Terms / Definitions with an overview of

Arnold  Chiari (“ kee  ar  E” ) Malformation


Information compiled by: Lisa Struss, Speech Pathology Graduate Student,

Herbert H. Lehman College, City University of New York, August 2001.



Achalasia:  A rare disease of the esophagus with abnormal function of nerves and muscles of the esophagus causes difficulty swallowing and sometimes chest pain.  Regurgitation of undigested food can occur, as can cough or breathing problems related to entry of food material into the lungs.  The underlying problem is weakness of the lower portion of the esophagus and failure of the lowest most portion to open and allow passage of food.  It is the failure of the lower sphincter muscle of the esophagus to relax. 



Anencephaly:   A Neural Tube Defect (NTD) that occurs when the cephalic (head) end of the neural tube fails to close, usually between 23rd and 26th days of pregnancy, resulting in the absence of a major portion of the brain, skull and scalp.  Infants with this disorder are born without a forebrain consisting mainly of the cerebrum, which is responsible for thinking and coordination.  The remaining brain tissue is often exposed; it is not covered by bone or skin.  Infants born with anencephaly are usually blind, deaf and unconscious (interruption of awareness of oneself and one’s surroundings.  Lack of the ability to notice or respond to stimuli in the environment).  Although some individuals with anencephaly may be born with a rudimentary brain stem, the lack of a functioning cerebrum permanently rules out the possibility of ever gaining consciousness.  Reflex actions such as respiration (breathing) and responses to tough or sound may occur.  The disorder is one of the most common disorder of the fetal central nervous system.  Approximately 1,000 to 2,000 babies are born with anencephaly each year in the United States.  The disorder affects females more often than males.  There is no cure or effective treatment for anencephaly and the outlook for affected individuals is very poor.  Most infants with anencephaly do not survive infancy.  If the infant is not still born, he/she will usually die within a few hours or days after birth. 



Aplasia:  Failure to develop.



Apnea:   (Greek “Apnea” meaning “Want of breath”) The absence of breathing.  There are three types or forms of apnea: blockage of the airways, cessation of respiratory effort (usually brain related and referred to as “central”) and a combination of airway blockage and central apnea.  Central apnea is characterized by brief interruptions of breathing during sleep. Occurs when brain fails to send the appropriate signals to the breathing

muscles to initiate respiration. Obstructive sleep apnea is much more common than central apnea.  Obstructive occurs when air cannot flow in or out of a person’s nose or mouth, although efforts to breath continue.  The throat collapses during sleep causing the individual to snort and gasp for breath.  Hundreds of these episodes can occur every night  causing daytime sleepiness and it is thought increasing the risk of hypertension (high blood pressure) and heart problems.  Disorder of breathing during sleep.  It usually occurs in association with fat build up or loss of muscle tone with aging.  These changes allow the windpipe to collapse during breathing when muscles relax during sleep.  It also occurs if the neurons that control breathing malfunction during sleep.



Arachnoiditis:  Inflammation of the middle layers of the membranes covering the brain and spinal cord. 



Arrhythmia : Abnormal heart rhythm.  In arrhythmia the heartbeats may be too slow, too rapid, too irregular or too early.  Rapid arrhythmias (greater than 100 beats per minute) are called tachycardias.  Slow arrhythmias (slower than 60 beats per minute) are called bradycardias.  Irregular heart rhythms are called fibrillations (as in atrial fibrillation and ventricular fibrillation).  When a single heartbeat occurs earlier than normal, it is called a premature contraction. 



Articulation:  Vocal tract movements for speech sound production; involves accuracy in placement of the articulators, timing, direction of movements, force extended, speed of response and neural integration of all vents.



Articulators:  Organs of the speech mechanism which are involved in the production of speech:  a. cheeks, alveolar ridge, teeth, lips, lower jaw, velum, tongue, and pharynx which serve to interrupt or modify the voiced or unvoiced air stream into meaningful sounds. b. larynx, which creates sound energy (phonation), c. resonators, cavities (pharyngeal, laryngeal, oral and nasal) whose changes in size and shape alter the fundamental vibrations produced by the vocal folds, d.  respiratory system (lungs and air passages), which furnishes the air necessary for the production of sounds.



Aspiration:  Accidental sucking in of food particles or fluids into the lungs. 



Ataxia:  Wobbliness.  Ataxia is lack of coordination and unsteadiness due to the brain’s failure to regulate the body’s posture and regulate the strength and direction of limb movements.  Ataxia is usually a consequence of disease in the brain, specifically in the cerebellum,

which lies beneath the back part of the cerebrum. Other symptoms can include a lack of balance, slurred speech, lack of muscle control, drooling and swallowing difficulties.



ADHD (Attention Deficit Hyperactive Disorder): ADHD is a condition that refers to individuals inability to control their own behavior or impulses.  It can be manifested as constant movement and fidgeting.  These individuals have difficulty blocking out noise or other stimuli in order to focus on a task or what is being said.  It is a chronic problem that can be seen as early as infancy and can extend into adulthood.  There are two types of Attention Deficit Disorder.  The most obvious is ADHD.  The primary characteristic is hyperactivity, which is first seen before a child even enters school.  The less obvious type is ADD, where hyperactivity is NOT present.  The primary characteristic of this type is inattentiveness. 



Bilateral:  Pertaining to two sides. 



