Normal Magnetic Resonance Imaging Findings Research Articles

Brain perfusion SPECT in limbic encephalitis associated with autoantibody against the glutamate receptor epsilon 2

The aim of this study was to elucidate the single-photon emission computed tomography (SPECT) pattern at the acute stage of disease in non-herpetic limbic encephalitis (NHLE) patients associated with the N-methyl-D-aspartate-type glutamate receptor epsilon 2 (GluR ϵ2) autoantibody using Z-score imaging system (eZIS) analyses. Brain magnetic resonance imaging (MRI) and brain perfusion SPECT using technetium-99 ethyl cysteinate dimer ((99m)Tc-ECD) were performed in eight patients with NHLE (5 men and 3 women; mean age 48.8±22 years) within 20days after clinical onset. All patients had various clinical limbic-associated symptoms and no evidence of herpes simplex infection or systemic malignancies. Two of eight patients showed abnormally hyperintense lesions on diffusion-weighted images and significant hyperperfusion in ipsilateral cerebral cortex on eZIS analysis, whereas other patients showed normal MRI findings and significant hypoperfusion in one or both sides of the limbic and paralimbic areas. We suggest that (99m)Tc-ECD SPECT study using eZIS analyses may be helpful to detect the neuronal dysfunction, particularly in NHLE patients without abnormal MRI findings.

Clinical Characterization of Epilepsy of Unknown Cause in Cats

BackgroundThe diagnosis of feline epilepsy of unknown cause (EUC) requires a thorough diagnostic evaluation, otherwise the prevalence of EUC could be overestimated.HypothesisFeline EUC is a clinically defined disease entity, which differs from feline hippocampal necrosis by the absence of magnetic resonance imaging (MRI) signal alteration of the hippocampus. The objectives of this study were (1) to evaluate the prevalence of EUC in a hospital population of cats by applying well‐defined inclusion criteria, and (2) to describe the clinical course of EUC.AnimalsEighty‐one cats with recurrent seizures.MethodsRetrospective study—medical records were reviewed for cats presented for evaluation of recurrent seizures (2005–2010). Inclusion criteria were a defined diagnosis based on laboratory data, and either MRI or histopathology. Final outcome was confirmed by telephone interview with the owner. Magnetic resonance images were reviewed to evaluate hippocampal morphology and signal alterations.ResultsEpilepsy of unknown cause was diagnosed in 22% of cats with epilepsy. Physical, neurologic, and laboratory examinations, and either 1.5 T MRI and cerebrospinal fluid analysis or postmortem examination failed to identify an underlying cause. Cats with EUC had a higher survival rate (P < .05) and seizure remission occurred frequently (44.4%).Conclusion and Clinical ImportanceA detailed clinical evaluation and diagnostic imaging with MRI is recommended in any cat with recurrent seizures. The prognosis of cats with normal MRI findings and a clinical diagnosis of EUC are good. Standardized imaging guidelines should be established to assess the hippocampus in cats.

Spinal cord injury without radiologic abnormality in children imaged with magnetic resonance imaging

This study aimed to compare children diagnosed with cervical spinal cord injury without radiographic abnormality (SCIWORA) relative to whether there is evidence of cervical spinal cord abnormalities on magnetic resonance imaging (MRI). We conducted a planned subanalysis of a cohort of children younger than 16 years with blunt cervical spine injury presenting to Pediatric Emergency Care Applied Research Network centers from January 2000 to December 2004 who underwent cervical MRI and did not have bony or ligamentous injury identified on neuroimaging. We defined SCIWORA with normal MRI finding as children with clinical evidence of cervical cord injury and a normal MRI finding and compared them with children with SCIWORA who had cervical cord signal changes on MRI (abnormal MRI finding). Of the children diagnosed with cervical spine injury, 55% (297 of 540) were imaged with MRI; 69 had no bony or ligamentous injuries and were diagnosed with SCIWORA by clinical evaluation; 54 (78%) had normal MRI finding, and 15 (22%) had cervical cord signal changes on MRI (abnormal MRI finding). Children with abnormal MRI findings were more likely to receive operative stabilization (0% normal MRI finding vs. 20% abnormal MRI finding) and have persistent neurologic deficits at initial hospital discharge (6% normal MRI finding vs. 67% abnormal MRI finding). Children diagnosed with SCIWORA but with normal MRI finding in our cohort presented differently and had substantially more favorable clinical outcomes than those with cervical cord abnormalities on MRI. Epidemiologic study, level III.

