Chiari I malformation: a rare cause of noncommunicating hydrocephalus treated by third ventriculostomy.

OBJECT: Hydrocephalus associated with Chiari I malformation is a rare entity related to an obstruction in the flow of cerebrospinal fluid (CSF) in the foramen of Magendie. Like all forms of noncommunicating hydrocephalus. it can be treated by endoscopic third ventriculostomy (ETV). The object of this study is to report a series of five cases of hydrocephalus associated with Chiari I malformation and to evaluate the use of ETV in the treatment of this anomaly. METHODS: Five patients (four women and one man with a mean age of 29.6 years) underwent ETV for hydrocephalus associated with Chiari I malformation between April 1991 and February 1997. All patients had presented with paroxysmal headaches, which in two cases were associated with visual disorders. All patients had also presented with hydrocephalus (mean transverse diameter of the third ventricle 12.79 mm; mean sagittal diameter of the fourth ventricle 18.27 mm) with a mean herniation of the cerebellar tonsils at 13.75 mm below the basion-opisthion line. Surgery was performed in all patients by using a rigid endoscope. No complications occurred either during or after the procedure, except in one patient who experienced a wound infection that was treated by antibiotic medications. The mean duration of follow up in this study was 50.39 months. Four patients became completely asymptomatic and remained stable throughout the follow-up period. One patient required an additional third ventriculostomy after I year, due to secondary closure, and has remained stable since that time. Postoperative magnetic resonance images demonstrated a significant reduction in the extent of hydrocephalus in all patients (mean transverse diameter of the third ventricle 6.9 mm [p = 0.0035]; mean sagittal diameter of the fourth ventricle 10.32 mm [p = 0.007]), with a mean ascent of the cerebellar tonsils from 13.75 mm below the basion-opisthion line to 7.76 mm below it (p = 0.01). In addition, CSF flow was identified on either side of the orifice of the third ventriculostomy in all patients postoperatively. CONCLUSIONS: Results in this series confirm the efficacy of ETV in the treatment of hydrocephalus associated with Chiari I malformation. It is a reliable, minimally invasive technique that also provides a better understanding of the pathophysiology of this malformation.     

Successful neuroendoscopic third ventriculostomy for hydrocephalus and syringomyelia associated with fourth ventricle outlet obstruction. Case report

The authors report the use of neuroendoscopic third ventriculostomy to treat successfully both hydrocephalus and syringomyelia associated with fourth ventricle outlet obstruction. A 27-year-old woman presented with dizziness, headache, and nausea. Magnetic resonance (MR) imaging demonstrated dilation of all ventricles, downward displacement of the third ventricular floor, obliteration of the retrocerebellar cerebrospinal fluid (CSF) space, funnellike enlargement of the entrance of the central canal in the fourth ventricle, and syringomyelia involving mainly the cervical spinal cord. Cine-MR imaging indicated patency of the aqueduct and an absent CSF flow signal in the area of the cistema magna, which indicated obstruction of the outlets of the fourth ventricle. Although results of radioisotope cisternography indicated failure of CSF absorption, neuroendoscopic third ventriculostomy completely resolved all symptoms as well as the ventricular and spinal cord abnormalities evident on MR images. Neuroendoscopic third ventriculostomy is an important option for treating hydrocephalus in patients with fourth ventricle outlet obstruction.     

Endoscopic third ventriculostomy for treatment of noncommunicating syringomyelia associated with a Chiari I malformation and hydrocephalus: case report and pathophysiological considerations

OBJECTIVE AND IMPORTANCE: A Chiari I malformation associated with syringomyelia and hydrocephalus is a rare condition. We report the successful use of endoscopic third ventriculostomy for the treatment of this pathological entity. The successful use of this technique in such a case has not been previously described, and the results allow us to speculate on the pathophysiological mechanism involved. CLINICAL PRESENTATION: A 34-year-old woman presented with headaches, a motor deficit of the right upper limb, and gait dyspraxia. Magnetic resonance imaging scans demonstrated dilation of all ventricles, compression of the retrocerebellar cerebrospinal fluid space, downward displacement of the tonsils, and syringomyelia. Syringomyelia involved the cervicodorsal cord below C3, with a syrinx-free segment between C1 and C3 and no enlargement of the rostral part of the central canal. INTERVENTION: Endoscopic third ventriculostomy resulted in prompt improvement of the clinical symptoms. Postoperative magnetic resonance imaging scans demonstrated shrinkage of the syrinx and return of the cerebellar tonsils to their physiological positions. CONCLUSION: This experience demonstrates that endoscopic third ventriculostomy, which is a simple, safe technique, may be the treatment of choice for associated Chiari I malformations, hydrocephalus, and syringomyelia (even the noncommunicating type).     

