Modes of Aphasia

Perisylvian Aphasias (Repetition Impaired)

1. Broca Aphasia (Non-fluent / Expressive)

• Lesion: Posterior inferior frontal gyrus (Brodmann areas 44 & 45) + adjacent cortex and subcortical white matter; territory of upper division of left MCA
• Speech: Non-fluent, hesitant, telegraphic ("agrammatism") - e.g., "wife come hospital." Phonetic errors inconsistent utterance-to-utterance (literal paraphasias)
• Comprehension: Relatively preserved, though complex syntax is impaired
• Repetition: Impaired
• Naming: Impaired (often "tip of the tongue" phenomenon)
• Reading/Writing: Both impaired
• Associated signs: Right hemiparesis, right hemisensory loss, apraxia of left limbs
• Behavior: Patients are typically aware of deficits; depression is common

2. Wernicke Aphasia (Fluent / Receptive)

• Lesion: Posterior superior temporal gyrus (Wernicke area, Brodmann area 22); territory of lower division of left MCA
• Speech: Fluent, effortless, sometimes logorrhea (excessive) - but empty of meaning; filled with verbal paraphasias, neologisms, and jargon
• Comprehension: Impaired - even for simple commands
• Repetition: Impaired
• Naming: Severely impaired with bizarre paraphasic substitutions
• Reading: Impaired (similar to auditory comprehension)
• Associated signs: Often no hemiparesis; right hemianopia or superior quadrantanopia may be present
• Behavior: Patients are often unaware of their deficits (anosognosia); may become agitated or paranoid when not understood

3. Global Aphasia

• Lesion: Large left hemisphere lesion involving both inferior frontal AND superior temporal regions + much of parietal lobe; most of left MCA territory
• The most severe form - essentially Broca + Wernicke combined
• Speech: Mute or non-fluent
• Comprehension: Impaired
• Repetition: Impaired
• Naming: Impaired
• Reading/Writing: Impaired
• Associated signs: Dense right hemiplegia, hemisensory loss, hemianopia
• Prognosis: Recovery may continue through the second 6 months post-stroke; patients often evolve toward Broca aphasia if the superior temporal gyrus is spared

4. Conduction Aphasia

• Lesion: Arcuate fasciculus (disconnects Broca from Wernicke areas); involves the supramarginal gyrus and/or the insula
• The hallmark: Disproportionately impaired repetition - a patient who can hold a conversation cannot repeat even single words. Classic example: patient could not repeat "boy" but said "I like girls better."
• Speech: Relatively fluent, but with literal paraphasic errors and frequent self-correction attempts (conduite d'approche)
• Comprehension: Preserved
• Repetition: Severely impaired (out of proportion to spontaneous speech)
• Naming: Moderately impaired
• Associated signs: Right hemisensory loss, mild hemiparesis; limb apraxia

Transcortical Aphasias (Repetition Preserved / Spared)

5. Transcortical Motor Aphasia

• Lesion: Anterior or superior to Broca area (supplementary motor area / anterior watershed zone)
• Speech: Non-fluent, reduced, but can become fluent when prompted or completing a phrase
• Comprehension: Intact
• Repetition: Preserved (often echolalia)
• Naming: Impaired

6. Transcortical Sensory Aphasia

• Lesion: Posterior watershed zone, posterior to Wernicke area (temporo-parieto-occipital junction)
• Speech: Fluent with paraphasias - similar to Wernicke, but repetition is intact
• Comprehension: Impaired
• Repetition: Preserved
• Naming: Impaired

7. Mixed Transcortical Aphasia (Isolation Aphasia)

• All modalities impaired except repetition
• Patient can only repeat (echo) what is said
• Lesion: Watershed zone infarcts isolating the perisylvian language zone

Non-Perisylvian Aphasias

8. Anomic Aphasia

• Lesion: Variable - can be the angular gyrus, temporal-parietal junction, or any part of the language network; also seen in recovery from other aphasias
• The mildest and most common aphasia type
• Speech: Fluent, but marked word-finding difficulty (anomia). Patients circumlocute ("the thing you use to... cut bread")
• Comprehension: Intact
• Repetition: Intact
• Naming: Impaired (defining feature)
• Often a residual of other aphasias after recovery

Quick Reference Summary Table

Anatomy at a Glance

• Broca area: Posterior inferior frontal gyrus (BA 44, 45) - production
• Wernicke area: Posterior superior temporal gyrus (BA 22) - comprehension
• Arcuate fasciculus: White matter tract connecting the two - when cut, causes conduction aphasia
• Angular gyrus: Parietal lobe - reading, writing, and naming
• Watershed zones: Medial/superior frontoparietal and posterior parieto-occipital - transcortical aphasias

MRI: Broca Aphasia Infarct

Special Notes

• Aphemia: A rare transient muteness from isolated left frontal/Broca area lesions; classified separately if writing is normal (may not be a true language disorder)
• Primary Progressive Aphasia (PPA): Unlike the above acquired aphasias (typically from stroke), PPA is a neurodegenerative syndrome that worsens over time
• Pure Word Deafness: Severe auditory comprehension deficit with preserved reading/writing; lesion isolates Wernicke area from auditory input
• All aphasias impair naming to some degree; naming is the most sensitive indicator of dominant hemisphere language dysfunction

• Columns: Aphasia Type, Lesion/Zone, Fluency, Comprehension, Repetition, Naming, Reading, Writing, Associated Signs, Key Feature/Mnemonic
• Color-coded badges: green (intact), red (impaired), orange (variable)
• Alternating row shading for easy reading
• Abbreviation legend at the bottom

• Left: Anatomy of language areas + vascular territories
• Center: Bedside examination steps + paraphasia types
• Right: Diagnostic algorithm (fluency/comprehension/repetition matrix), hemiparesis clues, awareness patterns, recovery timelines, and PPA variants