Long-term Outcomes After Nonlesional Extratemporal Lobe Epilepsy Surgery

A focal lesion detected by use of magnetic resonance imaging (MRI) is a favorable prognostic finding for epilepsy surgery. Patients with normal MRI findings and extratemporal lobe epilepsy have less favorable outcomes. Most studies investigating the outcomes of patients with normal MRI findings who underwent (nonlesional) extratemporal epilepsy surgery are confined to a highly select group of patients with limited follow-up. To evaluate noninvasive diagnostic test results and their association with excellent surgical outcomes (defined using Engel classes I-IIA of surgical outcomes) in a group of patients with medically resistant nonlesional extratemporal epilepsy. A retrospective study. Mayo Clinic, Rochester, Minnesota. From 1997 through 2002, we identified 85 patients with medically resistant extratemporal lobe epilepsy who had normal MRI findings. Based on a standardized presurgical evaluation and review at a multidisciplinary epilepsy surgery conference, some of these patients were selected for intracranial electroencephalographic (EEG) monitoring and epilepsy surgery. Nonlesional extratemporal lobe epilepsy surgery. The results of noninvasive diagnostic tests and the clinical variables potentially associated with excellent surgical outcome were examined in patients with a minimum follow-up of 1 year (mean follow-up, 9 years). Based on the noninvasive diagnostic test results, a clear hypothesis for seizure origin was possible for 47 of the 85 patients (55%), and 31 of these 47 patients (66%) proceeded to intracranial EEG monitoring. For 24 of these 31 patients undergoing long-term intracranial EEG (77%), a seizure focus was identified and surgically resected. Of these 24 patients, 9 (38%) had an excellent outcome after resective epilepsy surgery. All patients with an excellent surgical outcome had at least 10 years of follow-up. Univariate analysis showed that localized interictal epileptiform discharges on scalp EEGs were associated with an excellent surgical outcome. Scalp EEG was the most useful test for identifying patients with normal MRI findings and extratemporal lobe epilepsy who were likely to have excellent outcomes after epilepsy surgery. Extending outcome analysis beyond the resective surgery group to the entire group of patients who were evaluated further highlights the challenge that these patients pose. Although 9 of 24 patients undergoing resective surgery (38%) had excellent outcomes, only 9 of 31 patients undergoing intracranial EEG (29%) and only 9 of 85 patient with nonlesional extratemporal lobe epilepsy (11%) had long-term excellent outcomes.

Placental Pathology in Full-Term Infants with Hypoxic-Ischemic Neonatal Encephalopathy and Association with Magnetic Resonance Imaging Pattern of Brain Injury

