An upgraded interferometer-polarimeter system for broadband fluctuation measurements

Measuring high-frequency fluctuations (above tearing mode frequencies) is important for diagnosing instabilities and transport phenomena. The Madison Symmetric Torus interferometer-polarimeter system has been upgraded to utilize improved planar-diode mixer technology. The new mixers reduce phase noise and allow more sensitive measurements of fluctuations at high frequency. Typical polarimeter rms phase noise values of 0.05°-0.07° are obtained with 400 kHz bandwidth. The low phase noise enables the resolution of fluctuations up to 250 kHz for polarimetry and 600 kHz for interferometry. The importance of probe beam alignment for polarimetry is also verified; previously reported tolerances of ≤0.1 mm displacement for equilibrium and tearing mode measurements minimize contamination due to spatial misalignment to within acceptable levels for chords near the magnetic axis.

Novel HSPB1 mutation causes both motor neuronopathy and distal myopathy

Objective:

To identify the cause of isolated distal weakness in a family with both neuropathic and myopathic features on EMG and muscle histology.

Methods:

Case study with exome sequencing in 2 affected individuals, bioinformatic prioritization of genetic variants, and segregation analysis of the likely causal mutation. Functional studies included Western blot analysis of the candidate protein before and after heat shock treatment of primary skin fibroblasts.

Results:

A novel HSPB1 variant (c.387C>G, p.Asp129Glu) segregated with the phenotype and was predicted to alter the conserved α-crystallin domain common to small heat shock proteins. At baseline, there was no difference in HSPB1 protein levels nor its binding partner αB-crystallin. Heat shock treatment increased HSPB1 protein levels in both patient-derived and control fibroblasts, but the associated increase in αB-crystallin expression was greater in patient-derived than control fibroblasts.

Conclusions:

The HSPB1 variant (c.387C>G, p.Asp129Glu) is the likely cause of distal neuromyopathy in this pedigree with pathogenic effects mediated through binding to its partner heat shock protein αB-crystallin. Mutations in HSBP1 classically cause a motor axonopathy, but this family shows that the distal weakness can be both myopathic and neuropathic. The traditional clinical classification of distal weakness into “myopathic” or “neuropathic” forms may be misleading in some instances, and future treatments need to address the pathology in both tissues.

Frequency of rare recessive mutations in unexplained late onset cerebellar ataxia

Sporadic late onset cerebellar ataxia is a well-described clinical presentation with a broad differential diagnosis that adult neurologists should be familiar with. However, despite extensive clinical investigations, an acquired cause is identified in only a minority of cases. Thereafter, an underlying genetic basis is often considered, even in those without a family history. Here we apply whole exome sequencing to a cohort of 12 patients with late onset cerebellar ataxia. We show that 33 % of ‘idiopathic’ cases harbor compound heterozygous mutations in known ataxia genes, including genes not included on multi-gene panels, or primarily associated with an ataxic presentation.

A novel de novo STXBP1 mutation is associated with mitochondrial complex I deficiency and late-onset juvenile-onset parkinsonism

Mutations in STXBP1 have recently been identified as a cause of infantile epileptic encephalopathy. The underlying mechanism of the disorder remains unclear and, recently, several case reports have described broad and progressive neurological phenotypes in addition to early-onset epilepsy. Herein, we describe a patient with early-onset epilepsy who subsequently developed a progressive neurological phenotype including parkinsonism in her early teens. A de novo mutation in STXBP1 (c.416C>T, p.(Pro139Leu)) was detected with exome sequencing together with profound impairment of complex I of the mitochondrial respiratory chain on muscle biopsy. These findings implicate a secondary impairment of mitochondrial function in the progressive nature of the disease phenotype.

Electron kinetic effects on interferometry, polarimetry and Thomson scattering measurements in burning plasmas (invited)

At anticipated high electron temperatures in ITER, the effects of electron thermal motion on Thomson scattering (TS), toroidal interferometer/polarimeter (TIP), and poloidal polarimeter (PoPola) diagnostics will be significant and must be accurately treated. The precision of the previous lowest order linear in τ = Te/mec(2) model may be insufficient; we present a more precise model with τ(2)-order corrections to satisfy the high accuracy required for ITER TIP and PoPola diagnostics. The linear model is extended from Maxwellian to a more general class of anisotropic electron distributions that allows us to take into account distortions caused by equilibrium current, ECRH, and RF current drive effects. The classical problem of the degree of polarization of incoherent Thomson scattered radiation is solved analytically exactly without any approximations for the full range of incident polarizations, scattering angles, and electron thermal motion from non-relativistic to ultra-relativistic. The results are discussed in the context of the possible use of the polarization properties of Thomson scattered light as a method of Te measurement relevant to ITER operational scenarios.

