Facts on File Encyclopedia of Health and Medicine

sign language A nonverbal language that serves
as a system of communication for people who are
hearing impaired. Sign language uses hand signals
to represent letters of the alphabet and gestures to
represent words, phrases, and concepts. As in spo-
ken languages, sign languages incorporate an
extensive vocabulary with rules that govern its
presentation (grammar and syntax). The sign lan-
guages most used in the United States are

• American Sign Language (ASL) derives its
  structure from French Sign Language, which
  was the first formal sign language, and is a
  unique language separate from spoken English.
  ASL is the third most common language in the
  United States.


• Signing Exact English (SEE) evolved in the
  early 1970s as a method to manually code spo-
  ken English for children learning to read and
  for people without hearing impairment who
  communicate with those who have hearing
  impairment.


• Pidgin Signed English (PSE) blends aspects of
  ASL and SEE for colloquial or casual communi-
  cation.

Though sign languages may carry a culture’s
name, such as American Sign Language or Japan-
ese Sign Language, there is no correlation
between the sign language and the culture’s spo-
ken language. Nor are sign languages necessarily
similar to each other.
The BRAINprocesses sign languages differently
from spoken languages. Because spoken languages
form the basis for reading and writing, prelingual
children who have profound HEARING LOSSmay
easily learn a sign language and yet have difficulty
learning to read and write.
See also BRAILLE; COGNITIVE FUNCTION AND DYS-
FUNCTION.

sinuses Cavities within the facial bones around
the NOSE, also called the paranasal sinuses, that
warm and moisten inhaled air. Mucous membrane
lines the sinuses, providing a continuous supply of
moisture. Mucus production increases in response
to irritation, for example, from environmental
particles (pollen, smoke), viruses, and BACTERIA.
The maxillary sinuses, on the face along the ridge

of BONEcommonly called the cheek bone, and the

frontal sinuses, above the inside corners of the

eyes near the bridge of the nose, are the sinuses

that most commonly become congested as a result

of COLDS, allergies, and infections. The sinuses also

function as sound chambers that give the voice

resonance and amplification. Sinus congestion

limits this function, resulting in a characteristic

“nasal” voice.

For further discussion of the sinuses within the

context of otolaryngologic structure and function

please see the overview section “The Ear, Nose,

Mouth, and Throat.”

See also ALLERGIC RHINITIS; NASAL POLYP; SINUSITIS.

sinusitis INFLAMMATIONof the SINUSES. The most

common causes of sinusitis are INFECTIONand envi-

ronmental irritation such as seasonal allergies

(ALLERGIC RHINITIS). Sinusitis affects an estimated 37

million Americans each year. It can be acute (lasts

a few weeks), chronic (lasts months to years), or

recurrent (occurs in repeated acute episodes).

Doctors further define chronic sinusitis by the

extent of permanent damage to the mucous lining

of the nasal passages. Long-term chronic sinusitis

causes narrowing of the openings through which

mucus drains out of the sinuses.

Symptoms and Diagnostic Path

The symptoms of sinusitis include

• PAINacross the cheek bones or between the
  eyes


• pain in the upper jaw and TEETH
  
  
  • persistent HEADACHEthat is worst on awakening
    in the morning and improves through the day
    though does not entirely go away
  
  
  
  


• nasal congestion


• frequent sneezing


• thick, colored discharge from the nostrils


• POSTNASAL DRIP

Some people with sinusitis also have FEVER,

COUGH, and PHARYNGITIS(from the postnasal drip).

The diagnostic path includes careful examination

of the inside of the NOSE. For acute sinusitis the

doctor may make the diagnosis on the basis of

what he or she observes. Doctors seldom order

sinusitis 51