Human Communication PDF

HUMAN COMMUNICATION Introduction The use of language has been a most remarkable human accomplishment. It is used to reconstruct the past, represent the present, and consider the future. The need to communicate has necessitated the invention of many sophisticated systems of speech, gesture, and writi...

HUMAN COMMUNICATION Introduction The use of language has been a most remarkable human accomplishment. It is used to reconstruct the past, represent the present, and consider the future. The need to communicate has necessitated the invention of many sophisticated systems of speech, gesture, and writing in order to relay ideas. Through language we learn about things we have never experienced and also impart our own experiences. Language plays a role in solving problems, expressing feelings, and relating with other human beings. Language is an organized set of symbols used for communication. Speech is the oral manifestation of language, as writing is the graphic form, and sign language, the gestural form. Language system is a conglomeration of different components that function in a coordinated and integrated fashion in order to communicate. It comprises different anatomical structures. Without a complete language systems or presence of complete language system with faulty components, language does not develop properly. The development of language in turn depends on the ability to organize and symbolize concepts. This cognitive and conceptual development is based on sensory experiences acquired through the interaction with the environment. The development of language is a complex process. Even, in the presence of an intact conceptual and cognitive system, one must perceive, retain, and produce a variety of speech sound requiring precise and coordinated activity of the lips, tongue, palate, larynx, and respiratory system. One must sequence sound to form words, remember and order the word in an accepted and meaningful way, use syntax appropriate to the intended meaning, inflect and stress word correctly to portray correct meaning and attitudes, and then monitor the production through sensory channels. HUMAN COMMUNICATION Human communication is often described as a well-coordinated, timed, multidimensional group of processes used to share thoughts, ideas, and emotions. Human communication involves the exchange of information and ideas through various processes commonly referred to as speech, language, cognition, and hearing. Though (the pattern/means of communication has evolved tremendously following technological advancements, human communication has retained its value because of its practical nature in the transfer of meaningful information amongst individuals (ie the essence of communication remains the same). The components of human communication are dynamic and multidimensional and are continuously influenced by physiological, psychological, and environmental factors. Although complex, the components of communication can be simplified into four-step components: Encoding: the speaker creates the message in his or her mind Transmission (medium): the speaker sends the message (sound is not transmitted in a vacuum) Decoding/Reception: the listener receives the message and breaks down the message. Feedback: how the message is understood. PROCESSES OF HUMAN COMMUNICATION 1. SPEECH Speech is the system that produces individual sounds, which, when placed together, develop meaningful messages. It is the verbal means of communication often thought of as the motor vehicle for message delivery. Speech production requires multiple physiological systems working together to create an intelligible message. The five systems comprising speech production include respiration, phonation, resonation, articulation, and hearing. Although each system works concurrently with each other to achieve the result of the speech, it is often easier to understand the complexity of the systems by reviewing them as separate entities. i. Respiration Two forms of respiration are recognized: chemical and mechanical. Chemical respiration is concerned with the exchange of oxygen and carbon dioxide to and from the blood, whereas mechanical respiration (or ventilation) is concerned with the tidal movement of air in and out of the lungs. For speech production, mechanical ventilation will be the primary focus. To produce sound, an energy source is needed to initiate the process. For speech, this energy source is the respiratory system, causing air pressure variations that result in airflow out of the respiratory tract and into the vocal tract. During inhalation, the diaphragm contracts and lowers allowing the thoracic cavity to expand and the lungs to fill with air. This causes a low-pressure gradient, allowing the air to rush into the lungs. The pressure then equalizes as air is sustained in the lungs. Exhalation is the more passive mechanism of the inhalation/ exhalation process. Exhalation causes relaxation of the diaphragm causing it to return to its normal position and shape. This in turn causes an increased pressure gradient compared to outside the lungs, which ultimately results in air flow out of the lung cavity. The entire process of breathing (inspiration and expiration) is known as one respiratory cycle. At rest, this takes place 12 to 15 times a minute. Speech production occurs upon exhalation. During speech production, the time for inhalation is often reduced while the exhalation time is increased. ii. Phonation The phonatory process, or voicing, occurs when air is expelled from the lungs through the glottis (space between the vocal folds). As