The impact of complex facial surgery provided on a short-term surgical mission.

The long-term consequences of performing facial surgery on patients living in rural Ethiopia are largely unknown. A review of 36 patients who had been treated on a short-term surgical mission (STSM) in the previous 2 years was conducted to evaluate the outcomes of the surgical interventions performed. There was a significant reduction in social isolation following a surgical intervention. Improvements in postoperative self-reported changes were found for facial appearance, facial function, and quality of life. Positive outcomes can be achieved when surgical treatment is performed on a STSM.

The governance of overseas surgical collaborations - BFIRST/BSSH.

Clinical governance is the structured approach to maintaining and improving the quality of patient care and is a vital part of global surgery. BFIRST and BSSH closely collaborate with local doctors on a number of overseas projects, seeking to strengthen and develop local knowledge and skills, aiming for an independent local practice in reconstructive and upper limb surgery. Thoughts on essential requirements, improvements and pitfalls in the ethical approach to global collaboratives are presented.

[Rare combination injury of traumatic spondylolisthesis of the lumbosacral junction and Malgaigne's C3 fracture of the pelvis : Lessons learned]. / Seltene Kombinationsverletzung einer traumatischen Spondylolisthese des lumbosakralen Übergangs und C3-Beckenfraktur (Malgaigne-Verletzung) : "Lessons learned".

This article reports on the case of a rare combination injury of a C3 pelvic ring fracture (Malgaigne's fracture) and simultaneous unstable traumatic spondylolisthesis (Meyerding grade 2) of the lumbosacral spine. The patient had pronounced neurological deficits of the lower extremities and tearing of the thecal sac. The selected primary and secondary surgical treatment algorithm of the polytraumatized patient as well as the course are described and critically discussed on the basis of the sparsely available literature.

Long-term outcomes associated with short-term surgical missions treating complex head and neck disfigurement in Ethiopia: A retrospective cohort study.

BACKGROUND: Long-term follow-up after short-term reconstructive missions is challenging, often due to financial constraints, remote geography and lack of post-operative communication with patients. The aim of this study was to conduct long-term follow-up of patients who have undergone surgery for complex facial disfigurement in Ethiopia. METHODS: A retrospective cohort study was conducted in Ethiopia over a 2-week period between February and March 2017. All patients who were previously operated on by the charity Project Harar were eligible. Data were collected from semi-structured interviews and clinical examinations. RESULTS: Seventy patients (41 males: 29 females) were included in this study. This equates to a follow-up rate of 20% (70/350) of all patients operated on by the charity since 2008. Mean patient age was 26.8 years (range, 3-61 years). The most common pathologies were noma (24%), ameloblastoma (16%) and trauma (11%). The mean follow-up time after final surgery was 47 months (range, 12-180) with an average of 1.3 (range, 1-6) operations per patient. Long-term complications were reported by 30% of patients, with chronic fistula (n = 6) and chronic infection (n = 3) the most common. Following surgery, stigma experienced by patients decreased from 92% to 3%. CONCLUSIONS: This study demonstrates that complex head and neck reconstruction can be safely undertaken in resource-limited settings with improvements in stigma experienced and quality of life for patients. However, despite a decade of experience and refinements, early and late complications do occur, and this should be factored into pre-mission planning and careful follow-up. New, cost-neutral follow-up protocols are being developed.

Facial injuries following hyena attack in rural eastern Ethiopia.

Hyenas are effective hunters and will consider humans as potential prey if the need and opportunity arise. This study describes the circumstances of hyena attacks, the patterns of injuries sustained, and reconstruction in a resource-poor setting. As part of a charitable surgical mission to Ethiopia in 2012, 45 patients with facial deformities were reviewed, of whom four were victims of hyena attacks. A semi-structured interview was performed to ascertain the circumstances of the attack and the subsequent consequences. The age of the victims at the time of attack varied from 5 to 50 years. The attacks occurred when the victims were alone and vulnerable and took place in outdoor open spaces, during the evening or at night. The initial lunge was made to the facial area; if the jaws closed on the facial bones they were crushed, but in all cases the soft tissues were grasped and torn from the underlying bone. Reconstruction was dictated by the extent of soft tissue loss but could normally be obtained by use of local or regional flaps. Hyenas have been shown to attack humans in a predictable way and cause injuries that typically involve the soft tissues of the face.

Surgical mission planning in the developing world.

