✓ The authors report on a patient who developed acute-onset paraparesis after underoing a thoracotomy 40 years earlier for a carcinoid adenoma. No infectious or neoplastic origin could be found to explain the patient's current clinical course and radiographic findings. The postoperative events in this case are discussed, as well as the literature regarding postthoracotomy complications.
Jason A. Heth, Matthew A. Howard III and Nicholas Rossi
Taylor J. Abel, Timothy Walch and Matthew A. Howard III
Advances in functional neurosurgery, including neuromodulation and more recently ultrasonic ablation of basal ganglia structures, have improved the quality of life for patients with debilitating movement disorders. What is little known, however, is that both of these neurosurgical advances, which remain on the cutting edge, have their origin in the pioneering work of Russell Meyers, whose contributions are documented in this paper. Meyers' published work and professional correspondence are reviewed, in addition to documents held by the Department of Neurosurgery at the University of Iowa. Meyers was born in Brooklyn, New York, and received his neurosurgical training at hospitals in New York City under Jefferson Browder. In 1939, a chance encounter with a young woman with damaged bilateral ventral striata convinced Meyers that the caudate could be resected to treat Parkinsonism without disrupting consciousness. Shortly thereafter, he performed the first caudate resection for postencephalitic Parkinsonism. In 1946, Meyers became the first chairman of neurosurgery at the State University of Iowa (now the University of Iowa), which led to the recruitment of 8 faculty members and the training of 18 residents during his tenure (1946–1963). Through collaboration with the Fry brothers at the University of Illinois, Meyers performed the first stereotactic ultrasonic ablations of deep brain structures to treat tremor, choreoathetosis, dystonia, intractable pain, and hypothalamic hamartoma. Meyers left academic neurosurgery in 1963 for reasons that are unclear, but he continued clinical neurosurgery work for several more years. Despite his early departure from academic medicine, Meyers' contributions to functional neurosurgery provided a lasting legacy that has improved the lives of many patients with movement disorders.
Timothy W. Vogel, Brian J. Dlouhy and Matthew A. Howard III
The object of this study was to evaluate the causes of plunging events associated with automatic-releasing cranial perforators at the authors' institution.
The authors analyzed a consecutive series of 1652 cranial procedures involving one type of automaticreleasing cranial perforator over a 2-year period. Plunging occurrences were recorded for 2 drill speeds: 1000 rpm in the 1st year and 800 rpm during the 2nd year. Intraoperative observations, neuroimaging studies, and clinical data were evaluated for each plunging event.
The authors identified 9 plunging events for an overall incidence of 0.54%. In the 1st year, they identified 2 plunging events at a speed of 1000 rpm for an incidence of 0.19%. In an effort to reduce this occurrence, the speed of the drill was lowered to 800 rpm. There were 7 additional events, for a significantly increased incidence of 1.16% (p = 0.014, Fisher exact test) after the change was implemented. These cases spanned a number of procedures in adults and pediatric patients, including ventriculostomy placement, craniotomies for tumor resection, tumor biopsy, and endoscopic third ventriculostomy. Despite plunging, no immediate postoperative complications were noted on clinical examination.
While technology continues to improve cranial perforator performance, the use of such a device is still associated with a risk of complications causing dural lacerations and injury to the underlying cortex. Decreasing the drill speed may not decrease the incidence of plunging.
Timothy W. Vogel, Brian J. Dlouhy and Matthew A. Howard III
Spontaneous intracranial hypotension (SIH) is a syndrome with serious neurological sequelae. As demonstrated by the following report, recurrent episodes of SIH can be difficult to diagnose when associated with other neurosurgical procedures, such as craniectomies. In this paper, the authors demonstrate SIH presenting as a subdural hematoma with recurrence of CSF leaks. Spontaneous intracranial hypotension was further complicated by paradoxical herniation following a craniectomy. Treatment of SIH necessitated multiple epidural blood patches for CSF leaks at different spinal levels and at different times. The efficacy of each epidural blood patch was confirmed with radionuclide imaging. Confirmation of effective blood patch placement may be useful for identifying patients at risk for a failed epidural blood patch or for patients whose neurological examination results have not fully improved.
