A case of lymphomatoid granulomatosis/angiocentric immunoproliferative lesion with long clinical course and diffuse brain involvement.

Lymphomatoid granulomatosis (LYG)/angiocentric immunoproliferative lesions (AIL) consist of angiocentric and angiodestructive lymphoreticular proliferation predominantly involving the lungs and other extranodal sites, such as the central nervous system (CNS). This clinical entity is considered as a B cell process related to Epstein-Barr virus (EBV) infection and EBV positive diffuse large B-cell lymphoma. The CNS is involved in 20% of cases of LYG, but initial involvement is rare. In cases without pulmonary symptoms, diagnosis may be difficult. We report a rare case involving initial progression of CNS symptoms followed by a pulmonary abnormality.A 14-year-old girl suffered from high fever, ataxic gait and paraparesis. MRI revealed diffuse T2 high signals with multiple gadolinium enhancements in the cerebellum, brain stem and cerebral white matter. Her symptoms briefly improved after steroid therapy, but ataxia gradually progressed. Dyspnea due to pulmonary interstitial involvement appeared when she was 18 years old. Steroid therapy proved effective for respiratory symptoms. At 20 years old she suffered from disseminated intravascular coagulopathy (DIC) and hemophagocytic syndrome (HPS) with respiratory symptoms and repeated seizures. Her symptoms improved after the administration of cyclophosphamide. Mild hemiparesis and gait disturbance appeared when she was 22 years old. MRI revealed new lesions at the basal ganglia and subcortical white matter, brain atrophy and diffuse T2 high intensity of cerebral white matter. Cyclophosphamide was effective and there has been no recurrence of symptoms in the last 5 years. We reviewed the non-tumorous LYG/AIL involving the CNS, and discussed the clinical features, MRI imaging and diagnosis of the LYG/AIL.

Hemodynamic aspects of Alzheimer's disease.

Neuroradiological functional imaging techniques demonstrate the patterns of hypoperfusion and hypometabolism that are thought to be useful in the differential diagnosis of Alzheimer's disease (AD) from other dementing disorders. Besides the distribution patterns of perfusion or energy metabolism, vascular transit time (VTT), vascular reactivity (VR), and oxygen extraction fraction (OEF), which can be measured with positron emission tomography (PET), provide hemodynamic aspects of brain pathophysiology. In order to evaluate the hemodynamic features of AD, PET studies were carried out in 20 patients with probable AD and 20 patients with vascular dementia (VaD). The PET findings were not included in their diagnostic process of AD. Using oxygen-15-labeled compounds, cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO(2)), OEF, cerebral blood volume, and VTT were measured quantitatively during resting state. To evaluate VR, CBF was also measured during CO(2) inhalation. There was a significant increase in OEF in and around the parietotemporal cortices, but both VTT and VR were well preserved in patients with AD. By contrast, VR was markedly depressed and VTT was mildly prolonged in patients with VaD. Thus, from the hemodynamic point of view, the preservation of vascular reserve may be a distinct difference between AD and VaD. Furthermore, this indicates a hemodynamic integrity of the vasculature in the level of arterioles in AD.