Biomedical subjects

Eugene Huang

Publications and source records attributed to Eugene Huang.

16 recordsLinked to original sources

PubMed2006

Comparative proteomic analysis to study molecular events during gonad development in mice.

Sex determination represents a critical bifurcation in the road of embryonic development. It is based on a finely regulated network of gene activity, as well as protein-protein interactions and activation or silencing of signaling pathways. Despite the identification of a number of critical genes, many aspects of the molecular cascade that drives the differentiation of the embryonic gonad into either a testis or an ovary remain poorly understood. To identify new proteins involved in this cascade, we employed two-dimensional gel electrophoresis and mass spectrometry to compare the protein expression profiles of fetal mouse testes and ovaries. Three proteins, hnRPA1, TRA1, and HSC71, were found to be expressed in a male-specific manner and this expression was confirmed by real-time reverse transcriptase polymerase chain reaction (RT-PCR) and in situ hybridization. Moreover, HSC71 was found to be hyperphosphorylated in male compared to female gonads, emphasizing the advantage of the proteomic approach in allowing the detection of posttranslational modifications.

Animals↗

PubMed2006

Functional analysis of the triplex proteins (VP19C and VP23) of herpes simplex virus type 1.

The triplex of herpesvirus capsids is a unique structural element. In herpes simplex virus type 1 (HSV-1), one molecule of VP19C and two of VP23 form a three-pronged structure that acts to stabilize the capsid shell through interactions with adjacent VP5 molecules. The interaction between VP19C and VP23 was inferred by yeast cryoelectron microscopy studies and subsequently confirmed by the two-hybrid assay. In order to define the functional domains of VP19C and VP23, a Tn7-based transposon was used to randomly insert 15 bp into the coding regions of these two proteins. The mutants were initially screened for interaction in the yeast two-hybrid assay to identify the domains important for triplex formation. Using genetic complementation assays in HSV-1-infected cells, the domains of each protein required for virus replication were similarly uncovered. The same mutations that abolish interaction between these two proteins in the yeast two-hybrid assay similarly failed to complement the growth of the VP23- and VP19C-null mutant viruses in the genetic complementation assay. Some of these mutants were transferred into recombinant baculoviruses to analyze the effect of the mutations on herpesvirus capsid assembly in insect cells. The mutations that abolished the interaction in the yeast two-hybrid assay also abolished capsid assembly in insect cells. The outcome of these experiments showed that insertions in at least four regions and especially the amino terminus of VP23 abolished function, whereas the amino terminus of VP19C can tolerate transposon insertions. A novel finding of these studies was the ability to assemble herpesvirus capsids in insect cells using VP5 and VP19C that contained a histidine handle at their amino terminus.

Amino Acid Sequence↗

PubMed2004

Characterization of rectal normal tissue complication probability after high-dose external beam radiotherapy for prostate cancer.

PURPOSE: Conformal radiotherapy (RT) has allowed radiation dose escalation to improve the outcome of prostate cancer. With higher doses, concern exists that rectal injury may increase. This study analyzed the utility and limitations of the widely used Lyman-Kutcher- Burman (LKB) normal tissue complication probability model in projecting the hazards of rectal complication with high-dose RT. METHODS AND MATERIALS: A total of 128 patients were included in this study. These patients were treated with three-dimensional conformal RT alone at the University of Texas M.D. Anderson Cancer Center between 1992 and 1999. Patients were treated to 46 Gy with a four-field box technique followed by a six-field arrangement to boost the total dose to 78 Gy. All doses were delivered at 2 Gy/fraction to the isocenter. The minimal follow-up was 2 years. The end point for analysis was Grade 2 or worse rectal bleeding by 2 years. The LKB model was fitted to the data using the maximal likelihood method. RESULTS: Of the 128 patients, 29 experienced Grade 2 or worse rectal bleeding by 2 years. For the entire cohort, the parameters obtained from the fit of the LKB model were as follows: the volume factor was n = 3.91 (95% confidence interval [CI] 0.031 to infinity ), dose associated with 50% chance of complication for uniform whole rectal irradiation [TD50(1)] was 53.6 Gy (95% CI 50.0-75.1), and a determinant of the steepness of the dose-response curve, (m), was 0.156 (95% CI 0.036-0.271). A statistically significant difference was found in the rate of postradiation rectal bleeding in patients with hemorrhoids vs. those without hemorrhoids. The parameters obtained for the patients without hemorrhoids were as follows: n = 0.746 (95% CI 0.026 to infinity ), TD50(1) 56.7 Gy (95% CI 49.9-75.2), and m 0.092 (95% CI 0.019-0.189). CONCLUSION: Our analysis suggests a dose response for rectal bleeding probability along with a volume effect. We found that the LKB model might have limited utility in determining a large volume effect. We further suggest that LKB model should be used with caution in clinical practice.

