Geriatrics SC048: Common Neurological Problems In Older People Flashcards
Balance of neurologic changes with aging
Innate regenerative capacity vs Stochastic aging of nervous system
- Young: regenerative > aging
- Elderly: aging > regenerative
Regenerative:
- Growth factors release
- Neurogenesis
- Axonal growth
- Dendritic growth
Aging:
- Molecular damage (e.g. lipid peroxidation, DNA mutations)
- Energy dysregulation (e.g. insulin resistance)
- Neurodegenerative (e.g. synapse loss)
- Glial / immune alteration (e.g. demyelination)
Neurological assessment in older adults
History:
- Both patient + collateral sources who know patient well
- Ensure accuracy of information since cognitive decline, lack of awareness / insight are common
- ***Premorbid status: baseline level of cognitive function, motor skills, level of independence
P/E:
- ***Age-appropriate
- “Normal” changes in neurologic examination with aging —> not pathological
1. Eyes
- smaller pupil size + reduced reactivity (esp. with cataract)
- presbyopia (decreased near vision)
- breakdown of smooth eye pursuits with saccadic intrusions
- reduced upgaze (but downgaze may be pathological) and convergence ability of eyes
- Ears
- ↓ hearing (high frequency)
- mild ↑ in muscle tone, ↓ in muscle bulk, subtle ↓ in muscle strength
- ↓ vibration sense in distal lower extremities
- ↓ ankle jerk reflexes
- presence of primitive reflexes
- senile gait: slight stooped, slower speed, reduced tandem gait ability —> not considered pathological
Modifications in neurological P/E in severe cognitive impairment patients:
- Visual field: Count fingers —> Detect hand movement / Blink to threat
- Eye movements: Track finger —> Track examiner’s face / patient’s own finger
- Strength: Resist movement of examiner —> Maintain limbs in antigravity position after release
- UMN screen: Pronator drift —> Look at symmetry during arm rolling
- Proprioception: Detect joint movements with eyes closed —> Only Romberg test
- LL coordination: Heel-shin test —> Toe to examiner’s finger
Common neurological problems in elderly
Acute neurological emergencies:
1. Delirium
2. Seizure
Chronic neurological conditions:
1. Dementia / Cognitive impairment
2. Gait and Balance disorders (Idiopathic Parkinson’s disease)
- Seizure
- Episodes of transient neurologic change due to hypersynchronous, hyperexcited neuronal activity
- Nearly 50% of new-onset seizures occur in individuals >65 yo
- Epilepsy: **Recurrent **unprovoked seizures
Causes:
1. Provoked / Acute symptomatic
- occur with identifiable immediate cause
- not expected to recur in absence of that particular cause / trigger (e.g. hypoglycaemia, electrolyte imbalance, alcohol withdrawal)
- Unprovoked
- without an identifiable immediate cause
***Causes of Provoked seizures in elderly
-
**Acute stroke (3-9%)
- Risk factors: lobar haemorrhage, large size of stroke, cortical involvement of ischaemic stroke, hyperglycaemia during stroke
- Ischaemic stroke: mostly within **48 hours of onset
- SAH: mostly within ***hours - Other intracranial problems
- Subdural haemorrhage
- Hypoxic-ischaemic brain injury post-cardiac arrest
- Hypertensive encephalopathy
- **Trauma (Underlying cause of 4-17% of provoked seizures)
- **CNS infection - Metabolic encephalopathy
- **Hypoglycaemia / Hyperglycaemia
- **Hyponatraemia
- **Uraemic encephalopathy
- **Hepatic encephalopathy - ***Drugs / Drug withdrawal (up to 10%)
- Alcohol
- BDZ / Barbiturate withdrawal
***Causes of Epilepsy (Recurrent unprovoked seizures) in elderly
- ***Post-stroke epilepsy
- ∵ Scar in brain (aka encephalopmalacia)
- Risk factors: haemorrhage, cortical involvement, large area of stroke - ***Neurodegenerative diseases / dementia
- Intracranial lesions
- **Tumours (e.g. Metastasis)
- **Vascular malformations (rare in elderly, usually present at younger age)
Clinical features of Seizure in elderly
Seizures in elderly are difficult to recognise:
- Often atypical clinical features + easily mistaken for other conditions
- Lack of aura / preceding warning
- Lack of motor features (e.g. no limb twitching)
- Comorbid dementia (cannot tell good history)
- Misdiagnosed as delirium
—> High level of suspicion needed
Typical features:
1. Limb twitching
Atypical features:
1. Confusion, behavioural change, unresponsiveness, fluctuating consciousness
2. Sudden falls with no recall / warning
3. Recurrent events occurring in various positions / circumstances
