Understanding Dementia and Neurocognitive Disorders

Dementia

• Acquired neurological syndrome involving persistent, progressive decline in intellectual function
• Major Neurocognitive disorder is the new term

Diagnostic Criteria

• Deficits must interfere with independence
• One or more of the following core mental functions must be deficient:
  • Learning and memory
  • Language
  • Executive functions
  • Complex attention
  • Perceptual motor skills
  • Social-cognitive
• Daily living tasks impacted include:
  • Continence
  • Dressing
  • Safely moving
  • Managing finances
  • Bathing
  • Driving

Mild Neurocognitive Disorder/ Impairment (MCI)

• It is considered a preclinical condition suggesting dementia risk
  • 10-15% of MCI patients develop dementia per year
• Transition between cognitive changes in healthy aging and Alzheimer's
• People can be asymptomatic, but PET scans may show plaque buildup

Diagnosing MCI

• Self-reported memory issues are confirmed by a family member
• Standardized testing reveals measurable memory impairment
• Daily living activities are not impeded because there is no impairment to thinking or reasoning

Dementia Subtypes

• Dementia is an umbrella term
• Subtypes correspond with brain pathologies
• Common dementias include vascular and Alzheimer's

Vascular Dementia

• Results from bilateral, repeated CVAs
• Multiple diffuse cortical and subcortical infarcts
• Display abrupt onset with stepwise deterioration and fluctuation
• Symptoms and communication deficits rely on infarction type, location, and frequency
• Produces focal neurological symptoms like motor deficits, dysarthria, dysphagia, hemiplegia, incontinence

Alzheimer’s Disease (DAT)

• Most common irreversible dementia, accounting for 60-80% of cases
• Survival averages 3-4 years in late stages
• Etiology is unknown, but genetic factors are strongly suggested
• Likely multifactorial with amyloid plaques as AD biomarkers

Risk Factors for DAT

• Old age
• Family history
• Down syndrome (100% risk at ~40 years old)
• Depression
• Hypertension
• Head trauma
• Little exercise

DAT Neuropathology

• Cerebral atrophy primarily in mid-frontal areas, parietal-temporal association areas, cerebral cortex, and hippocampus
• Ventricular dilation indicates loss of brain mass
• Neurofibrillary tangles and neuritic plaques form, involving:
  • Two altered proteins: tau (in NF tangles) and Amyloid (in plaques) that work together
  • Mutated tau protein destroying microtubules causing neurofibrillary tangles
  • Neuritic plaques destroying synaptic connections and disrupting neuronal messages
• Granulovacuolar degeneration occurs via nerve cell degeneration and small fluid-filled cavities
• Cholinergic hypothesis posits acetylcholine (a brain neurotransmitter for memory function) decreases in dementia
  • Cholinesterase, an enzyme, breaks down acetylcholine
  • Cholinesterase is also found in neuritic plaques and leads to amyloid deposits
• Free radicals, oxidative stress, and antioxidants

Calcium Hypothesis

• High brain calcium concentrations exist
• Glutamate, an excitatory neurotransmitter, helps with processing, storage, and retrieval
• Amyloid causes neuronal degeneration, releases excess glutamate, overexcites glutamate receptors causing excitotoxicity which precipitates postsynaptic calcium ion influx into nerve cells

Behavioral Disturbances

• Approximately 58% of those with DAT experience significant behavioral symptoms that worsen over time
• Symptoms include:
  • Delusions
  • Agitation
  • Diurnal rhythm disturbances
  • Motor restlessness
  • Violence
  • Emotional lability
  • Hallucinations

Stages of DAT

Early (Mild) - 1-3 years

• Subtle memory problems emerge, alongside impaired visuospatial skills
• Reasoning and judgement are affected, coupled with disorientation
• Depression, indifference, and mood changes manifests, as well as:
  • Mild language deficits
    • Naming problems
    • Verbal paraphasias and circumlocution
    • Comprehending abstract meaning
    • Impaired picture description
    • Problems with divergent naming

Mid (Moderate) - 5-7 years

• Severe memory problems
• Generalized intellectual deterioration
• Restlessness, agitation, and hyperactivity occur, as well as:
  • Profound disorientation (person, place, time)
  • Difficulty in dressing
  • Wandering
  • Lack of affect, tact, and judgement
  • Social indifference

Late (Severe) - 2-5 years

• Motor and communication problems
• Complete incontinence exists
• Weight loss occurs
• Difficulty initiating or having meaningful conversations are present
• Literally paraphasias, empty speech, and jargon are present
  • Hyperfluency / rapid rate of speech
  • Impaired auditory & reading comprehension
  • Impaired aloud reading
  • Echolalia, palilalia

Dementia Syndromes

• Degenerative disorders include Pick's and Lewy Body diseases
• Vascular disorders include multiple infarct dementia
• Myelinoclastic disorders include multiple sclerosis
• Traumatic conditions such as subdural hematoma and dementia pugilistica
• Neoplastic dementias include glioma and meningioma
• Other conditions include:
  • Hydrocephalic dementias
  • Inflammatory conditions like systemic lupus erythematosus
  • Infections like syphilis, AIDS, and CJ disease
  • Toxic conditions such as alcohol and metals
  • Metabolic disorders such as uremia and endocrine disorders
  • Psychiatric disorders like depression, mania, and schizophrenia

Reversible Dementias

• Approximately 10-15% of dementias are reversible, but most won't reverse completely and some may relapse
• They can be caused by
  • Drugs
  • Hydrocephalus
  • Subdural hematoma
  • Infections
  • Wilson's disease

Differentiating Dementia from Other Conditions

Dementia and Aphasia

• Dementia displays gradual onset, aphasia is sudden
• Decline is continuous in DAT, but not aphasia
• In DAT with diffuse brain injury, versus aphasia with focal damage
• Performance on nonverbal tasks surpasses aphasia, DAT displays simultaneous decline

Dementia and Pseudodementia

• Pseudodementia involves cognitive deficits from depression
• Depression can be an early sign of the disease
• Boundaries between depression and dementia are murky

Dementia Assessments

Purpose

• Dependent upon the individual, considering onset, language & cognitive changes, pathologies, strengths & deficits to determine assessment goal

Cognitive-Communication Evaluation

• It will test the following:
  • Attention
  • Auditory comprehension
  • Memory
  • New learning
  • Verbal expression
  • Reading comprehension
  • Written expression
  • Problem solving
  • Pragmatics

Screening Tools

Mini Mental State Examination (MMSE)

• 11 items with a total score of 30
  • A score above 23 is normal, and below 11 is severe

MoCa (Montreal Cognitive Assessment)

• Maximum score of 30
  • A score above 26 is normal
  • 22.1 suggests mild cognitive impairment
  • 16.2 is associated with Alzheimer’s Disease

Assessment Tools (Staging)

Global Deterioration Scale

• No cognitive decline is normal
• Very mild decline presents forgetfulness
• Mild cognitive decline presents early confusional state
• Moderate cognitive decline displays late confusional state
• Moderately severe decline presents early dementia
• Severe cognitive decline presents middle dementia
• Very severe cognitive decline presents late dementia

Clinical Dementia Rating

• 0 indicates healthy
• 0.5 indicates questionable status
• 1 = mild
• 2 = moderate
• 3 = severe

Verbal Fluency Test

• Healthy elderly average is 39.5 (13 words/letters)
• Mild Alzheimer's averages 15.9 (5 words/letters)
• Moderate Alzheimer's averages 4.89 (1.5 words/letters)

Arizona Battery for Cognitive Communication Disorders-2 (ABCD-2)

• Comprehensive evaluation of:
  • Mental status
  • Following commands
  • Confrontation naming
  • Story retelling delayed
  • Object description
  • Generative drawing

