Gamma knife surgery for idiopathic trigeminal neuralgia performed using a far-anterior cisternal target and a high dose of radiation

OBJECT: Gamma knife surgery (GKS) has emerged as a suitable treatment of pharmacologically resistant idiopathic trigeminal neuralgia. The optimal radiation dose and target for this therapy, however, remain to be defined. The authors analyzed the results of GKS in which a high dose of radiation and a distal target was used, to determine the best parameters for this treatment. METHODS: The authors evaluated results in 47 patients who were treated with this approach. All patients underwent clinical and magnetic resonance imaging examinations at 6 weeks, 6 months, and 1 year post-GKS. Fifteen potential prognostic factors associated with favorable pain control were studied. The mean follow-up period was 16 months (range 6-42 months). The initial pain relief was excellent (100% pain control) in 32 patients, good (90-99% pain control) in seven patients, fair (50-89% pain control) in three patients, and poor (< 50% pain control) in five patients. The actuarial curve of pain relief displayed a 59% rate of excellent pain control and a 71% excellent or good pain control at 42 months after radiosurgery. Radiosurgery-induced facial numbness was bothersome for two patients and mild for 18 patients. Three prognostic factors were found to be statistically significant factors for successful pain relief: a shorter distance between the target and the brainstem, a higher radiation dose delivered to the brainstem, and the development of a facial sensory disturbance after radiosurgery. CONCLUSIONS: To optimize pain control and minimize complications of this therapy, we recommend that the nerve be targeted at a distance of 5 to 8 mm from the brainstem.     

The significance of contrast blush on computed tomography in children with splenic injuries

Purpose

Most children and adults with blunt splenic injuries are treated nonoperatively by well-established management protocols. The “blush sign” is an active pooling of contrast material within or around the spleen seen during intravenous enhanced computed tomography (CT) scan. Adult treatment algorithms often include the “blush sign” as an indication for embolization or surgical intervention. This study was designed to evaluate the implications of the “blush sign” in children with blunt splenic injuries.

Methods

A review was performed of all children with blunt splenic injuries treated between January 1996 and December 2001 at a level I pediatric trauma center using an established solid organ injury protocol. The demographic, CT imaging, and outcome data were recorded. Treatment was categorized as operative or nonoperative. A single pediatric radiologist retrospectively reviewed all available CT scans to confirm injury grade and the presence or absence of a “blush sign.”

Results

There were 133 eligible children admitted with blunt splenic trauma, with a mean age of 9.1 years (range, 1 to 15), including 86 children with an abdominal CT available for review. A “blush sign” on initial CT scan was noted in 6 children, all with grade 3 or above splenic injuries, 5 of who were treated nonoperatively. In this series, the single child with a “blush sign” who did not respond to nonoperative treatment had a severe polytrauma requiring urgent splenectomy and left nephrectomy. None of the children died of their splenic injury.

Conclusions

Although associated with higher grades of injury, the blush sign did not mandate embolization or surgical intervention in children with blunt splenic trauma in this series. Severe splenic injuries with a blush sign on the initial CT scan may be successfully treated nonoperatively when using an established treatment protocol. Management should be based primarily on physiological response to injury rather than the radiologic features of the injury.     

Blunt renal injuries in children can be managed nonoperatively: outcome in a consecutive series of patients

