Ahead of Print: Endoscopic Approach to Pontine Cavernoma

Background and Importance: Hemorrhagic, symptomatic cavernous malformations in the brainstem are difficult to access. Conventional approaches such as the transpetrosal approach often require significant brain retraction. We present the successful purely endoscopic, endonasal, transclival resection of a symptomatic cavernoma located in the ventromedial pons.

Clinical Presentation: A 17-year-old male presented with acute onset of headache, facial numbness, and tingling. Magnetic resonance imaging demonstrated an enhancing lesion in the pons consistent with a cavernous malformation. Over the course of the next 3 weeks the patient had 2 additional episodes of acutely worsening neurological deficits leaving him with left-sided hemiparesis, a right 6th nerve palsy, and dysphagia. A purely endoscopic endonasal, transclival, approach was used to resect the cavernoma. Post-operatively he had a transient worsening of his left sided motor function and restricted horizontal gaze, but at last follow-up his hemiparesis had improved and his MRI demonstrated a radiographic cure. He did develop a CSF leak despite prophylactic lumbar CSF drainage for two days and use of bilateral vascularized nasoseptal flaps. The CSF leak was repaired with CSF diversion and a second surgical procedure; at last follow-up he had no recurrence of the leak.

Ahead of Print: Endoscopic Approach to Pontine Cavernoma

Background and Importance: Hemorrhagic, symptomatic cavernous malformations in the brainstem are difficult to access. Conventional approaches such as the transpetrosal approach often require significant brain retraction. We present the successful purely endoscopic, endonasal, transclival resection of a symptomatic cavernoma located in the ventromedial pons.

Clinical Presentation: A 17-year-old male presented with acute onset of headache, facial numbness, and tingling. Magnetic resonance imaging demonstrated an enhancing lesion in the pons consistent with a cavernous malformation. Over the course of the next 3 weeks the patient had 2 additional episodes of acutely worsening neurological deficits leaving him with left-sided hemiparesis, a right 6th nerve palsy, and dysphagia. A purely endoscopic endonasal, transclival, approach was used to resect the cavernoma. Post-operatively he had a transient worsening of his left sided motor function and restricted horizontal gaze, but at last follow-up his hemiparesis had improved and his MRI demonstrated a radiographic cure. He did develop a CSF leak despite prophylactic lumbar CSF drainage for two days and use of bilateral vascularized nasoseptal flaps. The CSF leak was repaired with CSF diversion and a second surgical procedure; at last follow-up he had no recurrence of the leak.

Ahead of Print: High-Definition Fiber Tractography of the Human Brain

Background: High Definition Fiber Tracking (HDFT) is a novel combination of processing, reconstruction, and tractography methods that can track white matter fibers from cortex, through complex fiber crossings, to cortical and subcortical targets with sub-voxel resolution.

Objective: To perform neuroanatomical validation of HDFT and investigate its neurosurgical applications.

Methods: Six neurologically healthy adults and 36 patients with brain lesions were studied. Diffusion Spectrum Imaging (DSI) data were reconstructed using a Generalized Q-Ball Imaging (GQI) approach. Fiber dissection studies were performed in 20 human brains and selected dissection results were compared with tractography.

Video: Endoscopic Approach to Pontine Cavernoma

This video demonstrates surgical technique for endoscopic, endonasal, transclival resection of a pontine cavernoma.

Ahead of Print: A Proposed Grading System of Brain and Spinal Cavernomas

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BACKGROUND: Most cavernomas in the CNS are characterized by a benign natural course. Progressive symptoms warrant surgical removal. In the literature, the factors affecting long-term postoperative outcome are not statistically well confirmed.

OBJECTIVE: We performed a multifactorial analysis of risk factors on a large patient series and utilized the results to propose a simple grading scale to predict outcome.

METHODS: We studied 303 consecutive patients with cavernomas treated surgically at our department from 1980-2009. Follow-up assessment was performed on average 5.7 years postoperatively (range 0.2 – 36 yrs). The main outcome measure was patients’ condition at the last follow-up on Glasgow Outcome Scale (GOS). For statistical analysis, the outcome measure was dichotomized to favorable (GOS 5) and unfavorable (GOS 1-4). Binary logistic regression analysis was used to estimate the effect of age, gender, seizures, pre-existing neurological deficits, hemorrhage, size and location of cavernoma on long-term outcome.