Surgical missions to the developing world have been criticized for their lack of outcome analysis. Reported studies indicate a high rate of postoperative complications. An integrated pathway developed for surgical missions and a report of its performance in action is presented herein. Patients were optimized for surgery by a medical team from the UK for a minimum of 14 days preoperatively. They were then transferred to hospital for surgery and returned when stable. At the completion of the mission a junior doctor remained behind for 3 weeks to chart the patients' progress. Thirty case patients were treated over a 2-week period. The complication rate at 3 weeks postoperatively was 7/30. Twenty-two operations were classified as complex (over 1h with more than one flap) and eight as simple (under 1h with minimal flaps). Of those undergoing the simple operations, 2/8 encountered complications at an average of 5 days postoperatively (range 3-7 days). Many medical teams depart in an elevated atmosphere of accomplishment, which without an outcome analysis gives a false impression of their positive impact. Outcome analysis is essential to honestly appraise the effect of surgical missions.

Complex traits analysis of chicken growth using targeted genetical genomics.

Dissecting the genetic control of complex trait variation remains very challenging, despite many advances in technology. The aim of this study was to use a major growth quantitative trait locus (QTL) in chickens mapped to chromosome 4 as a model for a targeted approach to dissect the QTL. We applied a variant of the genetical genomics approach to investigate genome-wide gene expression differences between two contrasting genotypes of a marked QTL. This targeted approach allows the direct quantification of the link between the genotypes and the genetic responses, thus narrowing the QTL-phenotype gap using fewer samples (i.e. microarrays) compared with the genome-wide genetical genomics studies. Four differentially expressed genes were localized under the region of the QTL. One of these genes is a potential positional candidate gene (AADAT) that affects lysine and tryptophan metabolism and has alternative splicing variants between the two genotypes. In addition, the lysine and glycolysis metabolism pathways were significantly enriched for differentially expressed genes across the genome. The targeted approach provided a complementary route to fine mapping of QTL by characterizing the local and the global downstream effects of the QTL and thus generating further hypotheses about the action of that QTL.

[Algorithm for treatment of deep spinal infections and spondylodiscitis with in situ instrumentation]. / Algorithmus zur Behandlung tiefer Wirbelsäuleninfektionen und der Spondylodiszitis bei einliegender Instrumentierung.

Due to a significant increase in spinal interventions and in particular spinal fusion procedures, also in elderly and immunocompromised patients, spinal surgeons are increasingly confronted with deep wound infections and/or spondylodiscitis with in situ instrumentation. This occasionally life-threatening complication can be a challenge for even the most experienced physician, not only in the initial diagnosis but also when determining the operative treatment strategy. It is not uncommon that patients must undergo several operations before a deep infection is finally under control. The aim of this article is to suggest an algorithm for the diagnostics and management of this very troubling complication.

Investigation into the influence of a high fat diet on antipsychotic-induced weight gain in female rats.

Atypical antipsychotic drug therapy may result in substantial weight gain, increased adiposity and the promotion of metabolic abnormalities. The mechanism(s) which underlie such effects remain unclear. Previous studies in our laboratory have demonstrated significant weight gain in female rats maintained on a standard laboratory diet after sub-chronic administration of olanzapine and risperidone, but not ziprasidone. The aim of this paper is to investigate the effect of antipsychotic drugs on body weight, ingestive behaviour and adiposity in female rats with access to a high fat diet. Adult female rats given free access to a high fat diet received either olanzapine (2 mg/kg), risperidone (0.5 mg/kg), ziprasidone (2.5 mg/kg) or vehicle for 28 days. Body weight, food and water intake in addition to intra-abdominal fat deposition were assessed. Olanzapine initially increased body weight but by the end of the study olanzapine animals appeared to have lost weight compared to the vehicle-treated group. Olanzapine-induced reductions in body weight were accompanied by a significant hypophagia during weeks 3 and 4. Risperidone increased body weight during week 1 only and reduced intake of a high fat diet during weeks 3 and 4. Ziprasidone was without effect on indices of body weight and ingestive behaviour. There were no effects of antipsychotic drugs on intra-abdominal fat deposition. Access to a diet high in fat attenuated weight gain induced by olanzapine and risperidone in female rats.

The distinct effects of subchronic antipsychotic drug treatment on macronutrient selection, body weight, adiposity, and metabolism in female rats.

INTRODUCTION: Treatment with some antipsychotic drugs may result in excessive body weight gain which can have detrimental effects on patient compliance, morbidity and mortality. The aim of the present study was to investigate the effect of atypical antipsychotic drugs on dietary macronutrient selection, body weight, body composition and biochemical parameters related to obesity in female rats. MATERIALS AND METHODS: Forty pair-housed, adult female hooded-Lister rats (250 +/- 5 g) were habituated to three diets containing principally protein, fat, or carbohydrate in a home cage self-selection paradigm. Olanzapine (2 mg/kg), risperidone (0.5 mg/kg), ziprasidone (2.5 mg/kg), or vehicle was injected intraperitoneally once daily for 22 days; food selection, water intake, and body weight were recorded daily, while body composition and plasma hormones (insulin, glucose, nonesterified free fatty acid, total cholesterol, glycerol, triacylglycerol, leptin, and prolactin) were analyzed at the end of the study. RESULTS: Only olanzapine significantly increased body weight and food intake. Macronutrient selection was significantly altered after olanzapine and risperidone treatment (increased protein and decreased fat preference). Only olanzapine increased carcass fat content. Locomotor activity was significantly reduced in all treatment groups. Both olanzapine and risperidone significantly increased plasma prolactin. Olanzapine was without effect on any other biochemical parameter measured. Ziprasidone significantly reduced plasma leptin and nonsignificantly reduced NEFA, while risperidone significantly reduced fasting plasma glucose. CONCLUSION: This study supports our previous work demonstrating weight gain and increased feeding behavior induced by olanzapine and could have important implications for enhancing our understanding of the mechanisms by which olanzapine and other atypical antipsychotics induce weight gain in the clinic.

Effects of sub-chronic antipsychotic drug treatment on body weight and reproductive function in juvenile female rats.

RATIONALE: Weight gain caused by some antipsychotics is not only confined to adults but can also adversely affect both children and adolescents. Indeed, olanzapine and risperidone have been associated with extreme weight gain in adolescents even greater than that reported in adults. We have recently shown substantial weight gain in adult female rats following treatment with olanzapine and risperidone but not ziprasidone. OBJECTIVES: The aim of the present study was to compare the effects of several antipsychotics on weight gain and reproductive function in juvenile (aged 7 weeks) female hooded Lister rats. METHODS: Olanzapine (4 mg/kg), risperidone (0.5 mg/kg), ziprasidone (2.5 mg/kg), sulpiride (10 mg/kg), haloperidol (0.5 mg/kg) or vehicle was administered i.p. once per day for 21 days. Body weight, food and water intake were measured daily, in addition to the determination of stage of the oestrous cycle. RESULTS: Sub-chronic administration of olanzapine, risperidone, sulpiride and haloperidol, but not ziprasidone, significantly increased body weight compared to vehicle-treated animals during weeks 1-3. Sulpiride significantly increased food and water intake. Significantly increased percentage intra-abdominal fat weight was observed in olanzapine, risperidone, sulpiride and haloperidol, but not ziprasidone-treated animals. Marked disruption of the oestrous cycle was observed in all but the ziprasidone-treated group, which continued to have regular 4-day oestrous cycles. CONCLUSIONS: Weight gain observed in these juvenile animals was 1.5-2 times greater than that previously observed in adult rats. These findings have important implications for the use of antipsychotics in children and adolescent patients.

Investigation into the effects of the novel antipsychotic ziprasidone on weight gain and reproductive function in female rats.

Weight gain and sexual dysfunction are serious side effects of certain antipsychotic drugs. Ziprasidone, a novel antipsychotic with a unique receptor binding profile, is reported to have a low propensity for such side effects. Previous results from this laboratory have demonstrated substantial weight gain following sub-chronic treatment with olanzapine and risperidone. Risperidone induced weight gain and markedly impaired reproductive function while olanzapine induced weight gain, without affecting reproductive function. The aim of this study was to investigate effects of ziprasidone on weight gain and reproductive function in female rats. Ziprasidone (1 and 2.5 mg/kg i.p.) or vehicle was administered once daily for 28 days and body weight, food and water intake measured, in addition to histological examination of vaginal lavage to determine the stage of the oestrous cycle. On day 28, the rats were sacrificed and the uterine weights recorded, intra-abdominal fat weight and plasma prolactin levels measured. Ziprasidone failed to induce significant weight gain during weeks 1-3, however, significant weight gain was observed on day 28 at 2.5 mg/kg (p < 0.05). Ziprasidone had no effect on food intake at any time point. A significant reduction in water intake (p < 0.05) was observed during the first week of treatment with 2.5 mg/kg ziprasidone. Ziprasidone had no effect on intra-abdominal fat weight, wet or dry uterine weight or plasma prolactin levels. All ziprasidone treated animals displayed a normal four-day oestrous cycle. This study is the first to report that ziprasidone is without effect on reproductive function or ingestive behaviour in the rat.

