Cyst decompression results in significant clinical improvement and it can be performed with little risk for severe complications. Craniotomy seems to be a better surgical treatment option than cystoperitoneal shunt, with a better neuroimaging appearance and a lower complications rate

Shunt dependency syndrome after cystoperitoneal shunting of arachnoid cysts

The goal of this study was to investigate the mechanisms, diagnosis, and treatment of shunt dependency syndrome in patients with temporal lobe arachnoid cysts who were initially treated with cystoperitoneal (CP) shunting. Thirteen patients with temporal lobe arachnoid cysts who had initially been treated with CP shunt placement and had developed shunt dependency syndrome were treated by the senior author at Tiantan Hospital between April 2010 and January 2012. The clinical manifestations, neuroimaging findings, intracranial pressure (ICP) data, treatment methods, and therapeutic results were reviewed retrospectively. The study included ten males and three females. The mean age at the time of development of shunt dependency syndrome was 12.3 years (range 5.5-24 years). In most patients, neuroimaging findings showed a collapsed cyst (the cyst appeared almost unchanged in only one patient) and normal or small ventricles (only one patient had enlarged ventricles). Three patients underwent simple replacement of the shunt, four underwent ventriculoperitoneal shunt placement, and the other six underwent lumboperitoneal shunt placement. All patients experienced resolution of their symptoms postoperatively. The mean duration of follow-up was 20 months. Shunt dependency syndrome is a rare but serious complication of shunting an arachnoid cyst. This condition is similar to the slit ventricle syndrome, but also has some differences. ICP monitoring may confirm the diagnosis when there are no significant radiological findings. Achievement of a shunt-free state might be the ultimate goal for all shunted patients.

Endoscopy versus microsurgical cyst excision and shunting for treating intracranial arachnoid cysts

Endoscopic surgery is routinely used to treat intracranial arachnoid cysts. However, the indications and results with respect to the different cyst locations, compared with those of microsurgical fenestration and cyst shunting, deserve to be discussed. The authors review 18 patients with intracranial arachnoid cysts treated by pure endoscopic technique in their neurosurgical department. There were 10 male and 8 female patients ranging in age from 2 months to 48 years (median age 19.4 years). The cyst location was suprasellar in 5 cases, quadrigeminal in 5, cortical hemispheric in 2, sylvian region in 3, and posterior fossa in 3. The authors also reviewed the literature, comprising 61 reports for an overall number of 645 patients with intracranial arachnoid cysts treated by different surgical techniques. These techniques included microsurgical excision or fenestration by craniotomy, cyst shunting, and endoscopic fenestration. The surgical results of the different techniques according to the different cyst locations underwent statistical analysis. The overall success rate (complete or partial clinical remission) in the authors' endoscopic series was 83.3% (15 of 18 cases), which is rather similar to that of 222 patients treated endoscopically and reported on in the literature (84.2%). In the overall endoscopic group, a higher success rate was found for cysts in the suprasellar (89.7%), quadrigeminal (88.5%), and posterior cranial fossa (83.3%) regions compared with sylvian (70%) and cortical and interhemispheric (75%) regions. The statistical comparison of the results of the endoscopic series with those of craniotomy and shunting revealed no significant differences for suprasellar, quadrigeminal, or posterior cranial fossa cysts, whereas the success rate of endoscopy is lower than that of other techniques for sylvian and cortical cysts. Endoscopy is a safe and effective therapeutic modality for patients with intracranial arachnoid cysts. Cysts of the suprasellar and quadrigeminal regions and posterior fossa are the best indications for neuroendoscopy; on the other hand, cortical cysts are best treated by microsurgical fenestration or shunting. For sylvian cysts, the endoscopic procedure may be advocated in most cases.

