Chapter 1. Concept of Sleep Medicine and of Neurosomnology

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Neurosomnology is an active subspecialty of neurology and of sleep medicine

that will acquire increasing notoriety among neuroscientists and clinical neurologists as basic and clinical research continue to unravel the neurological intricacies

of sleep and its disorders. To advance the subject of sleep, the doors to the brain

need to be opened and those who can open them are neuroscientists by training

or by adoption. Neurosomnologists should have supra-specialized knowledge of

the links between sleep and stroke, epilepsy, neuromuscular disorders, movement

disorders, multiple sclerosis, neurodegenerative disorders, headaches, and traumatic brain injury. They should also possess in-depth knowledge of intrinsic

brain sleep disorders such as narcolepsy, idiopathic hypersomnia, REM sleep behavior disorder, parasomnias, circadian dysrhythmias, and fatal familial insomnia.

Worthy sleep centers need subspecialists in neurosomnology. Encouraging

a sleep center to have a neurologist on board is not sufficient. There should be a

guarantee that a neurologist with expertise in sleep disorders is in the staff. The

day will come when that expertise is documented with a certificate in neurosomnology, verifying that the professional is an expert in neurological sleep disorders.

To achieve such lofty goal, I have suggested exploring the acquisition of a

certificate in the subspecialty of neurosomnology through the American

Academy of Neurology (AAN)-sponsored United Council for Neurologic Subspecialties (http://www.ucns.org/certification/applications) mechanism. My vision

is that certified neurologists who are American Board of Sleep Medicine (ABSM)

diplomates or American Board of Internal Medicine (ABIM)-certified in sleep

medicine would be eligible to reach this very specialized branch of neurology.

The certificate would become an addition to the current title of specialist in

sleep medicine, not a substitute. It should have no effect in the feared split of sleep

medicine into sleep apnea disorders (80% of current sleep medicine) and everything else, as only sleep specialists would be eligible. The new title would

empower the presence of neurologists in all sleep centers, improving the evaluation

and management of patients and conferring rationality to the process, as sleep is,

after all, a function of the brain.

CORPORATE ORGANIZATION OF SLEEP MEDICINE

The AASM (http://www.aasmnet.org) is the core sleep organization in the United

States. Its mission is to enhance the quality and effectiveness of health care by

fostering excellence and professionalism in the field of Sleep Medicine. It strives

to assure quality care for patients with sleep disorders, the advancement of

sleep research, and public and professional education. In 2005, AASM listed 2993

diplomates in Sleep Medicine (Fig. 1) and 550 accredited sleep centers. AASM publishes the journals Sleep and the Journal of Clinical Sleep Medicine and participates

in the organization of the Associated Professional Sleep Societies Annual meeting

(APSS, http://www.apss.org) that celebrated its 20th anniversary at the Salt Lake

City convention in June 2006.

ACCREDITATION

AASM also offers accreditation of sleep centers and sleep-related breathing laboratories. This is a voluntary process that serves to document and validate excellence

in the provision of care in Sleep Medicine. It serves to guarantee that the center has

met all standards set by the AASM, such as employing skilled and qualified staff,



Concept of Sleep Medicine and of Neurosomnology



3



Diplomates 1978 - 2005: 3,993

3500



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Total Number of Diplomates



FIGURE 1 Graph showing the growth of diplomate members since 1978. Provided by the American

Academy of Sleep Medicine.



creating a clean and comfortable environment, developing a quality assurance plan,

and adhering to evidence-based practice parameters. Accreditation is given for a

period of five years.

FELLOWSHIP TRAINING AND CERTIFICATION IN SLEEP MEDICINE

In June 2004, the American Council for Graduate Medical Education (ACGME)

(http://www.acgme.org) approved the program requirements for graduate

medical education in the subspecialty of Sleep Medicine. Sleep Medicine is

defined as “a discipline of medical practice in which sleep disorders are assessed,

monitored, treated, and prevented by using a combination of techniques and medication.” Fellowship education must be undertaken following ACGME-approved

training programs in any of the following specialties: neurology (four years), internal

medicine (three years), pediatrics (three years), psychiatry (four years), and otolaryngology (five years). Fellowship training in Sleep Medicine should be separate

from all other specialties, but should provide exposure to neurology, cardiology,

otolaryngology, oral maxillofacial surgery, pediatrics, pulmonary medicine, psychiatry, psychology, and neuropsychology. Fellowship programs can only be accredited in institutions where the sponsoring specialty has an ACGME-accredited

residency program.

