Thirteen patients harboring large petroclival meningiomas are reported. The evolution of the petrosal approach is discussed, and modifications for improvement in surgical technique are described. There was no mortality in this series, and total removal was achieved in all but two patients. Morbidity included cranial nerve deficit, pulmonary embolism, and hemiparesis.

An anti-siphoning valve for use in hydrocephalic shunt systems is described. The addition of this valve to the system effectively reduces the hazard of negative intraventricular pressure when the patient is sitting or standing. The formation of post-shunt subdural hematomas was prevented by temporary postoperative occlusion of the shunt using a percutaneously reversible occlusion valve, which is also described. KEY WORDShydrocephalie shunts hypotension subdural hematoma 9 reversible occlusion valve siphon effect ventricular anti-siphon valve 1.

Eighteen cases are presented in which magnetic resonance (MR) imaging demonstrated two types of lesions in patients with cervical spondylotic myelopathy. In the first type, localized spinal cord changes at the level of compression, consistent with myelomalacia, were revealed best with T2-weighted images as high-intensity spinal cord signals. In the second type, lesions consistent with either cystic necrosis or secondary syrinx were noted locally, and/or extending longitudinally up, and/or down inside the spinal cord. These latter lesions were best revealed as low-intensity signals on T1-weighted MR images and as a signal-void sign (moving fluid) on proton-density or T2-weighted MR images. It is suggested that segmental lesions at the level of the spondylotic bar represent early proton changes from pressure in and around the same zones that evolve into gray-matter enhancement regions shown as "snake-eyes" on delayed computerized tomography (CT) after myelography. The longitudinal lesions are thought to be the same pencil-shaped zones of cystic necrosis evolving into a secondary syrinx in the late stages (and usually found in the anterior portion of the dorsal columns during delayed CT after myelography). As spinal MR imaging continues to improve, these lesions will be demonstrated more clearly within the cord substance.

Des chercheurs ont Btudi6 les cas de harchlement sexuel en milieu de travail et dans les universitbs. En collaboration avec des experts judiciaires, ils ont conceptualist5 le harcblement sexuel et en ont fait une question de droits de la personne. Notre recherche, fond& sur un sondage effectu6 en 1992 auprhs de 1 990 femmes canadiennes, rbvhle que le harchlement sexuel se produit aussi dans les l i e n publics. Nous prbsentons des donnees inedites sur le sujet en examinant le type, la frt5quence et la Davit6 du harchlement, les caracteristiques des femmes le plus susceptibles d'&tre harcelees, les implications pouvant servir B bltir une theorie sur le harchlement dans les l i e u publics, les reactions des femmes B l't5gard du harchlement ainsi que ses consequences sur les plans Bmotionnel et psychologique. 403 280 555 360 354 420 602 555 343 296 579 143 777 163 64 250 1. Adjusted percentages are based on logit models fit to the data (see text). 2. Numbers ofcases sum to different totals due to deletion of missing values; there are also small dflerences in counts due to variations in the pattern of missing data for the different types of harassment. The counts given are for the first type of harassment, 'stared.' 3. p-values for differences among percentages are from chisquare tests of independence; pvalues for diWrences among adjusted percentages are from Wald te~rs ofthe coefficients in the logit models.