Normal physiological emotions but differences in expression of conscious feelings in children with high-functioning autism.

To provide insight into what aspects of the emotional circuit might be affected in high-functioning autism, we measured indices of physiological emotions and of the expression of conscious feelings in 10 children with high-functioning autism or Asperger syndrome and 10 comparison participants. Pleasant, unpleasant, and neutral pictures were presented while skin conductance responses were measured. Self-report ratings of pleasantness and interestingness were taken between pictures. Skin conductance responses did not differ between the groups. Self report ratings were different, with the children with autism giving more similar answers to the two questions than the comparison children. Impairments in socio-emotional expression in autism may be related to deficits in perception and/or expression of conscious feelings; physiological emotions may be relatively preserved.

Subtle executive impairment in children with autism and children with ADHD.

BACKGROUND: The executive functions of inhibition, planning, flexible shifting of actions, and working memory are commonly reported to be impaired in neurodevelopmental disorders. METHOD: We compared these abilities in children (8-12 years) with high functioning autism (HFA, n = 17), attention deficit-hyperactivity disorder (ADHD, n = 21) and healthy controls (n = 32). Response inhibition was assessed using the Stroop Color and Word Test (Golden, 1978). Problem solving, set-shifting, and nonverbal memory were assessed using three tasks, respectively, from the CANTAB (Cambridge Cognition, 1996): the Stockings of Cambridge task; the Intra-Dimensional/Extra-Dimensional set-shifting task; and the Spatial Working Memory task (SWM) with tokens hidden behind 3, 4, 6, and 8 boxes. RESULTS: There were no group differences on the response inhibition, planning, or set-shifting tasks. On the SWM task, children with HFA made significantly more between-search errors compared with controls on both the most difficult problems (8-box) and on the mid-difficulty problems (6-box); however, children with ADHD made significantly more errors compared to controls on the most difficult (8-box) problems only. CONCLUSION: Our findings suggest that spatial working memory is impaired in both ADHD and HFA, and more severely in the latter. More detailed investigation is needed to examine the mechanisms that differentially impair spatial working memory, but on this set of tasks there appears to be sparing of other executive functions in these neuropsychiatric developmental disorders.

Deficits in the initiation of eye movements in the absence of a visual target in adolescents with high functioning autism.

BACKGROUND: We used ocular motor paradigms to examine whether or not saccades are impaired in individuals with high functioning autism (HFA). METHODS: We recorded eye movements in patients with HFA (n=11), and in normal adolescents (n=11) on anti-saccade, memory-guided saccade (MGS), predictive saccade and gap/overlap tasks. RESULTS: Compared with the normal subjects, patients with HFA had (1) a significantly higher percentage of directional errors on the anti-saccade task (63.2% versus 26.6%), (2) a significantly higher percentage of response suppression errors on a MGS task (60.3% versus 29.5%) and (3) a significantly lower percentage of predictive eye movements on a predictive saccade task. They also showed longer latencies on a MGS task and for all conditions tested on a gap/null/overlap task (fixation target extinguished before, simultaneously, or after the new peripheral target appeared). When the latencies during the gap condition were subtracted from the latencies in the overlap condition, there was no difference between patients and normals. CONCLUSIONS: Abnormalities in ocular motor function in patients with HFA provide preliminary evidence for involvement of a number of brain regions in HFA including the dorsolateral prefrontal cortex (dlPFC) and the frontal eye fields (FEFs) and possibly the basal ganglia and parietal lobes.

The influence of binocular visual deprivation on the development of visual-spatial attention.

This article examines the effects of visual input on the development of attention by comparing normal children to children, all more than 8 years old, who had been treated for bilateral congenital cataracts during infancy. In Experiment 1, patients pushed a button as soon as they detected a target that appeared 100, 400, or 800 msec after a central cue. The cue either validly cued the upcoming location or invalidly cued the wrong location. Patients (n = 16) performed normally at the 100 msec and 400 msec stimulus onset asynchrony (SOA). However, when the cue preceded the target by the 800 msec SOA, patients' reaction times were not affected by the validity of the cue, especially when deprivation had extended past 4 months of age. In Experiment 2, patients indicated which of two shapes appeared in the periphery 400 msec after a central cue, with those shapes surrounded by compatible or incompatible distractors. Patients (n = 15) differed from age-matched controls in (a) being slowed more by incompatible distractors on invalid trials, and (b) tending to show a larger than normal effect of the validity of the cue preceding targets in the upper visual field. Together, these findings suggest that the normal development of attention is influenced by early visual experience.

Evidence for a deficit in procedural learning in children and adolescents with autism: implications for cerebellar contribution.

