Delirium caused by organic factors can complicate and mimic dementia. It is important to identify and treat any reversible disease process to relieve distress and improve functional level.

Investigations can aid diagnosis, especially when history and examination findings are limited. NICE advises the following tests when assessing a patient with cognitive impairment at initial presentation:

  • Routine haematology
  • Biochemistry including urea and electrolytes, calcium, glucose and LFT
  • Thyroid function test (TFT)
  • Serum vitamin B12 and folate
  • Midstream urine (MSU)

A chest x-ray, lumbar puncture, syphilis and HIV serology may be indicated by clinical findings, but should not be considered routinely. Neuroimaging can be performed electively as part of specialist assessment for patients with suspected dementia without clinical findings suggestive of acute intracranial pathology.

More information can be found in the Learning Zone session: Acute Delirium in the Elderly.

Learning Bite

Investigations are indicated to help diagnose any possible reversible element of a patient’s cognitive decline.