✓ Microvascular decompression is preferred among open procedures for the treatment of trigeminal neuralgia. However, in some cases the decompression cannot be performed, either because no significant vascular compression of the trigeminal nerve is found at surgery or because a patient's vascular anatomy makes it unsafe. Partial sensory rhizotomy is a commonly used alternative in these instances. The outcome after partial sensory rhizotomy was reviewed retrospectively in 83 patients with an average follow-up period of 72 months. Sixty-four (77%) of these patients had no evidence of vascular contact at operation. The remaining 19 patients (23%) had vascular structures in proximity to the trigeminal nerve but still underwent partial sensory rhizotomy in place of or in addition to microvascular decompression either because the offending vessel could not be moved adequately (11 cases) or because the vascular contact was considered insignificant (eight cases). Outcome was classified as: excellent if there was no trigeminal neuralgia postoperatively; good if pain persisted or recurred but was less severe than preoperatively; and poor if persistent or recurrent pain was equal to or greater than the preoperative pain in severity and was refractory to medication, or was severe enough to require additional surgery. The outcome was excellent in 40 patients (48%), good in 18 (22%), and poor in 25 (30%); follow-up durations were similar for the three outcome categories. The failure rate was 17% for the 1st year and averaged 2.6% each year thereafter. Two variables were predictive of a poor outcome: prior surgery and lack of preoperative involvement of the third trigeminal division. Major complications occurred in 4% of cases and minor complications in 11%. The authors conclude that partial sensory rhizotomy is a safe and effective alternative to microvascular decompression when neurovascular compression is not identified at operation or when microvascular decompression cannot be performed for technical reasons.
Jacob N. Young and Robert H. Wilkins
Ronald F. Young and Robert B. King
✓ Using random sampling methods and the electron microscope we have verified the impression gained from light microscopy that unmyelinated fibers compose only about 40% of the total fiber count of the trigeminal root. By contrast, recent electron microscopic studies of segmental dorsal roots indicate that, at least in lower vertebrates, unmyelinated fibers compose up to 80% or more of the total. This observation is considered to be of descriptive rather than physiological or pathological significance. The morphological alterations that occur in the spinal trigeminal tract appear to restore the balance in favor of unmyelinated fibers at the functional termination of the trigeminal sensory root.
Ronald F. Young, Francisco Li, Sandra Vermeulen, and Robert Meier
The goal of this report was to describe the safety and effectiveness of nucleus ventralis intermedius (VIM) thalamotomy performed with the Leksell Gamma Knife (GK) for the treatment of essential tremor (ET).
One hundred seventy-two patients underwent a total of 214 VIM thalamotomy procedures with the Leksell GK between February 1994 and March 2007 for treatment of disabling ET. Eleven patients were lost to follow-up less than 1 year after the procedures, so that in this report the authors describe the results in 161 patients who underwent a total of 203 thalamotomies (119 unilateral and 42 bilateral).
There were statistically significant decreases (p < 0.0001) in tremor scores for both writing and drawing. The mean postoperative follow-up duration for all patients was 44 ± 33 months. Fifty-four patients have been followed for more than 60 months posttreatment. There were 14 patients who suffered neurological side effects that were temporary (6) or permanent (8), which accounted for 6.9% of the 203 treatments. All complications were related to lesions that grew larger than expected.
A VIM thalamotomy with the Leksell GK offers a safe and effective alternative for surgical treatment of ET. It is particularly applicable to patients who are not ideal candidates for deep brain stimulation but can be offered to all patients who are considering surgical intervention for ET.
Robert Dempsey, Robert P. Rapp, Byron Young, Sarah Johnston, and Phillip Tibbs
✓ Clean surgical procedures carry a risk of postoperative wound infection that is less than 5% in most hospitals. The use of prophylactic antibiotic agents in clean neurosurgical cases is controversial, and the neurosurgical literature through 1980 contains no controlled clinical trials to study its effectiveness in such cases. A report of 1732 consecutive procedures without a single postoperative wound infection in patients receiving systemic gentamicin, vancomycin, and streptomycin irrigation fluids is often quoted by neurosurgeons; however, these results have not yet been duplicated by others. Since 1980, there have been several controlled trials that support the use in clean neurosurgical cases of prophylactic antibiotics, including the vancomycin/gentamicin/streptomycin regimen and the first-generation cephalosporins. A report in 1986 of 1602 cases without a primary wound infection supports the use of a single perioperative dose of cefazolin. A review of causative organisms in postoperative wound infections demonstrates the preponderance of Gram-positive pathogens. Therefore, when antibiotic prophylaxis is indicated, adequate Gram-positive bacterial coverage, including protection against Staphylococcus infection, is required. With consideration of the present data, the cost of antibiotic therapy, and the danger of drug toxicity, a short perioperative regimen of cefazolin as prophylaxis is preferred in clean neurosurgical cases.
José Piquer, Mubashir Mahmood Qureshi, Paul H. Young, and Robert J. Dempsey
A shortage of neurosurgeons and a lack of knowledge of neuroendoscopic management of hydrocephalus limits modern care in sub-Saharan Africa. Hence, a mobile teaching project for endoscopic third ventriculostomy (ETV) procedures and a subsequent program to develop neurosurgery as a permanent specialty in Kenya and Zanzibar were created and sponsored by the Neurosurgery Education and Development (NED) Foundation and the Foundation for International Education in Neurological Surgery. The objective of this work was to evaluate the results of surgical training and medical care in both projects from 2006 to 2013.
Two portable neuroendoscopy systems were purchased and a total of 38 ETV workshops were organized in 21 hospitals in 7 different countries. Additionally, 49 medical expeditions were dispatched to the Coast General Hospital in Mombasa, Kenya, and to the Mnazi Moja Hospital in Zanzibar.
From the first project, a total of 376 infants with hydrocephalus received surgery. Six-month follow-up was achieved in 22%. In those who received follow-up, ETV efficacy was 51%. The best success rates were achieved with patients 1 year of age or older with aqueductal stenosis (73%). The main causes of hydrocephalus were infection (56%) and spina bifida (23%). The mobile education program interacted with 72 local surgeons and 122 nurses who were trained in ETV procedures. The second project involved 49 volunteer neurosurgeons who performed a total of 360 nonhydrocephalus neurosurgical operations since 2009. Furthermore, an agreement with the local government was signed to create the Mnazi Mmoja NED Institute in Zanzibar.
Mobile endoscopic treatment of hydrocephalus in East Africa results in reasonable success rates and has also led to major developments in medicine, particularly in the development of neurosurgery specialty care sites.
Byron Young, Robert P. Rapp, J. A. Norton, Dennis Haack, Phillip A. Tibbs, and James R. Bean
✓ The relationship between Glasgow Coma Scale (GCS) scores obtained during the 1st week after head injury and outcome at 1 year was analyzed in 170 patients. Seventy-two of 76 patients with initial GCS scores of higher than 7 had favorable outcomes. Only two of the 21 patients with initial GCS scores of 3 or 4 lived, and only one had a favorable outcome. Favorable and unfavorable outcomes were almost equally divided when the initial GCS scores were in the intermediate range of 5, 6, or 7. No patients with an initial GCS score in this intermediate range that subsequently worsened had a favorable outcome, while over 80% of those improving to a score higher than 7 had a favorable outcome. Only 12% of those persisting with a score of 5, 6, or 7 for 1 week had a favorable outcome.
Outcome predictions using the multiple logistic model were made for this intermediate group of patients based on GCS scores and data on midline shift derived from computerized tomography (CT). The patients with initial scores of 5, 6, or 7 with midline shifts of less than 4.1 mm on initial CT scanning had a significantly higher favorable outcome rate compared with patients with a larger shift. However, outcome predictions made by combining shift data and initial GCS scores are not significantly more accurate than predictions based solely on initial GCS scores. Combining 48-hour GCS scores and shift data significantly improves predictive accuracy based only on coma scores. The data obtained by combining GCS scores at 72 hours and 1 week and shift data is marginally significant for improving accuracy of outcome predictions. It is concluded that GCS scores and shift data are highly accurate indicators of outcome in head-injured patients.