One or more institutions may participate in the training program, but there

must be assurance of continuity of the educational experience. There should be

only one sleep center per facility. Resources must include sufficient inpatient and

outpatient populations of all ages encompassing the major categories of sleep

disorders that include: sleep apnea, narcolepsy, parasomnias, circadian rhythm



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disorders, insomnia, and sleep problems related to internal medicine, neurology,

and psychiatry. The facility should have a minimum of two fully equipped polysomnography bedrooms and support space; it should also contain meeting

rooms, office space, educational aids, library materials, and diagnostic, therapeutic,

and research facilities. Sleep laboratories should be accredited by the AASM or an

equivalent body.

The program director is accountable for the operation of the program and

should be fully committed to the fellowship program and its fellows. The

program director must be a diplomate of the ABSM or be certified in Sleep Medicine

by the ABIM and possess qualifications judged to be acceptable by the residency

review committee (RRC). There must also be a sufficient number of participating

faculties with documented qualifications to instruct fellows in the program.

There should be at least two core faculties, including the director, who are

specialists in any of the recognized sponsoring specialties and who are certified

in Sleep Medicine. Faculty should be available to participate in consultation and

teaching in disciplines related to Sleep Medicine including cardiology, neurology,

otolaryngology, oral maxillofacial surgery, pediatrics, pulmonary medicine,

psychiatry, and psychology.

An atmosphere of scholarship must prevail as evidenced by peer-reviewed

funding or by publication of original research in peer-reviewed journals,

production of review articles and chapters in textbooks, and presentation of case

reports, or clinical series at local, national, or international scientific meetings.

In addition, there should be participation in journal clubs, grand rounds, and

research conferences.

The program curriculum should be approved by the RRC. The program must

be didactic and clinical and fellows should have the opportunity to participate in

research. The didactic program should cover all areas of sleep medicine, as well

as techniques for diagnostic assessment, administration and interpretation of

tests, financing and regulation of sleep medicine, medical ethics, legal aspects,

and research methods. In addition, there should be seminars and conferences in

all areas of sleep medicine and related specialties. The clinical skills should

focus on interviewing patients, history taking, physical examination, formulating

a differential diagnosis, diagnosis, treatment plans, and continuous care.

Overall, fellows must have at the completion of their training formal instruction, clinical experience and competence in all areas of Sleep Medicine. They should

be able to work in outpatient and inpatient settings and effectively utilize healthcare resources. All patient care must be supervised by qualified faculty. Duty

hours must be limited to 80 hours per week, averaged over a four-week period,

inclusive of all in-hours call activities. One in seven days should be free from all

educational and clinical responsibilities. Final evaluation of a fellow completing

the program must include a review of the fellow’s performance and should

verify that the fellow has demonstrated sufficient professional ability to practice

competently and independently. Fellows thus trained may seek certification in

Sleep Medicine by the ABIM newly recognized sleep board.

OTHER NATIONAL AND INTERNATIONAL SLEEP SOCIETIES

The Sleep Research Society (SRS) (http://www.sleepresearchsociety.org) fosters

scientific investigation, professional education, and career development in sleep

research and academic Sleep Medicine at both the national and international



Concept of Sleep Medicine and of Neurosomnology



5



levels. In 2005, SRS had 1090 registered members, 30% international from

32 countries. SRS is closely allied with the AASM.

The Academy of Dental Sleep Medicine (ADSM) (http://www.dentalsleepmed.org) is a professional membership organization promoting the use and

research of oral appliances and oral surgery for the treatment of sleep disordered

breathing. It provides training and resources for those who work directly with

patients. In 2005, there were 540 members, mostly in North America. The ADSM

is closely allied with the AASM.

The ABSM (http://www.absm.org) was established in 1978 to encourage the

study, improve the practice, elevate the standards of Sleep Medicine, and issue certificates of special knowledge in Sleep Medicine. ABSM is closely allied with the

AASM. ABSM has been a “rogue” board, not recognized by the American Board

of Medical Specialities (ABMS), but accepted by most institutions in the United

States as the “Sleep Board.” Specialists certified by the ABSM are called diplomates.

The last ABSM exam will be given in the fall of 2006. The first board exam in

the specialty of sleep recognized by the ABMS will be given in the fall of 2007

by the ABIM. Having ABMS recognition, individuals who pass the exam may

claim to be certified in Sleep Medicine.

