Organic Mental/Neurocognitive disorders

• 1% in the general population
• Very Common – about 20% of med/surg inpatients (30%+ if elderly)
• 30% of Adult Burn Patients
• 40% of demented patients are delirious on admission
• Predisposing Factors:
  • Old and young age
  • Post-cardiotomy
  • Burns
  • Pre-existing brain damage
  • Drug withdrawal states
  • AIDS

• Infections: Encephalitis, meningitis, syphilis, HIV, sepsis
• Withdrawal states: Psychoactive subs, drugs
• Acute metabolic: Acidosis, alkalosis, electrolyte derangements, liver failure, kidney failure
• Trauma: Head injury, postoperative states, burn
• CNS pathology: Abscess, hemorrhage, hydrocephalus, subdural hematoma, infection, seizures, stroke, tumors, vasculitis
• Hypoxia: Anemia, CO poisoning, hypotension, respiratory failure, heart failure
• Deficiencies: Vitamins B1 (thiamine), B3 (niacin), B9 (folate), and B12 (cyanocobalamin)
• Endocrinopathies: Thyroid abn, parathyroid, and adrenal glands, hyperglycemia or hypoglycemia
• Acute vascular: Severe hypertension, stroke, arrhythmia, shock
• Toxins or drugs: Medications, illicit drugs, pesticides, solvents
• Heavy metals: Lead, manganese, mercury

• Most patients recover quickly, and a few need specific treatment.
• Symptoms worsen at night.
• Cause not found in about 30% of cases.

• Disordered thinking (thought disorder)
• Emotional lability
• Language impairment (receptive or expressive)
• Illusions, delusions, and hallucinations (positive psychotic symptoms)
• Reversal of sleep‐wake cycle
• Inattention (clouding of consciousness)
• Unaware and disoriented
• Memory deficits

Clinical Features

Common symptoms of delirium include:

• Waxing and waning levels of consciousness
• Poor attention and disorientation
• Disturbed memory (long and short term)
• Psychosis
• Sleep dysregulation
• Fearfulness with agitation and aggression
• Seriously impaired insight and judgment

Hyperactive delirium: Increased psychomotor activity, agitation, restlessness

Hypoactive delirium: Slow motor activity, apathy, withdrawal

• The Mini-Mental Status Examination (MMSE)
• Montreal Cognitive Assessment (MoCA)
• Confusion Assessment Methods
• Memorial Delirium Assessment Scale

Interventions

• Pharmacological
• Non-Pharmacological:
  • Physical:
    • Hydration
    • Nutrition
    • Oxygen
    • Restraint
  • Environmental:
    • Safety
    • Prevent over/under stimulation
  • Cognitive:
    • Treat hallucination
  • Psychological:
    • Medication (low dose, high potency drug)

Principles of Management of Delirium

1. Treat the underlying cause or causes.
2. Maintain adequate hydration and nutrition.
3. Rest, reassurance, and reorientation.
4. Nurse in the same room, with the same staff (if possible), and have relatives or friends present. Nurse in a well-lit environment/should be dim at night, avoid overstimulation.
5. Administer psychotropic medication only in extreme disturbance. Physical restraint may be an alternative. Neuroleptics such as Haloperidol or Risperidone may be prescribed acutely, in small doses to reduce agitation/behavioral problems. Alternatives include benzodiazepines. Oral medication preferred, i.m. only if absolutely necessary.

• Primary versus secondary based on the pathophysiology leading to damaged brain tissue
• Cortical versus sub-cortical depending on the cerebral location of the primary deficits
• Reversible versus irreversible depending on optimal treatment expectations
• Early (before age 65) versus late onset

Differences between Cortical and Subcortical Dementia

Features	Cortical Dementia	Subcortical Dementia
Site of lesion	Cortex (Frontal and tempero-parieto-occipital association areas and hippocampus)	Subcortical grey matter (thalamus, basal ganglia, brain stem)
Examples	Alzheimer's disease Pick's disease	Huntington's chorea Parkinson's disease
Severity	Severe	Mild to moderate
Motor system	Usually normal	Flexed Extended posture, Tremors, chorea slowed speed
Other features	Depression uncommon, Severe aphasia, amnesia, agnosia	Delusions, depression, rarely mania
Coordination	Normal	Impaired

