technetium-tc-99m-exametazime and Status-Epilepticus

Peri- and postictal changes on both anatomic and functional imaging examinations have been recognized for many years. With the wide availability of magnetic resonance imaging and positron emission tomography, a growing range of recognized acute imaging findings have been described. Periictal and postictal findings can be classified as either local or remote, with respect to the site of maximal ictal EEG abnormality. Although many of the findings described are reversible, the factors that determine whether findings will resolve are incompletely understood. This article considers the range of findings that have been described, places them into the context of known or hypothesized pathophysiologic mechanisms, and considers their clinical significance. A framework is proposed for considering the relation between ictal duration and severity, the characteristics of imaging abnormalities, and the mechanism of their underlying pathophysiology.

Topics: Adult; Brain; Child; Diffusion Magnetic Resonance Imaging; Electroencephalography; Female; Fluorodeoxyglucose F18; Humans; Infant; Magnetic Resonance Imaging; Status Epilepticus; Technetium Tc 99m Exametazime; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon

SPECT/TC con 99mTc-HMPAO en la encefalitis progresiva mediada por anticuerpos anti-GAD.

Topics: Aged; Autoantibodies; Autoantigens; Autoimmune Diseases of the Nervous System; Cerebral Cortex; Diagnosis, Differential; Encephalitis; Fatal Outcome; Female; Glutamate Decarboxylase; Humans; Multimodal Imaging; Neuroimaging; Paraneoplastic Syndromes, Nervous System; Radiopharmaceuticals; Status Epilepticus; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

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

In this study, technetium 99m hexamethylpropyleneamine oxime (99mTc-HMPAO) single photon emission computed tomography (SPECT) was performed on 18 asphyxiated and epileptic children who also had a status epilepticus episode, and the results were compared with those for 21 children without a status epilepticus episode. All patients underwent a detailed neurologic history, interictal electroencephalography, computed tomography, and/or magnetic resonance imaging. Visual evaluation of the SPECT study showed that 16 patients of group 1 had 56 hypoperfused regions in cerebral blood flow. However, in group 2, visual evaluation showed only six detectable hypoperfusion areas in five patients. When an asymmetric index value of 3 was considered as a cutoff point, 82 regions in group 1 and 57 regions in group 2 were above this value after the quantitative SPECT evaluation. The mean number of pathologic brain regions was found to be higher in group 1 (5.1 +/- 4.3) than in group 2 (2.7 +/- 2.4) (P = .014). The localization of hypoperfused regions that were observed in temporal and frontal regions was generally similar in both groups. In conclusion, the functional activities of the brain vary in both asphyctic and epileptic children, with and without status epilepticus. These children might be candidates for refractory convulsive disease, and interictal SPECT can be a reliable method for the detection of brain lesions in these patients.

Topics: Adolescent; Asphyxia Neonatorum; Brain; Case-Control Studies; Cerebrovascular Circulation; Child; Child, Preschool; Female; Humans; Infant; Infant, Newborn; Male; Radiopharmaceuticals; Status Epilepticus; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Periodic lateralised epileptiform discharges (PLEDs) can be seen associated to nonconvulsive status epilepticus (NCSE), although their pathophysiological meaning remains questionable. Functional neuroimaging has suggested that, in this setting, PLEDs may indeed be an ictal pattern. In this report we describe perfusional changes in a patient with AIDS, PLEDs and NCSE.. A 37-year-old man with AIDS, cryptococcosis and recurrent epileptic seizures was admitted. After initial treatment, he remained comatose, and had MRI and serial EEG recordings performed. Technetium-99m-ethyl cysteinate dimer (99mTc-ECD) SPECT scans were also obtained, before and after continuous benzodiazepine infusion.. EEG disclosed PLEDs over the right fronto-polar region while MRI revealed meningeal thickening and scattered unspecific findings. SPECT revealed marked focal hyperperfusion overlapping the areas with PLEDs, both resolved after continuous midazolam infusion and clinical improvement.. This report demonstrates association of PLEDs, NCSE, and focal hyperperfusion on SPECT, additionally supporting the concept of PLEDs as an ictal pattern. Considering that status epilepticus may eventually not be detected by conventional approaches alone, we advocate the use of functional neuroimaging to assess suspected patients with impaired consciousness.

