To determine, using a microdialysis technique, the extracellular levels of glutamate and non-transmitter amino acids in the brain of children with severe head injuries. A microdialysis probe was inserted along side the intracranial pressure (ICP) bolt in 9 children (age range 2-14 years) with severe head injuries (Glasgow coma scale<8). Dialysate samples were collected hourly and analysed, using High Performance Liquid Chromatography (HPLC), for glutamate, glutamine and various structural amino acids. Clinical monitoring parameters were also correlated with amino acid concentrations. Mean glutamate concentrations in the dialysate varied from very low (<5 micro M) to very high (>30 micro M). No correlation with outcome at discharge was demonstrated. Structural amino acid levels did not follow the glutamate fluctuations. Low glutamine/glutamate ratio was associated with increased morbidity, while a high ratio was associated with clinical improvement. Glutamate metabolism may have a more significant role in the pathophysiology of paediatric head injury than has already been recognised.

To survey the current monitoring and treatment policies for patients with severe traumatic brain injury (STBI) in Israel, and to compare the management of pediatric and adult intensive care units (ICUs). Questionnaires were sent to the medical directors of all ICUs managing STBI patients. All 21 ICUs responded to the questionnaire. All of the units were within tertiary hospitals. An intracranial pressure (ICP) monitoring device was used in over 75% of the patients in 6 out of7 (86%) of the pediatric intensive care units (PICUs), compared with 11 out of 14 (79%) of the adults ICUs. Mannitol was used in all of the units for documented elevated ICP. Mild hyperventilation (4-4.6 kPa) was applied in 52% of the units. Mild hypothermia was routinely used in 4 out of 7 (57%) and hypertonic solutions (NaCI 3%) in 3 out of 7 (43%) of the PICUs, compared with only 2 out of 14 (14%) and none (0%) of the adults ICUs respectively. PICUs aimed for a lower ICP (< or =15 mm Hg) and cerebral perfusion pressure (> or =50 mm Hg) than adult ICUs (< or =20 mm Hg and > or =60 mmHg respectively). Barbiturates were used only in patients with refractory intracranial hypertension. This survey reveals a relatively high degree of homogeneity in the treatment of STBI patients in Israel. Most patients are treated in accordance with recently published literature. We attribute this uniformity to the fact that all patients are being treated within tertiary care, university-affiliated centers. PICUs are faster at implementing new modalities of treatment and tend to adopt more aggressive treatment strategies.

Thalamic tumors (TTs) account for approximately 1% of all intracranial neoplasms. TTs are seen predominantly in children and young adults. Most childhood neoplasms in this location are of glial lineage, a large proportion being low-grade tumors. The evolution of symptoms before diagnosis is characteristically shorter in children than in adults. Clinical features of TTs reflect the pressure of the mass on the cerebrospinal fluid pathways, the pyramidal tracts, the thalamic nuclei and the optic radiations. In this paper, we review the clinical data of 20 children with TTs seen at our hospital and compare the findings with those in the current literature. An acute presentation is not rare and was encountered in 20% of our patients, although most individuals had a subacute or slow evolution. Symptoms and signs of raised intracranial pressure (65%), motor deficits (40%), and seizures (35%), alone or in combination, were the most frequent manifestations of TTs. Behavioral and mental changes are not uncommon in TTs and were found in 25% of our patients. Involuntary movements (10%) and the classic thalamic syndrome (5%) were quite exceptional. Infants and young children with TTs may present with macrocephaly, psychomotor delay, and failing vision or disorders of ocular movements.