Intracranial aneurysms in sickle-cell anemia: clinical features and pathogenesis.

Intracranial aneurysms are an unusual complication of sickle-cell anemia; only 15 patients have been described in the world literature. An additional 15 patients with sickle-cell anemia and subarachnoid hemorrhage (SAH) from ruptured intracranial aneurysms are presented. There was a high incidence of multiple aneurysms (60%); some of which were in unusual locations. The clinical and pathological features of this series of patients have provided a paradigm for acquired aneurysm formation that may be applicable to other intracranial aneurysms. Thirteen patients underwent craniotomy and clip ligation; the perioperative management of these patients is discussed. Of these 13, eight had a good recovery, three were left with moderate disability, one patient died of surgical complications, and one died of complications related to sickle-cell anemia. Two of the 15 patients died of SAH. The authors propose that endothelial injury from the abnormal adherence of sickle erythrocytes to the endothelium is the initiating event in arterial wall injury. Subsequently, there is fragmentation of the internal elastic lamina and degeneration of the smooth-muscle layer. Hemodynamic stress at these loci of arterial wall damage results in aneurysm formation. This hypothesis also explains other cerebrovascular manifestations of sickle-cell anemia, namely vaso-occlusive disease and hemorrhage without aneurysm formation. Pathological material from this series and data from the literature are presented to support this hypothesis.

Techniques of peripheral nerve repair.

At present, the principles of microsurgical reconstruction of the peripheral nerve incorporate a clear understanding of the pathophysiology of the peripheral nerve, accurate preoperative assessment of the lesion, aggressive early treatment to avoid irreversible atrophy of the end organ, use of nontraumatic microtechniques for optimal alignment of individual fascicular bundles, introduction of a minimum amount of foreign material at the suture line, resection of the scar-producing epineurium, total avoidance of tension at the suture line, and placement of the nerve repair in a well-vascularized soft tissue bed. If tension is eliminated, a minimal amount of suture material is required to repair the nerve ends, because the bundles are maintained in anatomical alignment by a fibrin clot. We have reviewed the various nerve repair methods, stressing that with strict attention to microsurgical technique, the surgeon can hope to maximize reinnervation. Although the importance of all aspects of careful surgical technique cannot be overemphasized, we believe that it is unlikely that improved clinical results will come from further refinements in microsurgical techniques. We are not limited by a working knowledge and understanding of the details of the neurobiology and the neurochemistry of nerve regeneration.

Diffuse idiopathic skeletal hyperostosis causing acute thoracic myelopathy: a case report and discussion.

A case of diffuse idiopathic skeletal hyperostosis presenting as acute thoracic myelopathy is reported. Diffuse idiopathic skeletal hyperostosis has long been regarded as a radiological entity with an innocuous clinical course. The manifestations of this disease are reviewed. There is mounting evidence that it is neither a clinically infrequent nor, as this case report illustrates, an exclusively benign condition.

Transcranial stab wounds: a report of three cases and suggestions for management.

Transcranial stab wounds are uncommon. Three such cases are presented. The severity of the wounds may vary from innocuous to devastating. Skull films are useful in delineating the depth of penetration. The presence of the knife blade in situ may make the computed tomographic scan impossible to perform or difficult to interpret. Cerebral angiography may be indicated if injury to a major cerebral vessel is suspected or if the patient suffers a delayed subarachnoid or intracerebral hemorrhage. Provided that the patient's clinical status indicates a positive prognosis, transcranial stab wounds should be explored surgically. The weapon should be removed in the operating room immediately before or at the time of operation.

Classification and treatment of spontaneous carotid-cavernous sinus fistulas.

An anatomical-angiographic classification for carotid-cavernous sinus fistulas is introduced and a series of 14 patients with spontaneous carotid-cavernous sinus fistulas is reviewed to illustrate the usefulness of such a classification for patient evaluation and treatment. Fistulas are divided into four types: Type A are direct high-flow shunts between the internal carotid artery and the cavernous sinus; Type B are dural shunts between meningeal branches of the internal carotid artery and the cavernous sinus; Type C are dural shunts between meningeal branches of the external carotid artery and the cavernous sinus; and Type D are dural shunts between meningeal branches of both the internal and external carotid arteries and the cavernous sinus. The anatomy, clinical manifestations, angiographic evaluation, indications for therapy, and therapeutic options for spontaneous carotid-cavernous sinus fistulas are discussed.

Inflammatory meningeal masses of unexplained origin. An ultrastructural and immunological study.

Two patients with inflammatory meningeal masses were studied. Lesions in both patients showed varying proportions of meningothelial and inflammatory components. The non-neoplastic nature of the inflammation was confirmed in one case by lymphocyte surface marker study, which showed T and B cells in one to four ratio, and by immunohistochemistry, which revealed polyclonal plasma cells. The abundant histiocytes contained muramidase and often enclosed intact lymphocytes or plasma cells within their cytoplasm, i.e., emperipolesis. Their surfaces bore slender interdigitating pseudopodia, intercellular junctions, and subplasmalemmal linear densities. The derivation of these histiocytes is uncertain: mononuclear phagocytes, meningothelial cells, and multipotential meningeal cells are all possible progenitors. A comparison with eleven similar reported cases reveals a tendency for inflammatory meningeal masses to occur in the young, as well as a predilection for posterior fossa involvement. They resemble the extranodal lesions of sinus histiocytosis with massive lymphadenopathy, as well as plasma cell granulomas or inflammatory pseudotumors of lung and other tissues. However, it is possible that these lesions represent a variant of meningioma in which an unusual immunological response has been evoked.