Topics: Acquired Immunodeficiency Syndrome; Adult; Electroencephalography; Functional Laterality; Humans; Hyperemia; Male; Periodicity; Radiopharmaceuticals; Status Epilepticus; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Periodic lateralized epileptiform discharges (PLEDs) are a well defined electroencephalographic entity but whether PLEDs represent an ictal condition or not remains debated. Much work has been done using electroencephalography (EEG) but new approaches using cerebral perfusion imaging may give more information about this question. We aimed to evaluate if PLEDs were associated with high regional cerebral blood flow (rCBF). We studied 18 patients with PLEDs and different pathologies, and performed brain single-photon-emission computed tomography (SPECT) during and, for three cases, after the disappearance of PLEDs. Qualitative variations and locations of rCBF were compared with PLEDs. Association with seizures and type of seizures were also assessed. SPECT showed high rCBF in 18/18 patients (100%). The location of PLEDs and high rCBF matched in 17/18 cases (94%). In the three cases where SPECT was performed after PLEDs disappeared, the high rCBF had cleared (100%). Eighteen cases (100%) presented seizures before recording of PLEDs, mainly motor (partial motor or generalized tonic-clonic). Where there was a decreased rCBF (related to a lesion) there was little relationship to PLEDs and all patients with decreased rCBF had an adjacent increased rCBF. These results confirm preliminary case reports. Hyperperfusion adds further to the argument that PLEDs may be related to a form of partial status epilepticus.

Topics: Aged; Aged, 80 and over; Brain; Cerebrovascular Circulation; Electroencephalography; Female; Functional Laterality; Humans; Male; Middle Aged; Occipital Lobe; Parietal Lobe; Periodicity; Radiopharmaceuticals; Retrospective Studies; Status Epilepticus; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

We performed technetium-99m-hexamethylpropylene- amineoxime (Tc-HMPAO) single photon emission computed tomography in two patients with prolonged hemiconvulsions followed by transient hemiparesis (Todd's paralysis). In both cases, a prolonged post-ictal cerebral hyperperfusion state of approximately 24 h was observed, even after the neurological deficits had resolved. The cerebral hyperperfusion in both cases was of much longer duration than that in previously reported cases of single and uncomplicated focal seizures. The prolonged cerebral hyperperfusion might have been due to impairment of the cerebrovascular autoregulation in seizures followed by Todd's paralysis.

Topics: Cerebrovascular Circulation; Child, Preschool; Female; Humans; Infant; Male; Paralysis; Status Epilepticus; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

We demonstrate clinical data and findings of MRI, transcranial Doppler (TCD), single photon emission computed tomography (SPECT) and electroencephalography (EEG) in an 8 month follow-up study of a 15 year old girl who developed focal status epilepticus with sensory and visual illusions. EEG showed right temporal and occipital seizure activity and attenuation of the alpha activity with right predominance. MRI showed a right temporo-parietal hyper signal on the T2 weighted images involving the cortex with sulcal effacement. MRI-angiography suggested insufficient flow in the right transverse sinus. TCD detected an elevated flow velocity in the ipsilateral middle cerebral artery during status epilepticus, corresponding to an increased perfusion of the epileptic area revealed by SPECT. After normalization of the TCD finding, the MRI detected persistent cortical abnormality beyond the 70th day after admission. MRI normalized on the 103rd day of follow-up. Serial EEG frequency analysis demonstrated the recovery of alpha peak frequency on the left side, but the attenuation of rhythmic signals remained persistent on the right. In our case, the restitution of postictal EEG lag behind the consolidation of MRI signal abnormality.

Topics: Adolescent; Cerebrovascular Circulation; Electroencephalography; Female; Follow-Up Studies; Humans; Parietal Lobe; Status Epilepticus; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon; Ultrasonography, Doppler, Transcranial

In this paper we correlate the findings on 99mTc-HMPAO brain SPECT with the results of clinical examinations and electroencephalography to determine the utility of SPECT in the evaluation of patients with suspected status epilepticus.. Thirteen patients with suspected status epilepticus underwent serial neurologic examinations, serial electroencephalograms, CT/MRI scanning and 99mTc-HMPAO SPECT. Seven patients were diagnosed with status epilepticus and six patients received other neurological diagnoses.. All patients with status epilepticus at the time of the brain SPECT scan demonstrated focal hyperperfusion on SPECT in an area concordant with that suggested by EEG. One patient with status epilepticus demonstrated a persistent area of hyperperfusion on SPECT 24 hr after the cessation of status with no evidence of breakdown in the blood-brain barrier demonstrated by 99mTc-DTPA SPECT. No patient in this study without a diagnosis of status epilepticus had focal areas of hyperperfusion on SPECT.. We suggest that a 99mTc-HMPAO SPECT scan demonstrating focal hyperperfusion in a patient being evaluated for partial status epilepticus is nonspecific. Even in the absence of a structural lesion causing local breakdown in the blood-brain barrier, it may indicate either ongoing status epilepticus or recently terminated status. However, a SPECT scan demonstrating no area of focal hyperperfusion argues against the diagnosis of partial status.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Brain; Cerebrovascular Circulation; Electroencephalography; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Organotechnetium Compounds; Oximes; Status Epilepticus; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed