scholarly journals Eventual Entrainment of the Human Circadian Pacemaker by Melatonin is Independent of the Circadian Phase of Treatment Initiation: Clinical Implications

2004 ◽  
Vol 19 (1) ◽  
pp. 68-75 ◽  
Author(s):  
Alfred J. Lewy ◽  
Jonathan S. Emens ◽  
Rebecca A. Bernert ◽  
Bryan J. Lefler
Keyword(s):  
Treatment Initiation ◽  
Clinical Implications ◽  
Circadian Pacemaker ◽  
Circadian Phase

scholarly journals High Sensitivity of the Human Circadian Melatonin Rhythm to Resetting by Short Wavelength Light

2003 ◽  
Vol 88 (9) ◽  
pp. 4502-4505 ◽  
Author(s):  
Steven W. Lockley ◽  
George C. Brainard ◽  
Charles A. Czeisler
Keyword(s):  
Ganglion Cells ◽  
Light Exposure ◽  
Monochromatic Light ◽  
High Sensitivity ◽  
Photon Density ◽  
Retinal Ganglion ◽  
Circadian Pacemaker ◽  
Melatonin Rhythm ◽  
Circadian Phase ◽  
Short Wavelength Light

The endogenous circadian oscillator in mammals, situated in the suprachiasmatic nuclei, receives environmental photic input from specialized subsets of photoreceptive retinal ganglion cells. The human circadian pacemaker is exquisitely sensitive to ocular light exposure, even in some people who are otherwise totally blind. The magnitude of the resetting response to white light depends on the timing, intensity, duration, number and pattern of exposures. We report here that the circadian resetting response in humans, as measured by the pineal melatonin rhythm, is also wavelength dependent. Exposure to 6.5 h of monochromatic light at 460 nm induces a two-fold greater circadian phase delay than 6.5 h of 555 nm monochromatic light of equal photon density. Similarly, 460 nm monochromatic light causes twice the amount of melatonin suppression compared to 555 nm monochromatic light, and is dependent on the duration of exposure in addition to wavelength. These studies demonstrate that the peak of sensitivity of the human circadian pacemaker to light is blue-shifted relative to the three-cone visual photopic system, the sensitivity of which peaks at ∼555 nm. Thus photopic lux, the standard unit of illuminance, is inappropriate when quantifying the photic drive required to reset the human circadian pacemaker.

Timing of human sleep: recovery process gated by a circadian pacemaker

1984 ◽  
Vol 246 (2) ◽  
pp. R161-R183 ◽  
Author(s):  
S. Daan ◽  
D. G. Beersma ◽  
A. A. Borbely
Keyword(s):  
Sleep Deprivation ◽  
Sleep Onset ◽  
Recovery Process ◽  
Bed Rest ◽  
Circadian Pacemaker ◽  
Phase Dependence ◽  
Circadian Phase ◽  
Sleep Timing ◽  
Human Sleep ◽  
Partial Sleep Deprivation

A model for the timing of human sleep is presented. It is based on a sleep-regulating variable (S)--possibly, but not necessarily, associated with a neurochemical substance--which increases during wakefulness and decreases during sleep. Sleep onset is triggered when S approaches an upper threshold (H); awakening occurs when S reaches a lower threshold (L). The thresholds show a circadian rhythm controlled by a single circadian pacemaker. Time constants of the S process were derived from rates of change of electroencephalographic (EEG) power density during regular sleep and during recovery from sleep deprivation. The waveform of the circadian threshold fluctuations was derived from spontaneous wake-up times after partial sleep deprivation. The model allows computer simulations of the main phenomena of human sleep timing, such as 1) internal desynchronization in the absence of time cues, 2) sleep fragmentation during continuous bed rest, and 3) circadian phase dependence of sleep duration during isolation from time cues, recovery from sleep deprivation, and shift work. The model shows that the experimental data are consistent with the concept of a single circadian pacemaker in humans. It has implications for the understanding of sleep as a restorative process and its timing with respect to day and night.

scholarly journals Absence of Central Circadian Pacemaker Abnormalities in Humans With Loss of Function Mutation in Prokineticin 2

2014 ◽  
Vol 99 (3) ◽  
pp. E561-E566 ◽  
Author(s):  
Ravikumar Balasubramanian ◽  
Daniel A. Cohen ◽  
Elizabeth B. Klerman ◽  
Duarte Pignatelli ◽  
Janet E. Hall ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
Medical Center ◽  
Core Body Temperature ◽  
Academic Medical Center ◽  
Pacemaker Activity ◽  
Circadian Pacemaker ◽  
Loss Of Function ◽  
Neurobehavioral Performance ◽  
Circadian Phase ◽  
Prokineticin 2

