Epilepsy and Recursive Consciousness with Special Attention to Jackson's Theory of Consciousness

Summary: John Hughlings Jackson's theory of consciousness has been reconsidered. The author stressed that his uniqueness as a neuroscientist lay in his keen interest in the recursive nature of human consciousness. Two clinical symptoms of interest to Jackson were discussed: recurrent utterances and mental diplopia. Recurrent utterances were believed to represent an exceptional state, in which the unconscious process in speech production, otherwise destined to be swept away automatically, became manifest and observable. Jackson regarded mental diplopia as a revelation of otherwise inaccessible duality of all healthy mental actions. Therefore, he supposed that the essence of recursive consciousness resided in a transformation of multiple, multidirectional, unconscious processes into a linear, unidirectional process     

SARS-CoV-2 Testing Before International Airline Travel,December 2020 to May 2021

Although there have been several case reports and simulation models of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission associated with air travel, there are limited data to guide testing strategy to minimize the risk of SARS-CoV-2 exposure and transmission onboard commercial aircraft. Among 9853 passengers with a negative SARS-CoV-2 polymerase chain reaction test performed within 72 hours of departure from December 2020 through May 2021, five (0.05%) passengers with active SARS-CoV-2 infection were identified with rapid antigen tests and confirmed with rapid molecular test performed before and after an international flight from the United States to Italy. This translates to a case detection rate of 1 per 1970 travelers during a time of high prevalence of active infection in the United States. A negative molecular test for SARS-CoV-2 within 72 hours of international airline departure results in a low probability of active infection identified on antigen testing during commercial airline flight.     

Intranodal Lymphangiography with Thoracic Duct Embolization for Treatment of Chyle Leak after Thoracic Outlet Decompression Surgery

From 2015 to 2019, 9 patients underwent ultrasound-guided intranodal lymphangiography for the treatment of a chyle leak following thoracic outlet decompression surgery. Chyle leaks were identified by Lipiodol (Guerbet, Roissy, France) extravasation near the left supraclavicular surgical bed in all patients. The technical success rate of thoracic duct embolization was 67% (6 of 9), including fluoroscopic transabdominal antegrade access (n = 4) and ultrasound-guided retrograde access in the left neck (n = 2). Clinical success was achieved in 89% of patients (8 of 9). The mean interval from lymphangiography to drain removal was 6.6 days (range, 4–18 d). No patients had a chyle leak recurrence during clinical follow-up (mean, 304 d).     

Comparison of peripheral glucose uptake after oral glucose loading and a mixed meal

Forearm glucose uptake (FGU) and other metabolic responses were studied in six normal men for three hours after a 75-g oral glucose load and a mixed meal containing 75 g carbohydrate. After the meal the rise in arterial glucose levels was considerably less than that following the oral glucose load but the overall insulin responses from 0 to 180 minutes were not statistically different. Although the initial rise in FGU was more gradual after the meal, the subsequent elevation was more sustained and, at the termination of the study, exceeded significantly that seen after the oral glucose load. The rise in GIP levels during the first hour was similar after the meal and the oral glucose load, but thereafter concentrations following the oral glucose load fell while those after the meal continued to rise. When the incremental area (delta) is used as the index of response, the results show that while the glucose response (delta G) after the meal (19.1 +/- 5.3 units) was only 26% of that after oral glucose loading (72.7 +/- 7.0 units), the corresponding increase in FGU (delta FGU) reached 62% (55.0 +/- 12.8 units after the meal, 89.2 +/- 20.0 units after the oral glucose load). Thus, the increase in peripheral glucose uptake relative to the glycemic response (delta FGU/delta G) was significantly greater after the meal than following the oral glucose load alone (P less than 0.05). In conclusion, relative to the rise in arterial glucose levels, peripheral glucose uptake is greater after a meal than after glucose loading with an equivalent carbohydrate challenge. Furthermore, the present data support previous studies emphasizing the failure of GIP alone to explain the entero insular axis.     

Influence of plasma drug level and the presence of conduction disease on the electrophysiologic effects of procainamide.

Electrophysiologic measurements were made in 16 patients before and after the intravenous administration of procainamide. The drug was administered at two different dose levels. The lower plasma procainamide level (6 to 7 μg/ml) caused small decreases in cycle length (848 ± 13 versus 799 ± 42 msec), sinus nodal recovery time (1,166 ± 81 versus 1,024 ± 90 msec at a paced rate of 120 beats/min) and sinoatrial conduction time (105 ± 11 to 90 ± 9 msec). Sinus or atrial echo zones, whether or not they caused supraventricular tachyarrhythmia, were abolished by procainamide in 11 of 13 instances. The higher plasma level of procainamide (10 to 11 μg/ml) generally caused greater changes in electrophysiologic measurements. Atrial refractory periods tended to increase but changed significantly only at higher plasma levels. The latter effect was blunted in patients with a prolonged sinoatrial conduction time. The A-H interval and atrioventricular nodal functional refractory period tended to decrease at higher plasma levels, but not significantly. The H-V interval increased slightly from 48 ± 2 to 52 ± 2 msec; this effect was blunted in patients with bundle branch block.It is concluded that procainamide could be useful in managing supraventricular tachyarrhythmia because it abolishes atrial and sinus echo zones that trigger supraventricular tachyarrhythmia and because its widespread effects make it capable of blocking reentry at several sites. The electrophysiologic effects or procainamide are less predictable in patients with conduction disease, and some effects occur only at high plasma levels.     

Isometric effects on treadmill exercise response in healthy young men

This study evaluated the hypothesis that the isometric stress of load carrying augments the dynamic exercise response seen on the treadmill, and estimated the magnitude of this effect on heart rate and blood pressure for several methods of carrying the same load. Thirteen healthy subjects carried 40 lb in the right hand (H), 40 lb on the back (B), 20 lb in each hand (D) and no weight (N) while walking for 3 minutes on the treadmill at a grade of 0 at 1.7 miles/ hour. A statistically significant increase in the rate of rise and peak levels of systolic blood pressure, heart rate, estimated mean blood pressure, the product of estimated mean blood pressure and heart rate and systolic blood pressure-heart rate product was shown when task H was compared with tasks B, D and N. Values for tasks D and B did not differ significantly.The effects of isometric and dynamic exercise combined were greater than those of dynamic exercise alone. An effective technique of load distribution reduced the rate of increase in blood pressure, heart rate and the peak attained during dynamic exercise, thereby suggesting a lower level of myocardial oxygen consumption for a given weight-carrying task. These results can be applied to evaluation of patients with heart disease and estimation of their exercise tolerance.