1.1 Background
Catatonia is a severe form of psychomotor disturbance associated with a range of general medical and psychiatric disorders. After almost 150 years, most of the existing literature relies on case reports and series. This has resulted in gaps in the epidemiology and neuropsychiatry of this condition.
1.2 Aims
In this thesis, I aim to characterise the epidemiology, neuroimmunology, structural neuroimaging findings and EEG findings in catatonia.
1.3 Methods
I conducted a narrative review of studies related to the immunological findings in catatonia and related conditions, informed by several systematic literature searches. I used anonymised electronic healthcare records from South London to further examine the epidemiology, inflammatory markers and neuroimaging of catatonia. Inpatients with catatonia were compared to inpatients without catatonia. To characterise the EEG findings, I conducted a systematic review and bivariate meta-analysis to determine its diagnostic test accuracy in determining the aetiology of catatonia.
1.4 Results
A literature review found that various viral, bacterial and parasitic infections have occasionally been reported in association with catatonia. The most commonly reported form of autoimmune catatonia is NMDAR encephalitis. Using electronic healthcare records, I found that the incidence of catatonia was approximately 1 per 10,000 person-years. Serum NMDAR antibodies were more common in patients with catatonia than in a psychiatric comparison group, but other inflammatory markers were not comparably increased. Abnormalities on structural MRI scans occurred in 34% of patients with catatonia, but there was no difference in adjusted comparisons to other psychiatric patients. Neurological and other general medical conditions in the literature were usually found to be distinguishable from psychiatric catatonia using clinical electroencephalography.
1.5 Conclusions
Catatonia remains an important problem in clinical and academic neuropsychiatry. There is promise for neuroimmunological and electroencephalographic biomarkers. Future research requires prospective design, relevant comparison groups and identification of more homogeneous subgroups
