Types of Aphasia

• Established in the 1960s by the Boston School (Geschwind et al.) in reference to the work of Lichtheim (1885)
• Based on the syndromes observed in vascular pathologies

2 major types of aphasias

1. Perisylvian
2. Transcortical

Signs

1. Reduced oral expression: word finding difficulty, agrammatism (little conjugation), articulatory disturbances (articulatory movement programming difficulties), verbal paraphrasias ("bottle" for "mushroom") and phonemic ("bouleille" for "bottle"), informative content, repetition and reading aloud are disturbed; phenomenon of Voluntary-Automatic Dissociation, automatic responses, singing and familiar melodies preserved.
2. Preserved oral comprehension but with length and syntactic complexity effects.
3. Spontaneous and dictated written expression impaired.
4. Impaired written comprehension.
5. Awareness of the impairment.

Associated Disorders

• Right hemiplegia
• Bucco-facial apraxia
• Ideomotor apraxia

Lesions

• Left anterior lesions
• Subcortical extension
• Extension to parietal lobe

Signs

1. Fluent oral expression (normal rate, even logorrhea) without articulatory disturbances: phonemic and verbal paraphrasias, neologisms and jargon (semantic or phonological type paraphrasias), addition of words or phrases to the target item, dyssyntax, little informative speech, altered repetition, altered reading aloud.
2. Deficient oral comprehension and verbal deafness (do hear but do not interpret verbal data).
3. Spontaneous and dictated written expression impaired but preserved graphism.
4. Deficient written comprehension (dissociation between oral and written modalities in case of SV).
5. Multiple clinical forms (SV or written language disorder).
6. Anosognosia.

Associated Disorders

• Right homonymous hemianopsia (RVHD)
• Sensitivity disorder on the right (hemiparesis)
• Praxis disorders

Lesions

= left temporo-parietal lesions

• Anterior lesions: SV (more difficulty in understanding isolated words rather than in context). Written language may be less impaired.
• Posterior lesions: comprehension difficulties (more difficult for sentences than for isolated words).

Signs

1. Fluent oral expression, +- logopenic (pausing to search for words): word finding difficulty, phonemic paraphrasias and approaches (struggling to get to the correct pronunciation), severely impaired repetition, altered reading aloud, no articulatory disturbance, correct syntax.
2. CO and CE preserved but length effect.
3. Impaired written expression: literal paragraphias and graphemic approaches, significant difficulties in writing pseudowords under dictation.
4. Phonological short-term memory disorders.
5. Awareness of the impairment.

Associated Disorders

Very variable: sometimes RVHD (or quadranopsia), sometimes sensory disorders, sometimes ideomotor apraxia.

Lesions

• Lower left parietal regions
• Subcortical white matter
• Interruption of the arcuate fasciculus connecting T1 to F3

Signs

1. All language modalities are severely impaired and associated disorders are severe.
2. Massive reduction of oral expression: mutism + stereotypies.
3. Oral comprehension severely altered but understanding of "non-verbal language" Benson.
4. Massive reduction of written expression.
5. Written comprehension severely altered.

Associated Disorders

• Right hemiplegia
• RVHD
• Bucco-facial apraxia
• Sensory disorders...

Lesions

• Extensive perisylvian lesions (left FTP)
• Subcortical white matter

Clinical pictures intermediate between global aphasias and Broca type aphasias (Goodglass et al., 2001)

Signs

1. Very reduced oral expression: severe anomia + altered repetition.
2. Significant impairment of comprehension (<50%)
3. Very impaired LE

Signs

1. Fluent oral expression or logopenic
2. Isolated word finding difficulty with orwithout loss of meaning
3. Paraphrases

Etiology

• Either "pure" anomia
• Or the result of an aphasia (lack of access to phonological lexicon output)
• Or a sign of non-aphasic disorders (AD, semantic dementia...)

Lesions

• Left inferior temporals
• Other locations if a consequence of aphasia

Signs

1. Deficiency in verbal initiation and spontaneous incitation: initial period of mutism (akinesthetic mutism), then a quantitative reduction in discourse, word finding difficulty (phonological and contextual cues +), no articulatory disturbances, repeating words of the interlocutor, reduction of syntactic elaboration, perseverations, preserved repetition and reading aloud, correct automatism if prompted.
2. CO + CE normal
3. Impaired written expression (reduction, literal paragraphias, dysyntax)

Associated Disorders

• Variable motor deficit
• Poor spontaneous and emotional gesturing (general behavioral adynamia)

Lesions

• Left prefrontal (internal, AMS, or dorsolateral) or capsulo-striatal
• Affecting fibers connecting AMS to Broca's area, while sparing Broca's area itself

Signs

1. Fluent oral expression: characteristics of Wernicke's type aphasia (verbal, semantic, more rarely phonemic paraphrasias, dyssyntax), preserved repetition (echolalias).
2. Altered oral and written comprehension.
3. Impaired written expression.

Associated Disorders

• RVHD
• Sensitivity disorders
• Visual agnosia

Lesions

• Left OTP intersection (behind W's area)
• Underlying white matter (isolation of semantic representations)

Signs

1. Isolation syndrome of the language areas
2. Characteristics of TCM and TCS
3. Very reduced oral expression: stereotypies, few automatic productions, echolalic responses, very altered reading aloud. Resembles global aphasia and mixed non-fluent aphasia but relatively preserved repetition (+ correction of grammatical errors in repetition).
4. Very impaired oral and written comprehension
5. Very impaired written expression

Lesions

• Multifocal brain lesions with diffuse lesions of anterior and posterior associative cortices sparing the perisylvian region
• Extensive lesions of the crown bordering the language areas in the left hemisphere

• Motor Aphasias vs. Sensory Aphasias
• Anterior Aphasias vs. Posterior Aphasias
• Expressive Aphasias vs. Receptive Aphasias
• Non-Fluent Aphasias vs. Fluent Aphasias