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Biomedical subjects

J Schatz

Publications and source records attributed to J Schatz.

27 records · Page 2Linked to original sources

Changes in cognitive performance in children with spastic diplegic cerebral palsy following selective dorsal rhizotomy.

Children with cerebral palsy who receive selective dorsal rhizotomy (SDR) for treatment of spasticity may show suprasegmental changes in upper limb function and control of speech musculature. Anecdotal reports suggest that supra-segmental effects may extend to cognitive functions such as attention and language. This study examined the performance of 16 children with spastic diplegic cerebral palsy on tests of visual attention and other cognitive functions 1 day prior to and 6 months following SDR. Children undergoing SDR were compared with 9 children with spastic diplegia, matched for severity of cerebral palsy and amount of therapy, who did not receive SDR, and 24 age- and sex-matched normal children tested at initial and 6-month follow-up sessions. Children with cerebral palsy treated with SDR showed disproportionately greater improvement in specific attentional and cognitive operations than either of the other groups. These results document cognitive changes following SDR which heretofore were reportedly anecdotally. This improvement may be due to improved mood, reduced physical discomfort, increased therapeutic intervention, or possible cortical effects of SDR.

Attention↗

Neuropsychologic effects of stroke in children with sickle cell anemia.

We examined the nature and extent of neuropsychologic impairment in children with sickle cell anemia (SCA) with or without stroke. Twenty-nine children with SCA received cranial magnetic resonance imaging. Strokes were classified into three groups: diffuse cortical stroke (n = 11), anterior stroke (n = 6), or none (n = 12). Children with SCA and 20 age-matched sibling control subjects then received a neurologic examination and a neuropsychologic battery of tests that included motor, verbal, spatial, attentional, and memory measures. Tests of spatial function showed that children with diffuse cortical strokes were impaired, whereas children with anterior lesions had intrusions of irrelevant material during list recall. There were no significant differences between children with stroke and sibling control subjects on motor, verbal, or memory measures. Six children had evidence of stroke on magnetic resonance imaging without any history of a damaging neurologic event. These children had impaired neuropsychologic performance relative to that of sibling control subjects in a pattern similar to that of children with overt stroke. Children with SCA without stroke did not differ from sibling control subjects on any measure. Our results indicate that overt and silent strokes result in lesion-specific neuropsychologic deficits in children with SCA.

Adolescent↗

Effects of the new angiotensin-converting enzyme inhibitor, ramipril, in patients with essential hypertension.

The antihypertensive and hormonal effects of the new angiotensin-converting enzyme (ACE) inhibitor, ramipril, were assessed by means of a single-blind trial in ten unselected patients with mild-to-moderate essential hypertension. After a 2-week period on placebo, 5 mg ramipril was administered once daily for 2 weeks. Blood pressure returned to normal in five patients and decreased in the remaining patients, without significant changes in heart rate or orthostatic hypotension. A fall in blood pressure was apparent within 1-2 h of the first dose; the maximum decrease was reached at 4-6 h and a fall in pressure was still detectable after 24 h. At 24 h post dose angiotensin-converting enzyme activity was suppressed to 40% of the baseline. Blood pressures for the 10 h interval post dosing showed smooth through-the-day control with minimal peak/trough difference in lowering effect. The magnitude of the blood pressure decrement achieved with the inhibitor did not correlate with baseline renin levels or the rise in renin following treatment. No side-effects were noted during the 2-week observation period. The study demonstrates that ramipril, given in a once-daily regimen over a period of 2 weeks, is well tolerated and provides smooth and effective blood pressure control throughout the 24-h interval between doses.

Adult↗

Signal enhancement for detection of specialized atrioventricular conduction system electrograms during open-heart surgery.

A method for signal enhancement of electrograms of the specialized atrioventricular conduction system is presented. This method allows a single electrogram to replace the tracings of bipolar electrograms previously required to ensure recognition of the specialezed conduction system and yet maintains the safety afforded by use of three pairs of recording electrodes. In addition, this new signal is enhanced in magnitude and is always unidirectional (positive). These features are desirable for automated signal recognition. This method therefore provides an important step toward future automation and signal recognition of specialized conduction system electrograms during open-heart surgery.

Animals↗

Left anterior and left posterior hemiblock in tricuspid atresia and transposition of the great vessels: observations and electrocardiographic nomenclature and electrophysiologic mechanisms.

A patient with tricuspid atresia and characteristic electrocardiographic features of counterclockwise and superiorly oriented frontal plane QRS loop (left anterior hemiblock) is presented. Operative intervention resulted in a clockwise and inferior rotation of the frontal QRS loop (left posterior hemiblock) without the development of complete left bundle branch block. This observation suggests that the electrocardiographic pattern of left anterior hemiblock may result from other mechanisms in addition to block of the left bundle branch fibers oriented toward the anterior part of the left ventricle. The case further suggests that electrocardiographic patterns of apparent A-V conduction defects may not be at all associated with true block in the A-V conduction system. Further, it emphasizes the fact that various electrophysiologic mechanisms may account for identical electrocardiographic patterns.

Child↗