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PubMed2003

Visual-spatial ability correlates with efficiency of hand motion and successful surgical performance.

BACKGROUND: This study examines the influence of visual-spatial ability and manual dexterity on surgical performance across 3 levels of expertise. METHODS: Dental students, surgical residents, and staff surgeons completed standardized tests of manual dexterity and visual-spatial ability and were assessed objectively while performing the rigid fixation of an anterior mandible on bench model simulations. Outcome variables included expert assessment of technical performance and efficiency of hand motion during the procedure (recorded using electromagnetic sensors). RESULTS: Visual-spatial scores correlated significantly with surgical performance scores within the group of dental students (r=.40 to.73), but this was not the case for residents or staff surgeons. For all groups, manual dexterity did not correlate with hand motion parameters. There were no differences between groups in visual-spatial ability or manual dexterity, but highly significant differences were seen in surgical performance scores (P<.001), in that surgeons outperformed residents, who in turn outperformed students. CONCLUSIONS: Among novices, visual-spatial ability is associated with skilled performance on a spatially complex surgical procedure. However, advanced trainees and experts do not score any higher on carefully selected visual-spatial tests, suggesting that practice and surgical experience may supplant the influence of visual-spatial ability over time. Thus, the use of these tests for the selection of residents is not currently recommended; they may be of more use in identifying those novice trainees (ie, those with lower test scores) who might benefit most from brief supplementary instruction on specific technical tasks.

Clinical Competence↗

PubMed2000

The Krukenberg procedure: a surgical option for the treatment of double hand amputees in Sierra Leone.

BACKGROUND: For the past 9 years, Sierra Leone has struggled with a cruel civil war in which the civilian population has been the principal target. The International Committee of the Red Cross established a surgical mission in Netland Hospital, Freetown, and during this surgical mission, we treated crippled individuals who had had one or both hands amputated. We assessed the benefit of the Krukenberg procedure to restore manual dexterity in this group. In this operation, radius and ulna are separated and a pincer-like grasp is created. METHODS: From July 15, 1998, to Sept 9, 1998, we carried out the Krukenberg procedure on a group of double and single hand amputees. The main target group was double hand amputees, however, the procedure was initially done on three single hand amputees to assess the functional result. Between the original trauma and the operation, there had been an interval of 3 months or longer in all patients. Patients were followed up for 3 months after the procedure to assess gripping strength and self-sufficiency (feeding, personal hygiene, dressing, and manual dexterity). FINDINGS: 15 Krukenberg procedures were done on 11 patients: eight men and three women (mean age 42 years). Three had single hand amputation and eight had double hand amputation. In only two patients had sufficient time passed for the stumps to heal. Of ten patients who were followed up at 3 months, all could eat and drink by themselves. The simple dressing test was passed by all patients and 75% of the patients had recovered some dexterity. INTERPRETATION: The Krukenberg procedure is a surgical option to achieve some manual dexterity in double hand amputees, where resources for sophisticated hand prostheses are lacking.

Activities of Daily Living↗

PubMed2000

Experience and visual perception in resident acquisition of laparoscopic skills.

Assess the role of experience and visual perception (VP) in resident acquisition of laparoscopic surgical skills (LSS).Thrity-nine residents (20 PGY-1s tested just before starting residency; 19 PGY 3+) completed an LSS course, including examination of course-specific knowledge before and after didactic tutorials, 10 trials of 3 dexterity drills and suturing, and 3 standardized VP tests.Mean speed increased significantly (p < 0.001) across trials for all dexterity drills and suturing. Senior residents performed suturing trials 1 to 4 significantly faster (p < 0.05) than did PGY 1's (M +/- SD averaged across trials 1 to 4: 166.5 +/- 59.9 vs 252.3 +/- 108.2 seconds, p < 0.01). Group differences on later trials were progressively smaller and nonsignificant, as were all group differences on dexterity drills. Significant correlations between VP and speed on drills ranged from (r = -0.41, p < 0.01) to (r = -0.71, p < 0.001). Visual perception did not correlate significantly with suturing speed; neither pretest nor posttest scores correlated significantly with drill or suturing speeds.Residents at all levels can significantly increase LSS performance speed to comparable levels during a brief intensive skills course. Proficiency in specific aspects of VP is directly associated with performance speed on dexterity drills, shown in previous studies to be fundamental in the development of intracorporeal suturing skill. (Curr Surg 57:368-372. Copyright 2000 by the Association of Program Directors in Surgery.)

Journal Article↗

PubMed2002

Donor/acceptor interactions in systematically modified Ru(II)-Os(II) oligonucleotides.

Donor/acceptor (D/A) interactions are studied in a series of doubly modified 19-mer DNA duplexes. An ethynyl-linked Ru(II) donor nucleoside is maintained at the 5' terminus of each duplex, while an ethynyl-linked Os(II) nucleoside, placed on the complementary strands, is systematically moved toward the other terminus in three base pair increments. The steady-state Ru(II)-based luminescence quenching decreases from 90% at the shortest separation of 16 A (3 base pairs) to approximately 11% at the largest separation of 61 A (18 base pairs). Time-resolved experiments show a similar trend for the Ru(II) excited-state lifetime, and the decrease in the averaged excited-state lifetime for each duplex is linearly correlated with the fraction quenched obtained by steady-state measurements. Analysis according to the Förster dipole-dipole energy transfer mechanism shows a reasonable agreement. Deviation from idealized behavior is primarily attributed to uncertainty in the orientation factor, kappa(2). Analyzing D/A interactions in an analogous series of doubly modified oligonucleotides, where the ethynyl-linked Ru(II) center is replaced with a saturated two-carbon linked complex, yields an excellent correlation with the Förster mechanism. As this simple change partially relaxes the rigid geometry of the donor chromophore, these results suggest that the deviation from idealized Förster behavior observed for the duplexes containing the rigidly held Ru(II) center originates, at least partially, from ambiguities in the orientation factor. Surprisingly, analyzing both quenching data sets according to the Dexter mechanism also shows an excellent correlation. Although this can be interpreted as strong evidence for a Dexter triplet energy transfer mechanism, it does not imply that this electron exchange mechanism is operative in these D/A duplexes. Rather, it suggests that systems that transfer energy via the Förster mechanism can under certain circumstances exhibit Dexter-like "behavior", thus illustrating the danger of imposing a single physical model to describe D/A interactions in such complex systems. While we conclude that the Förster dipole-dipole energy transfer mechanism is the dominant pathway for D/A interactions in these modified oligonucleotides, a minor contribution from the Dexter electron exchange mechanism at short distances is likely. This complex behavior distinguishes DNA-bridged Ru(II)/Os(II) dyads from their corresponding low molecular-weight and covalently attached counterparts.

DNA↗

PubMed1999

The EndoHand: comparison with standard laparoscopic instrumentation.

Laparoscopic instrumentation is constantly being refined in an attempt to achieve the proficiency, flexibility, and tactile feedback that would be available if the human hand were small enough to be used in laparoscopic surgery. The EndoHand (DAUM GmbH, Schwerin, Germany) is a novel laparoscopic three-fingered hand developed as an advancement over standard laparoscopic tools. Grasping and manipulation ability, dexterity, and tactile feedback were compared with those of current laparoscopic instrumentation. Experiments included measurement of achievable angles of approach to a fixed point behind a 2-cm-tall obstruction, completion time and error rates during a pelvic trainer dexterity task, and tactile feedback using a device invented to simulate tissue resistance. Subjectively, the EndoHand was able to pick up a range of objects similar to those graspable by a Babcock clamp. More complex types of manipulation were possible with the EndoHand because of its wrist joint. The range of approach angles to the fixed point was 35 degrees to 90 degrees with the EndoHand and 70 degrees to 90 degrees with the straight instruments. The dexterity of the EndoHand was significantly less than that of the other two instruments, as measured by time (P = 0.0002) and errors (P = 0.02). Standard instruments were also more accurate in the tactile feedback trials (P = 0.02). The EndoHand is a prototype of a unique new generation of laparoscopic instruments. Although it falls short in both dexterity and tactile feedback, significant promise is shown in its ability to perform sophisticated manipulation of objects and its flexibility to work at a larger range of angles to the target tissue. The EndoHand may be most useful on the nondominant hand of the surgeon to assist with positioning and holding tissue in a specific orientation. Clinical trials will determine its eventual role in laparoscopic surgery.

