Since its initial description by Kahlbaum (1828-1899)1 over a century ago, catatonia has been associated with psychiatric, neurologic, and medical disorders. Contemporary authors view catatonia as a syndrome of motor signs in association with disorders of mood, behavior, or thought. Some motor features are classic but infrequent (eg, echopraxia, waxy flexibility) while others are common in psychiatric patients (eg, agitation, withdrawal), becoming significant because of their duration and severity. Catatonia may be subtle and overlooked, which perhaps accounts for former reports suggesting a declining incidence. With renewed recent attention, catatonia is increasingly recognized; several reports of systematic screening in psychiatric admissions find an incidence of 7% to 17%.2
After Kahlbaum, catatonia was associated with schizophrenia by Kraepelin (1855-1925) and Bleuler (1857-1939). This notion continued in the DSM series, despite reports linking catatonia to affective disorders3,4 or systemic/toxic reactions.5,6 DSM-IV now recognizes catatonic schizophrenia (295.3x), catatonia due to a general medical condition (293.89), and catatonia secondary to mania or major depression (these lack specific diagnostic codes).
Some authors have advocated a separate nosology for catatonia.7,8 This argument is based on the provisional nature of a diagnosis of catatonia, since it can be associated with metabolic, toxic, neurologic, or psychiatric conditions while appearing similar in features. In addition, the treatment of catatonia is different from that of other major psychiatric disorders. It typically responds well to lorazepam(Drug information on lorazepam) and related benzodiazepines as well as electroconvulsive therapy (ECT), and it may be precipitated or worsened by antipsychotic medications.
A related difficulty of the DSM-IV nosology is that catatonia due to a general medical condition (293.89) is disallowed for an episode that occurs exclusively during the course of a delirium. The DSM requisite of assessing consciousness/attention and cognition is problematic in the usually mute catatonic patient.
Another nosologic debate is whether neuroleptic malignant syndrome (NMS) and serotonin syndrome are forms of malignant catatonia.9,10 These syndromes share many clinical features with catatonia, and recent reports show autonomic disturbances in catatonia, highlighting the clinical overlap. A systematic review of defined NMS cases showed 15 of 16 with catatonia, and severity ratings of NMS correlated with the number of catatonic signs.11 In addition, lorazepam12,13 and ECT14 may treat both catatonia and NMS. The advent of specific rating scales for NMS should allow for systematic research as to its treatment and clinical similarity with catatonia.15,16
The relationship of catatonia to other motor disorders, particularly Parkinson disease, has also been addressed. Two reports found catatonia could be separately identified by divergent scores on parallel ratings of Parkinson disease and catatonia scales in elderly patients with either schizophrenia17 or depression.18 Of note in the latter study, apomorphine(Drug information on apomorphine) improved symptoms of Parkinson disease without affecting catatonic symptoms.
Diagnosis and rating scales
In routine practice, the diagnosis of catatonia can be difficult. Operational definitions for catatonic phenomena have not been well described. In addition, there is debate in the research literature about the number of signs necessary and sufficient to diagnose catatonia, with a range of 1 to 4 signs.19 In DSM-IV, the number of motor signs required to meet criteria for catatonia varies with the primary diagnosis. For catatonia secondary to a general medical condition, only 1 motor sign is needed; for the other diagnoses, 2 signs are required.
DSM-IV does not define these signs well, lacks guidelines about the severity required, and offers a probably incomplete list of signs (only 12 signs are given in the criteria for catatonic schizophrenia). Our group developed a 23-item rating scale (Bush-Francis Catatonia Rating Scale [BFCRS]) that operationally defines each catatonic sign, rates its severity, and provides a standardized schema for clinical examination. A case is defined by the presence of at least 2 of the first 14 items from this scale as shown in the Table.
Screening items from the Bush-Francis Catatonia Scale
(Presence of at least 2 of these 14 signs defines a case)
|*DSM-IV catatonic signs.|
Reliability of the BFCRS depends on the use of its companion standardized examination procedure.19,20 This protocol allows rapid and systematic examination, which facilitates monitoring treatment response, which may occur within hours or less. This scale has been confirmed as highly reliable and sensitive to clinical change.21,22 Other catatonia rating scales have been published and generally correlate well.21,23,24 Although the BFCRS has proved useful and practical for clinical and research purposes, the comparative clinical use of these scales is not well established.