Dose-Response Relationship, Radiation↗

PubMed2004

Telehealth practice recommendations for diabetic retinopathy.

Telehealth holds the promise of increased adherence to evidenced-based medicine and improved consistency of care. Goals for an ocular telehealth program include preserving vision, reducing vision loss, and providing better access to medicine. Establishing recommendations for an ocular telehealth program may improve clinical outcomes and promote informed and reasonable patient expectations. This document addresses current diabetic retinopathy telehealth clinical and administrative issues and provides recommendations for designing and implementing a diabetic retinopathy ocular telehealth care program. The recommendations also form the basis for evaluating diabetic retinopathy telehealth techniques and technologies. Recommendations in this document are based on careful reviews of current evidence, medical literature and clinical practice. They do not, however, replace sound medical judgment or traditional clinical decision-making. "Telehealth Practice Recommendations for Diabetic Retinopathy" will be annually reviewed and updated to reflect evolving technologies and clinical guidelines.

Diabetic Retinopathy↗

PubMed2003

Hazards of dose escalation in prostate cancer radiotherapy.

PURPOSE: To assess the benefit of escalating the dose in definitive prostate cancer radiotherapy vs. the associated risk of complications. MATERIALS AND METHODS: Between 1987 and 1999, 1087 patients with clinical Stage T1b-T3 adenocarcinoma of the prostate were definitively irradiated without hormonal therapy and had a pretreatment serum prostate-specific antigen (PSA) and Gleason score recorded. The median follow-up was 65 months. Doses ranged from 64 to 78 Gy, with the treatment techniques corresponding to the year of therapy and the prescribed dose. A total of 301 patients were treated on a randomized protocol to either 70 or 78 Gy. Also, 163 patients were treated with three-dimensional conformal therapy and had dose-volume histograms available for review. RESULTS: Tumor stage, grade, pretreatment PSA level, and radiation dose were all independent predictors of PSA disease-free survival (PSA-DFS) in multivariate analysis. The hazard rate for biochemical failure peaked at 1.5-3 years after radiotherapy. Although a statistically significant dose effect on PSA-DFS was found in the pretreatment PSA levels of those with both < or =10 ng/mL and >10 ng/mL, in those with a pretreatment PSA < or =10 ng/mL, the improvement in outcome was only seen going from a dose level of 64-66 Gy to 68-70 Gy with a 5-year PSA-DFS rate of 66% vs. 81% (p <0.0001). This was also confirmed by the data from the randomized patients who showed no difference in outcome whether treated to 70 Gy or 78 Gy. In patients with a pretreatment PSA level >10 ng/mL, a statistically significant improvement was found in disease-free outcome among the 64-66-Gy, 68-70-Gy, and 78-Gy levels. PSA-DFS was approximately 50% better at each higher dose level at 5 and 8 years after treatment. The dose had a statistically significant impact in both intermediate- and high-risk groups. Rectal morbidity was both dose and volume related. Although at 5 years after therapy, the Grade 2-3 rectal complication rate was twice as high for patients treated to 78 Gy than to 70 Gy, 26% vs. 12%, this risk could be markedly diminished by adhering to dose-volume constraints. CONCLUSIONS: In intermediate- and high-risk prostate cancer patients, although it appears that radiation-dose escalation may improve PSA-DF outcome, the price paid in treatment morbidity can be high without adequate attention to dose-volume constraints of normal tissue. Care must be taken to consider not only the hazard of tumor recurrence but also that of complications.

Adenocarcinoma↗

PubMed2003

A method for estimating duration of illness in Alzheimer's disease.

BACKGROUND: We developed a set of questions for generating an estimate regarding the date of first symptoms to the nearest half-year. Physicians then revised this estimate in conjunction with medical record review and patient/informant interviews, and by testing the estimate by recall of life events. One experienced examiner rated 36 patients, and each was independently rated by a second, less experienced rater. The physician ratings were compared to each other and to an unstructured caregiver estimate of duration using Lin concordance coefficients. There was excellent agreement between independent physician raters (rho = 0.95, p < 0.001). Caregiver estimates of duration were usually shorter because of failure to relate the first symptoms to the onset of disease.