air passes through this area, the vocal folds begin oscillating. This oscillation causes vibration, which is often referred to as the engine of the voicing mechanism. The oscillation of the vocal folds serves to modulate the pressure and flow of the air through the larynx. This air flow is modulated and is the main source of voiced sounds. A normal voice is best described as the product of a controlled exhalation of air, steady maintenance of subglottic air pressures, and delicately balanced vocal folds movement. Any perturbation to this complex process can result in a perceived vocal impairment. iii. Resonation The raw vocal tone is modified and amplified by resonance within the pharyngeal, oral, and nasal cavities, which are referred to collectively as the vocal tract. The innumerable configurations of the shape of the vocal tract provide the human voice with a tremendous range of variation in perceived quality. Following transit through the larynx, the air is modulated by (a) changing the tension of the pharyngeal walls; (b) raising or depressing the larynx; (c) modifying the position of the jaw, tongue, and lips; and (d) occluding or lowering the soft palate.  iv. Articulation The final production of sound occurs as air is expelled through and manipulated within the oral cavity by the movements of the lips, teeth, and tongue. Coordinated actions of the tongue, lips, jaw, and soft palate regulate the air stream and produce the meaningful sounds of speech called phonemes. These structures, often referred to as articulators, relax, compress, or momentarily stop the air stream in varied ways to produce specific vowels or consonants. The addition or elimination of a voicing component from the larynx, during sound production, dictates whether a consonant is voiced or voiceless. v. Neural Control Motor control for respiration, phonation, resonation, and articulation requires complex neural networking, regulation, and monitoring of muscle activity of both the central nervous system and the peripheral nervous system. Many of the speech systems and musculature used for speech production are also used for oropharyngeal swallowing and mastication. The central nervous system and peripheral nervous system are the primary controls for neural networking. 2. LANGUAGE Language may be defined as an arbitrary system of signs or symbols used according to prescribed rules to convey meaning within a linguistic community. Language forms the set of rules shared by communicators consisting of morphology, syntax, semantics, and pragmatics. I. MORPHOLOGY The study of how words are formed, and their relationship to other words in the same language. II. SEMANTICS A branch of language studies concerned with the relationship between words and their meanings. III. SYNTAX The order or arrangement of words and phrases to form proper sentences. IV. PRAGMATISM A field in linguistics is concerned with what a speaker implies, and a listener infers based on contributing factors like situational context, the individuals’ mental state, the preceding dialogue, and other elements.  3. COGNITION Cognition refers to the mental processes by which one recognizes, manipulates, and exchanges information to better understand and make sense of the world. Cognition gives rise to the thoughts and ideas for which one uses speech and language. COMMUNICATION PATHOLOGY Communication could be accomplished through facial expression, body movement, and gestures. These nonverbal components are of great importance in the communication process. Information about attitudes and feelings is portrayed in posture, gaze, and voice inflection. If oral or written communication is disrupted, facial expression and body movement may be the only means of communication. On the other hand, individuals with severe neurological disorder may not be able to project intended facial expression and body movement for communication. As physical therapists, it is not impossible to encounter individuals that represent the whole spectrum of communication disorders in degrees and types. The disorders may be results of disruption of individual or combinations of the above-described aspects of communication through developmental or acquired disorders. It is vitally important that the physiotherapist understands not only how to communicate best with these clients but also how physiotherapy can assist in reversing or preventing the development and restoring communication. Disorder of speech, hearing, language and cognition each requires a different approach. Misdiagnosis of the nature of the disorder not only disrupts appropriate interactions but also promotes emotional maladjustment and motivational decline. A pathologic condition that affects any one of the organs involved in the process of speech or language influences the total final product. 1. Frequently, the pathologic condition often is limited to a single speech or language component, and the dysfunction can be detected in only one specific parameter such as an isolated (speech) or articulation impairment. 2. More commonly, however, the pathologic condition of a single organ influences other elements of the communication process in ways that are predictable when one considers the integrated nature of speech and language. For example, severe obstructive pulmonary disease does not just impair the respiratory support for speech but results in alterations in  vocal pitch, vocal intensity, and phrasing or prosody, as the speaker compensates for an impaired ability to sustain airflow. 