Context: Loss of prokineticin 2 (PROK2) signaling in mice disrupts circadian rhythms, but the role of PROK2 signaling in the regulation of circadian rhythms in humans is undetermined. Objective: The aim of the study was to examine the circadian rhythms of humans with a complete loss-of-function PROK2 mutation using an inpatient constant routine (CR) protocol. Design and Setting: We conducted a case study in an academic medical center. Subjects and Methods: Two siblings (one male and one female, ages 67 and 62 y, respectively) with isolated GnRH deficiency (IGD) due to a biallelic loss-of-function PROK2 mutation were studied using an inpatient CR protocol. Historical data from inpatient CR protocols conducted in healthy controls (ages 65–81 y) were used for comparison. Main Outcome Measures: We measured circadian phase markers (melatonin, cortisol, and core body temperature) and neurobehavioral performance (psychomotor vigilance task [PVT] and subjective alertness scale). Results: Circadian waveforms of melatonin and cortisol did not differ between the IGD participants with PROK2 mutation and controls. In both IGD participants, neurobehavioral testing with PVT showed disproportionate worsening of PVT lapses and median reaction time in the second half of the CR. Conclusions: Humans with loss of PROK2 signaling lack abnormalities in circadian phase markers, indicating intact central circadian pacemaker activity in these patients. These results suggest that PROK2 signaling in humans is not required for central circadian pacemaker function. However, impaired PVT in the PROK2-null participants despite preserved endocrine rhythms suggests that PROK2 may transmit circadian timing information to some neurobehavioral neural networks.

Effects of Selected Rhinologic Disorders on the Perception of Nasal Resonance in Children

1984 ◽  
Vol 15 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Michael P. Rastatter ◽  
Melvin Hyman
Keyword(s):  
Allergic Rhinitis ◽  
Clinical Implications ◽  
Normal Children ◽  
Nasal Resonance

A group of sophisticated listeners judged the nasal resonance characteristics of normal children versus children evidencing selected rhinologic disorders under three speaking conditions. Results showed that perceptions of denasality are influenced by both speakers and speaking tasks. That is, children with allergic rhinitis and edemic adenoids were perceived as being denasal when they produced VCV utterances and recited sentences. However, their resonance characteristics were deemed normal for vowel productions. Interestingly, children with severely deviated septums were judged to have normal nasal resonance under all speaking conditions. Clinical implications are discussed.

Perceptions of Stuttering of Different Age Groups

2019 ◽  
Vol 4 (6) ◽  
pp. 1311-1315
Author(s):  
Sergey M. Kondrashov ◽  
John A. Tetnowski
Keyword(s):  
Age Groups ◽  
School Age Children ◽  
Clinical Implications ◽  
School Age ◽  
Fourth Edition ◽  
Self Perception ◽  
Behavioral Measures ◽  
Self Rating ◽  
Comparison Results ◽  
Subject Pool

Purpose The purpose of this study was to assess the perceptions of stuttering of school-age children who stutter and those of adults who stutter through the use of the same tools that could be commonly used by clinicians. Method Twenty-three participants across various ages and stuttering severity were administered both the Stuttering Severity Instrument–Fourth Edition (SSI-4; Riley, 2009 ) and the Wright & Ayre Stuttering Self-Rating Profile ( Wright & Ayre, 2000 ). Comparisons were made between severity of behavioral measures of stuttering made by the SSI-4 and by age (child/adult). Results Significant differences were obtained for the age comparison but not for the severity comparison. Results are explained in terms of the correlation between severity equivalents of the SSI-4 and the Wright & Ayre Stuttering Self-Rating Profile scores, with clinical implications justifying multi-aspect assessment. Conclusions Clinical implications indicate that self-perception and impact of stuttering must not be assumed and should be evaluated for individual participants. Research implications include further study with a larger subject pool and various levels of stuttering severity.

