75 years of neurosurgery at the University of Minnesota.

Neurosurgery began as a distinct discipline at the University of Minnesota in 1937 with the appointment of William Peyton as head of the division. Under the leadership of Peyton, Lyle French, and Shelley Chou, the Department rose to national prominence. Substantial contributions included the introduction of dexamethasone to the practice of neurosurgery by Galicich and French, early procedures for the transthoracic correction of spinal deformity, important contributions to the understanding of brain death, the early laboratory work that led to the development of nimodopine, one of the first intraoperative magnetic resonance imaging facilities in the United States (1996), and the training of many academic neurosurgeons and department chairmen. The challenges of managed care and more recent changes in the health care system have been met, and the Department is a thriving clinical, educational, and research center for 21st-century neurosurgery.

Hemispherectomy for intractable epilepsy in adults: the first reported series.

Hemispherectomy for intractable unihemispheric epilepsy (IUE) has long been established in pediatric patients. This study reports the first series examining hemispherectomy exclusively in adult patients (>18 years old). Nine adults with IUE underwent hemispherectomy at the University of Minnesota. All patients had unilateral hemiplegia and visual field loss. Seven patients (77.8%) were Engel class I/II at last follow-up. Five (83.3%) of the six patients with >30 years of follow-up were seizure free. No surgery-related mortality, hydrocephalus, or superficial cerebral hemosiderosis occurred. Hemispherectomy is an effective procedure in appropriately selected adult patients, resulting in excellent long-term seizure control and no mortality.

Weight and body mass index in Parkinson's disease patients after deep brain stimulation surgery.

A retrospective chart review characterizing changes in 17 male and 10 female Parkinson's disease (PD) patients undergoing deep brain stimulation (DBS) surgery indicated that 6 mo before surgery, patients lost a mean of 5.1 lbs, whereas in the 6 mo after surgery, subjects gained a mean of 10.1 lbs; 22% gained more than 14 lbs. In 10 patients followed an additional 6 mo, weight gain continued. This weight gain may be associated with decreased energy expenditure due to subsidence of chronic tremor. The magnitude of gain underscores the need for proactive management of body weight in PD patients undergoing DBS.

The initial use of free-running electromyography to detect early motor tract injury during resection of intramedullary spinal cord lesions.

OBJECTIVE: The resection of intramedullary spinal cord lesions (ISCLs) can be complicated by neurological deficits. Neuromonitoring has been used to reduce intraoperative risk. We have used somatosensory evoked potentials (SEPs) and muscle-derived transcranial electrical motor evoked potentials (myogenic TCE-MEPs) to monitor ISCL removal. We report our retrospective experience with the addition of free-running electromyography (EMG). METHODS: Thirteen patients underwent 14 monitored ISCL excisions. Anesthesia was maintained with minimal inhalant to reduce motoneuron suppression and enhance the myogenic TCE-MEPs. Free-running EMG was examined in the four limbs for evidence of abnormal bursts, prolonged tonic discharge, or sudden electrical silence. Warning of an electromyographic abnormality or myogenic TCE-MEP loss prompted interventions, including blood pressure elevation, a pause in surgery, a wake-up test, or termination of surgery. Pre- and postoperative neurological examinations determined the incidence of new deficits. RESULTS: The combined use of free-running EMG and myogenic TCE-MEPs detected all eight patients with a new motor deficit after surgery; there was one false-positive report. In three of the eight true-positive cases, an electromyographic abnormality immediately anticipated loss of the myogenic TCE-MEPs. Two patients with abnormal EMGs but unchanged myogenic TCE-MEPs experienced mild postoperative worsening of motor deficits; myogenic TCE-MEPs alone would have generated false-negative reports in these cases. CONCLUSION: During resection of ISCLs, free-running EMG can supplement motor tract monitoring by TCE-MEPs. Segmental and suprasegmental elicitation of neurotonic discharges can be observed in four-limb EMG. Abnormal electromyographic bursts, tonic discharge, or abrupt electromyographic silence may anticipate myogenic TCE-MEP loss and predict a postoperative motor deficit.

Bilateral subthalamic nucleus stimulation for the treatment of Parkinson's disease: results of six patients.

In this study, researchers evaluated the effect of bilateral subthalamic nucleus stimulation on various measures of Parkinson's disease. Assessments were completed before and after surgery in a double-blind fashion under the following six conditions: (a) on medication, (b) off medication, (c) on medication/on stimulation, (d) on medication/off stimulation, (e) off medication/on stimulation, and (f) off medication/off stimulation. On average, improvement was noted in all areas including the Unified Parkinson's Disease Rating Scale, Schwab and England Activities of Daily Living Scale, Modified Hoehn and Yahr Staging, and timed tests: In addition, dyskinesia duration and dyskinesia disability were reduced.