Nutrition and public health: division of labour in the study of nutrition

This article draws inferences from changes in the style of a nutrition journal which was originally published by the Commonwealth Department of Health, and is now published by the Australian Dietitians' Association. The changes reflect developments in the field of nutrition, towards more 'scientific' styles of inquiry and publishing, against the backdrop of a division of labour in which (mainly male) laboratory scientists produced scientific knowledge which was then communicated by (mainly female) dietitians and nutritionists. Consistent with the approach of the 'new public health', this paper argues that reliance upon 'scientific' methods alone diverts attention from the social, economic and political conditions which help explain not only the improvements earlier in the century, but current difficulties in bringing about further improvements.

Structural dynamics of the human androgen receptor: implications for prostate cancer and neurodegenerative disease

The AR (androgen receptor) is a ligand-activated transcription factor that mediates the action of the steroids testosterone and dihydrotestosterone. Alterations in the AR gene result in a number of clinical disorders, including: androgen-insensitivity, which leads to disruption of male development; prostate cancer; and a neuromuscular degenerative condition termed spinal bulbar muscular atrophy or Kennedy's disease. The AR gene is X-linked and the protein is coded for by eight exons, giving rise to a C-terminal LBD (ligand-binding domain; exons 4-8), linked by a hinge region (exon 4) to a Zn-finger DBD (DNA-binding domain; exons 2 and 3) and a large structurally distinct NTD (N-terminal domain; exon 1). Identification and characterization of mutations found in prostate cancer and Kennedy's disease patients have revealed the importance of structural dynamics in the mechanisms of action of receptors. Recent results from our laboratory studying genetic changes in the LBD and the structurally flexible NTD will be discussed.

[Surgical indications in spinal trauma]

Surgical indications in spinal trauma remain a controversial topic. In general, unstable cervical injuries such as displaced odontoid fractures, burst fractures or tear drop fractures require surgical intervention. Thoracolumbar compression injuries without posterior wall involvement or significant kyphosis can be treated conservatively. Surgery is indicated in fractures-dislocations and burst fractures with significant canal narrowing and/or major kyphosis. The role of emergency decompression as well as that of steroids remain uncertain since no study to date has convincingly proven their efficacy.

Coping effectiveness training reduces depression and anxiety following traumatic spinal cord injuries

OBJECTIVE

To extend the findings of a pilot study that evaluated a brief group-based psychological intervention aimed at improving psychological adjustment, self-perception and enhancing adaptive coping following spinal cord injury. The theoretical underpinnings of the Coping Effectiveness Training (CET) Programme are Lazarus and Folkman's (1984) cognitive theory of stress and coping, and cognitive behavioural therapy techniques.

DESIGN

A controlled trial comparing patients that received the CET intervention with matched controls on measures of psychological adjustment and coping.

METHOD

A total of 45 intervention group participants and 40 matched controls were selected from inpatients at a hospital-based spinal cord injury centre. Outcome measures of anxiety and depression, self-perception and coping were collected before, immediately after and 6 weeks following the intervention.

RESULTS

Intervention group participants showed a significant reduction in depression and anxiety, compared to the matched controls following the intervention. There was no evidence of a significant change in the pattern of coping strategies used by the intervention group compared to controls. The intervention group alone completed measures of self-perception. There was a significant decrease in the discrepancy between participants' 'ideal' self and 'as I am', and between 'as I would be without the injury' and 'as I am' following the intervention and at follow-up. Significant correlations were also found between self-perception, and anxiety and depression over time.

CONCLUSIONS

These results confirm the findings of the pilot study, that the CET intervention facilitated a significant improvement in psychological adjustment to spinal cord injury. It is proposed that this improvement may be understood in terms of changing participants' negative appraisals of the implications of spinal cord injury with the result of increasing the perceived manageability of its consequences. Such decatastrophizing alters appraisals which are associated with current mood. Participants found shared discussion and problem-solving to be particularly helpful. Avenues for further research are discussed.