Confidence Intervals↗

PubMed1996

Spasticity and muscle contracture following stroke.

It has become increasingly recognized that the major functional deficits following brain damage are largely due to "negative' features such as weakness and loss of dexterity rather than spasticity. A variety of studies suggest that spasticity is a distinct problem and separate from the loss of dexterity, but that it may be implicated in the formation of muscle contracture and even in the recovery of strength. In order to address these issues, we examined the relationship between spasticity, contracture, strength and dexterity in the affected upper limb following stroke. Spasticity was measured both as increased tonic stretch reflexes and increased resistance to passive stretch (hypertonia). Twenty-four patients were recruited non-selectively from three rehabilitation units within 13 months of their stroke. Few patients exhibited increased tonic reflexes but half were found to have muscle contracture, the earliest at 2 months following stroke. Hypertonia was associated with contracture but not with reflex hyperexcitability. Increased tonic stretch reflexes were observed only in a subgroup of those with contracture and where present could usually be elicited only at the end of muscle range. This findings suggests that instead of spasticity causing contracture, contracture may actually potentiate spasticity in some patients. However, the majority of patients with contracture did not have increased tonic stretch reflexes. In addition, we found no relationship between spasticity and either weakness or loss of dexterity. Therefore, while hypertonia remains an important problem following cerebral lesions, it would appear that the amount of attention directed to reflex hyperexcitability associated with spasticity is out of proportion with its effects. Consequently, hypertonia needs to be clearly distinguished from reflex hyperexcitability in patients with spasticity.

Adult↗

PubMed1999

Impaired grip-lift synergy in children with unilateral brain lesions.

Children with spastic hemiplegia have impaired dexterity in the affected extremity. The purpose of the present study was to investigate whether the force co-ordination pattern during precision grip in 13 children between 4 and 10 years of age with predominant unilateral brain lesions is related to manual dexterity and to the location and size of the brain lesion. The force co-ordination pattern was investigated by means of a specially designed object that monitored the isometric fingertip forces applied to the contact surfaces during precision grip. Hand function was measured by means of neurological examination, functional hand-grips and dexterity. Brain lesions were identified by series of ultrasound and MRI scans. Normally, the fingertip forces are applied to the object in the initial phase of the lift in an invariant force co-ordination pattern (i.e. grip-lift synergy), in which the grip and load forces are initiated simultaneously and increase in parallel with unimodal force rate trajectories. A majority of children with unilateral brain lesions had not developed the force co-ordination pattern typical for their age, but produced an immature or a pathological pattern. The developmental level of the grip-lift synergy was determined and quantified according to criteria derived from earlier studies on normally developed children. There was a clear relationship between the developmental level of the grip-lift synergy and impaired dexterity, indicating that proper development of the force co-ordination pattern is important for skilled hand function. The grip-lift synergy correlated with the total extent of lesions in the contralateral cortex and white matter and with lesions in the thalamus/basal ganglia, while no correlation was found for isolated cortical lesions. The results suggest that the neural circuits involved in the control of the precision grip are organized in a parallel and distributed system in the hemispheres, and that the basal ganglia are important during the formation of these circuits. Perinatal lesions in specific cortical motor areas may be compensated for by circuits elsewhere in the grip-lift motor system, while large lesions exclude this possibility.

Brain↗

PubMed1984

An evaluation of possible interactions between ethanol and trazodone or amitriptyline.