Reply to the comment to the paper (CNS-09-0420) “The clinical spectrum of Blake’s pouch cyst: report of 6 illustrative cases” by Professor Charles Raybaud

Reply to the comment to the paper (CNS-09-0420) “The clinical spectrum of Blake’s pouch cyst: report of 6 illustrative cases” by Professor Charles Raybaud

Posttraumatic spinal cord tethering and syringomyelia: surgical treatment and long-term outcome

Permanent neurological loss after spinal cord injury (SCI) is a well-known phenomenon. There has also been a growing recognition and improved understanding of the pathophysiological mechanisms of late progressive neurological loss, which may occur after SCI as a result of posttraumatic spinal cord tethering (SCT), myelomalacia, and syringomyelia. A clinical study of 404 patients sustaining traumatic SCIs and undergoing surgery to arrest a progressive myelopathy caused by SCT, with or without progressive myelomalacia and cystic cavitation (syringomyelia) was undertaken. Both objective and subjective long-term outcomes were evaluated. To the authors' knowledge, this is the first series of this size correlating long-term patient perception of outcome with long-term objective outcome analyses. During the period from January 1993 to November 2003, 404 patients who had previously sustained traumatic SCIs underwent 468 surgeries for progressive myelopathies attributed to tethering of the spinal cord to the surrounding spinal canal, with or without myelomalacia and syrinx formation. Forty-two patients were excluded because of additional pathological entities that were known to contribute to a progressive myelopathy. All surgeries were performed by the same neurosurgeon at a single SCI treatment center and by using a consistent surgical technique of spinal cord detethering, expansion duraplasty, and when indicated, cyst shunting. Outcome data were collected up to 12 years postoperatively. Comparisons of pre- and postoperative American Spinal Injury Association sensory and motor index scores showed no significant change when only a single surgery was required (86% of patients). An outcome questionnaire and phone interview resulted in > 90% of patients self-assessing arrest of functional loss; > 50% of patients self-assessing improvement of function; 17 and 18% self-assessing improvement of motor and sensory functions to a point greater than that achieved at any time postinjury, respectively; 59% reporting improvement of spasticity; and 77% reporting improvement of hyperhidrosis. Surgery for spinal cord detethering, expansion duraplasty, and when indicated, cyst shunting, is a successful treatment strategy for arresting a progressive myelopathy related to posttraumatic SCT and syringomyelia. Results suggest that surgery leads to functional return in ~ 50% of patients, and that in some patients posttraumatic SCT limits maximal recovery of spinal cord function postinjury. A patient's perception of surgery's failure to arrest the progressive myelopathy corresponds closely with the need for repeat surgery because of retethering, cyst reexpansion, and pseudomeningocele formation.

Symptomatic prepontine cistern flattening after an arachnoid cyst shunting:: a report of 2 cases

Background Controversy still exists about the best management modality for congenital arachnoid cyst. Shunting procedures have been one of the treatment options offered to patients with this condition. Although arachnoid cysts shunting have been associated with a variety of clinical conditions, its relationship with flattened prepontine cistern has not been described. Case Description We describe two children with congenital arachnoid cyst managed with cystoperitoneal shunt, both of whom were later discovered to have developed flattened prepontine cistern and imaging findings of overcrowding of the posterior cranial fossa. Conclusion These cases demonstrate that flattening of the prepontine cisterns and acquired posterior cranial fossa overcrowding may be a potential fall out in patients with cystoperitoneal shunt due to an arachnoid cyst.

Endoscopic treatment of middle fossa arachnoid cysts: a series of 40 patients treated endoscopically in two centres

Middle fossa arachnoid cysts (MFAC) are a relatively common, benign pathology that pose a therapeutic challenge for both symptomatic and asymptomatic patients. The optimal surgical strategy and indication to treat are still debated by neurosurgeons. We reviewed our experience and results in a group of patients treated with endoscopic fenestration with the aim to assess indications to treat and clinical and neuroradiological results. The data on 40 patients operated with endoscopic fenestration for MFAC in two centres, "Anna Meyer" Children's Hospital, Florence, Italy, and Royal Liverpool Children's Hospital "Alder Hey", Liverpool, UK, between 2001 and 2007 were retrospectively reviewed with prospective follow-up. We analysed clinical and neuroradiological presentation, indications to treat, surgical technique, complications, and clinical and neuroradiological follow-up. There were 30 males and ten females: mean age, 7.8 years; mean follow-up, 21 months. The neuronavigation system was used in 12 patients in the English cohort. Thirty-seven patients (92.5%) had a satisfactory clinical outcome. The cyst was reduced in size or completely disappeared in 29 patients (72.5%). There was no death or significant morbidity associated with the procedure. Four patients required further surgical treatment. Four patients experienced a post-traumatic intracystic bleeding after surgery. Compared to microsurgical fenestration and cyst shunting, our experience with endoscopic fenestration was as effective and safe but less invasive. Each case must be assessed with its individual characteristics to define the optimal surgical strategy. Successful treatment may not reduce the risk of post-traumatic head injury haemorrhage.