Possible Dementia Treatments

Experimental Drugs

Acetylcholinesterase Inhibitors

• Aricept treats all Alzheimer's stages
• Razadyne is for mild to moderate Alzheimer's
• Exelon, for mild to moderate Alzheimer's

Glutamate Receptor Antagonists

• Namenda to treat Moderate and late stages

Other treatments

• Antioxidants reduce free radicals
• Ginkgo biloba and vitamin E

Memory Patterns in the Brain

Long-Term Memory

Declarative Memory (Explicit)

• Consciously recallable facts/semantic and personal/episodic memories

Non-Declarative Memory (Implicit)

• Allows performance of learned tasks without conscious thought
• This procedural memory is less impaired in dementia

SLP Dementia Management

Direct Therapies

Reminiscence Therapy

• Semi-cued conversations regarding past events to trigger long-term/episodic memory recall

Spaced Retrieval Training

• Prompts the recall of a Target Behavior response at spaced or delayed intervals such as: - Important locations - How to call a nurse for help - Name associations with friends and family - Safe swallow and transfer techniques
• It capitalizes on the preserved non-declarative memory

Memory Prostheses

• These are external memory aids to augment memory capacity These include:
  • Memory books and wallets
  • Calendars
  • Appointment books

Indirect Therapies

Environmental Manipulations

• External memory aids include:
  • Calendars
  • Clocks
  • Family photos
  • Room labeling
  • Familiar Music
  • Limited distractions

Other Indirect Therapies

These include:

• Caregiver counseling
• Functional maintenance

SLPs Role in Dementia Management

• Diagnosing and monitoring progress
• Identifying effective means of communication and assessing efficacy of pharmacological and other therapies
• Exploring communication techniques and evaluating caregiver communication skills

Counseling Family

• It is critical to caregiver education, especially in early stages when families misinterpret behaviors

Communication Improvement

• Caregivers need instruction about communication strategies such as adjusting:
  • Topic
  • Amount of new information
  • Amount of redundancy
  • Speaking rate
  • Number of conversants
  • Complexity of syntax
  • Word choice

Dementia Management

Early Stages

• Implement environmental controls with simple routines, reminders, lists, and specific places for items
• Use checklists, cards with information, and bracelets with ID

Later Stages

• Shift management to family/caregivers
  • Educate caregivers to optimize function and communication
  • Council caregivers on the best approach for communicating

SLP Management

• Direct management includes:
  • Restorative: Limited new learning, more successful with procedural
  • Compensatory:
    • Visual cues
    • Structured environment
    • Memory books

Dysarthria

Neurologic Process of Speech Production

• Cognitive-linguistic processing organizes thoughts and converts them into verbal symbols, following language rules
• Motor speech programming organizes verbal messages for the selection and activation of speech muscles at appropriate times and intensities
• Neuromuscular execution is carried out when the CNS and PNS innervate the speech muscles

Defining Dysarthria

• Collective name for speech disorders is a result of disturbances and muscular control due to damage of the mechanisms needed (central or peripheral nervous)
• It designates problems in paralysis, weakness, or incoordination the speech

Etiology

• Neurogenic in origin due to damage in the nervous system
• Abnormal neuromuscular control which affects speed movements

Types of Dysarthria

• Flaccid
• Spastic
• Ataxic
• Hypokinetic
• Hyperkinetic
• Unilateral upper motor neuron
• The faithful matches the location of damage, and can be perceptually separate

Major Functional and Anatomic Divisions of the Speech Motor System

Direct Activation Pathway

• Also known as the pyramidal system and direct motor system
• Fiber tracts originate in the motor cortex and terminate in cranial and spinal nerve motor nuclei

Indirect Activation Pathway

• Also known as the extrapyramidal system
• It tracks from the motor cortex and synapses with other structures (basal ganglia) before terminating in the brainstem and spinal cord to form upper motor neuron system

Final Common Pathway

• This consists of cranial and spinal nerves

Structures and Functions

• Peripheral mechanisms through which all motor activity is mediated
• Final link to speech muscles containing messages from the cerebrum that are controlled and elsewhere

