Endoscopic fenestration of intraventricular cerebrospinal fluid cysts: the contralateral approach

OBJECTIVE: The endoscopic fenestration of intraventricular CSF cysts has evolved into a well-accepted treatment modality. However, definition of the optimal trajectory for endoscopic fenestration may be difficult. Distorted ventricular anatomy and poor visibility within the cyst due to its contents can make endoscopic fenestration challenging if approached from the ipsilateral side. In addition, transcortical approaches can theoretically cause injury to eloquent cortex, particularly in patients with dominant-sided lesions. The aim of this study was to examine the value of the contralateral transcortical transventricular approach in patients with dominant-sided ventricular cysts. METHODS: During a 5-year period between 2007 and 2011, 31 patients with intraventricular CSF cysts underwent surgery by the senior author (R.R.). Fourteen of these patients had cysts located on the dominant side. An image-guided endoscopic cyst fenestration via the contralateral transcortical transventricular approach was performed in 11 patients. A retrospective chart review was performed in all these patients to extract data on clinical presentation, operative technique, and surgical outcome. RESULTS: The most common presenting symptom was headache, followed by memory deficits and cognitive deterioration. In all cases CSF cysts were space occupying, with associated obstructive hydrocephalus in 8 patients. Image-guided endoscopic fenestration was successfully performed in all cases, with septum pellucidotomy necessary in 6 cases, and endoscopic third ventriculostomy in 1 case for additional aqueductal occlusion. Postoperative clinical outcome was excellent, with no associated permanent neurological or neuropsychological morbidity. No recurrent cysts were observed over a mean follow-up period of 2 years and 3 months. CONCLUSIONS: The contralateral approach to ventricular cysts can achieve excellent surgical outcomes while minimizing approach-related trauma to the dominant hemisphere. Careful case selection is essential to ensure that the contralateral endoscopic trajectory is the best possible exposure for sufficient cyst fenestration and restoration of CSF circulation

Proof of Concept: Wearable Augmented Reality Video See-Through Display for Neuro-Endoscopy

In mini-invasive surgery and in endoscopic procedures, the surgeon operates without a direct visualization of the patient’s anatomy. In image-guided surgery, solutions based on wearable augmented reality (AR) represent the most promising ones. The authors describe the characteristics that an ideal Head Mounted Display (HMD) must have to guarantee safety and accuracy in AR-guided neurosurgical interventions and design the ideal virtual content for guiding crucial task in neuro endoscopic surgery. The selected sequence of AR content to obtain an effective guidance during surgery is tested in a Microsoft Hololens based app

Glioblastoma surgery guided by 5-ALA fluorescence and subsequent i-MRI. A histological evaluation

Astrochronology is fundamental to many paleoclimate studies, but a standard statistical test has yet to be established for validating stand-alone astronomically tuned time scales (those lacking detailed independent time control) against their astronomical insolation tuning curves. Shackleton et al. (1995) proposed that the modulation of precession's amplitude by eccentricity can be used as an independent test for the successful tuning of paleoclimate data. Subsequent studies have demonstrated that eccentricity-like amplitude modulation can be artificially generated in random data, following astronomical tuning. Here we introduce a new statistical approach that circumvents the problem of introducing amplitude modulations during tuning and data processing, thereby allowing the use of amplitude modulations for astronomical time scale evaluation. The method is based upon the use of the Hilbert transform to calculate instantaneous amplitude following application of a wide band precession filter and subsequent low-pass filtering of the instantaneous amplitude to extract potential eccentricity modulations. Statistical significance of the results is evaluated using phase-randomized surrogates that preserve the power spectrum structure of the data but have randomized amplitude modulations. Application of the new testing algorithm to two astronomically tuned data sets demonstrates the efficacy of the technique and confirms the presence of astronomical signals. Additionally, it is demonstrated that a minimal tuning approach using (at maximum) one precession cycle per ~100 kyr eccentricity cycle does not introduce systematic frequency modulations, even when a narrow band-pass filter is applied, allowing direct comparison of data amplitudes and orbital eccentricity