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✓ Although posttraumatic syringomyelia is a well-established clinicopathological entity, there is a paucity of information on the ultrastructural features of this condition. This study documents the light and electron microscopic features of posttraumatic syringes obtained from two patients who underwent surgical cordectomy. The syringes were lined largely by cell processes of astrocytes. Small regions near the caudal end were lined by flattened ependymal cells that lacked surface specializations. These were thought to represent remnants of the central canal ependyma. The ultrastructural appearance of the syrinx was similar to that of the communicating syringomyelia as well as the periventricular changes that accompany hydrocephalus. The authors conclude that the changes represent the nonspecific sequelae of a distensile force within the syrinx cavity.

✓ It has recently been reported that pretreatment with a single dose of dexamethasone (0.1 mg/kg) 24 hours before hypoxia in 7-day-old rat pups is protective against an hypoxic-ischemic insult (unilateral carotid artery occlusion followed by 3 hours of hypoxia in 8% O₂). The authors now examine whether pretreatment 6 hours before insult is equally effective and compare other agents potentially suitable for prophylaxis in neonatal hypoxia-ischemia, including the calcium antagonists flunarizine (30 mg/kg pretreatment), nimodipine (0.5 mg/kg pretreatment), and the 21-aminosteroid U-74389F (10 mg/kg pre- and posttreatment). For each active agent, there was also a vehicle-treated control group.

Comparison of the mean area of ipsilateral infarction on brain coronal sections showed that there was no statistically significant difference between the various control groups (mean area of infarction 66% ± 4%). Pretreatment with dexamethasone 6 hours prior to hypoxia offered complete protection with no infarction. A beneficial effect was seen following pretreatment with flunarizine (mean area of infarction 33.6% ± 7.8%), although this degree of damage was still significantly different from that seen with dexamethasone pretreatment. Pretreatment with nimodipine or U-74389F offered no protection (mean area of infarction 77.5% ± 4% and 59% ± 10%, respectively). Unlike findings in adult animals and clinical studies, the current studies show that dexamethasone may have a role in the treatment of neonatal hypoxia-ischemia and deserves reappraisal.

✓ The metabolic changes in neonatal hydrocephalus that lead to permanent brain injury are not clearly defined, nor is the extent to which these changes can be prevented by a cerebrospinal fluid shunt. To clarify these processes, cerebral glucose utilization was examined using [¹⁴C]2-deoxyglucose autoradiography in 1-month-old kittens, kaolin-induced hydrocephalic littermates, and hydrocephalic kittens in which a ventriculoperitoneal shunt had been inserted 10 days after kaolin injection. The hydrocephalic kittens showed thinning of the cerebral mantle and an anterior-to-posterior gradient of enlargement of the ventricular system, with a ventricle:brain ratio of 24% for the frontal and 35% for the occipital horns compared with control (< 0.5%) and shunted (< 5%) animals. White matter in hydrocephalic animals was edematous. Myelination was delayed in the periventricular region and in the cores of the cerebral gyri.

Glucose utilization in hydrocephalic and shunted animals was unchanged from control animals in all gray-matter regions examined. However, in hydrocephalic animals, the frontal white matter exhibited a significant increase in glucose utilization (25 µmol • 100 gm⁻¹• min⁻¹) in the cores of gyri compared with normal surrounding white-matter values (14.8 µmol • 100 gm⁻¹• min⁻¹). Very low values (mean 4 µmol • 100 gm⁻¹• min⁻¹) were found in areas corresponding to severe white-matter edema, and these areas were surrounded by a halo of increased activity (24 µmol • 100 gm⁻¹• min⁻¹). In contrast, cytochrome oxidase activity in white matter was homogeneous. Shunting resulted in restoration of the cerebral mantle thickness, a return to normal levels of glucose utilization in the white matter, and an improvement in myelination.

It is suggested that the areas of increased glucose utilization seen in the white matter represent anaerobic glycolysis which, if untreated, progresses to infarction. The pattern of this increased glucose utilization matches that of expected myelination and, during this period of high energy demand, white matter may be susceptible to the hypoperfusion associated with hydrocephalus.

✓Shunt failure is commonly associated with infection or mechanical obstruction of the shunt system. The presence of eosinophilia in the cerebrospinal fluid (CSF) has been associated with CSF shunt failure and may be related to both latex and shunt allergies. The authors describe the case of a child with a latex allergy who presented with 10 episodes of shunt failure over a period of 93 months. Cerebrospinal fluid sampling demonstrated persistent eosinophilia (3–36%) and negative cultures. Pathological examination of the ventricular catheter on 3 occasions demonstrated mechanical obstruction by inflammatory debris consisting largely of eosinophils and multinucleated giant cells. On the suspicion that the child might have some uncharacterized allergy to the shunt hardware, shunt replacement was performed using an “extracted” shunt system. The child has remained free of shunt malfunction for > 2 years since the last surgery. Immune responses to unpolymerized silicone are discussed.

1950年,德怀特·帕金森是第一个合格neurosurgeon to arrive in Winnipeg, Manitoba. He played a monumental role in developing one of the earliest neurosurgical training programs in Western Canada. Parkinson was a pioneering neurosurgeon who served as the first president of the Canadian Neurosurgical Society in 1965. He was the epitome of the skull base neurosurgeon, which was not recognized as a distinct discipline at that time. He contributed to its development through detailed neuroanatomical study of the lateral sellar compartment (housing the parasellar venous plexus, a term he emphasized as more accurate than “cavernous sinus”). Parkinson also made seminal contributions to the management of cerebrovascular disease and offered new insights on cerebral concussion. Parkinson’s dedication to clinical excellence and education laid a cornerstone for the development of neurosurgery and the neurosciences in Manitoba, making him a key figure in Canadian neurosurgery. Using published materials, online resources, hospital archives, and personal interviews, the authors conducted a systematic review of Parkinson’s formative years, his development of the Section of Neurosurgery at the University of Manitoba, his achievements, and his legacy. This updated biography captures the exploits of this remarkable, and at times strictly disciplinarian, neurosurgeon-anatomist.