• Primary/Degenerative - Irreversible
  • Alzheimer’s
  • Pick’s
  • Huntington's
  • CKJ (Creutzfeldt-Jakob)
  • Frontal lobar
  • Lewy-body
  • Parkinson’s
  • Multiple sclerosis
  • Wilson’s disease
• Secondary - Reversible
  • Vascular
  • Infective
  • Traumatic
  • Neoplasm
  • Inflammatory
  • Metabolic
  • Endocrine
  • Hydrocephalus
  • Nutritional deficiencies

Aetiology According to Region of the Brain

• Cortical: Alzheimer's, frontotemporal, CKJ
• Sub-cortical: Huntington’s disease, Parkinson's, focal thalamic and basal ganglia lesions, multiple sclerosis
• Mixed: Vascular, Lewy body dementia, neurosyphilis

• Problems with short-term memory
  • Appointments
  • Conversations
  • Events
  • Repeating stories
• Difficulty remembering names, faces
• Forgetting acquaintances and friends
• Trouble making sense of language
  • Trouble finding the right word
  • Difficulty naming objects
  • Understanding complicated instructions
• Trouble doing familiar things
  • Driving, banking
  • Cooking, cleaning, laundry
  • Dressing, bathing
• Confusion in unfamiliar places
• Getting lost
• Personality changes
• Easy to anger, emotional
• Suspicious
• Seeing or hearing things that aren’t there

• Always associated with cognitive disturbances and functional impairments
• Visuospatial impairments and behavioral disturbances are usually seen as well
• Specific symptoms will vary by the type of dementia

Memory Impairments

• Difficulty learning or retaining new information (repeated conversations)
• Information retrieval deficits (can’t recall names, list generation deficits)
• Personal episodic memory impairment (misplacing items)
• Declarative (semantic) memory (FACTS) > Procedural (implicit) memory (HOW)

Language Deficits

• List-generation deficits (especially in AD)
• Word-finding difficulties (naming problems)
• Verbal fluency deficits
• Less complex sentence structure
• Relatively preserved auditory comprehension (can understand directions)

Visuospatial Impairments

• Visual recognition impairments (trouble recognizing familiar faces - CAPGRAS syndrome possible)
• Spatial deficits (getting lost in familiar surroundings, 3-D drawing deficits)

Executive Function Impairments

• Planning, predicting, correlating, abstracting –> Frontal lobe Function
• Taking multiple threads of information and processing it to make a decision (Trails B testing)
• Often the first impairment noticed in highly educated/intelligent people
• Pronounced deficits often seen in FTDs (Frontotemporal Dementias) before overt memory impairment

Functional Impairments

• Deficits appear first in IADLs (managing finances, driving, shopping, working, taking medications, keeping appointments)
• Eventually problems with ADLs (feeding, grooming, dressing, eating, toileting)
• Rate and specific pattern of loss will vary by individual and somewhat by diagnosis

NB: Functional impairment and performance on cognitive testing may not correlate strongly early in the course of dementia

ADL (Activities of Daily Living)

Behavioral Symptoms

• Often the main focus of treatment. Inability to manage these symptoms is highly correlated with institutional placement.
• PERSONALITY CHANGE: occurs early
  • Passivity (apathy, social withdrawal)
  • Disinhibition (inappropriate sexual behavior or language)
  • Self-centered behaviors (childishness, loss of generosity)

Agitation

• Very common
• Worsens as the illness progresses
  • Verbal aggression (25%)
  • Physical aggression (30%)
  • Non-aggressive behaviors such as wandering and pacing (25-50%)

Other Associated Features

• Depression (40-50%) - especially in AD & VD
• Psychosis
  • Delusions (30-60%)
    • Paranoid type (theft, infidelity)
    • Misidentification type (Capgras, etc.)
  • Perceptual disturbances (20-40%) - often visual, common in LBD
• Sleep Disturbances (>50%) - insomnia, sleep-wake cycle problems. This plus wandering and aggression are highly correlated with caregiver burnout

Dementia	Depressive pseudodementia
Patient rarely complains of the cognitive impairment.	Patient usually always complaints about the impairment.
Patient emphasizes achievements.	Patient emphasizes disability.
Patient appears unconcerned.	Patient communicates distress.
Patient makes mistake on examination.	Don't know answer are frequent.
Recent memory impairment found on examination.	Recent memory impairment rarely found on examination.
Consistently poor performance on similar tests.	Marked variability in performance on similar tests.
History of depression uncommon.	Past history of maniac depressive episodes may be present.

