Pituitary apoplexy after aortic abdominal aneurysm surgery: a case report.

Pituitary apoplexy (PA) occurring after surgery is a rare but life-threatening acute clinical situation following extensive haemorrhage or necrosis within a pituitary adenoma. Pituitary apoplexy has been reported to occur spontaneously in the majority of cases or in association with various inducing factors. One of the pathophysiological mechanism that has been postulated is the fall of arterial blood pressure inducing ischaemia followed by infarction of the pituitary gland. We report a case of pituitary apoplexy following aortic abdominal surgery. To our knowledge, this has not been previously reported. A 73-year old man complained of headache and diplopia. At clinical examination, he presented a right oculomotor nerve palsy. Magnetic resonance imaging (MRI) showed a haemorrhagic sellar mass. In our case, intraoperative hypotension could have been the precipitating factor. Diagnostic and therapeutic measures are discussed.

[A surgical approach to Holmes' tremor associated with high-frequency synchronous bursts]. / Approche chirurgicale d'un tremblement de Holmes associé à un tremblement synchrone de haute fréquence.

INTRODUCTION: The effectiveness of thalamic stimulation is now clearly demonstrated for essential tremor, but remains to be demonstrated for other types of tremor. OBSERVATION: A young woman presented Holmes' tremor resulting from a pontine tegmental hemorrhage related to an arteriovenous malformation. A surgical approach was considered when major functional impairment persisted at 2-year follow-up despite drug therapy. The patient underwent unilateral thalamic deep brain stimulation (Vim); major improvement persisted at eighteen months follow-up. CONCLUSION: This observation is in line with previous reports suggesting that thalamic surgery can be one of the best options for treating medically intractable Holmes' tremor. The mechanism underlying the tremor, implying dentate-rubro-thalamic pathways is discussed. Moreover, the patient exhibited short periods of 16Hz tremor when her arms were maintained outstretched. Thalamic stimulation also appears to be effective for these high-frequency synchronous cerebellar bursts.

[Isolated idiopathic amyloid tumor of the sacrum. An important differential diagnosis]. / Amyloïdome solitaire idiopathique du sacrum. Un diagnostic différentiel important.

Primary amyloidosis may present as a pseudotumoral mass. Often associated with myeloma or paraproteinemia, it may also be isolated, without preexisting or associated disease. Isolated pseudotumoral bone involvement is rare and especially in the spine. Differential diagnosis is very important, because the prognosis of primary amyloidoma is excellent after surgical removal.

Unusual occurrence of a pseudo-aneurysm of the middle cerebral artery in a patient with fibromuscular dysplasia.

Our patient is the first reported case of pseudo-aneurysm due to the rupture of an intracranial artery in the context of fibromuscular dysplasia (FMD). As we assume that our case is probably not unique, we conclude that this diagnosis may be sometimes overlooked for lack of confirmation either by surgery or autopsy. The retrospective study of the arteriograms suggests some clues that should be taken into account to foresee the existence of an intracranial pseudo-aneurysm in order to avoid unexpected peroperative difficulties: 1.) the rapid growth of the lesion within a few weeks and 2.) the unusual location of the aneurysmal neck at some distance from a arterial bifurcation.

[Frontal sinusitis, palpebral abscess and exophthalmia due to osteoma]. / Sinusite frontale, abcès palpébral et exophtalmie sur ostéome.

Although osteomas of the paranasal sinuses are slowly growing bony benign neoplasms, they can cause very important orbital or neurological complications. A 58 year old man's osteoma with sinusitis, abscess and proptosis is reported. A review of the literature is presented and the importance of CT scanner, to appraise the enlargement of the tumor and so to select the best surgical approach, is defined.

Lesions in the cat prepositus complex: effects on the vestibulo-ocular reflex and saccades.

The effects of bilateral electrolytic lesions within and around the prepositus hypoglossi (p.h.) nucleus on horizontal saccades in the dark and on the horizontal sinusoidal vestibulo-ocular reflex (v.o.r.) in the dark were studied. After p.h. lesion, including its rostral part between P 7 and P 8, the v.o.r. showed a phase lead as much as about 90 deg at 0.10 Hz. A significant gain reduction paralleled that phase lead at lower frequencies. A large post-saccadic drift was also observed, the time constant of which ranged from 0.3 to 0.6 s. After p.h. lesion extending from P 8 to P 11 (but sparing the rostral part of the p.h.), no significant gain or phase lead change was observed. Post-saccadic drift was either missing or weak. A bilateral medial vestibular nucleus (m.v.n.) lesion from P 7 to P 11 produced a marked gain decrease, paralleled by a marked phase advance. A post-saccadic drift was observed (tau = 0.6 s). A surgical mid-line lesion from P 7 to P 11 (depth: about 2 mm) was followed by no remarkable change in the gain and in the phase of the v.o.r. No post-saccadic drift was observed after such lesion. It was concluded that (i) both the horizontal v.o.r. integration processing, and the horizontal saccadic integration processing were destroyed when an electrolytic lesion was made 'in the region of' the rostral part of the p.h. nucleus, and that (ii) the posterior four-fifths of the p.h. was the location of neither the horizontal v.o.r. integrator nor the horizontal saccadic integrator.

