Gamma knife radiosurgery cured hydrocephalus in non-hemorrhagic brain stem arteriovenous malformation

Unveiling the domino effect: a nine-year follow-up on pentalogy of central nervous system induced by a large unruptured cerebral arteriovenous malformation: a case report and literature review

Background

The disruption of intracranial fluid dynamics due to large unruptured cerebral arteriovenous malformation (AVM) commonly triggers a domino effect within the central nervous system. This phenomenon is frequently overlooked in prior clinic and may lead to catastrophic misdiagnoses. Our team has documented the world's first case of so-called AVM Pentalogy (AVMP) induced by a AVM.

Clinical presentation and result

A 30-year-old female was first seen 9 years ago with an occasional fainting, at which time a huge unruptured AVM was discovered. Subsequently, due to progressive symptoms, she sought consultations from several prestigious neurosurgical departments in China, where all consulting neurosurgeons opted for conservation treatment due to perceived surgical risks. During the follow-up period, the patient gradually presented with hydrocephalus, empty sella, secondary Chiari malformation, syringomyelia, and scoliosis (we called as AVMP). When treated in our department, she already displayed numerous symptoms, including severe intracranial hypertension. Our team deduced that the hydrocephalus was the primary driver of her AVMP symptoms, representing the most favorable risk profile for intervention. As expected, a ventriculoperitoneal shunt successfully mitigated all symptoms of AVMP at 21-months post-surgical review.

Conclusion

During the monitoring of unruptured AVM, it is crucial to remain vigilant for the development or progression of AVMP. When any component of AVMP is identified, thorough etiological studies and analysis of cascade reactions are imperative to avert misdiagnosis. When direct AVM intervention is not viable, strategically addressing hydrocephalus as part of the AVMP may serve as the critical therapeutic focus.

Upfront Radiosurgery for Treatment of Symptomatic Obstructive Hydrocephalus due to Brain Tumors

Introduction

Hydrocephalus is a build-up of cerebrospinal fluid (CSF) in the brain and is characterized by abnormal dilatation of the cerebral ventricles. Patients can be either asymptomatic, have symptoms related to primary tumors, or have hydrocephalus-related symptoms. Generally, symptomatic patients are candidates for ventriculoperitoneal (VP) shunt placement to reduce acute symptoms. Little evidence exists regarding the resolution of symptomatic hydrocephalus secondary to brain tumors using stereotactic radiosurgery (SRS) alone as a primary treatment option.

Methods

The present study is a retrospective series of eight patients (six men and two women) diagnosed with obstructive hydrocephalus due to brain tumors treated with radiosurgery between April 2013 and February 2021. The primary endpoint of the present study is to report our institutional experience regarding the control of symptomatic obstructive hydrocephalus due to brain tumors treated with upfront radiosurgery.

Results

The mean age was 52 years (range, 5-79). The most common presenting symptoms included headache (100%), vision-related symptoms (75%), and ataxia (37.5%). All patients showed symptom improvement after radiosurgery, five (62.5%) patients showed resolution in less than three days and the rest of the patients resolved hydrocephalus in a longer timeframe (more than three days). All patients lowered their Evans index compared to the index documented before radiosurgery, in a range from 0.02 to 0.17.

Conclusion

Radiosurgery is a non-invasive alternative treatment for primary and secondary brain tumors that debut with obstructive hydrocephalus, tumors expected to have a high alpha/beta ratio might be suitable to attempt radiosurgery to avoid permanently implanted devices such as VP shunts or other invasive procedures such as a third ventriculostomy. The present study demonstrated that in selected cases SRS can lead to hydrocephalus symptom resolution along with a decrease in ventricular size in a relatively short time frame. Little evidence exists regarding the effect of SRS on symptomatic hydrocephalus resolution and further histology-specific studies are required. We acknowledge that this approach requires immediate access to radiosurgery and close clinical follow-up to ensure success.