Can cervical spinal stenosis which causes the thecal sac to be fully compressed around cord cause hydrocephalus?

No, cervical spinal stenosis which causes the thecal sac to be fully compressed around the cord will not typically cause hydrocephalus.

Hydrocephalus is a condition characterized by an abnormal accumulation of cerebrospinal fluid (CSF) within the ventricles of the brain, leading to increased pressure inside the skull. It is commonly caused by blockages or obstructions that disrupt the normal flow and absorption of CSF.

Cervical spinal stenosis, on the other hand, refers to the narrowing of the spinal canal in the cervical (neck) region, resulting in compression of the spinal cord and nerve roots. While compression at this level can cause a variety of neurological symptoms, it does not directly impact the production or flow of CSF within the ventricles of the brain.

Therefore, cervical spinal stenosis is not typically associated with the development of hydrocephalus.