The pharmacodynamic effects of single doses of trazodone (100 mg), amitriptyline (50 mg) or placebo either alone or with ethanol (0.5 ml/kg) were investigated in six healthy volunteers in a double-blind crossover study. Plasma concentrations of the drugs and ethanol were also measured. Pharmacodynamic tests were critical flicker fusion frequency threshold (CFF), choice reaction time (CRT), manual dexterity, a digit span test and visual analogue scales. Blood ethanol concentrations were not influenced by the co-administration of either antidepressant. tmax for trazodone was prolonged by ethanol but the other pharmacokinetic parameters for trazodone and amitriptyline were not influenced by ethanol. Trazodone and amitriptyline caused the expected profound depressant effects on CFF, CRT, manual dexterity and on the rating scales for drowsiness, 'clear-headedness', aggression and disinhibition. Ethanol alone impaired manual dexterity, increased drowsiness, reduced 'clear headedness' and also tended to reduce feelings of aggression. In combination with either trazodone or amitriptyline, ethanol caused little additional effect except in the case of manual dexterity which was further impaired. This result may reflect the profound effects of the antidepressants alone and does not suggest that it is safe for patients receiving antidepressant medication to take ethanolic drinks.

Adult↗

PubMed2005

Factors related to oral hygiene in persons with scleroderma.

OBJECTIVES: The purpose of this study was to assess potential risk factors for the development of poor oral hygiene and increased dental caries in individuals with scleroderma. METHODS: Twenty-two subjects with scleroderma participated in this study. All subjects were examined with the Patient Hygiene Performance (PHP) Index, which assesses the extent of plaque and debris over a tooth surface. In addition, oral aperature, xerostomia and dominant upper extremity strength, motion, skin thickness, and dexterity were measured. RESULTS: None of the subjects had good or excellent hygiene. Fifteen subjects had fair oral hygiene and seven subjects had poor oral hygiene as measured by the PHP Index. Significant differences were seen between these two groups for oral aperture, percentage of teeth with caries, skin thickness, dexterity and finger flexion. Dexterity and joint motion correlated significantly with the number of decayed surfaces and number of caries. Oral aperture correlated with the PHP Index and the number of dental caries. CONCLUSIONS: Subjects with poor oral hygiene required more time to complete manual dexterity task and had decreased hand strength and joint motion. Moreover, these same subjects had more contractures, scars, ulcers, and higher skin scores (more disease activity) than subjects in the fair hygiene group. In addition to frequent dental exam and routine cleaning, dental personnel may want to consider exercises to increase oral aperature and investigate toothbrush and dental floss selection used by persons with scleroderma.

Dental Caries↗

PubMed2001

Relationship between body heat content and finger temperature during cold exposure.

The purpose of the present experiment was to examine the relationship between rate of body heat storage (S), change in body heat content (DeltaH(b)), extremity temperatures, and finger dexterity. S, DeltaH(b), finger skin temperature (T(fing)), toe skin temperature, finger dexterity, and rectal temperature were measured during active torso heating while the subjects sat in a chair and were exposed to -25 degrees C air. S and DeltaH(b) were measured using partitional calorimetry, rather than thermometry, which was used in the majority of previous studies. Eight men were exposed to four conditions in which the clothing covering the body or the level of torso heating was modified. After 3 h, T(fing) was 34.9 +/- 0.4, 31.2 +/- 1.2, 18.3 +/- 3.1, and 12.1 +/- 0.5 degrees C for the four conditions, whereas finger dexterity decreased by 0, 0, 26, and 39%, respectively. In contrast to some past studies, extremity comfort can be maintained, despite S that is slightly negative. This study also found a direct linear relationship between DeltaH(b) and T(fing) and toe skin temperature at a negative DeltaH(b). In addition, DeltaH(b) was a better indicator of the relative changes in extremity temperatures and finger dexterity over time than S.

Adult↗

PubMed1986

Evaluation of possible interactions between ethanol and trazodone or amitriptyline.