To examine the hypothesis that abnormalities in those cognitive functions for which cerebellar components have been implicated contribute to the pathophysiology of autism, tests of judgment of explicit time intervals and procedural learning were administered to 11 participants with autism and 17 age-and-IQ-matched controls. Results indicated that the group with autism demonstrated significant impairments in procedural learning compared with the group of controls. No significant difference in judgment of explicit time intervals was found. The data suggest that deficits in procedural learning may contribute to the cognitive and behavioral phenotype of autism; these deficits may be secondary to abnormalities in cerebellar-frontal circuitry.

Evidence of normal cerebellar control of the vestibulo-ocular reflex (VOR) in children with high-functioning autism.

The effect of "tilt-suppression" on post-rotatory vestibular nystagmus was investigated to assess the function of the caudal cerebellar vermis (lobules IX and X, or nodulus and uvula) in 13 school-age children with high-functioning autism (HFA) and 10 normal controls. Tilt-suppression of the vestibulo-ocular reflex (VOR) refers to the decreasing of the duration of post-rotatory vestibular nystagmus that occurs when the head is moved out of the plane in which it was located during the previous sustained constant-velocity rotation. The participant is rotated in a vestibular chair with the head upright and then the head is tilted forward just after the chair stops rotating. Such tilt-suppression is impaired with lesions of the cerebellar nodulus and portions of the uvula. Results show that children with HFA have normal post-rotatory nystasmus with the head upright and normal attenuation of post-rotatory nystagmus induced by head tilt. These behavioral findings suggest that lobules IX and X of the cerebellum are spared in high-functioning autism.

Effects of acute prednisone administration on memory, attention and emotion in healthy human adults.

We conducted a double-blind study in order to examine the effects of high doses of prednisone on memory, attention and emotion in humans. A total of 24 healthy undergraduate males self-administered either 160 mg of prednisone (n = 12) or a placebo (n = 12) for 4 consecutive days. We examined group differences in mood, regional brain electrical activity (EEG), the startle eyeblink response, memory recall and performance on an attention task after 4 days of treatment. We found significant group differences on measures of mood and frontal EEG alpha activity on 4-day treatment. Subjects treated with prednisone exhibited a significantly greater increase in self-reported negative emotion and greater relative right frontal EEG alpha activity on 4-day treatment compared with adults in the placebo group. We also found that subjects treated with prednisone recalled fewer objects on the memory task following treatment. No significant group differences were found on posterior EEG activity, the startle eyeblink measure, or the attention measure. These findings suggest that administration of high doses of exogenous prednisone may facilitate the experience of negative emotion and shifts in frontal EEG activity, and impair some aspects of cognitive functioning in humans. The multiple roles of glucocorticoids in memory, attention and emotion are discussed.

Patency of infrainguinal polytetrafluoroethylene bypass grafts with distal interposition vein cuffs.

Polytetrafluoroethylene (PTFE) prosthetic bypasses in the lower extremity have poor patency rates, particularly in limb salvage cases. Patency and limb salvage rates of PTFE bypasses supplemented by distal interposition vein cuffs were assessed in patients requiring revascularization for critical limb ischemia, in the absence of a suitable autologous saphenous vein. Between October 1993 and April 1996, 163 patients underwent 185 infrainguinal bypasses. Forty-three limbs in 42 patients (12 women, 30 men; mean age 67 years) did not have a suitable autologous saphenous vein (24%) and had femoropopliteal (20) and infrapopliteal (23) bypasses performed. Patients were examined prospectively at 3-month intervals during the first year and at 6-month intervals thereafter to determine graft patency and limb salvage. Postoperative anticoagulation with warfarin was used in 26 patients. Indications for operation included limb salvage in 41 extremities (21 rest pain/ulceration or gangrene, 20 rest pain alone), and disabling claudication in two. Patients were followed clinically for 2-30 months (mean 10 months). Cumulative 2-year life-table patencies for all grafts, femoropopliteal and infrapopliteal bypasses were 64%, 75% and 62%, respectively. Previous primary patencies at the authors' institution for PTFE bypasses without vein cuffs were 35%, 46% and 12% for the same categories. Cumulative life-table limb salvage for all PTFE/vein cuff bypasses in the present series was 76% compared with 37% in previous PTFE bypasses without vein cuffs. Adjunctive use of distal interposition vein cuffs improves prosthetic graft patency, while producing satisfactory limb salvage. Postoperative anticoagulation did not influence graft patency. PTFE/vein cuff for lower-extremity revascularization shows good 2-year patency and is an acceptable alternate conduit in patients with critical limb ischemia when autologous saphenous vein is absent.

A strategy for increasing use of autogenous hemodialysis access procedures: impact of preoperative noninvasive evaluation.

