So-Hyang Chung

Complications after gamma knife radiosurgery for benign meningiomas

Objectives: To analyse the results of gamma knife radiosurgery (GKS) for the trreatment of intracranial meningiomas and to assess possible factors related to the outcome and complications of such treatment. Methods: The authors retrospectively reviewed the clinical and radiological data of 179 patients (194 lesions) treated with GKS for meningiomas between May 1992 and October 2000. The mean follow up duration was 37.3 months (range 6.4 to 86.3 months). The study determined the correlation between radiosurgical outcome including imaging changes after GKS and multiple factors such as tumour location and size, patient characteristics, venous sinus status, pre-GKS degree of oedema, other treatment modalities, and radiosurgical parameters. Results: The radiological control rate was 97.1%. Magnetic resonance imaging (MRI) showed complications after GKS in 35 lesions (25.0%) among the 140 lesions followed up with MRI. Complications were divided into peritumorous imaging changes (33 lesions; 23.6%) and transient cranial nerve dysfunction (two lesions; 1.4%). Radiation induced imaging changes were seen mostly in convexity, parasagittal, and falx meningiomas that were deeply embedded in the cortex. About 60% of these were asymptomatic and the overall rate of symptomatic imaging changes was 9.3%. Neurological deficit related to imaging changes developed in only three patients, and all the symptoms were transient. Conclusion: GKS for intracranial meningiomas seems to be a safe and effective treatment. However, meningiomas of the convexity, parasagittal region, or falx cerebri have a higher incidence of peritumorous imaging changes after GKS than those of the skull base. Therefore, the use of GKS needs to be considered very cautiously in cerebral hemispheric meningiomas, taking into consideration patient age and general condition, tumour size and location, pattern of cortical embedding, relation between the tumour and venous sinuses, presenting symptoms, and patient preference.

Gamma Knife radiosurgery for functioning pituitary microadenoma.

Transsphenoidal microsurgery remains the treatment of choice for pituitary microadenomas One hundred and six patients were treated with Gamma Knife radiosurgery (GKRS) for pituitary adenomas, and of these, 23 patients (1 male, 22 female) had microadenomas. Twenty-two of these patients were followed up and endocrinological tests were available for 15 of these 22. Thirteen of these 15 had prolactinomas, while the remaining 2 had acromegaly. The follow-up period was from 3 to 26 months (median 12 months). The mean age was 33.6 years (range 21 to 60 years). The mean maximum tumor dose was 35.7 Gy and the mean margin dose was 22 Gy. Serum prolactin (PRL) was normalized in three patients, decreased in eight and unchanged in two. The growth hormone (GH) secretion in the acromegalic patients has remained unchanged through the follow-up period. Thus, GKRS is a valuable adjuvant to transsphenoidal microsurgery for patients with pituitary microadenomas.

Unilateral globus pallidus internus stimulation improves delayed onset post-traumatic cervical dystonia with an ipsilateral focal basal ganglia lesion

Treatment with unilateral left globus pallidus internus (GPi) deep brain stimulation is reported in a patient with severe delayed onset post-traumatic cervical dystonia. He had sustained severe head trauma at the age of 17 and had developed a mild right hemiparesis. Three years after the head injury, cervical dystonia with head turning to the left side developed. Magnetic resonance imaging (MRI) showed a discrete GPi lesion on the left side. At the age of 23, he underwent unilateral left GPi deep brain stimulation. He experienced immediate but short lasting benefit from the microlesioning effect of the electrode. With activation of deep brain stimulation, there was significant improvement of the cervical dystonia, persisting for 12 months of follow up. This case underlines the importance of the globus pallidus internus in the generation and amelioration of cervical dystonia.