To investigate the relationship between placental pathology and pattern of brain injury in full-term infants with neonatal encephalopathy after a presumed hypoxic-ischemic insult. The study group comprised full-term infants with neonatal encephalopathy subsequent to presumed hypoxia-ischemia with available placenta for analysis who underwent cerebral magnetic resonance imaging (MRI) within the first 15 days after birth. Macroscopic and microscopic characteristics of the placenta were assessed. The infants were classified according to the predominant pattern of brain injury detected on MRI: no injury, predominant white matter/watershed injury, predominant basal ganglia and thalami (BGT) injury, or white matter/watershed injury with BGT involvement. Maternal and perinatal clinical factors were recorded. Placental tissue was available for analysis in 95 of 171 infants evaluated (56%). Among these 95 infants, 34 had no cerebral abnormalities on MRI, 27 had white matter/watershed injury, 18 had BGT injury, and 16 had white matter/watershed injury with BGT involvement. Chorioamnionitis was a common placental finding in both the infants without injury (59%) and those with white matter/BGT injury (56%). On multinomial logistic regression analysis, white matter/watershed injury with and without BGT involvement was associated with decreased placental maturation. Hypoglycemia was associated with an increased risk of the white matter/BGT injury pattern (OR,5.4; 95% CI, 1.4-21.4). The BGT injury pattern was associated with chronic villitis (OR, 12.7; 95% CI, 2.4-68.7). A placental weight <10th percentile appeared to be protective against brain injury, especially for the BGT pattern (OR, 0.1; 95% CI, 0.01-0.7). Placental weight <10th percentile was mainly associated with normal cerebral MRI findings. Decreased placental maturation and hypoglycemia <2.0 mmol/L were associated with increased risk of white matter/watershed injury with or without BGT involvement. Chronic villitis was associated with BGT injury irrespective of white matter injury.

Magnetic Resonance Imaging Findings in Pediatric Bilateral Vocal Fold Dysfunction

We studied the findings of brain magnetic resonance imaging (MRI) in infants with idiopathic congenital bilateral vocal fold dysfunction (CBVFD). We performed a retrospective investigation of a case series. We identified 26 children (14 male, 12 female) over 11 years. Three children were excluded. Thirteen patients required airway interventions, including continuous positive airway pressure (4 patients), endotracheal intubation (1), and tracheostomy (8). The findings on brain MRI were abnormal in 8 patients (35%). Tracheostomy was required in 3 patients (38%) with abnormal MRI findings, as compared with 5 of 15 patients (33%) with normal MRI findings. The MRI abnormalities involved evidence of white matter injury (2), abnormal white matter signal (1), subdural blood (3), cerebral swelling (1), and perisylvian polymicrogyria (1). The cranial ultrasound findings were abnormal in 4 of 11 patients. The MRI findings were abnormal in 2 of 7 children in whom the cranial ultrasound findings were normal, and in 2 of the 4 patients in whom the cranial ultrasound findings were abnormal. The MRI abnormalities were nonspecific; however, they may indicate unrecognized perinatal intracranial injury as being related to CBVFD. In addition, MRI may reveal an underlying structural brain anomaly. Cranial ultrasound has poor sensitivity and specificity. Hence, MRI should be considered as part of the routine assessment of neonates with CBVFD.

Surgical Outcomes in Patients With Extratemporal Epilepsy and Subtle or Normal Magnetic Resonance Imaging Findings

Surgery is an important therapeutic option in patients with medically refractory epilepsy. The combination of an extratemporal epileptic focus and nonlesional magnetic resonance imaging (MRI) was often believed to portend a poor outcome. To investigate the outcome and analyze potential prognostic predictors in patients without lesions on MRI who underwent extratemporal resections. Clinical, presurgical evaluation, invasive monitoring, and postoperative data of patients with high-resolution MRI that was initially reported as nonlesional were reviewed. Patients were reclassified as MRI-positive if an MRI abnormality related to the epilepsy was revealed at the multidisciplinary presurgical patient management conference, or as MRI-negative if imaging remained normal or revealed incidental findings. Sixty patients were identified; 72% were MRI-negative. In the original cohort, the median seizure-free duration was 1.32 years (95% confidence interval [CI], 0.16-2.0); probability of seizure freedom at 2 years was 36% (95% CI, 30%-43%). In the MRI-negative group, the median seizure-free duration was 1.52 years (95% CI, 0.12-5.17); probability of seizure freedom at 2 years was 42% (95% CI, 33%-50%). Complete resection of ictal onset areas and absence of acute postoperative seizures were significantly associated with longer seizure freedom (risk ratio 4.9, P = .004; 95% CI, 1.6-16.7 and 22.1, P < .001; 95% CI, 5.9-94.7, respectively). Among patients with medically refractory MRI nonlesional extratemporal epilepsy, detailed evaluation and subsequent resection leads to seizure freedom in 42% of patients at 2 years.