The pharmacodynamic effects of single doses of trazodone (100 mg), amitriptyline (50 mg) or placebo either alone or with ethanol (0.5 ml/kg) were investigated in 6 healthy volunteers in a double-blind crossover study. Plasma concentrations of the drugs and ethanol were also measured. Pharmacodynamic tests were critical flicker fusion frequency threshold (CFF), choice reaction time (CRT), manual dexterity, a digit span test and visual analogue scales. Blood ethanol concentrations were not influenced by the co-administration of either antidepressant. tmax for trazodone was prolonged by ethanol but the other pharmacokinetic parameters for trazodone and amitriptyline were not influenced by ethanol. Trazodone and amitriptyline caused the expected profound depressant effects on CFF, CRT, manual dexterity and on the rating scales for drowsiness, 'clearheadedness', aggression and disinhibition. Ethanol alone impaired manual dexterity, increased drowsiness, reduced 'clearheadedness' and also tended to reduce feelings of aggression. In combination with either trazodone or amitriptyline, ethanol caused little additional effect except in the case of manual dexterity, which was further impaired. This result may reflect the profound effects of the antidepressants alone and does not suggest that it is safe for patients receiving antidepressant medication to take ethanolic drinks.

Adult↗

PubMed2000

Accuracy of physical and occupational therapists' early predictions of recovery after severe middle cerebral artery stroke.

INTRODUCTION: The ability of physical therapists (PTs) and occupational therapists (OTs) to predict level of outcome accurately was investigated prospectively in 91 severely disabled stroke patients with a first-ever middle cerebral artery (MCA) stroke. METHODS: Within the second and fifth week after stroke onset, 364 predictions were made by 59 PTs and 47 OTs about walking ability, dexterity, activities of daily living (ADL), need for additional care in ADL, time required to achieve independent walking ability and maximal level of ADL, and destination of discharge at six months after stroke. The functional recovery patterns of stroke patients were assessed by an independent observer. The accuracy of the therapists' predictions was compared with that of derived prediction models. In addition, the influence of characteristics of patients and therapists on the accuracy of the predictions was investigated. RESULTS: Compared to observed outcomes at six months after stroke, therapists' lowest accuracies of prediction were found for the moment at which maximal ADL score was achieved (rs = 0.07; p = NS), and highest accuracy was for level of dexterity of the hemiplegic arm (rs = 0.78; p <0.01). Therapists' predictions of functional outcome at six months tended to be too pessimistic. No significant differences were observed for dexterity and walking ability when the predictions by PTs and OTs were compared with those of regression models, whereas significant differences were found for the accuracies of OTs' and PTs' first prediction of destination of discharge and second predictions of outcome in ADL and need for additional care in ADL. No significant differences were found between the accuracy of PTs' and OTs' predictions, and their ability to predict functional outcome was not significantly influenced by the characteristics of patient and therapists. CONCLUSIONS: At two and five weeks after stroke, OTs and PTs can accurately predict level of walking ability and dexterity at six months. The prediction of time required for achieving maximal level of recovery, destination of discharge, outcome of ADL as well as need for additional care in ADL leaves room for improvement.

Activities of Daily Living↗

PubMed1992

Biologic significance of constitutive and subliminal growth factor production by bone marrow stroma.

The "stromal" or adherent cells of long-term murine Dexter explant bone marrow cultures provide the best in vitro model of the bone marrow microenvironment. Colony-stimulating factor-1 (CSF-1) is produced constitutively by these cells and is easily detected, but most investigators have not found constitutive production of the other hemolymphopoietic cytokines. We have previously reported the detection of granulocyte-macrophage-CSF (GM-CSF) in murine stromal cultures and its induction by the lectin Pokeweed mitogen. The present studies analyzing stromal cytokine messenger RNA (mRNA) production by standard Northern blot analysis show constitutive production of mRNAs for CSF-1, GM-CSF, granulocyte-CSF (G-CSF), c-kit ligand (KL), and interleukin-6 (IL-6), but not IL-3, IL-4, or IL-5 by 3-week irradiated or nonirradiated murine Dexter stromal cells. Exposure of stromal cells to Pokeweed mitogen or IL-1 16 hours before RNA harvest induces the messages for GM-CSF, G-CSF, KL, and IL-6, but not IL-3, IL-4, IL-5, or CSF-1. Polymerase chain reaction amplification of cDNA made with reverse transcriptase from stromal RNA using two separate sets of IL-3-specific primers shows the presence of IL-3 message in irradiated stromal cells, which is only detectable with this more sensitive technique. The factor-dependent cell lines FDC-P1 and 32D are supported by the stromal cells without the addition of exogenous growth factors, demonstrating a cytokine activity in these cultures that is inhibited by the addition of anti-IL-3 or anti-GM-CSF antibodies. These data indicate that murine Dexter stromal cells constitutively produce CSF-1, GM-CSF, G-CSF, IL-6, KL, and IL-3. This growth factor production could explain the support of granulocyte, macrophage, and megakaryocyte production and stem cell maintenance in Dexter-type long-term murine bone marrow cultures.

