ST 240

 Central nervous system (CNS) – the brain and the spinal cord
 Peripheral nervous system (PNS) – external to the brain and spinal cord from their roots to their peripheral terminations.
This includes any plexuses through which the nerve fibers run.

 Spinal nerves - 31 pairs of nerves which carry (send) messages to & from the spinal cord

Spinal Nerve Plexus & Important Nerves

 Any membrane; specifically, one of the membranous coverings of the brain and spinal cord.
 Dura matera tough, fibrous membrane forming the outer covering
 Arachnoidea - A delicate fibrous membrane forming the middle. In life, its smooth external surface is closely applied
(but not attached) to the internal surface of the dura mater, with only a potential space ( subdural space ) intervening.
Between the Arachnoidea and Pia mater is Subarachnoid space
 Pia mater - A delicate vasculated fibrous membrane firmly adherent to the capsule of the brain
 Lumbar puncture -needle puncture made into the subarachnoid space; usually between 3&4 or 4&5 lumbar vertebrae performed for various reasons

 To remove pathological lesions
 To relieve pressure on brain or spinal cord due to disease or injury
 To relieve pain
 To relieve injured or diseased peripheral nerves
 To treat congenital anomalies

 Carpal tunnel release - decompression of the medial nerve
 Carpal tunnel syndrome -painful disorder of the wrist & hand in which pressure is on the median nerve at the point at which it goes through the carpal tunnel
 Cranial nerve - 12 pairs of nerves which carry messages to & from the brain

Ventricle -one of the cavities of the brain; produces CSF
 Cerebrospinal fluid
(CSF) -watery fluid protecting the brain & spinal cord

 Automatic nerves -that part of the nervous system which represents the motor innervation of smooth muscle, cardiac muscle, and gland cells. It consists of two mutually antagonistic components: the sympathetic and parasympathetic parts
 A-V malformations -thin-walled vascular channels that connect arteries and veins without the usual intervening capillaries; may give rise to intracerebral hemorrhage
 Brain abscess -localized collection of pus in the intracranial region

 Craniosynostosis -premature ossification of the sutures of the skull
 Decompression -the removal of pressure
 Stereotaxis -accurate placement of a probe, needle or electrode in a specific location in the brain

 Digitalized angiography – (Cerebral angiography) - x-ray are taken after injection of a contrast medium into the intracranial vessels, helps visualize aneurysms, tumors, or other vascular lesions
 Echoencephalography -ultrasonic waves used to detect brain tumors; used to detect brain tumors, hematomas, swelling or abscesses
 Pneumoncephalography -air is injected through a lumbar puncture into a subarachnoid space & x-rays are taken to reveal the outline of the ventricular system

 Pericranium -fibrous membrane surrounding the cranium; periosteum of the skull
 Peripheral nerves – nerves which connect the brain or spinal cord with peripheral receptors or effectors
 Sella turcia -a concavity in the superior surface of the body of the sphenoid bone which houses the pituitary gland

 Pituitary tumor -benign or malignant tumor that presses on the optic chiasm & impairs vision & may cause symptoms of acromegaly
 Meningocele -congenital hernia with the meninges protruding through opening of the skull or spinal column
 Sciatica pain -severe pain in the leg along the course of the sciatic nerve felt at back of thigh running down the inside of the leg

Mechanical methods of hemostasis
 Bone wax
 Scalp clips
 Cottonoids ½” to 2x3
 Monopolar and/or bipolar electrocoagulation
 Ligaclips

 Oxycel
 Topical thrombin
 Gelfoam
 Surgicel
 Avitene

Special considerations of neurosurgical procedures
 If the patient’s hair is shaved, it is considered part of patient’s personal belongings, bagged & set back to room with patient.
 Surgeon may assist with draping
 Surgical technologist keeps rongeur clean for continued use.

Craniotomy -incision into the cranium to treat intracranial disorders

Pin Fixation Device Headrests -used to securely position or fixate the skull during a cranial or cervical spine operation

 Surgeon places scalp clips for hemostasis along the outside edge of the incision.
 Scalp flap is turned back & covered with a moist sponge & sterile towel.
 Surgeon strips peritoseum from the bone with periosteal elevator

 Surgeon makes 2 or more bur holes with either a hand-or-power drill (ANSPACH drill with perforator)
 Technologist must be ready to irrigate the drilling site to counteract heat buildup
& to remove bone dust.
 Surgeon saws skull bone between bur holes with cranial tome