Sylvian fissure arachnoid cysts: a survey on their diagnostic workout and practical management

The management of Sylvian arachnoid cysts in children is still a matter of debate. Diagnosis is often incidental, and symptoms are frequently aspecific in symptomatic cases. Suggested diagnostic investigation results have been often unclear. Surgical treatment is also controversial, pure, and assisted endoscopic cyst marsupialization having entered in the traditional debate between craniotomic and shunting approach The objective of the present study was to survey if (and, eventually, which) agreement points do actually exist between internationally recognized pediatric neurosurgery centers in the management of children with a controversial type of Sylvian arachnoid cyst (Type II cyst). Contributors were asked to answer to a six-separate-part multiple choice questionnaire related to the case of a 2.7-year-old boy with a Type II left Sylvian arachnoid cyst presented in different clinical situations. If surgery was indicated, it was asked which surgical procedure the authors would have suggested as first option. The option of the mere clinical observation was chosen by the majority of surgeons in case of asymptomatic clinical discovery. On the other hand, a constantly high percentage of participants suggested direct surgical treatment based on clinical manifestations or as a preventive measure justified by the risk of spontaneous or traumatic intracranial bleeding. The only diagnostic investigation result which significantly influenced the surgical indication was a localizing electroencephalography, if the child presented with seizures. The result is that in most cases the surgical indication was based on aspecific clinical manifestations and laboratory data. Craniotomy and arachnoid cyst marsupialization represented the preferred surgical option (66.6%), 28.8% of the participants suggesting pure or assisted endoscopic cyst marsupialization as primary surgical procedure. Cyst shunting was suggested by only three centers.

Herniation of the cerebellar tonsils after suprasellar arachnoid cyst shunt: case report

It is known that the caudal dislocation of the cerebellar tonsils may occur associated with clinical conditions such as an intracranial mass lesion or Chiari I and II malformation. It may also be acquired after repeated lumbar punctures or lumboperitoneostomy. The occurrence of cerebellar herniation after derivation of intracranial arachnoid cyst is extremely rare, and there are only three cases reported in the medical literature. We present the case of a 9-year-old boy with precocious puberty and suprasellar arachnoid cyst who developed a symptomatic herniation of the cerebellar tonsils three years after a cystoperitoneostomy. The patient underwent a suboccipital craniectomy with duraplasty and partial tonsillectomy, showing afterwards, remission of the symptoms. We discussed the pathogenesis suggested in the literature.

Cystoventricular Shunting of Intracranial Arachnoid Cysts

Ten patients with intracranial arachnoid cysts were treated with direct shunting of the cyst to a lateral ventricle. The strategic goal of cystoventricular shunting is to establish physiologically normal intracranial pressure relationships, rather than cyst obliteration. Cystoventricular shunts were successful in treating single and multiple intracranial cysts in supratentorial and infratentorial locations and in patients with normal and enlarged lateral ventricles. Cystoventricular shunting is conceptually simple as well as effective and reliable.

Microsurgical keyhole approach for middle fossa arachnoid cyst fenestration.

