S3: Speech Flashcards
Cortical Speech Centers
Cortical Speech Centers
- receptive (Sensory)
Cortical Speech Centers
- Executive
- Broca’s area (area 44)
- Exner’s area (area 45)
Cortical Speech Centers
- Association
Language formulation area (area 37)
Subcortical association fibers
- connect various areas of cortex in the same hemisphere together and also communicate with corresponding cortical areas in the other hemisphere through the corpus callosum.
Peripheral NM Control of Speech
Peripheral NM Control of Speech
- Msucles
Phonation and articulation involve movements of the jaw, lips, tongue, palate, larynx, and the respiratory muscles.
Peripheral NM Control of Speech
- Nerves
Peripheral NM Control of Speech
- Nuclei
- Trigeminal and facial nuclei, the nuclei ambiguous & hypoglossal nuclei.
- These nuclei innervate the jaw, lips, palate, larynx, and tongue.
Co-ordinating Mechanisms of Speech
Controlling hemisphere:
- In 93% of the population who are right-handed, the speech function is subserved by the left cerebral hemisphere (the dominant hemisphere).
- In > half of the remaining 7% who are left-handed, the left hemisphere remains dominant and controls speech function. In the rest of people, speech is controlled by the right hemisphere.
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Disorders of speech
- Aphasia (Dysphasia)
- Dysarthria
- Aphonia
Def of Aphasia (Dysphasia)
It is an impairment of formulation of speech.
Types of Aphasia (Dysphasia)
Def of Motor/expressive/verbal/Broca’s aphasia
- Inability to formulate a meaningful speech.
- Patient understands the spoken words & will obey commands.
Lesion in Motor/expressive/verbal/Broca’s aphasia
- Broca’s area (in the posterior part of the inferior frontal gyrus and the lower part of the precentral gyrus)
Def of Nominal or amnestic aphasia
- Inability to name objects or subjects properly although the patient knows their nature and value.
Lesion in Nominal or amnestic aphasia
- angular gyrus or the superior temporal gyrus of the dominant hemisphere
Def of Sensory or receptive aphasia
- Inability to understand spoken or written words.’
- The patient’s speech is fluent, but words are used inappropriately leading to neologism
Lesion in Sensory or receptive aphasia
- the posterior part of the superior temporal gyrus, and part of the adjacent parietal lobe of the dominant cerebral hemisphere.
Def of Jargon/central/syntactical aphasia
- form of severe receptive aphasia with failure to produce correct words leading to neologisms and paragrammatism
Lesion in Jargon/central/syntactical aphasia
left temporoparietal region.
Def of Word Deafness
- Inability to understand spoken words but Speech production, reading and writing are normal
Lesion in Word Deafness
- posterior part of the superior temporal gyrus of the dominant hemisphere.
Def of Word Blindness
- Inability to recognize written words or letters,
Def of Alexia with agraphia (Visual Asymbolia)
- Inability to read or write
Lesion in Word Blindness
- the angular or supramargina! gyri of dominant parietal lobe
Lesion in Alexia with agraphia (Visual Asymbolia)
- left angular gyrus
Def of Agraphia
- Inability to write.
- It is a form of expressive aphasia
Lesion in Agraphia
- Near Broca’s area or association pathways in the posterior part of the middle frontal gyrus.
Def of acalculia
Inability to calculate.
Lesion in acalculia
left angular gyrus
Def of Amusia
Inability to appreciate musical sounds.
Lesion in Amusia
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Def of Global Aphasia
Impairment of both the expression and comprehension of speech.
Lesion in Global Aphasia
In the dominant hemisphere involving both Broca’s and Wernicke’s areas.
Def of Dysarthria
- It is an impairment of articulation due to a disorder of the neuromuscular mechanisms responsible for it
Causes of Dysarthria
Causes of Dysarthria
- Bilateral UMNL (supranuclear) lesion of cranial nerves 9, 10, or 12 (pseudobulbar palsy)
- Due to; congenital diplegia, double stroke, M. S., motor neuron disease or upper brainstem lesions.
- Results in: Spastic dysarthria results with slurred speech.
Causes of Dysarthria
- Bilateral LMNL of CN 9, 10, 12 (True Bulbar Palsy)
Due to diphtheritic polyneuritis or bulbar poliomyelitis.
Causes of Dysarthria
- Extrapyramidal Lesion
- Due to: Parkinsonism.
- Results in: rigid dysarthria leading to slow, quiet and monotonous speech.
Causes of Dysarthria
- Cerevellar Lesions
- Due to; MS, hereditary ataxias, cerebellar and cerebellopontine angle tumors, or anticonvulsant toxicity.
- Results in: ataxic dysarthria (slurred, explosive staccato or scanning speech).
Causes of Dysarthria
- Disorders of Ms
- Myasthenia gravis: produces a slurred speech with nasal tone and hoarseness which T with fatigue.
- Myotonia: leads to a “strangled” speech due to stiffness of the tongue.
- Facioscapulohumeral muscular dystrophy: leads to inability to pronounce labials.
Causes of Dysarthria
- Oral Lesions
such as false teeth, cleft palate, and tongue-tie.
Def of Aphonia
Loss of the ability to phonate but the patient can talk in a whisper.
Causes of Aphonia
- Laryngitis.
- Tumor or paralysis of the vocal cords.
- Hysterical: as a trial to escape from a stressful situation, the patient’s ability to phonate when coughing is a clue to the diagnosis of hysterical aphonia.