4. Arousal from sleep with confusion / disorientation
***Approach to Seizure in elderly
- History (most important): Detailed description of event by witness, medications, substances, past medical history
- Blood test
- CBC
- ***Electrolytes (Na, Ca, Mg, PO4)
- Muscle enzymes (↑ may suggest seizure)
- Toxicology (for OTC medications)
- Prolactin (∵ propagation of epileptic activity to hypothalamic-pituitary axis (from web)) - Imaging
- ***CT / MRI to rule out structural lesions (e.g. stroke, tumours) (esp. first onset) - ***CSF analysis
- CNS infection (e.g. chronic CNS infection may present with seizure without fever) - ***EEG
***Management of Seizure in elderly
Immediate:
1. Secure airway + stabilise vital signs
2. Check glucose
3. Anti-epileptic drug (AED) (for seizure abortion if prolonged)
Long-term:
1. Long term AED
- complex decision
- based on risk factors for seizure recurrence rather than age
- major risk factors for recurrent seizure:
—> remote symptomatic etiology (e.g. neuronal dysfunction, neurodegenerative disease)
—> first seizure arising from sleep
—> epileptiform discharge abnormality on EEG
—> structural abnormality on MRI brain (which is not reversible)
First unprovoked seizure:
- Long-term AED **only for documented potential **symptomatic cause of epilepsy (e.g. stroke, TBI, tumour)
—> based upon history, abnormal neurologic P/E, relevant abnormality on brain imaging (CT / MRI) +/- epileptiform discharges on EEG
> =2 well-documented **unprovoked seizure (i.e. **Epilepsy):
- AED should be started (even without features above)
Special points to note for elderly:
- Take into account their comorbidities, adverse effect profile, drug-drug interaction before starting AED
- Started at ***very low doses and titrated gradually (in contrast to younger patients) (∵ elderly sensitive to SE)
- Delirium
- Acute confusion
- Complex neuropsychiatric syndrome
- Disturbance of consciousness with reduced ability to focus, sustain, shift attention
- Acute onset + Fluctuating course
Symptoms:
- Wide range
- Non-specific
- 1/3-2/3 underdiagnosed in clinical practice
Clinical features:
1. ***Acute onset
- abruptly over hours / days
-
**Fluctuating course
- symptoms come and go / change in severity over 24 hour period
- characteristic **lucid intervals - ***Inattention
- difficulty focusing, sustaining, shifting attention
- difficulty maintaining conversation / following commands - ***Disorganised thinking
- disorganised / incoherent speech
- irrelevant conversation / unclear / illogical flow of ideas -
**Altered level of consciousness
- **clouding, reduced clarity of awareness of environment
- but can be ***hypervigilant
Other possible symptoms:
6. Cognitive deficits (e.g. poor memory, language impairment, disorientation)
7. Perceptual disturbance (e.g. illusions, hallucinations)
8. Psychomotor disturbance
- hyperactive (agitation, vigilance) / hypoactive (lethargy, decreased motor activity) / mixed
9. Altered sleep-wake cycle (e.g. daytime drowsiness, nighttime insomnia)
10. Emotional disturbances
***Causes of Delirium
Multifactorial
- Predisposing factors (Baseline vulnerability)
- >65
- Male
- ***Baseline cognitive impairment
- Visual / Hearing impairment
- Co-existing medical conditions
- Functional dependence
- Immobility
- Pain
- Constipation
- Sleep problem - Precipitating factors (Noxious insults)
- **Drugs (toxicity, anticholinergic, sedative, narcotic, anticonvulsant, withdrawal)
- **Infection
- Intercurrent illnesses (e.g. gouty arthritis pain, COPD, chronic lung / liver disease)
- **Neurological conditions (e.g. stroke)
- **AROU / Constipation
- **Metabolic conditions (e.g. electrolytes, glucose, acute adrenal insufficiency)
- Dehydration
- Surgery (stress from operation: ortho / cardiac)
- **Pain
- Environmental issues (e.g. stranger environment)
High Vulnerability —> Low Noxious insults enough to drive into delirium
Delirium vs Dementia vs Depression (3 “D”s in elderly)
Delirium:
1. Onset: **Acute
2. Course: **Fluctuating
3. Duration: Days - Weeks
4. Consciousness: Altered (Hypo / Hyper)
5. Attention: ***Impaired
6. Psychomotor change: Increased / Decreased (Hypo / Hyperactive)
7. Reversibility: Usually
Dementia:
1. Onset: Insidious
2. Course: Progressive
3. Duration: Months - Years
4. Consciousness: Clear
5. Attention: Normal (unless severe) (i.e. can follow conversation)
6. Psychomotor change: Often normal
7. Reversibility: Rarely
