What is the recommended approach for assessing altered mental status in an adult or geriatric patient with potential neurological or psychiatric conditions, such as dementia, delirium, or traumatic brain injury?

Sensorium Assessment in Adults and Geriatric Patients

Immediate Bedside Assessment

Begin with objective quantification of consciousness level using validated scales: the Glasgow Coma Scale (GCS) for general assessment or the Richmond Agitation Sedation Scale (RASS) for patients with varying arousal states, as these provide standardized, reproducible measurements critical for tracking clinical trajectory. 1

Initial Vital Parameters and Point-of-Care Testing

• Fingerstick glucose immediately to exclude hypoglycemia/hyperglycemia, which are among the most common reversible causes of altered mental status 1, 2, 3
• Oxygen saturation measurement to identify hypoxia 2, 3
• Core temperature assessment to detect hypothermia 2, 3
• Vital signs including orthostatic measurements in hypertensive patients over 50 years 2
• Electrocardiogram to assess for atypical myocardial ischemia, particularly in elderly women who may present without chest pain 2

Structured Cognitive Assessment

For Acute Altered Mental Status (Delirium Suspected)

When time is limited, use rapid screening tools that can be completed in under 5 minutes: Memory Impairment Screen (MIS) plus Clock Drawing Test (CDT), Mini-Cog, AD8, or the four-item MoCA (Clock-drawing, Tap-at-letter-A, Orientation, Delayed-recall) 1

When more time permits (10-15 minutes), use comprehensive screening: Mini-Mental State Examination (MMSE), Modified Mini-Mental State (3MS), or Rowland Universal Dementia Assessment Scale (RUDAS) 1

Critical Distinction: Delirium vs. Dementia

• Delirium is a medical emergency with mortality rates twice as high when missed 1, 2, 3
• Delirium features: acute onset (minutes to days), fluctuating course throughout the day with lucid intervals, inattention as cardinal feature 1
• MMSE lacks sensitivity for mild cognitive impairment; use MoCA when mild impairment is suspected or when MMSE is "normal" (24+/30) but clinical concern persists 1

Essential Informant-Based Assessment

Obtain collateral history from a reliable informant using validated tools, as this is essential and increases diagnostic accuracy when combined with patient assessment 1, 4

Recommended Informant Tools

• Neuropsychiatric Inventory-Questionnaire (NPI-Q) for behavioral and psychological symptoms including depression, anxiety, apathy, agitation 1, 4
• AD8 or Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) for cognitive changes 1
• Pfeffer Functional Activities Questionnaire (FAQ) or Disability Assessment for Dementia (DAD) for functional autonomy 1

This approach is particularly critical when patients are uncooperative, as lack of cooperation itself may indicate delirium, advanced dementia, or severe depression 4

Systematic Evaluation for Underlying Causes

Laboratory Workup

• Comprehensive metabolic panel focusing on sodium, glucose, renal function, calcium 2, 3
• Complete blood count to assess for anemia or infection 2, 3
• Thyroid function in elderly patients with new psychiatric symptoms 2, 3
• Urinalysis (urinary tract infection is the most common infectious precipitant in elderly patients) 3
• Toxicology screen including alcohol level 2

Medication Review

Polypharmacy is a major contributor to delirium in the elderly; specifically review anticholinergic medications, sedatives, and narcotics 1, 2, 3

Neuroimaging Decision Algorithm

Non-contrast head CT is usually appropriate as first-line imaging when: 1, 2, 3

• Focal neurological deficits present
• Lower Glasgow Coma Scale score
• Significantly elevated blood pressure
• History of trauma or fall
• Anticoagulant use
• Suspected intracranial pathology

Neuroimaging has low diagnostic yield (5-6.4%) in the absence of focal deficits or trauma signs 3

MRI brain without contrast is second-line when initial CT is unrevealing but clinical suspicion for stroke remains high, or when occult pathology is suspected 3

High-Risk Populations Requiring Enhanced Vigilance

Four factors strongly associated with delirium in the emergency department: 2

• Nursing home residence
• Pre-existing cognitive impairment
• Hearing impairment
• History of stroke

Medical conditions requiring proactive cognitive screening: 1

• Recent stroke or transient ischemic attack
• Late-onset depressive disorder
• Untreated sleep apnea
• Recent episode of delirium
• First major psychiatric episode at advanced age
• Recent head injury
• Parkinson's disease

Critical Pitfalls to Avoid

• Do not assume "no stroke" without proper evaluation—small vessel disease and lacunar infarcts may not present with obvious focal deficits 2
• Do not forget nonconvulsive seizures, which require EEG rather than imaging for diagnosis 1, 2
• Do not overlook drug or alcohol withdrawal even without obvious intoxication 1
• Do not miss orthostatic hypotension by only measuring seated blood pressure—obtain lying and standing measurements 2
• Do not delay assessment in patients with warning signs including missed appointments, showing up at incorrect times, difficulty following instructions, or new-onset behavioral changes 1

Documentation Requirements

Combine cognitive tests with functional screens and informant reports, as this combination significantly improves diagnostic accuracy compared to any single method 1, 4

Document specific observed behaviors, informant-reported changes, temporal course, impact on daily functioning and safety, and response to interventions 4