The Association of Polysomnographic Technologists (http://www.

aptweb.org) is an international society of professionals dedicated to improve the

quality of sleep and wakefulness in all people. In 2005, there were 1540 members

mostly technologists. The Board of Registered Polysomnographic Technologists

(http://www.brpt.org) certifies individuals in polysomnographic techniques while

promoting national and international recognition and acceptance of the RPSGT

credential as the professional standard for polysomnographic technologists. The

board is active in the United States, Canada, China, Japan, and Australia. Exams

are given annually.

The AAN (http://www.aan.com) supports a Sleep Section with 450 members

in 2006, charged with organizing the educational and scientific presentations at

AAN annual meetings.

The World Federation of Neurology (http://www.wfneurology.org) sponsors

a Sleep Research Group that intervenes in the organization and structure of symposia and educational courses at the World Congress of Neurology. The next congress

will take place in Bangkok in 2009.

International Congresses of Sleep Medicine are also organized at the regional

and world levels. The World Association of Sleep Medicine (http://www.wasm.

org) held the first Congress of Sleep Medicine in Berlin in 2005. It was attended

by almost 1000 registrants, indicating the vigor of the specialty at the international

level. In view of the initial success, the Second World Congress of Sleep Medicine

was held in Bangkok, Thailand, in February 2007.

The World Federation of Sleep Research Societies (http://www.sleepresearchsociety.org) also organizes international meetings, such as the one in Cairns,

Australia in 2007.

Regional international congresses in sleep medicine have been held at various

times in the recent past organized by European, Latin American, and Asian societies.

FUTURE

Sleep Medicine will grow exponentially in the foreseeable future. Much of that

growth will come in the heels of the expansion of neurosomnology. Sleep is a



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function localized in brain structures, which follows the dynamics of maturation,

evolution, and decay of other complex functions also localized in the brain, such

as motor development, cognition, and language. There is no one cerebral center

where sleep lodges but a multiplicity of structures tightly linked in a network of

nuclei, tracts, and neurotransmitters that respond to the orchestrating mandates

of the circadian rhythm. Basic research in the neurosciences will advance the understanding of sleep as a ubiquitous function of the nervous system present in all

vertebrates. The demands to comprehend and manage sleep dysfunctions, to

study its pathology, and to develop treatment modalities will come from

a variety of fronts, the most obvious of which has been sleep disorders as a

medical discipline in which individual ailments such as narcolepsy, sleep apnea,

and others are studied. Developing fronts are also emerging in the academic

sector where educators are requesting increased learning efficiency, a process that

requires an alert brain. Other fronts have appeared in government departments,

where authorities are concerned about fatigue eroding safety on the road; in industry and labor, where leaders are asking for guidance in shift-work programs; and

in aerospatial science, where jet-lag distortions of sleep and wakefulness create

safety hazards. Indeed, neurosomnology is destined to develop as a subspecialty

of the neurosciences with a corporate structure of its own.

REFERENCE

1. American Academy of Sleep Medicine. ICSD-2, International Classification of

Sleep Disorders. Diagnostic and Coding Manual. 2nd ed. Westchester, Illinois, American

Academy of Sleep Medicine, 2005.



Part II: Infancy and Development



B

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Disorders of Development and

Maturation of Sleep

Stephen H. Sheldon

Sleep Medicine Center, Children’s Memorial Hospital,

Chicago, Illinois, U.S.A.



INTRODUCTION

Disorders of the central nervous system (CNS) are often associated with sleep

disturbances. Frequently, children who are neurologically challenged experience

chronic sleep–wake problems related to circadian timing of sleep, sleep-related

seizures, sleep-related movement disorders, and sleep-related breathing disorders.

Traditional therapeutic interventions are often difficult and/or the response is quite

variable. Behavioral management, chronotherapy, phototherapy, faded response programs, sedatives, hypnotics, and antidepressants are often unsuccessful in the youngster with a chronic disabling condition of the CNS. Some traditional therapeutic

approaches may even exacerbate symptoms or result in only respite for a few days.

Symptoms range from profound sleep onset difficulties at desired bedtimes,

inability to consolidate sleep, inability to maintain sleep, irregular sleep – wake schedules, rapidly changing sleep – wake schedules, obstructive sleep apnea syndrome,

disorders of the central control of breathing, seizures during sleep, movement disorders, and arousal disorders. Presence of multiple symptoms is the rule, rather

than exception. Sleep deprivation and fragmentation of sleep continuity occurs

and considerable performance problems, as well as delay in the response to rehabilitative efforts, can result. Interestingly, not only do these disorders of sleep and the

sleep – wake cycle deeply affect the patient and quality of life, but commonly result

in sleep disturbances and decreased quality of life for the entire family.