PURPOSE: We studied the efficacy of preoperative noninvasive assessment of the upper extremity to identify arteries and veins suitable for hemodialysis access to increase our use of autogenous fistulas (AF). METHODS: From Sep. 1, 1994, to Apr. 1, 1997, 172 patients who required chronic hemodialysis underwent segmental upper extremity Doppler pressures and duplex ultrasound with mapping of arteries and veins. The following criteria were necessary for satisfactory arterial inflow: absence of a pressure gradient between arms, patent palmar arch, and arterial lumen diameter 2.0 mm or more. The criteria necessary for satisfactory venous outflow were venous luminal diameter greater than or equal to 2.5 mm for AF and greater than or equal to 4.0 mm for synthetic bridging grafts (BG) and continuity with distal superficial veins in the arm. Intraoperative and duplex ultrasound measurements were compared. Contemporary experience was compared with the 2-year period (1992 to 1994) before implementation of the protocol. RESULTS: During the period from Sep. 1, 1994, to Apr. 1, 1997, 108 patients (63%) had AF, 52 (30%) had prosthetic BG, and 12 (7%) had permanent catheters (PC) placed. Early failure was seen in 8.3% of AFs. Primary cumulative patency rates were 83% for AF and 74% for BG at 1 year (p < 0.05), with a mean clinical follow-up of 15.2 months. No postoperative infections were observed with AF, whereas six infections (12%) were observed with BG and two (17%) with PC insertion. During the period from June 1, 1992, to Aug. 31, 1994, 183 procedures were performed with a distribution of 14% AF, 62% BG, and 24% PC. In this earlier period the AF early failure rate was 36%, and the patency rates were 48%, 63%, and 48% for AF, BG, and PC, respectively (mean follow-up, 13.8 months). CONCLUSION: A protocol of noninvasive assessment increased use of AFs. The cumulative patency rate of AFs was improved, and early failure rates were reduced when compared with the preceding institutional experience. Routine noninvasive assessment is recommended to document adequacy of arterial inflow and delineate venous outflow to maximize opportunities for AF.

Morphometric assessment of the dermal microcirculation in patients with chronic venous insufficiency.

PURPOSE: Ultrastructural assessments of the dermal microcirculation in patients with chronic venous insufficiency have been limited to qualitative morphologic descriptions of venous ulcer edges or venous stasis dermatitis. The purpose of this investigation was to quantify differences in endothelial cell structure and local cell type with emphasis on leukocytes and their relationship to arterioles, capillaries, and postcapillary venules (PCVs). METHODS: Two 4.0 mm punch biopsies were obtained from areas of dermal stasis skin changes in the gaiter region of the leg, as well as from noninvolved areas of skin in the ipsilateral thigh, from 35 patients: CEAP class 4 (11 patients), class 5 (9 patients), class 6 (10 patients), and five normal skin biopsies from patients without chronic venous insufficiency. Electron microscopy was performed on sections at 6700x and 23,800x magnification. At 6700x endothelial cell thickness was determined, and the number of fibroblasts, leukocytes, and mast cells were recorded relative to their proximity to arterioles, capillaries, and PCVs. Similarly, at 23,800x endothelial cell vesicle density, interendothelial junctional widths, and basal lamina thickness (cuff width) were measured. Preliminary evaluation for the presence of transforming growth factor-beta 1 (TGF-beta 1) was performed on three patients using reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: Quantitative measurements demonstrated increased mast cell content for class 4 and 5 patients around arterioles and PCVs and increased macrophage numbers for class 6 patients around PCVs (p < 0.05). Fibroblasts were the most common cells observed; however, no differences were demonstrated between groups. No differences were observed in interendothelial junctional widths or vesicle densities in arterioles, capillaries, or PCVs. Basal lamina thickness was increased only at the capillary level (p < 0.05). The results of RT-PCR for TGF-beta 1 messenger RNA were positive in the three patients studied. CONCLUSIONS: Our data suggest that (1) mast cells play a role in the pathogenesis of chronic venous insufficiency; (2) the effects of mast cells, macrophages, or both may be mediated in part by TGF-beta 1; and (3) capillary cuff formation is not associated with widened interendothelial gap junctions, but may be a result of enhanced vesicular transport rate or conformational changes in the interendothelial glycocalyx.

Vein transposition in the forearm for autogenous hemodialysis access.