Phenocopies in a large GCH1 mutation positive family with dopa responsive dystonia: confusing the picture?

BACKGROUND

Dopa responsive dystonia (DRD) is a disorder characterised by childhood onset dystonia but a wide range of clinical presentations has now been described.

OBJECTIVE

To study a large Canadian family with presumed DRD.

METHODS

The clinical features of the family were collected before molecular genetic mutational analysis.

RESULTS

All nine individuals in whom a clinical diagnosis of DRD was definite or probable were heterozygous for a GCH1 gene deletion. However, eight of nine possibly clinically affected members did not carry the GCH1 mutation.

CONCLUSIONS

Great care must be taken in diagnosing DRD even in families with the classic phenotype, because of potential phenocopies of the disease.

Surface enhanced resonance Raman scattering imaging of Langmuir-Blodgett monolayers of bis (benzimidazo) thioperylene

The synthesis, spectroscopic characterization and surface-enhanced spectroscopy of a new electro active organic material bis (benzimidazo) thioperylene (Monothio BZP) are reported. Langmuir monolayers of Monothio BZP were successfully formed on water subphase and characterized by the pi-A surface-pressure area isotherm. Langmuir-Blodgett (LB) monomolecular layers of Monothio BZP were fabricated onto glass substrates and onto silver island films for surface-enhanced spectroscopic studies. The results of surface-enhanced resonance Raman scattering (SERRS), SERRS imaging and surface-enhanced fluorescence (SEF) studies for Monothio BZP LB monolayers are reported. Raman imaging (global imaging and point-by-point mapping) of the SERRS signal for a single monomolecular layer on silver islands were obtained using the 514.5 nm laser line. The SERRS imaging permits a visualization of the variation of the SERRS intensity across of the rough metal surface. The SEF was recorded for the excimer emission of aggregates in the LB film. The distance dependence and the enhancement factor of SEF were determined using fatty acid spacing layers. A temperature dependence study of the LB monolayer SERRS and SEF spectra was carried out between -190 degrees and + 200 degrees C confirming the thermal stability of the LB monolayer on silver. The specificity and the sensitivity of SERRS signal on metal island films was probed using mixed LB films with 0.01% molecular ratio of Monothio BZP in Arachidic Acid (AA). The micro-Raman SERRS spectra from ca. 10(-3) attomole of the dye were recorded.

Asymptomatic intracranial hypertension in disorders of CSF circulation in childhood--treated and untreated

Twelve patients are described who were found to have asymptomatic intracranial hypertension monitored over an extended (6 months to 6 years) period. There were three groups: 5 patients with treated hydrocephalus with an apparently functioning shunt, 4 patients with untreated hydrocephalus, clinically and radiologically nonprogressive, and 3 patients with pseudotumor cerebri, 2 treated and 1 untreated. Although the magnitude of the intracranial pressure changes varied, all patients had abnormal baseline pressures together with repeated A and B waves. In no case was there any clinical manifestation of raised intracranial pressure and in all cases ventricular size remained constant over the period of evaluation. The clinical and pathophysiological implications of these findings are discussed.

Post traumatic stress disorder and spinal cord injuries

Post Traumatic Stress Disorder (PTSD) was first recognised by psychiatric international classification systems in 1980 and a wealth of research and treatment literature has developed since. This paper provides a review of PTSD and Spinal Cord Injuries. A brief history of the disorder is provided before descriptions of the defining characteristics, assessment and differential diagnoses. The paper provides an overview of the incidence and prevalence of PTSD and risk factors within the general population, before considering both veteran and non-veteran research within spinal cord injuries. Pharmacological and psychological approaches to the treatment of PTSD are also discussed. The review closes with recommendations for future research into the prevalence and treatment of PTSD in spinal cord injuries.

Long-term follow-up of unilateral pallidotomy in advanced Parkinson's disease

BACKGROUND

Although the short-term benefits of posteroventral pallidotomy for patients with advanced Parkinson's disease have been well documented, little is known about the long-term outcome of the procedure.

METHODS

We conducted a long-term follow-up study of a cohort of 40 patients who had undergone unilateral posteroventral medial pallidotomy between 1993 and 1996. Twenty patients were not evaluated because they had undergone a second surgical procedure (11 patients) or had died (2) or because they had dementia or another debilitating illness (4), lived too far away (1), or had been lost to follow-up (2). We conducted serial postoperative assessments of parkinsonism in the remaining 20 patients while they were taking medications ("on" period) and after overnight withdrawal of the drugs ("off" period). The mean follow-up time was 52 months (range, 41 to 64).

