technetium-tc-99m-exametazime and Language-Disorders

Primary progressive aphasia (PPA) is rare. Only limited series have been reported with SPECT or PET. Moreover, in the majority of studies, the left-to-right asymmetry ratio was used, leading to difficulties in right hemisphere analyzes.. Twenty-nine patients with clinical criteria of PPA (Mesulam and Weintraub) were included and compared with 12 control subjects. Complete language examination was performed in all patients. SPECT was performed on a double-head gamma camera after intravenous injection of hexamethylpropyleneamine oxime (22 patients and 12 control subjects) or ethylcysteinate dimer (7 patients). Nineteen regions of interest (ROIs) were drawn on each hemisphere in all patients using the Talairach atlas. The perfusion index (PI = cortex-to-cerebellum ratio) was calculated for each ROI. Atrophy was quantified on MRI by consensus of 3 observers in 16 cortical ROIs. ANOVAs were used to compare the PI between (a). patients and control subjects, (b). patients with (n = 15) or without (n = 14) lexicosemantic abnormalities (LS+ vs. LS-) and patients with (n = 19) or without (n = 10) arthric disorders (A+ vs. A-), and (c). patients with or without atrophy.. In the 29 patients, the PI was significantly lower in the left temporopolar, left lateral temporal, left Wernicke, left parietal, and right lateral temporal cortex when compared with control subjects (P < 0.001). In LS+ patients versus control subjects, the PI significantly decreased in the left temporal cortex (lateral temporal; medial temporal; temporopolar; Wernicke), left Broca, left parietal, and right lateral temporal cortex (P < 0.001). In addition, LS+ versus LS- comparison showed a significant decrease in the left lateral, left medial temporal, and left Broca cortex (P < 0.001). In comparison with control subjects, the PI was not significantly different in A+ patients, whereas in A- patients the PI was significantly decreased in the left and right lateral temporal cortex, left Wernicke, and left parietal cortex. Moreover, the PI significantly decreased in the left lateral temporal region in A+ patients compared with A- patients. Finally, in patients without atrophy, the PI significantly decreased in the right and left lateral temporal cortex and the left parietal cortex (P < 0.01).. Our study demonstrates that right-handed patients with PPA present a decreased perfusion in the bilateral temporal cortex. Moreover, in these regions, morphologic abnormalities are preceded by perfusion abnormalities. Finally, our results show that large left temporal dysfunction occurs in patients with LS disorders.

Topics: Aged; Aphasia, Primary Progressive; Brain; Cysteine; Female; Humans; Language Disorders; Magnetic Resonance Imaging; Male; Neuropsychological Tests; Organotechnetium Compounds; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Speech Disorders; Technetium Tc 99m Exametazime; Temporal Lobe; Tissue Distribution; Tomography, Emission-Computed, Single-Photon

Findings from 99mTc-HMPAO SPECT measurements at rest in a group of 19 school-age children with specific language impairment (SLI) were compared to a group of 12 children with attention-deficit hyperactivity disorder (ADHD). The regional cerebral blood flow (CBF) distributions were different in the two groups. Children with SLI showed significantly lower CBF values in the right parietal region and in the subcortical region compared to the ADHD group. In addition, the SLI group had symmetric CBF distributions in the left and right temporal regions, whereas the ADHD group showed the usual asymmetry with left-sided hemispheric predominance in the temporal regions. The findings give further evidence for anomalous neurodevelopment with deviant hemispheric lateralization as an important factor in the aetiology of SLI. They also point to the role of subcortical structures in language impairment in childhood. Earlier focus on cortical structures in SLI research needs to be widened to include subcortical regions as well.

Topics: Adolescent; Attention Deficit Disorder with Hyperactivity; Basal Ganglia; Brain; Cerebrovascular Circulation; Child; Female; Functional Laterality; Humans; Language Disorders; Male; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Thalamus; Tomography, Emission-Computed, Single-Photon

Alterations in regional cerebral blood-flow, as determined by single-photon emission computed tomography (SPECT) using technetium [99mTc] hexamethyl propylenamine oxime, were studied in two children presenting with alternating hemiplegia of childhood. Both experienced hemiplegic episodes several times per month, despite marked improvement on flunarizine therapy. SPECT images of both patients revealed focal areas of decreased uptake of the radiotracer, representing impaired regional cerebral blood-flow during, as well as between, seizures. The interictal finding of localized areas of reduced tracer uptake suggest that long-lasting hypoperfusion could be the pathophysiological mechanism by which the slowly resolving hemiplegia, and ultimately the permanent multifocal neurological deficits, are produced.

Topics: Brain; Brain Diseases; Cerebrovascular Circulation; Child, Preschool; Female; Flunarizine; Functional Laterality; Hemiplegia; Humans; Intellectual Disability; Language Disorders; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon