COGNITIVE TESTING AND LOCALIZATION MADE RIDICULOUSLY SIMPLE

1. Cognitive testing involved examination of the various cognitive domains• Cognitive domains as examined on the Mini-Mental Status Examination (MMSE) and the Montreal Cognitive Assessment (MoCA)

Cognitive Domain MMSE MoCA

Orientation Yes Yes

Memory - Learning/Delayed recall Yes Yes

Attention Yes Yes

Language Yes Yes

Visuospatial Yes Yes

Executive Function Yes Yes

• Neuropsychological testing involves detailed assessments of each cognitive domain

Cognitive Domain Examples of Specific Neuropsychological Tests

Orientation

Memory - Learning/Delayed recall Logical (story) memory, California adult verbal learning test (CVLT), Free-cued recall

Attention Reverse digit span, letter cancellation

Language Boston Naming Test, Token Test (comprehension)

Visuospatial Rey-O complex figure, block design

Executive Function Wisconsin card sorting, Stroop, Trails Making Test

Cognitive Testing & Localization 1

Assistant Professor (Neurology & Geriatric Medicine), University of Toronto

7th Canadian Conference on Dementia, Vancouver BC, October 4, 2013

David F. Tang-Wai MDCM FRCPC

Co-Director, University Health Network Memory Clinic

2. Each cognitive domain can be localized to a specific lobe in the brainExecutive Function Memory Language Visuospatial Arithmetic Praxis Facial

Recognition

Lobe in brain

Figure

Sample tests that can examine domain

Frontal Temporal Left Hemisphere Biparietal & occipial lobes

Left Parietal Left parietal Right temporal

• Modified Trails B• Digit span• WORLD/serial 7s• Verbal fluency• Letter cancelation

• Orientation• Learning &

delayed recall

• Reading• Writing• Naming• Comprehension• Repetition• Semantic

fluency

• Cube copy• Pentagons

copy

• Calculations (simple arithmetic)

• Ask patient to show how to...

• Identify famous faces

3. Localization can be further refined to a specific area within a lobe of the brainMemory Reading, wRiting,

aRithmeticFacial recognition Ideomotor praxis

Lobe

Where in lobe

Disorders to consider if first presenting symptom

Temporal Left parietal Right temporal Left parietal lobe

Hippocampus & Papez circuit

Angular & supramarginal gyrus

Inferior fusiform & lingual gyrus Inferior parietal lobule

Alzheimer’s dementia Alzheimer’s dementia (posterior cortical atrophy)

Frontotemporal dementia - right temporal variant

Corticobasal syndrome

Cognitive Testing & Localization 2

Memory Reading, wRiting, aRithmetic

Facial recognition Ideomotor praxis

Figure

Language Localization (left hemisphere)

Repetition Comprehension Fluency Naming Writing

Lobe

Figure

Left perisylvian area Left parietal/temporal Spontaneous speech - Left frontal lobe

Letter fluency (green)Semantic fluency (red)

Left temporal Left parietal (see previous)

Cognitive Testing & Localization 3

Frontal lobe syndromes

Dorsolateral Orbitofrontal Anterior Cingulate

Function

Figure

• Poor organizational strategies, problem solving, planning, shifting and maintaining sets, verbal working memory, and reduced verbal fluency

• Personality change: tactlessness, obsessive compulsive disorder; decreased empathy, socially inappropriate behavior; impulsive behavior; inappropriate jocular affect; emotional lability; poor judgment & insight; distractibility; increased sweets

• Apathy, little display of emotions, decreased motivated behavior/creative thought, failure of response initiation/suppression, poor response inhibition; lack of concern of personal hygiene, appearing unkempt

4. Guidelines to interpret cognitive testing - determining patterns1.1. Look at the affected cognitive domains in addition to the total score - this will help determine the pattern of impairment and localization

within the brain

1.2. Recall where the cognitive domains are localized within the brain

Executive function Memory Language Visuospatial

Localization Frontal lobe Temporal lobe (hippocampus/Papez circuit)

