The facioscapulohumeral muscular dystrophy Rasch-built overall disability scale (FSHD-RODS)

BACKGROUND AND OBJECTIVES

Facioscapulohumeral muscular dystrophy (FHSD) is a debilitating inherited muscle disease for which various therapeutic strategies are being investigated. Thus far, little attention has been given in FSHD to the development of scientifically sound outcome measures fulfilling regulatory authority requirements. The aim of this study was to design a patient-reported Rasch-built interval scale on activity and participation for FSHD.

METHODS

A pre-phase FSHD-Rasch-built overall disability scale (pre-FSHD-RODS; consisting of 159 activity/participation items), based on the World Health Organization international classification of disease-related functional consequences was completed by 762 FSHD patients (Netherlands: n = 171; UK: n = 287; United States: n = 221; France: n = 52; Australia: n = 32). A proportion of the patient cohort completed it twice (n = 230; interval 2-4 weeks; reliability studies). The pre-FSHD-RODS was subjected to Rasch analyses to create a model fulfilling its requirements. Validity studies were performed through correlation with the motor function measure.

RESULTS

The pre-FSHD-RODS did not meet the Rasch model expectations. Based on determinants such as misfit statistics and misfit residuals, differential item functioning, and local dependency, we systematically removed items until a final 38-inquiry (originating from 32 items; six items split) FSHD-RODS was constructed achieving Rasch model expectations. Adequate test-retest reliability and (cross-cultural and external) validity scores were obtained.

CONCLUSIONS

The FSHD-RODS is a disease-specific interval measure suitable for detecting activity and participation restrictions in patients with FSHD with good item/person reliability and validity scores. The use of this scale is recommended in the near future, to determine the functional deterioration slope in FSHD per year as a preparation for the upcoming clinical intervention trials in FSHD.

Congenital Titinopathy: Comprehensive characterization and pathogenic insights

OBJECTIVE

Comprehensive clinical characterization of congenital titinopathy to facilitate diagnosis and management of this important emerging disorder.

METHODS

Using massively parallel sequencing we identified 30 patients from 27 families with 2 pathogenic nonsense, frameshift and/or splice site TTN mutations in trans. We then undertook a detailed analysis of the clinical, histopathological and imaging features of these patients.

RESULTS

All patients had prenatal or early onset hypotonia and/or congenital contractures. None had ophthalmoplegia. Scoliosis and respiratory insufficiency typically developed early and progressed rapidly, whereas limb weakness was often slowly progressive, and usually did not prevent independent walking. Cardiac involvement was present in 46% of patients. Relatives of 2 patients had dilated cardiomyopathy. Creatine kinase levels were normal to moderately elevated. Increased fiber size variation, internalized nuclei and cores were common histopathological abnormalities. Cap-like regions, whorled or ring fibers, and mitochondrial accumulations were also observed. Muscle magnetic resonance imaging showed gluteal, hamstring and calf muscle involvement. Western blot analysis showed a near-normal sized titin protein in all samples. The presence of 2 mutations predicted to impact both N2BA and N2B cardiac isoforms appeared to be associated with greatest risk of cardiac involvement. One-third of patients had 1 mutation predicted to impact exons present in fetal skeletal muscle, but not included within the mature skeletal muscle isoform transcript. This strongly suggests developmental isoforms are involved in the pathogenesis of this congenital/early onset disorder.

INTERPRETATION

This detailed clinical reference dataset will greatly facilitate diagnostic confirmation and management of patients, and has provided important insights into disease pathogenesis. Ann Neurol 2018;83:1105-1124.

