Hemiplegic migraine during pregnancy: unusual magnetic resonance appearance with SPECT scan correlation.

OBJECTIVE: This article discusses the pathophysiology and implications for treatment of hemiplegic migraine within a case study presentation. BACKGROUND: We evaluated a 31-year-old white woman for hemiplegia in her 36th week of pregnancy. She initially presented with severe headache, dysarthria, lethargy, and left-sided numbness and weakness. Hemiplegic migraine remains a diagnosis made by exclusion; neurologic examination of these patients is localizing, but nonspecific. DESIGN: Magnetic resonance imaging and single photon emission computed tomography scanning were performed on this patient during an exacerbation of headache associated with dense hemiplegia. RESULTS: Magnetic resonance imaging showed a superficial cerebral hemispheric signal abnormality with enhancement. Single photon emission computed tomography scanning confirmed hyperperfusion of that hemisphere. CONCLUSIONS: We believe the imaging evidence in our patient suggests that hemiplegia was caused and sustained by hyperperfusion. This case lends supportive evidence to a primarily vasodilatory mechanism and hyperperfusion as an etiology of the paralysis in such headaches and perhaps migraine with aura.

Teloscopy after bladder neck suspension.

Teloscopy, a method of suprapubic cystoscopy, involves placing a telescope into the dome of a full bladder to examine the bladder interior. A 5-mm Dexide cannula was pierced through the dome of the bladder and a telescope was inserted through it. This specialized cannula sleeve maintained bladder distention and allowed an excellent wide-angle view of the interior of the bladder and ureteral orifices. In a retrospective analysis, 103 consecutive women with stress urinary incontinence who underwent retropubic urethropexy were placed into one of three categories: Burch laparotomy (13), Burch laparoscopy (44), or laparoscopy with mesh and staples (46). Teloscopy was performed and indigo carmine was given intravenously at the end of the procedure in 90 patients. Of these, seven (8%) were positive. In all seven a suture was seen through the bladder mucosa, and in five an additional obstructed ureter was observed. In all seven women the suture was removed and replaced, and all obstructed ureters were patent before the end of the procedure. Average time required was 4 minutes. No complications, short- or long-term, occurred in the 90 women. Our results support the view that cystoscopy should be performed at the end of bladder neck suspension.

Geochemical evidence for a comet shower in the late Eocene.

Analyses of pelagic limestones indicate that the flux of extraterrestrial helium-3 to Earth was increased for a 2.5-million year (My) period in the late Eocene. The enhancement began approximately 1 My before and ended approximately 1.5 My after the major impact events that produced the large Popigai and Chesapeake Bay craters approximately 36 million years ago. The correlation between increased concentrations of helium-3, a tracer of fine-grained interplanetary dust, and large impacts indicates that the abundance of Earth-crossing objects and dustiness in the inner solar system were simultaneously but only briefly enhanced. These observations provide evidence for a comet shower triggered by an impulsive perturbation of the Oort cloud.

The Clementine bistatic radar experiment.

During the Clementine 1 mission, a bistatic radar experiment measured the magnitude and polarization of the radar echo versus bistatic angle, beta, for selected lunar areas. Observations of the lunar south pole yield a same-sense polarization enhancement around beta = 0. Analysis shows that the observed enhancement is localized to the permanently shadowed regions of the lunar south pole. Radar observations of periodically solar-illuminated lunar surfaces, including the north pole, yielded no such enhancement. A probable explanation for these differences is the presence of low-loss volume scatterers, such as water ice, in the permanently shadowed region at the south pole.

The clementine mission to the moon: scientific overview.

In the course of 71 days in lunar orbit, from 19 February to 3 May 1994, the Clementine spacecraft acquired just under two million digital images of the moon at visible and infrared wavelengths. These data are enabling the global mapping of the rock types of the lunar crust and the first detailed investigation of the geology of the lunar polar regions and the lunar far side. In addition, laser-ranging measurements provided the first view of the global topographic figure of the moon. The topography of many ancient impact basins has been measured, and a global map of the thickness of the lunar crust has been derived from the topography and gravity.

The South pole region of the moon as seen by clementine.

The Clementine mission has provided the first comprehensive set of high-resolution images of the south pole region of the moon. Within 5 degrees of latitude of the pole, an area of an estimated 30,000 square kilometers remained in shadow during a full lunar rotation and is a promising target for future exploration for ice deposits. The Schrödinger Basin (320 kilometers in diameter), centered at 75 degrees S, is one of the two youngest, least modified, great multiring impact basins on the moon. A large maar-type volcano localized along a graben within the Schrödinger Basin probably erupted between 1 and 2 billion years ago.

Hubble space telescope observations of comet p/shoemaker-levy 9 (1993e).