PURPOSE: We describe a technique of superficial venous transposition in the forearm used for the formation of an arteriovenous fistula for hemodialysis access. These modifications of the single-incision radiocephalic fistula are designed to increase options for arteriovenous fistulas by using veins and arteries that are suitable for use but are not in immediate proximity. METHODS: Arteries and veins suitable for a primary arteriovenous fistula were identified and mapped using duplex ultrasound in 89 patients. Separate incisions were used in the majority of cases, and the selected forearm vein was mobilized, angiodilated, and transposed into a subcutaneous tunnel on the volar aspect of the forearm. Before initiation of hemodialysis, duplex ultrasound scanning was performed, and the location that was most suitable for cannulation was identified. Repeat scans were performed at 3-month intervals for analysis of patency. RESULTS: Superficial venous transpositions were performed using a single incision in 13 instances in which the vein was in immediate proximity to the radial artery (type A). Dorsal-to-volar forearm transposition (type B) was performed in 30 veins with anastomoses to the radial (n = 26), ulnar (n = 2), or brachial (n = 2) arteries. Volar-to-volar forearm transposition (type C) was performed in the remaining 46 veins, with anastomoses to the radial (n = 42), ulnar (n = 2), or brachial arteries (n = 2). Successful hemodialysis was accomplished in 81 of 89 patients (91%). The primary cumulative patency rate was 84% at 1 year and 69% at 2 years. The mean duration of follow-up was 14.3 months. CONCLUSIONS: The use of superficial venous transposition for the formation of autogenous hemoaccess was associated with ease of cannulation by dialysis personnel, high maturation rates, reduced early failure rates, and enhanced patency rates. We recommended the use of these technical modifications to increase the use of autogenous fistulas in the forearm.

A program of operative angioplasty: endovascular intervention and the vascular surgeon.

PURPOSE: Vascular surgeons are ideally suited to select and perform endovascular interventions either as primary therapy or as an adjunct to bypass surgery. Attaining proficiency in endovascular techniques is an important goal in the training of vascular surgeons. We report our initial experience with a program of endovascular intervention performed in the operating room by vascular surgeons. METHODS: During the previous three years, we performed 109 angioplasty procedures, 60 aortoiliac (55%), 32 femoropopliteal (29%), and 17 popliteal/tibial (16%), using guidewires and angioplasty balloons directed by intraoperative digital subtraction C-arm arteriography with road-mapping capabilities. Indications for angioplasty included disabling claudication in 59 patients (54%), rest pain in 18 (17%), and tissue loss in 32 (29%). Angioplasty was accompanied by stent placement in 39 of 60 aortoiliac procedures (65%) and in two of 32 femoral procedures (6%). In 16 cases (15%), the endovascular procedure was performed in conjunction with a bypass procedure. In selected cases (15, 14%), duplex scanning was the sole diagnostic method used before surgery to identify the lesion, eliminating the need for preoperative arteriographic scans. Segmental pressure measurements, duplex ultrasound scans, and treadmill exercise testing as indicated were performed before and after surgery. The efficacy of the endovascular intervention was assessed at 3-month intervals during the first year and at 6-month intervals thereafter. RESULTS: A successful results was defined using criteria recommended by the Ad Hoc Subcommittee on Reporting Standards for Endovascular Procedures from the Society for Vascular Surgery/International Society for Cardiovascular Surgery. This included the combination of symptomatic improvement, obtaining an anatomically successful result with < 30% residual lumen stenosis, and elimination of the translesion gradient with an improvement in high thigh-brachial index or ankle-brachial index greater than 0.15. Initial success was achieved in 55 of 60 aortoiliac (92%), 28 of 32 femoropopliteal (88%), and 16 of 17 popliteal/tibial (94%) angioplasty procedures. Clinical follow-up has been achieved in all cases, with continued clinical success rates of 80%, 75%, and 82% for aortoiliac, femoropopliteal, and popliteal/tibial angioplasty procedures, respectively, with a mean follow-up of 15.7 months. CONCLUSION: These results confirm the value of a program in which C-arm technology was used by vascular surgeons in the performance of angioplasty and stenting procedures in the operating room. This experience in therapeutic endovascular intervention will facilitate the credentialing process for future vascular surgeons.

The effects of embolectomy-thrombectomy catheters on vascular architecture.

The purpose of this report is to describe the evolution of an embolectomy-thrombectomy catheter (ETC) injury over a six week period. Carotid arteries and jugular veins in six adult dogs were subjected to ETC withdrawals at a standard velocity and balloon size. Vascular segments were excised as early as one hour and as late as six weeks. The specimens were prepared for light, scanning electron and transmission electron microscopic examination. In early specimens, arteries and veins showed endothelial denudation followed by regeneration. In later specimens, the arteries showed progressive disruption of the internal elastic lamina and marked subendothelial proliferation (arteriosclerosis). By the sixth week the artery's intima was equal in thickness to the media. The veins showed only regenerating endothelium without alterations of the subendothelium. Exposure of canine vasculature to ETC procedures caused pronounced transmural damage in the arteries and only endothelial alterations in the veins.