Matthew A. Howard III, Ralph G. Dacey Jr. and H. Richard Winn
✓ Animal models of Parkinson's disease and Alzheimer's disease have shown dramatic functional improvement after transplantation of embryonic neurons into denervated regions of the adult brain. Because of the ethical and logistic problems associated with the use of human embryonic brain tissue, cross-species transplants are an attractive alternative. An experimental model of cross-species brain transplantation was developed to evaluate cell survival in untreated and cyclosporin A (CyA)-treated animals. Cholinergic ventral neurons from embryonic mice were transplanted into the frontal lobes of 18 adult Sprague-Dawley rats using a cell suspension technique. Nine animals were treated for 13 days with CyA (10 mg/kg/day) and nine were not treated. Twelve weeks after transplantation, frozen sections through the transplant volume were obtained. Alternate sections were prepared with hematoxylin and eosin and acetylcholine esterase stains. Cell counts through a 2-cu mm volume incorporating the transplant were compared to a contralateral control volume. Eight of the nine untreated transplants were successful (mean transplant cells ± standard error of the mean: 90.7 ± 19.4/2 cu mm). All of the nine CyA-treated transplants survived, with mean transplant count 28.7 cells/2 cu mm greater than untreated transplants (mean increase 28.7: p ≤ 0.05, Wilcoxon matched-pairs signed ranks test). It is concluded that: 1) this model is useful for quantitating transplant cell survival; 2) untreated xenografts survive well; and 3) a 13-day course of CyA improved long-term graft survival.
Kirsten E. Stoner, Kingsley O. Abode-Iyamah, Vincent A. Magnotta, Matthew A. Howard III and Nicole M. Grosland
Cervical myelopathy (CM) is a common and debilitating form of spinal cord injury caused by chronic compression; however, little is known about the in vivo mechanics of the healthy spinal cord during motion and how these mechanics are altered in CM. The authors sought to measure 3D in vivo spinal cord displacement and strain fields from MR images obtained during physiological motion of healthy individuals and cervical myelopathic patients.
Nineteen study participants, 9 healthy controls and 10 CM patients, were enrolled in the study. All study participants had 3T MR images acquired of the cervical spine in neutral, flexed, and extended positions. Displacement and strain fields and corresponding principal strain were obtained from the MR images using image registration.
The healthy spinal cord displaces superiorly in flexion and inferiorly in extension. Principal strain is evenly distributed along the spinal cord. The CM spinal cord displaces less than the healthy cord and the magnitude of principal strain is higher, at the midcervical levels.
Increased spinal cord compression during cervical myelopathy limits motion of the spinal cord and increases spinal cord strain during physiological motion. Future studies are needed to investigate how treatment, such as surgical intervention, affects spinal cord mechanics.
Matthew A. Howard III, Jayashree Srinivasan, Carl G. Bevering, H. Richard Winn and M. Sean Grady
✓ Accurate placement of parietooccipital ventricular catheters can be difficult and frustrating. To minimize the morbidity of the procedure and lengthen the duration of shunt function, the catheter tip should lie in the ipsilateral frontal horn. The authors describe a posterior ventricular guide (PVG) for placement of parietooccipital catheters that operates by mechanically coupling the posterior burr hole to the anterior target point. In a series of 38 patients who underwent ventriculoperitoneal shunting with the assistance of the guide, postoperative computerized tomography (CT) scanning revealed that 35 (92.0%) had accurate catheter placement. In comparison, a retrospective review of free-hand posterior catheter placement revealed good catheter position in only 22 of 43 patients (51.1%). The use of the guide added less than 5 minutes to the entire procedure, and there were no complications related to its use. The PVG is a simple and useful tool that aids in the placement of parietooccipital ventricular catheters.
