Medical Terminology Simplified

436 CHAPTER 9• Endocrine and Nervous Systems

Nervous System

Laboratory test in which CSF obtained from a lumbar puncture is evaluated macro-

scopically for clarity and color, microscopically for cells, and chemically for proteins

and other substances

CSF analysis helps detect bacteria, viruses, and tumor cells. The analysis also helps

diagnose tumors, infection, or multiple sclerosis (MS).

Diagnostic procedure in which electrodes on the scalp record patterns of electrical

activity within the brain

EEG helps evaluate seizure disorders, periods of unconsciousness, and sleep disorders;

monitors the brain during brain surgery; and determines if a person is in a coma or

brain dead.

Insertion of a needle into the subarachnoid space of the spinal column at the level of the

fourth intervertebral space to withdraw cerebral spinal fluid (CSF) in order to perform

various diagnostic and therapeutic procedures; also called spinal tap or spinal puncture

In lumbar puncture, CSF flows through the needle and is collected and sent to the

laboratory for analysis. Therapeutic procedures include withdrawing CSF to reduce

intracranial pressure, introducing a local anesthetic to induce spinal anesthesia, and

administering intrathecal medications. (See Fig. 9–12.)

Noninvasive functional imaging technique in which magnetic forces associated with

the electrical activity of the brain are recorded externally on the scalp

When the data from an MEG are superimposed on an anatomical image of the brain,

typically an MRI scan, it produces a functional, anatomical image of the brain called

magnetic source imaging (MSI). MSI aids in presurgical evaluation of patients with

epilepsy to identify and localize areas of epileptic activity. MSI results in a high-resolution

image that is a direct measure of brain function.

cerebrospinal fluid (CSF)

analysis

sĕr-ĕ-brō-SPĪ-năl

cerebr/o: cerebrum

spin: spine

-al: pertaining to

electroencephalography

(EEG)

lumbar puncture (LP)

LŬM-băr

lumb: loins (lower

back)

-ar: pertaining to

A

B

L3 vertebra

L4 vertebra

Subarachnoid space containing

cerebrospinal fluid

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Figure 9-12Lumbar puncture. (A)Collection

of cerebrospinal fluid. (B)Position for lumbar

puncture.

magnetoencephalography

(MEG)

măg-nĕt-ō-ĕn-cĕf-ă-

LŎG-ră-fē