Birth Defect:  A birth defect is a physical abnormality that is present at the time of the birth of a child.  Birth defects can include many different organs including the brain, heart, lungs, liver, bones and intestinal tract.  How a birth defect affects a given child will vary and depends greatly on the severity of the defect and whether or not other medical conditions are present.   



Brainstem: It is the stem like part of the brain that is connected to the spinal cord, or conversely, the extension of the spinal cord up into the brain.  The brain stem is small but important.  It manages going between the brain and the rest of the body and it also controls basic body functions such as breathing, swallowing, heart rate and blood pressure.  The brain stem also controls consciousness and determines whether someone is awake or sleepy. The brain stem is also associated with most of the special senses (vision and hearing in particular), and it controls muscular activity in the head and part of the neck.  The brainstem consists of the midbrain, pons, and medulla oblongata.   

To see a picture:   www.waiting.com/brainstem.html#anchor580032



Cardio Vascular System: Is the circulatory system, which is comprised of the heart, lungs and blood vessels.   



Central Nervous System: Also known as CNS: consists of two major parts: the brain, which is the center of neural integration, and the spinal cord, which contains billions of

neurons that run to and from the brain and also mediates many of the body’s reflex responses. The CNS is covered by three meninges (singular : meninx), composed of connective tissue.  In order, from outside in, we have the dura mater, pia mater and the  arachnoid membrane.  The CNS is bathed in cerebrospinal fluid.  The CNS functions in body orientation and coordination, assimilation of experiences, and programming of instructional behavior. The nervous system is the body of tissue that records and distributes information in the body using electrical and chemical transmission.  It has two

parts.  The “central” nervous system is comprised of the brain and spinal cord.  The “peripheral” nervous system is the nerve tissue that transmits sensation and motor information back and forth from the body to the central nervous system.

See CNS nerves at: www.publish.uwo.ca/~jkiernan/wholens.jpg


Cerebellar Tonsils: 1. Two appendages of the brain at the base of the cerebellum.

2.      They are rounded areas on the undersurface of each cerebellar hemisphere.  


Cerebellum:  It is an important integrating center for coordinated regulation of limb movement, balance and structure.  ’s function is for balance and coordination.  It is that portion of the brain located at the posterior base of the cranial cavity beneath the occipital and temporal lobes of the cerebrum.  It is attached to the medulla, pons, and midbrain of the brainstem by three pairs of tracts, which connect it with the cerebrum, brainstem, and spinal cord and enable it to coordinate body motor function initiated by the cerebrum and to maintain muscle tone and equilibrium.

To see a picture: www.com/brainfuncthree.html





Cerebral:  Of or pertaining to the brain or skull cavity. 



Cerebral Hemisphere:  The two halves of the cerebrum.



Cerebral Spine:  Bones in the upper neck. There are seven of them (C1-C7)



Cerebrum:  The largest part of the brain.  It is divided into two hemispheres or halves.  The word cerebrum is the Latin word for “brain.”  The Romans used the same word to refer to the “skull,” (which houses the brain) and the “head” (which houses the skull) And in Rome, “cerebrum” also meant, “understanding” (and a fiery temper).  The word “cerebrate” meaning “to use the mind, or think,” comes from the Latin, “cerebrum.”



Cerebrospinal fluid also known as CSF: Protein rich liquid, which cushions and nourishes the brain.  This fluid also surrounds the delicate brain and spinal cord, cushioning it against injury. 



Cerebrum:  It controls most sensory and motor activities; reasoning, memory, intelligence, etc. instinctual and limbic (emotional) functions. It is usually associated with higher brain functioning, such as speech and rational thought.  It is the largest portion of the brain, consisting of paired right and left hemispheres united by the corpus callosum beneath the longitudinal fissure.



Cervical Spine: The neck region of the spinal column (the cervical spine) consists of seven bones vertebrae) shaped like building blocks, which are separated from one another by shock absorbency pads (intervertebral discs). 



CNS:  See above:  Central Nervous System



Comprehension:  Knowledge or understanding of an object, situation, event or verbal statement.  In speech, it is the understanding of spoken utterances, as distinguished from producing utterances. 



Congenital: Acquired at birth or during uterine development as a result of hereditary or environmental influences.



Corpus Callosum: A prominent band of fibers that unites the two hemispheres of the brain.



Cranial Nerves: There are twelve pairs of cranial nerves that are usually recognized and are referred to by Roman numerals and by names.  They are numbered according to their emergence from the brain stem.  The names of the cranial nerves reflect function.  They merge from the central stalk of the human brain, and 31 pairs of spinal nerves extend from the spinal cord out between the vertebrae of humans.  For the most part the cranial nerves supply nerves to tissues and organs of the head and neck, where as the spinal nerves innervates the chest, abdomen and limbs. See: 







Cyanotic (cyanosis): A bluish discoloration of the skin (includes nail beds, feet, nose, ears, lips, fingers, toes) or mucous membranes caused by a lack of oxygen in the blood.



Diplopia:  Diplopia is a condition whereby a single object appears as two objects.  Also called, “double vision.”



Dizziness:  A medically indistinct term, which is used to describe a variety of conditions, including lightheadedness, near loss of consciousness, unsteadiness and vertigo. 



