S100beta correlates with neurologic complications after aortic operation using circulatory arrest.

BACKGROUND: Astrocyte protein S100beta is a potential serum marker for neurologic injury. The goals of this study were to determine whether elevated serum S100beta correlates with neurologic complications in patients requiring hypothermic circulatory arrest (HCA) during thoracic aortic repair, and to determine the impact of retrograde cerebral perfusion (RCP) on S100beta release in this setting. METHODS: Thirty-nine consecutive patients underwent thoracic aortic repairs during HCA; RCP was used in 25 patients. Serum S100beta was measured preoperatively, after cardiopulmonary bypass, and 24 hours postoperatively. RESULTS: Neurologic complications occurred in 3 patients (8%). These patients had higher postbypass S100beta levels (7.17 +/- 1.01 microg/L) than those without neurologic complications (3.63 +/- 2.31 microg/L, p = 0.013). Patients with S100beta levels of 6.0 microg/L or more had a higher incidence of neurologic complications (3 of 7, 43%) compared with those who had levels less than 6.0 microg/L (0 of 30, p = 0.005). Retrograde cerebral perfusion did not affect S100beta release. CONCLUSIONS: Serum S100beta levels of 6.0 microg/L or higher after HCA correlates with postoperative neurologic complications. Using serum S100beta as a marker for brain injury, RCP does not provide improved cerebral protection over HCA alone.

The rehabilitation of attention in individuals with mild traumatic brain injury, using the APT-II programme.

Traumatic brain injury (TBI) is a prevalent cause of cognitive impairments and dysfunctions and affects over 2 million individuals each year. Mild traumatic brain injury (MTBI) is generally defined by a brief loss of consciousness, and post-traumatic amnesia that lasts for less than 24 hours. One region of the brain that is likely affected in patients with MTBI is the pre-frontal cortex. This region mediates several functions, including those required for adequate attention. Three individuals, diagnosed with MTBI and difficulties with attention, volunteered to participate in the study. Individuals were presented with 10 weeks of cognitive retraining with the Attention Process Training-II (APT-II) programme, followed by 6 or 7 weeks of educational and applicational programmes. Cognitive tests were administered both pre- and post-training to assess the effectiveness of the programme. Analysis of the results showed that the APT-II programme improved attention and performance speed in each of the three individuals. In addition, any rehabilitated cognitive skills remained stable in each individual in the absence of the rehabilitation programme for at least 6 weeks.

A program for neuropsychological investigation of deep brain stimulation (PNIDBS) in movement disorder patients: development, feasibility, and preliminary data.

OBJECTIVE: This technical report and feasibility study propose a standardized method for collecting neuropsychological data in patients undergoing the deep brain stimulation (DBS) procedure. BACKGROUND: Programs for standardizing motor data collected in studies investigating surgical therapies for Parkinson disease are already widely used (e.g., Core Assessment Program for Intracerebral Transplantations). The development and rationale for the proposed Program for Neuropsychological Investigation of Deep Brain Stimulation (PNIDBS) are outlined, and support for the feasibility of these methodologies is provided via preliminary data. METHOD: The PNIDBS includes a core battery of neuropsychological tests that assesses a wide range of cognitive functions (attention, language, visuospatial, memory, and executive) as well as depression. Using the PNIDBS, three Parkinson disease and two dystonia patients were evaluated at baseline and after surgery, once with stimulation off and once with stimulation on. RESULTS: Patients with severe motor disabilities were able to complete the PNIDBS. These preliminary data suggest that the DBS procedure as a whole had a minimal impact on cognitive functioning in most patients studied. There was also some evidence that the one patient who showed cognitive decline after the DBS procedure had demographic and clinical characteristics that may have put him at risk for this decline. CONCLUSIONS: The procedures in the PNIDBS were systematically developed and are feasible to execute. The relatively brief core battery has multiple versions and can be supplemented to meet individual investigator needs. By evaluating the components of the DBS procedure (electrode placement and stimulation), the PNIDBS can address clinical questions regarding the cognitive effects of the DBS procedure as well as investigate basic scientific issues regarding how different cognitive functions are affected when subcortical-prefrontal circuits are manipulated by the DBS procedure.

The relationship between sexual abuse and mild traumatic brain injury.

It remains unclear why some individuals with mild traumatic brain injury (MTBI) complain of cognitive deficits many months after the injury. Given neuropathological changes associated with prolonged stress, such as occurs with repeated sexual abuse (SA), it seems possible that individuals who experienced SA might be predisposed to greater deficits after MTBI. Four groups of subjects were administered measures of cognitive and emotional functioning. These groups were those with MTBI (n = 10), those with a history of SA (n = 10), those with both MTBI and SA (n = 10), and normal control (NC) subjects (n = 10). Compared to the NC subjects, those with MTBI demonstrated deficits in working memory, those with SA demonstrated deficits in executive functioning, and those with both MTBI and SA demonstrated the greatest number of deficits which were in working memory, executive functioning and memory. Tests of anxiety, depression and post-traumatic stress disorder, while demonstrating significant symptoms in all clinical groups, did not correlate with the neuropsychological tests that differentiated the groups.