Comparison
Typical Aging:	Symptoms of Dementia:
Complains about memory loss but can provide examples of forgetfulness.	May complain of memory loss if asked; unable to recall specific instances.
Occasionally searches for words	Frequent word-finding pauses, substitutions.
May have to pause to remember directions, but doesn't get lost in familiar places.	Gets lost in familiar places and takes excessive time to return home.
Remembers recent important events; conversations are not impaired.	Notable decline in memory for recent events and ability to converse.
Interpersonal social skills are at the same level as they've always been.	Loss of interest in social activities; may behave in socially inappropriate ways.

• Most have insidious onset with progressive decline over many years
• Some are fulminate (e.g., CJD)
• Some may remit spontaneously or with treatment (e.g., Thyroid disease, B12 def.)
• AD - Predictable progression which is the reverse of development. Typically live 4 -10 years after diagnosis and often have symptoms 3-4 years before diagnosis. Women usually outlive men.*
  • Ann Intern Med (2004) Average survival after diagnosis of AD: 5.7 years for women, 4.2 years for men
• VD - May show step-wise progression. Shorter course than AD. Often see focal findings

• Age
• Family history
• Down’s syndrome (trisomy 21)
• Head Trauma (especially late in life)
• Female gender (mixed results: age bias and possible higher 'clinical' expression in women)
• Ethnicity (Caucasians have the lowest risk)
• Late-onset depression (after age 65)
• Mild Cognitive Impairment (MCI)
• Syndrome X, HTN

ICD Diagnosis

1. Evidence of decline in both memory and thinking, sufficient enough to impair personal activities of daily living.
2. Memory impairment typically affects the registration, storage, and retrieval of new information (recent memory), but previously learned material (remote memory) may also be lost, particularly in later stages.
3. Thinking is impaired, the flow of ideas is reduced, and the reasoning capacity is also impaired.
4. Presence of clear consciousness. (Consciousness can be impaired if delirium is also present).
5. Duration of at least 6 months.

Note: No one test can diagnose dementia. Memory tests or brain scans alone are not enough. Diagnosis is made after combining the medical assessment and memory tests.

Aspects of Differential Diagnosis

• Is it an Organic or a Functional cause?
• Organic…
  • The cognitive disorder preceded the mood or other disorder.
  • Cognitive defects occur in specific areas of intellectual function.
  • Neurological signs.
  • The presence of symptoms seldom found in non-organic disorders, such as visual hallucinations.
• Functional…
  • By exclusion of organic causes.
  • By finding positive evidence of psychological etiology.

STEPS TAKEN IN A PROBLEM-ORIENTED APPROACH TO THE MGT OF DEMENTIA

1. Set time for review
2. Carry out review: assess effectiveness of management plan and reassess problems and priorities

DIPS: a structured approach to the management of dementia

• Dementia: treat the cause where possible
• Illness: treat concurrent illness
• Problem list: tackle each major problem
• Support the supporters: care for the carers

(A recent study found that patients with caregivers who had a realistic understanding of the prognosis and complications of late dementia were less likely to receive aggressive treatment at the end of life)

Other Aspects of Management

• Environmental: Nurse in a calm and familiar environment with minimal changes and follow routines.
• Psychological treatments: Aromatherapy, massages, reality orientation, music therapy, art therapy, and memory training.
• Treat exacerbating factors: Infections, electrolyte imbalance, comorbid physical illnesses.
• Medicolegal considerations: Risk of driving, capacity to make decisions, need for palliative care in advanced cases.

Dementia Pharmacological Management

• Cholinesterase inhibitors for cognitive symptoms, improvement in quality of life – useful for mild to moderate disease:
  • Donepezil 5-10 mg/day
  • Galantamine 4 – 8 mg BD (16-24 mg/d)
  • Rivastigmine 1.5 – 3 mg BD (6-12 mg/d)
• Antipsychotics for behavioural problems
• Antioxidants
• NSAIDs & Folic acid
• Memantine (NMDA glutamate receptor antagonist)
• Hormone replacement therapy or statins may reduce the risk of dementia