Eye Mucosa: An Efficient Vaccine Delivery Route for Inducing Protective Immunity

The external part of the eye shares mucosa-associated common characteristics and is an obvious entry site for foreign Ags. We assessed the potential of eyedrop vaccination for effective delivery of vaccines against viral or bacterial infection in mice. Both OVA-specific IgG Ab in serum and IgA Ab in mucosal compartments were induced by eyedrops of OVA with cholera toxin (CT). Eyedrop vaccination of influenza A/PR/8 virus (H1N1) induced both influenza virus-specific systemic and mucosal Ab responses and protected mice completely against respiratory infection with influenza A/PR/8 virus. In addition, eyedrop vaccination of attenuated Salmonella vaccine strains induced LPS-specific Ab and complete protection against oral challenge of virulent Salmonella. Unlike with the intranasal route, eyedrop vaccinations did not redirect administered Ag into the CNS in the presence of CT. When mice were vaccinated by eyedrop, even after the occlusion of tear drainage from eye to nose, Ag-specific systemic IgG and mucosal IgA Abs could be induced effectively. Of note, eyedrops with OVA plus CT induced organogenesis of conjunctiva-associated lymphoid tissue and increased microfold cell-like cells on the conjunctiva-associated lymphoid tissue in the nictitating membrane on conjunctiva, the mucosal side of the external eye. On the basis of these findings, we propose that the eyedrop route is an alternative to mucosal routes for administering vaccines.

Treatment of spontaneous arterial dissections with stent placement for preservation of the parent artery.

SummaryBackground. A wide variety of treatment regimens have been advocated for dissections involving the intracranial arteries. Recently, the stent can be used to exclude the aneurysm from the circulation and preserve the parent artery. We evaluated the safety and efficacy of stent angioplasty for intracranial arterial dissections.Methods. Ten patients with spontaneous dissections, nine vertebral artery and one internal carotid artery lesions underwent endovascular treatment using stent placement as primary treatment modality. One stent placement was attempted in five patients initially. Three patients were intentionally treated with two overlapping stents which completely covered the aneurysm orifice. Two tandem stents were used in one patient to allow spanning the entire length of the dissection. Stent-assisted coil embolization was performed in one patient.Results. Of the 10 patients in whom stenting was tried, the overall success in reaching the target lesion with stents was 90%. Of the 9 patients treated with stents, stent release and positioning were considered optimal in 7 patients (77.8%) and suboptimal in two. Lesions of 8 patients were improved or stable in angiographic follow-up. However, one pseudo-aneurysm was enlarged, and subsequently, was treated by proximal occlusion using coils. There were no instances of postprocedural ischaemic attacks, new neurological deficits, and no new minor or major strokes prior to patient discharge. All parent arteries of the patient who underwent the successful procedure were preserved. On the modified Rankin scale used for the follow up, all patients were assessed as functionally improved or of stable clinical status.Conclusions. The success in reducing dissection-induced stenosis or pseudo-aneurysm, the patency rate obtained at follow-up, and the lack of strokes (ischaemic or haemorrhagic) suggest that stent placement offers a viable alternative to complex surgical procedures or deconstructive procedures. The long-term efficacy and durability of stent placement for arterial dissection remains to be determined in a large series.

Clinical application of a Scheimpflug system for lens density measurements in phacoemulsification

