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At a glance

It is a very rare and potentially lethal neurologic disorder characterized by failure to thrive, severe emaciation, amnesia, intense sleepiness, unusual eye position, and sometimes blindness. It is normally seen in infancy or early childhood but some cases in older children and adults have been reported. Diencephalic Syndrome usually is caused by a brain tumor such as a low-grade glioma or astrocytoma. Onset age of presentation usually is the young infant or child between the ages of 18 months and 3 years. However, it also can develop during adolescence and even adulthood.


Russell Diencephalic Cachexia Syndrome; Russell Syndrome; Diencephalic Syndrome of Childhood; Diencephalic Syndrome of Emaciation; Paramedian Diencephalic Syndrome.


This medical condition was first described by A. Russell in 1951.


The exact incidence and prevalence in the general population remains unknown. It is a very rare disorder that affects males and females equally. It has been reported worldwide. Childhood brain tumors arise in 2.5 to 3.5:100,000 children per year.

Genetic inheritance

This is not a genetic medical condition. Diencephalic Syndrome is caused by a brain tumor that is most commonly located in the hypothalamus or the optic chiasm. The two most frequent tumoral masses are glioma and astrocytoma.


Results from the development of a brain tumor in the hypothalamic or optic chiasm regions, often a low-grade glioma or astrocytoma. The tumor may invade the anterior portion of the third ventricle and affect the optic nerve or optic chiasm. The presence of this expanding intracerebral mass leads to raised intracranial pressure (ICP). The cause of the weight loss is unknown, but excessive growth hormone secretion, activation of proteins produced by the pituitary gland that break down fat, or secretion of a fat mobilizing compound have been implicated. There is no known genetic predisposition for Diencephalic Syndrome.

Clinical aspects

It is a very rare disorder that usually affects infants and young children. It is characterized by a failure to thrive, emaciation, and normal linear growth. A history of normal development and weight gain is normally followed by either a prolonged period of failure to gain weight or weight loss. The individual may have anorexia or bulimia. Over time, loss of body fat occurs and leads to an emaciated appearance. The child may have a relatively large head compared with body weight. Overall development is often slowed, but results of neurologic testing are normal. The eyes are often affected, and the infant or child may present a strabismus, nystagmus, papilledema, or blindness. The child may be unusually sleepy. The patient usually behaves in a normal, alert, happy manner that is not in keeping with the physical appearance. Growth hormone plasma ...

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