Proton magnetic resonance spectroscopy in mild cognitive impairment and Alzheimer's disease: a preliminary study.

BACKGROUND: Mild cognitive impairment (MCI) is recognized as a transitional clinical state between normal aging and Alzheimer's disease (AD) and has significant higher rate of progression to AD. OBJECTIVE: To compare the changes of metabolites between AD and MCI in specific locations of the brain by using Magnetic Resonance Spectroscopy (MRS). MATERIAL AND METHOD: MMSE-Thai 2002 and neuropsychological test were performed in 17 patients with memory problem, classified into AD and MCI (10, 7 patients respectively). All patients and three age-matched cognitively normal volunteers were examined with conventional MRI and MRS of the brain. Volumes of interest were located at both-sided frontal and parietal deep white matter. NAA/Cr, Cho/Cr and mI/Cr ratios of the patients were analyzed and statistically evaluated relative to cognitively normal volunteers. Statistical analysis was performed using Cohen's kappa coefficient and Kruskal-Wallis test. RESULTS: There was no statistically significant change in metabolites in all brain regions. For AD relative to cognitively normal volunteers, there were strong tendency toward statistically significant decreased NAA/Cr at the left frontal and left parietal regions (p = 0.043 each) and decreased Cho/Cr at the left frontal region (p = 0.028). CONCLUSION: The changes of the metabolite ratios of MCI were much closer to AD. Strong tendency toward statistically significant decreased NAA/Cr in the left cerebral hemisphere, predominantly parietal region and strong tendency toward statistically significant decreased Cho/Cr at the left frontal region were indicative of neurodegeneration and replacement by gliosis. MRS may be useful for predict a chance that cognitively normal people may convert to the AD.

CT perfusion in predicting treatment response of nasopharyngeal carcinoma.

BACKGROUND: Direct nasopharyngoscope with biopsy is the gold standard for assessing tumor response of nasopharyngeal carcinoma (NPC). It is invasive with risk of hemorrhage or infection. OBJECTIVE: Explore the usefulness of pre-treatment CTperfusion (CTP) and clarify the parameters in predicting the treatment response. MATERIAL AND METHOD: Twelve patients with histologically proven NPC who underwent pretreatment contrast enhanced CT (CECT) and CTP with parameters (blood flow (BF), blood volume (BV) and permeability), followed by CECT at three months after complete concurrent chemo-radiotherapy or radiotherapy were included in this prospective, cross-sectional study. Pre- and post-treatment primary tumor volumes based on free hand drawn region encompassing the entire primary tumor were measured and compared The response to therapy was also assessed by RECIST guideline version 1.1, based on sum of the diameters of longest diameter for primary tumor and minimal transverse diameter for nodal lesions for all target lesions on the pre- and post-treatment imaging, and classified into "Non-response" group and "Complete response" group. Statistical analysis was performed using Pearson 's correlation coefficients and Mann-Whitney U test. RESULTS: Ten and two patients (83.3%, 16.7%) belonged to "Complete response" and "Non-response "groups respectively. Elevated permeability, BF and BV had a following trend of positive correlation with degree of primary tumor volume reduction without statistical significance. The values ofpermeability, BFE and BV had a trend to be higher in "Complete response" group compared with "Non-response" group (p = 0.053, 0.390 and 0.519 respectively). The permeability had the highest predictive value with an area under the ROC curve of 0.95 and cutoff value of 45 ml/100 g/min (sensitivity, 100%; specificity, 90%). CONCLUSION: Pre-treatment CTP can be useful non-invasive tool in predicting treatment response of NPC. Permeability is the excellent parameter used to differentiate between complete and non-response groups.

Identification of stroke mimics among clinically diagnosed acute strokes.

