Ix for emergency LP?
All suspected meningitis/encephalitis
Suspected SAH with normal CT
Ix for non-emergency LP?
MS where MRI or clinical signs not conclusive IIH Meningeal seeding neoplasms Carcinomatous/tuberculous meningitis NPH
Contraindications to LP
Raised ICP (clinically or from CT)
Coagulopathy
Anticoag
Local infection
What layers are penetrated in LP?
Skin, s/c tissue, supraspinous ligament,interspinous ligament, ligamentum flavum, dura mater, arachnoid mater