Leukoencephalopathy after CNS prophylaxis for acute lymphoblastic leukaemia

Generalized spike-wave discharges with focal onset in a patient with head trauma and diffuse cerebral lesions: a case report with EEG and cranial MRI findings

The role of cerebral lesions associated with absence seizures, outside the frontal lobe, has not been demonstrated by both electroencephalography and neuroimaging techniques until now, to our knowledge. We present a case with absence seizures and EEGs with generalized 3 Hz spike-wave patterns that were preceded by a burst of spike-waves on the right parieto-occipital region. The patient had a history of head trauma, and cranial MRI revealed lesions that might be responsible for the seizures. The patient's lateralized and localized EEG findings were probably a representation of secondary bilateral synchrony (SBS). The mechanism of SBS is considerably more complex than a simple triggering of generalized spike-wave complexes from a single cortical focus.

Hippocampal brain amines in methotrexate-induced learning and memory deficit

Intrathecal methotrexate in children with leukemia is known to cause seizures, dementia, leukoencephalopathy, and cognitive dysfunction after long-term treatment. To investigate the cognitive dysfunction, male Wistar rats were given multiple intracerebroventricular injections of methotrexate. Its effect on behaviour was tested in the two-compartment conditioned avoidance task and dark-bright arena test. Levels of brain amines in the hippocampal region of the brain were estimated by HPLC. The qualitative and quantitative histopathological changes in the different regions of the hippocampus were studied by cresyl violet staining. Multiple injections (1 or 2 mg/kg) produced convulsions and learning and memory impairment but did not induce anxiolytic activity. They also reduced concentrations of all three brain amines (norepinephrine, dopamine, and serotonin) and the serotonin metabolite 5-hydroxyindoleacetic acid. The CA4 region of the hippocampus was severely affected by intraventricular methotrexate. Disruption of brain monoamines has been proposed as a cause of brain dysfunction from this chemotherapy, and that disruption may in turn involve cytotoxic effects of methotrexate on brain tissue. The outcomes of this study may have therapeutic implications in the management of cancer conditions, particularly in childhood lymphoblastic leukemia.