RESULTS

The combined off-period score for activities of daily living and motor function on the Unified Parkinson's Disease Rating Scale was 18.0 percent better at the last evaluation than at base line (95 percent confidence interval, 4.9 to 31.0 percent; P=0.01). Significant improvements were also evident in the off-period scores for contralateral tremor (65.4 percent improvement, P=0.007), rigidity (43.2 percent, P=0.03), and bradykinesia (18.2 percent, P=0.04) and in the on-period score for contralateral dyskinesia (70.6 percent, P<0.001). Changes in medication did not contribute to the sustained improvement. The 20 patients who could not be included in the long-term analysis had similar base-line characteristics but a worse response to surgery at six months.

CONCLUSIONS

In the group of patients with advanced Parkinson's disease who could be enrolled in our long-term follow-up study of unilateral posteroventral medial pallidotomy (20 patients from the original cohort of 40), significant early improvements in off-period contralateral signs of parkinsonism were sustained for up to five and a half years. There was a sustained significant improvement in on-period contralateral dyskinesia but not in other on-period signs of parkinsonism.

Obesity in leukemia survivors: the familial contribution

A high prevalence of obesity in survivors of acute lymphoblastic leukemia (ALL) has been described, but genetic and social influence in obesity has not been analyzed in this group of patients. The authors studied a population of 33 long-term (25 females, 8 males) in first remission who had reached their final height. All patients received cranial irradiation as part of their central nervous system (CNS)-directed therapy and no patient received growth hormone. The body mass index (BMI: weight/height2) of patients and their biological parents was calculated and submitted to statistical analysis. Obesity was defined as BMI greater than the 85th centile. No excessive obesity was found among the males at final height. Fifty-six percent of the females were obese. In this group of 14 obese female survivors 59% had obese mother, but only 14% had obese fathers. The results indicate a significant maternal predisposition to obesity.

Long-term outcomes for surgically resected craniopharyngiomas

OBJECTIVE

This retrospective study critically analyzed the long-term functional outcomes and tumor recurrence rates for surgically treated craniopharyngiomas.

METHODS

This study used an outcome classification system that included functioning vision, independent versus dependent living, Karnofsky Performance Scale scores, academic levels, work status, and psychological status. Tumor recurrence rates were analyzed with respect to the extent of surgical resection and adjunctive radiotherapy.

RESULTS

For 121 patients, with a mean follow-up period of 10 years, the overall "good outcome" rate was 60.3%. Factors associated with poor outcomes included lethargy at presentation, visual deterioration, papilledema, tumor calcification, hydrocephalus, and tumor adhesiveness at surgery. Gross total resection was associated with good outcomes (P = 0.017) and decreased risk of recurrence (P = 0.024). Subtotal resection was associated with increased risk of tumor recurrence (P = 0.0235). The highest risk of recurrence was in the subtotal resection/no radiation group (P = 0.0001). There were no differences in outcomes or recurrence rates between pediatric and adult patients. There were also no differences in outcomes or recurrence rates between papillary and adamantinous tumors. Approximately one-third of patients exhibited morbid obesity, and permanent diabetes insipidus was observed for 25 patients.

CONCLUSION

A rigorous evaluation of outcomes for tumors such as craniopharyngiomas must consider not only the extent of resection, as judged by postoperative imaging, but also the long-term physical, intellectual, and psychological functioning of the patients.

Posteroventral medial pallidotomy in Parkinson's disease

There has been a resurgence in the use of functional neurosurgery for Parkinson's disease. An important factor that has played a role in this development is the recent understanding of the functional anatomy of the basal ganglia including a knowledge of the changes in the activities of neurons in the internal segment of the globus pallidus (Gpi) and the subthalamic nucleus (STN) in Parkinson's disease as well as the knowledge of the presence of segregated functional loops within the basal ganglia which include a sensory-motor loop that involves the posteromedial globus pallidus rather than the anterior GPi where earlier pallidotomy lesions had been made. Laitinen reintroduced the modern posteroventral medial pallidotomy (PVMP) in 1992. Since then it has become clear that this treatment has major effects on levodopa-induced dyskinesias and, unlike Vim thalamotomy, improves bradykinesia and rigidity as well as tremor. In this report, we review a number of topics related to PVMP including the clinical results of pallidotomy available in the literature as well as an update of our own 2 year follow-up data, studies evaluating factors that might predict the subsequent response to pallidotomy, the neuropsychological effects of the procedure, results of imaging studies including the correlation of clinical effects with lesion location, the question of bilateral pallidotomy and pallidotomy combined with deep brain stimulation and finally whether PVMP is effective in other parkinsonian disorders.