3. Certain disease states, involving organs that are not directly involved in speech or language, can affect the final vocal product in a secondary manner. For example, some endocrine disorders, such as hypothyroidism, can influence voice quality as an isolated component of speech. It can also lead to language confusion and impaired memory. Because of the complexity and interactive nature of the speech and language processes, whenever one evaluates or treats a patient with a communication disorder, some considerations must be given to overall human physiology, as well as to the dynamics of speech and language systems. Many professionals including audiologists, physiatrists, and otolaryngologists contribute to the assessment and treatment of communication. Speech-language pathologists have the specialty training in the communication impairments and are credentialed to assess, treat, and manage the communication disorders with the ultimate goal of developing and maintaining a functional communicative status for individuals. MOTOR SPEECH DISORDERS A) Dysarthria Dysarthrias are a group of motor speech disorders characterized by slow, weak, imprecise, or uncoordinated movements of speech musculature. Rather than a single neurological disorder, dysarthrias vary along several different dimensions. As stated above, the neuroanatomical site of a lesion causing dysarthria can be one or a combination of the cerebrum, cerebellum, brainstem, and cranial nerves. Dysarthria can be a symptom of a neurological disease process with a constellation of other symptoms, or it can stand alone with a disease.  TBI (approximately1/3)  Parkinson’s disease (50 to 90%)  Amyotrophic Lateral Sclerosis  Dysarthria can be classified by the time of onset, site of lesion, and etiology; however, the most widely used classification was first described by Darley et al. (1975). This is often referred to as the Mayo Clinic Classification System with each type representing a perceived and distinguishable grouping of speech characteristics with a presumed underlying pathophysiology or locus of lesion. The following summarizes the major types of dysarthria, their primary distinguishing perceptual attribute, and their presumed underlying localization and distinguishable deficit. 1. Flaccid Dysarthria Description Flaccid dysarthria is due to weakness in cranial or spinal column innervations to the speech system. Its specific characteristics depend on which nerve is involved.  Nerves affecting articulation include trigeminal, facial, or hypoglossal.  The vagus nerve contributes to voice and resonation primarily seen with breathy, hoarse, and diplophonic speech.  Spinal respiratory nerves can also be affected with deficits in breath patterning for speech, often causing production of short phrases. Most common speech characteristics include: i. Hypernasality (Hypernasal speech is a disorder that causes abnormal resonance in a human's voice due to increased airflow through the nose during speech.) ii. Breathiness (the quality of the speaking voice being accompanied by an audible emission of breath) iii. Diplophonia (a condition in which the voice simultaneously produces two sounds of different pitch) iv. Nasal emission v. Audible inspiration (stridor)  vi. Short phrases vii. Rapid deterioration and recovery with rest. NOTE: Brainstem stroke or brain injury is a common cause of flaccid dysarthria. 2. Spastic Dysarthria Spastic (spasm) dysarthria is usually associated with bilateral lesions of upper motor neuron pathways that innervate the relevant cranial nerve and spinal nerve. Its distinguishable characteristics are attributed to spasticity. Features:  Harsh, strained vocal quality,  slow speech rate,  pitch breaks,  Variable loudness. All speech systems are typically affected with this classification. 3. Ataxic Dysarthria Ataxic (ataxia) dysarthria is associated with lesion’s disturbances of the cerebellum or its controls. As it is known for its incoordination as a characteristic, individuals are perceived with articulation and prosodic feature disturbances. FEATURES  Irregular articulatory breakdowns,  Distorted vowels,  Inappropriate variations in pitch, loudness, and stress often are the classic features. This type of dysarthria has been coined with the term “drunken speech.” NOTE: Ataxic dysarthria is often a result of cerebellar stroke or spinocerebellar ataxia. 4. Hypokinetic Dysarthria Hypokinetic (hypokinesia) dysarthria is associated with basal ganglia control of the central nervous system. Its features are mostly related to reduce range of motion and rigidity. Features Reduced loudness, short rushes of speech, breathy-tight dysphonia, and monoloudness and monopitch are notable characteristics. Often dysfluency and word repetition are reported. Parkinson’s disease and its syndromes are the most noted disorder for hypokinetic dysarthria. 5. Hyperkinetic Dysarthria Hyperkinetic (hyperkinesia) dysarthria is also associated with basal ganglia control; however, unlike hypokinetic dysarthrias, it is distinguished by abnormal involuntary movements that affect the intended speech movements. It is classified in many of the movement disorders and subcategorized into slow and fast hyperkinetic dysarthrias. Slow hyperkinetic dysarthria includes dystonia (neurological disorder associated with prolonged repetitive contractions of muscles resulting in jerky, twisting movements) and athetosis (involuntary struggling movements of the limbs usually bilateral and symmetrical, predominantly affecting the extremities), Fast hyperkinetic dysarthria includes tic (sudden, non-rhythmic motor movement) and chorea. They may affect any of the speech systems and area usually distinguished by unpredictable variability in voice and articulation. Features:  Distorted vowels  Excess loudness variations,  Sudden forced inspiration/expiration,  Voice stoppages/arrests,  Transient breathiness,  Intermittent hypernasality,  Inappropriate vocal noises. NOTE Etiologies for hyperkinetic include Huntington’s chorea, Tourette’s syndrome, cerebral palsy, and side effects of neuroleptic drugs. 6. Unilateral Upper Motor Neuron Dysarthria This dysarthria has an anatomical rather than a pathophysiological label. It typically results from stroke affecting upper neuron pathways. Damage is unilateral; severity usually is rarely worse than mild to moderate. Often its characteristics overlap with flaccid, spastic, or ataxic dysarthrias. 7. Mixed Dysarthria Mixed dysarthria reflects combinations of two or more of the single dysarthria types. It occurs more frequently than any single dysarthria type. A common diagnosis involving mixed dysarthria is amyotrophic lateral sclerosis, which, in advanced stages, has features of both flaccid and spastic dysarthrias. Treatment Considerations An overall goal for the treatment of dysarthria is to improve functional communication for the patient. Generally, treatment goals can vary with the severity of the speech impairment and the overall medical disorder. MANAGEMENT/TREATMENT A) For severely involved speakers, whose intelligibility is so poor that they are unable to communicate verbally in some or all situations, the general goal of treatment involves establishing an immediate functional means of communication. This may include the use of augmentative approaches. The term communication augmentation refers to any device designed to augment, supplement, or replace verbal communication for someone who is not an independent verbal communicator. These augmentative or alternative communication (AAC) systems can be as low tech as writing or communication boards or higher tech such as talk-back switches or computer-based speech synthesis. The selection of an appropriate augmentation system requires a thorough evaluation of the individual’s communication needs. To determine an individual’s needs, the clinician needs to consider the patient’s physical and cognitive capabilities, including cognition, language, memory, physical control, vision, hearing, and overall medical condition. This assessment may require additional co-evaluators, such as an occupational therapist or a rehabilitation engineer. Once the individual’s capabilities have been ascertained, augmentative system components can be selected, and appropriate system modifications can be made. B) For those moderately involved speakers who can use speech as their primary means of communication but whose intelligibility is compromised, the general goal of treatment involves improving intelligibility (able to be understood; comprehensible). Use of compensatory strategies with speech production or augmentative systems is common. Achieving compensated intelligibility may take a variety of forms, depending on the speaker and the nature of the underlying impairment. i. For some with greater involvement, use of an alphabet supplementation system, in which they point to the first letter of each word as they say the word, assists in the transition to intelligible speech. For others, the treatment involves an attempt to decrease the impairment by exercises that will improve performance on selected aspects of speech production. For example, exercises may involve developing more adequate respiratory support for speech or training to establish an appropriate speech rate. ii. For the mildly involved dysarthric speaker whose speech is characterized as intelligible but less efficient and less natural than normal, treatment planning should consider the patient’s needs in communication within his or her home or job setting. For some speakers, these mild reductions in speech efficiency pose no problems. For others, however, treatment is warranted. The general goals of treatment for dysarthric people with mild disabilities include maximizing communication efficiency while maintaining intelligibility and maximizing speech naturalness. Maximizing naturalness is accomplished by teaching appropriate phrasing, stressing patterning, and intonation. B) Head and Neck Cancer The diagnosis of head and neck cancer often presents with speech and/or swallowing impairments. The location of the malignancy often dictates the speech impairment being phonatory, resonance, articulatory, or a combination of the three. Treatment of the disease can be a sole modality such as surgery or radiation therapy or multiple modalities, including surgery, irradiation, and chemotherapy. Treatment is focused on organ preservation with the goal of maintaining function. This type of treatment is often recommended for tumors of the tongue, oral cavity, tonsil, base of tongue, and pharynx and larynx (as these play critical roles in speech production thus total removal may be fatal). Depending on tumor size, spread of disease, and nodal involvement, the treatment often involves radiation with or without chemotherapy. Often surgical intervention is needed with advanced disease or recurring disease. This may involve removal of the larynx alone or with other organs (total laryngectomy). With loss of the voicing component for speech production, there is an obvious need for speech rehabilitation. Several options for speaking are available to post-laryngectomy patients including artificial larynx, tracheal esophageal puncture, a voice restoration procedure. Artificial larynx uses or electro-larynx offers