High Degree of Genetic Heterogeneity for Hereditary Cerebellar Ataxias in Australia

Genetic testing strategies such as next-generation sequencing (NGS) panels and whole genome sequencing (WGS) can be applied to the hereditary cerebellar ataxias (HCAs), but their exact role in the diagnostic pathway is unclear. We aim to determine the yield from genetic testing strategies and the genetic and phenotypic spectrum of HCA in Australia by analysing real-world data. We performed a retrospective review on 87 HCA cases referred to the Neurogenetics Clinic at the Royal North Shore Hospital, Sydney, Australia. Probands underwent triplet repeat expansion testing; those that tested negative had NGS-targeted panels and WGS testing when available. In our sample, 58.6% were male (51/87), with an average age at onset of 37.1 years. Individuals with sequencing variants had a prolonged duration of illness compared to those with a triplet repeat expansion. The detection rate in probands for routine repeat expansion panels was 13.8% (11/80). NGS-targeted panels yielded a further 11 individuals (11/32, 34.4%), with WGS yielding 1 more diagnosis (1/3, 33.3%). NGS panels and WGS improved the overall diagnostic rate to 28.8% (23/80) in 14 known HCA loci. The genetic findings included novel variants in ANO10, CACNA1A, PRKCG and SPG7. Our findings highlight the genetic heterogeneity of HCAs and support the use of NGS approaches for individuals who were negative on repeat expansion testing. In comparison to repeat disorders, individuals with sequencing variants may have a prolonged duration of illness, consistent with slower progression of disease.

Contributions of age and alcohol consumption to cerebellar integrity, gait and cognition in non-demented very old individuals

Gait disturbance and cognitive changes are common with ageing. The cerebellum contributes to motor coordination and participates in various aspects of cognition. However, no research has investigated the possible cerebellar contribution to gait and cognition in non-demented very old individuals. The current study aimed to determine the associations between indices of cerebellar size (vermal area and total volume) and measures of motor and cognitive integrity, as well as the role of variables known to impact on cerebellar size (alcohol consumption and chronological age) in a sample of 111 community dwellers (mean age: 85 years; range: 81-97 years). A marginally significant association was present between age and total vermal area. Significant correlations between current daily alcohol intake and some vermal areas were observed. These associations were more pronounced in men, particularly after controlling for cerebrum size. Multiple linear regression models revealed limited unique contributions of cerebellar predictors to neurological and cognitive measures. In summary, the results indicate that the cerebellum may be susceptible to alcohol-related shrinkage in non-demented very old individuals, more so in men, even at low dose. It also appears that the observed changes in cerebellum size in this population contribute little to neurological and cognitive changes.

Cognitive, extrapyramidal, and magnetic resonance imaging predictors of functional impairment in nondemented older community dwellers: the Sydney Older Person Study

OBJECTIVES

To identify the clinical correlates of functional incapacity in the community living "old-old."

DESIGN

Cross-sectional.

SETTING

Community-based.

PARTICIPANTS

One hundred six nondemented people aged 80 to 94.

MEASUREMENTS

Participants were medically and cognitively assessed, underwent magnetic resonance imaging scanning (MRI), and were interviewed regarding their functional status: activities of daily living (ADLs), instrumental ADLs (IADLs), and the complex IADL functions of reading, hobbies, and socializing.

RESULTS

Dependency in IADLs, but not ADLs, was present. After controlling for age, sex, and education, extrapyramidal (EP) signs were significantly associated with two of the three IADLs, with EP signs comprising a composite score of 10 EP signs (e.g., resting tremor) and a 5-meter timed walk. Cognitive test performance on a range of tests was also associated with functional status. A hierarchical model confirmed the association between the EP signs and cognitive test performance and functional scores, but no "pattern" of cognitive association emerged. Hippocampal volume was associated with socializing.

CONCLUSION

This study has shown that many nondemented very old people living in the community are losing capacity to perform IADL functions and that areas of incapacity are associated with the presence of EP signs and impaired cognition. These results highlight the need for health workers to include an assessment of EP and cognitive status in their evaluation of older persons living in the community, even in the context of a lack of dementia diagnosis. Furthermore, it signifies the need to directly evaluate IADL function to identify need for intervention and support if required. This group of old-old individuals may now be considered the "survivors" of their cohort, and early detection of the difficulties they are experiencing will enable clinicians to respond appropriately, thus providing them a higher quality of life for their years to come.