Risk of cytomegalovirus‐associated sequelae in relation to time of infection and findings on prenatal imaging

To determine the outcome of pregnancies with documented fetal cytomegalovirus (CMV) infection with and without abnormal findings on ultrasound examination and magnetic resonance imaging (MRI). In this prospective cohort study of pregnant women with documented fetal CMV infection, vertical CMV transmission occurred during the first and second trimesters following primary maternal infection. Patients underwent serial prenatal ultrasound scans and fetal MRI. All neonates underwent ocular fundus examination, ultrasound brain scan and hearing evaluation, and were then followed periodically by a pediatrician. Primary CMV infection occurred during the first and second trimesters of pregnancy in 71 and 74 patients, respectively. Seven patients (4.8%) decided to terminate pregnancy because of prenatal findings and one neonate died because of CMV complications. Patients with first-trimester infection had infants with significantly more associated sequelae (either auditory damage or neurodevelopmental disabilities) than did patients with second-trimester infection (19.7% vs 5.6%, respectively; P = 0.01). Abnormal prenatal findings on ultrasound examination were associated with increased risk of sequelae. When both ultrasound and MRI findings were normal, the rate of sequelae was decreased to 15.6% for first-trimester infections and to 2.0% for second-trimester infections, partial hearing loss being the sequela in most cases. In the presence of abnormal ultrasound and/or MRI findings the risk was 25% and 16%, respectively, and in most cases the sequelae were deafness and neurodevelopmental delay. The rate of intrauterine growth restriction (IUGR) in the study group was 11.7% and was not affected by the time of onset of maternal infection. Isolated IUGR was not associated with increased risk of sequelae. The risk of sequelae is higher following first-than second-trimester CMV infection. However, the risk of severe sequelae is significantly reduced in the presence of normal prenatal ultrasound and MRI findings.

Boys with precocious or early puberty: incidence of pathological brain magnetic resonance imaging findings and factors related to newly developed brain lesions.

PurposeBrain magnetic resonance imaging (MRI) findings and factors predictive of pathological brain lesions in boys with precocious puberty (PP) or early puberty (EP) were investigated.MethodsSixty-one boys with PP or EP who had brain MRI performed were included. PP was classified into the central or peripheral type. Brain MRI findings were categorized into group I (pathological brain lesion known to cause puberty; newly diagnosed [group Ia] or previously diagnosed [group Ib]); group II (brain lesion possibly related to puberty); and group III (incidental or normal findings). Medical history, height, weight, hormone test results, and bone age were reviewed.ResultsBrain lesions in groups I and II were detected in 17 of 23 boys (74%) with central PP, 9 of 30 boys (30%) with EP, and 7 of 8 boys (88%) with peripheral PP. All brain lesions in boys with peripheral PP were germ cell tumors (GCT), and 3 lesions developed later during follow-up. Group I showed earlier pubertal onset (P<0.01) and greater bone age advancement (P<0.05) than group III. Group III had lower birth weight and fewer neurological symptoms than "Ia and II" (all P<0.05).ConclusionEarlier onset of puberty, greater bone age advancement, and/or neurological symptoms suggested a greater chance of pathological brain lesions in boys with central PP or EP. All boys with peripheral PP, even those with normal initial MRI findings, should be evaluated for the emergence of GCT during follow-up.

Ophthalmoplegic migraine: Migraine or oculomotor neuropathy?