Preventive Measures

• Reducing smoking, alcohol abuse, and recreational drug abuse
• Participating in mentally stimulating memory training activities
• Staying physically and socially active
• Eating healthy
• Maintaining a regular exercise routine
• Adequate and quality sleep
• Treat medical problems appropriately (cholesterol, DM, HBP)

Planning for the Future

• Involve family and close friends and explain:
  • The diagnosis
  • The person’s memory will decline
  • The person will need more help over time
• Plan for the future while the person can still talk about what they prefer:
  • Living Arrangements
  • Health Care:
  • Substitute Decision Maker – who will make medical decisions if the person becomes unable
  • Advance Directives – a written document about medical preferences

Finances

• Understand their financial situation:
  • Bank accounts
  • Income
  • Assets (home)
  • Debt
  • Will
• Power of Attorney:
  • Assigns a person to take over finances if they become unable to manage

Wandering

• Pacing around
  • Can get lost or fall
• Ways to manage
  • Close supervision
  • Provide a safe place to wander (mall)
  • Provide alternative activities
  • Environment control
    • Lock doors
    • Remove hazards
  • Maintaining contact
    • Wandering registry: Safely Home, GPS, Cell phones

Tips For Caregivers: Safety Measures at Home

• Locks on medicine cabinets
• Locks for stove
• Keep furniture simple and in the same place to prevent falls
• No electrical appliances in the bathroom
• Help the person with personal care
• Ask for a home therapist visit from your doctor
• Home safety and equipment suggestions
• Be patient with repetitive behaviors
• The person doesn’t realize what they are doing
• Speak slowly, using one idea at a time
• Emotional outbursts, suspicion may be present
• Try to distract rather than argue
• Suggest a cup of tea or a walk
• If you are too frustrated, take a break
• Go for a walk
• Call a friend

Care Tips for Caregivers

• Exercise and socialize
• Take care of own medical problems
• Encourage to consider respite care and outside supports
  • Respite through care facilities
  • Home Care
  • Adult Day Centers
• Encourage to connect with other caregivers through the caregivers support groups

• Commonest, gradually progress over time
• Marked reduction of neurons, appearance of neurofibrillary tangles and beta amyloid plaques in hippocampus & cerebral cortex
• Degeneration of cholinergic neurons in basal forebrain

Alzheimer’s Type

• Early onset
  • Onset before age 65
  • Familial / usually AD mutation
  • Relative rapid deterioration
  • Aphasia, Agraphia, Alexia, Apraxia
  • Positive family history or Down’s syndrome
• Late onset
  • Slow progression, no insight, confabulations, and memory impairments
  • Less familial influence

The Genetics of Alzheimer’s Disease

• Presenilin 2 gene (chromosome 1)
• Presenilin 1 gene (chromosome 14)
• Beta amyloid precursor protein gene (chromosome 21)
• Apolipoprotein E gene (chromosome 19/late onset)
• ‘Ubiquilin 1’ polymorphisms (chromosome 9)

Factors Associated with Diminished Survival in Alzheimer's Dementia

• Parietal lobe damage (as evidenced by parietal lobe signs or decreased density on CT scan)
• Being male
• Age of onset of less than 65 years
• Prominent behavioral abnormalities (such as irritability and wandering)
• More severely impaired cognitive function (in particular evidence of apraxia)
• Depression observed by a rater
• The absence of misidentification phenomenon (i.e., misidentification appears to be protective despite its association with younger age)

• 2nd commonest after Alzheimer’s
• Multi-infarct dementia & Binswanger’s disease are types
• About 10-15% of dementia
• Abrupt onset
• Stepwise progression
• Associated features
  • Hypertension or cardiovascular disease
  • Transient episodes of clouded consciousness
  • Relatively well-preserved personality
  • Emotional lability

Risk Factors for Vascular Dementia

• Family history or personal history of HTN/cardiovascular disease
• Polycythemia
• Coagulopathies
• SCDx (Subclinical cerebrovascular disease)
• Valvular disease
• Carotid artery disease
• Smoking
• Diabetes mellitus (DM)
• Hyperlipidemia

• Circumscribed atrophy involving the frontal and anterior temporal lobes.
• Usually of younger onset age
• Progressive development of behavioral and personality change and/or language impairment.
• Predominant anti-social behavior – disinhibition, appetite change, and language problems
• Alzheimer's type neuropathology may be present
• Very sensitive to psychotropic drugs: if required, use with caution

