It doesn’t seem likely that a spinal liquid punition can cause disk herniation because the needle during the procedure reaches only the subarachnoidal space and does not touch the intervertebral disks. To cause a disk herniation, a needle would have to pass through the spinal nerves roots (cauda equine), posterior longitudinal ligament and rupture the disk’s fibrous annulus.
It is not clear from your question why doctors performed the liqiod punition and how they identified a “cerebral pseudotumor”. Liquid punitions are performed to confirm possible infections (meningitis) or subarachnoidal hemorrhages. A non-invasive diagnostic procedures like an MRI or CT-scan should be done first. Brain tumors or hemorrhage can be seen on CT-scan or MRI. Infection (meningitis or encephalitis) can be proven only via liquid punition.
Disk herniations can be treated only surgically and you may consult a neurosurgeon or an orthopedist about the treatment.