Effects of the classical antipsychotic haloperidol and atypical antipsychotic risperidone on weight gain, the oestrous cycle and uterine weight in female rats.

Antipsychotic drug-induced side effects of weight gain and sexual dysfunction have clinical significance adversely affecting both compliance and morbidity. This study evaluated the effects of haloperidol and the atypical antipsychotic risperidone (0.1-1.0 mg/kg) on weight gain, food and water intake, the oestrous cycle and uterine weight in female hooded Lister rats. Haloperidol and risperidone treated rats displayed marked weight gain, although only risperidone induced significant increases in food consumption over the 21-day period. Neither haloperidol nor risperidone influenced water consumption. Marked disruption of the oestrous cycle was observed in risperidone- and haloperidol-treated animals (0.5 and 1.0 mg/kg), which was supported by significantly reduced uterine weights. The findings presented here suggest that the weight gain and sexual dysfunction induced by antipsychotics may be modelled in rodents. This model may offer insight into the mechanisms involved in mediation of such side effects.

Effects of the atypical antipsychotic olanzapine on reproductive function and weight gain in female rats.

Sexual dysfunction is a major, although poorly understood, side-effect of treatment with antipsychotic drugs. We have recently show marked disruption of reproductive function and weight gain in female rats treated subchronically with risperidone and haloperidol. The aim of the present study was to examine further the potential relationship between reproductive dysfunction and weight gain in female rats treated with olanzapine. The effects of olanzapine on weight gain, food and water intake, intra-abdominal fat, the oestrous cycle and uterine weight were assessed in group-housed adult female hooded-Lister rats. Olanzapine (0.5-4.0 mg/kg i.p.) or vehicle was administered once daily for 21 days and body weight, food and water intake measured, with histological examination of vaginal lavage to determine the stage of the oestrous cycle. On day 22, animals were sacrificed and intra-abdominal fat, wet and dry uterine weights measured. Olanzapine induced significant weight gain with concomitant increases in food and water intake and intra-abdominal fat without an effect on the oestrous cycle, wet and dry uterine weights or plasma prolactin levels. These results confirm the ability of olanzapine to induce weight gain in female rats on unrestricted normal diet with a concomitant increase in food and water intake and increased intra-abdominal fat. These effects of olanzapine were produced in the absence of any apparent impairment in reproductive function, in contrast to the substantial disruption of oestrous and uterine atrophy previously shown in rats treated with risperidone and haloperidol.

[Comparison of internal fixation methods for the symphysis in multi-directional dynamic gait simulation]. / Vergleich interner Stabilisierungsverfahren für die Symphyse im multidirektionalen dynamischen Gangbedingungssimulator.

For the stabilization of the ruptured pubic symphysis, rigid forms of fixation such as plate osteosynthesis and flexible fixations such as wire loops or PDS banding have been recommended. All methods have only been tested by static unidirectional loading until failure of the system. By this experimental arrangement Ecke and Hofmann found comparable results for flexible and rigid methods of internal stabilization of the pubic symphysis. They preferred flexible methods to maintain mobility of the symphysis and to prevent symphyseal fusion. We tested dynamic compression plate osteosynthesis, reconstruction plate osteosynthesis, wire loops and PDS banding for internal fixation of injured pubic symphysis in a dynamic multidirectional experimental arrangement simulating gait conditions. The specimens were loaded with 85 N in vertical (y-) direction and 34 N in sagittal (z-) direction, which represent 50% of the forces acting at the pubic symphysis during walking and with a frequency of 1.5 Hz over 55,500 loads simulating the conditions over a 6-week mobilization period. Loading with 100% of the acting forces (corresponding to full weight bearing mobilization) led to early failure of the system. Our experimental analysis showed that neither wire loops nor PDS banding is able to stabilize the ruptured pubic symphysis, even immediately after fixation before loading. During the tests instability increased until failure of the system due to cutting of the bone or breaking of the wires or PDS banding. Success of plate osteosynthesis was dependent on the initial stability of the fixation. Overwinding of the screws, as in osteoporotic bone, lead to increasing loosening during repeated loading, whereas primary stable fixation of the screws was almost completely maintained during the test. In consequence, neither wire loops nor PDS banding should be used for stabilization of injured pubic symphysis if early mobilization with partial weight bearing is desired. Plate osteosynthesis (DC or reconstruction plate) tolerates early half weight bearing in patients with "open-book" injury only if safe screw fixation is guaranteed.