PURPOSE: To evaluate the relationship between lens density measured using the Pentacam Scheimpflug system and phacodynamics (phacoemulsification time, phacoemulsification energy, and balanced salt solution [BSS] use) in patients with age‐related nuclear cataract. SETTING: Department of Ophthalmology and Visual Science, Kangnam St. Marys Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea. METHODS: This prospective observer‐masked study was of eyes with age‐related nuclear cataract. Objective lens density (0 to 100 points) was determined using the Scheimpflug system. Subjective grading was by the Lens Opacities Classification System III (LOCS III). The correlations between lens density values and phacoemulsification time, phacoemulsification energy, and BSS use were analyzed prospectively. RESULTS: Fifty‐three patients (60 eyes) were evaluated. The mean Scheimpflug‐measured lens nuclear density was 14.71 ± 6.12 (SD). There was a positive linear correlation between the Scheimpflug‐measured lens nuclear density and the LOCS III grading scores for nuclear opalescence (NO) and nuclear color (NC) (r = 0.734 and 0.719, respectively; both P<.05). The Scheimpflug‐measured lens nuclear density correlated with torsional amplitude, time, and cumulated dissipated energy (CDE) (P<.05), but not with BSS use (P = .195). The CDE was more strongly correlated with Scheimpflug‐measured lens nuclear density (r = 0.797) than with LOCS III NO or NC scores (r = 0.614 and r = 0.637, respectively). CONCLUSIONS: Scheimpflug‐measured lens nuclear density correlated with phacoemulsification time and energy. The Scheimpflug system enabled quantitative cataract grading and may help predict phacodynamics in cataract surgery.

Comparison of higher-order aberrations after wavefront-guided laser in situ keratomileusis and laser-assisted subepithelial keratectomy

PURPOSE: To compare the higher‐order aberrations (HOAs) in 70 eyes (38 patients) that had wavefront‐guided laser in situ keratomileusis (LASIK) with those in 70 eyes (40 patients) that had wavefront‐guided laser‐assisted subepithelial keratectomy (LASEK) for the treatment of myopia. SETTING: Department of Ophthalmology, Yonsei University College of Medicine, Myongdong Bal‐geun sesang Eye Clinic, and Seran Eye Center, Seoul, Korea. METHODS: In a prospective study, 140 consecutive eyes of 78 patients were treated with wavefront‐guided LASIK or LASEK according to the patients choice after each procedure had been thoroughly explained. The patients were followed for 6 months. Best corrected visual acuity (BCVA), uncorrected visual acuity (UCVA), manifest refraction, and wavefront aberrations were measured at baseline and 1, 3, and 6 months after surgery. RESULTS: There were no significant differences in postoperative BCVA, UCVA, and manifest refraction between groups. The mean root‐mean‐square wavefront error of HOAs for a scotopic pupil in the wavefront‐guided LASIK group was significantly smaller than that in the wavefront‐guided LASEK group at 1 month. Analyzing individual Zernike coefficients, the spherical aberration and second coma were significantly smaller in the wavefront‐guided LASIK group than in the wavefront‐guided LASEK group at 1 month. This difference in HOAs between groups disappeared at 3 and 6 months. CONCLUSIONS: The HOAs in the scotopic condition were not different between the wavefront‐guided LASIK and LASEK groups beginning 3 months after surgery. However, the HOAs in the LASIK and LASEK groups had a different time course, especially in the case of spherical aberration. This finding suggests that postoperative changes in aberration contribute to the final outcome of wavefront‐guided ablation.

Microvascular decompression of the facial nerve for the treatment of hemifacial spasm: preoperative magnetic resonance imaging related to clinical outcomes.