Deep hypothermic circulatory arrest with and without retrograde cerebral perfusion.

Our study indicated that RCP provided significant protection against both postoperative strokes and early death. However, in the subjects studied, the combined detrimental effects of postoperative stroke, COPD, cardiac complications, and procedures requiring composite valve replacement outweighed the protective benefit afforded by RCP in the prevention of early death. RCP's protective benefit was also diminished in the presence of pre-existing cerebrovascular disease. Although the major factors leading to the incidence of postoperative stroke and early mortality were the etiologies and pathologies brought to the operating theater by the patient, RCP when used in conjunction with DHCA significantly diminished the likelihood of either outcome. Therefore, given its simplicity of application in the surgical repair of aortic arch abnormalities, its indication seems warranted.

Rewarming: comparison of contemporary heat-exchangers.

Heat exchange methods must be efficient in order to minimize the patient's pump time. However, comparisons of heat exchangers have been rare. Therefore, the in vivo functions of the most popular, currently available heat exchangers, Sarns, Cobe, Medtronics Maxima, and an experimental model manufactured by Haemonetics were compared. Thirty-two pigs weighing between 63-74 kg were placed on cardiopulmonary bypass with right atrial and ascending aorta cannulation through a right thoracotomy. Thermocouples were placed in the pump tubing before and after the heat exchangers, in the water line before and after the heat exchangers, in the inlet and outlet line of the pump, and the esophagus, brain, bladder, rectum, liver, myocardium, and tympanic membranes of the pigs. They were cooled until the bladder temperature was reduced to 14 degrees C, and maintained at that temperature for 10 minutes. Rewarming was begun until the bladder temperature became 37 degrees C. The pump flow was maintained between 50-60 ml/kg/min with standard ventilation. Cobe, Sarns, Maxima, and Haemonetics heat exchangers were tested and their function determined by comparing the time necessary for rewarming. The Haemonetics heat exchanger required a significant shorter time than the others to rewarm the pigs to normal bladder temperature (Cobe 82.0 +/- 12.0, Sarns 80.3 +/- 15.4, Maxima 89.0 +/- 13.9 Haemonetics 68.7 +/- 13.4, p < 0.05). The principal advantage was seen at the lowest temperatures between the Haemonetics experimental heat exchanger and the other heat exchangers. No statistically significant superiority was seen at higher temperatures. The current heat exchangers are relatively comparable but improved performance is possible with available technology.

Retrograde cerebral perfusion during profound hypothermia and circulatory arrest in pigs.

The purpose of this study was to evaluate the use of retrograde cerebral perfusion via the superior vena cava during profound hypothermia and circulatory arrest (CA) in pigs. In three groups of 5 pigs each, group A (control) underwent cardiopulmonary bypass and normothermic CA for 1 hour, group B underwent cardiopulmonary bypass, profound hypothermia, and CA (15 degrees C nasopharyngeal) for 1 hour, and group C underwent the same procedure as group B plus retrograde cerebral perfusion. In group A none awoke. In group B, 2 of 5 did not awake and 3 of 5 awoke unable to stand, 2 with perceptive hind limb movement and 1 moving all extremities. In group C all awoke, 4 of 5 able to stand and 1 of 5 unable to stand but moving all limbs. In neurologic evaluation group B had significantly lower Tarlov scores than group C (p = 0.0090). Group B mean wake-up time, plus or minus standard error of the mean, was 124.6 +/- 4.6 minutes versus 29.2 +/- 5.1 in group C (p = 0.0090). In group B late phase CA cerebral blood flow dropped 30.9% +/- 4.8%, but in group C it rose 24.7% +/- 9.3% (p = 0.0007, pooled variance t test, two-tailed). In group B late phase CA brain oxygenation decreased 46.0% +/- 13.9% but it increased 26.1% +/- 5.4% in group C (p = 0.0013). This difference was reduced somewhat during rewarming (B, -21.2% +/- 14.9%; C, 16.4% +/- 4.7%; p = 0.043). Group B rewarming jugular venous O2 saturation was 30.8% +/- 2.5% versus 56.0% +/- 4.4% in group C (p = 0.0011). We conclude that in pigs retrograde cerebral perfusion combined with profound hypothermia during CA significantly reduces neurologic dysfunction, providing superior brain protection.

Retrograde cerebral perfusion: overview, techniques and results.

Cardiovascular surgical repair of arch aneurysms is taking a step forward by going backwards by utilizing retrograde cerebral perfusion. Drs ME DeBakey, ES Crawford, DA Cooley and GC Morris first reported successful resection and repair of a fusiform aneurysm of the aortic arch with replacement graft in 1957. Since then, Crawford and Coselli have pursued materials and techniques which have made this procedure, one which generally resulted in high morbidity and mortality, more viable with decreased morbidity and mortality. Increased numbers of patients are now having this repair and are resuming normal healthy lives after the operation. From February 1992 to October 1993, 88 patients were surgically treated by Coselli who utilized retrograde cerebral perfusion with profound hypothermia and circulatory arrest, thus allowing for repairs that under any other conditions probably could not have been achieved successfully. It is evident that a major determinant for the successful clinical results, in addition to surgical technique and skill, was the employment of profound hypothermia and circulatory arrest. This article will review the techniques and results of aortic arch repair utilizing retrograde cerebral perfusion during circulatory arrest with profound hypothermia to lessen the chance of neurological morbidity following surgical replacement of the transverse aortic arch.

