The influence of prosthesis size and design on exercise dynamics after aortic valve replacement.

BACKGROUND AND AIM OF THE STUDY: Residual gradient following aortic valve replacement (AVR) may adversely affect clinical outcome. The size and design of the valve may influence these characteristics. The study aim was to determine the influence of prosthesis physical size and leaflet design on hemodynamic performance after mechanical AVR. METHODS: After AVR, two patient groups with a range of valve sizes were studied. Group 1 patients (n=19) each received a monoleaflet valve; group 2 patients (n=18) each received a bileaflet valve. Transthoracic echocardiography was performed at rest and after graded bicycle ergometry to assess prosthetic valve parameters, including mean and peak transvalvular gradient and effective orifice area (EOA). RESULTS: Transprosthetic gradients (mean and peak) measured at rest, maximum exercise and 3-min recovery were related to indexed geometric orifice area (IGOA) by an exponential decay function, with no significant advantage for either valve design. However, in valve sizes < or =25 mm the bileaflet valves demonstrated lower gradients, both at rest and under exercise conditions (mean gradient during exercise, bileaflet versus monoleaflet 19.9 +/- 7.2 mmHg versus 25.6 +/- 6.3 mmHg, p = 0.01). Similarly, EOAs were larger in the bileaflet group when equivalent GOAs < or =2.5 cm2 were compared (EOA: bileaflet versus monoleaflet 1.51 +/- 0.33 cm2 versus 1.14 +/- 0.26 cm2, p = 0.018). The total work performed correlated with prosthesis diameter (r2 = 0.81, p = 0.037) and was not influenced by valve design. CONCLUSION: The hemodynamic performance of mechanical aortic valves, including transprosthetic gradient and maximum exercise work performed, related principally to the prosthesis physical size. However, within the smaller valve sizes, the bileaflet design appeared to offer hemodynamic advantages.

The generalized tonic-clonic seizure in partial versus generalized epilepsy: semiologic differences.

PURPOSE: To study differences in the clinical manifestations of generalized tonic-clonic seizures (GTCS) of partial versus generalized onset. METHODS: We studied 10 GTCSs in nine patients with idiopathic generalized epilepsy (IGE) and 10 GTCSs in 10 patients with temporal lobe epilepsy (TLE). Videotaped seizures were reviewed for all clinical features, focusing on asymmetries during different phases of each seizure. RESULTS: In the IGE group, focal features were seen before generalized motor activity in seven seizures. The most common was adversive head turn (six seizures). One patient had opposite direction of head turning in two recorded seizures. The tonic phase was always symmetric. In the last generalized clonic phase, asymmetry or asynchrony of motor activity was seen transiently in three seizures. The TLE group showed focal features before generalization in all seizures. Adversive head turning occurred in nine patients and was always contralateral to the focus. Focal clonic activity occurred before generalization in three and was always contralateral to the focus. The generalized tonic phase was usually asymmetric, and in the last clonic phase, motor activity was asymmetric or asynchronous in eight seizures (p<0.05, IGE vs. TLE). CONCLUSIONS: Brief focal features or asymmetry at onset are common in the GTCSs of IGE. However, asymmetry or asynchrony during the last clonic phase are uncommon in IGE, in contrast to TLE.

Meningoencephalitis: an atypical presentation of herpes simplex type 2 central nervous system infection.

Encephalitis is the best recognized form of central nervous system (CNS) infection with the herpes simplex virus. We present a case of meningoencephalitis with a benign course caused by herpes simplex virus type 2. The patient had no focal abnormalities on either brain magnetic resonance imaging scan or electroencephalogram. The cerebrospinal fluid profile was that of aseptic meningitis, with a lymphocytic pleocytosis. The clinical spectrum of herpes simplex infections in the CNS is broad. Specifically, herpes simplex type 2 can cause a benign meningoencephalitis with scant focal findings, in addition to the known encephalitis and more recently recognized benign recurrent lymphocytic meningitis.

The opercular-subopercular syndrome: four cases with review of the literature.

We present four cases of the 'opercular syndrome' of volitional paresis of the facial, lingual, and laryngeal muscles (bilateral facio-glosso-pharyngo-masticatory paresis). Case histories and CT brain images are presented, along with a review of the literature concerning this long-recognized but little-known syndrome. The neuroanatomic basis of the syndrome classically involves bilateral lesions of the frontal operculum. We propose, on the basis of our cases and others, that the identical syndrome can arise from lesions of the corticobulbar tracts, not involving the cortical operculum. Our cases included one with bilateral subcortical lesions, one with a unilateral left opercular lesion and a possible, non-visualized right hemisphere lesion, one with unilateral cortical and unilateral subcortical pathology, and one with bilateral cortical lesions. These lesion localizations suggest that any combination of cortical or subcortical lesions of the operculum or its connections on both sides of the brain can produce a syndrome indistinguishable from the classical opercular syndrome. We propose the new term 'opercular-subopercular syndrome' to encompass cases with predominantly or partially subcortical lesions.