Dysphagia: Injury or disease almost anywhere in the head and neck can lead to dysphagia.  Dysphagia is difficulty in swallowing due to problems in muscle control; may include inflammation, compression, paralysis, weakness, or hypertonicity of the esophagus.    Dysphagia comes from the Greek word phagein meaning to eat.  Dysphagia can occur anywhere along the path from the lips to the stomach.  Speech Language Pathologists are primarily concerned about problems in the oral cavity,   

pharynx, or larynx.  Similarly, gastroenterologists (physicians who diagnose and treat disorders of the esophagus, stomach and intestinal tract) also use the term dysphagia when referring to esophageal dysphagia.



Dysphonia:  Dysphonia is a voice disorder also called dystonia caused by involuntary movements of one or more muscles of the larynx or voice box.  People who have spasmodic dysphonia may have occasional difficulty saying a word or two or they may experience sufficient difficulty to interfere with communication.  Spasmodic dysphonia causes the voice to break or to have a tight, strained or strangled quality.  There are three different types of spasmodic dysphonia: adductor spasmodic dysphonia, abductor spasmodic dysphonia and mixed spasmodic dysphonia.


Adductor spasmodic dysphonia: Here sudden involuntary muscle movements or spasms cause the vocal folds/cords to slam together (adduct) and stiffen.  These spasms make it difficult for the vocal folds /cords to vibrate and produce voice.  Words are often cut off or difficult to start because of the muscle spasms.  Therefore speech may be choppy and sound similar to stuttering.  The voice of an individual with adductor spasmodic dysphonia is commonly described as strained or strangled and full of effort.  Surprising the spasms are usually absent while whispering, laughing, singing, speaking at a high pitch or speaking while breathing in.  Stress, however, often makes the muscle spasms more severe.   


Abductor spasmodic dysphonia: In abductor spasmodic dysphonia, sudden involuntary muscle movements or spasms cause the vocal folds/cords to open (abduct).  The vocal folds/cords cannot vibrate when they are open.  The open position of the vocal folds/cords also allows air to escape from the lungs during speech.  As a result, the voices of these individuals often sound weak, quiet and breathy or whispery.  As with adductor spasmodic dysphonia, the spasms are often absent during activities such as singing or laughing.


Mixed spasmodic dysphonia: Mixed spasmodic dysphonia involves muscles that open the vocal folds/cords as well as muscles that close the vocal folds/cords and therefore has features of both adductor and abductor spasmodic dysphonia.



Encephalocele:  Portion of the brain protruding out from the occipital region in a skin-covered sac.



Esophageal:  Relating to the esophagus. 



Esophagus:  Is part of the digestive tract.  It is a tube that connects the throat with the stomach.  It lies between the trachea (windpipe) and the spine.  In an adult the esophagus is about 10 inches long.  When a persons swallows, the muscular walls of the esophagus contract to push food down into the stomach.  Glands in the lining of the esophagus produce mucous, which keeps passageway moist and makes swallowing easier. It is supplied by the vagus (X cranial nerve) nerve.



Esophageal Reflux: conditions where in the stomach contents regurgitate, or back up (reflux) into the esophagus. (a long cylindrical tube that transports food from the mouth to the stomach).  The food is partially digested by stomach acids content refluxes backwards up into the esophagus, occasionally reaching the breathing passages, causing inflammation and damage to the esophagus, as well as to the lung and larynx (voice box).  The process is medically termed Gastro Esophageal Reflux Disease (GERD).  GERD can lead to scarring and stricture of the esophagus, requiring stretching (dialating) of the esophagus.  10% of patients with GERD develop Barrett’s esophagus, which can increase the risk of cancer of the esophagus. 80% of patients with GERD also have a hiatal hernia.



Folic Acid: One of the B vitamins that is a key factor in the making of nucleic acid (DNA and RNA) 


Foramen:  A natural opening, a hole particularly through a bone.


Foramen Magnum: A large hole at the base of the skull, which allows passage of the spinal cord. 

To see a picture: www.teaching-biomed.man.ac.uk/student_projects/2001/mnbf8ao2/enlarged/accessory%20foramen%20magnum.htm





Fossa:  A pit or hollow.



Gastroesophageal Reflux: See esophageal reflux.



Hemisphere:  Half of a spherical structure; usually used in reference to brain structures. 



Hernia /Herniation: Protrusion of an organ or other bodily structure through the wall that normally contains it; a rupture.



Hindbrain (rhombencephalon):   A term that describes it’s shape (Greek rhombos), a spinning top.    It is divided into a metencephalon (Greek meta, after + enkephalos, brain) and a myelencephalon (Greek myelos, marrow).  In the adult the myelencephalon, an enlarged region where the spinal cord merges into the brain, is called the medulla oblongata.   The fluid filled central canal of the spinal cord also enlarges in the hindbrain, where it is known as the fourth ventricle. 

            The upper portion of the hindbrain is called the metencephalon.  The prominent dorsal region of the metencephalon is formed by the cerebellum (little brain), while ventrally the metencephalon is an upward continuation of the medulla oblongata called the pons.  


Hydrocephalus:  Greek “hydro”/ water and cephalus / brain.    Hydrocephalus is an abnormal accumulation of Cerebral Spinal Fluid (CSF) in the brain.  The CSF is often under increased pressure and compresses (squeeze) and damages the brain.  Hydrocephalus is a condition that can arise before birth or at anytime afterward and so it can be congenital or acquired.  It can be due to many causes including birth defect, hemorrhage into the brain, infection, disease, meningitis, stroke, tumor or head injury.  Most forms of hydrocephalus are the result of an obstructed flow of CSF in the ventricles (normal cavities in the center of the brain).  With birth defects the physical obstruction of the CSF flow through the ventricles is usually the cause of hydrocephalus.