Age of Onset↗

PubMed2003

Experience of ultrasound-based daily prostate localization.

PURPOSE: The NOMOS (Sewickley, PA) B-mode Acquisition and Targeting System (BAT) ultrasound system provides a rapid means of correcting for interfraction prostate positional variation. In this investigation, we report our experience on the clinical issues relevant to the daily use of the BAT system and the analysis of combined setup error and organ motion for 3509 BAT alignment procedures in 147 consecutive patients treated with IMRT for prostate cancer. METHODS AND MATERIALS: After setup to external skin marks, therapists performed the BAT ultrasound alignment procedure before each IMRT treatment. In this study, a single physician (A.C.) reviewed all BAT images and classified image quality and accuracy of image alignment by the therapist. On a scale of 1-3, near-perfect image quality or alignment was given a 1, fair image quality or misalignment > or = 5 mm (likely within the PTV) was given a 2, and unacceptable image quality or misalignment >5 mm (potential to violate the PTV) was given a value of 3. The distribution of shifts made was analyzed in each dimension and for all patients. The time required to perform the BAT alignment was also assessed in 17 patients. RESULTS: Among the 3509 attempted BAT procedures, the image quality was judged to be poor or unacceptable in 5.1% (181). Of the remaining 3328 BAT images, with quality scores of 1-2, alignments were unacceptable (>5 mm misalignment as judged by the reviewing physician) in 3% (100). The mean shift in each direction, averaged over all patients, was 0.5-0.7 mm. Interfraction standard deviation (1 SD) of prostate position based on combined setup error and internal organ motion is 4.9 mm, 4.4 mm, and 2.8 mm in the anteroposterior (AP), superior-inferior (SI), and lateral (RL) dimensions, respectively. The distribution of the shifts was a near-random Gaussian-type in all three major axes, with greater variations in AP and SI directions. The percent of BAT procedures in which the shift was >5 mm was 28.6% in AP, 23% in SI, and 9% in RL directions. The average BAT procedure took extra 5 min out of a 20-min time slot in a typical eight-field IMRT treatment. CONCLUSIONS: The quality of the daily ultrasound images was deemed acceptable in 95%. Major alignment errors by therapists were only 3%. The BAT system is clinically effective and feasible in a matter of 5 min. Although the accuracy of the BAT was not addressed in this investigation, we found a significant percentage of large shifts being made from the initial alignment position.

Humans↗

PubMed2003

Dosimetric predictors of xerostomia for head-and-neck cancer patients treated with the smart (simultaneous modulated accelerated radiation therapy) boost technique.

PURPOSE: To evaluate the predictors of xerostomia in the treatment of head-and-neck cancers treated with intensity-modulated radiation therapy (IMRT), using the simultaneous modulated accelerated radiation therapy (SMART) boost technique. Dosimetric parameters of the parotid glands are correlated to subjective salivary gland function. MATERIALS AND METHODS: Between January 1996 and June 2000, 30 patients with at least 6 months follow-up were evaluated for subjective xerostomia after being treated definitively for head-and-neck cancer with the SMART boost technique. Threshold limits for the ipsilateral and contralateral parotid glands were 35 Gy and 25 Gy, respectively. Dosimetric parameters to the parotid glands were evaluated. The median follow-up time was 38.5 months (mean 39.9 months). The results of the dosimetric parameters and questionnaire were statistically correlated. RESULTS: Xerostomia was assessed with a 10-question subjective salivary gland function questionnaire. The salivary gland function questionnaire (questions 1, 2, 3, 4, 6, and 9) correlated significantly with the dosimetric parameters (mean and maximum doses and volume and percent above tolerance) of the parotid glands. These questions related to overall comfort, eating, and abnormal taste. Questions related to thirst, difficulty with speech or sleep, and the need to carry water daily did not correlate statistically with the dosimetric parameters of the parotid glands. CONCLUSIONS: Questions regarding overall comfort, eating, and abnormal taste correlated significantly with the dosimetric parameters of the parotid glands. Questions related to thirst, difficulty with speech or sleep, and the need to carry water daily did not correlate statistically with the dosimetric parameters of the parotid glands. Dosimetric sparing of the parotid glands improved subjective xerostomia. IMRT in the treatment of head-and-neck cancer can be exploited to preserve the parotid glands and decrease xerostomia. This is feasible even with an accelerated treatment regimen like the SMART boost. More patients need to be evaluated using IMRT to identify relevant dosimetric parameters.

