Early Diagnosis of Aseptic Meningitis in Ramsay Hunt Syndrome on 10-Minute Delayed CE 3D FLAIR Image: a Case Report

Ramsay Hunt syndrome (RHS) is a disease caused by varicella-zoster virus (VZV) infection that can be diagnosed through clinical symptoms with or without imaging evaluations. The typical features of RHS on imaging evaluation include signal changes and enhancement in the internal auditory canal (IAC) nerves, and the labyrinthine segment of cranial nerve VII (CN VII) and cranial nerve VIII (CN VIII). In some patients, inner ear structure (cochlear and vestibular apparatus) is involved in RHS. Neurologic complications, such as encephalitis and meningitis, are rare in RHS, but are known to occur. Therefore, magnetic resonance imaging (MRI) is necessary to detect both abnormal signal intensity in the IAC, CN VII, CN VIII, inner and ear structure, and CNS complications. We report an RHS patient with CN VII, VIII, and leptomeningeal enhancement within the cerebellar folia on 10-min delayed, contrast-enhanced (CE), three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) imaging.

Early Diagnosis of Aseptic Meningitis in Ramsay Hunt Syndrome on 10-Minute Delayed CE 3D FLAIR Image: a Case Report

Ramsay Hunt syndrome (RHS) is a disease caused by varicella-zoster virus (VZV) infection that can be diagnosed through clinical symptoms with or without imaging evaluations. The typical features of RHS on imaging evaluation include signal changes and enhancement in the internal auditory canal (IAC) nerves, and the labyrinthine segment of cranial nerve VII (CN VII) and cranial nerve VIII (CN VIII). In some patients, inner ear structure (cochlear and vestibular apparatus) is involved in RHS. Neurologic complications, such as encephalitis and meningitis, are rare in RHS, but are known to occur. Therefore, magnetic resonance imaging (MRI) is necessary to detect both abnormal signal intensity in the IAC, CN VII, CN VIII, inner and ear structure, and CNS complications. We report an RHS patient with CN VII, VIII, and leptomeningeal enhancement within the cerebellar folia on 10-min delayed, contrast-enhanced (CE), three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) imaging.

Primary Central Nervous System Involvement in Peripheral T-Cell Lymphoma:A Case Report

Primary central nervous system T-cell lymphoma (PCNSTL) is an extremely rare type of brain tumor. There are only few reports on the imaging findings of patients with PCNSTL. Herein, we report the imaging findings of a patient with peripheral T-cell lymphoma-not otherwise specified that presented with numerous small nodular and patchy strongly enhancing lesions on MRI.

Transient Splenial Lesions in the Splenium of Corpus Callosum in Seven Patients: MR Findings and Clinical Correlations

PURPOSE: The purpose of this study is to correlate the imaging findings and the clinical findings in patients with transient splenial lesions (TSL). MATERIALS AND METHODS: Total of 7 patients (M: F = 4: 3; age range 11 - 38 years, mean age 25.5 years) were studied between November 2006 and April 2011. The MRI findings and clinical findings in all patients were retrospectively reviewed. The location, MR signal intensity, restricted diffusion, enhancement pattern and reversibility from the follow up images were reviewed. Clinical features were reviewed with respect to the presented symptoms, signs, treatment and outcome. RESULTS: The lesions were located in the splenium of corpus callosum in all patients. All lesions showed high signal intensity on diffusion weighted imaging (DWI), and six patients showed restricted diffusion on the apparent diffusion coefficient (ADC) map. ADC map was not available in one patient. All lesions (n = 7) showed high signal intensity on the T2 weighted image (T2WI). Five of the patients (71.4%) with follow up images (range 7 - 34 days) showed complete resolution of focal high signal intensity on DWI, with recovery of ADC values as well as T2WI. After contrast media administration, none of the lesions showed any enhancements. All lesions with various etiologies including TB medication were developed in younger age patients and showed reversibility after the acceptable period of minimum 7 days with conservative treatment. CONCLUSION: All TSL showed nonspecific imaging findings, including restricted diffusion on DWI and ADC map on the initial images. However, reversibility of the lesions and the young age preference can be a characteristic finding of TSL with acceptable period of minimum 7 days. In addition, to keep it in mind that various etiologies including TB medication may cause TSL, is important for radiologists as well as clinicians.