BACKGROUND: Stroke is a clinically syndrome of a sudden onset of neurological deficit in a vascular cause. Stroke mimics is the non-vascular disorders with stroke-like clinical symptoms. It is important to distinguish true stroke from mimics since treatment plan may differ OBJECTIVE: To determine the incidence of the stroke mimics and identify their etiologies. MATERIAL AND METHOD: All non-contrast head CT of the patients with clinically diagnosed stroke who immediately received imaging upon arrival at the emergency department of the university hospital were retrospectively reviewed in 12-month period between January 1 and December 31, 2008. Medical records, laboratory results, MRI, and 6-month clinical follow-up records were reviewed for final diagnosis. RESULTS: Seven hundred four patients were included in this study, including 363 (51.5%) men and 341 (48.5%) women with range in age from 24 to 108 years. Amongst those, 417 (59.2%) were ischemic stroke, 80 (11.40%) were hemorrhagic stroke, 186 (26.4%) were stroke-mimics, and 21 (3%) were inconclusive. The etiologies among stroke-mimics were metabolic/intoxication (35, 18.8%), sepsis (28, 15.0%), seizure (21, 11.3%), syncope (20, 10.8%), subdural hemorrhage (14, 7.5%), vertigo (11, 6.0%), brain tumor (10, 5.30%), central nervous system infection (5, 2.7%), others (26, 14.0%), and unspecified (16, 8.6%). CONCLUSION: Incidence rates and etiologies of the stroke mimics were similar to the western reports. However the frequency of each mimic was not.

Apparent diffusion coefficients in evaluation of pediatric brain tumors.

BACKGROUND: MRI, which has high sensitivity in brain tumor detection, cannot reliably determine tumor grading or histology. Diffusion-weighted imaging and apparent diffusion coefficients (ADCs) provide information of tumor cellularity that can correlate with grading. OBJECTIVE: To investigate ADCs in differentiation low-grade from high-grade pediatric brain tumors. MATERIAL AND METHOD: Preoperative MRI, DWI, and ADC images of pediatric patients with pathologically proven brain tumors were retrospectively reviewed at a university hospital in two-year periods and classified into low-grade and high-grade categories. Regions of interest were placed manually at the center and periphery of the solid tumor regions, then ADC values were calculated at "b" values = 0, 1000 sec/mm2. RESULTS: The ADC values were calculated in 15 patients, which included 12 males and three females with an age range from three to 14 years. Seven and eight were with low- and high-grade tumors respectively. The ADC values of low-grade tumors were markedly higher than those of high-grade tumors with statistically significant differences by all methods of measurements at the central peripheral, and average areas on Man-Whitney U test, with p-values of 0.037, 0.009, and 0.021, respectively. CONCLUSION: MRI with ADCs for preoperative pediatric tumor evaluation may be useful for predicting tendency of tumor grading and surgical planning.

Antiphospholid antibody syndrome and Hb E/Beta thalassemia disease post-allogeneic stem cell transplantation.

We report a 10-year-old male with Hb E/Beta thalassemia disease who developed chronic graft-versus-host disease (cGVHD) of antiphospholipid antibody syndrome after successful allogeneic stem cell transplantation (SCT). He exhibited a recurrent ischemic stroke on day 368 post-SCT while on cyclosporine A, azathioprine, and prednisolone. The immunosuppressive agents were switched to pulse methylprednisolone, tacolimus, mycophenolate mofetil, and enoxaparin, but the patient was more confused. An additional plasma exchange which was aimed at the immediate removal of autoantibody was performed with a good response. The symptoms rapidly disappeared except for the complex partial seizure which persisted until seven years post-SCT.

Plasticity of the motor cortex in patients with brain tumors and arteriovenous malformations: a functional MR study.