individuals the opportunity to speak within days of surgery. C. Fluency Fluency disorders are characterized by a disruption in the ease and flow of connected speech. The most common and well-known type of fluency disorder is stuttering. Stuttering is a very complex, dynamic, and somewhat controversial disorder in that theories and opinions abound regarding etiology, diagnosis, and treatment. Theories regarding underlying cause include genetic, cognitive, psycholinguistic, neuromuscular, as well as multifactorial. Primary Characteristics of stuttering include:  Blocks (absence of sound),  Repetitions (of sounds or words), and/or prolonged sounds. Secondary behaviors often observed include:  Struggle (body movement, eye blinks, lip/jaw tremors) and  Avoidance of sounds, words, conversation partners or environments that trigger the dysfluency. The evaluating clinician must be very cautious with diagnosis for several reasons. One, stuttering resolves in 75% to 90% of small children who begin to stutter. Additionally, there is a spectrum of normal dysfluency that is reactive to environmental pressures but is not consistent with a stuttering diagnosis. There is no known standard treatment for stuttering. However, common approaches include environmental modifications, desensitization, fluency-shaping techniques (i.e., easy onset, continuous phonation, auditory/ visual feedback), and possibly psychological intervention. One component that is quite consistently included is counseling and support by the speech-language pathologist with the goal of changing the patient’s mindset from anticipating stuttering to anticipating fluency. Goals may vary from the absence of stuttering to reducing the severity and eliminating avoidance behaviors to improve the quality and effectiveness of overall communication. AUDIOLOGY  Hearing is the ability to perceive sounds.  Sound occurs over a wide spectrum of frequencies.  The human ear is sensitive to a frequency band within that spectrum expressed in decibels (dB).  Frequencies capable of being heard by humans are called audio or sonic.  The range is typically considered to be between 20 Hz and 20, 000 Hz (Hertz). Frequencies higher than audio are referred to as ultrasonic, while frequencies below audio are referred to as infrasonic.  Loss of the ability to hear sound frequencies in the normal range of hearing is called hearing impairment. AUDITORY PATHWAY  The auditory pathway comprises the external ear, the middle ear and the inner ear, followed by the auditory nerve ending up in the auditory centres in the auditory cortex.  The external ear consists of the pinna, ear canal and eardrum. Sound travels down the ear canal, striking the eardrum and causing it to move or vibrate.  The middle ear is a space behind the eardrum that contains three small bones called ossicles.   This chain of tiny bones is connected to the eardrum at one end and to the oval window at the other end which connects to the inner ear.  Vibrations from the eardrum cause the ossicles to vibrate which, in turn, creates movement of the fluid in the inner ear.  Movement of the fluid in the inner ear, or cochlea, causes changes in tiny structures called hair cells.  This movement of the hair cells sends electric signals from the inner ear up the auditory nerve (also known as the hearing nerve) to the brain.  The brain then interprets these electrical signals as sound. HEARING LOSS There are three basic types of hearing loss: conductive hearing loss, sensorineural hearing loss and mixed hearing loss based on which part of the auditory system is damaged.  Conductive hearing loss Occurs when sound is not conducted efficiently through the external ear canal to the eardrum and the ossicles of the middle ear. This type of hearing loss usually involves a reduction in sound level or the ability to hear faint sounds and can be corrected medically or surgically.  Sensorineural hearing loss (SNHL) Occurs when there is damage to the inner ear (cochlea), or to the nerve pathways from the inner ear to the brain. Sensorineural hearing loss is the most common type of hearing loss and cannot be medically treated so far. Persons affected have difficulties in hearing faint sounds even when the speech is loud enough. Mixed Hearing Loss Combination of 1 & 2 above Possible Causes of hearing loss 1. Ear infections Hearing loss can be caused by viral, bacterial or parasitic infections. Middle ear infections are important causes of hearing impairment for many children in the world. For example, chronic suppurative otitis media is the commonest cause of hearing loss in children in developing countries. 2. Untreated infections during childhood The difficulty of access to health care facilities and other factors such as poor personal hygiene and overcrowding cause many children in low- and middle-income countries to become deaf or hard of hearing following infections such as meningitis, measles, viral encephalitis, chicken pox, influenza, mumps or other viral infections. In the in the sub-Saharan Sahelian region of Africa, so-called “meningitis belt” epidemics of meningococcal meningitis happen regularly, and many survivors are left with sensori-neural hearing loss and other neurological sequelae. 