technetium-tc-99m-exametazime and Landau-Kleffner-Syndrome

Landau-Kleffner syndrome (LKS) is a childhood disorder of unknown etiology characterized by an acquired aphasia and epilepsy. We have performed comprehensive neurofunctional studies on an 8-year-old girl with typical LKS, with the aim of identifying lesions that may be responsible for her condition. 18F-fluoro-D-glucose (FDG) positron emission computed tomography (PET), 11C-Flumazenil (FMZ) PET, 99mTc-hexamethylpropyleneamine oxime single photon emission computed tomography (SPECT) and magnetoencephalography were performed before and after changes to the patient's medication led to a clinical improvement. Interictal SPECT showed hypoperfusion in the left frontal, left temporal, and left occipital lobes. 18F-FDG PET demonstrated a decrease in glucose metabolism medially in both temporal lobes and superiorly in the left temporal lobe. 11C-FMZ PET revealed a deficit in benzodiazepine receptor binding at the tip of the left temporal lobe. Magnetoencephalography demonstrated equivalent current dipoles located superiorly in the left temporal lobe. Our results suggest that the tip of the left temporal lobe plays an important role in the pathogenesis of LKS in our patient.

Topics: Anticonvulsants; Child; Electroencephalography; Female; Humans; Landau-Kleffner Syndrome; Magnetic Resonance Imaging; Magnetoencephalography; Positron-Emission Tomography; Seizures; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

Landau-Kleffner syndrome (LKS) is a rare childhood disorder characterized by acquired aphasia with seizures and electroencephalogram (EEG) abnormalities. Tc-99m-HMPAO SPECT was performed in three right handed children with LKS. A relative decrease in perfusion was found in the left temporal cortex of all three patients and also in the left frontoparietal cortex of one patient with hyperkinetic behavior. Degree of regional cerebral perfusion impairment did not correlate with the severity of clinical and EEG abnormalities. Asymmetrical temporoparietal perfusion appears characteristic of LKS. SPECT findings in LKS were evaluated as useful in elucidating the pathogenic features of the disorder in the brain.

Topics: Anticonvulsants; Brain; Carbamazepine; Cerebrovascular Circulation; Child, Preschool; Clonazepam; Dexamethasone; Electroencephalography; Evoked Potentials, Auditory, Brain Stem; Frontal Lobe; Humans; Landau-Kleffner Syndrome; Male; Parietal Lobe; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon; Valproic Acid

We report obtaining an ictal single photon emission computed tomographic (SPECT) scan in a right-handed 51-year-old man who had an astrocytoma in the left cerebral hemisphere and simple partial seizures characterized by aphasia. An epileptic seizure producing loss of speech and right-sided facial twitching occurred by chance during a SPECT scan. During the attack, he was unable to speak, but auditory comprehension and writing were intact. Ictal SPECT showed an area of increased perfusion in the left frontal cortex, with the area of highest perfusion involving the left frontal operculum to the inferior part of the left precentral gyrus. Interictal SPECT showed hypoperfusion in the same area. These SPECT findings suggest that the frontal operculum of the dominant hemisphere is one of the regions that can give rise to epileptic aphasia.

Topics: Astrocytoma; Brain Neoplasms; Cerebrovascular Circulation; Electroencephalography; Epilepsies, Partial; Frontal Lobe; Functional Laterality; Humans; Landau-Kleffner Syndrome; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Five right-handed children with Landau-Kleffner syndrome (LKS) who had disease onset between the ages of 3 and 9 years were studied with EEG and single-photon emission computed tomography (SPECT) before and, in four cases, after 6 months of corticosteroid treatment. EEG findings included both focal and generalized spikes as well as spike-wave discharges with bilateral temporal predominance. These increased markedly during sleep in 1 child, and continuous spike-and-wave complexes appeared during slow-wave sleep in another patient. Neuropsychological testing demonstrated verbal auditory agnosia. Magnetic resonance imaging (MRI) was performed in 4 children and was normal. Brain SPECT imaging demonstrated abnormal perfusion in the left temporal lobe in all patients. The response to corticosteroid therapy was mixed. Our findings reinforce the concept that LKS is a functional disease affecting the language-dominant brain areas. We conclude that SPECT imaging may be of diagnostic assistance in the evaluation of this syndrome of unknown etiology.

Topics: Age of Onset; Brain; Child; Child, Preschool; Electroencephalography; Female; Functional Laterality; Humans; Landau-Kleffner Syndrome; Male; Neuropsychological Tests; Organotechnetium Compounds; Oximes; Prednisone; Sleep; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon