Introduction
Materials and methods
Subjects
Tumour type (WHO grade) | Number |
---|---|
Astrocytoma (grade I) | 1 |
Astrocytoma (grade II) | 7 |
Astrocytoma (grade III) | 7 |
Astrocytoma (unknown grade) | 3 |
Glioblastoma | 19 |
Gliosarcoma | 2 |
Oligodendroglioma (grade II) | 2 |
Oligodendroglioma (grade III) | 1 |
Oligodendroglioma (unknown grade) | 1 |
Oligoastrocytoma (grade II) | 2 |
Meningioma (grade I) | 4 |
Atypical meningioma (grade II) | 1 |
Malignant histiocytoma | 1 |
Metastasis | 17 |
Angioma/Cavernoma | 7 |
Brain abscess | 2 |
Total | 77 |
Morphological MRI
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Thickness sign: The precentral gyrus and its cortex layer are typically thicker than the postcentral gyrus.
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Hand knob and hook: The motor hand area in the precentral gyrus protrudes as a posteriorly directed ‘omega’- or ‘epsilon’-shaped convexity on axial planes as well as a dorsally directed ‘hook’ on sagittal images.
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Pars marginalis and bracket sign: Both partes marginales of the cingulate sulci are located behind the central sulcus on parasagittal planes. On axial sections both medial subdivisions of the postcentral gyrus form imaginary ‘brackets’ around the partes marginales of the cingulate sulci.
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Inferior frontal gyrus: On parasagittal sections the inferior frontal gyrus presents with an M-shaped configuration comprising the partes orbitalis, triangularis and opercularis, the latter being functionally associated with Broca’s motor speech area. The sulcus dorsal of the “M” disembogues into the precentral sulcus.
Functional MRI
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Cortical foot representation (contralateral to the toes moved)
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Cortical hand representation (contralateral to the fingers moved)
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Cortical tongue representation (bilateral)
Statistical analysis
Results
Localisation of the motor hand area with morphological MRI
Morphological landmarks | Affected hemisphere | Unaffected hemisphere | ||||
---|---|---|---|---|---|---|
Existent | Non-existent | Variant/Uncertain | Existent | Non-existent | Variant/Uncertain | |
Axial: | ||||||
Thickness sign | 38 | 39 | 0 | 76 | 1 | 0 |
Hand knob | 66 | 11 | 0 | 75 | 0 | 2 |
Bracket sign | 55 | 20 | 2 | 74 | 1 | 2 |
Sagittal: | ||||||
Hook | 54 | 12 | 11 | 73 | 1 | 3 |
Pars marginalis | 21 | 54 | 2 | 69 | 0 | 8 |
Inferior frontal gyrus | 39 | 16 | 22 | 51 | 0 | 26 |
Localisation of motor somatotopy with functional MRI
Functional landmarks | Existent | Severe paresis | Movement artefacts | Not investigated | Technical error |
---|---|---|---|---|---|
Fingers contralateral | 76 | 1 | 0 | 0 | 0 |
Toes contralateral | 68 | 1 | 1 | 7 | 0 |
Tongue | 67 | 0 | 0 | 7 | 3 |