BACKGROUND: Nonoperative management of radiographically defined solid organ injuries has proven highly successful in children with blunt splenic and hepatic injuries. The role of nonoperative management protocols is less well defined for blunt renal injuries. The purpose of this study was to review the management and outcome of a consecutive series of children with blunt renal injury. METHODS: The trauma registry from a Level I pediatric trauma center was reviewed to identify all children (age < 19 years) who were treated for a blunt renal injury for the period January 1995 through December 2002. Demographic, anatomic, physiologic, management, and outcome data were analyzed. RESULTS: For the 8 years of review, 101 children with a blunt renal injury were identified, including 95 with accessible and complete data. The renal injury population had a mean age of 10.4 years (range, 0.5-18 years) and was 72.6% male. The renal injuries were distributed as follows: grade 1, n = 22; grade 2, n = 40; grade 3, n = 20; grade 4, n = 11; and grade 5, n = 2. Hematuria was present in 88.1% of children (in whom urinalysis results were available). Four children had underlying congenital renal anomalies. The mean hospital length of stay and intensive care unit stay were 6.0 and 2.6 days, respectively. Overall, 5 children (5.3%) required laparotomy, including 1 nephrectomy (isolated grade 4 injury) and 1 renorrhaphy, for an overall renal salvage rate of 98.9%. In children with isolated renal injuries (n = 48), one child (2.1%) required laparotomy. Seven children required adjunctive urologic procedures (ureteral stenting, n = 5; cystoscopy/cystogram, n = 2). There were seven deaths (7.4% overall; five because of head injury and two because of severe abdominal bleeding at presentation). CONCLUSION: A nonoperative management strategy was advantageous and successful in pediatric blunt renal injuries (94.7% successful nonoperative rate, 98.9% renal salvage rate). Adjunctive urologic procedures (e.g., ureteral stenting) were beneficial in selected cases.     

The incubation period of acute retroviral syndrome as a multistep process: a parametric survival analysis

A long duration of acute retroviral syndrome (ARS) and a short incubation of ARS (IncARS) are independent predictors of a fast progression to AIDS. The first objective of this study was to validate previous estimates of IncARS by comparing durations between health care workers (HCWs) accidentally infected by HIV and individuals infected by other routes (non-health care workers [N-HCWs]). The second objective was to use parametric survival models to generate hypotheses on various steps occurring during the IncARS. Data from a prospective cohort of patients with documented ARS and from individuals with ARS as the result of accidental exposure to HIV were analyzed. Nonparametric and parametric survival models were used to describe the incubation of ARS. No differences were found for the median IncARS between 34 HCWs (21.5 days) and 70 N-HCWs (21.5 days) (log-rank test, P = 0.72). According to survival models, IncARS can be modeled with a gamma and/or lognormal model with means of 26.4 days and 26.7 days, respectively. The gamma model suggests that 3 sequential stages are present during the IncARS, which is compatible with basic science investigations identifying crossing of the epithelial barrier by the virus, the virus-host cell interactions, and the viral systemic dissemination.     

Brief report: health beliefs among survivors of childhood cancer

OBJECTIVE: To describe interest in cancer screening and tobacco-control procedures (nicotine-addiction susceptibility testing) among survivors of childhood cancer and to identify psychosocial modifying and readiness factors associated with survivors' interest, based on the children's health belief model. METHODS: Twenty-eight survivor-mother dyads were interviewed as part of a preliminary study (mean age of survivors = 15.4 years at time of interview, 10.1 years at time of diagnosis, and 12.0 years at end of treatment); interviews consisted of well-validated self-report items and measures of health beliefs. RESULTS: In sum, 57% and 61% of survivors were interested in screening and susceptibility testing, respectively. Survivors who rated themselves as more competent, more concerned about cancer, and more vulnerable to cancer were more interested in participating in screening. Regarding interest in nicotine-addiction susceptibility testing, survivors were more interested when they perceived greater vulnerability to the harm of smoking and when they had mothers who perceived themselves to be in better health. CONCLUSIONS: Preliminary data suggest that psychosocial modifying and readiness factors are associated with survivors' interest in cancer screening and tobacco-control procedures and that additional research in this area is warranted.     

Increased perception of loudness in autism

Clinical reports on autism describe abnormal responses to auditory stimuli such as intolerance to sounds. The present study assessed subjective perception of loudness in subjects with autism compared to healthy controls, using two psychoacoustic tests. First, the auditory dynamic range was evaluated at six different tone frequencies. Secondly, loudness growth as a function of the intensity level of a 1 kHz tone was estimated. Verbal responses from a group of 11 children and adolescents with autism were compared to responses of 11 age- and gender- matched healthy controls. Smaller auditory dynamic ranges were found in the autistic group than in the control group, as well as increased perception of loudness, indicating hyperacusis in subjects with autism.