Ophthalmoplegic migraine (OM) is a rare condition characterized by the association of headaches and an oculomotor nerve palsy. The third cranial nerve is commonly involved in recurrent attacks, whereas involvement of the sixth and fourth nerves is uncommon. It is still debated whether an uncontrolled migraine or an oculomotor neuropathy may be the primary cause of ophthalmoplegic migraine. We report two patients affected by OM with normal magnetic resonance imaging findings and a history of uncontrolled migraine before an attack of OM. The cases reported allow us to hypothesize that OM may be considered a form of migraine rather than a cranial neuralgia. It is possible that different factors such as inflammatory or structural factors, may represent a vulnerability of the nerve during a severe migraine attack causing ophthalmoplegia.

Brain magnetic resonance imaging and motor and intellectual functioning in 86 patients born at term with spastic diplegia.

To investigate the association between magnetic resonance imaging (MRI) patterns and motor function, epileptic episodes, and IQ or developmental quotient in patients born at term with spastic diplegia. Eighty-six patients born at term with cerebral palsy (CP) and spastic diplegia (54 males, 32 females; median age 20 y, range 7-42 y) among 829 patients with CP underwent brain MRI between 1990 and 2008. The MRI and clinical findings were analysed retrospectively. Intellectual disability was classified according to the Enjoji developmental test or the Wechsler Intelligence Scale for Children (3rd edition). The median ages at diagnosis of CP, assignment of Gross Motor Function Classification System (GMFCS) level, cognitive assessment, and MRI were 2 years (range 5 mo-8 y), 6 years (2 y 8 mo-19 y), 6 years (1 y 4 mo-19 y), and 7 years (10 mo-30 y) respectively. MRI included normal findings (41.9%), periventricular leukomalacia, hypomyelination, and porencephaly/periventricular venous infarction. The frequency of patients in GMFCS levels III to V and intellectual disability did not differ between those with normal and abnormal MRI findings. Patients with normal MRI findings had significantly fewer epileptic episodes than those with abnormal ones (p=0.001). Varied MRI findings, as well as the presence of severe motor dysfunction and intellectual disability (despite normal MRI), suggest that patients born at term with spastic diplegia had heterogeneous and unidentified pathophysiology.

The efficacy of brain F-fluorodeoxyglucose positron emission tomography in neuropsychiatric lupus patients with normal brain magnetic resonance imaging findings

Brain involvement in systemic lupus erythematosus (SLE) is a significant source of morbidity and mortality. Therefore, the early detection and treatment of brain involvement in SLE is of utmost importance; however, a confirmative diagnostic tool for neuropsychiatric SLE is yet to be developed. In this study, we investigated the efficacy of (18)F-FDG-PET for detection of brain involvement in patients with SLE with normal magnetic resonance imaging (MRI) findings. Twenty patients with SLE, who presented with neuropsychiatric symptoms despite normal brain MRI findings and who underwent brain (18)F-FDG-PET, were enrolled. The most common neuropsychiatric manifestation was headache (45%), followed by seizure (20%) and mood disorder (20%). (18)F-FDG-PET revealed significant glucose metabolic abnormalities in 15 of 20 patients (75%). The temporal (55%) and the occipital (55%) lobes were the most susceptible brain regions, followed by the frontal lobe (50%). However, neuropsychiatric symptoms were not geographically correlated to (18)F-FDG-PET findings. Two patients with abnormal (18)F-FDG-PET findings underwent follow-up brain (18)F-FDG-PET after remission, which showed complete resolution of abnormal glucose metabolism. Our data suggest that (18)F-FDG-PET may be an additional diagnostic modality complementary to MRI, when MRI is unable to provide evidence of brain involvement in patients with SLE.

Anti-NMDA-receptor encephalitis presenting as postpartum psychosis in a young woman, treated with rituximab

A severe paraneoplastic form of acute encephalitis associated with antibodies against the N-methyl D-aspartate (NMDA) receptor typically occurs in young individuals and is associated, but not always, with an underlying tumor. If diagnosed early, initiation of immunotherapy and tumor removal (if present) may result in recovery. We report a case in a 25-year-old young woman who presented to our medical center with postpartum psychosis. Treatment with rituximab (a chimeric monoclonal antibody against the protein CD20) resulted in gradual improvement in mental status and resolution of seizure activity episodes. A year after diagnosis and treatment, the patient was doing well without recurrences, and no tumors appeared. This is the first described case of anti–NMDA-receptor antibodies encephalitis that presented initially as a postpartum psychosis disorder and was successfully treated with rituximab.