Left hemiphere Mainly right temporoparietal lobes

1.3. Common patterns seen on cognitive testing and representative dementing disorders

Cognitive Testing & Localization 4

Problems Seen on Testing Pattern Suggestive Of Examples of Disorders

OrientationDelayed word recall

Amnestic • Amnestic mild cognitive impairment• Alzheimer’s dementia

Attention3-step commandLearning (many trials)Trials B (MoCA)Letter fluency

Executive dysfunctionFrontosubcortical

• Vascular cognitive impairment• Parkinson’s disease• Dementia with Lewy bodies

Intersecting pentagonsNecker cube

Visuospatial • Posterior cortical atrophy• Alzheimer’s dementia• Dementia with Lewy bodies

NamingSemantic fluencyWritingComprehension

Aphasia • Primary progressive aphasia• Semantic dementia

Normal cognitive testing but change in behaviour Disinhibition or apathy behaviour • Behavioural variant frontotemporal dementia

1.4. In addition to the clinical history and the pattern of cognitive testing, a diagnosis can be made

Sample Cases Cognitive Testing Result Diagnosis

Case 1: 58 year-old man with 2 year history of progressive memory loss and impairment with his instrumental activities of daily living

MMSE = 22/30Orientation 7/10; Learning 3/3 in 1 trial; Attention 5/5; Recall 0/3; Language 8/8; Pentagon copy 1/1

Alzheimer’s dementiaCognitive testing revealed a primary amnestic pattern. Given the history of anterograde memory impairment with functional impairment, the clinical scenario is one of Alzheimer’s dementia.

Case 2: 88 year-old woman with 5 year history of progressive memory impairment, getting lost, unable to cook and balance the finances. No cerebrovascular risk factors or history of stroke.

MMSE = 18/30Orientation 7/10; Learning 3/3 in 2 trials; Attention 2/5 (WORLD); Recall 0/3; Language 6/8; Pentagon copy 0/1

Alzheimer’s dementia - severeCognitive testing revealed deficits in multiple domains. Given the history of anterograde memory impairment and other cognitive impairments associated with functional impairment, the clinical scenario is one of a moderate-to-severe Alzheimer’s dementia.

Cognitive Testing & Localization 5

Sample Cases Cognitive Testing Result Diagnosis

Case 3: 56 year-old with 5 year history of progressive apathy, emotional blunting, mental rigidity and dismissed from his job for “slacking off”

MMSE = 30/30 Frontotemporal dementia - behavioural variantCognitive screening was normal. The clinical history is primarily a change in personality and behaviour and is associated with an impairment with his iADLs (work). In FTD, especially the behavioural and executive dysfunction presentations, the cognitive testing can be normal or mildly impaired early in the disease.

Case 4: 74 year-old woman presenting with visual hallucinations, slowness in thought, shuffling gait, and “memory” problems of 1 year in duration

MMSE = 25/30Orientation 10/10; Learning 3/3 in 5 trials; Attention 3/5 (WORLD); Recall 3/3; Language 8/8; Pentagon copy 0/1

Dementia with Lewy BodiesCognitive testing revealed intact memory but difficulties with attention/executive function (WORLD), frontosubcortical slowing (excess number of trials to learn 3 words), and visuospatial dysfunction. With the history of parkinsonism, visual hallucinations and some cognitive impairment, the clinical scenario is consistent with DLB.

Case 5: 78 year-old math teacher with known Alzheimer’s disease presents with acute confusion.

Previous MMSE 26/30 days prior to ictusOrientation 9/10; Learning 3/3 in 1 trials; Attention 5/5 (serial 7’s); Recall 0/3; Language 8/8; Pentagon copy 1/1

MMSE on admission = 20/30Orientation 9/10; Learning 3/3 in 1 trials; Attention 0/5 (serial 7’s); Recall 0/3; Language 8/8; Pentagon copy 0/1

Acute left parietal strokeRepeat cognitive testing revealed sudden decline with visuospatial and serial 7s (a crude measure of calculations). These functions localize to the left parietal lobe. Given the sudden change, this man had a stroke in the same area.

Cognitive Testing & Localization 6

Cognitive Testing & Localization 7