technetium-tc-99m-exametazime and Hyperglycemia

We combined behavioral testing with brain imaging using (99m)Tc-HMPAO (Amersham Health) to identify CNS structures reflecting alterations in pain perception in the streptozotocin (STZ) model of type I diabetes. We induced diabetic hyperglycemia (blood glucose >300 mg/dl) by injecting male Sprague-Dawley rats with STZ (45 mg/kg i.p.). Four weeks after STZ-diabetic rats exhibited behaviors indicative of neuropathic pain (hypersensitivity thermal stimuli) and this hypersensitivity persisted for up to 6 weeks. Imaging data in STZ-diabetic rats revealed significant increases in the activation of brain regions involved in pain processing after 6 weeks duration of diabetes. These regions included secondary somatosensory cortex, ventrobasal thalamic nuclei and the basolateral amygdala. In contrast, the activation in habenular nuclei and the midbrain periaqueductal gray were markedly decreased in STZ rats. These data suggest that pain in diabetic neuropathy may be due in part to hyperactivity in somatosensory structures coupled with a concurrent deactivation of structures mediating antinociception.

Topics: Amygdala; Animals; Behavior, Animal; Brain; Cerebrovascular Circulation; Diabetes Mellitus, Experimental; Diabetic Neuropathies; Habenula; Hyperglycemia; Male; Neuralgia; Periaqueductal Gray; Prosencephalon; Radiopharmaceuticals; Rats; Rats, Sprague-Dawley; Reaction Time; Somatosensory Cortex; Technetium Tc 99m Exametazime; Thalamic Nuclei

Hyperglycemia may rarely be seen with visual seizures. Observation of both visual evoked potentials (VEPs) and magnetic resonance imaging (MRI) in visual status epilepticus (SE) has not been reported. We describe acute and follow-up VEP and MRI findings of a patient with hyperglycemia-related visual SE of occipital origin.. In a 59-year-old diabetic woman, complex visual hallucinations and illusions developed with < or =10 seizures per hour as an initial manifestation of nonketotic hyperglycemia.. Neurologic examination revealed ictal nystagmus to the right and continuous right hemianopsia. Ictal electroencephalography (EEG) and Tc-99m hexamethylpropylene amine oxime (HMPAO) single-photon emission computed tomography (SPECT) revealed an epileptogenic focus in the left occipital lobe. MRI with fluid-attenuated inversion recovery showed focal subcortical hypointensity and gyral hyperintensity. Follow-up MRI showed only minimal gyral hyperintensity at 6 months. The P100 amplitude of VEP was significantly higher at the right occipital area during SE, but slightly higher on the left after the patient had been seizure free for 6 months.. Occipital seizures and hemianopsia can be caused by hyperglycemia and may be accompanied by special MRI and VEP findings.

Topics: Electroencephalography; Epilepsy; Evoked Potentials, Visual; Female; Functional Laterality; Hallucinations; Hemianopsia; Humans; Hyperglycemia; Illusions; Magnetic Resonance Imaging; Middle Aged; Occipital Lobe; Status Epilepticus; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Brain Mapping; Electroencephalography; Epilepsia Partialis Continua; Functional Laterality; Humans; Hyperglycemia; Male; Middle Aged; Parietal Lobe; Regional Blood Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Aged; Brain Mapping; Cerebral Cortex; Electroencephalography; Epilepsy, Reflex; Humans; Hyperglycemia; Male; Motor Activity; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon