Higher cortical function: Language Flashcards
What is language?
A systematic means of communication using conventionalised sounds, gestures and marks
What is speech?
Speech is an expression of thoughts in spoken words.
Speech is the final motor step in oral expression of language.
What is phonation?
Phonation involves sound and volume.
What do the areas involved in language originate from?
The areas involved in language originate in the motor/sensory cortex.
What are the most important areas/tracts involved in language?
- Inferior frontal gyrus (Broca’s area)
- Superior temporal gyrus (Wernicke’s area)
- Corticobulbar tract: descending fibres which go down to the brain stem and innervate various nerves important in speech production.
Are more people right or left handed, and which cerebral hemisphere has dominance?
More people are right-handed, with left cerebral dominance.
Approximately 90% of people are right-handed, and approximately 95% of them process language in the left cerebral hemisphere.
Where does speech start from anatomically?
In the speech generating cortex.
Where does modulatory input for speech come from?
Modulatory input comes from the corticobulbar pathway, basal ganglia, cerebellum, and auditory recognition areas of the brain.
What are other anatomical components involved in speech?
- Tongue and other muscles involved
- Larynx - a voice generator
- Oropharynx – a voice modulator.
Which cranial nerves have input into speech?
- 10th nerve (supplies the larynx)
- 12th nerve (supplies the tongue).
What is the term for a problem with phonation?
Problem = Dysphonia
Absence = Aphonia.
What is the term for a problem with articulation of speech?
Problem = Dysarthria
Absence = Anarthria.
What is the term for a problem with comprehension and production of language?
Problem = Dysphasia
Absence = Aphasia.
What are the key elements of language?
- Comprehension
- Repetition
- Fluency
- Naming
- Reading
- Writing.
What should be tested for when a language disorder is detected?
All elements of language should be tested when a language disorder is suspected.
What are dysphasia/aphasia syndromes characterized by?
Several dysphasia/aphasia syndromes, each characterized by a specific form of language impairment.
What are the types of dysphasia?
Expressive and receptive.
What are the signs of expressive aphasia (dysphasia)?
- Paucity of spontaneous speech
- Non-fluent, agrammatical, telegraphic nature of the speech
- Language comprehension is intact
- Patients are unable to write normally or to repeat
- The patient is typically aware of the disorder and frustrated by it.
Cause: Lesion in the inferior frontal gyrus in the dominant (usually left) hemisphere.
What are the signs of receptive aphasia (dysphasia)?
- Patient’s comprehension and repetition are impaired
- Speech is fluent but does not make sense
- A large volume of language is produced but lacks meaning
- Comprehension of written language is impaired
- The patient cannot follow commands but can imitate actions when prompted.
Cause: Lesion in the superior temporal gyrus in the dominant (left) hemisphere.
What are the other types of aphasia?
- Global aphasia
- Conduction aphasia
- Transcortical aphasia
- Anomic aphasia.
What is the differential diagnosis for aphasia?
Dysarthria may be difficult to distinguish from aphasia, as it always spares oral and written language comprehension and written expression.
What is dysphonia?
A disorder of the voice characterized by an inability to produce sounds properly using the vocal cords.
What is aphonia?
Aphonia is the inability to produce phonation.
What are the causes of dysphonia/aphonia?
- Structural/Neoplastic: Cysts, Polyps, Nodules, Carcinoma
- Inflammatory: Allergy, Infections, Reflux, Smoking
- Neuromuscular: Multiple Sclerosis, Myasthenia Gravis, Parkinson’s disease, Spasmodic Dysphonia, Nerve injury
- Systemic Diseases: Acromegaly, Amyloidosis, Hypothyroidism, Sarcoidosis
- Other: Psychogenic, Stress, Vocal strain.