Improving stroke outcomes in NSW: A study of GP perspectives

Stroke is the third leading cause of death in western society, imposing a heavy economic burden on communities worldwide. This study investigated NSW general practitioners? (GPs) views on stroke services. A postal survey was conducted of 296 randomly-selected GPs in NSW (60% response fraction). The main outcome measures were: satisfaction with access to specialists and services; GPs? views on the usefulness of quality indicators when referring patients for carotid endarterectomy; GPs? views about services to enhance stroke outcomes. GPs were satisfied with their access to private vascular laboratories (n=199, 67.2%), casualty/ emergency rooms for stroke patients (n=156, 52.7%), and medical beds for acute stroke in their local hospital (n=157, 53.0%). However, rural and remote GPs were significantly less likely than urban GPs to be satisfied with access to neurologists (?2=12.44, P<0.001), vascular surgeons (?2=8.57, P=0.003), public vascular laboratories (?2=9.46, P=0.002), private vascular laboratories (?2=5.19, P=0.02), and multidisciplinary stroke services (?2=6.09, P=0.014). GPs rated discharge planning most highly as a strategy to improve stroke outcomes (n=260, 87.8%). Our results invite particular attention to rural access to diagnostic, preventive and treatment stroke services. Discharge planning to ensure seamless transfer of care from hospital to general practice is also important.

Subcortical vascular disease and functional decline: a 6-year predictor study

OBJECTIVES

To identify predictors of activity of daily living (ADL) and instrumental activity of daily living (IADL) decline in a population with subcortical vascular dementia (SVD) and to evaluate potential mechanism of decline.

DESIGN

Longitudinal.

SETTING

Hospital-based.

PARTICIPANTS

Computed tomographic (CT) scanning identified 77 participants as having subcortical infarction.

MEASUREMENTS

Participants were neurologically, neuropsychologically, behaviorally, and functionally assessed four times over 5.82 years. Baseline data were grouped into four modules: basic demographic and risk factor, CT scan, neurological and other clinical, and neuropsychological and behavioral. Multivariate analysis determined predictors of decline in ADLs and IADLs.

RESULTS

Predictors of ADL decline were age, alcohol consumption, coordination, snout reflex, and performance on a neuropsychological test (Block Design). Predictors of IADL decline were predominantly cognitive and included the presence of paratonia and performance on the two neuropsychological tests (attention and memory tasks).

CONCLUSION

These findings suggest that cognitive impairments are most likely to have an effect on IADL function, because the skills involved are complex and involve integrative activity, whereas physical and cognitive impairments combined are likely to compromise ADL function, given the more basic and physical nature of the functions involved. These findings indicate that in people with SVD, both ADL and IADL status should be monitored, because, for many, decline in function over time is likely, and thus the provision of appropriate support required.

Nucleic acid vaccines: tasks and tactics

There are no adequate vaccines against some of the new or reemerged infectious scourges such as HIV and TB. They may require strong and enduring cell-mediated immunity to be elicited. This is quite a task, as the only known basis of protection by current commercial vaccines is antibody. As DNA or RNA vaccines may induce both cell-mediated and humoral immunity, great interest has been shown in them. However, doubt remains whether their efficacy will suffice for their clinical realization. We look at the various tactics to increase the potency of nucleic acid vaccines and divided them broadly under those affecting delivery and those affecting immune induction. For delivery, we have considered ways of improving uptake and the use of bacterial, replicon or viral vectors. For immune induction, we considered aspects of immunostimulatory CpG motifs, coinjection of cytokines or costimulators and alterations of the antigen, its cellular localization and its anatomical localization including the use of ligand-targeting to lymphoid tissue. We also thought that mucosal application of DNA deserved a separate section. In this review, we have taken the liberty to discuss these enhancement methods, whenever possible, in the context of the underlying mechanisms that might argue for or against these strategies.

McLeod neuroacanthocytosis: genotype and phenotype

McLeod syndrome is caused by mutations of XK, an X-chromosomal gene of unknown function. Originally defined as a peculiar Kell blood group variant, the disease affects multiple organs, including the nervous system, but is certainly underdiagnosed. We analyzed the mutations and clinical findings of 22 affected men, aged 27 to 72 years. Fifteen different XK mutations were found, nine of which were novel, including the one of the eponymous case McLeod. Their common result is predicted absence or truncation of the XK protein. All patients showed elevated levels of muscle creatine phosphokinase, but clinical myopathy was less common. A peripheral neuropathy with areflexia was found in all but 2 patients. The central nervous system was affected in 15 patients, as obvious from the occurrence of seizures, cognitive impairment, psychopathology, and choreatic movements. Neuroimaging emphasized the particular involvement of the basal ganglia, which was also detected in 1 asymptomatic young patient. Most features develop with age, mainly after the fourth decade. The resemblance of McLeod syndrome with Huntington's disease and with autosomal recessive chorea-acanthocytosis suggests that the corresponding proteins--XK, huntingtin, and chorein--might belong to a common pathway, the dysfunction of which causes degeneration of the basal ganglia.

