The clinical condition denoted<unk>  was first described in 1838; however, since that time, a number of different, some contradictory, definitions have emerged.<unk>  has been described as a loss of drive, expression, behavior and speech output, with slowing and prolonged speech latency, and reduction of spontaneous thought content and initiative. The clinical features most commonly associated with<unk>  are: * Difficulty in initiating and sustaining purposeful movements * Lack of spontaneous movement * Reduced spontaneous speech * Increased response-time to queries * Passivity * Reduced emotional responsiveness and spontaneity * Reduced social interactions * Reduced interest in usual pastimes Especially in patients with progressive dementia, it may affect feeding. Patients may continue to chew or hold food in their mouths for hours without swallowing it. The behavior may be most evident after these patients have eaten part of their meals and no longer have strong appetites. Differentiation from other disorders Both neurologists and psychiatrists recognize<unk>  to be a distinct clinical entity, but its status as a syndrome is unclear. Although<unk>  has been known to clinicians since 1838, it has been subjected to different interpretations – from 'a pure lack of will', in the absence of motor paralysis to, more recently, being considered 'a reduction in action emotion and cognition'. As a result of the changing definition of<unk> , there is currently a debate on whether or not<unk>  is a sign or a symptom of another disease, or its own disease that seems to appear in the presence of other more well-researched diseases, such as Alzheimer's disease. A 2002 survey of two movement disorder experts, two neuropsychiatrists, and two rehabilitation experts, did not seem to shed any light on the matter of differentiating<unk>  from other DDMs. The experts used the terms "apathy" and<unk> " interchangeably and debated whether or not<unk>  was a discrete entity, or just a hazy gray area on a spectrum of more defined disorders. Four of the experts said<unk>  was a sign and a symptom, and the group was split on whether or not it was a syndrome. Another survey, which consisted of true and false questions about what<unk>  is distinct from, whether it is a sign, symptom, or syndrome, where lesions are present in cases of<unk> , what diseases are commonly associated with<unk> , and what current treatments are used for<unk> , was sent to 15 neurologists and 10 psychiatrists. Most experts agreed that<unk>  is clinically distinct from depression, akinetic mutism, and alexithymia. However, only 32% believed<unk>  was different from apathy, while 44% said they were not different, and 24% were unsure. Yet again, there was disagreement about whether or not<unk>  is a sign, symptom, or syndrome. The study of motivation has been mostly about how stimuli come to acquire significance for animals. Only recently has the study of motivational processes been extended to integrate biological drives and emotional states in the explanation of purposeful behavior in human beings. Considering the number of disorders attributed to a lack of will and motivation, it is essential that<unk>  and apathy be defined more precisely to avoid confusion.
Abulia
Iatrosophia
Equinovalgus
Pinguecula
Acalvaria
Epiblepharon
Liber pantegni
Prospero