Vestibulo-ocular reflex, optokinetic response and their interactions in the cerebellectomized cat.

The effects of total ablation of the cerebellum on eye movements were studied in alert adult cats. The normal cat could easily hold a steady eye position after a saccadic movement in the dark. The cerebellectomized animal could not: after a saccade the eye position shifted towards a more central position. Vision reduced this 'post-saccadic drift'. The sinusoidal vestibulo-ocular reflex (v.o.r.) was strongly affected by total cerebellectomy. In darkness the v.o.r. gain remained stable at high frequencies (0.5 and 1 Hz) but decreased markedly at lower frequencies to as low as 0.18 at 0.05 Hz. A phase advance (up to 65 degrees at 0.05 Hz) paralleled this gain depression. Velocity characteristics of optokinetic nystagmus (o.k.n.) and optokinetic after-nystagmus (o.k.a.n.) induced by constant-velocity full-field rotation of 60 deg/s amplitude and 60 s duration were studied. The features of o.k.n. (initial velocity, maximal velocity and time constant) were only mildly affected by cerebellectomy. On cessation of visual stimulation when the animal was plunged into darkness, the velocity of the eyes decreased progressively (o.k.a.n.). The time constant of o.k.a.n. was 12.5 s in the normal cat and 4.2 s in the cerebellectomized cat. Furthermore cerebellectomy abolished the secondary o.k.a.n. Optokinetic response was also tested by a set of sinusoidal (0.05-1 Hz; 3-20 degrees) full-field stimuli. The o.k.n. was not abolished but dramatically decreased, especially at higher frequencies. No response could be detected above 0.15 Hz. Visual suppression of inappropriate vestibulo-ocular reflex was still possible but was mildly impaired after cerebellectomy. Visual suppression could only be detected with stimuli below 0.25 Hz. Visual suppression of caloric nystagmus was studied in the normal cat. A clear dependence of the effectiveness of visual suppression on the velocity of the nystagmus was demonstrated. In the cerebellectomized cat, the visual suppression of caloric nystagmus was lost when tested on nystagmus velocities above 20 deg/s but remained when tested on nystagmus velocities below 20 deg/s. The relationship between cerebellectomy and the loss of visual suppression of caloric nystagmus was found to be at least partially indirect: cerebellectomy increased the velocity of caloric nystagmus, and visual suppression was usually less effective at higher velocities.

[Quantitative study of the peripheral nerve in semi-thin section by the Nomarski interference contrast technic]. / Etude quantitative du nerf pêriphêrique sur coupes semi-fines par la technique du contraste interfêrentiel de Nomarski

The Normarski interference-contrast microscope is well suited to observations of transverse thick sections of epon-embedded peripheral nerves. The quantitative study of myelinated fibers is possible on photomicrographs with a final magnification of X 500. The induced distorsion is very small as compared with the results obtained by conventional bright field and positive phase contrast optics. The comparative study of the same field with the three devices allows a better interpretation of marginal pictures.

Pharmacological study of cefazolin during intermittent and continuous infusion: a crossover investigation in humans.

Levels of cefazolin were determined in plasma, urine, bile, and cerebrospinal fluid in humans after a bolus intravenous injection and during a controlled, continuous intravenous infusion. All the patients were studied in a steady-state and crossover fashion. In plasma, the mean peak level after bolus injection (1.5 g) studied in 12 patients was 206.5 mug/ml; during continuous infusion (6 g daily), the mean level remained stable at 52.6 mug/ml. With bolus injection and continuous infusion, respectively, 89.7 and 86.3% of the administered dose of cefazolin were excreted in the urine of nine patients over the 6-h period considered. The levels of cefazolin in common bile duct bile were studied in six cholecystectomized patients. In bile collected during the two 3-h periods of the experiment, the mean concentration of the drug in the bile after bolus injection was 66.9 and 22.0 mug/ml, respectively; during continuous infusion, the corresponding biliary levels were 50.7 and 51.3 mug/ml, respectively. In four neurosurgical patients with an intraventricular catheter, neither bolus injection nor continuous infusion resulted in a demonstrable concentration of cefazolin in the cerebrospinal fluid. The continuous intravenous administration of cefazolin might have some advantage over the intravenous bolus intermittent injections. In plasma, the area under the curve is greater with continuous infusion than with bolus injection. In bile, the levels of cefazolin are more sustained with continuous infusion than with bolus injection. This approach to intravenous administration of cefazolin deserves more pharmacological and clinical trials.

[Angiomas of the epidural space (author's transl)]. / Angiomes de l'espace épidural

The authors describe two cases of angiomas strictly limited to the spinal epidural space. They review the literature and stress the rarity of these tumours.

[Pathological findings in a case of normal pressure hydrocephalus (author's transl)]. / Constatations anatomo-pathologiques dans un cas d'hydrocéphalie normotensive

Pathological findings in a case of normal pressure hydrocephalus are reported with a review of the literature.