Cognitive Neurology

Aphasia syndrome localizer

Teach aphasia through bedside dissociations: fluency, comprehension, repetition, naming, reading, and writing. The goal is to localize the language-network bottleneck before jumping straight to stroke labels or rehab slogans.

Dominant grammar: Nonfluent expressive aphasia

Syndrome presets

Start from the bedside language split

These presets are organized around the classroom-level language dissociations students actually remember: nonfluent versus fluent, repetition spared versus broken, and comprehension relatively intact versus heavily impaired.

Language profile

Which channels are preserved and which ones break

Fluency18%
Comprehension82%
Repetition34%
Naming44%
Reading58%
Writing30%

Spontaneous sample

"...want... water... no... hospital... home."

This is the first bedside clue students usually hear before any formal testing starts.

Repetition split

Repetition versus the rest of the profile

Repetition

34%

Split

+32

Positive values mean repetition is worse than the rest of the language profile; negative values mean repetition is paradoxically spared.

Auditory load

How fragile spoken-language comprehension becomes

Higher load means spoken language rapidly outruns the patient’s ability to map sound onto meaning.

Phenotype

Broca aphasia

nonfluentauditory load 28%

Effortful, agrammatic output with relatively preserved comprehension and disproportionately impaired repetition.

Fluency

18%

Speech rate, phrase length, and grammatical ease.

Comprehension

82%

How well bedside spoken language remains grounded in meaning.

Naming

44%

Object naming is often the clinical bridge between language knowledge and output bottlenecks.

Reading/Writing

44%

Written language often mirrors the same network bottleneck but can still expose extra dissociations.

Dominant hemisphere map

Which language node is most implicated

BrocaWernickearcuate bridgeant.post.dominant hemisphere language network

Dominant inferior frontal gyrus and adjacent anterior perisylvian language network.

Network logic

Why this bedside split happens

Language formulation and articulatory sequencing are bottlenecked, so the patient knows much more than they can efficiently convert into fluent propositional speech.

Speech is sparse, effortful, and grammatically reduced, but comprehension is much better than the output pattern initially suggests.

Weaker alternative

What not to confuse this with

Dysarthria alone is weaker because the problem is not just articulation: grammar, phrase length, and spontaneous verbal generation are all reduced.

Repetition

34%

One of the fastest high-yield pivots in bedside aphasia classification.

Naming

44%

Naming often fails across syndromes, but the reason it fails differs by network bottleneck.

Bedside probes

The task-level dissociations that settle the syndrome

Repetition probe

Fails on "No ifs, ands, or buts" with effortful fragments and omissions.

Repetition is the fastest bedside clue for separating core perisylvian aphasias from transcortical patterns.

Comprehension probe

Follows one- and two-step commands reasonably well, especially when syntax stays simple.

Command following tells you whether meaning is preserved, not just whether the patient can stay engaged.

Naming probe

Frequent word-finding pauses with preserved recognition of the target object.

Naming failure alone is nonspecific, but how it fails gives you the localization edge.

Reading and writing

Reading comprehension can exceed written output; writing often mirrors the agrammatism seen in speech.

Written language can echo or sharpen the same syndrome seen in speech.

Conversational sample

Short phrases, telegraphic grammar, and obvious effort.

Primary problem is language output formulation rather than a pure motor speech issue.

Auditory commands

Simple comprehension is much better than spontaneous expression.

Supports dominant frontal language-network injury over global aphasia.

Sentence repetition

Repetition collapses once phrase length and syntax increase.

Helps separate Broca and conduction patterns from transcortical motor aphasia.

Supportive communication

Rehab and teaching stance

  • Slow the exchange and accept multimodal output such as gesture, writing, or key words.
  • Use yes/no checks carefully, because comprehension is better than spontaneous verbal output.
  • Keep commands syntactically simple while preserving adult-level content.
Nonfluent does not mean unintelligent or globally confused. In Broca aphasia, the bottleneck is expressive language assembly.

Continue the loop

Pair language with stroke, neglect, anatomy, and tutoring

Brain Atlas

Post-clinical anatomical convergence

Stroke Vascular Territories

Acute neurovascular localization

Neglect Localizer

Consult-level spatial-attention localization

Neuro Tutor

Cross-module consult reasoning with explicit scoring