Catatonia, described in 1874 by K. L. Kahlbaum, is a distinct and heterogeneous neuropsychiatric syndrome, with both motoric and behavioral signs. It may be hypokinetic, hyperkinetic, or mixed and includes volitional signs, such as mutism, negativism, and automatic obedience. It was formerly relegated to a schizophrenia subtype, or considered extinct after the advent of modern psychopharmacology. Renewed interest and emerging systematic data have highlighted the frequency and pattern of catatonic presentations in psychiatric and medical settings, including in critical illness.
Historically, up to 40 signs were recognized, and most are now included in the published scales for detecting and rating the severity of catatonia. The Bush-Francis Catatonia Rating Scale (BFCRS) is widely used in both clinical and research settings, shows high inter-rater reliability and favorable sensitivity and specificity, and was validated in a mixed medical and psychiatric sample.1 The 23-item BFCRS was derived from classic descriptions of catatonia and modern diagnostic criteria. Cases are defined by the presence of 2 or more of the first 14 signs.
DSM-5 criteria require 3 or more from a similar list of 12 common catatonic signs. The BFCRS or DSM-5 items identify diverse clinical features, including motoric, behavioral, volitional, and autonomic signs. Statistical analyses identified subtypes of catatonia, including a retarded and an excited form. Malignant catatonia—a severe form with fever and autonomic instability—is uncommon but is important to identify as it may be fatal if not recognized and aggressively treated.
Despite effective treatments, patients with any form of catatonia remain at risk from serious complications such as dehydration, muscle breakdown, aspiration, or embolic phenomena. Once catatonia is recognized, these risks can be mitigated by effective treatments. Among the most studied treatment modalities, regardless of the underling etiology, prompt administration of gamma-aminobutyric acid (GABA) receptor agonists or ECT for severe or resistant cases usually relieves the symptoms and may be lifesaving.
Pathology of catatonia in the context of medical illness
The exact pathogenesis of catatonia remains unknown. Systematic examination of catatonia with genetic and brain imaging studies has been slow to develop. Familial aggregation has been reported for periodic catatonia, and preliminary evidence associated this with 15q15 chromosome.2 Single photon emission CT studies using a GABA-A ligand revealed reduced binding in areas of the frontal lobe.3 More recent studies showed increased cerebral blood flow in the supplementary motor cortex, which correlated with BFCRS severity scores, and apparent loss of frontal and insular gray matter in catatonic schizophrenia.4
Related content. Mini Quiz: Medical Catatonia
For catatonia in medical populations, the pattern or frequency of catatonic signs does not distinguish psychiatric from medical catatonia. A review of case reports on catatonia associated with brain lesions found an association with frontal and basal ganglia damage. The most recent systematic reports of medical catatonia confirm that non-localizing encephalopathies were the most common primary diagnoses associated with catatonia; a variety of non-specific EEG findings were also seen.5,6 Catatonia is generally thought to be under-recognized in the medically ill.
Catatonia and delirium
Of particular interest and potentially of great clinical significance is the relationship between catatonia and delirium. Delirium is the classic syndrome of acute brain dysfunction—with disturbed attention, awareness, and cognition—and is predictive of excess mortality, longer hospitalization, costlier care, and long-term cognitive impairment. While delirium is often assessed in critical settings such as the ICU, catatonia is not. Recognition and study of ICU catatonia have until recently been hindered by recent editions of DSM, which consistently hold that catatonia cannot be diagnosed in the presence of delirium. However, there is no clear evidence to support the exclusion.
Despite the DSM exclusion, delirium might coexist with catatonia, perhaps most prominently in the hypoactive motoric subtype of delirium. Hypoactive delirium includes decreased motor activity, decreased speech, and behavioral withdrawal—all of which map to catatonic features.
The first prospective report of catatonia with delirium was published in 2014.7 The data showed that 13% of 205 consecutive delirium cases met DSM-5 criteria for catatonia, and 32% met BFCRS criteria for catatonia. However, no treatment or outcome data were presented.