Adult↗

PubMed2003

Prostate adenocarcinoma presenting with inguinal lymphadenopathy.

The lymphatic spread of prostate adenocarcinoma most often involves the iliac, obturator, and hypogastric nodes. Inguinal lymphadenopathy is very rare during the early stages of this disease, especially in the absence of pelvic lymphadenopathy or other metastases. We present a case of prostate adenocarcinoma with inguinal node involvement during the initial presentation, emphasizing the importance of a complete physical examination and the consideration of other concurrent diseases.

Adenocarcinoma↗

PubMed2002

Classifying local disease recurrences after breast conservation therapy based on location and histology: new primary tumors have more favorable outcomes than true local disease recurrences.

BACKGROUND: To distinguish true local recurrences (TR) from new primary tumors (NP) and to assess whether this distinction has prognostic value in patients who develop ipsilateral breast tumor recurrences (IBTR) after breast-conserving surgery and radiotherapy. METHODS: Between 1970 and 1994, 1339 patients underwent breast-conserving surgery at The University of Texas M. D. Anderson Cancer Center for ductal carcinoma in situ or invasive carcinoma. Of these patients, 139 (10.4%) had an IBTR as the first site of failure. For the 126 patients with clinical data available for retrospective review, we classified the IBTR as a TR if it was located within 3 cm of the primary tumor bed and was of the same histologic subtype. All other IBTRs were designated NP. RESULTS: Of the 126 patients, 48 (38%) patients were classified as NP and 78 (62%) as TR. Mean time to disease recurrence was 7.3 years for NP versus 5.6 years for TR (P = 0.0669). The patients with NP had improved 10-year rates of overall survival (NP 77% vs. TR 46%, P = 0.0002), cause-specific survival (NP 83% vs. TR 49%, P = 0.0001), and distant disease-free survival (NP 77% vs. TR 26%, P < 0.0001). Patients with NP more often developed contralateral breast carcinoma (10-year rate: NP 29% vs. TR 8%, P = 0.0043), but were less likely to develop a second local recurrence after salvage treatment of the first IBTR (NP 2% vs. TR 18%, P = 0.008). CONCLUSIONS: Patients with NP had significantly better survival rates than those with TR, but were more likely to develop contralateral breast carcinoma. Distinguishing new breast carcinomas from local disease recurrences may have importance in therapeutic decisions and chemoprevention strategies. This is because patients with new carcinomas had significantly lower rates of metastasis than those with local disease recurrence, but were more likely to develop contralateral breast carcinomas.

Actuarial Analysis↗

PubMed2002

Prostate cancer radiation dose response: results of the M. D. Anderson phase III randomized trial.

PURPOSE: A randomized radiotherapy dose escalation trial was undertaken between 1993 and 1998 to compare the efficacy of 70 vs. 78 Gy in controlling prostate cancer. METHODS AND MATERIALS: A total of 305 Stage T1-T3 patients were entered into the trial and, of these, 301 with a median follow-up of 60 months, were assessable. Of the 301 patients, 150 were in the 70 Gy arm and 151 were in the 78 Gy arm. The primary end point was freedom from failure (FFF), including biochemical failure, which was defined as 3 rises in the prostate-specific antigen (PSA) level. Kaplan-Meier survival analyses were calculated from the completion of radiotherapy. The log-rank test was used to compare the groups. Cox proportional hazard regression analysis was used to examine the independence of study randomization in multivariate analysis. RESULTS: There was an even distribution of patients by randomization arm and stage, Gleason score, and pretreatment PSA level. The FFF rates for the 70- and 78 Gy arms at 6 years were 64% and 70%, respectively (p = 0.03). Dose escalation to 78 Gy preferentially benefited those with a pretreatment PSA >10 ng/mL; the FFF rate was 62% for the 78 Gy arm vs. 43% for those who received 70 Gy (p = 0.01). For patients with a pretreatment PSA 10 ng/mL who were treated to 78 Gy (98% vs. 88% at 6 years, p = 0.056). Rectal side effects were also significantly greater in the 78 Gy group. Grade 2 or higher toxicity rates at 6 years were 12% and 26% for the 70 Gy and 78 Gy arms, respectively (p = 0.001). Grade 2 or higher bladder complications were similar at 10%. For patients in the 78 Gy arm, Grade 2 or higher rectal toxicity correlated highly with the proportion of the rectum treated to >70 Gy. CONCLUSION: An increase of 8 Gy resulted in a highly significant improvement in FFF for patients at intermediate-to-high risk, although the rectal reactions were also increased. Dose escalation techniques that limit the rectal volume that receives >or=70 Gy to <25% should be used.