The Hubble Space Telescope observed the fragmented comet P/Shoemaker-Levy 9 (1993e) (P indicates that it is a periodic comet) on 1 July 1993. Approximately 20 individual nuclei and their comae were observed in images taken with the Planetary Camera. After subtraction of the comae light, the 11 brightest nuclei have magnitudes between approximately 23.7 and 24.8. Assuming that the geometric albedo is 0.04, these magnitudes imply that the nuclear diameters are in the range approximately 2.5 to 4.3 kilometers. If the density of each nucleus is 1 gram per cubic centimeter, the total energy deposited by the impact of these 11 nuclei into Jupiter's atmosphere next July will be approximately 4 x 10(30) ergs ( approximately 10(8) megatons of TNT). This latter number should be regarded as an upper limit because the nuclear magnitudes probably contain a small residual coma contribution. The Faint Object Spectrograph was used to search for fluorescence from OH, which is usually an excellent indicator of cometary activity. No OH emission was detected, and this can be translated into an upper limit on the water production rate of approximately 2 x 10(27) molecules per second.

Primary angiitis of the central nervous system: unusual MR appearance.

The MR findings of a biopsy-proved case of primary angiitis of the central nervous system are described and compared with previously reported cases. Multiple punctate and linear areas of gadopentetate dimeglumine enhancement were present in the brain stem and white matter and appear to correspond to the inflammatory reaction of the small perforating vessels and perivascular tissues seen in the pathologic specimen.

Epidural abscess of the cervical spine: MR findings in five cases.

Cervical epidural abscess is an uncommon infectious process of the spinal epidural space. Although this disorder is often unsuspected clinically, the patient's signs and symptoms may suggest other diagnoses that frequently lead to an MR examination. We retrospectively reviewed the MR examinations of five patients with surgically proved cervical epidural abscess in order to assist in the diagnosis of this clinically elusive disorder. Each epidural abscess was evaluated for MR signal intensity, location, extent, delineation, and enhancement pattern. We assessed the spinal cord for compression and signal intensity and analyzed the vertebrae, intervertebral disks, and paraspinal soft tissue. Compared with the spinal cord, the abscess was isointense or hypointense on T1-weighted spin-echo images and hyperintense on T2-weighted images. The abscess was hyperintense or isointense relative to the cord on T2* gradient-echo images. Enhancement of the abscess occurred in the two patients given an IV injection of gadopentetate dimeglumine. The epidural abscess was located anteriorly in three patients, posteriorly in one, and was circumferential in one. The abscess extended from two to nine vertebral bodies in length. In each case, the abscess caused some degree of spinal cord compression, and one patient had bright signal intensity within the cord on T2-weighted images. Three patients had MR changes of accompanying osteomyelitis and paravertebral abscess. MR imaging is useful in diagnosing cervical epidural abscess and in evaluating associated abnormality of the spinal cord, vertebral bodies, intervertebral disks, and paraspinal soft tissue.

CT and MR appearance of cervical acrylic struts.

A patient sustained trauma to the cervical spine and underwent surgical fusion that included the use of methyl methacrylate struts. The CT and MR appearances of these acrylic struts are described.

Triton's Geyser-Like Plumes: Discovery and Basic Characterization.

At least four active geyser-like eruptions were discovered in Voyager 2 images of Triton, Neptune's large satellite. The two best documented eruptions occur as columns of dark material rising to an altitude of about 8 kilometers where dark clouds of material are left suspended to drift downwind over 100 kilometers. The radii of the rising columns appear to be in the range of several tens of meters to a kilometer. One model for the mechanism to drive the plumes involves heating of nitrogen ice in a subsurface greenhouse environment; nitrogen gas pressurized by the solar heating explosively vents to the surface carrying clouds of ice and dark partides into the atmosphere. A temperature increase of less than 4 kelvins above the ambient surface value of 38 +/- 3 kelvins is more than adequate to drive the plumes to an 8-kilometer altitude. The mass flux in the trailing clouds is estimated to consist of up to 10 kilograms of fine dark particles per second or twice as much nitrogen ice and perhaps several hundred or more kilograms of nitrogen gas per second. Each eruption may last a year or more, during which on the order of a tenth of a cubic kilometer of ice is sublimed.

Voyager 2 in the uranian system: imaging science results.

