Astrocytic Tumors

Astrocytic tumors constitute the largest group of intracranial tumors in both adults and children. Their locations, gross and histologic features, biologic behavior, and genetic alterations vary greatly. The WHO distinguishes four grades of astrocytic tumors based on their histologic characteristics (Table 11.5). Astrocytic Tumors (Grades 2, 3, and 4) Diffuse astrocytoma grade 2, anaplastic astrocytoma grade 3, and glioblastoma grade 4 constitute the largest group of primary intracranial tumors...

Ischemic Stroke Cerebral Infarction

The brain requires a constant and adequate blood flow to supply oxygen and glucose essential for its high energy metabolism. A constant blood flow is assured by an autoregulatory mechanism of arteries and arterioles they constrict in response to rising systemic blood pressure and dilate in response to falling systemic blood pressure. This mechanism operates while the arterial pressure remains between 50 and 160 mm Hg. One- Atherosclerosis of cerebral arteries. A. Severe atheromatosis of basal...

Cerebral Parenchymal Injuries

Parenchymal injuries are focal, diffuse, or both. Focal injuries contusion and laceration generally result from contact head injuries. Diffuse injuries result from acceleration of the head. Contusions are bruises in the crest of the convolutions, characteristically, in the frontal and temporal Acute contusion. A. Schematic drawing shows the sites of predilection of the contusions. B. Extensive subarachnoid hemorrhage and hemorrhagic necrosis of the frontoorbital and tem-poromesial cortex. Acute...

Intracranial Hemorrhages

Intracranial hemorrhages may occur in the epidural, subdural, and subarachnoid compartments and within the brain parenchyma. Epidural hematoma EDH occurs in 2 of severe head injuries. An epidural hematoma forms between the inner table of the calvarium and the dura, usually in the frontotemporal region Fig. 12.1 . It is commonly an arterial bleed that results from tearing of meningeal arteries, often of the middle meningeal artery, by a linear fracture across its cranial groove. In children, it...

Spinal and Spinal Cord Defects

Vertebral Defects

Dysraphic disorders of the spine and spinal cord comprise a broad spectrum of malformations, ranging from total absence of the cord to asymptomatic bony defects and cord anomalies. Familial occurrences are common. The clinical manifestations vary from mild motor and sensory deficits to paraplegia with severe sensory impairment and loss of sphincter control. Amyelia, total absence of the spinal cord occurs with anencephaly see Fig. 13.2 . The cord is replaced with a mixture of fibrous tissue,...