Endocrinological outcomes of pure endoscopic transsphenoidal surgery: a Croatian Referral Pituitary Center experience

AimTo analyze early remission, complications, and pituitary function recovery after pure endoscopic endonasal transsphenoidal surgery (PEETS), a novel method in pituitary adenoma treatment.MethodsTesting of all basal hormone values and magnetic resonance imaging (MRI) were performed preoperatively and postoperatively (postoperative MRI only in nonfunctioning adenomas) in 117 consecutive patients who underwent PEETS in the period between 2007 and 2010. The series consisted of 21 somatotroph adenomas, 61 prolactinomas, and 4 corticotroph and 31 nonfunctioning adenomas. Sixty-three were macroadenomas and 54 were microadenomas. Remission was defined as hormonal excess normalization on the seventh postoperative day in functioning adenomas and as normal MRI findings approximately four months postoperatively in nonfunctioning adenomas. The presence of hypogonadism, growth hormone deficiency, and hypothyroidism was assessed on the seventh postoperative day. Hypocortisolism was assessed through necessity for replacement therapy within 18 months postoperatively.ResultsRemission was achieved in 84% of patients: in 100% of microadenoma and 70% of macroadenoma patients (P < 0.001, odds ratio [OR], 28.16, 95% confidence interval [CI], 1.61-491.36), respectively. Endocrinological complications occurred in 17.1% of patients: in 9% of microadenoma and 24% of macroadenoma patients (P = 0.049, OR, 3.06; 95% CI, 1.03-9.08). Duration of empirical hydrocortisone replacement therapy was significantly shorter in microadenoma patients (P < 0.001). Thirty-five percent of preoperatively present hormonal deficiencies improved after the surgery. Between tumor types there were no significant differences in remission, complications, and normal pituitary function recovery.ConclusionPatients with microadenomas had higher remission and lower complication rates following PEETS, emphasizing the necessity for early detection and treatment of pituitary adenomas. PEETS is a discussion-worthy method for microprolactinoma treatment.

Age-related changes in normal adult pancreas: MR imaging evaluation

ObjectiveTo investigate age-related changes in normal adult pancreas as identified by magnetic resonance imaging (MRI). Materials and methodsWe examined 115 patients without pancreatic diseases (21–90 years) who underwent upper abdominal MRI to evaluate the normal pancreatic MRI findings related to aging. The parameters examined were the pancreatic anteroposterior (AP) diameter, pancreatic lobulation, pancreatic signal intensity (SI), depiction of the main pancreatic duct (MPD), grade of the visual SI decrease on the opposed-phase T1-weighted images compared with in-phase images, and enhancement effect of the pancreas in the arterial phase of dynamic imaging. ResultsThe pancreatic AP diameter significantly reduced (head, p=0.0172; body, p=0.0007; tail, p<0.0001), and lobulation (p<0.0001) and parenchymal fatty change (p<0.0001) became more evident with aging. No significant correlation was observed between aging and pancreatic SI, however the SI on the in-phase T1-weighted images tended to decrease with aging. No significant correlation was observed between aging and the depiction of the MPD as well as aging and contrast enhancement. ConclusionMRI findings of pancreatic atrophy, lobulation, and fatty degeneration are characteristic changes related to aging, and it is necessary to recognize these changes in the interpretation of abdominal MRI in patients with and without pancreatic disease.

Cranial magnetic resonance imaging findings of nutritional Vitamin B12 deficiency in 15 hypotonic infants

BackgroundNutritional vitamin B12 deficieny is common among infants in the developing and underdeveloped countries. There is limited information concerning neuroimaging findings in infants with vitamin B12 deficiency in the literature. AimsThe aim of this study is to evaluate the cranial magnetic resonance imaging (MRI) changes and clinical characteristics of hypotonic infants due to vitamin B12 deficiency. Materials and methods: A total of 15 infants with neuroradiologic investigations were diagnosed with nutritional B12 vitamin deficiency. Cranial MRI was performed on all infants. ResultsFive infants were female (33%) and the mean age of infants was 12.3 ± 5.5 months. Hypotonia and neurodevelopmental retardation were present in all patients. MRI demonstrated thinning of the corpus callosum in 6 (40%), cortical atrophy in 5 (33.3%), large sylvian fissures in 5 (33.3%), ventricular dilatation in 3 (20%), asymetric large lateral ventricle in 2 (13.3%) and delayed in myelination in 2 (13.3%) patients. Four infants had normal MRI findings. ConclusionBecause of the importance of vitamin B12 in the development of the brain, MRI findings may be detected and useful in infants with vitamin B12 deficiency.

Study on the significance of MRI and cerebrospinal fluid cytology in the diagnosis of viral encephalitis (meningitis)

Objective To explore the significance of magnetic resonance imaging (MRI) and cerebrospinal fluid cytology in the diagnosis and treatment of viral encephalitis (meningitis). Methods The head MRI and cerebrospinal fluid data of 189 patients with viral encephalitis (meningitis) were reviewed, and early changes of cerebrospinal fluid cyotology of patients with normal or abnormal MRI findings were analysed retrospectively. Results Among 189 viral encephalitis (meningitis) patients, 96 (50.79%) patients presented abnormal MRI, and 129 (68.25%) patients presented abnormal cerebrospinal fluid cytological findings. In patients with abnormal MRI the abnormality rate of cerebrospinal fluid cytological findings was 72.92% (70/96), while in patients with normal MRI it was 63.44% (59/93), the difference was significant (P = 0.000). Conclusion In the early stage of viral encephalitis (meningitis) MRI changes appear later than abnormal cerebrospinal fluid cytological findings, but both of them are important for clinical diagnosis and treatment of this disease. DOI：10.3969/j.issn.1672-6731.2011.05.013

Exploring the Association between Retinal Nerve Fiber Layer Thickness and Initial Magnetic Resonance Imaging Findings in Patients with Acute Optic Neuritis

Background. Recent studies have shown that OCT-measured retinal nerve fiber layer (RNFL) values may represent a marker for axonal damage in the anterior visual pathway of optic neuritis (ON) and multiple sclerosis (MS) patients. The goal of this study was to determine the link between RNFL values and initial magnetic resonance imaging (MRI) evidence of central nervous system (CNS) inflammation in patients with acute ON. Methods. Fifty patients who experienced ON as a clinically isolated syndrome (CIS) were followed for a mean period of 34 months with OCT testing. RNFL values in affected (ON) eyes and clinically unaffected (non-ON) eyes were compared between patients with MRI evidence of white matter lesions and those with normal baseline MRI findings, over a two year period. Findings. Twenty-one patients (42%) developed clinically definite MS (CDMS) during the study. After two years, temporal RNFL values were thinner (P = .07) in ON patients with MRI lesions at baseline, but the results were not significant. Conclusions. There is no association between RNFL values and baseline MRI status in ON patients at risk for future CDMS over a two year period.

