Similarly, impulsivity, mannerisms, excitement, and combativeness are signs of catatonia that may be associated with hyperactive delirium. Among the most common signs are immobility, withdrawal, posturing, mutism, and negativism, which could be identified in hypoactive delirium. 9,10Ĭatatonia is a well-characterized but often unrecognized syndrome with motor and behavioral signs. Sporadic reports suggest that signs of catatonia can be seen in delirium, but there has been no attempt to examine this question systematically using defined criteria for catatonia. Delirium or catatonia? Our hypothesis is that hypoactive (or hyperactive) forms of delirium may also be conceptualized as motor signs of catatonia. The presence of at least 2 items from this list identified the hypoactive subtype. A reduced awareness of one’s surroundings.3 The resulting hypoactive motor factor included 7 clinical signs: The most comprehensive recent synthesis of strategies for motor subtyping of delirium used a factor analysis to define the motor subtypes. 7 A recent review supports the concept that motor subtypes in delirium may differ and that subtyping may prove useful for clinical and research goals. However, an earlier smaller study with 24 patients found no difference in the efficacy of haloperidol and chlorpromazine for delirium according to motor subtype. Patients with the hypoactive form of delirium showed a significantly reduced response rate (48%) compared with those who had the hyperactive subtype (83%). 6 The study used rating scales to monitor severity of delirium after treatment with olanzapine for 7 days.

This view is supported by an open prospective study of delirium treatment in 79 patients with cancer. In addition to etiology and clinical features, the motor subtype of delirium may affect treatment response. Patients with the hyperactive subtype of delirium showed an opposite pattern, with initially low levels that increased with recovery. 5 Levels of 6-SMT were markedly elevated in patients with hypoactive delirium, and were reduced during recovery. 4 A more recent study examined urinary excretion of 6-sulfatoxymelatonin (6-SMT, a metabolite of melatonin) in patients with hypoactive delirium. For example, in a study of delirium tremens, elevated cerebrospinal fluid concentrations of homovanillic acid (HVA, a metabolite of dopamine) correlated with the degree of agitation. Other studies of delirium have shown evidence for neurochemical differences according to motor subtype. Some studies have found that these subtypes predict etiology, clinical course, morbidity, presence of psychosis, and other factors. These studies show various rates of the hypoactive, mixed, and hyperactive forms using differing criteria and definitions.

3 Numerous studies over the past 20 years have attempted to define these motor subtypes of delirium. Our findings may have treatment implications that are yet to be determined.Įtiology, features, and subtypes Studies of noncognitive features of delirium, such as motor activity, have led to the conceptualization of hypoactive, hyperactive, and mixed subtypes based on the salient activity pattern. These cases support the concept of a catatonic subtype of delirium. Here we discuss the various subtypes (hypoactive, hyperactive, and mixed) of Delirium and review the cases of 16 patients who met criteria for concurrent delirium and catatonia. Lipowski 2 characterized delirium as a disorder of attention, wakefulness, cognition, and motor behavior. 1 DSM-IV criteria for delirium require a disturbance of consciousness or attention and a change in cognition that develops acutely and tends to fluctuate in severity. The DSM-IV model views delirium as an acute reversible neuropsychiatric syndrome caused by general medical conditions and/or exogenous substances. Various terms have been used for delirium, such as acute brain disorder, metabolic encephalopathy, organic brain syndrome, and ICU psychosis. It is a brain disturbance manifested by a syndrome of diverse neuropsychiatric symptoms. Delirium has been recognized and described since antiquity.

Catalepsy vs cataplexy