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Michael Turner, Ha Son Nguyen and Aaron A. Cohen-Gadol


The aim of this study was to identify the benefits of intraventricular baclofen (IVB) therapy for the treatment of intractable spasticity or dystonia in a subset of patients who had experienced multiple revisions while receiving intrathecal baclofen (ITB) therapy.


The authors reviewed the charts of 22 consecutive patients with intractable spasticity or dystonia who initially underwent ITB therapy, subsequently suffered multiple revisions during ITB therapy, and ultimately received IVB therapy, all during a 12-year period from November 1998 to October 2010. The intraventricular catheters were positioned in the lateral ventricle, aided by stereonavigation.


The surgical revision rate (the average number of surgical revisions per average number of follow-up years) during ITB therapy was 0.84, and was 0.50 during IVB therapy. The most frequent complication requiring surgical revision during ITB therapy was catheter occlusion, followed by pump malfunction/pump pocket issues, and infection. The most frequent complication requiring surgical revision during IVB therapy was infection, followed by catheter misplacement/migration. Four patients suffered infection that required removal of their intraventricular catheter, and currently have no baclofen system.


Some of these patients had a history of increasing revisions with increasing frequency during ITB therapy. Such a history puts them at risk for spinal arachnoiditis, a condition that complicates further ITB therapy. For such patients, the authors believe that IVB therapy may be a beneficial therapeutic option, given that the surgical revision rate was lower for IVB than for ITB. Intraventricular baclofen may be a cost-effective option for patients with mounting revisions during ITB therapy.

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Ha Son Nguyen, Luyuan Li, Mohit Patel, Shekar Kurpad and Wade Mueller


The presence, extent, and distribution of intraventricular hemorrhage (IVH) have been associated with negative outcomes in aneurysmal subarachnoid hemorrhage (SAH). Several qualitative scores (Fisher grade, LeRoux score, and Graeb score) have been established for evaluating SAH and IVH. However, no study has assessed the radiodensity within the ventricular system in aneurysmal SAH patients with IVH. Prior studies have suggested that hemorrhage with a higher radiodensity, as measured by CT Hounsfield units, can cause more irritation to brain parenchyma. Therefore, the authors set out to investigate the relationship between the overall radiodensity of the ventricular system in aneurysmal SAH patients with IVH and their clinical outcome scores.


The authors reviewed the records of 101 patients who were admitted to their institution with aneurysmal SAH and IVH between January 2011 and July 2015. The following data were collected: age, sex, Glasgow Coma Scale (GCS) score, Hunt and Hess grade, extent of SAH (none, thin, or thick/localized), aneurysm location, and Glasgow Outcome Scale (GOS) score. To evaluate the ventricular radiodensity, the initial head CT scan was loaded into OsiriX MD. The ventricular system was manually selected as the region of interest (ROI) through all pertinent axial slices. After this, an averaged ventricular radiodensity was calculated from the ROI by the software. GOS scores were dichotomized as 1–3 and 4–5 subgroups for analysis.


On univariate analysis, younger age, higher GCS score, lower Hunt and Hess grade, and lower ventricular radiodensity significantly correlated with better GOS scores (all p < 0.05). Subsequent multivariate analysis yielded age (OR 0.936, 95% CI 0.895–0.979), GCS score (OR 3.422, 95% CI 1.9–6.164), and ventricular density (OR 0.937, 95% CI 0.878–0.999) as significant independent predictors (p < 0.05). A receiver operating characteristic curve yielded 12.7 HU (area under the curve 0.625, p = 0.032, sensitivity = 0.591, specificity = 0.596) as threshold between GOS scores of 1–3 and 4–5.


This study suggests that the ventricular radiodensity in aneurysmal SAH patients with IVH, along with GCS score and age, may serve as a predictor of clinical outcome.

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Michael S. Turner, Ha Son Nguyen, Troy D. Payner and Aaron A. Cohen-Gadol


Posterior fossa cysts are usually divided into Dandy-Walker malformations, arachnoid cysts, and isolated and/or trapped fourth ventricles. Shunt placement is a mainstay treatment for decompression of these fluid collections when their expansion becomes symptomatic. Although several techniques to drain symptomatic posterior fossa cysts have been described, each method carries its own advantages and disadvantages. This article describes an alternative technique.


In 10 patients, the authors used an alternative technique involving stereotactic and endoscopic methods to place a catheter in symptomatic posterior fossa cysts across the tentorium. Discussion of these cases is included, along with a review of various approaches to shunt placement in this region and recommendations regarding the proposed technique.


No patient suffered intracranial hemorrhage related to the procedure and catheter implantation. All 3 patients who underwent placement of a new transtentorial cystoperitoneal shunt and a new ventriculoperitoneal shunt did not suffer any postoperative complication; a decrease in the size of their posterior fossa cysts was evident on CT scans obtained during the 1st postoperative day. Follow-up CT scans demonstrated either stable findings or further interval decrease in the size of their cysts. In 1 patient, the postoperative head CT demonstrated that the transtentorial catheter terminated posterior to the right parietal occipital region without entering the retrocerebellar cyst. This patient underwent a repeat operation for proximal shunt revision, resulting in an acceptable catheter implantation. The patient in Case 8 suffered from a shunt infection and subsequently underwent hardware removal and aqueductoplasty with stent placement. The patient in Case 9 demonstrated a slight increase in fourth ventricle size and was returned to the operating room. Exploration revealed a kink in the tubing connecting the distal limb of the Y connector to the valve. The Y connector was replaced with a T connector, and 1 week later, CT scans exhibited interval decompression of the ventricles. This patient later presented with cranial wound breakdown and an exposed shunt. His shunt hardware was removed and he was treated with antibiotics. He later underwent reimplantation of a lateral ventricular and transtentorial shunt and suffered no other complications during a 3-year follow-up period.


The introduction of endoscopic and stereotactic techniques has expanded the available treatment possibilities for posterior fossa cysts.

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Ha Son Nguyen, Seema Vishnu Sundaram, Kristine M. Mosier and Aaron A. Cohen-Gadol

Much has been reported regarding the technique of performing an awake craniotomy with cortical mapping for the functional cortex responsible for sensorimotor activity and language. However, documentation for mapping the visual cortex during an awake craniotomy with a description of its technical details is rare. The authors report the case of a patient who underwent an awake craniotomy with mapping of the visual cortex to remove a glioma situated in the left medial occipital lobe. The techniques that made such a mapping procedure possible are discussed.

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Ahmed J. Awad, Ha S. Nguyen, Elsa Arocho-Quinones, Ninh Doan, Wade Mueller and Sean M. Lew

Approximately one-third of patients with epilepsy are resistant to medical therapy, particularly in those with mesial temporal lobe epilepsy. While there are several surgical modalities, efforts have been focused on developing safer and minimally invasive techniques. In this video, the authors present the case of a 45-year-old woman with a 2-year history of refractory left mesial temporal lobe epilepsy who underwent MRI-guided laser ablation of amygdala and hippocampus. There were no perioperative complications.

The video can be found here:

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Oral Presentations

2010 AANS Annual Meeting Philadelphia, Pennsylvania May 1–5, 2010