Aged↗

PubMed2002

Locoregional treatment outcomes for inoperable anthracycline-resistant breast cancer.

PURPOSE: To assess the therapeutic outcomes and treatment-related morbidity of patients treated with radiation for inoperable breast cancer resistant to anthracycline-containing primary chemotherapy. METHODS AND MATERIALS: We analyzed the medical records of breast cancer patients treated on five consecutive institutional trials who had been designated as having inoperable locoregional disease after completion of primary chemotherapy, without evidence of distant metastases at diagnosis. The cohort for this analysis was 38 (4.4%) of 867 patients enrolled in these trials. Kaplan-Meier statistics were used for survival analysis, and prognostic factors were compared using log-rank tests. The median follow-up of surviving patients was 6.1 years. RESULTS: Thirty-two (84%) of the 38 patients were able to undergo mastectomy after radiotherapy. For the whole group, the overall survival rate at 5 years was 46%, with a distant disease-free survival rate of 32%. The 5-year survival rate for patients who were inoperable because of primary disease extent was 64% compared with 30% for those who were inoperable because of nodal disease extent (p = 0.0266). The 5-year rate of locoregional control was 73% for the surgically treated patients and 64% for the overall group. Of the 32 who underwent mastectomy, the 5-year rate of significant postoperative complications was 53%, with 4 (13%) requiring subsequent hospitalization and additional surgical revision. Preoperative radiation doses of >or=54 Gy were significantly associated with the development of complications requiring surgical treatment (70% vs. 9% for doses <54 Gy, p = 0.0257). CONCLUSION: Despite the poorer prognosis of patients with inoperable disease after primary chemotherapy, almost one-half remained alive at 5 years and one-third were free of distant disease after multidisciplinary locoregional management. These patients have high rates of locoregional recurrence after preoperative radiotherapy and mastectomy, and the morbidity associated with this approach may limit dose-escalation strategies. Alternative therapeutic strategies such as novel systemic agents, use of planned myocutaneous repair for closure, or radiation combined with radiosensitizing agents, should be considered in this class of patients.

Adult↗

PubMed2002

Intrafraction prostate motion during IMRT for prostate cancer.

PURPOSE: Although the interfraction motion of the prostate has been previously studied through the use of fiducial markers, CT scans, and ultrasound-based systems, intrafraction motion is not well documented. In this report, the B-mode, Acquisition, and Targeting (BAT) ultrasound system was used to measure intrafraction prostate motion during 200 intensity-modulated radiotherapy (IMRT) sessions for prostate cancer. METHODS AND MATERIALS: Twenty men receiving treatment with IMRT for clinically localized prostate cancer were selected for the study. Pre- and posttreatment BAT ultrasound alignment images were collected immediately before and after IMRT on 10 treatment days for a total of 400 BAT alignment procedures. Any ultrasound shifts of the prostate borders in relation to the planning CT scan were recorded in 3 dimensions: right-left (RL), anteroposterior (AP), and superior-inferior (SI). Every ultrasound procedure was evaluated for image quality and alignment according to a 3-point grading scale. RESULTS: All the BAT images were judged to be of acceptable quality and alignment. The dominant directions of intrafraction prostate motion were anteriorly and superiorly. The mean magnitude of shifts (+/-SD) was 0.01 +/- 0.4 mm, 0.2 +/- 1.3 mm, and 0.1 +/- 1.0 mm in the left, anterior, and superior directions, respectively. The maximal range of motion occurred in the AP dimension, from 6.8 mm anteriorly to 4.6 mm posteriorly. The percentage of treatments during which prostate motion was judged to be 5 mm. The extent of intrafraction motion was much smaller than that of interfraction motion. Linear regression analysis showed very little correlation between the two types of motion (r = 0.014, 0.029, and 0.191, respectively) in the RL, AP, and SI directions. CONCLUSION: Using an ultrasound-based system, intrafraction prostate motion occurred predominantly in the anterior and superior directions, but was clinically insignificant. Intrafraction motion was much smaller than interfraction motion, and the two types of movement did not correlate.