The optimal surgical treatment for symptomatic temporal arachnoid cysts is controversial. Therapeutic options include cyst shunting, endoscopic fenestration, and craniotomy for fenestration. We reviewed the results for patients who were treated primarily with craniotomy and fenestration at our institution, to provide a baseline for comparisons of the efficacies of other treatment modalities. A retrospective review of data for 50 children who underwent keyhole craniotomy for fenestration of temporal arachnoid cysts between 1994 and 2001 was performed after institutional review board approval. During that period, the first-line treatment for all symptomatic middle fossa arachnoid cysts was microcraniotomy for fenestration. Microsurgical dissection to create communications between the cyst cavity and basal cisterns was the goal. All patient records were reviewed and numerous variables related to presentation, cyst size and classification, treatment, cyst resolution, symptom resolution, follow-up periods, and cyst outcomes were recorded. Fifty temporal arachnoid cysts in 50 treated patients were identified. The average age at the time of surgery was 68 +/- 57.2 months. The follow-up periods averaged 36 months. There were 34 male and 16 female patients in the series. Twenty-six cysts were on the left side. Indications for surgery included intractable headaches (45%), increasing cyst size (21%), seizures (25%), and hemiparesis (8%). The symptoms most likely to improve were hemiparesis (100%) and abducens nerve palsies. Headaches (67%) and seizure disorders (50%) were less likely to improve. Nine patients exhibited progressive increases in cyst size in serial imaging studies. Those patients were monitored for a mean of 40 +/- 23 months before intervention. In the entire series, 82% of patients demonstrated decreases in cyst size in serial imaging studies. Of those patients, 18% demonstrated complete cyst effacement. Overall, 83% of patients with Grade II cysts and 75% of patients with Grade III cysts exhibited evidence of decreases in cyst size in long-term monitoring. Two patients required shunting after craniotomy (4%). Hospital stays averaged 3.4 days. Total surgical times averaged 115 minutes. No significant blood loss occurred (5-50 ml). Complications included spontaneously resolving pseudomeningocele (10%), transient Cranial Nerve III palsy (6%), cerebrospinal fluid leak (6%), subdural hematoma (4%), and wound infection (2%). A microsurgical keyhole approach to arachnoid cyst fenestration is a safe effective method for treating middle fossa cysts. This procedure can be performed with minimal morbidity via a minicraniotomy. Compared with an endoscopic approach, better control of hemostasis can be obtained, because of the ability to use bipolar forceps and other standard instruments. The operative time and length of hospital stay were not excessively increased.

Ultrasonographic differential diagnosis of fetal intracranial interhemispheric cysts

Objective: Ultrasonographic differentiation between intracranial supratentorial interhemispheric pathologic cystlike lesions and those related to physiologic median structures is essential because the latter have no clinical relevance, whereas the former may carry a poor prognosis. We reviewed our experience with 19 consecutive cases of interhemispheric hypoechoic lesions without parenchymal involvement diagnosed between January 1990 and June 1997 to establish their clinical significance and provide prenatal ultrasonographic criteria to distinguish between pathologic cystlike lesions and those related to physiologic midline structures. Study Design: All patients underwent targeted prenatal scans of intracranial anatomy to establish the relationship between the fluid collections and the surrounding parenchymal and ventricular structures. In addition, a detailed anatomic survey was performed to rule out associated malformations. Follow-up, including neurologic examination, imaging, autopsy evaluation, or a combination was performed in all cases. Statistical analysis used the Wilcoxon rank sum test, the Fisher exact test, and the χ 2 test for trend. P < .05 was considered significant. Results: Cystlike lesions related to physiologic median structures (n = 12) included enlargement of the cavum septi pellucidi (n = 3), enlargement of the cavum vergae (n = 2), and cysts of the velum interpositum (n = 7). These lesions were unilocular and had a median size of 10 mm (range 10-30 mm); they resolved in 5 cases and remained stable in the remainder. They were not associated with overt abnormalities, other than borderline ventriculomegaly in 2 cases. Pediatric follow-up (median 26 months, range 3-84 months) showed normal neurodevelopment in all cases. Pathologic cystlike lesions (n = 7) were significantly larger (median 40 mm, range 10-80 mm, P = .004) and had a significantly worsening trend, growing more at serial prenatal ultrasonographic examinations ( P = .039) than fluid collections related to physiologic median structures. Moreover, prenatal ultrasonographic evidence of associated intracranial abnormalities, in the form of partial or total agenesis of the corpus callosum and overt hydrocephalus, was present in 5 of 7 cases of pathologic cystlike lesions and in none of the 12 related to physiologic structures ( P = .002). Median gestational age at diagnosis was not different between those with cystlike lesions related to physiologic median structures and those with pathologic lesions (30 and 31 weeks, respectively). Among the latter group, 1 pregnancy was voluntarily terminated, 1 infant died at 4 months of age, 2 infants had neurodevelopmental delay, and 3 infants were neurologically healthy at a mean follow-up of 43 months. Cyst shunting was necessary in 5 of 6 cases. Conclusions: Interhemispheric cystlike lesions related to physiologic structures can be prenatally distinguished from pathologic fluid collections on the basis of location, cyst size, change in size with time, and absence of associated anomalies.(Am J Obstet Gynecol 1999;180:423-8.)

