The term phrenitis was employed in ancient Greece by Hippocrates

Hippocrates

Hippocrates of Cos or Hippokrates of Kos was an ancient Greek physician of the Age of Pericles , and is considered one of the most outstanding figures in the history of medicine...

 and his followers. It refers to acute inflammation of mind and body, not in a theoretical but in a descriptive sense. Its presumed seat was never anatomically or conceptually well determined. The diagnosis was used during the Middle Ages

Middle Ages

The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...

: a mental confusion or continuous delirium

Delirium

Delirium or acute confusional state is a common and severe neuropsychiatric syndrome with core features of acute onset and fluctuating course, attentional deficits and generalized severe disorganization of behavior...

 with fever

Fever

Fever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...

.

Phrenitis means an inflammation

Inflammation

Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...

 of the brain, or of the meninges

Meninges

The meninges is the system of membranes which envelopes the central nervous system. The meninges consist of three layers: the dura mater, the arachnoid mater, and the pia mater. The primary function of the meninges and of the cerebrospinal fluid is to protect the central nervous system.-Dura...

 of the brain, attended with acute fever and delirium. Symptoms vary widely in severity, from short-lived, relatively slight effects of headache, drowsiness, and fever to paralysis

Paralysis

Paralysis is loss of muscle function for one or more muscles. Paralysis can be accompanied by a loss of feeling in the affected area if there is sensory damage as well as motor. A study conducted by the Christopher & Dana Reeve Foundation, suggests that about 1 in 50 people have been diagnosed...

, coma

Coma

In medicine, a coma is a state of unconsciousness, lasting more than 6 hours in which a person cannot be awakened, fails to respond normally to painful stimuli, light or sound, lacks a normal sleep-wake cycle and does not initiate voluntary actions. A person in a state of coma is described as...

, and death

Death

Death is the permanent termination of the biological functions that sustain a living organism. Phenomena which commonly bring about death include old age, predation, malnutrition, disease, and accidents or trauma resulting in terminal injury....

.

The ancient phrenitis concept was used until the 19th century. After that time the concept was replaced by the word delirium. By their epigonic character the detailed descriptions of phrenitis by Gerard van Swieten

Gerard van Swieten

Gerard van Swieten was a Dutch-Austrian physician.Van Swieten was born in Leiden. He was a pupil of Hermann Boerhaave and became in 1745 the personal physician of the Austrian Empress Maria Theresa. In this position he implemented a transformation of the Austrian health service and medical...

 mark only the end of an uncritical use of the term. The epoch-making work of Morgagni

Giovanni Battista Morgagni

Giovanni Battista Morgagni was an Italian anatomist, celebrated as the father of modern anatomical pathology.-Education:...

, based on clinical-anatomical observations, provides a definitive insight into the location of the condition and into many pathologic features. Pinel

Philippe Pinel

Philippe Pinel was a French physician who was instrumental in the development of a more humane psychological approach to the custody and care of psychiatric patients, referred to today as moral therapy...

 is the last author who mentions phrenitis in a classification of diseases.

Phrenitis is no longer in scientific use. Nowadays meningitis

Meningitis

Meningitis is inflammation of the protective membranes covering the brain and spinal cord, known collectively as the meninges. The inflammation may be caused by infection with viruses, bacteria, or other microorganisms, and less commonly by certain drugs...

 or encephalitis

Encephalitis

Encephalitis is an acute inflammation of the brain. Encephalitis with meningitis is known as meningoencephalitis. Symptoms include headache, fever, confusion, drowsiness, and fatigue...

are diagnosed. Relating to phrenitis: suffering from frenzy; delirious; mad; frantic; frenetic.