Diffusion MR Imaging of Postoperative Bilateral Acute Ischemic Optic Neuropathy

A 57-year-old woman experienced bilateral acute ischemic optic neuropathy after spine surgery. Routine MR imaging sequence, T2-weighted image, showed subtle high signal intensity on bilateral optic nerves. A contrast-enhanced T1 weighted image showed enhancement along the bilateral optic nerve sheath. Moreover, diffusion-weighted image (DWI) and an apparent diffusion coefficient map showed markedly restricted diffusion on bilateral optic nerves. Although MR findings of T2-weighted and contrast enhanced T1-weighted images may be nonspecific, the DWI finding of cytotoxic edema of bilateral optic nerves will be helpful for the diagnosis of acute ischemic optic neuropathy after spine surgery.

Gene Expression Profiles in Genetically Different Mice Infected with Toxoplasma gondii: ALDH1A2, BEX2, EGR2, CCL3 and PLAU

Toxoplasma gondii can modulate host cell gene expression; however, determining gene expression levels in intermediate hosts after T. gondii infection is not known much. We selected 5 genes (ALDH1A2, BEX2, CCL3, EGR2 and PLAU) and compared the mRNA expression levels in the spleen, liver, lung and small intestine of genetically different mice infected with T. gondii. ALDH1A2 mRNA expressions of both mouse strains were markedly increased at day 1-4 postinfection (PI) and then decreased, and its expressions in the spleen and lung were significantly higher in C57BL/6 mice than those of BALB/c mice. BEX2 and CCR3 mRNA expressions of both mouse strains were significantly increased from day 7 PI and peaked at day 15-30 PI (P<0.05), especially high in the spleen liver or small intestine of C57BL/6 mice. EGR2 and PLAU mRNA expressions of both mouse strains were significantly increased after infection, especially high in the spleen and liver. However, their expression patterns were varied depending on the tissue and mouse strain. Taken together, T. gondii-susceptible C57BL/6 mice expressed higher levels of these 5 genes than did T. gondii-resistant BALB/c mice, particularly in the spleen and liver. And ALDH1A2 and PLAU expressions were increased acutely, whereas BEX2, CCL3 and EGR2 expressions were increased lately. Thus, these demonstrate that host genetic factors exert a strong impact on the expression of these 5 genes and their expression patterns were varied depending on the gene or tissue.

Lymphocytic Hypophysitis with Diabetes Insipidus: Improvement by Methylprednisolone Pulse Therapy

Lymphocytic hypophysitis is a rare inflammatory disorder in the pituitary gland. The lesion is usually confined to the adenohypophysis. Although the involvement of the posterior pituitary gland or the stalk is rare, such patients with diabetes insipidus have been reported. Surgery has been used to make the definitive diagnosis. Recent studies suggest, however, that the pathologic diagnosis may not be necessary always. We reported a case of Lymphocytic hypophysitis managed by methylprednisolone pulse therapy. A 50-year-old premenopausal woman with Lymphocytic hypophysitis and diabetes insipidus was treated with methylprednisolone pulse therapy. Her adenopituitary lesion disappeared and the diabetes insipidus resolved. The optimal management for patients with lymphocytic hypophysitis may be the high index of the suspicion prior to the extensive surgical resection. In addition, methylprednisolone pulse therapy may improve the clinical and MRI findings.

Spontaneous Cerebral Microbleeds on Gradient Echo MR Imaging in the Stroke Patients

PURPOSE: To investigate the spontaneous cerebral microbleeding occurring at gradient-echo MRI, and its relationship with associated stroke lesions and risk factors. MATERIALS AND METHODS: Between September 2001 and December, 2002, 32 patients (21 men and 11 women; mean age 63 years) in whom cerebral microbleeding occurred at gradient-echo MRI were retrospectively investigated. Using a 1.5 T MR imager, spin-echo T1-weighted, fast spin-echo T2-weighted, diffusion-weighted, and gradient-echo images were obtained. The number and location of microbleeds seen on gradient echo images, patient data, and associated stroke lesions such as intracerebral hemorrhage and lacunar and territorial infarction were assessed. RESULTS: Among the 32 patients, 563 microbleeds and between 1 and 66 (mean, 17.6) were noted at gradientecho imaging. Microbleeding occurred in the cortical/subcortical area (n=216), the basal ganglia (n=173), thalamus (n=92), cerebellum (n=41), brainstem (n=36) and corpus callosum (n=1), and in 20 patients was bilateral. Patients had a history of hypertension (n=26), hypertriglycemia (n=12), heart disease (n=4), and diabetes mellitus (n=3). Stroke lesions were seen in 27 patients, intracerebral hemorrhage in ten, lacunar infarction in 24, and territorial infarction in four. CONCLUSION: The incidence and number of microbleeds was greater in older patients and in those with hypertension, hypertriglycemia, and stroke lesions such as intracerebral hemorrhage or lacunar infarction. The detection of microbleeding at gradient-echo imaging is helpful, since it predicts the possibility of cerebral hemorrhage in these patients.