OBJECTIVE: Test the hypothesis about the potential role of functional MRI (fMRI) to evaluate the plasticity of the cortical motor areas in patients with brains tumors and brain arteriovenous malformations (AVMs) and measurement of the lesion-to-fMRI activation distance for predicting risk of new motor deficit after surgery. MATERIAL AND METHOD: This was a retrospective study. The present study population enrolled eight patients with motor cortex lesions. Cortical motor representations were mapped in these patients harboring tumor or AVMs occupying the region of primary motor cortex (M1). Five patients had known diagnosis of primary brain tumor including glioblastoma multiforme, (n = 1), diffuse astrocytoma (n = 2), dysembryoplastic neuroepithelial tumor (DNET) (n = 1) and unknown pathology (n = 1). Three patients had known diagnosis of brain AVMs. Three patients showed hemiparesis at the time of presentation. Focal/generalized seizure or headache was present in the remaining patients. Simple movements of both hands were performed Localization of the activation in the affected hemisphere was compared with that in the unaffected hemisphere and evaluated with respect to the normal M1 somatotopic organization. Distance between the location of the fMRI activation (M1) and margin of the lesion was recorded. RESULTS: Cortical activation was found in two patterns: 1) functional displacement within affected M1 independent of the structural distortion induced by the tumor or AVMs (n = 7) and 2) presence of activation within the non-primary motor cortex without activation in the affected or unaffected M1 (n = 1). CONCLUSION: Brain tumor or AVMs led to reorganization within the somatotopic affected M1 and can expand into non-primary motor cortex area. Distortion of the anatomy alone by the space-taking lesion did not influence the location of the reorganized cortex. No particular type of reorganization pattern could be predicted fMRI could be localized reorganized cortex and was found to be a useful tool to assess the lesion-to-activation distance for predicting risk of new motor deficit after surgery. The present study thus emphasizes the importance of considering additional fMRI with structural MRI to evaluate individual differences in cortical plasticity for treatment planning, particularly in the neurosurgical procedure.

Concurrent radiotherapy with temozolomide followed by adjuvant temozolomide and cis-retinoic acid in children with diffuse intrinsic pontine glioma.

The prognosis of children with diffuse intrinsic pontine glioma (DIPG) is very poor. Radiotherapy remains the standard treatment for these patients, but the median survival time is only 9 months. Currently, the use of concurrent radiotherapy with temozolomide (TMZ) has become the standard care for adult patients with malignant gliomas. We therefore investigated this approach in 12 children diagnosed with DIPG. The treatment protocol consisted of concurrent radiotherapy at a dose of 55.8-59.4 Gy at the tumor site with TMZ (75 mg/m(2)/day) for 6 weeks followed by TMZ (200 mg/m(2)/day) for 5 days with cis-retinoic acid (100 mg/m(2)/day) for 21 days with a 28-day cycle after concurrent radiotherapy. Ten of the 12 patients had a clinical response after the completion of concurrent radiotherapy. Seven patients had a partial response, four had stable disease, and one had progressive disease. At the time of the report, 9 of the 12 patients had died of tumor progression, one patient was alive with tumor progression, and two patients were alive with continuous partial response and clinical improvement. The median time to progression was 10.2 +/- 3.0 months (95% confidence interval [CI], 4.2-16.1 months). One-year progression-free survival was 41.7% +/- 14.2%. The median survival time was 13.5 +/- 3.6 months (95% CI, 6.4-20.5 months). One-year overall survival was 58% +/- 14.2%. The patients who had a partial response after completion of concurrent radiotherapy had a longer survival time (p = 0.036) than did the other patients (those with stable or progressive disease). We conclude that the regimen of concurrent radiotherapy and TMZ should be considered for further investigation in a larger series of patients.

Favorable response of intraommaya topotecan for leptomeningeal metastasis of neuroblastoma after intravenous route failure.

A 3-year-old male, diagnosed with stage 4 neuroblastoma, developed recurrent leptomeningeal metastasis after multi-modality treatment including multi-agent chemotherapy, surgery, high dose chemotherapy plus stem cell rescue, cis-retinoic acid and intravenous (IV) topotecan. He then received intraommaya (IO) topotecan three times weekly (maximum dose; 0.4 mg). A complete response was achieved by a resolution of malignant cells in cerebrospinal fluid and resolution leptomeningeal enhancement by brain MRI. Treatment toxicities included low-grade fever and minimal headache. The duration of treatment response from IO topotecan was 18 weeks. The survival time from CNS recurrence in this patient was 13 months. We suggest IO topotecan be considered for neoplastic meningitis of tumors with known sensitivity to topotecan.

Lacrimal myoepithelial carcinoma ex recurrent pleomorphic adenoma: A clinicopathological report and review of the literature.