3. Congenital hearing loss The term congenital hearing loss means that hearing loss is present at birth. Congenital hearing loss can be caused by genetic or non-genetic (acquired) factors. Non-genetic factors that are known to cause congenital hearing loss are linked to pregnancy and birth delivery and include:  Maternal infections during pregnancy, such as rubella (German measles), Cytomegalovirus, or herpes simplex virus  Prematurity  Low birth weight  Cranio-facial abnormalities  Birth injuries  Toxins including certain drugs and alcohol consumed by the mother during pregnancy  Complications associated with severe jaundice in the newborn baby often due to maternal-fetal blood type incompatibility  Maternal diabetes   Lack of oxygen (anoxia)  Hearing loss from genetic defects can be present at birth or develop later in life. Most genetic hearing loss can be described as autosomal recessive or autosomal dominant, linked to X-chromosome or to mitochondrial inheritance patterns.  In autosomal recessive hearing loss, both parents carry the recessive gene and pass it along to the child. Marriages between cousins, especially first cousins, which occur in certain communities, favour this type of genetically inherited disorders.  Autosomal dominant hearing loss occurs when an abnormal gene from one parent can cause hearing loss even though the matching gene from the other parent is normal. Other genetically inherited syndromes such as Down syndrome, Usher syndrome, Treacher Collins syndrome, Crouzon syndrome, Alport syndrome and Waardenburg syndrome include hearing loss as part of the syndrome. 4. Injury/trauma Head injury, acoustic trauma, ear and brain tumors can induce a permanent sensori-neural hearing impairment. The auditory nerve is then not able to transfer signals to the brain. 5. Aging Aging contributes substantially to damage and deterioration of the peripheral and central auditory system. Age related loss of audition is called presbycusis. In humans, inner and outer hair cells present in the cochlea of the inner ear cannot self-reconstitute, therefore a loss of or damage to these cells is irreversible and causes permanent hearing impairment. Neural loss and strial loss may also be factors. 6 Exposure to prolonged or excessive noise Exposure to high levels of noise is the most common cause of hearing loss in adults but presbycusis, which is potentiated by noise has the highest prevalence in older adults. Exposure to excessive duration and intensity of noise causes progressive loss of outer and inner hair cells with damage and eventual death of the organ of Corti, ischemia of the inner ear, and increased metabolic activity leading to excessive reactive oxygen species (ROS) generation and lipid peroxidation. Exposure to high level of noise such as during loud concerts or use of headphones contribute to hearing loss. Noise is also a concern for soldiers who are exposed to noise bombardments, hunters exposed to rifle fire, pilots and industrial workers especially in developing countries where there is more likely to be lack of available protection and the legislation to enforce it. This type of hearing loss can be either transient (called temporary threshold shift) or permanent (called permanent threshold shift). With the latter, the part of the cochlea where hair cell death occurs initially is related to the noise frequency that causes it, partly due to direct mechanical damage. The over-stimulation of hair cells also causes excessive generation of free radicals, which may continue for some time after the initial trauma. 7 Medications and other chemicals that are toxic to the ear Certain medications are considered ototoxic as they may cause damage of hair cells in the inner ear. There are more than 200 known ototoxic medications (prescription and over-the counter) on the market today. These include medicines used to treat serious infections, cancer and heart disease. Hearing loss caused by these drugs is often dose dependent and with some drugs can sometimes be reversed when the drug therapy is discontinued (e.g. loop diuretics, quinine, salicylates). Sometimes, however, the damage is permanent. Ototoxic medications known to cause permanent damage include all commonly used aminoglycoside antibiotics, such as gentamicin (family history may increase susceptibility), streptomycin, amikacin, kanamycin and neomycin. They all affect the vestibular system (organ of balance) as well as the cochlea although streptomycin has a greater effect on the former and neomycin acts mainly on the latter. Cisplatin ototoxicity results from the production of reactive oxygen species (ROS) within the cochlea, overwhelming endogenous antioxidant mechanisms and causing irreversible free– radical-related apoptosis of cochlea outer hair cells, spiral ganglion cells, and the stria vascularis. Hearing loss is usually bilateral and irreversible, and is particularly severe in young children with neuroblastoma, CNS malignancies, and in adults with head and neck cancers, in which the base of the skull or brain may be irradiated. Medications known to cause temporary damage include salicylate pain relievers (aspirin, used for pain relief and to treat heart conditions), macrolide antibiotics such as erythromycin, quinine (to treat malaria), and loop diuretics – furosemide, bumetanide or ethacrynic acid (used to treat certain heart and kidney conditions). There is some evidence that excessive alcohol consumption may damage auditory centres in the brain and be ototoxic to the ear. 8.Nutritional Deficiency Causes Iodine deficiency is common in certain parts of the world and is one of the leading causes of preventable mental handicaps worldwide, including cretinism, in which hearing loss is a feature. Maternal hypothyroidism results in congenital hypothyroidism which is fully treatable if detected soon after birth. If it is untreated the child will develop cretinism. Hypothyroidism may potentiate presbycusis in the elderly. Diagnosis