Traumatic Intracranial Aneurysms in Children

PURPOSE: To describe the imaging findings of traumatic intracranial aneurysms (TICA) in children. MATERIALS AND METHODS: Five boys aged 3-15 (mean, 7) years with surgically confirmed TICA were included in this study. All had a history of nonpenetrating head trauma, and they underwent precontrast CT imaging immediately after the injury and follow-up CT or MRI. In all cases, angiography revealed the presence of aneurysms, which at surgery were shown to be pseudoaneurysms with severe adhesions. RESULTS: Angiography demonstrated that all aneurysms were located in the anterior cerebral artery (ACA) or its branches. The precise locations were the A2 segment of the ACA, the site of origin of the callosomarginal artery or its first branch, or of the anterior internal frontal artery, or between the first and second branch of the pericallosal artery. In all patients, precontrast CT performed immediately after trauma depicted subarachnoid hemorrhage (SAH) in the anterior interhemispheric fissure (AIHF). Follow-up precontrast CT showed nodular high density around the anterior falx in three, recurrent SAH in the AIHF in two, and intracerebral hemorrhage (ICH) with intraventricular hemorrhage in two. In two patients with a nodular high-density lesion, nodular enhancement was demonstrated at postcontrast CT, and in one, follow-up MRI revealed a nodular signal void around the anterior falx; nodular enhancement was seen at postcontrast imaging, and MR angiogram depicted a saccular aneurysm. In one patient, MRI demonstrated infarction in the caudate nucleus and ACA territory. CONCLUSION: If, after head injury, an area of nodular high density is revealed by CT, or a signal void by MRI, or if SAH or ICH is present around the anterior falx, the possibility of TICA should be considered.

The Role of Tc-99m HMPAO Brain Perfusion SPECT in the Psychiatric Disability Evaluation of Patients with Chronic Traumatic Brain Injury / 대한핵의학회잡지

No abstract available.

A Case of Reversible Posterior Leukoencephalopathy Syndrome in Patient with Chronic Renal Failure / 대한신장학회잡지

A Reversible Posterior Leukoencephalopathy Syndrome(RPLS) consists of neurologic symptoms and signs - headache, consciousness change, seizure, visual impairment - and brain imaging finding showing brain(espicially white matter) edema usually involving the posteior parietal-temporal-occipital areas. The causes are thought to be hypertensive encephalopathy, pre-eclampsia or eclampsia, renal failure with fluid overload and immunosuppressive agents such as cyclosporin A or FK506. RPLS may usually reversible if treated early by decreasing blood pressure and discontinuing offending drugs. A 23-year-old man had been hemodialyzed with chronic renal failure for two years. His blood pressure elevated to 240/150mmHg 3 days before admission and he complained of severe headache, vomiting, and total visual loss at the day of admission. Brain T2-weighted MRI imaging showed increased signal intensity involving the both parietal, posterior temporal, and occipital lobes. After antihypertensive and dexamethason treatment, a follow-up brain MRI performed on 7 days after admission showed nearly normalized findings and all symptoms including visual loss were recovered completely in one week.

Clinical Significance of Nerve Root Enhancement in Contrast-Enhanced MR Imaging of the Postoperative Lumbar Spine