Humans↗

PubMed2002

Intensity-modulated radiation therapy for pediatric medulloblastoma: early report on the reduction of ototoxicity.

PURPOSE: The combination of cisplatin chemotherapy and radiation therapy for the treatment of medulloblastoma has been shown to cause significant ototoxicity, impairing a child's cognitive function and quality of life. Our purpose is to determine whether the new conformal technique of intensity-modulated radiation therapy (IMRT) can achieve lower rates of hearing loss by decreasing the radiation dose delivered to the cochlea and eighth cranial nerve (auditory apparatus). PATIENTS AND METHODS: Twenty-six pediatric patients treated for medulloblastoma were retrospectively divided into two groups that received either conventional radiotherapy (Conventional-RT Group) or IMRT (IMRT Group). One hundred thirteen pure-tone audiograms were evaluated retrospectively, and hearing function was graded on a scale of 0 to 4 according to the Pediatric Oncology Group's toxicity criteria. Statistical analysis comparing the rates of ototoxicity was performed using Fisher's exact test with two-tailed analysis. RESULTS: When compared to conventional radiotherapy, IMRT delivered 68% of the radiation dose to the auditory apparatus (mean dose: 36.7 vs. 54.2 Gy). Audiometric evaluation showed that mean decibel hearing thresholds of the IMRT Group were lower at every frequency compared to those of the Conventional-RT Group, despite having higher cumulative doses of cisplatin. The overall incidence of ototoxicity was lower in the IMRT Group. Thirteen percent of the IMRT Group had Grade 3 or 4 hearing loss, compared to 64% of the Conventional-RT Group (p < 0.014). CONCLUSION: The conformal technique of IMRT delivered much lower doses of radiation to the auditory apparatus, while still delivering full doses to the desired target volume. Our findings suggest that, despite higher doses of cisplatin, and despite radiotherapy before cisplatin therapy, treatment with IMRT can achieve a lower rate of hearing loss.

Adolescent↗

PubMed2002

Recurrence of prostate adenocarcinoma presenting with multiple myeloma simulating skeletal metastases of prostate adenocarcinoma.

We present the case of a 77-year-old man with recurrence of prostate adenocarcinoma and widespread skeletal lesions. The skeletal lesions were found to be caused by multiple myeloma rather than metastatic spread of prostate adenocarcinoma. Various aspects of the radiographic imaging, evaluation of elevated prostate-specific antigen, and treatment of prostate adenocarcinoma are discussed.

Adenocarcinoma↗

PubMed2002

Gamma knife radiosurgery for treatment of trigeminal neuralgia in multiple sclerosis patients.

BACKGROUND: Trigeminal neuralgia is a paroxysmal pain syndrome commonly associated with multiple sclerosis. While gamma knife radiosurgery has been shown to be an effective treatment for most cases of trigeminal neuralgia, it is considered to be less efficacious in patients with multiple sclerosis and less viable as a treatment option. METHODS: Seven patients with multiple-sclerosis-associated trigeminal neuralgia were identified from 50 consecutive patients treated for trigeminal neuralgia at the Memorial-Hermann Gamma Knife Radiosurgery Center. A Leksell gamma knife was used to deliver 80 or 90 Gy to a single 4-mm isocenter targeting the fifth nerve root entry zone into the pons. The patients were followed for a median period of 28 months and graded on a scale of 1 to 5, adopted from the Barrow Neurological Institute. RESULTS: All 7 patients showed excellent responses to radiosurgery with complete resolution of their pain and cessation of pain medications. The time to maximal response varied from 1 day to 8 months after treatment. The only complication was persistent facial numbness over the distribution of V2 and V3 which occurred in 4 patients. One patient experienced a recurrence of pain (grade 3) 24 months after radiation treatment, and she is currently being treated with carbamazepine. CONCLUSIONS: Gamma knife radiosurgery is an effective treatment option for trigeminal neuralgia patients with multiple sclerosis. These patients should be informed that there appears to be a higher incidence of facial numbness and that a longer period of several months should be allowed before the full effects of treatment may be observed as compared to the general population.

Adult↗