Neurocognitive Disorders & Aging

Introduction

• Lecture 10 focuses on Neurocognitive Disorders & Aging, on April 2, 2025.
• The lecture will discuss why you should care about these disorders.

Agenda

• A review of Neuropsychology and Cognition will be provided.
• Focus on the distinction between Diagnosis and Etiology.
• Discussion on Neurocognitive Disorders.
• Examines both Neurodegenerative and Acquired disorders.
• Neurodegenerative disorders include Alzheimer's, other dementias, and Parkinson's Disease.
• Acquired disorders include Traumatic Brain Injury.
• Exploration of "Rule outs," considering normal aging, lifestyle, psychiatric, and medical factors.
• Overview of Treatments, including Pharmacotherapy, Psychotherapy, Surgical Intervention, and Cognitive Rehabilitation.

Brain-Behaviour Mapping

• The frontal lobe is responsible for personality, emotions, arousal, intelligence, concentration, decision-making, planning, problem-solving, awareness, voluntary movement, speech, writing, and behaviour control.
• The parietal lobe is responsible for sensations (pain, touch, temperature), sensory information interpretation (size, colour, shape), spatial understanding, and math calculations.
• The temporal lobe is responsible for language, hearing, memory (long-term storage), organization, planning, behaviour, and emotions.
• The occipital lobe is responsible for vision and interpreting what you see.

Neuropsychological Assessment

• Involves assessing background and history, including sociodemographic variables, as well as medical and psychiatric history.
• Starts with current complaints or the presenting problem in cognitive, psychiatric, motor/system, and functional domains.
• Includes objective cognitive testing, neuroimaging, genetic, or other medical testing and behavioral observations.
• Collateral information from other sources is sometimes used.

Speed and Executive Abilities

• Simple processing speed is evaluated.
• Processing speed with executive components (switching & response inhibition) is assessed.
• It considers how performance changes when an executive component is added.

Memory

• Memory assessment includes demos of the California Verbal Learning Test and Story Learning.
• Story learning may be easier for individuals with executive functioning deficits due to its structured nature.

Stages of Memory

• Stages of memory include encoding, storage, and retrieval.
• Unstructured lists of words places high demand on encoding.
• Cues can parcel out executive components for a purer measure of retrieval.
• Structured tests place lower demands on executive abilities.

Neurodegenerative Disorders: General Characteristics

• Degeneration of neural matter occurs over time.
• Gradual decline in cognitive and intellectual abilities.
• Stepwise progression, or slowly progressive.
• Impairment in social and occupational functioning.
• More basic functioning declines over time.

Neurodegenerative Disorders: Subtypes

• Cortical subtypes include Alzheimer's Disease (AD), Fronto-Temporal Dementia (FTD), Primary Progressive Aphasia (PPA), and Semantic Dementia (SD).
• Cortical types usually cause memory, language, and functioning deficits.
• Subcortical subtypes include Parkinson's Disease (PD), Lewy Body Dementia (LBD), Huntington's Disease (HD), and Multiple Sclerosis (MS).
• Subcortical types usually cause movement disorders and more slowing physically.
• Dementia is a diagnosis (syndrome), while the subtypes are etiologies.

Diagnosis vs. Etiology

• Diagnosis is "What is happening?" and is based on observable symptoms and abilities.
• Dementia is an example of a diagnosis.
• Etiology is "Why is this happening?" and refers to the underlying cause.
• Alzheimer's Disease is an example of an etiology.

Dementia

• Major Neurocognitive Disorder in the DSM-5.
• Involves cognitive decline in one or more domains.
• Subjectively reported or observed and confirmed via objective cognitive testing.
• Causes impairment in functioning, including grooming, household tasks, social activities, managing appointments, finances, and transport.
• Dementia is a syndrome, not a disease.

Alzheimer's Disease

• Most common type of dementia (55-80% of cases).
• Typically begins after age 65.
• Slowly progressive.
• Early onset is associated with quicker progression/decline.
• Death typically occurs 8-10 years after diagnosis.
• Decline includes physical decline and independent diseases.

Alzheimer’s Disease: Neuropathology

• First described by Alois Alzheimer in 1906.
• Autopsy findings include Neurofibrillary Tangles and Amyloid Plaques.
• Neurofibrillary Tangles are tangles and twists in nerve cells in the brain
• Amyloid Plaques are deposits of protein accumulating in the spaces between cells of the cerebral cortex, hippocampus, and other memory-related areas.

Alzheimer's Disease: Neuropsychology

• Typical subjective reports include forgetfulness, memory loss, and attention deficits.
• Functional consequences involve repeating oneself, forgetting conversations, getting lost, and decline in ADLs.
• Cognitive testing shows deficits in memory, learning, language, and visuospatial skills.

Alzheimer's Disease: Neuropsychology: Cognitive Testing

• Memory (List learning – e.g., California Verbal Learning Test).
• Learning across trials 1-5 is relatively intact.
• Very impaired recall after a delay.
• Impaired recognition.
• Language (Naming - e.g., Boston Naming Test).
• Several circumlocutions.
• Semantic and phonemic paraphasias.
• Visual-spatial skills are impacted in later stages of the disease.

Fronto-Temporal Dementia (FTD)

• Mean age of onset is 45 – 60 (Range: 21–75).
• Median illness duration is 8 years (Range: 2 - 20 years).
• 50% of cases have a family history of neurodegenerative disease.

FTD: Neuropsychology

• Behavioural changes are present early.
• Loss of social awareness and insight.
• Personal neglect.
• Disinhibition, and impulsivity.
• Mental rigidity/inflexibility.
• Perseveration.
• Cognitive changes follow.
• Impaired executive functions.
• Language deficits.
• Memory deficits include poor retrieval.
• Preserved Visuospatial and Perception.

FTD: Subtypes

• Disinhibited: Restless, purposeless, unconcerned, behavioural symptoms are more prominent than cognitive symptoms
• Apathetic: Inertia, loss of volition, unconcerned, mental rigidity.
• Stereotypic: Pronounced behavioural stereotypies, compulsive, and ritualistic traits.

Primary Progressive Aphasia

• Mean age of onset is 50-65.
• Has equal sex incidence.
• Median illness duration is 8 years (Range: 4 – 12).
• "Broca's aphasia"
• Gliosis and atrophy in Neuropathology.
• Frontal-temporal atrophy in Neuroimaging.
• Impaired naming and verbal ability, non-fluent speech, impaired repetition, and phonemic paraphasias.

Semantic Dementia

• Mean age of onset is 50-65.
• More common in females than males.
• Median illness duration is 8 years (Range: 3 – 15).
• "Wernicke's aphasia"
• Gliosis and atrophy in Neuropathology.
• Posterior-temporal atrophy in Neuroimaging.
• Impaired word meaning and general knowledge, but preserved visuospatial functioning.

Parkinson's Disease (Dementia)

• Prevalence: 1% of population over age 60.
• Motor symptoms: Bradykinesia, muscle rigidity, tremor, postural instability, and slow/shuffling gait.
• Unilateral symptom onset is typical.
• Cognitive symptoms: Deficits in processing speed, attention, and executive abilities that worsen, new deficits in visuospatial skills and language
• Dopaminergic hypothesis and Hallucinations are likely.

Parkinson's Disease: Treatment

• Targets motor symptoms.
• Uses Dopaminergic medications (e.g., Levodopa to increase dopamine in basal ganglia).
• Utilizes Deep Brain Stimulation when medications are not greatly responsive.

Neuropsychological Assessment Demo: Visuo-spatial Perception

• Dorsal stream goes Occipital -> parietal, it's the "where/how" pathway.
• Assessed using the Judgement of Line Orientation test.
• Ventral stream goes Occipital -> temporal, it's the "what" pathway.
• Assessed using the Visual Object and Space Perception test.
• Alzheimer's and Parkinson's disease affect the dorsal stream first.

Dementia with Lewy Bodies

• Features of both cortical and subcortical dementias.
• Affects 1-2% of the population over age 65.
• Lewy bodies (alpha-synuclein proteins accumulate in the cortex and brainstem).
• Motor symptoms are similar to PD (‘Parkinsonism’).
• Cognitive deficits are similar to PD but can precede or co-occur with motor symptoms.
• Causes visual hallucinations.
• Disrupts sleep.

Multiple Sclerosis

• Immune system attacks white matter in the brain, can be seen on MRI.
• Prominent symptoms include vision problems, dysarthria, numbness, and fatigue.
• The disease progression occurs at different rates, causing scarring in different regions.

Acquired Neurocognitive Injuries

• Traumatic Brain Injury (TBI) is a traumatically induced alteration in brain function or other evidence of brain pathology.
• Classified as mild, moderate, or severe, based on what happened during the injury.
• Presents with post-concussive symptoms.
• With psychological and functional deficits.

Treatment

• Biological treatments for cognitive decline include Cholinesterase inhibitors (increase acetylcholine) and NMDA receptor antagonists (regulate glutamate).
• Cognitive Rehabilitation using Memory Strategies (External/Internal).
• Includes Lifestyle factors, Psychosocial support, and Environmental modifications.

Differentials

• Ruling out reversible factors is important.
• Reversible factors include Psychiatric, Medical, Sleep, Hormones, Substances, Medications, Diet, and Other factors.

Final Exam

• Date: Wednesday, April 9th.
• Time: 7:00 to 9:00 pm.
• Locations: Room AA112 (A - Jalali) & Room AC223 (Jannat-Z).
• 40% of your grade.
• Consists of 45 Multiple Choice Questions and 1 Short Answer Question (multi-part).
• Covers Lectures 8-10 and Chapters 11, 13, 16.
• You will need pencils, pens, and a Tcard.