PURPOSE: To determine the significance of nerve root contrast enhancement in patients with residual or recurrent symptomatic postoperative lumbar spine. MATERIALS AND METHODS: Eighty-eight patients with 116 postoperative lumbar disc lesions causing radiating back pain underwent enhanced MR imaging. Intradural nerve root enhancement was quantified by pixel measurement, and affected nerve roots were compared before and after contrast administration. Extradural nerve root enhancement was assessed visually, and nerve root enhancement and clinical symptoms were correlated. Associated lesions such as recurrent disc herniation, scar tissue, nerve root thickening and nerve root displacement were also evaluated. RESULTS: Of 26 cases(22.4%) involving intradural nerve root enhancement, 22 (84.6%) showed significant clinical symptoms (p=0.002). and of 59 (50.9%) demonstrating extradural enhancement, clinical symptoms showed significant correlation in 47 (79.7%) (p=0.001). Nerve root enhancement, including eleven cases where this was both intra-and extradural, showed highly significant association with clinical symptoms in 74 of the 116 cases (63.8%) (p=0.000). Among 33 cases (28.4%) of recurrent disc herniation, nerve root enhancement was observed in 28 (84.8%) and in 24 of these 28 (85.7%), significant correlation with clinical symptoms was observed (p=0.000). Where epidural fibrosis was present, correlation between nerve root enhancement and clinical symptoms was not significant (p>0.05). Nerve root thickening and displaced nerve root were, however, significantly associated with symptoms(87.2% and 88.6%, respectively). CONCLUSION: In patients with postoperative lumbar spine, the association between nerve root enhancement revealed by MRI and clinical symptoms was highly significant.

Neuro-Behcet's Disease: Diagnostic Usefulness of MR Imaging

PURPOSE: To suggest the characteristic MR features and to evaluate the usefulness of MR imaging for the diagnosis of neuro-Behcet's disease. MATERIALS AND METHODS: We retrospectively reviewed the MR findings of clinically confirmed neuro-Behcet 's disease in eight patients (M:F = 7:1) ranging in age from 28 to 47 (average, 36) years. The findings were analyzed in terms of the most frequently occurring sites, signal intensities, contrast enhancement, and the changing patterns seen on follow-up MR examination. RESULTS: Seven of the eight patients had parenchymal brain lesions and the other had dural sinus thrombosis without brain parenchymal brain abnormality. In descending order of frequency, lesions involved the pons, midbrain, medulla oblongata, internal capsule, basal ganglia, thalamus, temporal lobe, and corpus callosum. The brain stem was involved in six patients, five of whom showed extensive involvement of the entire stem. In five patients, brain stem lesions showed supratentorial involvement, and in one, involvement of this region only was noted. Signal intensities of the lesions were poorly defined and extensive, especially in the brain stem, and usually showed prolongation of both T1 and T2 relaxation time. Three patients underwent follow-up examination, and this showed that while most lesions had disappeared in time, some had become small and cavitary. Initial MR examination showed that three patients had newly developed lesions as well as cavitary foci, suggesting the recurrence of disease. Contrast enhancement was noted in five of seven patients (71%), and various types, including nodular, linear, marginal, and ring. CONCLUSION: The MR features of neuro-Behcet 's disease were fairly characteristic, and in clinically unsuspicious patients might be diagnostically useful.

MRI Findings of Miliary Tuberculosis of the Brain

PURPOSE: To evaluate MRI(Magnetic Resonance Imaging) findings of miliary tuberculosis of the brain. MATERIALS AND METHODS: Six patients with miliary tuberculosis of the brain diagnosed by characteristic clinical or laboratory findings were studied with spin echo MRI before and after contrast enhancement. We retrospectively evaluated MRI findings acording to the appearance, distribution, location, and enhancement pattern of the granulomas as well as associated other abnormalities. RESULTS: In six patients, contrast-enhanced MRI of thebrain showed numerous punctate, contrast enhancing lesions scattered throughout the brain. Unenhanced MRI failed to demonstrate small granulomas except a few small foci of high signal intensity on T2-weighted images. The shapes of enhancing granulomas were homogeneous nodular enhancement in 86% of cases and small ring enhancement in 14%.98% of granulomas were smaller than 3-mm and 2% were larger. Although several lesions were located in the basalganglia, thalamus, and brain stem, the majority were located in the subpial and subarachnoid space. There was no significant difference in distribution of granulomas between the supratentorial and the infratentorial areas. Other associated abnormalities were focal meningitis in five cases and focal cerebritis in one. On chest radiograph, all patients had miliary tuberculosis in the lungs. CONCLUSION: Contrast-enhanced T1-weighted MRimaging showed numerous round, very small enhancing lesions scattered throughout the brain. The majority of lesions were located in the subpial and subarachnoid space. Contrast-enhanced T1-weighted images are helpful inthe detection and diagnosis of miliary disseminated tuberculous granulomas and meningitis.