3 Fronto-Temporal Dementia Clinical Syndromes:

• Fronto-temporal dementia – problem of behavior and executive functioning. Antisocial features, personality change (R > L)
• Semantic dementia – naming and perceptual deficits
• Non-fluent progressive aphasia - deficits in language and speech

Other features:

• Tau, ubiquitin inclusions present
• Dementia without distinctive histopathology
• Associated with ALS (amyotrophic lateral sclerosis)

• Distinct from dementia with Lewy bodies
• Loss of pigmented dopaminergic cells in the SN
• Cardinal features: rest tremors, bradykinesia, rigidity, and postural abnormalities
• Risk of dementia is 6X higher in PD patients, especially in those with severe motor symptoms, older subjects, and those with hallucinations
• Cholinergic mechanisms involved in pathogenesis
• Antipsychotics should be avoided but if needed, use quetiapine/clozapine

• The prognosis depends on the underlying cause
• Youth age of onset usually means poorer prognosis
• Alzheimer’s disease is usually fatal within 10 years of diagnosis
• Vascular dementia has a worse prognosis, with sudden stepwise deterioration and risk of sudden death from stroke

Amnestic disorder is characterized by prominent memory impairment relative to expectations for age and general premorbid level of cognitive functioning. It represents a decline from the individual’s previous functioning and is in the absence of other significant cognitive impairment.

Clinical Features:

• Deficit in acquiring, learning, and/or retaining new information
• Inability to recall previously learned information
• No disturbance in the level of consciousness
• Remote Confabulation
• Apathy
• Lack of initiative, emotional blandness

Amnestic Syndrome

Korsakov’s Syndrome: Prominent disorder of recent memory. No intellectual impairment or impaired consciousness.

Korsakov’s Syndrome:

• Prominent disorder of recent memory
• No intellectual impairment or impaired consciousness

Insight is partially impaired.

• Peripheral neuropathy

Wernicke’s Encephalopathy: An acute syndrome with impairment of consciousness, memory defect, disorientation, ataxia, peripheral neuropathy, and ophthalmoplegia.

Wernicke-Korsakov’s Syndrome:

• Amnesia and confabulations
• Atrophy of mamillary bodies

Aetiology

• Lesion in the posterior hypothalamus
• Bilateral hippocampal lesions
• Damage to mammillary bodies

Causes:

• Alcohol abuse = Vitamin B1 (thiamine deficiency)
• Severe hypoxia
• Vascular lesion
• Encephalitis
• Tumor in the third ventricle
• Thiamine deficiency
• ECT (Electroconvulsive therapy)
• Carbon monoxide poisoning
• Hypoxic brain injury
• Multiple sclerosis

Clinical Features

• Recent memory severely impaired.
• Semantic memory is spared.
• Disorientation in time.
• Attention and immediate recall are intact.
• Praxis/function is intact.
• Confabulation >>> detailed account of recent activities turn out to be inaccurate.

If due to vitamin deficiency, give vitamin supplements.

Prognosis:

Chronic presentation but better if it's due to vitamin deficiency.

Clinical Features

• Behaviour:
• Disinhibited, overfamiliar, tactless, facetious humour.
• Patients are overtalkative, make inappropriate jokes, and disregard the feelings of others.
• Mood: Euphoric. Pseudo-depressive changes.
• Concentration, attention & insight: Impaired.

Organic mood disorders

• Neurological disease( multiple sclerosis)
• Endocrine Disorder (Cushing’s disease)

These can present as depression, mania or anxiety

Medical Conditions That Cause Anxiety

• Thyrotoxicosis
• Hypoglycemia
• Pheochromocytoma
• Carcinoid syndrome
• Drug intoxication
• Drug withdrawal
• Mitral valve prolapse
• Temporal Lobe Epilepsy (TLE)
• Supraventricular tachycardia
• Coronary artery disease
• Asthma and chronic obstructive lung disease

• Thyrotoxicosis
• Hypoglycemia
• Pheochromocytoma
• Carcinoid syndrome
• Drug intoxication
• Drug withdrawal
• Mitral valve prolapse
• Temporal Lobe Epilepsy (TLE)
• Supraventricular tachycardia
• Coronary artery disease
• Asthma and chronic obstructive lung disease

Normal Pressure Hydrocephalus

Obstruction in the subarachnoid space or stenosis of the aqueduct.

