Diencephalic Syndrome

Very rare neurologic disorder characterized by failure to thrive, 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 even adults have been reported. Diencephalic syndrome usually is caused by a brain tumor such as a low-grade glioma or astrocytoma.

Russell Diencephalic Cachexia Syndrome; Russell Syndrome

Very rare disorder that affects males and females equally. 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. The syndrome occurs worldwide. Childhood brain tumors arise in 2.5-3.5:100,000 children per year.

Results from the development of a brain tumor in the hypothalamic region, 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. 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.

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 level is usually higher than normal.

Presence of emaciation must be assessed preoperatively for electrolytes and glucose imbalances. Intraoperative thermoregulatory heat loss must be carefully managed. Presence of elevated intracranial pressure must be ruled out. If present, proper anesthesia management for raised intracranial pressure must be ensured. The anesthetic considerations for brain tumour are not specific to this syndrome and are reviewed in the textbook entitled Pediatric Anesthesia: Principles and Practice by the same author.

Tolosa-Hunt Syndrome: Rare disorder that includes headaches, fever, and vision impairment. There may be eye muscle paralysis, swelling and protrusion of the eye, drooping eyelid, and diminished vision.