Early diagnosis and early intervention are essential to prevent further damage and provide adaptive therapies. CONDITIONS ASSOCIATED WITH COMMUNICATION IMPAIRMENTS 1. Communication Impairment after Right Hemisphere Damage Function of the Right Hemisphere (REFER FUNCTION OF HERMISPHERE) Communication impairments with right hemisphere–damaged patients largely relate to cognitive skills that impact communication. A cognitive-communication disorder is defined by the American Speech-Language-Hearing Association as a disorder that encompasses difficulty with any aspect of communication that is affected by disruption of cognition. Communication may be verbal or nonverbal and includes listening, speaking, gesturing, reading, and writing in all domains of language (phonologic, morphologic, syntactic, semantic, and pragmatic). Cognition includes cognitive processes and systems (e.g., attention, perception, memory, organization, executive function). Areas of function affected by cognitive impairments include behavioral self- regulation, social interaction, activities of daily living, learning and academic performance, and vocational performance. Skills affected by right hemisphere damage include attention, orientation, visual or auditory perceptual skills, memory, social communication (pragmatics), organization, reasoning and problem solving (executive functioning), safety awareness, and judgment. Some patients experience anosognosia, an unawareness of the problems experienced, which makes remediation more challenging. The pragmatic aspects, such as the lack of facial expression while speaking, failure to maintain eye contact, failure to use gesture, and lack of vocal inflection, have all been described in the patient with right hemisphere damage. These patients have difficulty in organizing information, and they fail to make use of context. Problems in interpreting incoming visual and auditory information, long known to be a right hemisphere function, make it difficult for these patients to get the main idea of discourse, leading to further frustration of friends and family. Assessment 1. Rice Evaluation of Communication Problems in Right Hemisphere Dysfunction Formal assessment tool for the systematic evaluation of the communication skills of the patient with right hemisphere damage. This test offers a rating system for the use of pragmatics, nonverbal skills such as eye contact and facial gestures, interpretation of metaphoric language, memory skills, writing, visual scanning and tracking, and analysis of conversation, including topic maintenance, verbosity, and reference. Approaches to treatment based on the analysis are presented. 2. Informal assessment tools for communication ability were described by West et al. Their screening battery includes exploration of basic language skills, an analysis of single-word responses to part-whole tasks, oral opposites, written opposites, oral analogies, and printed analogies. Other sections include the interpretation of idioms and proverbs, effects of imagery, and evaluation of the patient’s ability to appreciate humor. Clinicians frequently will gather a variety of subtests from different sources to assess areas of cognitive communication, including attention, memory, executive functioning, and visual-spatial skills. Understanding patient personality and functional status prior to neurologic injury is important; therefore, the interview of close friends or family members is a critical element in assessment. Treatment Treatment should concentrate on three broad areas as follows: 1. The communication specialist should develop tasks that help the patient attend to contextual cues to reduce verbosity and improve topic maintenance, retell stories in a fashion that highlights the main points, and produce language that follows a logical sequence. Although these tasks appear related to the impairment, no data support success or failure using such strategies. 2. Education of the patient’s family members on how the loss of pragmatic and affective languages can affect their perception of the patient’s personality is important. Rehabilitation successes in other areas will be diminished or lost if the patient’s family members do not understand the reasons for the adjustment to a new personality. 3. Many speech-language pathologists also address the cognitive processes that affect communication, such as attention, memory, executive functioning, and safety awareness/ judgment. They do this through tasks that are individualized to address. 2. Communication Impairment After Traumatic Brain Injury Patients with TBI will suffer some degree of cognitive-communication impairment. Those with mild TBI may not initially have symptoms. Instead, difficulties may develop over weeks or months and/or may be subtle and thus may be missed by medical personnel. Such symptoms include memory loss, poor attention/concentration, emotional irritability, easily getting lost or confused, and reduced speed of thinking. The moderate to severe TBI patients will have more evident deficits, usually from the beginning stages. These include Attention Concentration Distractibility Memory Speed of processing Confusion Perseveration Impulsiveness Language processing “Executive functions” The Rancho Los Amigos Scale (read about this critically)—Revised is a tool that describes recovery from TBI in terms of increasing arousal and responsiveness, with reducing confusion and inappropriateness. As such progress takes place, improved cognitive communication and language processing also develops. An interval scale from lowest function to highest is the means for scoring and is depicted in the following manner. Levels I, II, and III require total assistance.  