Spect (HMPAO) Support for Activation of the Medial Prefrontal Cortices during Toe Graphaesthesia

Abstract

This experiment was designed to test the construct validity of psychometric analyses that suggested a strong functional association between the accuracy for toe graphaesthesia and selective activation of neurons within the medial prefrontal regions. Single Photon Emission Computerized Tomography (SPECT) profiles were obtained for three volunteers (2 men, 1 woman) after they had been exposed to a toe graphaesthesia task or had been exposed to the control setting. The two measurements for each participant were separated by at least one week. Qualitative evaluation, using criteria employed for clinical diagnoses, of serial coronal, sagittal, and horizontal sections clearly indicated a specific increase in uptake of tracer within the rostral one-third to one-half of the medial prefrontal cortices of all three subjects during the toe graphaesthesia task compared to that during baseline conditions. The results are consistent with our neuropsychological research which indicates that toe graphaesthesia may be an accurate and useful indicator of the functional integrity of the medial surfaces of the anterior cerebral hemispheres.

Replace Psychometric Inferences with Direct Brain Measurements: LORETA Reflects Traditional Cerebral Loci for Neuropsychological Tests

“…According to traditional interpretations the accuracy or speed, compared to normative data, by which a subject completes each test reflects the integrity of function within the right prefrontal (dorsal convexity) region for the Category Test [14] [15] the right superior temporal cortices for the Seashore Rhythm Tests [16], the left superior temporal cortices for the Speech Sounds Test [17] [18], the right orbital frontal region for the Conditioned Spatial Association Test and the right more rostral prefrontal region for the Design Fluency Test [19]. Toe Gnosis was more associated with activity within the medial (paracentral) lobule of the parietal lobe while activity within the medial rostral prefrontal region has been shown by SPECT to be activated during Toe Graphaesthesia stimulation [5].…”

“…Results from this study indicated that even after modifications were made to the testing procedure there was significant activation in the left frontal regions including the dorsolateral prefrontal cortex and regions involved with motor control. In addition to the trail making tests, common neuropsychological tests that have been studied in this manner include the Stroop test [3] [4], the toe Graphaesthesia test [5], and the California verbal learning test [6].…”

Spectral power, source localization and microstates to quantify chronic deficits from ‘mild’ closed head injury: Correlation with classic neuropsychological tests

“…Individuals with a moderate-severe impairment scored significantly higher on this scale than those with no impairment [F (2,21) (Figure 3). This result indicates that those individuals with a moderate-severe impairment have experienced significantly more worry, anxiety and tension than those with no impairment.…”

“…In both clinical practice and following experimental analyses it has been found that toe graphaesthesia, which involves activity within the medial prefrontal lobe according to SPECT analyses [21], also reflects general impairment when the medial surface is involved. There was a significant difference in toe Graphaesthesia errors as a function of the three groups of Halstead-Reitan defined impairments [F (2,21) …”

“…There was a significant difference in toe Graphaesthesia errors as a function of the three groups of Halstead-Reitan defined impairments [F (2,21) …”