Neurology · Moderate
This case is fictional and exists for study. It describes no real patient.
78 years · female
An 78-year-old female is brought to the emergency department by her daughter due to a 2-day history of worsening confusion and disorientation. Her family reports that her symptoms fluctuate throughout the day, worsening in the evening, and she has been seeing non-existent insects on the walls. She has a history of hypertension and osteoarthritis managed with ramipril and paracetamol. On physical examination, she is inattentive and her speech is disorganized. Neurological examination reveals no focal deficits or neck stiffness. Abdominal examination demonstrates mild suprapubic tenderness to palpation.
Vital signs
- HR
- 102 bpm
- BP
- 118/76 mmHg
- RR
- 20/min
- Temp
- 38.1 °C
- SpO₂
- 96%
Examination findings
- Fluctuating level of consciousness and marked inattention
- Visual hallucinations (seeing insects)
- Mild suprapubic tenderness
- No focal neurological signs or meningism
Investigations
| White Blood Cell Count (WBC) | 14.5 10^9/L | reference: 4.0-11.0 |
| C-reactive protein (CRP) | 68 mg/L | reference: <5 |
| Serum Sodium | 138 mmol/L | reference: 135-145 |
| Urine Dipstick | Positive for Nitrites and Leukocyte Esterase N/A | reference: Negative |
Question 1 of 3
Which of the following is the most likely diagnosis?
The clinical picture of an acute onset, fluctuating course, impaired attention, visual hallucinations, and The clinical picture of acute onset, fluctuating course, impaired attention, visual hallucinations, and evidence of systemic infection with urinary localising signs (fever, tachycardia, raised WBC and CRP, suprapubic tenderness) is classic for hyperactive/mixed delirium precipitated by a urinary tract infection. Note that the positive nitrites and leucocyte esterase do not themselves establish the diagnosis: NICE NG109 and the UKHSA primary care UTI diagnostic guidance advise against using urine dipsticks to diagnose UTI in adults over 65 years, in whom asymptomatic bacteriuria is common, so a positive dipstick indicates bacteriuria rather than infection. The diagnosis here rests on the systemic and localising clinical features, and in line with NICE CG103 other precipitants of delirium — hypoxia, medication, pain, constipation, urinary retention, electrolyte disturbance, an alternative source of sepsis, and intracranial pathology such as subdural haematoma — must still be actively sought. Alzheimer's disease and vascular dementia present with chronic, progressive cognitive decline over months to years. Acute ischaemic stroke typically presents with sudden focal neurological deficits rather than isolated acute global cognitive fluctuation with systemic infective features.. Alzheimer's and vascular dementia present with chronic, progressive cognitive decline over months to years. Acute ischaemic stroke typically presents with sudden focal neurological deficits rather than isolated acute global cognitive fluctuation with systemic infective symptoms.
Teaching point: Delirium is characterized by an acute onset, fluctuating course, and inattention, commonly precipitated by systemic triggers such as urinary tract infections in elderly patients.
Question 2 of 3
Which of the following is the most appropriate initial management step for this patient's cognitive state?
The management of delirium focuses on identifying and treating the underlying precipitating cause (e.g., empiric antibiotic treatment for the suspected urinary tract infection) along with non-pharmacological measures like orientation and supportive care. Antipsychotics such as haloperidol should not be routinely given unless the patient poses a severe safety risk to themselves or others, or is in severe distress. CT head is not routinely required unless there are focal neurological signs, history of trauma, or unexplained diagnostic uncertainty. Cholinesterase inhibitors are indicated for chronic neurodegenerative conditions like Alzheimer's disease, not acute delirium.
Teaching point: The primary management of acute delirium involves treating the underlying physical trigger and applying non-pharmacological supportive interventions.
Question 3 of 3
Which clinical feature best distinguishes delirium from underlying dementia in this presentation?
An acute onset (hours to days) and a fluctuating clinical course with marked inattention are the landmark features that differentiate delirium from dementia, which develops insidiously over months to years. Both delirium and dementia can manifest with cognitive impairment and disorganized thought. A history of hypertension is a cardiovascular risk factor associated with vascular dementia but does not help differentiate between acute delirium and chronic dementia.
Teaching point: Acute onset and fluctuating symptoms are key features that differentiate delirium from chronic dementias.
Key learning points
- Delirium is an acute, fluctuating syndrome characterized by altered consciousness, inattention, and cognitive disturbance.
- Systemic infection, particularly urinary tract infection, is a frequent organic cause of delirium in elderly patients.
- Management requires addressing the underlying trigger alongside non-pharmacological environmental interventions before considering chemical restraint.
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