Hydrocephalus is a common companion of a birth defect called spina bifida (also known

as meningomyelocele).  The most obvious signs and symptoms of hydrocephalus in infants is usually an abnormally large head.  This occurs because of the constant outward pressure on the brain and the skull from the fluid during the development and growth of the head (that is one reason a baby’s head should be measured at every well-baby visit).  Other symptoms in infants may include; vomiting, sleepiness, irritability, an inability to look upwards and seizures. 

In older children and adults there is no head enlargement form the hydrocephalus (because the skull bones are all fused together and cannot permit enlargement) Symptoms may include; headache, nausea, vomiting and sometimes blurred vision.  There may be problems with balance and coordination and delayed development in walking and talking in young children.  Irritability, fatigue, seizures and personality changes such as an  inability to concentrate or remember things may also develop.  Drowsiness and double vision are common symptom of hydrocephalus progresses.



Hydromyelia:  An abnormal enlargement of the central canal of the spinal canal with an abnormal accumulation of fluid.



Hypoplasia:  Underdevelopment or incomplete development of a tissue or organ.  For example there can be hypoplasia (underdevelopment) of the enamel of the teeth.  Hypoplasia is less drastic than aplasia where there is no development at all. 



Laryngeal:  See Larynx. 



Larynx: also known as the “voice box  The larynx is the primary organ of phonation.  The larynx is the portion of the breathing or respiratory tract contains the vocal cords  that produces vocal sound.  It is located between the pharynx and the trachea.  The larynx also called the “voice box” is a 2 inch long, tube shaped organ in the neck.  We use the larynx when we breathe, talk or swallow.  Its outer wall of cartilage forms the area of the neck referred to as the “Adams Apple.” The vocal cords/folds are two bands of muscle that form a “V” inside the larynx.  Each time we breathe in air goes into our nose or mouth, then through the larynx, down the trachea and into our lungs.  When we breathe out, the air goes the other way.  When we breath the vocal cords/folds are relaxed and the air moves through the space between them without making any sound.  When we talk the vocal cords/folds tighten up and move closer together.  Air from the lungs is  forced between the vocal cords/folds and makes them vibrate, producing the sound of our voice.  The tongue, lips and teeth for this sound into our words.  The esophagus, a tube that carries food from the mouth to the stomach is just behind the trachea and the larynx.  The opening of the esophagus and the larynx are very close together in the throat.  When we swallow, a flap called the epiglottis moves down over the larynx to keep food out of the windpipe (trachea).




Lethargy:  Abnormal drowsiness, stupor. 



Malformation:  A physical defect present at birth.



Medulla Oblongata (Myelencephalon) :  It is the base of the brain, which is formed by the enlarged top of the spinal cord.  This part of the brain directly controls breathing, blood flow and other essential functions. (E.g., respiration, heart rate, vasoconstriction).

To see a picture: www.waiting.com/brainstem.html#anchor543500



To see a picture: www.com/brainfuncthree.html



  Meninges (singular: meninx): The Central Nervous System (CNS) is covered by three meninges (singular is meninx), composed of connective tissue.  In order, from outside in, we have the dura mater (the most resilient of the three), the arachnoid membrane, and the pia mater.

To see a picture: 




Meningomyelocele see spina bifida: Meningomyelocele is protrusion of the membranes that cover the spine but some of the spinal cord itself through a defect in the bony encasement of the vertebral column.  The bony defect is spina bifida. 



Meningeal membranes: See Meninges



Metencephalon:  Upper portion of the hindbrain.  See hindbrain. 



Midbrain (mesencephalon): connecting the diencephalons and pons is a short narrow pillar containing a center for visual reflexes.

To see a picture: www.com/brainfuncthree.html



Myelencephalon:  See medulla oblongata.



Myelodysplasia (MDS): Disease of the bone marrow and blood platelets.  Patients with MDS - the bone marrow produces too few red blood cells, white blood cells and platelets.  Common symptom is anemia.



Nerve:  A bundle of fibers that uses electrical and chemical signals to transmit sensory and motor information from one body part to another. 



Nervous System:   See Central Nervous System.



Nuclei:  nerve cells



Neural Tube Defect (NTD): NTD is a birth defect caused by abnormal development of the neural tube.  (Neural Tube is the structure present during embryonic life, which gives

rise to the central nervous system – to the brain and spinal cord.  The best known neural tube defects are anencephaly (absence of the cranial vault and absence of most or all of the cerebral hemispheres of the brain), and spina bifida (an opening in the vertebral column protecting the spinal cord), sometimes with a meningomyelocele (protrusion of the meningeal membranes that cover the spinal cord).  The risk of neural tube defects can be lowered if the mother’s diet before and during pregnancy contains adequate folic acid. 



Nystagmus:  Rapid rhythmic repetitious involuntary eye movements.  Nystagmus can be horizontal, vertical or rotary.



Pharynx:  It is a hollow tube about 5 inches long that starts behind the nose and ends at the top of the trachea (windpipe) and esophagus (the tube that goes to the stomach).