Relationship of lesion location to clinical outcome following microelectrode-guided pallidotomy for Parkinson's disease

The purpose of this study was to examine the relationship between lesion location and clinical outcome following globus pallidus internus (GPi) pallidotomy for advanced Parkinson's disease. Thirty-three patients were prospectively studied with extensive neurological examinations before and at 6 and 12 months following microelectrode-guided pallidotomy. Lesion location was characterized using volumetric MRI. The position of lesions within the posteroventral region of the GPi was measured, from anteromedial to posterolateral along an axis parallel to the internal capsule. To relate lesion position to clinical outcome, hierarchical multiple regression analysis was used. The variance in outcome measures that was related to preoperative scores and lesion volume was first calculated, and then the remaining variance attributable to lesion location was determined. Lesion location along the anteromedial-to-posterolateral axis within the GPi influenced the variance in total score on the Unified Parkinson's Disease Rating Scale in the postoperative 'off' period, and in 'on' period dyskinesia scores. Within the posteroventral GPi, anteromedial lesions were associated with greater improvement in 'off' period contralateral rigidity and 'on' period dyskinesia, whereas more centrally located lesions correlated with better postoperative scores of contralateral akinesia and postural instability/gait disturbance. Improvement in contralateral tremor was weakly related to lesion location, being greater with posterolateral lesions. We conclude that improvement in specific motor signs in Parkinson's disease following pallidotomy is related to lesion position within the posteroventral GPi. These findings are consistent with the known segregated but parallel organization of specific motor circuits in the basal ganglia, and may explain the variability in clinical outcome after pallidotomy and therefore have important therapeutic implications.

Pallidal stimulation in Parkinson's disease patients with a prior unilateral pallidotomy

OBJECTIVE

To evaluate, in a double-blind fashion, the efficacy of deep brain stimulation of the internal segment of the globus pallidus (GPi) contralateral to a previous unilateral medial pallidotomy (MP).

METHODS

This pilot study involved 4 patients with a previous MP and one previously unoperated patient unable to tolerate any antiparkinsonian drugs. One of the patients with a prior unilateral MP had two electrodes implanted in the contralateral side, one in GPi and one in Vim thalamus. Detailed neurologic assessments were performed after overnight drug withdrawal and in the drug "on" state at baseline, 1 week and 3 months (in all), and 9 and 12 months (one) with patients and evaluators blinded to the status of stimulation.

RESULTS

GPi stimulation resulted in improvements in "off-period" contralateral bradykinesia, rigidity and tremor in all patients. Dyskinesias and freezing episodes were ameliorated in one patient each but dyskinesias were transiently induced in another. The patient with GPi + Vim electrodes had complete resolution of contralateral tremor with thalamic stimulation but less benefit from acute GPi stimulation. One patient experienced a single seizure one week post-op and no other surgical complications were observed.

CONCLUSIONS

Deep brain stimulation can be applied safely and effectively in patients who have already had a pallidotomy on the contralateral side. The effect of stimulation at different sites on different symptom profiles and levodopa-induced dyskinesias requires further evaluation.

Female exposure to high G: chronic adaptations of cardiovascular functions

INTRODUCTION

Exposure to microgravity is associated with increased leg venous compliance and reductions in cardiac output, baroreflex functions, and tolerance to orthostatism. However, the effects of chronic exposure to high-G environments are unknown. In addition, there is evidence that females have lower orthostatic tolerance than males, although the underlying mechanisms are unclear. Therefore, we tested the hypotheses that high-G training will enhance baroreflex and orthostatic functions and that females will demonstrate similar adaptations compared with males.