Surgical Treatment of Posttraumatic Cystic and Tethered Spinal Cords

Posttraumatic syringomyelia as a cause of progressive neurologic deterioration has been well described. More recently, the noncystic posttraumatic tethered cord has been associated with identical progressive neurologic deterioration.A retrospective analysis of patients treated surgically with spinal cord untethering and/or cyst shunting to arrest a progressive myelopathy from a posttraumatic tethered and/or cystic cord was performed. Emphasis was on outcome using the American Spinal Injury Association (ASIA) sensory and motor scoring systems.During an 18-month period from May 1993 to December 1994, 70 patients with spinal cord injury were operated upon for tethered and/or cystic spinal cords because of a progressive myelopathy and deteriorating ASIA sensory/motor scores. Fifty-nine patients had follow-up data 1 year postoperatively. At the 1 year follow-up, there was small improvement in light touch sensory scores (0.67 points), pinprick scores (1.3 points), and motor scores (0.41 points) demonstrating that the progression of the myelopathic process was arrested. Thirty-four of these 59 patients had no previous surgery to their spinal cords. At 1 year follow-up, light touch scores improved on average 2.38 points, pinprick scores 3.88 points (p < 0.05), and motor scores 1.47 points, suggesting better outcome with first-time surgery. Of this latter group, 64.3% regained a lost function, 62.5% saw improvement in spasticity, 55.6% had substantial improvement in neurogenic pain, and 95.8% felt that surgery prevented further neurologic deterioration.

Utility of Frameless Stereotaxy in the Resection of Skull Base and Basal Cerebral Lesions in Children

Since 1991, we have performed nearly 300 stereotactic procedures using the ISG viewing wand on a variety of cranial lesions in patients under 22 years of age. Of these, 38 procedures were performed on 34 patients for basal cerebral and skull base lesions. Our patients ranged in age from 3.5 months to 22 years with a mean age of 9.45 years. There were 18 females and 16 males. Twenty-one patients had basal cerebral lesions located in the thalamus (10), basal ganglia (2), third ventricle (2), and hypothalamus (7). Thirteen patients had skull base lesions located within the anterior optic apparatus (3), sella turcica (4), middle and posterior cranial fossae (4), and craniocervical region (2). Preoperative CT and/or MRI scan images were taken as a volume acquisition and transferred to the computer workstation utilizing the ISG Wand software. This workstation was transferred to the operating room where it was calibrated to a faro Surgicom arm which interfaces with the patient and the three-dimensional radiological image. The ISG Wand was utilized to plan the scalp and bone flaps and to select the optional trajectory to lesion. The surgical approaches which were specifically used in this series with the ISG Wand included transcallosal (15), pterional (5), frontal (3), subtemporal (4), transsphenoidal (3), temporal (3), tumor cyst shunt insertion (1), burr hole drainage (1), transoral (2), bifrontal (1), bifrontal mid facial (1), and transnasal (1). Although brain shift occurred following craniotomy and with brain retraction, the relative immobility of these lesions at the skull or cerebral base permitted an accurate targeting of all lesions with an error range of 1.0-2.5 mm throughout the entire procedure. This relatively precise intraoperative feedback led to more accurate recognition of tumor landmarks. It is the authors' impression that a more aggressive resection of these lesions was achieved than could be without the device. We conclude that a frameless stereotactic device such as the ISG Wand is particularly valuable in the approach to skull base and basal cerebral tumors in children.