Phonation:  The production of many speech sounds requires that vocal folds vibrate.  This vibration is known as phonation, voice, or voicing. 



Pons:  A specific section of the brain formed by the rounded prominence on the front surface of the brainstem. (the brain stem is the lowest part of the brain that merges with the spinal cord; it consists of a structure called the medulla oblongata, the midbrain and the pons).  Cranial nerves V,  VI,  VII,  and VIII take origin at the boarder of the pons.  Pons is Latin for “bridge.” It functions as a bridge to join the two hemispheres of the cerebellum and to connect the cerebellum with the cerebrum and with the spinal cord.

To see a picture: www.com/brainfuncthree.html


To see a picture: www.waiting.com/brainstem.html#anchor561399




Regurgitation:  A backward flowing.  For example of food or liquid.



Respiratory System: The respiratory system is composed of the air passageways (nasal cavity, pharynx, larynx, and trachea ) and lungs.  Within the lungs, the trachea branches into the bronchi, bronchioles and finally alveoli.



Sensorineural Hearing Loss: Hearing loss due to damage to the pathway for sound impulses from the hair cells of the inner ear to the auditory nerve and the brain. 



Shunt:  To bypass or divert an accumulation of fluid to an absorbing or excreting system by surgical reconstruction OR by a mechanical device as for the relief of hydrocephalus.



Spina Bifida (also known as meningomyelocele): Spina Bifida is a Latin term meaning split spine.  It is a neural tube defect (a disorder involving incomplete development of the brain, spinal cord and/or their protective coverings) that is caused by a failure of the neural tube to close during embryonic development.  The neural tube is the embryonic structure that gives rise to the brain and spinal cord.  It is a bony defect in the vertebral column so that part of the spinal cord, which is normally protected within the vertebral column, is exposed.  People with spina bifida can suffer from bladder and bowel incontinence, cognitive (learning) problems and limited mobility.  There are three types of spina bifida. 1.  Meningomyelocele is the severest, where an abnormal  spinal cord develops but the meninges protrude from a spinal opening. 2.  Meningocele is the moderately severe form of spina bifida in which meninges is in a skin covered sac and protrudes causing a bulge under the skin and the cord is relatively normal.   3. spina bifida occulta is the mildest form in which one or more vertebras are malformed and covered by a layer of skin and the spinal cord is relatively normal.  The risk of spina bifida varies according to country, ethnic group and socioeconomic status.  In the United States as a whole, spina bifida occurs in about one in every 1 to 2,000 births.  The risk of spina bifida and other neural tube defects can be decreased by women taking folic acid supplements before they conceive and during the first months of their pregnancy. 



Spine:   The column of bone known as the vertebral column, which surrounds and protects the spinal cord.  The spine can be categorized according to the level of the body: i.e.: cervical spine (neck), thoracic spine (upper and middle back) and lumbar spine (lower back).



Spinal Canal: A canal (tube, duct or passageway) that contains the spinal cord.



Spinal Cord:

 The major column of nerve tissue that is connected to the brain lies within the vertebral canal, and from which the spinal nerves emerge.  The spinal cord and brain constitute the central nervous system.  The spinal cord consists of nerve fibers that transmit nerve impulses to and from the brain.  Like the brain, the spinal cord is covered by three connective tissue envelopes called the meninges.  The space between the outer and middle envelopes is filled with cerebrospinal fluid (CSF), a clear colorless fluid that cushions the spinal cord against jarring shock.  There are 31 pairs of spinal nerves that originate in the spinal cord: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal.  In the spinal cord, information about internal and external conditions travels up the ascending tracts to the brain.  This information is processed by the brain and

corresponding responses are induced by nerve impulses traveling down the descending tracts of the spinal cord to stimulate motor neurons or to initiate secretions by glands.  

Is the extension of the brain and is protected by a bony structure called the vertebral or spinal column.  The spinal cord is covered with three membranes as the brain the meninges.



Spinal Stenosis: Narrowing of the spinal canal.  The result is compression of the nerve roots or spinal cord by bony spurs or soft tissues such as discs, in the spinal canal.  When the neck is affected, it can result in unusual sensations in the arms and / or poor leg function and incontinence. 



Stridor:  Voice quality which accompanies respiration and is characterized by the presence of a tense, non musical laryngeal noise; typically appears in young children while they sleep. 



Syncope (fainting): Pronounced sin-ko-pea.  Syncope is a partial or complete loss of consciousness with interruption of awareness of oneself and ones surroundings.  When loss of consciousness is temporary and there is spontaneous recovery, it is referred to as syncope, or in non-medical terms – fainting.  Syncope is due to a temporary reduction in blood flow and therefore a shortage of oxygen to the brain.  This leads to lightheadedness or a “black out” episode - a loss of consciousness.



Syringomyelia (pronounced sear-In-go-my-ELL-ya): This is a disorder in which a cyst forms in the spinal cord due to an obstruction of the normal flow of cerebrospinal fluid (CSF) redirecting it to the spinal cord itself.  This obstruction in the flow of CSF results in the formation of a syrinx (a cyst that fills with CSF).  When this happens, pressure differences along the spine causes the fluid to move within the cyst.  It is believed that this continual movement of fluid results in cyst’s growth (the cyst or syrinx expands and elongates over time) and further damages the spinal cord and connecting nerves. 