METHODS

Calf venous compliance, baroreflex function, and orthostatic performance were measured in six men and seven women before and after repeated exposures on the centrifuge (G-training) for 4 wk, 3 times/wk, with gradual levels of G starting with +3 Gz without G-suit protection during week 1 and advancing to +9 Gz with G-suit protection by the end of week 4. Calf venous compliance was measured by occlusion plethysmography using impedance rheographic recordings of volume change. Baroreflex function was assessed from beat-by-beat changes in heart rate (HR) and mean arterial pressure (MAP) that were measured before, during, and after a Valsalva maneuver strain at 30 mmHg expiratory pressure. The orthostatic performance of reflex responses was assessed from beat-by-beat changes in HR, MAP, stroke volume (SV), cardiac output (Q; by impedance plethysmography), and systemic peripheral resistance during the last 10 cardiac beats of a 4-min squat position and during the initial 10 cardiac beats in a standing position.

RESULTS

G-training increased calf compliance in both men and women. SV and Q were increased during the squat-to-stand test in the males, but not in the females, following G-training and provided protection against the development of acute hypotension in the men.

CONCLUSIONS

G-training caused adaptations in orthostatic functions opposite to those observed following exposure to microgravity environments. However, adaptations to G-training were limited in females, a finding that may provide a physiological basis for their lower simulated combat tracking performance during simulated aerial combat maneuvers compared with males.

Use of Lipid Drugs With Acute Myocardial Infarction Patients: An Examination of Physician Prescribing Behaviors

BACKGROUND: Clinical trials have shown that the use of lipid-lowering agents in postmyocardial infarction (MI) patients reduces rates of subsequent coronary events, reduces coronary artery bypass surgery rates, and improves survival. Physician decisions to prescribe lipid-lowering drugs is influenced by a number of patient factors, including age, medical history, and serum cholesterol levels. The purpose of this study was to examine physician behaviors in prescribing lipid-lowering therapy in patients after acute MI. METHODS AND RESULTS: A retrospective study was conducted at a local community-based hospital. A total of 129 patients with validated acute MI, hospitalized between January 1996 and December 1996, was included in the study sample. Variables abstracted included patient age, sex, race, primary diagnosis, medical history, lipid-lowering interventions of the discharge plan, and other discharge instructions regarding smoking cessation, activity, and dietary modification. Descriptive analysis was performed. The study showed that only 7 subjects (8.8%) were discharged on lipid-lowering drugs. Several patients who did not undergo therapy had either a low-density lipoprotein concentration of <130 (n = 13), a high-density lipoprotein concentration of >50 (n = 6), or were on hormone replacement therapy (n = 3). Dietary modification was advised in 100% of subjects (n = 54) for whom the data were included in the charts. CONCLUSIONS: The results of this descriptive study suggests that lipid-lowering drugs are being utilized at low rates in the secondary prevention of acute MI. However, additional risk-lowering factors may play a role in the decision to discharge without drugs. Because of potential side effects associated with their use, a prudent path appears to be the norm in prescription of lipid-lowering drug therapy for MI patients.

Living with a person who has Parkinson's disease: the spouse's perspective by stage of disease. Parkinson's Study Group

The objective of this study was to examine the experience of spouses caregiving for their spouse with Parkinson's disease (PD) and to determine whether their experiences differed by stage of disease. By using a cross-sectional design and mail questionnaire data from 380 spouse caregivers across 23 sites of the Parkinson Study Group, key caregiver variables were examined by stage of PD. Three categories of variables--caregiver role strain (10 measures), caregiver situation (four measures), and caregiver characteristics (four measures)--were analyzed by using t tests with Bonferroni correction. Specific types and amounts of role strain accumulated as the disease progressed, and they differed significantly between stages (p < 0.05). In the caregiving situation, the mean number of caregiving tasks tripled by stage 4/5. Negative changes in lifestyle plus decreases in predictability in caregivers' lives increased significantly in late-stage disease (p < 0.05). Caregiver characteristics of physical health and preparedness did not significantly differ across stages of disease. Depression was significantly higher by stage 4/5. Mutuality, the positive quality of the relationship as perceived by the caregiving spouse, declined beginning at stage 2. Caregiver strain is experienced across all stages of PD and accumulates significantly as the disease progresses. This study defines types and amounts of strain by stage of disease, which will be helpful in designing formal intervention trials to provide more effective help for spouse caregivers.

Posteroventral medial pallidotomy in advanced Parkinson's disease

BACKGROUND

Posteroventral medial pallidotomy sometimes produces striking improvement in patients with advanced Parkinson's disease, but the studies to date have involved small numbers of patients and short-term follow-up.