 Surgeon separates the dura mater from the bone by a dura separator (Penfield
#3 dissector)
 Surgeon uses rongeur, such as a
Kerrison, to enlarge the bur holes.
 Have bone wax ready

#1 #2 #3
#4

Surgeon lifts the skull flap off the dura mater with 2 periosteal elevators & controls bleeding with bone wax.
 Skull flap is covered with moist sponge and a sterile towel
& protected in saline moistened sponges into a basin. (bug juice: saline & antibiotic solution)

Dura Opened and Retracted/Cerebellar Hemispheres
Exposed
 Surgeon grasps dura edges extends the incision with
Metzenbaum scissors.
 At this point, technologist needs to prepare traction sutures on fine needle holders
(dolphin head) Ryder needleholders)
 Surgeon protects brain surface with moist cottonoid strips.

 Surgeon closes dura mater with fine absorbable suture.(4-0 nylon P3 popup)
(possibly 3 pkgs of 8 or more)
 Skull flap is replaced and fixated with plates and screws
 Surgeon removes scalp clips & sutures muscle (Vicryl 2-0 or 0 CT2 or 3 or UR6, subcutaneous tissue), skin - sutures of choice (usu. staples)

 Cranioplasty -repair of a skull defect resulting from trauma, malformation, Or a surgical procedure; involves covering the defect with some type of prosthetic material, such as metal, methyl methacrylate, silicone rubber, or bone & cartilage
 If tumor has grown into bone, cranioplasty is done

 Bur holes (trephination) -Removal of a circular piece (“button”) of cranium
 Remove a collection of fluid beneath the dura mater
 Tap a ventricle to relieve pressure
 Aspirate a brain abscess & instill antibiotics
 Locate & drain a subdural hematoma

 Craniectomy incision into the skull
& removal of bone

 Hematoma -tumor or swelling that contains blood

 Intracranial aneurysm localized abnormal dilation of a blood vessel in the skull may be due to a congenital defect or weakness of the wall of vessel

Aneurysm Clips -device placed on an aneurysm to prevent hemorrhage yet allow collateral blood flow
Permanent Clip
Temporary Clip
Clip Applier

Ventriculoatrial Shunt: Hydrocephalus
 Hydrocephalus -increase accumulation of cerebrospinal fluid within the ventricles of the brain resulting from an interference with the normal circulation & absorption of the fluid
 Shunt operations -performed to treat hydrocephalus by diverting excessive cerebrospinal fluid from cerebral ventricles to other body cavities where the fluid can be absorbed

Ventriculoperitoneal Shunt
VP shunt : Hydrocephalus

Ventriculoatrial Shunt: Hydrocephalus

Nucleus pulposus - the center cushioning of gelatinous mass lying within an intervertebral disc (or disk)

 Intractable pain pain that cannot be easily relieved, such, as that occurring from certain neuro plastic invasions EX: herniated disc, lamina expansion)

 Laminectomy -removal of one or more vertebral laminae to expose spinal cord; commonly performed to treat one of the following:
 herniated disc (nucleus pulposus)
 spinal cord tumor
 meningocele
 compression fracture or dislocation
 spinal cord injuries due to trauma
 Lamina -the flattened part of either side of the arch of a vertebra

Lumbar Myelogram with Herniated Disk
(degeneration)
 Myleography -contrast medium is injected into the subarachnoid space of the spinal canal to visual a herniated disc, tumor, or other abnormality
 Herniated disc - rupture of the fibrocartilage surrounding an invertebral disc, releasing the nucleus pulposus that cushions the vertebrae above
& below with resulting pressure on the spinal nerve roots & pain

Posterior lumbar discectomy with interbody fusionPLIF
 Excision of one or more herniated lumbar intervertebral discs & the placement of bone grafts between the vertebrae to fuse them together; internal fixation can be implanted; lateral fusion may also be done (
Laminectomy must be done )

Anterior lumbar discectomy with interbody fusion ALIF
 Anterior excision of one or more herniated lumbar intervertebral discs & the placement of bone grafts between the vertebrae to fuse them together; internal fixation can be implanted posteriorly; lateral fusion may also be done

Removal of anterior cervical disc with fusion – ACD,ACF Excision of one or more herniated cervical intervertebral discs & the placement of bone grafts between the vertebrae to fuse them together
.

 An anterior cervical fusion involves 2 operative sites.
 Both operative sites, the neck & iliac crest are prepped & draped. Thyroid drapes at neck folded up above hip.
Lower half of body also draped.
 The bone graft commonly taken from iliac crest
 Surgeon removes disc with pituitary ronguer & fine curettes.