Search Results

You are looking at 1 - 10 of 122 items for

  • Author or Editor: David W. Roberts x
Clear All Modify Search
Full access

David W. Roberts

Restricted access

S. Scott Lollis and David W. Roberts

Object

Robotic applications hold great promise for improving clinical outcomes and reducing complications of surgery. To date, however, there have been few widespread applications of robotic technology in neurosurgery. The authors hypothesized that image-guided robotic placement of a ventriculostomy catheter is safe, highly accurate, and highly reproducible.

Methods

Sixteen patients requiring catheter ventriculostomy for ventriculoperitoneal (VP) shunt or reservoir placement were included in this retrospective study. All patients underwent image-guided robotic placement of a ventricular catheter, using a preoperatively defined trajectory.

Results

All catheters were placed successfully in a single pass. There were no catheter-related hemorrhages and no injuries to adjacent neural structures. The mean distance of the catheter tip from the target was 1.5 mm. The mean operative times were 112 minutes for VP shunt placement and 42.3 minutes for reservoir placement. The mean operative times decreased over the course of the study by 49% for VP shunts and by 19% for reservoir placement.

Conclusions

The robotic placement of a ventriculostomy catheter using a preplanned trajectory is safe, highly accurate, and highly reliable. This makes single-pass ventriculostomy possible in all patients, even in those with very small ventricles, and may permit catheter-based therapies in patients who would otherwise be deemed poor surgical candidates because of ventricle size. Robotic placement also permits careful preoperative study and optimization of the catheter trajectory, which may help minimize the risks to bridging veins and sulcal vessels.

Restricted access

Robert E. Harbaugh, David W. Roberts and Jonathan D. Fratkin

✓ A 44-year-old woman presented with intraventricular hemorrhage and a calcified avascular mass lesion in the anterior third ventricle. This lesion proved to be a densely calcified variant of cavernous hemangioma, namely, hemangioma calcificans. Twelve previous cases of this lesion have been reported in the neurosurgical literature. Association with spontaneous intraventricular hemorrhage has not been previously reported. The clinical presentation, radiological appearance, surgical findings, and histopathology of this lesion are discussed and a brief review of the literature is presented.

Full access

Linton T. Evans, Richard Morse and David W. Roberts

Seizures are the initial manifestation of tuberous sclerosis complex (TSC) in 90% of individuals. The prevalence of epilepsy in TSC is 80%–90% with a large proportion refractory to antiepileptic drugs. A review of the literature of epilepsy surgery in TSC demonstrates impressive success rates for seizure-free outcomes. These studies describe a number of novel noninvasive methods for seizure localization including PET, SPECT, and magnetoencephalography. Additionally, there is a subset of patients with TSC with bilateral, multifocal, or generalized epileptiform discharges that would have previously been excluded from resection. New developments in neuroimaging and invasive monitoring with intracranial electrodes are useful methods in identifying an epileptogenic tuber in these individuals with refractory epilepsy. The authors offer a survey of the literature and description of these methods. Additionally they present an illustrative case of ictal SPECT and intracranial electroencephalography used in the preoperative evaluation of a 10-year-old girl with intractable seizures and TSC. This patient ultimately underwent resection of an epileptogenic region within the occipital lobe.

Full access

Henry J. Riordan, Laura A. Flashman and David W. Roberts

The purpose of this study was to characterize the neuropsychological and psychosocial profile of patients with Parkinson's disease before and after they underwent unilateral left or right pallidotomy, to assess specific cognitive and personality changes caused by lesioning the globus pallidus, and to predict favorable surgical outcome based on these measures. Eighteen patients underwent comprehensive neuropsychological assessment before and after left-sided pallidotomy (10 patients) or right-sided pallidotomy (eight patients). The findings support the presence of frontosubcortical cognitive dysfunction in all patients at baseline and a specific pattern of cognitive impairment following surgery, with side of lesion being an important predictor of pattern and degree of decline. Specifically, patients who underwent left-sided pallidotomy experienced a mild decline on measures of verbal learning and memory, phonemic and semantic verbal fluency, and cognitive flexibility. Patients who underwent right-sided pallidotomy exhibited a similar decline in verbal learning and cognitive flexibility, as well as a decline in visuospatial construction abilities; however, this group also exhibited enhanced performance on a delayed facial memory measure. Lesioning the globus pallidus may interfere with larger cognitive circuits needed for processing executive information with disruption of the dominant hemisphere circuit, resulting in greater deficits in verbal information processing. The left-sided pallidotomy group also reported fewer symptoms of depression and anxiety following surgery. This enhanced mood functioning was not seen for the right-sided pallidotomy group. No relationships were noted between cognitive impairment or advanced age at baseline and surgical outcome. This study provides objective evidence for specific changes in neurocognitive and psychosocial functioning following left- and right-sided pallidotomy.

Restricted access

David W. Roberts

Full access

Symeon Missios, Kimon Bekelis and David W. Roberts

Paul of Aegina (625–690 AD) was born on the island of Aegina and was one of the most prominent physician-writers of the Byzantine Empire. His work Epitome of Medicine, comprised of 7 books, was a comprehensive compendium of the medical and surgical knowledge of his time and was subsequently translated into multiple languages. Paul of Aegina made valuable contributions to neurosurgical subjects and described procedures for the treatment of nerve injuries, hydrocephalus, and fractures of the skull and spine. His work combined the ancient knowledge of Hippocrates and Galen with contemporary medical observations and served as a bridge between Byzantine and Arabic medicine. He is considered to be one of the great ancient Greek medical writers and his work has influenced the subsequent evolution of Western European and Arab medicine. This paper provides an account of his contribution to the management of neurosurgical pathologies during the Byzantine era, as described in his medical compendium, Epitome of Medicine.

Restricted access

Terrance M. Darcey and David W. Roberts

Object

The anatomical localization of electrodes in the human brain is important for the interpretation of pathophysiological (epileptifom spikes, seizures) and functional data (stimulation mapping, evoked potentials). Electroencephalography and evoked potentials are volume-conducted field effects that are most easily interpreted with knowledge of the location and topology of adjacent structures, and brain stimulation techniques produce current fields whose effects are highly dependent on the geometry of electrode assemblies in relation to adjacent structures. In this paper, the authors describe a straightforward method for implanted electrode localization, and detail their experience to date with the technique.

Methods

The described method is based on the coregistration of preoperative MR imaging studies with postimplant CT scans by using standard mutual information optimization of rigid body transformation of the CT to the MR image. Fused images of the MR and thresholded CT images are derived, and electrodes are visualized using various standard computer projections, renderings, and measurement tools.

Results

The authors have successfully used the described method over an extended period to localize electrode contacts in intracranial implants for seizure localization, and in long-term implants for movement disorders and seizure control. The accuracy of localization is very good, although it is dependent on image quality and possible brain shift between acquisition of the CT and MR images.

Conclusions

This method is easily implemented and is useful for a wide variety of clinical and research applications. It is a straightforward process to extend it to additional image modalities that are emerging for surgical planning and image guidance.