2021 ASM / R-0013
Neuroimaging of patients presenting with first episode psychosis: a two-year retrospective review
Keywords:
Neuroradiology brain, CT, Audit and standards, Patterns of Care
Authors:
K. L. Yaxley; Adelaide, SA/AU
DOI:
10.26044/ranzcr2021/R-0013
Results
- 91 (69%) of 132 included patients (age range 17 to 74 years) received neuroimaging with 85 receiving CT imaging and 15 undergoing MRI (9 patients received both)
- 58 of CT studies were ordered by the emergency department prior to formal psychiatric admission while 27 scans were ordered by the psychiatric treating team
- Most MRIs were ordered by the psychiatric treating team after clinical, psychiatric and laboratory test evaluation
- 40% of CT imaging and 60% of MRI imaging requests (43% of all imaging studies) were associated with an identifiable and relevant indication other than FEP (e.g. witnessed seizure activity, neurological signs, known or suspected malignancy, biochemical indication such as unexplained prolactinaemia or family history of a condition known to be associated with psychosis)
- The majority (75%) of imaging studies demonstrated no findings
- Of the remaining 25% of studies, the majority of findings were incidental (clinically non-significant) (e.g. paranasal sinus mucosal thickening, cavum septum pellucidum, calvarial osteoma, lacunar infarct)
- Clinically relevant (possible but unlikely causal link to psychosis) findings occurred in two cases:
- An arachnoid cyst (longstanding and known) located in the left middle cranial fossa of a patient who was eventually diagnosed with a non-organic psychosis
- Frontal lobe encephalomalacia and gliosis (likely post-traumatic) in a patient who was eventually diagnosed with delusional disorder
- Clinically relevant (likely causal link to psychosis) occurred in one case:
- Volume loss of heads of caudate nuclei with mild to moderate global cerebral parenchymal loss in a patient with a clinical presentation highly suggestive of Huntington's Disease (later confirmed)
- 7 imaging studies were reported to be sub-optimal due to motion artefact (e.g. agitated patient)
- The most common final discharge diagnosis was drug-induced psychosis (33%) followed by schizophrenia and unspecified non-organic psychosis (30% in total) with only one case of organic psychosis (Huntington’s Disease)
- While 58% of patients with a final discharge diagnosis of drug-induced psychosis (illicit substance or medication-induced), who might warrant less of a need for imaging, underwent CT or MRI examination compared with 74% of those with non drug-induced psychosis (e.g. schizophrenia spectrum disorders), this difference was not statistically significant (p = 0.0649)