Clinical Features:

• Progressive memory impairment
• Slowness
• Unsteadiness of gait (broad-based)
• Urinary incontinence (Hakim triad / tetrad)

50% of cases are of idiopathic origin.

Treatment:

Ventriculo-peritoneal shunt operation to improve the circulation of cerebrospinal fluid (CSF).

Head Injury

Acute psychological effects include:

• Impairment of consciousness
• Delirium
• Post-traumatic amnesia of more than 24 h, followed by persistent cognitive impairment
• Personality change:
  • Severe damage to frontal lobe
  • Irritability
  • Loss of spontaneity and drive
  • Reduced control of aggressive impulses
• Emotional symptoms:
  • Anxiety and depression
  • Headache
  • Poor concentration
  • Insomnia

Assessment

• Neurological signs and physical disability
• Any neuropsychiatric problems and their future course
• Social circumstances, social support, and the possibility of return to work

Management

• Physiotherapy
• Try to minimize disability
• Deal with specific cognitive deficits

Cerebrovascular Disease

Cognitive defects:

• Dementia
• Dysphasia
• Dyspraxia

Personality changes:

• Irritability
• Apathy
• Lability of mood
• Failure to cope with everyday problems (catastrophic reaction)

Depressed mood:

• Psychological reaction to handicap
• Direct consequence of any localized brain damage

Treatment

Antidepressant for depression

Cerebral Tumor

Fast-growing tumor: Delirium

Slow-growing tumor: Dementia

Multiple Sclerosis

Depression or elation.

Psychosis

Dementia

Disturbance of higher cortical functions

Prognosis is worse in males and with early disability

Transient Global Amnesia

Unknown cause

Middle or late life

Occasional

Abrupt episodes of unusual behaviour and global loss of recent memory for several hours

Patient alert & responsive

Unable to understand his experience

Complete recovery except for amnesia of the episode

No specific treatment

Epilepsy

Association between epilepsy and psychological problems of epileptic individual:

• Effect of stigma & social restriction
• Psychiatric disorder due to the cause of epilepsy:
• If due to brain damage >> intellectual impairment & personality problems
• Behavioural disturbance:
• Before: tension, irritability, depression
• During: complex partial seizure
• After: automatism

Psychiatric Disorders Associated with Epilepsy

For example, depression.

Psychiatric Problems of Treatment

For example, side effects of anticonvulsant drugs.

Seizures as Medication Side Effects

For example, antipsychotics lowering seizure threshold.

Psychiatric Disorder Masquerading as Epilepsy

For example, pseudoseizures.

Behavioral Disturbance Associated with Seizures

Preictal Prodromal States and Mood Disturbance: Various states and disturbances before the onset of a seizure.

Ictal Mood Disturbance, Hallucinations, Automatisms, Altered Awareness: Mood changes, hallucinations, repetitive unconscious behaviors, and altered consciousness during a seizure.

Postictal Delirium, Psychosis, Todd’s Paresis: Delirium, psychosis, and temporary neurological deficits (Todd's paresis) following a seizure.

Interictal Disorders

• Cognitive Impairment: Impairment in cognitive functions between seizures.
• Personality Disorder: Persistent disturbance in personality functioning.
• Aggressive Behavior – Episodic Dyscontrol Syndrome: Episodes of unprovoked aggression or violent outbursts.
• Sexual Dysfunction: Impaired sexual function.
• Increased Self-Harm & Suicide: Higher risk of self-harm and suicidal tendencies.
• Psychoses: Loss of contact with reality, including hallucinations and delusions.
• Depression: Persistent feelings of sadness and loss of interest or pleasure.
• Antisocial Behavior: Behavior that violates societal norms and rights of others.

Movement Disorders

Three D's are: Dyskinesia, Depression, Dementia

Movement Disorders:

• Parkinson’s Disease
• Huntington’s Chorea
• Wilson’s Disease
• Basal Ganglia Calcification

HIV/AIDS

Clinical Presentations: Depression, suicide, mania, anxiety, chronic pain, psychosis, dementia

HIV Associated Dementia (HAD):

About 30% develop HAD, and mean survival after diagnosis is 6 months. Associated with full-blown AIDS, it presents with slower mental processing, impaired executive function, and difficulty learning new information, which are among the most common early signs.