Components for Speech Production

• Paired cranial nerves in the phonation, resonance, articulation, and prosody of the speech
  • Trigeminal CN V
  • Facial CN VII
  • Glossopharyngeal CN IX
  • Vagus CN X
  • Accessory CN XI
  • Hypoglossal CN XII

Effects of Neural Damage

• Prevent a normalized activation of muscle
• Causes Denervation: paresis or paralysis, with unilateral or bilateral muscle atrophy, alongside diminished reflexes
• Causes excess or spontaneous motor activity on the surface of the skin (fasciculations and fibrillations)

Control Circuits

• These help to refine the motor commands like basal ganglia
• They do not having direct LMN's

Nerves, Tracts, and Pathways

• These are a collection of nerve fibers ( axons)

Classifications

• Commissural fiber tracts connect similar areas across brain hemispheres, as well as the spinal cord
• Projection fiber tracts connect higher and lower centers in brain
• Association fiber tracts join locations within same hemisphere

Important Cranial Nerves for Speech

CN V Trigeminal Nerve

• Three branches: ophthalmic, maxillary, mandibular Unilateral damage = no effect Bilateral damage = imprecise articulation

CN VII Facial Nerve

• Three branches: temporal(Facial expressions), zygomatic branch( ½ of tongue taste), cervicofacial branch(lower facial muscle)
• Unilateral damage = mild articulatory distinctions

CN IX Glossopharyngeal Nerve

• Innervates the muscle that elevates larynx during swallow (posterior ½ of tongue can cause gag reflex, sensory)
• Works with Vagus nerve, making damage result

CN X Vagus Nerve

• Divisions include:
  • Pharyngeal
  • Superior laryngeal nerve
  • Recurrent laryngeal nerve
• Damage to nerve affects:
  • Medullary
  • Extramedullary
  • Extracranial = unilateral damage
  • Intracranial damage= damage to nerves

CN XII Hypoglossal Nerve

• Damage cause weakness, atrophy, side of lesion
• Unilateral case tongue to deviate to the side of weakness

Key Components of Upper Motor Neurons

Direct Activation Pathway (Pyramidal Tracts)

• Facilitates discrete movements

Indirect Activation Pathway

• Multiple synapses

Flaccid Dysarthria & Neural Damage

• Caused by injury or malfunction of a nerve
• Lower motor damage and an offending lesion between the brainstem/spinal cord

Clinical Characteristics

• Weakness: paralysis or paresis
• Hypotonia
• Lower tone

Perceptual Clusters

• Phonatory incompetence breathiness
• Resonatory incompetence
• Prosodic Incompetence

Defining Deviant Speech

• Hypernasality is most speech cases
• Imprecise consonants

Spastic Dysarthria

• Bilateral damage to activation of the CNS (Central nervous system)

Speech Deficits

• Speech characteristics reflect a combination of: weakness & spasticity

Vocal Quality

• Laryngeal valve issues = biased towards hyper
• Pharyngeal valve= biased towards restricted closure

Selective Damage

• Can trigger spastic Paralysis

Etiology

• Vascular or from strokes
• From the likes of MS, tumors

Clinical Details

• Slowness is key due to emotional complaints
• Difficulting has regular rhythm
• Oral reflexes
• Phonetic stress

Other Types of Dysarthria

• Types of dysarthria reflect damage with other types
  • Ataxic dys = cerebellar

Hypo Kinetic

• Can cause issues such as Parkinson’s and tongue trimmers
• Patients may problems with speech volume, articulation, and prosody

Hyperkenetic

• Can happen due to motor defects from other issues

UMN Stroke

• Can happen with patients stroke/ damage etc

Motor Speech Disorders Examination

• The goal is to review what the patient has to describe
• How the patients issues are
• Establishing what the patient needs

Key Examination Elements

• Reviewing the case and knowing the history
• Completing the oral motor
• Assessing each element of the area
• Getting an acoustic readout