This chapter addresses normal development of the CNS and sleep, anatomical

correlates, and the effect that specific CNS abnormalities might have on sleep and

the sleep –wake cycle. Finally, suggestions regarding management are entertained.

NORMAL AND ABNORMAL DEVELOPMENTAL AND ANATOMICAL

CORRELATES OF THE CENTRAL NERVOUS SYSTEM AND SLEEP

The CNS is the predominant organ system governing sleep, sleep’s components,

and the sleep –wake cycle. Major CNS alterations occur throughout fetal life,

neonatal life, infancy, and childhood. Understanding these changes is essential in

assessing the patient with CNS dysfunction during wakefulness and during

sleep. Indeed, a comprehensive awareness of maturational changes during sleep

may provide insight into management.

Genetic and environmental factors are important in determining morphological and electrophysiological development of the CNS. Differentiation begins very

early in the evolution of the embryo as a thickening of the dorsal ectoderm into

the neural plate. This single layer of cells rapidly enlarges in number, stratifies,

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and develops two folds and a neural groove. This central groove fuses to become

the neural tube giving rise to the substance of all neural elements whose cell

bodies and supporting elements lie within the brain and spinal cord (1).

Early in the fourth postconceptional (PC) week, the prosencephalon subdivides the forebrain into the telencephalon and diencephalon. Telencephalon represents primordial development of the cerebral hemispheres and diencephalon is

destined to become the area containing the optic vesicles. Rhombencephalon

develops later into the cerebellum and pons. Myelencephalon is the primitive

medulla oblongata and matures somewhat later in embryogenesis.

During regional differentiation, structural flexure begins. Three regions can

be identified: cephalic flexure (region of the midbrain), cervical flexure (junction

of the brain and spinal cord), and pontine flexure (junction of the metencephalon

and myelencephalon). In addition, the lumen of the neural tube undergoes dramatic changes during this time, which corresponds to regional specialization.

The lumen in the area of the telencephalon extends into the paired future cerebral

hemispheres and will ultimately become the lateral ventricles. The lumen within

the telencephalon and diencephalon will become the third ventricle. Cerebral aqueduct develops from the lumen in the mesencephalon. The lumen of the metencephalon and myelencephalon becomes the fourth ventricle.

Neuronal activity appears to be important in the migration of neurons to

appropriate positions within the CNS, degree of dendritic branching, and strength

of synaptic interconnections (2). Mitosis and migration continue throughout development, and completion of location of individual neurons occurs about one year

after PC term. Two internal processes result in a high degree of neuronal activity:

the waking state and active [rapid eye movement (REM)] sleep. It is possible that

these two states are important during prenatal and early postnatal life for appropriate ultra-structural development of the CNS.

Centers responsible for control of sleep and the sleep – wake cycles are contained in areas, which will develop from the diencephalon. Appropriate diencephalic maturation is essential for normal sleep to occur. All neuronal activity which

eventually reaches the cortex passes through the diencephalon, with the sole exception of those originating from olfaction. The third ventricle is contained within the

diencephalon. During the seventh week of development, a small evagination

appears from the caudal wall of the third ventricle. This eventually becomes glandular and forms the pineal body, which is responsible for secretion of melatonin.

Melatonin plays an important role in regulating the sleep– wake cycle

presumably through entrainment to light–dark cycling. Secretion is highly responsive to afferent neural activity via the retino-hypothalamic tract. Secretion increases

in dark environment and is decreased when the retina are exposed to light.

Although data regarding the function of melatonin are conflicting, evidence exists

that it affects the timing of sleep through its effect on circadian organization (3).

Exogenous melatonin has been noted to be useful in regulating sleep in some

sleep disorders (4) and in improving sleep in some neurologically handicapped

children (5). It seems likely, therefore, that disorders of development of the diencephalon as well as acquired disorders which affect development or function of cells in

the caudal wall of the third ventricle can result in significant sleep–wake disorders.

After the seventh PC week, thalamic regions undergo differentiation and

neuronal fibers separate the massive gray matter of the walls of the thalamus

into numerous thalamic nuclei. Similarly, the wall of the hypothalamus contains

hypothalamic nuclei, the optic chiasm, suprachiasmatic nucleus, and neural lobe

of the stalk of the body of the pituitary gland. Hypothalamus eventually becomes