Animals↗

PubMed2006

Chronic odontogenic maxillary sinusitis.

The aim of the present study was to estimate average age of the patients in both sexes treated for MS, distribution by sex, amount of dexter and sinister MS with and without the fistulas into the maxillary sinus, with and without the foreign-bodies, length of stay in the Department of Maxillofacial Surgery at Kaunas Hospital of University of Medicine during the period from 1999 till 2004. The retrospective data analysis of the patients' treated from chronic MS was made. 346 patients (213 females and 133 males) were treated for chronic MS. 55 cases of chronic dexter MS with a fistula into maxillary sinus, 98 cases of chronic dexter MS without a fistula, 45 cases of chronic sinister MS with a fistula, 112 cases chronic sinister MS without a fistula, 16 cases of foreign-bodies in dexter maxillary sinus, 20 cases of foreign-bodies in sinister maxillary sinus have been detected. The main age of the female was 46.6+/-15.0, the main age of the men was 42.1+/-14.4. Statictically significant difference in the age difference of the women and the men was found (p=0.0024). It was determined, that females diagnosed and treated with chronic MS were 1.6 times more than males during the period from 1999 till 2004 in Kaunas Hospital of University of Medicine. Females treated for chronic MS were 4.5 years older than males.

Adolescent↗

PubMed1981

Evaluation of monolayer, liquid, gelfoam sponge and artificial capillary culture systems for the study of hematopoiesis.

This study evaluated the usefulness of a matrix culture system, the artificial capillary culture system, for the growth of hematopoietic cells, the maintenance of CFUS and the collection of GM-CSF. The system was compared to monolayer, gelfoam sponge and Dexter liquid cultures. Monolayer cultures of adherent lymphohematopoietic stromal cells were prepared from bone fragments, whole bone marrow (Dexter system), spleen, fetal liver and thymus preparations. Morphologically, all the adherent cell populations were similar and tended to accumulate macrophages. Despite these morphological similarities, the ability of bone marrow adherent cell monolayers to maintain CFUS early in the culture period was significantly greater than adherent cells from other sources. Low but significant levels of GM-CSF were detected by bioassay in the supernatants of all but bone marrow adherent cell cultures. However, adherent cells selected from whole marrow cultures by differential trypsinization contained bioassayable levels of CSF suggesting that Dexter cultures contain a supernatant inhibitor/inactivator of GM-CSF. The greatest capability of the artificial capillary culture system was to increase about 500-fold over monolayers the GM-CSF collected from bone fragment derived stromal cells. Unfortunately, CFUS maintenance was poor, the system was more expensive than monolayer cultures and in our hands, suffered many mechanical failures usually resulting in loss of sterility. Histological evaluation suggested there was inadequate matrix for optimal attachment and growth of lymphohematopoietic stromal cells. Even so this system has a much greater potential for development than gelfoam sponges. Overall, Dexter cultures appear to be the most useful system currently available for the study of hematopoiesis and hematopoietic regulatory interactions.

Animals↗

PubMed1995

The hand in the cold, performance and risk.

