A neurology primer

Descriptions exist prior to Hippocrates

Phrenitis ◦ Acute transient mental disorder seen in

association with medical illness, with psychomotor agitation, insomnia and disturbances of mood/perception

Lethargus◦ Somnolence, inertia, reduced response to stimuli

An acute disorder characterized by disturbances in consciousness, disorganized thinking, fluctuating course with reduced ability to focus, sustain, or shift attention

Develops over a short time

Disturbances in cognition (memory, disorientation, perceptual/spatial disturbance)

Acute confusional state Toxic/metabolic encephalopathy ICU psychosis Organic brain syndrome Hepatic encephalopathy Beclouded dementia “Sundowning”

20% of hospitalized elders 50% of hip fracture patients Annual costs ~ $8 billion dollars Results in longer hospital stays, morbidity,

mortality, & nursing home placement 32-67% of cases never detected

Romano & Engel 1959 J Chron Dis

“The physician who is greatly concerned to protect the integrity of the heart, liver, kidneys of his patient has not yet learned to have the similar regard for the functional integrity of his patient’s brain”

A syndrome with cognitive, psychiatric, and neurological manifestations

Understanding the key elements of the syndrome is the most critical skill

Remembering “laundry lists” of potential causes is not useful

Read the nursing and therapy staff notes◦ Often the consult is literally done before ever

having to see the patient Listen to families & don’t tell them their

loved one is “back to baseline” if they state otherwise

Educate families & other medical staff

Hypervigilant◦ Frequently associated with drug

intoxication/withdrawal (delirium tremens) with increased arousal and autonomic lability

Hypovigilant or “quiet delirium”◦ Somnolent, sluggish, and apathetic

Mixed forms

A disorder of attention (ability to maintain a coherent stream of thought, free of interference from external or internal stimuli)◦ Sustained attention◦ Divided attention◦ Ability to inhibit irrelevant stimuli

Disorientation, poor memory, visuospatial disturbances & language changes are in large part due to disordered attention (unless they pre-existed due to underlying dementia)

Mood changes (depression, apathy, irritability, anxiety, & mania)

Psychosis is common!◦ Suspiciousness, paranoid delusions◦ Visual hallucinations

Delirium is the most common cause of new onset psychosis in the elderly

Asterixis Action or postural tremor Impaired postural control (balance) Bowel and bladder incontinence Motor tone abnormalities (gegenhalten type

rigidity)

The neuroanatomy of attention/arousal is diffuse & vulnerable at many points

Often the first to “fall apart” when elderly patients get ill for whatever reason

Precipitating cause is seldom “in the brain itself”, such as a new stroke, brain tumor, bleed, or CNS infection

CT scans, MRI scans, lumbar punctures are seldom useful and often red herrings

If you got one, look at it (brain size, vasculopathy, hippocampal atrophy, ventricolomegaly)

If you are completely unsure, then EEG is helpful but rarely needed

Delirious patients have decompensation of other processes that rely on widely distributed neural networks (maintaining the upright posture and continence)

Not surprisingly these recover together A person’s gait/balance may be just as good

an indicator of recovery from delirium!

Attention and arousal are dependent upon widely distributed neural circuitry and therefore vulnerable to a variety of insults

The neurotransmitters acetylcholine (ACh) and dopamine seem particularly important

Anticholinergic drugs cause delirium Cholinergic agonists reverse drug-induced

delirium Lewy body dementia mimics delirium Hypoxia, hyperglycemia, thiamine

deficiency cause decreased ACh release Alzheimer’s and other dementia at

increased risk Serum anticholinergic activity correlates

with delirium severity and incidence

Dopamine agonists can cause delirium Dopamine blockade treats delirium Dopamine release increases in hypoxia Dopamine is important in prefrontal areas Dopamine density in prefrontal cortex

decreases with aging and correlates with attentional measures

Distractibility Poor persistence Tangentiality and rambling incoherence Intrusions of irrelevant information

◦ Results in inability to learn new information, solve problems or engage in goal-directed behavior

“Patient is pleasantly confused” “He kept speaking of going to the

circus, & had difficulty following directions”

Patient stated “I want off this train. I am choking”

“Patient is very sleepy, and difficult to arouse”

Patient had a “rough night, was up all night and agitated”

Digit span forwards and backwards◦ Normal forwards is 7 +/- 2◦ Backwards usually 2 less than forward

Reciting overlearned tasks◦ Alphabet ◦ Months forward, days of week

forward/backwards

Counting 1-20 forwards, backwards Continuous performance task such as the

“A” test◦Raise and lower hand in response to letter A

Writing is extremely sensitive to delirium◦Draws on many complex skills and falls apart early

Document the mental status examination including description of cognitive/affective features◦ Record some test of attention (digit span,

counting span, months forward, alphabet etc.)◦ Describe mood/behavior (irritability,

hallucinations, paranoia, apathy, mood lability, sadness, etc.)

Document some neurologic exam (asterixis, action tremor, poor balance/instability)

Studies◦ CBC, CMP, urinalysis, pulse ox/ABG, EKG◦ Physical examination◦ Chest XRAY, other body imaging◦ Sometimes drug screen, tsh, b12/folate, thiamine,

lumbar puncture, neuroimaging◦ EEG can be useful in unclear cases looking for

diffuse slowing

Medications! (perform a detailed review) Common geriatric infections (pneumonia,

urinary tract infections, abdominal infections, cutaneous)

Hip fracture Metabolic disturbances (glucose, sodium,

calcium, acid-base) Hypoxemia CHF, myocardial ischemia

Furosemide 0.22 Digoxin 0.25 Warfarin 0.12 Nifedipine 0.22 Isosorbide 0.15

Ranitidine 0.22 Theophylline 0.44 Prednisone 0.55 Codeine 0.11 Cimetidine 0.86

Correct/remove all contributing factors Provide meticulous supportive care

(feeding, mobility, continence, pressure wounds)

Engage patient/family provide reassurance Correct sensory deficits (glasses, hearing

aids, avoid complete darkness) Falls alarm, sitter, family member

Avoid too much or too little stimulation Try to improve sleep/wake cycle Avoid iatrogenesis (physical restraints) Plan for discharge, follow-up and next level

of care Document your examination findings

Antipsychotics are first line Benzodiazepines only for alcohol or drug

withdrawal states Occasionally cholinesterase inhibitors may

be useful and are likely to play an important role as new research evolves

Avoid benzodiazepines except for alcohol/drug withdrawal◦ Haloperidol recommended first line for most

0.5 mg q 3◦ Avoid older sedating antipsychotics

(anticholinergic)◦ Atypical antipsychotics

Put on standing dose if requirement is frequent and supplement with prn

Goal is to treat cognition/psychiatric dysfunction, not sedation!

Haldol generally favored◦ Can be given IM, SQ, IV, PR, PO◦ Low doses in elderly frail patients 0.5 mg initially

and then every 4 hrs◦ Avoid in parkinsonian patients (need to recognize

EPS) Increasing use of “atypical antipsychotics”

◦ Olanzapine, quetiapine, risperidone, ziprasidone

Ensure not only medical but cognitive follow up as well

Document your exam for others Anticipate it will recur in the future and try

to optimize conditions so it will not Educate families about medications, and

the syndrome of delirium

Delirium is a common, costly and morbid condition

Delirium is fundamentally a disorder of attention

Delirium is poorly recognized Many patients have unrecognized pre-

existing dementia Many patients will ultimately develop

dementia