Matthew A. Howard III, Alan S. Gross, Ralph G. Dacey Jr. and H. Richard Winn
✓ Reports prior to 1980 describe overall mortality rates for acute subdural hematomas (SDH's) ranging from 40% to 90% with poor outcomes observed in all age groups. Recently, improved results have been reported with rapid diagnosis and surgical treatment. A relatively large number of older patients (34 patients over 65 years old) were treated recently at Harborview Medical Center, enabling a retrospective comparison with similarly treated younger patients (33 patients aged 18 to 40 years). Clinical information and computerized tomography morphometric data were obtained. Patients in the younger group were most often injured in motor-vehicle accidents (15 cases), whereas falls were most frequent in the older group (19 cases). Patients in both groups were rapidly resuscitated in the field; more than 30% were treated within 1 hour after the time of injury. Injury severity, determined by the admission Glasgow Coma Scale score, was similar for the two groups. Mean acute SDH volume was significantly larger in the older patients than in the younger group (mean ± standard deviation: 96.2 ± 117.2 vs. 21.6 + 27.7 cu cm), as was the amount of midline shift (1.2 ± 1.69 vs. 0.6 ± 0.75 cm). Surgical treatments were similar, but outcomes were dramatically different for the younger and older patients. Mortality rates were more than four times higher in older patients than in younger ones (74% vs. 18%). Three older patients and 25 younger patients were functional survivors. Old age, a larger SDH volume, and a larger midline shift all correlated with a poor outcome. The results of this study suggest that the pathophysiology of acute SDH varies with age, and that currently employed resuscitation and treatment methods have differentially improved the outcome for younger patients.
Hans E. Bakken, Hiroto Kawasaki, Hiroyuki Oya, Jeremy D. W. Greenlee and Matthew A. Howard III
✓ Neurosurgeons use invasive mapping methods during surgery to understand the functional neuroanatomy of patients. Electrical stimulation methods are used routinely for the temporary disruption of focal regions of cerebral cortex so that the surgeon may infer the functional role of the brain site being stimulated. Although it is an efficient and useful method, modes of electrical stimulation mapping have significant limitations. Neuroscientists use focal cooling to effect a more controlled disruption of cortical functions in experimental animals, and in this report, the authors describe their experience using a device to achieve this same objective in patients undergoing neurosurgery. The cooling probe consists of a stainless steel chamber with thermocouples and electroencephalography (EEG) recording contacts. Active cooling is achieved by infusing chilled saline into the chamber when the cooling probe is positioned on the pial surface. Experiments were performed in 18 patients. Temperature gradient measurements indicate that the entire thickness of gray matter under the probe is cooled to temperatures that disrupt local synaptic activity. Statistically significant changes in spontaneous and stimulusevoked EEG activity were consistently observed during cooling, providing clear evidence of reversible disruption of physiological functions. Preliminary findings during functional mapping of the Broca area demonstrated qualitative differences between the temporary neurological deficits induced by cooling and those caused by electrical stimulation. These findings indicate the safety and utility of the cooling probe as a neurosurgical research tool. Additional rigorously designed studies should be undertaken to correlate the effects of cooling, electrical stimulation, and focal lesioning.
Francis J. Jareczek, Marshall T. Holland, Matthew A. Howard III, Timothy Walch and Taylor J. Abel
Neurosurgery for the treatment of psychological disorders has a checkered history in the United States. Prior to the advent of antipsychotic medications, individuals with severe mental illness were institutionalized and subjected to extreme therapies in an attempt to palliate their symptoms. Psychiatrist Walter Freeman first introduced psychosurgery, in the form of frontal lobotomy, as an intervention that could offer some hope to those patients in whom all other treatments had failed. Since that time, however, the use of psychosurgery in the United States has waxed and waned significantly, though literature describing its use is relatively sparse. In an effort to contribute to a better understanding of the evolution of psychosurgery, the authors describe the history of psychosurgery in the state of Iowa and particularly at the University of Iowa Department of Neurosurgery. An interesting aspect of psychosurgery at the University of Iowa is that these procedures have been nearly continuously active since Freeman introduced the lobotomy in the 1930s. Frontal lobotomies and transorbital leukotomies were performed by physicians in the state mental health institutions as well as by neurosurgeons at the University of Iowa Hospitals and Clinics (formerly known as the State University of Iowa Hospital). Though the early technique of frontal lobotomy quickly fell out of favor, the use of neurosurgery to treat select cases of intractable mental illness persisted as a collaborative treatment effort between psychiatrists and neurosurgeons at Iowa. Frontal lobotomies gave way to more targeted lesions such as anterior cingulotomies and to neuromodulation through deep brain stimulation. As knowledge of brain circuits and the pathophysiology underlying mental illness continues to grow, surgical intervention for psychiatric pathologies is likely to persist as a viable treatment option for select patients at the University of Iowa and in the larger medical community.