title: Temporal changes of spinal subarachnoid space patency after graded spinal cord injury in rats.
abstract: BACKGROUND
  Disturbances in spinal subarachnoid space (SSAS) patency after SCI have been reported as an incidental finding, but there is a lack of information on its in vivo extent and time course. For substances and cells carried in the cerebrospinal fluid (CSF) to reach damaged neural tissue and promote reparative processes, CSF must be able to flow freely in SASS.
  
  
  OBJECTIVE
  To characterise the extent and time course of SSAS patency disruption in vivo in a rat model after graded SCI.
  
  
  METHODS
  Anaesthetised rats were subjected to mild or severe cord contusion at T9. Estimation of SSAS patency was carried out at 1h and 1, 3, 7, 15, 30 and 90 days postinjury, as well as in naïve rats, by quantifying the passage of superparamagnetic beads injected into the CSF at the cisterna magna and recovered at spinal level L2. CSF volume recovery was measured simultaneously. Data were analysed by the two-way ANOVA test.
  
  
  RESULTS
  Estimation of SSAS patency revealed nearly complete blockage early after contusion that was unevenly restored entering the chronic stages. Volume of CSF recovered was also significantly decreased early after injury compared to naïve rats, but was fully restored by 1 month postinjury. Overall, although modestly different from each other, changes in both parameters were more pronounced after severe rather than mild injuries for each time point examined.
  
  
  CONCLUSIONS
  SCI alters SSAS patency. Its extent is a function primarily of time elapsed after lesion and secondly of injury severity. It is reasonable to expect that disturbances in SASS patency might alter CSF dynamics and impair self-reparative mechanisms and intrathecal therapeutics, making SSAS patency blockage a key target for SCI management.
authors.affiliation: Department of Biochemistry, Instituto Nacional de Rehabilitacion, Mexico City, Mexico; Department of Experimental Surgery, Proyecto Camina A.C., Mexico City, Mexico.
authors.forename: Rebecca E
authors.initials: RE
authors.lastname: Franco-Bourland
authors.affiliation: Department of Neurology, School of Veterinary Medicine, UAEM, Toluca, Mexico.
authors.forename: Horacio J
authors.initials: HJ
authors.lastname: Reyes-Alva
authors.affiliation: Department of Biochemistry, Instituto Nacional de Rehabilitacion, Mexico City, Mexico.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Quintana-Armenta
authors.affiliation: Department of Experimental Surgery, Proyecto Camina A.C., Mexico City, Mexico.
authors.forename: Angelina
authors.initials: A
authors.lastname: Martinez-Cruz
authors.affiliation: Department of Experimental Surgery, Proyecto Camina A.C., Mexico City, Mexico; Research Unit for Neurological Diseases, Instituto Mexicano del Seguro Social, Mexico City, Mexico.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Madrazo
authors.affiliation: Department of Experimental Surgery, Proyecto Camina A.C., Mexico City, Mexico; Research Unit for Neurological Diseases, Instituto Mexicano del Seguro Social, Mexico City, Mexico. Electronic address: guizarg@gmail.com.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Guizar-Sahagun
mesh_terms: D000818:Animals; D049428:Blood-Nerve Barrier / Q000473:pathology*; D015170:Cerebrospinal Fluid Pressure / Q000502:physiology; D003288:Contusions; D004195:Disease Models, Animal; D005260:Female; D051381:Rats; D020318:Rats, Long-Evans; D020127:Recovery of Function; D013116:Spinal Cord / Q000473:pathology*; D013119:Spinal Cord Injuries / Q000473:pathology*; D013346:Subarachnoid Space / Q000473:pathology*
keywords: Blockage; Cerebrospinal fluid flow; Graded contusions; Intrathecal; Patency; Pathophysiology; Self-reparative mechanisms; Spinal cord injury; Subarachnoid space; Superparamagnetic beads