[Biomechanics of the pubic symphysis. Which forces lead to mobility of the symphysis in physiological conditions?]. / Zur Biomechanik der Symphyse. Welche Kräfte führen zur Mobilität der Symphyse unter physiologischen Bedingungen?

For estimation of the loads of fixation devices, physiological movements and acting forces at the symphysis pubis are examined. Experimentally, Walheim determined the movements of the pubic symphysis under physiological conditions (one-leg stance, walking): there is no effective mobility in the horizontal direction. During the one-leg stance he observed symphyseal mobility of up to 2.6 mm (Phi 1.2 mm) in the vertical direction and 1.3 mm (Phi 0.6 mm) in the sagittal direction. During walking he found symphyseal mobility of up to 2.2 mm (Phi 0.9 mm) in the vertical direction and 1.3 mm (Phi 0.6 mm) in the sagittal direction. Until now the forces leading to symphyseal mobility have not been estimated either experimentally or mathematically. In our experimental study we examined ten fresh cadaver anterior pelvic rings by means of a multidirectional force-mobility measurement. Maximal physiological movements, as determined by Walheim, were increasingly induced in ten equal steps, and the forces required were measured for every single step. Out of the resulting force-mobility curves for the ten cadaver specimens the mean force required (with standard deviation) was calculated for each of the ten measure points, separately for the vertical (y-) direction and sagittal (z-) direction. The values were graphically transferred, and a regression curve was created. This curve allows the acting force to be estimated for every movement of the pubic symphysis: During the one-leg stance the mean force to induce mean mobility is 169 N in vertical direction and 148 N in sagittal direction; for maximal mobility a force of 398 N in the vertical direction and 148 N in the sagittal direction is necessary. During walking, the force required to induce mean movement of the symphysis pubis is 120 N in the vertical direction and 68 N in the sagittal direction; for maximal mobility 333 N is required in the vertical direction and 136 N in the sagittal direction. For mobilization of patients with a symphyseal rupture (type Tile B 1) with partial weight-bearing, neutralization of the mean acting forces during the one-leg stance (169 N in the vertical direction, 68 N in the sagittal direction) must be achieved by an adequate fixation device. In cases where full weight bearing is desirable, such as in patients with limited compliance, stability can only be reached by neutralization of the maximal acting forces during walking (333 N in the vertical direction, 136 N in the sagittal direction).

[Pelvic fractures: epidemiology, therapy and long-term outcome. Overview of the multicenter study of the Pelvis Study Group]. / Beckenverletzungen: Epidemiologie, Therapie und Langzeitverlauf. Ubersicht über die multizentrische Studie der Arbeitsgruppe Becken.

Pelvic fractures are rare injuries (3-8%) when compared to fractures in other body regions. They are accompanied by high mortality (5-20%), and the survivors suffer from severe pain and pelvic-related handicaps. The German Pelvic Group (German Chapter of the AO-International & German Trauma Society) started a prospective multicenter study, including ten major trauma centers for collecting a high number of data in a short period of time (1991-1993). All pelvic injuries were documented consecutively using a special set of evaluation sheets. The study closed with 1,722 patients. A 2-year follow-up was completed for 486 patients injured in 1991 and 1992 after type B and C injuries, complex pelvic trauma, acetabulum fractures and a random 25% of A-type injuries (overall follow-up rate 73%). The follow-up included special "out-come" criteria. Of the pelvic ring injuries without significant peripelvic soft tissue involvement, 63.6% were A-type fractures, 21.0% B-type injuries and 15.5% C-type injuries. The rate of operative stabilization was 3.9% after A-type injuries, 37.3% after B-type injuries and 54.3% after C-type injuries. In isolated acetabular fractures ORIF was performed in 38.6%. The total lethality was 7.9% with a significant difference between "complex" pelvic trauma (21.3%) and patients without concomitant peripelvic injuries (7.2%). In 0.9% the pelvic injury was reported as the main cause of death. Pain at follow-up was observed in every classification group, the rate of completely "pain-free" patients being 55% after A-type, 41% after B-type and 27% after C-type fractures. Malfunction of micturia was reported by 7.6% of all patients, sexual malfunction by 11.6% of the males ("erectile dysfunction") and 2.2% of the female ("dysparneuria"). Scaled by the recently developed "outcome score", the radiological result showed anatomical healing after 90.8% of the B-type and 74.6% of the C-type injuries. On the other hand, the clinical result was rated as good or excellent in only 70% of the B-type and 54% of the C-type injuries. Although progress in indications and treatment techniques has shown improved radiological results after unstable pelvic ring injuries when compared to earlier studies, the clinical result still remains unsatisfactory. Further analyses and studies must be conducted to identify the prognostic factors for the late sequelae. Whether it is possible influence these factors by additional surgical intervention cannot be answered at present.