Myoepithelial carcinoma is an uncommon malignant tumor of the lacrimal gland, composed of neoplastic myoepithelial cells with an infiltrative growth. The present study describes a unique case of progressive proptosis and blindness of the right eye in a 68-year-old woman following total tumor removal for lacrimal pleomorphic adenoma. Clinical study, surgical exploration, and pathology revealed lacrimal myoepithelial carcinoma ex recurrent pleomorphic adenoma, T2N0M0. In addition, 18 cases of lacrimal myoepithelial tumor that have been previously described in the literature are reviewed. The application of clinical, radiological, histopathologic, and immunohistochemical investigations may help to reach the definite diagnosis. Criteria for malignancy of lacrimal myoepithelial tumor should be the same as salivary myoepithelial tumor diagnosis, until long-term outcome data for a larger number of patients with lacrimal myoepithelial carcinoma become available.

Giant cell reparative granuloma concurrent with squamous cell carcinoma of the temporal bone: a case report and review of the literature.

A case of giant cell reparative granuloma concurrent with squamous cell carcinoma of the right temporal bone in a 44-year-old man with clinically presenting otorrhea from the mass of the right acoustic canal with hearing loss is reported. The histopathological examination of the lesion characterizes by multinucleated giant cells with in a fibroblastic stroma and area of keratinizing squamous cell carcinoma. GCRG may have been a local reaction provoked by the squamous cell carcinoma. Clinical and pathological features with briefly reviewed relevant literatures of temporal GCRG describing 24 cases are discussed. The patients have the mean age of 34.8 years. The ages of the patients ranged from 4 months to 72 years old. Temporal bone GCRG shows a male predilection of approximately 3:1. The frequently presenting symptoms of temporal bone GCRG are hearing loss, mass, tinnitus, otalgia, otorrhea, vertigo, headache, facial weakness, and diplopia. This is the first reported description in the literature of temporal bone GCRG concurrent with squamous cell carcinoma.

Stereotactic radiation therapy for optic nerve sheath meningioma; an experience at Ramathibodi Hospital.

OBJECTIVE: To evaluate results of stereotactic radiotherapy for the treatment of optic nerve sheath meningioma (OM) at Ramathibodi Hospital. MATERIAL AND METHOD: Twelve patients with primary OM were treated with stereotactic radiation between 1998 and 2005. Five patients underwent surgery and had no light perception before radiation. All patients except one were treated with fractionated stereotactic radiotherapy (FSRT). Mean average dose of FSRT was 55. 7 Gy; 180 cGy/fraction. One patient was treated with 15-Gy stereotactic radiosurgery. RESULTS: With a median follow-up of 34 months, there was no visual improvement in the five patients who were completely blind before radiation. Visual acuity improved in four patients and remained stable in two patients. Four of six patients had improved visual field, and five of six decreased in proptosis. Follow-up images were available in six patients, showing minimal tumor regression in five and stable in one. No serious acute side effect was observed. Vision became worse in one patient, who developed vitreous hemorrhage two years after FSRT. CONCLUSION: Stereotactic radiotherapy is an effective treatment for primary OM. It provides tumor control and visual preservation with low risk of complications. However more patients and further follow-up are needed for long-term outcomes.

Polymorphous low-grade adenocarcinoma of the epiglottis: A case report.

Polymorphous low-grade adenocarcinoma is an uncommon malignant tumor derived from the terminal duct cells of the salivary glands. The present study described a rare case of polymorphous low-grade adenocarcinoma, T2N0M0 stage 2, in a 65-year-old man, who presented with a sore throat and painful dysphagia. Computed tomography revealed an infiltrative heterogenous enhancing mass involving the left aryepiglottic fold. He underwent a tumor removal with frozen section for evaluating the surgical margin. Subsequent supraglottic laryngectomy was performed. Polymorphous low-grade adenocarcinoma was diagnosed histologically, characterized by cytologic uniformly, morphologic diversity and an infiltrative growth pattern. Epiglottic cartilaginous invasion by the tumor is demonstrated. Clinical, radiological, endoscopic and pathological features with briefly reviewed relevant literatures are discussed. This is the first reported description in the literature, to the best of our knowledge, of an epiglottic polymorphous low-grade adenocarcinoma receiving successful supraglottic laryngectomy with 7 year disease free survival.

Evaluation of MR cisternography in diagnosis of cerebrospinal fluid fistula.

