Technetium-99m hexamethylpropylene amine oxime single photon emission tomography in febrile convulsions

Abstract

We report our initial experience with technetium-99m hexamethyl propylene amine oxime (99mTC-HMPAO) brain single photon emission tomography (SPET) in the investigation of 19 children presenting with febrile convulsions. Two patients with complex febrile convulsions showed focal SPET lesions contralateral to the neurological deficit. However, in 9 out of 17 patients with simple febrile convulsions, focally disturbed perfusion was shown. In 4 out of 6 patients with electroencephalogram (EEG) abnormalities on admittance, SPET revealed at least 2 focal lesions. The temporofrontal region was the one most commonly involved. The SPET findings presented here also suggest a temporal relationship with the febrile convulsions, with markedly fewer lesions if examined after 12 days. In our initial experience, perfusion SPET did not show any particular pattern helpful in the differential diagnosis of the child presenting with febrile convulsions. Physiopathologically, our findings may support the hypothesis that brain tissue is regionally more vulnerable to fever, in patients presenting with febrile convulsions.

Spinal Fluid Cytokine Levels and Single-Photon Emission Computed Tomography Findings in Complex Febrile Seizures

“…In a previous study, 9 of 17 patients with simple febrile seizures exhibited abnormal SPECT findings on days 2 to 21 after seizure onset; both (2 of 2) patients with complex febrile seizures also exhibited abnormal SPECT findings 14 days after seizure onset. 6 In a recent study, the authors evaluated 127 Japanese pediatric patients clinically suspected as having initial-stage acute encephalopathy. The authors focused on patients with symptoms indistinguishable between complex febrile seizures and acute encephalopathy; in 9 of 14 such patients, SPECT findings revealed areas of hypoperfusion on days 1-13 after seizure onset ( Figure 2).…”

“…Cytokines are considered to be involved in the pathogenesis of febrile seizures and acute encephalopathy. 5 –10 For initial diagnosis of acute encephalopathy, the authors had previously reported that single-photon emission computed tomography (SPECT) might not be suitable by differentiating acute encephalopathy from convulsive disorders with pyrexia. 5 However, SPECT studies in patients with febrile seizures are very limited.…”

“…5 However, SPECT studies in patients with febrile seizures are very limited. 6 In this study, the authors evaluated SPECT findings and cerebrospinal fluid cytokine levels in complex febrile seizures.…”

Single-Photon Emission Computed Tomography Is an Ambiguous Imaging Method on Initial Diagnosis for Acute Encephalopathy

“…21 In another study, approximately half (11/19) the patients with febrile seizures exhibited areas of hypoperfusion on 2 to 21 days after seizure onset. 22 Patients with febrile seizures may frequently exhibit abnormal SPECT findings. In patients with epilepsy, the region of origin of the epilepsy is detected as an area of hyperperfusion during the ictal phase and as an area of hypoperfusion during the interictal phase.…”