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Netta Levin

Publications and source records attributed to Netta Levin.

10 recordsLinked to original sources
PubMed2006

Normal and abnormal fMRI activation patterns in the visual cortex after recovery from optic neuritis.

Recovery to normal or near normal visual acuity after an optic neuritis episode is common, despite frequent persistence of conduction abnormalities, evident in prolonged visual evoked potential (VEP) latencies. Improvement of visual function is commonly attributed to peripheral nerve recovery. However, central reorganization processes may also be involved. To assess this, we compared the patterns of fMRI activation, elicited by stimulation of the affected and the normal eye, along the visual cortical hierarchy. Activation was assessed in 8 subjects, which recovered clinically from an episode of optic neuritis but still had prolonged VEP latencies. In all patients, reduced fMRI activation was seen in V1 during stimulation of the affected eye, compared to the normal eye. The fMRI signal difference decreased in magnitude with progression along the visual hierarchy, and in some regions within the lateral occipital complex even showed the opposite preference (for the affected eye). These results may indicate a built-in robustness of the object-related areas to disruption of the visual input. Alternatively, it could reflect an adaptive functional reorganization of the cortical response to an abnormal input.

Adult↗
PubMed2006

Progressive low-grade oligodendrogliomas: response to temozolomide and correlation between genetic profile and O6-methylguanine DNA methyltransferase protein expression.

BACKGROUND: Loss of heterozygosity (LOH) on chromosomes 1p and 19q has been associated with chemosensitivity and improved prognosis in patients with oligodendrogliomas. The DNA repair enzyme O6-methylguanine DNA methyltransferase (MGMT) may induce resistance to DNA-alkylating agents. Recent studies demonstrated that temozolomide (TMZ), an oral alkylating agent, has efficacy in the treatment of patients with progressive, low-grade oligodendroglioma (LGO). However, to the authors' knowledge, limited data are available regarding the 1p/19q profile and its correlation with MGMT protein expression and response to treatment with DNA-alkylating drugs. METHODS: Adult patients with magnetic resonance imaging (MRI) findings and/or clinical deterioration compatible with progressive LGO were eligible for the study if they were radiotherapy-naive. TMZ cycles were repeated every 28 days at a dose of 200 mg/m2 daily for 5 consecutive days. Clinical and MRI data were used to evaluate outcomes, and Kaplan-Meier estimates were used to assess the median time to tumor progression (TTP). The 1p/19q status was analyzed from paired tumor-blood DNA samples using polymerase chain reaction-based microsatellite analysis. MGMT protein expression was estimated semiquantitatively by immunohistochemistry using paraffin embedded tumor sections. RESULTS: There were 28 patients who received treatment, and the median time from diagnosis to tumor progression was 33.5 months. The median number of TMZ cycles per patient was 12.5. Marked clinical improvements were recorded in 15 patients (54%), and objective responses were recorded in 17 patients (61%). The median TTP was 31 months, and the progression-free survival rate was 70% at 24 months. Loss of chromosome 1p and low MGMT protein expression were associated with objective response (P < .003 and P < .04, respectively). CONCLUSIONS: TMZ was active in patients with progressive LGO, and their response to treatment was associated with 1p deletion and low MGMT protein expression. The authors suggest the possible use of MGMT immunostaining as a surrogate marker for predicting tumor chemosensitivity.

Adolescent↗
PubMed2005

Extrathymic malignancies in patients with myasthenia gravis.

INTRODUCTION: Myasthenia gravis (MG) is considered a paraneoplastic phenomenon of thymomas in 15% of patients. Co-existence of MG with extrathymic malignancies, and an increased risk of second malignancy in patients with thymoma have been reported. Data on clinical characteristics of MG patients with extrathymic malignancies and the role of concomitant diseases and their treatment are lacking. METHODS: The clinical records of 188 consecutive MG patients were studied retrospectively. We examined whether gender, age, generalized disease, seropositivity for acetyl-choline receptor antibodies, occurrence of thymoma, immunosuppressive therapy and occurrence of other autoimmune diseases determined an increased risk for development of extrathymic malignancy. RESULTS: This group followed the typical epidemiological characteristics of MG. Thirty-three patients (17.6%) had a thymoma. Twenty-nine patients (15.4%) had 30 extrathymic malignant tumors of various origins. Only four patients with extrathymic tumors had an associated thymoma. Tumors were diagnosed between 20 years prior to and 35 years after the appearance of MG. Older age of MG onset was the only risk factor identified for development of malignancy in MG. DISCUSSION: Extrathymic malignancies are common in MG patients, especially in the older age group. There are no specific clinical features of the subgroup of MG patients with cancer. Although MG is not a paraneoplastic phenomenon of extrathymic malignancy, the association between MG and malignancy may be due to a common background of immune dysregulation.

Adult↗
PubMed2005

Category specific dysnomia after thalamic infarction: a case-control study.

Category specific naming impairment was described mainly after cortical lesions. It is thought to result from a lesion in a specific network, reflecting the organization of our semantic knowledge. The deficit usually involves multiple semantic categories whose profile of naming deficit generally obeys the animate/inanimate dichotomy. Thalamic lesions cause general semantic naming deficit, and only rarely a category specific semantic deficit for very limited and highly specific categories. We performed a case-control study on a 56-year-old right-handed man who presented with language impairment following a left anterior thalamic infarction. His naming ability and semantic knowledge were evaluated in the visual, tactile and auditory modalities for stimuli from 11 different categories, and compared to that of five controls. In naming to visual stimuli the patient performed poorly (error rate>50%) in four categories: vegetables, toys, animals and body parts (average 70.31+/-15%). In each category there was a different dominating error type. He performed better in the other seven categories (tools, clothes, transportation, fruits, electric, furniture, kitchen utensils), averaging 14.28+/-9% errors. Further analysis revealed a dichotomy between naming in animate and inanimate categories in the visual and tactile modalities but not in response to auditory stimuli. Thus, a unique category specific profile of response and naming errors to visual and tactile, but not auditory stimuli was found after a left anterior thalamic infarction. This might reflect the role of the thalamus not only as a relay station but further as a central integrator of different stages of perceptual and semantic processing.

Acoustic Stimulation↗
PubMed2004

Chemotherapy as initial treatment in gliomatosis cerebri: results with temozolomide.

The optimal therapy for gliomatosis cerebri is unclear, and the rate of response to chemotherapy is not known. Eleven radiotherapy-naive patients received a median number of 10 treatment cycles of temozolomide. An objective response was documented in 45%, and the median time to tumor progression was 13 months with a progression-free survival of 55% at 12 months. These results indicate that radiotherapy to extensive brain regions can be deferred until progressive disease is observed.

Adolescent↗
PubMed2003

Patterns of misdiagnosis of multiple sclerosis.

BACKGROUND: Multiple sclerosis is a chronic demyelinating disease of the central nervous system that presents with variable signs and symptoms. This variability in the clinical presentation may result in misdiagnosis, unnecessary referrals and misleading information to the patients. OBJECTIVES: To identify the types of misdiagnoses made on the presentation of MS. METHODS: Fifty consecutive MS patients were questioned on their early symptoms, their mental status, the disease course until the diagnosis was confirmed, and the different diagnoses they received. RESULTS: The patients had been referred to 2.2 +/- 1.3 specialists before seeing a neurologist, and learned about their disease 3.5 years after the onset of symptoms. Twenty-nine patients (58%) were initially given 41 wrong diagnoses. While the majority of women were misdiagnosed mentally, orthopedic work-up was offered to the men. Misdiagnosis of MS occurred most often in patients who presented with non-specific sensory symptoms that did not conform to a specific neurologic syndrome. The patients emphasized the fact that not knowing worsened their anxiety, whereas receiving the diagnosis enabled them to begin coping with their disease. CONCLUSIONS: MS is often overlooked when patients present with non-specific sensory complaints. The difference in type of misdiagnosis between men and women may reflect a gender-dependent bias in the way physicians interpret sensory complaints.

Adult↗
PubMedDate not supplied

Severe skin reaction related to mycophenolate mofetil for myasthenia gravis.

The authors report the development of a papulosquamous psoriatic-like skin eruption following the introduction of mycophenolate mofetil (MM) in a patient with myasthenia gravis (MG). MM is a novel and potent immunosuppressive agent that blocks purine synthesis, thus selectively inhibiting T and B lymphocyte proliferation. Favorable results in refractory and steroid-dependent MG patients have been reported in open-label studies, revealing a rapid onset of action and a safe side effect profile. Drug eruption due to toxicity or immune-mediated damage has not been reported in association with MM. A 32-year-old man with generalized seropositive MG with a highly malignant clinical course was admitted to the authors' department due to an acute papulosquamous, psoriatic-like skin eruption 1 month following treatment initiation with MM. Skin biopsy revealed sparse perivascular infiltrate of lymphocytes intermingled with few eosinophils. Treatment with high-dose steroids together with discontinuation of MM induced a gradual improvement, with complete resolution of the symptoms 2 months later. A severe and fulminant skin eruption in association with MM treatment is described for the first time in the literature. The histopathologic diagnosis of "drug eruption" is supported by the resolution of symptoms following discontinuation of MM. However, other possibilities include an immune-mediated process supported by the presence of lymphocytic infiltrations, the clinical appearance and the distribution of lesions (simulating a psoriatic-like dermatitis), as well as the marked response to steroids.

Adult↗