Akademik

1. Within a sheath. 2. Within either the subarachnoid or the subdural space.

in·tra·the·cal -'thē-kəl adj introduced into or occurring in the space under the arachnoid membrane of the brain or spinal cord <\intrathecal chemotherapy and cranial irradiation (Jour. Amer. Med. Assoc.)>

in·tra·the·cal·ly -kə-lē adv

1. within the meninges of the spinal cord. An intrathecal injection is made into the meninges.

2. within a sheath, e.g. a nerve sheath.