PURPOSE: To study the clinical usefulness and sensitivity of MR cisternography as noninvasive study in the diagnosis of CSF fistula in patients with clinical diagnosis CSF rhinorrhea or otorrhea. METHOD: Thirty-five patients with clinically diagnosed CSF leakage were examined for site of dural tear with MR cisternography with additional plain high-resolution CT in some cases from Jan. 1999 to Dec.2002. The MR imaging technique was performed as a heavily T2 weighted fast spin echo study with fat suppression in axial, coronal and sagittal projections. Criteria for positive results were demonstrable fistular tract connecting subarachnoid space to paranasal sinus/petrous bone, and/or dural discontinuity, and/or bone defect with pneumocephalus, and/or presence of brain herniation. Eighteen of the patients subsequently had exploratory surgery for fistula. Sensitivity analysis of the surgical results was compared with the findings at MR cisternography. RESULT: MR cisternography showed significant correlation with surgical findings with sensitivity of 89%. Additional high resolution CT were complete agreement with site of fistular tract. The pathogenesis of CSF leakage was related to trauma (86%). The commonly found dural/bony defect and location of connecting fislular tract were cribriform plate and ethmoid sinus of 58%, 55% respectively. CONCLUSION: In the presence of clinically diagnosed CSF leakage, the combination of MR cisternography and plain high-resolution CT are highly accurate in locating the site and extent of CSF fistula and should be considered a viable noninvasive alternative to CT cisternography and Tc-99m-DTPA cisternography.

Nasopharyngeal carcinoma segmentation using a region growing technique.

PURPOSE: This paper proposes a new image segmentation technique for identifying nasopharyngeal tumor regions in CT images. The technique is modified from the seeded region growing (SRG) approach that is simple but sensitive to image intensity of the initial seed. METHODS: CT images of patients with nasopharyngeal carcinoma (NPC) were collected from Ramathibodi hospital, Thailand. Tumor regions in the images were separately drawn by three experienced radiologists. The images are used as standard ground truth for performance evaluation. From the ground truth images, common sites of nasopharyngeal tumor regions are different from head to neck. Before the segmentation, each CT image is localized: above supraorbital foramen (Group I), below oropharynx (Group III), or between these parts (Group II). Representatives of the CT images in each part are separately generated based on the Self-Organizing Map (SOM) technique. The representative images contain invariant features of similar NPC images. For a given CT slice, a possible tumor region can be approximately determined from the best matching representative image. Mode intensity within this region is identified and used in the SRG technique. RESULTS: From 6,606 CT images of 31 NPC patients, 578 images contained the tumors. Because NPC images above the supraorbital foremen were insufficient for study (6 images from 1 subject), they were excluded from the analysis. The CT images with inconsistent standard ground truth images, metastasis cases, and bone invasion were also disregarded. Finally, 245 CT images were taken into account. The segmented results showed that the proposed technique was efficient for nasopharyngeal tumor region identification. For two seed generation, average corresponding ratios (CRs) were 0.67 and 0.69 for Group II and Group III, correspondingly. Average PMs were 78.17 and 82.47%, respectively. The results were compared with that of the traditional SRG approach. The segmentation performances of the proposed technique were obviously superior to the other one. This is because possible tumor regions are accurately determined. Mode intensity, which is used in place of the seed pixel intensity, is less sensitive to the initial seed location. Searching nearby tumor pixels is more efficient than the traditional technique. CONCLUSION: A modified SRG technique based on the SOM approach is presented in this paper. Initially, a possible tumor region in a CT image of interest is approximately localized. Mode intensity within this region is determined and used in place of the seed pixel intensity. The tumor region is then searched and subsequently grown. The experimental results showed that the proposed technique is efficient and superior to the traditional SRG approach.

Acute Marchiafava-Bignami disease with callosal, cortical, and white matter involvement.

Marchiafava-Bignami disease (MBD) is a rare complication of chronic alcoholism whose main pathology is symmetrical demyelination and necrosis of the corpus callous. The lesion may be found in hemispheric white matter, but the cortical involvement is extremely rare. We reported herein two cases of MBD with magnetic resonance (MR) findings, additional MR spectroscopy, and MR perfusion which revealed acute demyelination at the corpus callosum and symmetrical signal abnormality at cortical gray matter and hemispheric white matter.