Level I describe when the patient has no response to any type of stimuli—visual, auditory, proprioceptive, vestibular, or painful.  Level II is when generalized responses (such as increased respiratory rate, whole body movements) occur after the presentation of a stimulus.  Level III is when localized responses begin to emerge. For example, the patient will turn toward or away from a specific stimulus and may respond inconsistently to simple commands.  Level IV, the Confused Agitated: Maximal Assistance stage, the patient is more alert and engages in simple purposeful behavior (i.e., scratching an itch) but becomes easily agitated. Verbalizations often are incoherent and/or inappropriate, and attention is very brief.  Level V, the Confused, Inappropriate Non-Agitated: Maximal Assistance stage, the agitation reduces; however, it can be triggered easily during overstimulation. The person is generally not oriented and is unable to learn new information, Sustained attention is slightly longer, but goal-directed problem-solving or self-monitoring behavior is minimal to absent.  Level VI represents the Confused, Appropriate: Moderate Assistance stage, where orientation is inconsistent, attention to highly familiar tasks improves, and ability to use external memory aids with assistance emerges. New declarative learning and awareness of impairment tend to be severely impaired.  During level VII, the Automatic, Appropriate: Minimal Assistance for Daily Living Skills, carryover of new learning begins and ability to self-monitor and correct errors emerges. Executive functioning and social functioning are impaired, having a significant impact on function in home and community environments.  Level VIII is the Purposeful, Appropriate: Stand-By Assistance stage, where one can use assistive memory devices to recall functional information, attend to familiar tasks for at least an hour in distracting settings, learn new tasks, verbalize awareness of deficits but may not appreciate the impact and take appropriate corrective action. Depression or irritability may be present.  Level IX is the Purposeful, Appropriate: Stand-By Assistance of Request stage with more independent alternating attention, with heightened self-awareness and executive  functioning, and with standby assistance as needed for optimal success in challenging environments. Frustration tolerance may be low.  Level X, the Purposeful, Appropriate: Modified Independent stage, the patient may be able to multitask with breaks, independently complete tasks requiring high levels of executive functioning with extra time, and/or use compensatory strategies. Social behavior is appropriate. Frustration tolerance may be low when sick or fatigued. Recovery through the stages can happen quickly, in a matter of days or weeks, or happen over months. It is important to be constantly reevaluating the patient to determine current skills/deficits and modify treatment plan accordingly. The most pervasive cognitive- communication deficits with chronic TBI patients include memory, executive function, and social behavior. Working memory, the ability to hold and manipulate information in the mind over short periods of time, and declarative memory (e.g., stored facts, memory for past events, and memory for words), one type of long-term memory, are most affected. Implicit, or procedural, memory, which is the other form of long-term memory and includes habits, skills, and emotional associations, typically remains preserved. Executive functions affect focused attention, planning and organizing, problem solving, verbal reasoning, and metacognition. Social functioning includes emotion recognition, social knowledge, social performance, and execution of these integrated functions in real-time interactions. one of the more challenging aspects of rehabilitating individuals with TBI is the frequent presence of poor self-awareness, or insight. The patient often does not recognize or have an appreciation of the consequences of his or her deficits. This poses a safety risk and can impact patient participation in therapy. Assessment Assessment is according to practice guidelines for the assessment of persons with TBI published by the Academy of Neurologic Communication Disorders and Sciences (ANCDS) It is a complex system comprising the following: i. American Speech-Language and Hearing Association Functional Assessment of Communication Skills (ASHA-FACS)  ii. The Behavior Rating Inventory of Executive Function (BRIEF) iii. The CADL-2, the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) iv. The Test of Language Competence—Expanded (TLC) v. The Western Aphasia Battery (WAB). (PLEASE REFER THE ABOVE ASSESSMENT INSTRUMENTS). vi. In addition to these standardized tests are other multiple sources of information, including the person’s preinjury characteristics, stage of development and recovery, and communication-related demands of personally meaningful everyday activities. Based on how the deficits found impact the individual’s function in daily life, an individualized treatment plan will be developed. The Western Neuro Sensory Stimulation Profile (WNSSP) can be administered to monitor change in patients. This assessment can be repeated often to demonstrate progress toward increased motor and sensory responses. Treatment Treatment typically involves tasks that improve orientation and memory, help in developing selective attention and discrimination, and emphasize reasoning, executive functioning, and social functioning.