Central Nervous System

1. The brain

2. The spinal cord

The CNS is divided into 2 parts:

Central nervous system

Primary command system

Brain

Composed of an outer portion of gray matter (cortex) and inner portion of white matter

- Forebrain

- Midbrain

- Hindbrain

The brain consists of three parts:

Forebrain

- contains the cerebrum

- largest part of the brain

Midbrain

Stemlike portion that connects the cerebrum to the pons and cerebellum

Hindbrain

Composed of the cerebellum, pons, and medulla oblongata

- Cerebellum

- Pons

- Medulla oblongata

The hindbrain is composed of:

Spinal cord

Consists of an inner, gray, cellular substance and an outer, white, fibrous substance

L1 and L2

The spinal cord extends from the brain to the approximate level of the space between ... and ...

Spinal cord

Is connected to the medulla oblongata at the level of the foramen magnum and ends in a pointed extremity called the conus medullaris

conus medullaris

The spinal cord is connected to the medulla oblongata at the level of the foramen magnum and ends in a pointed extremity called the ...

18-20 in, 31 pairs

In an adult the spinal cord is ... - ... in long and connected to ... pairs of spinal nerves

Cauda equina

Extending portion towards the sacrum, terminal portion of the spinal cord

Meninges

Encloses the brain and spinal cord in three continuous protective membranes

Pia mater

Meninges: Inner sheath

Pia mater

Meninges: highly vascular and closely adherent to the brain

Arachnoid

Meninges: Central sheath

Subarachnoid space

Arachnoid is separated from the Pia mater by a wide space called the ...

Dura mater

Meninges: outer sheath

Cerebrospinal fluid

Contained in the ventricles of the brain and the subarachnoid space

Cerebrospinal fluid

Tissue fluid of the brain and spinal cord

Cerebrospinal fluid

Surrounds and cushions the structures of the CNS

Ventricular system

Contains of four irregular, fluid-containing cavities that communicate with one another

Right and left ventricles

Ventricular system: The two upper cavities are an identical pair called the ...

3rd ventricle

A slitlike cavity with a quadrilateral shape

4th ventricle

Diamond shaped and where the CSF exits to the subarachnoid space

Myelography

Radiographic study of the

spinal cord and its nerve root

branches

Myelography

The spinal cord and nerve roots are outlined by injection of a contrast agent into the subarachnoid space of the spinal canal

- Lesions

- Cancerous or Benign tumors

- Cysts

- Possible bone fragments (in cases of trauma)

Myelography, Clinical indications:

Extent, size, and level

For lesions, Myelography identifies the ..., ..., ...

- Blood in the CSF

- Arachnoiditis

- Increased intracranial pressure

- Recent lumbar puncture

Myelography, Contraindications:

Arachnoiditis

inflammation of the arachnoid membrane

1 hour

Myelography, px preparation:

An injectable sedative or muscle relaxant is usually administered ... before the procedure

injectable sedative or muscle relaxant

Myelography, px preparation:

An ... or ... is usually administered 1 hour before the procedure

Past: Air or gas (Radiolucent), and oil-based iodinated (Radiopaque) CM

Now: Nonionic, water-soluble, iodine-based CM

Myelography, contrast media:

1. Cervical spine

2. Lumbar spine

Needle placement and injection process,

2 locations are used as puncture sites:

Cervical puncture

Patients may be seated in an

erect position or prone , with

the head flexed to open the

interspinous space in C1-C2.

C1 - C2

Cervical puncture:

Patients may be seated in an

erect position or prone , with

the head flexed to open the

interspinous space in ...-...

Lumbar puncture

Patients may be prone

with a firm pillow placed

under the abdomen to

flex the spine or lie in a

left lateral position with

the spine flexed.

Between L3-L4

Lumbar puncture site

Horizontal beam lateral (Transcervical lateral)

• The patient is prone with arms

extended along the side of the

body and shoulder depressed.

• Chin is extended and resting on

a small sponge.

• CR is directed to level C4-C5

• Respiration is suspended.

• The patient is ... with arms

extended along the side of the

body and shoulder ...

• Chin is extended and resting on

a small sponge.

• CR is directed to level ...-...

• Respiration is ...

Horizontal beam lateral (Transcervical lateral):

• The patient is prone with arms

extended along the side of the

body and shoulder depressed.

• Chin is extended and resting on

a small sponge.

• CR is directed to level C4-C5

• Respiration is suspended.

Swimmer's lateral horizontal beam

• The patient is prone with chin

extended.

• For a right lat, the right arm is

extended along the right side of

the body with that shoulder

depressed. The left arm is flexed.

• CR is directed to level C4-C5.

• Respiration is suspended.

• The patient is prone with chin

extended.

• For a right lat, the right arm is

extended along the right side of

the body with that shoulder

depressed. The left arm is flexed.

• CR is directed to level C4-C5.

• Respiration is suspended.

Swimmer's lateral horizontal beam:

• The patient is ... with chin

extended.

• For a ..., the right arm is

extended along the right side of

the body with that shoulder

depressed. The left arm is flexed.

• CR is directed to level ...-...

• Respiration is ...

Right lateral decubitus position (AP or PA projection)

• Position: a true right lateral, with the

right arm flexed superior to the head.

The left arm is extended and rests along

the left side of the body.

• To maintain the alignment of the spine

parallel to the table, rest the patient's

head on a sponge with folded linen.

• CR is directed horizontally at level of T7.

• Respiration is suspended.

• Position: a true right lateral, with the

right arm flexed superior to the head.

The left arm is extended and rests along

the left side of the body.

• To maintain the alignment of the spine

parallel to the table, rest the patient's

head on a sponge with folded linen.

• CR is directed horizontally at level of T7.

• Respiration is suspended.

Right lateral decubitus position (AP or PA projection):

• Position: a ... lateral, with the

... arm flexed superior to the head.

The ... arm is extended and rests along

the ... side of the body.

• To maintain the alignment of the spine

parallel to the table, rest the patient's

head on a sponge with folded linen.

• CR is directed ... at level of ....

• Respiration is ...

Right of left lateral - Vertical beam

• Position: true lateral position,

with knees flexed and both

arms semiflexed.

• Maintain the alignment of the

spine to be parallel to the

table.

• CR is directed at level of T7.

• Respiration is suspended.

• Position: true lateral position,

with knees flexed and both

arms semiflexed.

• Maintain the alignment of the

spine to be parallel to the

table.

• CR is directed at level of T7.

• Respiration is suspended.

Right of left lateral - Vertical beam

• Position: ... position,

with knees ... and both

arms ...

• Maintain the alignment of the

spine to be ... to the

table.

• CR is directed at level of ...

• Respiration is ...

Semierect lateral - Horizontal beam

• The patient is prone with arms

flexed superior to the head.

• The table is adjusted to a

semierect position.

• CR is directed horizontally at

level of L3.

• Respiration is suspended.

• The patient is prone with arms

flexed superior to the head.

• The table is adjusted to a

semierect position.

• CR is directed horizontally at

level of L3.

• Respiration is suspended.

Semierect lateral - Horizontal beam

• The patient is ... with arms

flexed superior to the head.

• The table is adjusted to a

semierect position.

• CR is directed ... at level of ...

• Respiration is ...

Ventriculography

Radiologic demonstration of the cerebral ventricular system by direct injection of air into the ventricles.

Discography

Radiographic examination

of the intervertebral disc

following injection of

contrast medium.

Discography

Usually performed in the

lumbo-sacral region

compared to the cervical

region.

lumbo-sacral region

Discography is usually performed in the ...

compared to the cervical region.

Disc herniation or degeneration

Discography, Indications:

Disc herniation or degeneration

Happens when soft like jelly in the intervertebral disc pushes out of a tear and presses in to a nerve

• Patient must have a recent radiographic

examination of the spine.

• NPO for 5 hours

Discography, px preparation:

10mg of Droperidol and 0.15 mg Phenoperidine

Discography, premedication:

0.5 - 2 ml of Meglumine Iothalamate or

Meglumine Diatrizoate

Discography, contrast media:

Lateral decubitus position

Position for discography

18 - 20 Gauge needle

Introducer needle gauge

22 or 25 gauge needle

Discogram needle gauge

Radiculography

Radiographic examination of the cauda

equine, lumbar and sacral nerves following

the injection of water-soluble CM into the

lumbar subarachnoid space

• Patient must have recent radiographic

examination of the spine.

• NPO for 5 hours

• Empty bladder

Radiculography, px preparation:

Meglumine locarmate (Dimer X) not more than 5 ml

Radiculography, CM:

Pneumoencephalography (Air encephalography)

Radiologic

demonstration of the

cerebral ventricular

system using air as CM.

• Intra-cranial space occupying lesions

• Investigation of cerebral atrophy

• Hydrocephalus

Pneumoencephalography (Air encephalography), Indications:

Intra-cranial space occupying lesions

Any abnormal mass such as tumor abscess or blood clot that grows inside the skull and takes up room meant for normal brain tissue

Cerebral atrophy

Loss of brain cells and the connection between them leading to the shrinking of brain tissue

• Routine views of skull and chest

• NPO for 5 hours

• Empty bladder

Pneumoencephalography (Air encephalography), Patient preparation:

Nembutal or Omnopon

Pneumoencephalography (Air encephalography), premedication:

20 - 30 ml of air

Pneumoencephalography (Air encephalography), contrast media:

1. Maxwell Pneumothorax Machine

2. Automatic Gas Dispenser

Pneumoencephalography (Air encephalography),

Methods of introducing air:

Sparkle cylinder of carbon dioxide

Maxwell Pneumothorax Machine

Automatic Gas Dispenser

Slow steady infusion of aid

Hanging head lateral projection

Patient head is hanged so that the air moves up

• Take AP, Lateral and Townes Projection

• Hanging Head lateral Projection

• OML is parallel to table

• CR is directed horizontally at the level of 2 in above EAM.

Pneumoencephalography (Air encephalography), Procedure:

Pneumoencephalography (Air encephalography)

Best demonstrates air in the anterior part of the 3rd ventricle