Beta-carbolines in chronic alcoholics following trauma.

In our society every second polytraumatized patient is a chronic alcoholic. A patient's alcohol-related history is often unavailable and laboratory markers are not sensitive or specific enough to detect alcohol-dependent patients who are at risk of developing alcohol withdrawal syndrome (AWS) during their post-traumatic intensive care unit (ICU) stay. Previously, it has been found that plasma levels of norharman are elevated in chronic alcoholics. We investigated whether beta-carbolines, i.e. harman and norharman levels, could identify chronic alcoholics following trauma and whether possible changes during ICU stay could serve as a predictor of deterioration of clinical status. Sixty polytraumatized patients were transferred to the ICU following admission to the emergency room and subsequent surgery. Chronic alcoholics were included only if they met the DSM-III-R and ICD-10 criteria for alcohol dependence or chronic alcohol abuse/harmful use and their daily ethanol intake was > or =60 g. Harman and norharman levels were assayed on admission and on days 2, 4, 7 and 14 in the ICU. Harman and norharman levels were determined by high pressure liquid chromatography. Elevated norharman levels were found in chronic alcoholics (n = 35) on admission to the hospital and remained significantly elevated during their ICU stay. The area under the curves (AUC) showed that norharman was comparable to carbohydrate-deficient transferrin (CDT) and superior to conventional laboratory markers in detecting chronic alcoholics. Seventeen chronic alcoholics developed AWS; 16 of these patients experienced hallucinations or delirium. Norharman levels were significantly increased on days 2 and 4 in the ICU in patients who developed AWS compared with those who did not. An increase in norharman levels preceded hallucinations or delirium with a median period of approximately 3 days. The findings that elevated norharman levels are found in chronic alcoholics, that the AUC was in the range of CDT on admission and that norharman levels remained elevated during the ICU stay, support the view that norharman is a specific marker for alcoholism in traumatized patients. Since norharman levels increased prior to the onset of hallucinations and delirium it seems reasonable to investigate further the potential role of norharman as a possible substance which triggers AWS.

Neurophysiological assessment of peripheral nerve and spinal cord function in asymptomatic HIV-1 infection: results from the UCMSM/Medical Research Council neurology cohort.

As part of the Medical Research Council prospective study of the neurological complications of HIV infection, neurophysiological tests of spinal cord and peripheral nerve function were recorded in a cohort of homosexual or bisexual men. The studies included motor and sensory nerve conduction studies, vibration perception thresholds, somatosensory evoked potentials and motor evoked potentials elicited by magnetic stimulation. The results were compared with markers of immune function. The findings from 114 volunteers were analysed in a cross-sectional study. Fifty-nine were HIV-seropositive but asymptomatic, 26 had progressed to the symptomatic stages of HIV disease and 29 were persistently HIV-seronegative. There was some evidence of a mild sensory axonopathy in the symptomatic HIV-seropositive group. No differences were detected between the asymptomatic HIV-seropositive group and the HIV-seronegative comparison group. There were no consistently significant correlations between the neurophysiological measurements and CD4 counts and beta 2-microglobulin levels. On repeated testing, there was no evidence of a trend towards deterioration over a mean period of approximately 3 years in 36 HIV-seropositive subjects who remained asymptomatic compared with 22 HIV-seronegatives. These findings have failed to demonstrate neurophysiological evidence of spinal cord or peripheral nerve dysfunction in the asymptomatic stages of HIV infection.