Turkish Neurosurgery 8: 114 - 118, 1998 Cosmi: Reserl'e Capaci~\' Is Lumbar Spinal Reserve Capacity on CT-Myelography Significant? BT Miyelografide Lomber Omurga Kanali Yedek Kapasitesi Önemli midir? T. ERHAN COSAN, BAKI ADAPINAR, ALI ARSLANTAS, ESREF TEL, FEZZAN SAHIN Osmangazi University Medical Faculty Departments of Neurosurgery (TEC, AA, ET), Radiology(BA), and Biostatistics (FS), Eskisehir, Turkey Abstract: A statistical comparison is made between neurological conditions and areas of lower lumbar spinal structures, as ascertained by CT-myelography, in patients with lumbar complaints. CT-myelography was taken of 38 patients with low back pain andi or radicular pain complaints, most of whom were suffering disc herniation. Measurements of cross-sectional area of spinal cana\, dural sac, disc herniation beyond interspace (where appropriate) and ligamentum flavum were taken in 43 levels. These were levels L4-S and LS-Si lumbar disc hernia was assumed prediagnostically every case. The spinal reserve capacity area was calculated by substracting the rest from the spinal canal area. The ratio between spinal canal and dural sac area as well as that between spinal canal area and spinal reserve capacity were separately calculated for each level. These ratios were then examined for possible correlation with the neurological condition of the patients. Statistical analyses show the neurological condition of the patient to be in relation to reduction of spinal reserve capacity area rather than to reduction of dural sac area. This result is particularly marked at the LS-Si level. An evaIuation of spinal reserve capacity is appropriate as an aid to investigations of clinical status, particularly of cases with lower lumbar complaints. Key Words: CT-myelography, herniated nucleus pulposus, spinal canal dimensions 114 Özet: Lomber yakinmalari olan hastalarda BT- Miyelografi ile saptanan alt lomber spinal yapilarin alani ile nörolojik durumlari arasinda istatistiksel karsilastirma yapildi. Bel agrisi ve i veya radiküler agri sikayetleri olan ve çogunlugunda disk hemiasyonu var olan 38 hastaya BT - Miyelografi uygulandi. Spinal kanal, dural kese, interspace boyunca disk herniasyonu ve ligamentum flavum bölgelerinin 43 seviyede kesitsel ölçümleri yapildi. Ölçümler teshis öncesi düsündügümüz L4-S, LS-Silomber disk hernisi seviyelerine uygulandi. Spinal yedek kapasite alani, spinal kanal alanindan geri kalani çikararak hesaplandi. Spinal kanal ve dural kese alani arasindaki oran ile spinal kanalin alani ve spinal yedek kapasitesi arasindaki oran her seviyede ayri ayri ölçüldü. Sonra bu oranlar hastanin nörolojik durumu ile muhtemel bir korelasyon için incelendi. Istatistiksel analizler hastanin nörolojik durumunun dural kese alanindaki azalmadan çok spinal reserv kapasite alanindaki azalmayla iliskili oldugunu gösterdi. Bu sonuç özellikle LS-Si seviyelerinde belirgindi. Spinal yedek kapasitesinin degerlen- dirilmesinde, özellikle alt lomber yakinmasi olan hastalarin klinik durumlarinin arastirilmasinda yardimci olacagi düsünüldü. Anahtar Sözcükler: BT -Myelografi, nükleus pulposus herniasyonu, spinal kanal ölçümleri