Giant Congenital Melanocytic Nevi in Neonates: Report of Two Cases

Giant congenital melanocytic nevi are rare, with an estimated incidence of approximately 1 in 20,000 live births. They increase the lifetime risk for malignant melanoma and neurological deficits, including leptomeningeal melanocytosis and epilepsy. Recently, we encountered two patients in whom giant congenital melanocytic nevi were noted at birth. Case 1 presented with the largest nevus spreading across the posterior scalp, neck, chest wall, shoulder and upper back. At the age of 2 months, magnetic resonance imaging (MRI) was performed and no leptomeningeal melanocytosis was found. Case 2 presented with a huge nevus covering most parts of the lower abdomen, lower back, buttocks and bilateral upper thighs. She also had normal MRI findings in the newborn period. At the age of 7 years, leptomeningeal thickening on the surface of the junction between the pons and midbrain was found on brain MRI although she was neurologically asymptomatic. Here, we describe these two cases with congenital melanocytic nevi and review the literature about its clinical manifestations, outcomes, risks for malignant melanoma and neurocutaneous melanosis, and possible surgical interventions.

Pituitary Teratoma Presenting as Central Diabetes Insipidus with a Normal MRI Finding

Dear Sir, Central diabetes insipidus (DI) is a diverse condition characterized by polydipsia and polyuria due to a defect of arginine vasopressin. Known conditions for this disorder include inflammatory, autoimmune, traumatic brain injury, and brain tumors. Brain tumors such as craniopharyngioma1 and germinoma2 are associated with Central DI. Up to 50 percent of cases of central DI are thought to be idiopathic in nature.3,4 Herein we describe an interesting case of a 17-year-old man who was diagnosed with central DI, initially thought to be idiopathic but found to have pituitary teratoma. A 17-year-old male was admitted to our hospital with a 4-month history of polyuria and polydipsia with severe thirst. Initial laboratory work revealed serum BUN 8.4 mg/dL, creatinine 0.65 mg/dL, sodium 147 mEq/l, potassium 3.9 mEq/L, chloride 108 mEq/L, calcium 9.1 mg/dL, phosphate 4.6 mg/dL, fasting plasma glucose 109 mg/dL, and hemoglobinA1C 6.0%. A thyroid function test was normal. Plasma osmolarity was 291 mOsm/kgH2O and urinary osmolarity was 79 mOsm/kgH2O. His urine output was 4 to 5 liters per day without glycosuria. Urine osmolarity increased from 115 to 297 mosm/Kg H2O after 6 hours of water deprivation. Two hours later, urine osmolarity was still under 300 mosm/KgH2O (296 mosm/KgH2O) and the serum level of the antidiuretic hormone (ADH) level was < 0.4 pg/mL. After using nasal spray with 1-desamino-8-D-arginine vasopressin (DDAVP) 10 µg, his urine osmolarity increased from 296 to 600 mosm/KgH2O. His clinical course and laboratory finding led us to suspect Central DI. No abnormality was detected in a brain MRI (Fig. 1A). A complete work-up result to find the cause of Central DI was negative and his central DI was thought to be due to idiopathic cause. Fig. 1 (A) Initial brain MRI showed normal signal intensity in the posterior pituitary gland. (B) Follow-up MRI showed 3.3 cm sized lobulated solid mass on the sella and supurasellar area involving hypothalamus and optic chiasm. He was treated with 10 µg of desmopressin nasal spray every night. His urine volume decreased to around 2 L/day. He was discharged with DDAVP and was followed monthly in an outpatient clinic. After 45 months, he presented with a headache and diplopia persisting for 1 month. A brain MRI was completed, which showed a 3.3 cm sized lobulated solid mass involving the sellar and suprasellar area (Fig. 1B). He underwent a transspenoidal excision biopsy and the biopsy result was confirmed by pituitary teratoma. He received chemotherapy and radiation therapy. Magnetic resonance imaging (MRI) is the best imaging technique for detecting subtle abnormalities of the hypothalamic-pituitary region.5 Idiopathic central DI is a diagnosis of exclusion, and is diagnosed when central DI occurs in the absence of any alteration that is known to be responsible for DI.2,5 Central DI can precede overt brain tumors. Therefore, even though idiopathic central DI is diagnosed initially with a normal brain MRI, we may need a periodic clinical follow-up and thus serial brain MRIs to detect occult brain lesions.2,6