A case for imaging in high-risk psychosis: insular pathology in first episode psychosis

To the Editor

The insular cortex (insula), centrally located in the cerebrum, is involved in sensory processing. Insular abnormalities are associated with psychosis and other psychiatric disorders (Takahashi et al., 2009). However, we found no prior case reports of psychosis and insular tumour. We report a novel case of first episode schizophrenia associated with a right insular mass, providing rationale for routine brain imaging in high-risk patients with psychosis.

Incarcerated for assault offences, a 16-year-old male presented with 12 months of worsening referential delusions, thought broadcasting, thought insertion, third-person auditory hallucinations and olfactory hallucinations – satisfying criteria for schizophrenia. He also had dysthymia and suicidal thoughts from age 11. There was no prior community psychiatric involvement. Five second-degree relatives had schizophrenia, one had suicided. There was no known family history of cerebral tumours. The patient further described 6 months of headaches with blurred vision exacerbated by cough. Physical examination, serological investigation and sleep-deprived electroencephalogram were normal. Magnetic resonance imaging revealed a right insular cortex mass (Figure 1). The consulted neurosurgeon opined the likely low-grade dysembryoplastic neuroepithilial tumour would remain relatively static and recommended surveillance monitoring.

Figure 1.

Magnetic resonance coronial and axial images showing area of flair/T2 signal abnormality 18 × 15 × 13 mm³ involving inferior and anterior aspects of the right insular cortex.

Depressive symptoms completely remitted on fluoxetine 40 mg/day. Psychotic symptoms did not respond to 8 weeks of risperidone 6 mg/day so the patient was transferred to an inpatient unit. Risperidone was switched to aripiprazole 30 mg/day, with subsequent transition to aripiprazole depot 400 mg monthly. Psychotic symptoms partially remitted, with full resolution of suicidal and homicidal ideation prior to discharge.

Adolescents with psychosis who run afoul of the law are at risk of medical neglect, due to high levels of psychiatric, social, educational and relational unmet needs (Chitsabesan et al., 2006). This case demonstrates that high-risk youth with psychosis should all receive brain imaging and assertive treatment. We suspect the insular tumour contributed to psychosis, exemplifying a broader literature that insular abnormalities are associated with psychosis (Takahashi et al., 2009). This may represent an aetiological paradigm for psychosis. Structural aberrance in the insula, the brain region responsible for integrating auditory and olfactory sensory inputs, was associated with hallucinations in these modalities. Furthermore, the tumour involved the anterior insula, understood to have a role in the neural substrate of emotion, which may explain his depressive prodrome. Due to the patient’s partial improvement, apart from future neurosurgical reasons, we thought excision should be considered if treatment-resistant psychosis emerged. However, insular surgery may itself cause psychotic symptoms (Isolan et al., 2010).