The central canal of the filum terminale in communicating hydrocephalus.

Lumbar thecoperitoneal shunting was carried out in patients with communicating hydrocephalus due to long-standing tuberculous meningitis. At the time of this surgical procedure, the filum terminale was excised to achieve filum terminostomy. The central canal of the excised filum terminale in seven hydrocephalic children and an equal number from control cases was studied histologically. These observations indicate that the central canal of the filum terminale dilates in communicating hydrocephalus, and the dilatation is proportionate to the lateral ventricular enlargement.