METHODS

Forty patients with Parkinson's disease underwent serial, detailed assessments both after drug withdrawal ("off" period) and while taking their optimal medical regimens ("on" period). All patients were examined preoperatively and 39 were examined at six months; 27 of the patients were also examined at one year, and 11 at two years.

RESULTS

The percent improvements at six months were as follows: off-period score for overall motor function, 28 percent (95 percent confidence interval, 19 to 38 percent), with most of the improvement in the contralateral limbs; off-period score for activities of daily living, 29 percent (95 percent confidence interval, 19 to 39 percent); on-period score for contralateral dyskinesias, 82 percent (95 percent confidence interval, 72 to 91 percent); and on-period score for ipsilateral dyskinesias, 44 percent (95 percent confidence interval, 29 to 59 percent). The improvements in dyskinesias and the total scores for off-period parkinsonism, contralateral bradykinesia, and rigidity were sustained in the 11 patients examined at two years. The improvement in ipsilateral dyskinesias was lost after one year, and the improvements in postural stability and gait lasted only three to six months. Approximately half the patients who had been dependent on assistance in activities of daily living in the off period before surgery became independent after surgery. The complications of surgery were generally well tolerated, and there were no significant changes in the use of medication.

CONCLUSIONS

In late-stage Parkinson's disease, pallidotomy significantly reduces levodopa-induced dyskinesias and off-period disability. Much of the benefit is sustained at two years, although some improvements, such as those on the ipsilateral side and in axial symptoms, wane within the first year. The on-period symptoms that are resistant to dopaminergic therapy do not respond to pallidotomy.

Surgical interventions in the treatment of Parkinson's disease (PD) and essential tremor (ET): medial pallidotomy in PD and chronic deep brain stimulation (DBS) in PD and ET

Surgical treatments for PD and ET are promising. Medial Pallidotomy, the surgical lesioning of the pallidum, often improves symptoms of long-standing PD. We enrolled twenty-seven late stage PD patients for unilateral medial pallidotomy who were then assessed by the Core Assessment Program for Intracranial Transplantation (CAPIT) protocol. One year after surgery persistent improvement was seen contralateral to the lesion in the following features: drug-induced dyskinesias (92%), akinesia (38%), rigidity (51%), and tremor (42%). Complications included transient dysarthria (7 patients), facial weakness (9 patients), limb weakness (1 patient), swallowing problems (4 patients) and intracerebral haemorrhage (1 patient). Thalamic DBS may improve tremor in PD and ET patients. Therefore, we enrolled fifteen patients (9 PD and 6 ET patients) with disabling tremor, unresponsive to medication. They were assessed by the United Parkinson's Disease Rating Scale (UPDRS) and the Tremor Rating Scale (for PD and ET patients, respectively). Three months after surgery, limb tremor contralateral to stimulation improved by 71% in PD patients and 76% in ET patients. Complications included transient paresthesias (all), confusional state (1 patient) and intracerebral bleed (1 patient). Unilateral medial pallidotomy safely improves some Parkinsonian symptoms contralateral to the lesion. Thalamic DBS may effectively and safely improve contralateral limb tremor in PD and ET.

Pattern of liver, kidney, heart, and intestine allograft rejection in different mouse strain combinations

With advances in microsurgery and molecular biology, the mouse model for organ transplantation has become increasingly popular. However, knowledge about these models is limited, as only a small number of centers have experience with murine models. In this study, we compared the rejection pattern after liver, kidney, heart, and small bowel transplantation in the three different mouse strain combinations: (1) C57BL/6 (H2b)-->BALB/c (H2d), (2) BALB/c (H2d)-->CBA (H2k), and (3) C57BL/6-->C3H/HeN (H2k). Our study demonstrated that mouse allograft survival varies depending on the organ graft and on the donor-recipient strain combinations. The majority of liver allografts were spontaneously accepted despite complete MHC disparity. A mixed pattern of acute rejection and acceptance occurred in kidney recipients depending on the donor-recipient strain combination. All the heart grafts developed rejection and all the intestinal grafts were rapidly rejected with no spontaneous acceptance. The criteria for rejection, the potential applications, and the limitations of each model are discussed. The models described in this article provide a number of useful choices for organ transplantation research.