Voyager 2 images of the southern hemisphere of Uranus indicate that submicrometersize haze particles and particles of a methane condensation cloud produce faint patterns in the atmosphere. The alignment of the cloud bands is similar to that of bands on Jupiter and Saturn, but the zonal winds are nearly opposite. At mid-latitudes (-70 degrees to -27 degrees ), where winds were measured, the atmosphere rotates faster than the magnetic field; however, the rotation rate of the atmosphere decreases toward the equator, so that the two probably corotate at about -20 degrees . Voyager images confirm the extremely low albedo of the ring particles. High phase angle images reveal on the order of 10(2) new ringlike features of very low optical depth and relatively high dust abundance interspersed within the main rings, as well as a broad, diffuse, low optical depth ring just inside the main rings system. Nine of the newly discovered small satellites (40 to 165 kilometers in diameter) orbit between the rings and Miranda; the tenth is within the ring system. Two of these small objects may gravitationally confine the e ring. Oberon and Umbriel have heavily cratered surfaces resembling the ancient cratered highlands of Earth's moon, although Umbriel is almost completely covered with uniform dark material, which perhaps indicates some ongoing process. Titania and Ariel show crater populations different from those on Oberon and Umbriel; these were probably generated by collisions with debris confined to their orbits. Titania and Ariel also show many extensional fault systems; Ariel shows strong evidence for the presence of extrusive material. About halfof Miranda's surface is relatively bland, old, cratered terrain. The remainder comprises three large regions of younger terrain, each rectangular to ovoid in plan, that display complex sets of parallel and intersecting scarps and ridges as well as numerous outcrops of bright and dark materials, perhaps suggesting some exotic composition.

Copper deficiency in Helianthus annuus L.: developmental and metabolic consequences, stomatal function and senescence.

The effects of copper deficiency on developmental morphology and on age related metabolic activity, water utilization, stomatal response to light and leaf senescence in the sunflower, Helianthus annuus L., were monitored by sampling single leaves representing each leaf pair at designated harvest times during much of the vegetative lifespan. Plants grown in nutrient solutions lacking copper exhibited no apparent abnormalities during early vegetative growth and leaf morphology differed little from controls. There were no significant differences in rates of respiratory oxygen uptake of basal leaves between minus copper and controls. The effects of copper deficiency on rates of photosynthetic oxygen evolution were related to leaf age: rates were lower than controls in young basal leaves but higher as these leaves approached senescence. Both respiration and photosynthesis were more susceptible to KCN inhibition in minus copper leaves than in controls. There were no differences in cumulative water use per plant during the first five weeks after transfer of seedlings to nutrient solutions and only minor differences in stomatal aperture and guard cell potassium levels in ambient greenhouse light. Both minus copper and control leaves exhibited a sequential loss of stomatal function. Decay in the turgor driven opening response to light preceded loss of light dependent uptake of potassium into guard cells. Both changes in stomatal response to light occurred before major breakdown of chlorophyll. Basal leaves of sunflowers grown in minus copper nutrient solution tended to be retained longer and exhibited delayed loss of chlorophyll.

A new look at the saturn system: the voyager 2 images.

Voyager 2 photography has complemented that of Voyager I in revealing many additional characteristics of Saturn and its satellites and rings. Saturn's atmosphere contains persistent oval cloud features reminiscent of features on Jupiter. Smaller irregular features track out a pattern of zonal winds that is symmetric about Saturn's equator and appears to extend to great depth. Winds are predominantly eastward and reach 500 meters per second at the equator. Titan has several haze layers with significantly varying optical properties and a northern polar "collar" that is dark at short wavelengths. Several satellites have been photographed at substantially improved resolution. Enceladus' surface ranges from old, densely cratered terrain to relatively young, uncratered plains crossed by grooves and faults. Tethys has a crater 400 kilometers in diameter whose floor has domed to match Tethys' surface curvature and a deep trench that extends at least 270 degrees around Tethys' circumference. Hyperion is cratered and irregular in shape. Iapetus' bright, trailing hemisphere includes several dark-floored craters, and Phoebe has a very low albedo and rotates in the direction opposite to that of its orbital revolution with a period of 9 hours. Within Saturn's rings, the "birth" of a spoke has been observed, and surprising azimuthal and time variability is found in the ringlet structure of the outer B ring. These observations lead to speculations about Saturn's internal structure and about the collisional and thermal history of the rings and satellites.

Encounter with saturn: voyager 1 imaging science results.

As Voyager 1 flew through the Saturn system it returned photographs revealing many new and surprising characteristics of this complicated community of bodies. Saturn's atmosphere has numerous, low-contrast, discrete cloud features and a pattern of circulation significantly different from that of Jupiter. Titan is shrouded in a haze layer that varies in thickness and appearance. Among the icy satellites there is considerable variety in density, albedo, and surface morphology and substantial evidence for endogenic surface modification. Trends in density and crater characteristics are quite unlike those of the Galilean satellites. Small inner satellites, three of which were discovered in Voyager images, interact gravitationally with one another and with the ring particles in ways not observed elsewhere in the solar system. Saturn's broad A, B, and C rings contain hundreds of "ringlets," and in the densest portion of the B ring there are numerous nonaxisymmetric features. The narrow F ring has three components which, in at least one instance, are kinked and crisscrossed. Two rings are observed beyond the F ring, and material is seen between the C ring and the planet.

Volcanic origin of the eruptive plumes on io.

A quadruple long exposure of Io in eclipse exhibits faint auroral emission from the eruptive plumes. No luminous spots in the vents, predicted by Gold, were observed. Heat from the interior of Io appears to be the predominant source of energy in the plumes.