technetium-tc-99m-bicisate and Hydrocephalus--Normal-Pressure

It is often difficult to distinguish idiopathic normal pressure hydrocephalus (iNPH) from other neurodegenerative disorders such as Alzheimer's disease (AD). To understand the characteristic pattern of blood flow in iNPH, we performed brain perfusion SPECT and analyzed the results by using the easy Z-score imaging system (eZIS).. Subjects were 12 patients with probable iNPH and 10 probable AD patients with prominent ventriculomegaly. They underwent brain perfusion SPECT using (99m)Tc-ethylcysteinate dimer as a tracer.. The two-tailed view display in eZIS demonstrated an obvious two-layer structure consisting of decreased blood flow around the corpus callosum and, in iNPH, enhanced perfusion in areas surrounding the cingulate gyrus in the sagittal view, while no AD cases showed these findings.. Hypoperfusion around the corpus callosum in iNPH could be, at least partially, a false-positive finding due to an insufficient anatomical standardization of SPECT images caused by an abnormally enlarged ventricle. Increased blood perfusion in the external layer adjacent to the hypoperfused area might be caused by increased radioisotope count per volume resulting from exclusion of cerebral cortex by a dilated ventricle. Our results demonstrate that a two-layer appearance revealed by the two-tailed view analysis of brain perfusion SPECT using eZIS could be a means to detect iNPH.

Topics: Aged; Aged, 80 and over; Brain; Cerebrovascular Circulation; Cysteine; Female; Humans; Hydrocephalus, Normal Pressure; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Middle Aged; Neuropsychological Tests; Organotechnetium Compounds; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon

Usually, dementia, gait disturbance and urinary incontinence are an integral part of the clinical presentation of normal pressure hydrocephalus (NPH). However, NPH with transient visual cognitive disorders has not been reported previously. We herein describe an extremely rare case of NPH that presented with transient visual cognitive disorders and long lasting visual memory disturbances that subsided after CSF shunting. A 38-years-old man developed transient prosopagnosia, topographical disorientation, color vision disturbance, and visual objective agnosia that progressed over 5 years. Magnetic resonance images showed ventriculomegaly with ischemic lesions in the paraventricular deep white matter. ECD-SPECT showed a reduction of the cerebral blood flow (CBF) in the periventricular deep white matter. Three months after CSF shunting, the radiological findings normalized with dramatic improvement of the extremely rare symptoms.

Topics: Adult; Agnosia; Cerebral Ventricles; Cerebral Ventriculography; Confusion; Cysteine; Humans; Hydrocephalus, Normal Pressure; Magnetic Resonance Imaging; Male; Memory Disorders; Organotechnetium Compounds; Prosopagnosia; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Ventriculoperitoneal Shunt