Syrinx:  This is a cyst that forms within the spinal cord.  A syrinx / cyst may develop in the cervical region of the spinal cord of those who have ACM.  This is because ACM obstructs the normal flow of Cerebral Spinal Fluid (CSF), redirecting it to the spinal cord itself.  This results in the formation of a syrinx (a cyst that fills with CSF).  See syringomyelia. 



Tinnitus:  Tinnitus is a sensation of sound in the head, which may be localized in one or both ears; it may also be perceived in the cranial region.  It can be perceived as any of the following: throbbing, hissing, whistling, booming, clicking, buzzing, roaring, or high pitched tone or noise.  Tinnitus may result from any auditory impairment in any location within the auditory pathway or have a vascular or muscular origin.  It is often associated with Meniere’s disease and otosclerosis.  One of the most common causes of tinnitus is damage to the microscopic endings of the hearing nerve in the inner ear. 



Torticollis:  It is a state of inadequate muscle tone in the muscles of the neck that control the position of the head.  It can cause the head to twist and turn to one side, and the head may also be pulled forward or backward.



Trachea:  Also known as the “windpipe”.  The trachea is a tube like portion of the breathing or “respiratory” tract that connects the larynx (voice box) with the bronchial parts of the lungs.



Vagus Nerve: It is the tenth cranial nerve.  It is a remarkable nerve that supplies nerve fibers to the pharynx (throat), larynx (voice box), trachea (windpipe) lungs, heart, esophagus and the intestinal tract as far as the transverse portion of the colon.  The vagus nerve also brings sensory information back to the brain from the ear, tongue, pharynx and larynx.  It originates in the medulla oblongata, as part of the brain stem and wanders all the way down from the brain stem to the colon.  The consequence is laryngeal palsy, paralysis of the larynx (voice box) on the affected side.  Laryngeal palsy can also be caused by damage to the vagus nerve before it gives off the recurrent laryngeal nerve. 







Ventricle(s):  Ventricles are pockets filled with Cerebrospinal Fluid (CSF) which flows around the brain and spinal cord.  CSF normally flows through the ventricles down through the posterior fossa and into the spinal cord. The fourth ventricle is in the  cerebellum or brainstem area. 



Vertebral Column: The 33-vertebra fit together to form a flexible, yet extraordinary tough column that serves to support the back through a full range of motions.  It also

protects the spinal cord, which runs from the brain through the hollow space in the middle of the vertebral column.  There are seven cervical (C1 – C7), twelve

thoracic (T1 - T12), five lumbar (L1 - L5), five sacral (S1 - S5) with  four coccygeal vertebrae in this column, each separated by intervertebral disks.



Vertigo:  A feeling that you are dizzily turning around or things are dizzily turning about you.  Vertigo is a medically distinct from dizziness.



 Vocal Fold(s): Also known as vocal cords. The vocal cords/folds are two bands of muscle that form a “V” inside the larynx.  These muscles vibrate to produce the voice.  The vocal folds/cords form a “V” inside the larynx, a 2-inch long tube shaped organ in the neck.  Each time we breath in air goes into our nose or mouth, then through the larynx, down the trachea and into our lungs.  When we breathe out, the air goes the other way.  When we breath the vocal cords/folds are relaxed and the air moves through the space between them without making any sound.  When we talk the vocal cords/folds tighten up and move closer together.  Air from the lungs is forced between the vocal cords/folds and makes them vibrate, producing the sound of our voice.  The movements of the tongue, lips and teeth help to form this sound into our words.  



Vocal Fold Paralysis: Inability of one or both vocal folds (vocal cords) to move.  The paralysis is usaully due to damage to the nerves going to the vocal folds/cords or due to damage to the brain itself. 

In more technical terms:


                        Vocal fold/cord paralysis may result in lesions in the:  nucleus ambiguus or its supranuclear tracts in the brain, the main trunk of the vagus nerve (see cranial nerves) , or in the recurrent laryngeal nerves (which supply the larynx), intracranial (brain) tumors, strokes, and demyelinating diseases can cause nucleus ambiguus paralysis.  Neoplasms at the base of the skull and trauma of the neck can cause paralysis of the vagus nerve.  Recurrent laryngeal paralysis is caused by neck or thoracic lesions (such as aortic aneurysm, mitral stenosis, tumors of the thyroid gland, esophagus, lung or neurotoxins (such as lead), infections (such as diphtheria), cervical spine injury or surgery or viral illness. 








Arnold Chiari Malformation (ACM) is congenital abnormality at the base of the brain in which a portinion of the cerebellum (cerebellar tonsils) protrude below the level of the Foramun Magnum. Arnold Chiari is divided into four groups or types to as related to the degree of displacement/herniaition.





The cause is unknown.  There are many speculations/theories related to the cause but none really explains all the malformations. Some literature make note of a small or underdeveloped occipital bone that limits the room in the base of the skull for the hindbrain, thus resulting in displacement/herniation as a cause.    

Although Type II is very often associated with Neural Tube Defects (NTD), such as spina bifida, hydrocephalus et cetera, it is not considered a NTD.



Clinical Presentation:


There are four types (I, II, III, IV) and clinical presentation are highly variable.  May be associated with other anomalies.






TYPE I   Chiari   Malformation


Type I presentation is characterized by a downward displacement (herniation) of the cerebellar tonsils and fourth ventricle through the foramen magnum around the cervical spinal cord.

