Aphasia Types and Brain Areas: Stroke, Language Impairments, and Speech Disorders

Aphasia

Language impairment resulting from (usually) damage in left hemisphere

Affecting form and content of reception and expression (including gesture)

Pragmatics intact (if RH spared)

Usually due to ischaemic stroke.

Middle Cerebral Artery (MCA)

Particularly at risk for stroke

Nonfluent Aphasia

characterized by effortful, halting speech and motor programming disorder.

Motor symptoms of nonfluent aphasia

Contralateral lower facial droop and tongue weakness (right sided)

Types of nonfluent aphasia

Broca's, Transcortical Motor, Global

Fluent Aphasia

characterized by fluent speech but poor word retrieval and comprehension.

Fluent aphasia motor symptoms

No motor impairment but possible visual field deficits

types of fluent aphasia

Wernicke's, Transcortical Sensory, Conduction, Anomic

Broca's Aphasia

Nonfluent, agrammatic speech associated with Brodmann area 44 and 45, characterized by effortful speech and good auditory and reading comprehension.

Transcortical Motor Aphasia

Nonfluent aphasia associated with Brodmann areas 8 and 9, characterized by difficulty with initiation of speech and good repetition.

Global Aphasia

Most common type of nonfluent aphasia resulting from large, widespread damage to perisylvian language zone, characterized by severely limited verbal output.

Wernicke's Aphasia

Fluent speech associated with Brodmann area 22, characterized by semantic and phonemic paraphasias, poor word retrieval, and poor comprehension.

Transcortical Sensory Aphasia

Fluent aphasia associated with Brodmann areas 7, Wernicke's area intact but becomes isolated, characterized by poor comprehension, poor word retrieval and good repetition.

Intact with Right Hemisphere damage (cognitive communication disorder)

“Language without communication” as linguistic functions intact

Affected with right hemisphere damage (cognitive communication disorder)

• Visuospatial deficits (LH neglect in RH damage)

• Affect and prosody (both flat) – receptive and expressive

• Higher cognitive functions – attention, inferencing, pragmatics

Contralateral hemiparesis

Weakness on the opposite side of the body, often associated with nonfluent aphasia types.

Contralateral lower facial droop

Drooping of the lower face on the opposite side of the body, often seen in Broca's aphasia.

Motor programming disorder (AOS)

A disorder affecting the ability to plan and coordinate the movements necessary for speech- seen in Broca’s aphasia

Neologisms

Newly coined words or expressions, often seen in Wernicke's aphasia.

Phonemic paraphasias

Unintended substitutions of sounds in words, commonly observed in fluent aphasia.

Semantic paraphasias

Unintended substitutions of words with similar meanings, often seen in fluent aphasia.

Agrammatic speech

Speech that lacks grammatical structure, often seen in nonfluent aphasia.

Good auditory and reading comprehension

Ability to understand spoken and written language, typically preserved in Broca's aphasia.

Poor self-monitoring

Inability to recognize and correct one's own speech errors, often seen in Wernicke's aphasia.

Visual field deficits

Loss of vision in part of the visual field, which may accompany fluent aphasia types.

Conduction Aphasia

Fluent aphasia, Damage to arcuate fasciculus connecting Broca's and Wernicke's areas, Phonological paraphrasias, aware of errors

Anomic Aphasia

A 'mild' form of aphasia characterized by word finding difficulties.

Affected areas in Anomic Aphasia

Usually smaller areas in the frontal lobe, angular gyrus, or inferior temporal gyrus.

Cognitive Communication Disorder

Impairments due to disruption to cognitive abilities.

Right Hemisphere Damage

Linked to cognitive communication disorder

Usually due to stroke, can also be due to tumors or diseases

Visuospatial deficits

LH neglect in RH damage.

ABI (traumatic brain injury)

Involves focal and diffuse damage.

Progression of primary progressive aphasia

Decline of language abilities followed by a decline in cognition

Primary progressive aphasia

Subtype of frontotemporal dementia

Apraxia of Speech

Caused by damage usually to LH frontal lobe, impairing planning/programming of speech movements.

Difficulties with Apraxia

• Initiating speech

• Producing longer words

• Distorted articulation

• Abnormal prosody

• Automatic speech/phrases can be easier

Islands of fluency

May work very hard to produce target word and then suddenly produce a perfectly articulate sentence

Dysarthria

Impairment in the ability to execute muscle movements for speech

Differences between Apraxia and Dysarthria

Dysarthria is primarily a muscle issue, while apraxia of speech is a motor planning problem.

Types of dysarthria

flaccid, spastic, ataxic, hypokinetic, hyperkinetic and mixed

Speech processes affected by dysarthria

• Affects all speech processes: respiration, phonation, resonance, articulation and prosody