Malignant (lethal) catatonia consists of catatonia accompanied by excitement, stupor, altered level of consciousness, catalepsy, hyperthermia, and autonomic instability with tachycardia, tachypnea, hypertension, and labile blood pressure. Autonomic dysregulation, fever, rhabdomyolysis, and acute renal failure can be causes of morbidity and mortality. Neuroleptic malignant syndrome (NMS)—which is associated with dopamine antagonists, especially antipsychotics—is considered a form of malignant catatonia and has a mortality rate of 10% to 20%. Signs of NMS include muscle rigidity, fever, diaphoresis, rigor, altered consciousness, mutism, tachycardia, hypertension, leukocytosis, and laboratory evidence of muscle damage. Serotonin syndrome can be difficult to distinguish from malignant catatonia, but it is usually not associated with waxy flexibility and rigidity.
Several specific subtypes of catatonia that may exist anywhere along dimensions of activity and severity also have been described:
Periodic catatonia. In 1908, Kraepelin described a form of periodic catatonia, with rapid shifts from excitement to stupor.4 Later, Gjessing described periodic catatonia in schizophrenia and reported success treating it with high doses of thyroid hormone.4 Today, periodic catatonia refers to the rapid onset of recurrent, brief hypokinetic or hyperkinetic episodes lasting 4 to 10 days and recurring during the course of weeks to years. Patients often are asymptomatic between episodes except for grimacing, stereotypies, and negativism later in the course.13,15 At least some forms of periodic catatonia are familial,4 with autosomal dominant transmission possibly linked to chromosome 15q15.13
A familial form of catatonia has been described that has a poor response to standard therapies (benzodiazepines and electroconvulsive therapy [ECT]), but in view of the high comorbidity of catatonia and bipolar disorder, it is difficult to determine whether this is a separate condition, or a group of patients with bipolar disorder.5
Late (ie, late-onset) catatonia is well described in the Japanese literature.10 Reported primarily in women without a known medical illness or brain disorder, late catatonia begins with prodromal hypochondriacal or depressive symptoms during a stressful situation, followed by unprovoked anxiety and agitation. Some patients develop hallucinations, delusions, and recurrent excitement, along with anxiety and agitation. The next stage involves typical catatonic features (mainly excitement, retardation, negativism, and autonomic disturbance), progressing to stupor, mutism, verbal stereotypies, and negativism, including refusal of food. Most patients have residual symptoms following improvement. A few cases have been noted to remit with ECT, with relapse when treatment was discontinued. Late catatonia has been thought to be associated with late-onset schizophrenia or bipolar disorder, or to be an independent entity.
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