Depression:
1. Onset: Insidious
2. Course: Diurnal variation
3. Duration: Variable
4. Consciousness: Generally unimpaired
5. Attention: Unaffected
6. Psychomotor change: Psychomotor slowing
7. Reversibility: Control with medications
Approach to Delirium in elderly
- History taking from informant (most important)
- Baseline cognitive function
- Recent (past 2 weeks) changes in mental status: onset + course of symptoms
- Pain / discomfort (e.g. urinary retention, constipation, thirst)
- Medication (prescribed / ***OTC / herbal (esp. BDZ, Anticholinergics, Drug-drug interaction) —> most common reversible cause (22-39%)
- Alcohol - P/E
- Head to toe
- Vitals: temp, SaO2 (infection, COPD etc.), glucose
- Neurological: focal neurological changes (stroke), meningeal signs (CNS infection)
- Signs of occult infection (joints commonly missed, bedsores), dehydration, acute abdominal pain, DVT, other acute illness
- Assess for sensory impairments (visual / hearing can precipitate delirium)
- Palpable bladder - Diagnosis of Delirium: Confusion Assessment Method (CAM: screening tool)
A + B + C / D
- A: Acute onset + Fluctuating course
- B: Inattention
- C: Disorganised thinking
- D: Altered consciousness - Investigations
- Blood: CBC, Electrolytes (Na, Ca), Glucose, LRFT, TFT
- Drug concentration (e.g. digoxin, AED), NH3 concentration (chronic liver disease), Vit B12, Cortisol (adrenal insufficiency), ABG (hypercapnia: common cause of delirium)
- Urinalysis (occult UTI)
- ECG (acute MI)
- CXR / AXR (IO)
- CT / MRI brain (stroke, haemorrhage, tumours)
- EEG (seizure)
- LP as indicated
Management of Delirium
- Treat underlying cause
- Non-pharmacological (first strategy)
- Drug adjustment
- Address acute medical issues
- Reorientation strategies
- Maintain safe mobility
- Normalise sleep-wake cycle
Do:
- Provide environmental + personal orientation
- Ensure continuity of care
- Encourage mobility
- Reduce medication but ensure adequate analgesia
- Ensure hearing aids + spectacles are available and in good working order
- Avoid constipation / ROU
- Maintain good sleep pattern
- Maintain good fluid intake
- Involve relatives and carers
- Avoid complications (immobility, malnutrition, pressure sores, over sedation, falls, incontinence)
- Liaise with old age psychiatry service
Do NOT:
- Catheterise (if possible)
- Use restraint
- Sedate routinely
- Argue with patient
- Antipsychotic, Sedatives (for symptom control / confusion)
- start with low dose + titration until effect achieved
—> **Haloperidol 0.25-0.5mg PO/IM BD (Atypical antipsychotic: Quetiapine, Risperidone close in effectiveness)
- sedation of severely agitated patients in whom interruption of essential medical therapies (e.g. mechanical ventilation, dialysis catheter) / self-harm
- treating distressing / dangerous behavioural disturbances (e.g. in patients with extremely distressing psychotic symptoms e.g. delusion, hallucination)
- can prolong duration of delirium + associated cognitive impairments, worsen clinical outcome
—> **no evidence that improve prognosis (only improve symptom)
—> might switch patient from hyperactive to hypoactive
—> worsen cognitive impairment
—> complicate ongoing assessment of mental status (not sure if patient recovering)
—> impair patient’s ability to understand / cooperate with treatment
—> increase fall risk
—> impair rehabilitation progress
- Dementia / Cognitive impairment
DSM5:
1. Dementia (aka **Major neurocognitive disorders)
- Significant cognitive decline from previous level of performance in **>=1 cognitive area (memory, language, attention, executive function, perceptual-motor and social recognition)
* **AND
- Interference with independence in everyday activities
- Mild cognitive impairment (MCI) (aka **Mild neurocognitive disorder)
- Significant cognitive decline from previous level of performance in **>=1 cognitive area (memory, language, attention, executive function, perceptual-motor and social recognition)
* **WITHOUT
- Interference with independence in everyday activities
***MUST rule out active delirium before making diagnosis of dementia
Causes:
Primary:
1. **Alzheimer’s disease (most common)
2. **Vascular dementia (2nd common)
3. Mixed (AD + VD)
4. Frontotemporal dementia (uncommon)
5. Lewy body dementia (uncommon)
6. Parkinson’s disease dementia (uncommon)
Secondary:
1. Secondary causes of dementia (e.g. tumour, trauma, normal pressure hydrocephalus (NPH))