Summary Background. The objective of this study was to investigate the role of preoperative three dimensional short-range magnetic resonance angiography (3D-TOF MRA) in predicting the clinical outcomes following microvascular decompression for the treatment of hemifacial spasm. Method. Preoperative magnetic resonance (MR) imaging was performed on all patients with hemifacial spasm (564 cases) between January 1992 and September 1998. Of the 564 patients, 440 patients were included in this retrospective study. The presence of vascular contact, offenders, and anomalies in the vertebro-basilar system, were determined by 3D-TOF MRA prior to microvascular decompression of the facial nerve. The preoperative findings were compared with the surgical findings and clinical outcomes. Findings. A correlation was found between the clinical outcome (p<0.01) and the presence of a vascular indentation at the root entry zone (REZ) of the facial nerve. A shift of the vertebrobasilar system to the symptomatic side was found in 214 (48.6%) patients with hemifacial spasm, compared to only 10 (13.5%) patients in the control group (p<0.01). The unilateral vertebral artery was observed in 43 (9.8%) patients with hemifacial spasm and in 8 (10.8%) of the control patients. A hypoplasia of the artery was found in 8 (1.8%) patients with hemifacial spasm and in 1 (1.4%) control patient. The compressing offenders in the patients, discovered by MRI in conjunction with MRA, were as follows: 45.9% (202 patients) in the anterior inferior cerebellar artery (AICA), 34.8% (153 patients) in the posterior inferior cerebellar artery (PICA), 12.5% (55 patients) in the vertebral artery (VA) and 6.8% (30 patients) in multiple vessels. In contrast to the compressing offenders seen on the MRA, the offenders confirmed during surgery were as follows: 43% (189 patients) in the AICA, 36.4% (160 patients) in the PICA, 1.4% (6 patients) in the VA, 19% (84 patients) in multiple vessels, and 0.2% (1 patient) in the vein. In our long-term follow-up series of the 440 patients with hemifacial spasm, an excellent surgical outcome was obtained in 86.3% of cases and a good outcome was achieved in 6.4% (mean follow-up duration, 45.5 months). Interpretation. Preoperative 3D-TOF MRA can identify the relationship between the facial nerve and adjacent vessels in patients with a hemifacial spasm and assist in preoperative planning. This study suggests that 3D-TOF MRA is useful for selecting appropriate patients for surgical treatment and, to some extent, as an additional role for predicting the clinical outcome.

Comparison of clinical efficacies of autologous serum eye drops in patients with primary and secondary Sjögren syndrome.

Purpose: Autologous serum eye drops are considered to be safe and efficient for the treatment of dry eyes associated with Sjögren syndrome (SS). The purpose of this study was to compare the clinical efficacies of autologous serum eye drops in the management of primary and secondary SS. Methods: Patients with primary (n = 20; 35 eyes) and secondary (n = 14; 27 eyes) SS dry eye were included. Serum concentrations of proinflammatory cytokines [tumor necrosis factor &agr;, interleukin (IL)-1&bgr;, IL-6, and IL-8] were measured by a multiplex immunobead assay. The ocular symptom scores, ocular staining grades, and tear break-up time were evaluated before and after 4 weeks of 50% autologous serum eye drop application. Results: At enrollment, patients with secondary SS had higher serum proinflammatory cytokine levels (tumor necrosis factor &agr;, IL-1&bgr;, IL-6, and IL-8) than patients with primary SS (P < 0.01). After 4 weeks of autologous serum eye drop treatment, patients with primary SS had significantly improved ocular symptoms (P < 0.01), ocular surface staining grades (P < 0.01), and tear break-up time (P < 0.05). However, patients with secondary SS had no improvement (P > 0.05). Conclusions: Our results suggest that autologous serum eye drops might not be effective for the treatment of secondary SS because of elevated serum proinflammatory cytokine levels.

Mycobacterium abscessus Keratitis after LASIK with IntraLase® Femtosecond Laser

A healthy 38-year-old woman developed 2 white spots in her left eye 2 weeks after bilateral laser in situ keratomileusis (LASIK) using the IntraLase® femtosecond laser. Initial treatment included levofloxacin 0.5% but was unsuccessful. The surgeon irrigated the interface and repositioned the flap due to a worsened lesion. She was referred to us after the keratitis had not improved. The flap was lifted for collection of the specimen and irrigation of the interface. The keratitis was treated with intensive topical clarithromycin 1%, amikacin 1.25% and oral clarithromycin, which improved her clinical condition. She developed a toxic reaction to amikacin 1.25%, which was replaced by moxifloxacin 0.5%. Mycobacterium abscessus was identified. The keratitis resolved over 2 months. Five months after treatment, the patient had a visual acuity of 20/20 with correction. Nontuberculous mycobacteria should be considered as an etiologic agent, even in cases of infectious keratitis after LASIK using the femtosecond laser.