When a person is exposed to cold and his metabolic rate is insufficient to maintain a positive or neutral heat balance, the body will cool down. For the extremities this will result in a drastic reduction of blood flow, resulting in a so called "physiological amputation" with extremity cooling towards ambient temperature. The dexterity decrease observed with cold extremities is most likely caused by cooling of muscles and joints, and not by effects on receptors, nerve conduction or central effects. It is shown, that dexterity decreases can be described in terms of wind chill equivalent temperature and exposure time for a certain clothing and work configuration. Further, the risk of skin freezing and reduced dexterity due to touching cold objects can be described using the contact coefficient of the respective material and the contact time. This risk is modulated by metabolic rate and hand protection (gloves). Gloves drastically reduce cooling speed and freezing risk, but they also cause increased risks due to reduced dexterity due to glove thickness. For a general description of performance and risk of hand cold exposure in relation to climate and exposure time more data are needed.

Cold Temperature↗

PubMed1996

Regional brain tissue composition in children with hydrocephalus. Relationships with cognitive development.

OBJECTIVE: To determine whether children with shunted hydrocephalus show variations in regional brain tissue composition that relate to cognitive functions. DESIGN: Nonequivalent control group. PATIENTS AND METHODS: Magnetic resonance imaging (MRI) and cognitive skills assessments were obtained on 28 children, 6 to 9 years of age, with shunted hydrocephalus and 13 normal control subjects comparable in age, gender, ethnicity, and socioeconomic status. Three consecutive MRI slices below the vertex were segmented using a fuzzy clustering algorithm to separate pixels into gray matter, white matter, and cerebrospinal fluid (CSF) in quadrants representing left and right anterior and posterior brain regions. The cognitive skills assessments included the Wechsler Intelligence Scale for Children-Revised verbal and performance IQ scores, neuropsychological composites of language and visuospatial skills, a measure of visuomotor dexterity, and 2 measures of problem-solving abilities. The MRI data were analyzed in a group x tissue x hemisphere x region analysis of variance. Spearman rho correlations were computed within the hydrocephalus group between the MRI and cognitive measures. RESULTS: Children with hydrocephalus showed reductions in overall gray matter percentages and corresponding increased CSF percentages that were more pronounced in posterior than anterior regions of both hemispheres. White matter percentages were reduced in children with hydrocephalus only in the left posterior quadrant. Correlations of posterior, but not anterior, CSF and gray matter percentages were significant with verbal and performance IQ scores and language, visuospatial, and visuomotor dexterity skills, but not with problem-solving abilities. Children with hydrocephalus who had proportionately greater posterior than anterior CSF percentages had significantly poorer visuomotor dexterity and visuospatial skills than did hydrocephalic children with proportionate CSF percentages. CONCLUSION: Regional variations in brain tissue composition in children with shunted hydrocephalus correlate with a variety of cognitive and visuomotor functions.

Agenesis of Corpus Callosum↗

PubMed1996

Results of interfascicular nerve grafting for radial nerve lesions.

During the 10 year interval 1979-1989, 20 patients underwent nerve grafting of a radial nerve lesion, 13 high radial and 7 posterior interosseous. Average follow-up was 38 months (range 12 months-10 years). Overall 72% of patients achieved a Highet Scale rating of M3 or better function and 44% M4 or better recovery. Age of the patient and length of the nerve graft did not seem to influence outcome. Time from initial injury to nerve grafting did affect outcome, with 85% of patients grafted within 6 months obtaining M3 or better recovery. No patient grafted 12 months after injury recovered any useful function. Lesions of the posterior interosseous nerve had a consistently superior recovery. Power grip strength in the affected hand of patients averaged 60% of the unaffected hand while key pinch averaged 74%. There was good correlation between the Highet Scale rating of recovery and the ultimate power grip or key pinch strength obtained. Hand dexterity, as assessed by the turning and displacing tests of the Minnesota Rate of Manipulation Test, displayed a wide range of scores in both affected and unaffected hands. Nevertheless, a relative score derived from the results obtained in the displacing test did show correlation with the Highet Scale rating. All patients with M4 or better recovery obtained relative scores for the affected hand that were in the middle of the range of scores considered an average performance for a normal population. Patients who achieved M4 or better nerve recovery following radial nerve grafting also obtained a functional hand as evidenced by the results of grip, key pinch strength, and hand dexterity testing. Lesser degrees of recovery were accompanied by poorer strength and dexterity ratings reflecting inferior function.

Adult↗