Resolution of trigeminal neuralgia following third ventriculostomy for hydrocephalus associated with Chiari I malformation: case report.

OBJECTIVE AND IMPORTANCE: Cranial nerve dysfunction, including trigeminal neuralgia, has been associated with Chiari I malformations. In such cases, trigeminal neuralgia is thought to be related to tonsillar compression of the brainstem or to traction on the cranial nerves. Hydrocephalus may be a contributing factor. CLINICAL PRESENTATION: A 38-year-old woman had right-sided lancinating facial pain typical of trigeminal neuralgia but was otherwise neurologically intact. Magnetic resonance imaging showed no evidence of a compressing vessel. Moderate hydrocephalus and a Chiari I malformation were noted incidentally. The visibility of the aqueduct was poor. INTERVENTION: The patient underwent a third ventriculostomy and her symptoms resolved completely. CONCLUSION: This is the first case in which trigeminal neuralgia was treated with a third ventriculostomy and one of only four cases of isolated trigeminal neuralgia associated with a Chiari malformation. Acquired aqueductal stenosis may have caused the hydrocephalus which, in turn, caused the Chiari malformation configuration that caused the trigeminal neuralgia. The rationale for the treatment modality and possible causes of Chiari I-induced trigeminal neuralgia are discussed.     

Endoscopic third ventriculostomy for hydrocephalus.

The authors report on 125 patients who underwent endoscopic third ventriculostomy for obstructive hydrocephalus in three Italian Neurosurgical Centers. The series includes 77 cases of primary aqueductal stenosis, 33 with triventricular hydrocephalus due to external tumor compression, and 15 with tetraventricular hydrocephalus. The operations were carried out mainly under general anesthesia, using a flexible endoscope. Decrease of size of the third ventricle and the presence of a signal void at the level of the fenestration are the main postoperative MRI findings. Signs of intracranial hypertension, increased head circumference and Parinaud syndrome respond more frequently to the endoscopic treatment. The overall rate of good results (shunt-independent patients) in this series is 86.4%; primary aqueductal stenosis (93.5%) and triventricular hydrocephalus due to external compression (84.8%) are associated to the higher rate of good postoperative results than tetraventricular hydrocephalus (53.3%). Because of the very low invasivity of this technique, the absence of postoperative mortality and the scarce and usually transient postoperative complications, the authors advise to enlarge the indications for endoscopic third ventriculostomy to all patients with obstructive hydrocephalus when the third ventricle is large enough and there are no alterations of the CSF resorption.     

Initial management of hydrocephalus associated with Chiari malformation Type I-syringomyelia complex via endoscopic third ventriculostomy: an outcome analysis

OBJECT: The aim of this study was to evaluate the efficacy of endoscopic third ventriculostomy (ETV) in patients with Chiari malformation Type I (CM-I) and hydrocephalus with or without syringomyelia. METHODS: The authors identified, in a prospective endoscopy database, 16 adults and children (age range 2-68 years) with CM-I and hydrocephalus that had been managed with ETV. They reviewed the clinical features and radiographic findings for all patients. Fifteen patients underwent ETV as a primary treatment, whereas 1 patient underwent the procedure at the time of shunt failure. All patients had symptomatic hydrocephalus with either aqueductal or fourth ventricular outflow obstruction. The mean duration of follow-up was 42 months. RESULTS: Fifteen patients (94%) remain shunt free following ETV for CM-I. Five (83%) of the 6 patients with a syrinx had improvement or resolution of the syrinx following ETV. Six patients (37.5%) underwent foramen magnum decompression for persistent CM-I -- or syrinx-related symptoms. There was no cerebrospinal fluid leakage or intracranial pressure-related problem following foramen magnum decompression. CONCLUSIONS: Endoscopic third ventriculostomy provides a durable method of treatment for hydrocephalus associated with CM-I. It is effective as a primary treatment, and the authors advocate its use as a replacement for routine ventriculoperitoneal shunt insertion in these patients. Management of the hydrocephalus alone is often sufficient and may obviate decompression, although a significant proportion of patients will still need both procedures.     

Unsuccessful third ventriculostomy for occlusive hydrocephalus.

For non-communicating hydrocephalus, neuroendoscopic third ventriculostomy has become a major choice. But sometimes, the procedure results in failure. Typically, impairment of a distal CSF absorption, a preexisting arachnoid membrane just below the fenestrated site and a glial scarring of fenestrated site were pointed out as a factors of failure. On the other side, the intraventricular pressure dynamics of a functioning third ventriculostomy is in the process of study. Recently some reports have noticed the importance of the flow of CSF into the prepontine cistern, mimicking the flow through the aqueduct of Sylvius. We report an unsuccessful trial of third ventriculostomy in a case with huge posterior fossa tumor.     

