| 3 Dimensions: | | |
| Dimension #1: Laterality | Left | Right |
| Cognitive | Cognitive |
| Language: dysphasia, dyslexia, dysgraphia | Visuospatial deficits |
| Other dysfunction of higher cortical functions: apraxia, agnosia | Nonverbal memory deficit |
| Verbal memory deficit | Nonverbal fluency |
| Verbal fluency impairment | Left hemi-neglect |
| Dyscalculia | Behavioral: Dressing apraxia, anosognosia, prosopagnosia |
| Finger agnosia | |
| Motor: Contralateral hemiparesis and upper neuron signs | Motor: Contralateral hemiparesis and upper motor neuron signs |
| Sensory: Contralateral hemisensory loss, including dysgraphesthesia, astereognosis, and extinction with double simultaneous stimulation | Sensory: Contralateral hemisensory loss, including dysgraphesthesia, astereognosis, and extinction with double simultaneous stimulation |
| Dimension #2: Anteriority | Anterior | Posterior |
| Cognitive | Cognitive |
| Language: Nonfluent aphasia. | Language: Fluent aphasia |
| Emotional: Expressive dysprosodia | Emotional: Receptive dysprosodia |
| Executive cognitive dysfunction: impaired sequencing, planning, working memory; go/no-go deficit; diminished verbal fluency (word-generation) | Visuospatial deficits |
| Behavioral | Spatial disorientation |
| Stimulus-bound behavior/environmental dependency | Hemi-neglect |
| Motivation: apathy, loss of initiative, abulia | Diminished nonverbal fluency (design-generation) |
| Personality change: disinhibition, loss of social graces, loss of empathy and social judgment | Behavioral: Anosognosia, prosopagnosia, dressing apraxia |
| Motor: Luria motor-sequencing deficit; gait apraxia; primitive (“frontal release”) signs | |
| In general: sparing of personality and motivation, although right parietal disease may be associated with personality change, apathy, and emotional indifference. |
| Motor: Contralateral hemiparesis (less severe than anterior) |
| Sensory: Contralateral hemisensory loss, as above |
| Dimension #3: Verticality | Cortical | Subcortical (Basal ganglia) |
| “Frontal” (i.e., anterior) behaviors and cognitive deficits | “Frontal” (i.e., anterior) behaviors and cognitive deficits |
| Cognitive: Aphasia, agnosia, apraxia | Cognitive: |
| Executive cognitive impairment | Executive cognitive impairment |
| Retrieval memory deficit | Retrieval memory deficit |
| Recall memory deficit (amnesia) | |
| Emotional: dysprosodia | |
| Behavioral: Depression, apathy, prosopagnosia, anosognosia, dressing apraxia | Behavioral: Depression, apathy, flat affect |
| Motor: Contralateral hemiparesis | Motor: Slow speech and gait, dysarthria |
| Extrapyramidal Motor Signs: rigidity, cogwheeling, dyskinesia |
| Sensory: Contralateral cortical sensory loss, as above | |
| What is the frontal–subcortical paradox? | It refers to the paradox of so-called “frontal lobe” features resulting from subcortical dysfunction. Specifically, it refers to the presence of “anterior” symptoms (above) resulting from disruption of subcortical components of the frontal cortical–basal ganglia–thalamic circuits | |
| 2 DBQs: | DBQ #1: Lateral to Posterior? What features are expected in DAT (or other posterior dysfunction disorders) | Or, ask: Having reviewed laterality brain–behavior relationships, what features are expected with posterior hemispheric dysfunction? |
| DBQ #2: Cortical to subcortical? How do we explain the occurrence of “frontal,” (i.e., anterior hemispheric) features in basal ganglia disease? | |
| Clinical examples: | Laterality: | |
| 4 Model disorders for 3 dimensions: | Case #1: Tumor, stroke, or head injury with lateralized impairments |
| Anteriority: |
| Case #2: Anterior Hemispheric Dysfunction (e.g., FTD) |
| Case #3: Posterior hemispheric dysfunction (e.g., DAT) |
| Vertical (Cortical–Subcortical): |
| Case #4: Basal ganglia disease (including features of “frontal” dysfunction (i.e., illustrating the frontal-subcortical paradox; e.g., progressive supranuclear palsy) |
| Applications and refinements: | 3D approach provides opportunity to introduce and review other key neurobehavioral concepts, including: | |
| °Classification of aphasia, aprosodia, apraxia and agnosia |
| Other syndromes amenable to 3D approach: | °Hemispheric specialization: (Verbal/Nonverbal |
| °Aphasia | Sequential/Holistic) |
| °Aprosodia | °Cortical networks and localization of function. |
| °Disorders of attention | |