Studies on small numbers of individuals with the disease have found that the standard chemotherapy regimens used for the initial induction treatments of AML, acute lymphoblastic leukemia, and high-grade lymphoma give complete remission rates of 77%, 93%, and 80%, respectively, in childhood PBDN and 47%, 77%, and 53%, respectively, in adult PBDN. However, these remissions were short-lived: post-treatment mean times to relapse or death were 12 months for children and 6.8 months for adults. Given these poor remission and survival rates, other treatments have been added to the initial treatment regimens. Studies have shown that the addition of intrathecally administered drugs (administered directly into the spinal canal) as prophylaxis prolongs the period of CNS-free disease and increases overall survival. Hematopoietic stem cell transplantation following initial chemotherapy-induced remission also prolongs these remissions and, it is suggested, offers potential for curing the disease. (A graft-versus-leukemia effect may have contributed to the benefits seen after transplantation.) Studies have not yet determined whether allogenic (i.e. taken from others) or autologous (i.e. taken from self) stem cells achieve better results, although one retrospective study in Japan found that autologous stem cells gave significantly better overall and progression-free survival rates.
Opisthotonus or opisthotonos (from Ancient Greek: ὄπισθεν, romanized: opisthen, lit. behind and τόνος, tonos, tension) is a state of severe hyperextension and spasticity in which an individuals head, neck and spinal column enter into a complete "bridging" or "arching" position.This extreme arched pose is an extrapyramidal effect and is caused by spasm of the axial muscles along the spinal column. It has been shown to occur naturally in birds, snakes suffering from advanced boid inclusion body disease, and placental mammals, among existing animals; it is observed in some articulated dinosaur fossils. Causes
Opisthotonus is a symptom of some cases of severe cerebral palsy and traumatic brain injury or as a result of the severe muscular spasms associated with tetanus. It can be a feature of severe acute hydrocephalus, poisoning, and drowning. Infants
Opisthotonus is more pronounced in infants. Opisthotonus in the neonate may be a symptom of meningitis, tetanus, severe kernicterus, or the rare maple syrup urine disease. This marked extensor tone can cause infants to "rear backwards" and stiffen out as the mother or nurse attempts to hold or feed them. Individuals with opisthotonus are quite challenging to position, especially in wheelchairs and car seats.Opisthotonus can be triggered by any attempt at movement, such as smiling, feeding, speech, or by involuntary movement, such as seizures. A similar tonic posturing may be seen in Sandifer syndrome. Poisoning
Opisthotonus can sometimes be seen in lithium intoxication.