Which of the following is not a feature of extramedullary tumour:
Answer is D (Sacral sparing): Sacral sparing is a feature of intramedullary tumors and not extramedullary (abhors. `With extramedullary tumors there is early loss of sacral sensations (lateral spinothalamic tract). Intramedullary lesions spare sensations in the perenial and sacral areas (sacral sparing)' - Harrisons Distinguishing features between Extramedullan and Intramedullary Compression of the spinal cord (Harrisons /API medicine /Paul Bracis - Localization in clinical neurology /Fuller) Features Extra medullary' Intramedullary Pathological process Arise outside the spinal cord (extradural and intradural) and produce symptoms by compressing nerve roots, spinal cord or its vascular supply Arise within the substance of the spinal cord and produce symptoms by invading the spinal cord tracts and grey matter. Nerve root symptoms are not seen Pain * Radicular /Root pain Common Rare * Diffuse burning pain Uncommo Common (Funicular) * Veebral pain Common Uncommon (Midline back pain) Motor Weakness Occurs early Occurs late (Coicospinal tract Lower extremity is involved earlier than Upper extremity is involved earlier than lower involvement) upper extremity extremity (UMN signs) (Leg fibres in the coico spinal tract are (Leg fibres are more superficial / lateral and more superficial/lateral and hence involved early) hence involved late) Sacral sensations Lost (No sacral sparing) Spared (sacral sparing) (Sacral fibres are located outmost within (Sacral fibres are located outermost and hence the laminated arrangement of the spinothalamic tract and hence involved early) spared) Paraesthesias Less common More common (Ascending progression) (Descending prgression) Dissociative Anaesthesia Absent Present Lhermite's sign Present Absent Autonomic: Late Early with caudal lesions Bladder Bowel involvement (conus/cauda equina) (Sphincter abnormalities) CSF Proteins CSF proteins are markedly raised in CSF proteins are usually normal extradural lesion and raised in intradural extra medullary lesions (May be raised eg conus medullaris lesion) Myelogram Classic signs Classic sign 'Meniscus sign' in intadural tumors 'Expansion sign' of the cord is diagnostic of 'Brush border sign' in extradural tumors syringomylia Imaging /X-ray / CT Bony changes or changes in inter veebral discs are frequent Bony changes/Disc changes are infrequent
Early Coicospinal signs and paralysis
Root pain or midine Back --pain
Abnormal CSF
Sacral sparing