To see a picture:     www.pressenter.com/~wacma/csf.htm.

 or    www.yvy69.ukgateway.net/1/basic.htm#top

There is also obstruction of the normal flow of Cerebral Spinal Fluid (CSF) through this area because the tonsils of the cerebellum are stuffed into the foramen magnum.  Sometimes this can result in brain stem compression, and/or the brainstem appears atrophic (shrunken) and may stick to the spinal cord.  Usually ACM Type I occurs in adults around the third or fourth decade of life. Most people with ACM Type I may have no obvious symptoms.  It is very rare for trauma to “cause” Chiari, but trauma can “trigger” symptoms in a Chiari patient even if they never had symptoms before.





PHONATION                                         RESPIRATION                      ARTICULATION                                    MOTOR

~disordered esophageal motility     ~chest pain                           ~slowness and slurred speech                       ~ataxia

~bilateral vocal fold paralysis                           ~apnea                                                                                                  ~choking

                                                                                                                                       ~ general muscle weakness    

~dysphonia                                                                                                                                                           ~drooling

~gastroesophageal reflux                                                                                                                             ~dysphagia


AUDITORY                                             VISUAL                                                                  OTHER

~sensorineural hearing loss                    ~nystagmus:                                                                ~numbness

~vertigo                                     intolerance to                                                  ~sensation of hot extremities

~tinnitus                                     bright light                                                             ~weakness / fatigue

                                                ~diplopia                                                                               ~headache

LANGUAGE                                      ~difficulty tracking                                                     ~syncope

~word retrieval difficulties              ~pain/pressure behind eyes                                  ~weight loss

                                                                                                            ~fusion of cervical spine


                                                                                ~back pain

                                                                                                            ~cervical pain

~headache induced by         coughing



                                                                                                                                                ~pressure on neck

                                                                                                                                                ~neck spasms

                                                                                                                                                ~neck pain

                                                                                                                                                ~ jaw / ear / eye pain


~tingling extremities

~hand tremors










TYPE II   Chiari   Malformation


Type II usually diagnosed at birth or infancy.  It is characterized by a further downward displacement (herniaition) of the cerebellar tonsils and fourth ventricle at the foramen magnum into the cervical spinal cord. A kink in the medulla occurs in 55% of the cases of Type II which may cause brain stem or cervical cord compression.  Type II is almost always associated with spina bifida, and hydrocephalus and all their clinical problems.  




PHONATION                         RESPIRATION                        ARTICULATION                  MOTOR IN GENERAL

                                                ~apnea                                  ~slowness & slurred          ~ataxia

~vocal cord paralysis          ~tracheal aspiration                                                                            ~motor & sensory disorders

~gastroesophageal reflux        ~gagging                                                                                 ~muscle weakness of the

~cricopharyngeal                     ~achalasia                                                                       face/hands/legs/arms

~pharyngoesophageal                                                                                                       ~swallowing difficulties

   dysmotility                                                                                                                          ~drooling

~weak cry                                                                                                                               ~perceptual motor prblms




AUDITORY                             VISUAL                                  LANGUAGE                           OTHER

 ~deafness                           ~diplopia (double vision)   ~learning disabilities          ~sensory disturbance

~blurred vision                        ~comprehension prblms                ~bilateral upper arm

                                                 ~pragmatic prblms                   weakness and wasting

                                                                                                                                                ~cyanotic spells

                                                                                                                                                ~neck pain


                                                                                                                                                ~syncope (fainting)


~varying degrees of mental        


~bradycardia (slow heart)


~memory problems



~ syringomyelia


~ incontinence







TYPE III   Chiari   Malformation


Rare.  Diagnosed at birth, Type III consists of further herniation of the entire cerebellum below the foramen magnum often forming an encephalocele.   What this basically means is that the back of the brain protrudes out of an opening in the back of the skull area.  These individuals have portions of the cerebellum and brainstem in the upper spinal canal. 



TYPE IV   Chiari   Malformation


Very Rare.  Type IV is also diagnosed at birth.  Type IV is in fact not a hindbrain herniation at all in contrast to Types I – III.  It is associated with underdeveloped  (hypoplasia) cerebellum or a failure to develop (aplasia).  In Type IV the back of the brain fails to develop normally.  Usually back portions of the head and spinal column are open to the outside. 





Type I: Due to the vague nature of the symptoms and the variable course, misdiagnosis is common.  Patients are frequently diagnosed with Multiple Sclerosis (MS), Amyotrophic Lateral Sclerosis (ALS), Myasthenia Gravis, Muscular Dystrophy (MD), Cervical Spondylosis, Cervical Myelopathy and Chronic Fatigue Syndrome (CFS).  Other patients are labeled as “neurotic” because of the vague complaints of headache and sensory abnormalities. 


NOT ALL patients have a classical picture of the deeply herniated tonsils.


Individuals who suspect that they have ACM should be evaluated by a neurologist or neurosurgeon with experience in the treatment of Arnold Chiari Malformation.

A Good examination should not only include the physical abnormalities of the motor, sensory and reflex systems but also the patient’s subjective report of pain and dysesthesia (numbness). The best prognostic tool for identifying ACM is high quality Nuclear Magnetic Resonance (NMR/MRI).