Set-shifting and spatial orientation in patients with Parkinson's disease.

Individuals with Parkinson's disease were compared to normal control subjects on a series of widely used neuropsychological measures. The two groups were matched for gender, handedness, age, education, and occupation. The neuropsychological tests were chosen to measure two specific functions: (a) spatial orientation (i.e., measures of personal orientation, extrapersonal orientation, right/left orientation, and mental rotation), and (b) the ability to shift mental set (e.g., generating responses from alternating categories). The tests chosen to measure spatial orientation had no set-shifting component, and the tests chosen to measure set-shifting had no spatial orientation component. Multivariate statistical analyses revealed a significant difference between the subjects with Parkinson's disease and the control subjects on the measures of set-shifting ability. In contrast, no significant difference between the groups was observed on the measures of spatial orientation. These results are discussed in terms of the current speculation in the literature regarding the relationship between set-shifting deficits and a disruption of dopaminergic fibers to the prefrontal cortex in Parkinson's disease.

Clustering strategies on tasks of verbal fluency in Parkinson's disease.

The verbal output of patients with Parkinson's disease (PD) was analyzed for semantic and phonemic clusters on tasks of verbal fluency. One task required cued retrieval by semantic category (i.e. animals), and one required non-cued retrieval by initial letter (e.g. words beginning with 'F'). Nondemented PD patients (N = 25) produced significantly fewer words on the cued semantic retrieval task than age-, gender- and education-matched normal control subjects (N = 22), but were not impaired on the non-cued letter retrieval task. However, overall, PD patients were able to form more semantic clusters than phonemic clusters. These results are discussed in light of other studies of verbal fluency deficits in patients with PD.

Use of a heat exchanger in liver transplantation.

Of the first 16 patients who underwent orthoptic liver transplantation, 81% were observed to be hypothermic at termination of bypass (x = 34.5 degrees C, n = 16). In response, an in-line heat exchanger was added to the bypass circuit. Subsequently, 72% of the next 11 patients terminated bypass normothermic (x = 38.2 degrees C, n = 11). By removing from the sample those patients who incurred low blood flows, 100% of the patients terminated bypass normothermic (x = 38.2 degrees C, n = 8). At temperatures of 30-33 degrees C cardiac arrhythmias have been observed. Hypothermia has been documented to cause thrombocytopenia and neutropenia which can lead to blood loss. These low counts are only partially reversible with platelet infusion and white blood cells (WBC). The use of an in-line heat exchanger during liver transplantation is essential in preventing hypothermia in our experience.

Neuropsychological aspects of Parkinson's disease.

The neuropsychological effects of Parkinson's disease have gained wide recognition in recent literature. Effects have been documented in almost all areas of cognitive functioning, including general intellectual functioning, visual-spatial functioning, executive functions, attention and memory functions, language functions, and affective processes. Visual-spatial functions, memory functions, and executive functions have received particular interest. This review of the literature is an attempt to tie together the large number of studies in these cognitive areas and to present a suggestion for a comprehensive neuropsychological battery tailored to the patient with Parkinson's disease. Throughout the review, factors relevant to Parkinson's disease, e.g., dementia, motor symptoms, and hemiparkinsonism, are considered.

Effect of inversion on memory for faces in Parkinson's disease and right-hemisphere stroke patients.

Upright and upside-down photographs of faces, schematic drawings of faces, and photographs of houses were presented to patients with Parkinson's disease (PD), patients with right hemisphere stroke (RH), and age-matched normal control subjects (NC) in a forced-choice recognition paradigm. These slides were presented in four orientation conditions: upright at original presentation and at test, upside-down at both, upright initially and upside-down at test, and vice versa. NC subjects recognized faces most accurately when presented in the same orientation both times. This suggests that the information is resistant to mental rotation. Patients with PD recognized faces most accurately when they were presented upright both times, suggesting difficulty with any unusual orientation, consistent with an inability to shift mental set. RH patients, unlike the other groups, did not recognize faces presented upright both times more accurately than those in any other condition. This supports previous studies suggesting a right hemisphere specialization for recognition of upright faces.

Visuospatial orientation in Parkinson's disease.

Visuospatial functioning in patients with Parkinson's disease was investigated using neuropsychological measures of basic visual perception, complex perceptual discrimination, and spatial orientation. Three subgroups of patients were described: (a) those with broadly impaired visuospatial abilities, (b) those with generally intact abilities, and (c) those whose performance on a task of spatial orientation was lower than their performance on a task of complex perceptual discrimination. These subgroup differences were also concordant with three other variables: age, duration of disease, and degree of dementia. It is suggested that decreases in spatial orientation functioning in Parkinson's disease may reflect the speed of progression of this disease.