Disorders of Language, Speech and Swallowing

Author(s): Steven Flanagan, MD

Originally published:11/10/2011

Last updated:09/18/2015

1. DISEASE/DISORDER:

Definition

Aphasia is a disturbance of any or all of the skills, associations and habits of spoken and written language caused by injury to cerebral areas that are specialized for this function.

Apraxia of speech is a disorder of carrying out or learning complex speech movements not accountable by disturbances in strength, coordination, sensation, comprehension or attention. Verbal apraxia is manifested by limited number of consonants, and vowels, articulation errors and problems sequencing movements in rapid succession.

Dysarthria is a group of speech disorders caused by muscle paralysis, weakness or incoordination manifested by impairments in articulation, rate of speech production, respiratory coordination and/or laryngeal control, rather than language content.

Dysphagia is a disorder of swallowing that impairs the speed and/or safe delivery of food materials from the point of entry into the mouth into the upper portion of the esophagus.

Etiology

  1. Ischemia
  2. Trauma
  3. Hypoxia
  4. Toxic/metabolic
  5. Neoplasm
  6. Congenital
  7. Degenerative
  8. Developmental

Epidemiology including risk factors and primary prevention

The overall prevalence of communication disorders in the United States is 14 million.1Approximately 100,000 individuals acquire aphasia annually.2 Incidence of aphasia varies by etiology and is most commonly associated with stroke. The incidence of aphasia following first-time stroke is approximately 35%, but is associated by stroke location (dominant hemisphere) and neurological severity. The true incidence of dysphagia is unknown, although it has been estimated that up to 60% of long-term health care facility residents and 30% of general medical inpatient services have dysphagia.1,2

Patho-anatomy/physiology

Aphasia results from injury to specific areas of the dominant cerebral hemisphere with clinical manifestations dependent on location and extent of neural damage. Non-dominant language dysfunction is related toimpairments in prosody and higher level cognition including unawareness of social cues, humor and body language, and inappropriate utterances.

Anatomical lesions vary in cases of speech apraxia, but frequently involve the left hemisphere insula.

Dysarthrias are caused by both upper and lower motor neuron injury, with clinical manifestations dependent on the location and extent of neural damage.

Dysphagia results from numerous causes, including lesions of thecentral and peripheral nervous system, trauma and structural abnormalities impacting the anatomical substrates involved in swallowing.

Disease progression including natural history, disease phases or stages, disease trajectory (clinical features and presentation over time)

Disorders of language, speech and swallow resulting from stroke, trauma, and anoxia tend to improve over time. Progression occurring from other conditions is variable and depends on disease state and progression as well as effects of treatment (eg, radiation for neoplasms).

2. ESSENTIALS OF ASSESSMENT

History

See Etiology, above.

Physical examination

Aphasia: Definitive classification of aphasia is achieved through formalized assessment tools. Bedside examinations focusing on fluency, comprehension, ability to repeat sentences, reading and writing can help delineate different aphasia subtypes.

  1. Broca’s aphasia: Non-fluent, impaired repetition, intact comprehension;
  2. Transcortical motor aphasia: Non-fluent, intact repetition, intact comprehension;
  3. Global aphasia: Non-fluent, impaired repetition, impaired comprehension;
  4. Wernicke aphasia: Fluent, impaired repetition, impaired comprehension;
  5. Conduction aphasia: Fluent, impaired repetition, relatively intact comprehension;
  6. Transcortical sensory aphasia: Fluent, intact repetition, impaired comprehension;
  7. Aphemia (pure word mutism): Impaired speech production with retained comprehension and ability to write;
  8. Pure word deafness: Loss of auditory comprehension and repetition without abnormalities of naming, reading or writing;
  9. Alexia without agraphia: Acquired inability to read, variable naming impairment with retained ability to write.
  10. Anomic: Fluent, intact repetition, impaired naming.

Non-dominant hemisphere language disorders: Bedside examination

Dysarthria: Functional assessment of the larynx, respiration, vocal articulations and the pharynx.

  1. Spastic: Hypertonic muscles with decreased range of motion, reduced speed of muscle excursion with strained-strangled vocal quality;
  2. Hyperkinetic: Altered rhythm and rate of oromotor movements with involuntary muscle actions; variability in muscle tone with altered pitch and volume control, stress, rate, phoneme duration and sudden respiratory inhalations and exhalations;
  3. Hypokinetic: Oromotor rigidity, decreased range of motion and force of movement with variable movement velocity manifested by decreased range of pitch and volume, reduced stress, festinating speech and a hoarse/breathy vocal quality;
  4. Ataxic: Articulatory and prosodic impairments manifested by imprecise articulation of vowels and consonants, articulatory breakdowns, excessive and equal stress, prolongation of phonemes and inter-word intervals, decreased rate of speech, mono-pitch and mono-loudness, and harsh vocal quality;
  5. Flaccid: Flaccid oromotor muscles and fasciculations. Detailed cranial nerve evaluation is essential ; often manifested by breathiness, audible inspirations, hypernasal vocal quality, decreased phrase length, consonant imprecision, vocal harshness and reduced range of pitch and volume;
  6. Mixed: Variable combination of above.

Apraxia: Clinical features include effortful, groping or trial and error attempts at speech, dysprosody, inconsistent articulation errors and difficulty initiating speech.

Dysphagia: Bedside evaluation includes assessment of oral sensation, oral reflexes, postural abnormalities, motor assessment of face, lips, tongue, palate and larynx, level of arousal, ability to follow directions and management of saliva. Bedside screening tools useful to physicians include the 3-oz water swallow test or the Toronto Bedside Swallowing screening test (TOR-BSST)

Laboratory studies

Dysphagia:

  1. Modified barium swallow (MBS) or videofluoroscopic swallowing study (VFSS): evaluates swallowing by radiographically visualizing swallow using various consistencies of barium.
  2. Fiberoptic endoscopic evaluation of swallowing (FEES) directly visualizes laryngeal and pharyngeal structures involved in swallowing. It is portable , lacks of radiation, visualizes secretions, and detectsing structural abnormalities of the pharynx and larynx but does not assess the oral stage of swallowing or the cervical esophagus.
  3. Manometry determines the pressures and relative timing of pharyngeal contraction and relaxation of the upper esophageal sphincter during swallowing.

Supplemental assessment tools

Aphasia

  1. Boston Diagnostic Examination of Aphasia
  2. Western Aphasia Battery
  3. Communications Activities of Daily Living
  4. Porch Index of Communication Ability

Dysarthria

  1. Assessment of Intelligibility of Dysarthric Speech is a standardized assessment of dysarthria severity that incorporates measures of speech intelligibility, overall speech rate of intelligible speech and a ratio of communication efficiency.
  2. Frenchay Dysarthria Assessment is a standardized assessment of reflexive, respiratory, articulatory, resonatory and phonatory mechanism of speech
  3. Fisher-Logemann Test of Articulation Competence is used primarily in pediatrics; it involves testing that permits generation of an articulation profile that can be analyzed according to the nature of altered speech production within the context of developmental articulations and phonation errors.

Early predictions of outcomes

Severity of initial language impairment is predictive of neurological and functional recovery in certain central neurological disorders.

Professional Issues

Dysphagia: Placement of gastrostomy tubes provides a means to deliver nutrition, hydration and enteral medications to patients with dysphagia and may reduce the risk of aspiration. Gastrostomies are often recommended following acute neurological injuries and in most cases can be removed as recovery ensues. Patients with progressive disorders often require permanent placement and may be opposed by patients or their health-care proxies, resulting in ethical and legal issues regarding implantation and potential removal. The pros and cons of alternatives to gastrostomies, such as continued unsafe oral intake, intravenous supplementation, cuffed tracheostomy or surgery (eg, laryngeal diversion) should be discussed with patients or their health-care proxies.

3. REHABILITATION MANAGEMENT AND TREATMENTS

Available or current treatment guidelines

Aphasia: Speech-language therapy (SLT) to maximize communication skills through verbalizations or compensatory means (eg, communication boards, augmentative communication) is standard practice. Utilization of melodic intonation to “sing” words may be useful. Review of literature tends to support effectiveness of SLT with more intensive therapy as possibly more effective than conventional SLT. Pharmacological interventions with catecholiminergic, dopaminergic, and acetylcholinergic agonists as well as piracetam and memantine may be effective although evidence is inconclusive.

Dysarthria: Management focuses on maximizing strength and coordination of oromotor musculature. Behavioral approaches are used to optimize vocal cord adduction, improve posture, enhance breath support, improve strength and coordination of muscles involved in speech and improve prosody. Instrumental approaches used to improve speech include biofeedback and timers or pacers to control rate. Invasive procedures such as neurotoxins to treat spastic muscles, palatal lifts,and injections to medialize paralyzed vocal cords can be used in selected cases. Augmentative communication devices are used when other strategies fail to improve intelligibility.

Dysphagia: Compensatory strategies include changing head and/or body position to reduce risk of aspiration (eg, chin tuck, head tilt, head rotated); enhancing sensory input of food materials; exercises to improve swallowing (supraglottic, super-supraglottic, effortful, Mendelsohn exercises, tongue hold, double swallow); lingual exercises; head lifting exercises; changes in food consistencies (ie, thickening liquids or changing size/consistency of solids); devices such as palatal lifts and vocal cord medialization in cases of vocal cord paralysis to reduce risk of aspirations. Gastrostomy/nasogastric tube/jejunostomy may be needed in cases where aspiration risk cannot be reduced and/or nutritional needs cannot otherwise be met. Effectiveness of neuromuscular electrical stimulation remains unproven.

4. CUTTING EDGE/EMERGING AND UNIQUE CONCEPTS AND PRACTICE

Cutting edge concepts and practice

Aphasia: repetitive low frequency transcranial magnetic stimulation to the non-dominant hemisphere injury may improve non-fluent aphasia in which only verbalizations are permitted in communication (ie, no gestural or written communication).3

5. GAPS IN THE EVIDENCE-BASED KNOWLEDGE

Gaps in the evidence-based knowledge

Limited evidence supports the effectiveness of speech-language therapy for people with poststroke aphasia, with more intensive therapy likely more effective than conventional approaches. There is a paucity of evidence supporting any one aphasia treatment technique over another.4There is insufficient evidence to support or refute the effectiveness of speech language therapy for treatment of apraxia of speech.5,6 There is currently insufficient knowledge regarding the effectiveness of electrical stimulation on dysphagia.

REFERENCES

  1. National Institutes of Health: National Institute on Deafness and Other Communication Disorders: statistics and epidemiology – statistics on voice, speech, and language. Retrieved January 2, 2011 from http://www.nidcd.nih.gov/health/statistics/vsl.asp. Accessed June 11, 2011.
  2. Ellis C, Dismuke C, Edwards K. Longitudinal trends in aphasia in the United States. Neurorehabilitation. 2010;27(4):327-333.
  3. Groher ME. The prevalence of swallowing disorders in two teaching hospitals. Dysphagia. 1986;1:3-6.
  4. Croghan JE, Burke EM, Caplan S, et al. Pilot study of 12-month outcomes of nursing home patients with aspiration on videofluoroscopy. Dysphagia. 1994;9:141-146.
  5. Kelly H, Brady MC, Enderby P. Speech and language therapy for aphasia following stroke. Cochrane Database Syst Rev. 2010; May 12(5):CD000425. Accessed June 11, 2011.
  6. West C, Hesketh A, Vail A, Bowen A. Interventions for apraxia of speech following stroke. Cochrane Database Syst Rev. 2005;Oct 19(4):CD004298. Accessed June 11, 2011.

Original Version of Topic

Steven Flanagan, MD. Disorders of Consciousness. 2011/11/10.

Author Disclosures

STEVEN FLANAGAN, MD
Spring Publishing: Royalties from text book

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