Treatment Considerations for Adolescents Who Exhibit Cognitive/Communication Problems: A Neuroscience Perspective

2020 ◽  
Vol 5 (6) ◽  
pp. 1767-1775
Author(s):  
Martha S. Burns
Keyword(s):  
Social Communication ◽  
Transition Period ◽  
Clinical Intervention ◽  
Review Article ◽  
Sensitive Period ◽  
Clinical Implications ◽  
Evidence Based ◽  
Communication Problems ◽  
Treatment Considerations ◽  
Behavioral Growth

Purpose Adolescence is a period of substantial neurophysiological and behavioral growth, representing a second sensitive period of brain development. It is a psychological and social transition period between childhood and adulthood with many beneficial changes occurring, especially with respect to potential responsiveness to clinical intervention. However, adolescent behavioral complexities introduce clinical challenges as well. The purpose of this review article is to review the current neuroimaging research on neurophysiological changes observed during adolescence and the cognitive and social behavioral counterparts, with specific attention to the clinical implications. The review article will then summarize currently available intervention tools that can be utilized by speech-language pathologists working with this population. It will conclude with available evidence-based social-communication approaches that may be applicable as well as available evidence-based supplemental technological cognitive interventions that may be useful in working with adolescents who exhibit language and communication issues. Conclusion As a transition period between childhood and adulthood, adolescence represents a second sensitive period during which there is opportunity for clinically derived beneficial cognitive and communication growth.

Laryngeal Manifestations of Autoimmune Diseases

2020 ◽  
Vol 5 (2) ◽  
pp. 439-456
Author(s):  
Jenny L. Pierce
Keyword(s):  
Autoimmune Disease ◽  
Autoimmune Diseases ◽  
Patient Outcomes ◽  
Correct Diagnosis ◽  
Upper Airway ◽  
Clinical Implications ◽  
Laryngeal Function ◽  
The Past ◽  
Referral Practices ◽  
Timely Referral

Purpose This review article provides an overview of autoimmune diseases and their effects on voice and laryngeal function. Method A literature review was conducted in PubMed. Combinations of the following keywords were used: “autoimmune disease and upper airway,” “larynx,” “cough,” “voice,” “dysphonia,” and “dyspnea.” Precedence was given to articles published in the past 10 years due to recent advances in this area and to review articles. Ultimately, 115 articles were included for review. Results Approximately 81 autoimmune diseases exist, with 18 of those highlighted in the literature as having laryngeal involvement. The general and laryngeal manifestations of these 18 are discussed in detail, in addition to the clinical implications for a laryngeal expert. Conclusions Voice, breathing, and cough symptoms may be an indication of underlying autoimmune disease. However, these symptoms are often similar to those in the general population. Appropriate differential diagnosis and timely referral practices maximize patient outcomes. Guidelines are provided to facilitate correct diagnosis when an autoimmune disease is suspected.

The Nature of Deviant Articulation

1973 ◽  
Vol 38 (2) ◽  
pp. 156-161 ◽  
Author(s):  
Laurence B. Leonard
Keyword(s):  
Clinical Implications ◽  
Phonological System

This paper examines the credibility of deviant articulation as a less mature phonological system and as an individual phonological system with its own rules. Evidence is presented suggesting that both types of deviant phonological systems may occur in the articulatory defective population. The clinical implications of each type of deviant system are presented.

Communicative Performance of Adolescents with Severe Speech Impairment

1989 ◽  
Vol 54 (3) ◽  
pp. 403-421 ◽  
Author(s):  
Beth M. Dalton ◽  
Jan L. Bedrosian
Keyword(s):  
Data Analysis ◽  
Peer Interactions ◽  
Consistent Pattern ◽  
Clinical Implications ◽  
Speech Impairment ◽  
Communication Mode ◽  
Mode Function ◽  
Communicative Performance ◽  
Therapy Room ◽  
Communication Board

The communicative performance of 4 preoperational-level adolescents, using limited speech, gestures, and communication board techniques, was examined in a two-part investigation. In Part 1, each subject participated in an academic interaction with a teacher in a therapy room. Data were transcribed and coded for communication mode, function, and role. Two subjects were found to predominantly use the speech mode, while the remaining 2 predominantly used board and one other mode. The majority of productions consisted of responses to requests, and the initiator role was infrequently occupied. These findings were similar to those reported in previous investigations conducted in classroom settings. In Part 2, another examination of the communicative performance of these subjects was conducted in spontaneous interactions involving speaking and nonspeaking peers in a therapy room. Using the same data analysis procedures, gesture and speech modes predominated for 3 of the subjects in the nonspeaking peer interactions. The remaining subject exhibited minimal interaction. No consistent pattern of mode usage was exhibited across the speaking peer interactions. In the nonspeaking peer interactions, requests predominated. In contrast, a variety of communication functions was exhibited in the speaking peer interactions. Both the initiator and the maintainer roles were occupied in the majority of interactions. Pertinent variables and clinical implications are discussed.

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