            Early recognition and intervention by a neurosurgeon are therefore crucial in ensuring a favorable neurological outcome.  There are many ways to treat ACM but they all require surgery.  Currently there are over 20 different practiced operations to either decompress or divert Cerebral Spinal Fluid (CSF) pressure.  The operations include but are not limited to:  decompressing the brainstem by surgically removing part of some of the cervical vertebra and the lowest part of the skull, shunt placement and reconstruction of a larger posterior fossa.  Some studies suggest that patients with pronounced motor and sensory deficits have the worst prognosis for recovery. 






A Guide to Brain Anatomy

Retrieved August 2001 from the World Wide Web




Anencephaly Support Foundation

            Retrieved August 2001 from the World Wide Web








Bates, Sarah. Arnold Chiari patient and former nurse. 

Personal e-mail correspondence




The British United Provident Association

Retrieved August 2001 from the World Wide Web




Brum, G., McKane, L., Karp, G. (1989).  Biology: Exploring Life Second Edition. New

            York:  John Wiley & Sons, Inc.




Terms / Definitions  with overview of  ARNOLD  CHAIRI  MALFORMATION






Children’s Hospital Boston: Child Health A to Z, Neurological Service, Chiari


            Retrieved August 2001 from the World Wide Web




Colton, R., Casper, J. (1996).  Understanding Voice Problems: A Physiological

Perspective for Diagnosis and Treatment.  Baltimore, Maryland: Lippincott Williams & Wilkins. 



Deem. J., Miller, L. (2000).  Manual of Voice Therapy.  Austin Texas: Pro-ed. 



Guyton, Fallon.  Are symptoms in Chiari Malformation Gender Related?

            Retrieved May 2001 from the World Wide Web




Grigg, Kathleen.  Arnold Chiari patient and moderator of the World Arnold

Chiari Malformation Association.

Personal e-mail correspondence 

< grigg@javanet.com



Graaff, K, Rhees, R. (1987).  Schaum’s Outline of Theory and Problems of Human

            Anatomy and Physiology.  New York: McGraw-Hill Book Company.



INN Pediatric Neurosurgery.  Arnold Chiari Malformation Introduction

            Retrieved August 2001 from the World Wide Web




Kiernan John.  Anatomical Foundations of Neuroscience

            Retrieved August 2001 from the World Wide Web








MacKay, I. (1987).  Phonetics: The Science of Speech Production Second Edition. 

Boston:  Little Brown & Company.



Myelodysplasia.  Myelodysplasic Syndromes

            Retrieved August 2001 from the World Wide Web




National Institute of Neurological Disorders and Stroke

            Spina Bifida Information Page

            Retrieved August 2001 from the World Wide Web




Nicolosi, L., Harryman, E., Kresheck, J. (1989).  Termnology of Communication

Disorders Speech-Language-Hearing Third Edition.  Baltimore, MD: Williams & Wilkins.



Nishikawa, Misao, M.D.  Pathogenesis of Chiari Malformation: A morphomtric Study of

Posteria Cranial Fossa.  Osaka, Japan: Department of Neurosurgery and Radiology, Osaka City University Medical School.

Retrieved August 2001 from the World Wide Web




Perkins, W., Kent, R. (1986).  Functional Anatomy of Speech, Language, and

            Hearing A primer. New York: Little Brown & Co.



Dr. ML Grunnet. Synopsis of Meningomyelocele of the Spinal Cord

Medline at National Library of Medicine

Retrieved August 2001 from the World Wide Web





Retrieved August 2001 from the World Wide Web








National Institute of Neurological Disorders

Retrieved August 2001 from the World Wide Web




PubMed –indexed for MEDLINE

Retrieved May 2001 from the World Wide Web


then type in number listed for each article listed below



11082884        Episodes of unilateral sympathetic hyperfunction, changes in consciousness status and respiratory dysfunction in a girl with type II Chiari malformation

9152746          Laryngealogic management of infants with Chiari II syndrome  

8617124          Esophageal dysphagia as the sole symptom in type I Chiari malformation

2360371          Brain stem dysfunction in Arnold Chiari II Syndrome

3625403          Management of Chiari II complications in infants with myelomeningocele

7383257          Severe respiratory and swallowing disturbances associated with Arnold Chiari malformation

639601            Cricopharyngeal achalasia associated with Arnold Chiari malformation in childhood

1584383          Neurogenic dysphagia resulting from Chiari malformations



School of Biological Services The Human Cranial Nerves

            Retrieved August 2001 from the World Wide Web




Syringomyelia Facts, Do You Have Any of These Symptoms?

            Retrieved August 2001 from the World Wide Web




Tomblin, J., Morris, H., Spriestersbach, D.C. (2000).  Diagnosis in Speech Language

Pathology Second Edition.  San Diego, California:  Singular Publishing Company.



United Kingdom Arnold Chiari and Syringomyelia Association. Welcome to the UK’s

            First A.C. and S.M. Web Site!

            Retrieved May 2001 from the World Wide Web




University of Manchester.  The Foramen Magnum and the Vagus Nerve

            Retrieved August 2001 from the World Wide Web






Watt, Ronnie. What are the Symptoms of Chiari? 

            Retrieved May 2001 from the World Wide Web



World ACM Association – Home

Retrieved May 2001 from the World Wide Web




World Arnold Chiari Malformation Association.

            Retrieved May 2001 from the World Wide Web




Zemlin,W. (1988).  Speech and Hearing Science Anatomy and Physiology Third Edition.

            New Jersey:  Prentice Hall.