第三脑室底造瘘治疗脑积水的手术并发症

目的 探讨第三脑室底造瘘治疗脑积水产生手术并发症的原因及预防措施。方法 对13例（15例次）行第三脑室底造瘘术治疗脑积水出现并发症的情况进行回顾性分析。结果 本组患者出现脑室内感染2例、膜膜下积液1例、造瘘口再堵塞1例、术中出血后的血凝块堵塞第三脑室形成脑疝1例。并发症的主要原因为手术设备的不良和先期经验的不足。结论 采用良好的手术设备,提高对各种并发症发生原因的不足,可减少手术并发症的发生。     

Spontaneous resolution of syringomyelia without Chiari malformation

A 30-year-old woman presented with a cervical syrinx manifesting as hemihypesthesia. Neuroimaging found no evidence of Chiari malformation or tight cisterna magna. Serial magnetic resonance imaging studies over a 6-year period demonstrated spontaneous and complete resolution of the syrinx accompanied by an asymptomatic clinical course. The natural history of syringomyelia is highly unpredictable. The outcome of surgical treatment for patients with syringomyelia is not always satisfactory, so the indications for surgery are controversial. Spontaneous resolution of syringomyelia unrelated with foramen magnum lesion has various causes. Close follow up of the patient is necessary to monitor for recurrence.     

Endoscopic third ventriculostomy for obstructive hydrocephalus

The indications for neuroendoscopy are not only constantly increasing, but even the currently accepted indications are constantly being adjusted and tailored. This is also true for one of the most frequently used neuroendoscopic procedures, the endoscopic 3rd ventriculostomy (ETV) for obstructive hydrocephalus. ETV has gained popularity and widespread acceptance during the past few years, but little attention has been paid to the techniques of the procedure. After a short introduction describing the history of ETV, an overview is given of all the different techniques that have been and still are employed to open the floor of the 3rd ventricle. The spectrum of indications for ETV has been widely enlarged over the last years. Initially, the use of this procedure was restricted to patients older than 2 years, to patients with an obvious triventricular hydrocephalus, and to those with a bulging, translucent floor of the 3rd ventricle. Nowadays, indications include all kinds of obstructive hydrocephalus but also communicating forms of hydrocephalus. The results of endoscopic procedures in treating these pathologies are given under special consideration of shunt technologies. In summary, from the review of the publications since the first ETV performed by Mixter in 1923, this technique is the treatment of choice for obstructive hydrocephalus caused by different etiologies and is an alternative to cerebrospinal fluid shunt application.Commentaries on this paper are available at and     

Long-term outcome of endoscopic third ventriculostomy in obstructive hydrocephalus.

This multicentric study reports on 140 patients who underwent endoscopic third ventriculostomy for obstructive hydrocephalus in four Italian neurosurgical centers between 1994 and 1999. Its aim is to define the long-term outcome of these patients many years (6-12) after the initial procedure. The study includes both children and adults; the etiology of the hydrocephalus was malformative aqueductal stenosis in 88 cases (62.8%), compression by tumors of the mesencephalic and pineal regions and posterior fossa in 45 (32.2%) and post-infection aqueductal stenosis in 7 (5%). The ETV was performed by using the standard technique. The overall rate of good results (shunt-independent patients with clinical remission or improvement) was 87.1%. Eighteen patients (12.9%) required a shunt because of ETV failure. The long-term outcome of ETV in this study was not influenced by the patient's age and the etiology of the hydrocephalus (although cases secondary to cisternal hemorrhage and infections are not included). Other series including cases with long follow-up are analyzed. In conclusion, ETV results in a high rate of good long-term outcome in patients with obstructive hydrocephalus. Because postoperative failures occur early, clinical and radiological control studies must be performed particularly in the first years after the neuroendoscopic procedure.     

Chiari I malformation with syringomyelia. Evaluation of surgical therapy by magnetic resonance imaging

Five patients with a Chiari I-syringomyelia complex of adult onset were evaluated by magnetic resonance (MR) imaging. All patients underwent suboccipital craniotomy with upper cervical (C-1 and part of C-2) laminectomy, arachnoid retraction, and duraplasty. Postoperative MR studies of four patients disclosed collapse of the syringomyelic cavity, even when the cavity extended into the thoracic region. This appeared to be a progressive process taking place over several weeks. Operative complications are noted and physiological implications are discussed.