Overcoming the poor immunogenicity of a protein by DNA immunization as a fusion construct

The production of antibodies against poorly immunogenic proteins is problematic. Often there is a failure to generate such antibodies. Furthermore, antibodies against other specificities are frequently induced. We describe a simple approach, analogous to conjugation to a protein carrier, whereby immunization with naked DNA was used to raise antibody to a highly homologous and poorly immunogenic allotypic protein. Deoxyribonucleic acid encoding the protein of interest was fused to DNA encoding the Fc region of a foreign Ig, resulting in increased immunogenicity. The potential applications of this approach include the production of antisera and mAb to allotypic variants, mutant proteins, and proteins that are highly conserved between species.

Delayed rejection of fetal pig pancreas in CD4 cell deficient mice was correlated with residual helper activity

CD4 cells have been shown to play a dominant role in the rejection of xenografts. Depletion of murine CD4 cells by injecting anti-CD4 antibody prolongs the graft survival, but does not prevent its rejection. For a more stable phenotype, we used genetically modified mice. To test whether the delayed rejection is caused by incomplete depletion of CD4 cells, we evaluated the response to fetal pig pancreas (FPP) xenografts in three types of CD4 cell deficient mice. They are MHC class II deficient mice (MHC II(o/o), CD4 deficient mice (CD4(o/o)) and a novel type of CD4 cell deficient mice (designated GK). GK mice were rendered permanently and completely CD4 deficient by transgenic expression of anti-CD4 antibody, whereas both MHC II(o/o) and CD4(o/o) mice have a residual helper cell population. FPP grafts in wild type mice were rejected within a week, whereas FPP grafts survived up to 4 weeks in MHC II(o/o) and CD4(o/o) mice. Survival of grafts in GK mice was even longer (8 weeks). Differences in histology were also noted. Rejecting grafts in MHC II(o/o) and wild-type mice were infiltrated with both eosinophils and mononuclear cells, whereas the infiltrates in CD4(o/o) and GK mice were exclusively mononuclear cells. Immunohistochemistry showed that they were primarily CD8 cells. The immune response to FPP was clearly different in the three types of CD4 cell deficient mice. Splenocytes of MHC II(o/o) 3 weeks post-transplant with FPP produced substantial amounts of IFN-gamma and IL-5, whereas splenocytes of CD4(o/o) mice produced low levels of IFN-gamma but no detectable IL-5. At similar times, these cytokines were not detected in GK mice. Furthermore, CD4(o/o) mice were capable of mounting helper dependent, although reduced, IgG responses to FPP antigens, while GK mice were not. The above results indicate that residual helper activity in some types of CD4 cell deficient mice could still contribute to xenograft rejection. Caution needs to be exercised where such mice are used as models of CD4 cell deficiency. Also, because there is eventual rejection of xenograft FPP in GK mice which lack detectable helper activity, we argue that these mice are a better model to investigate the involvement of CD4-independent rejection mechanisms.

CD4 help-independent induction of cytotoxic CD8 cells to allogeneic P815 tumor cells is absolutely dependent on costimulation

Mice made transgenic (Tg) for a rat anti-mouse CD4 Ab (GK mice) represent a novel CD4-deficient model. They not only lack canonical CD4 cells in the periphery, but also lack the residual aberrant Th cells that are found in CD4-/- mice and MHC class II-/- mice. To analyze the role of CD4 help and costimulation for CTL induction against alloantigens, we have assessed the surface and functional phenotype of CD8 cells in vivo (e.g., clearance of allogeneic P815 cells) and in vitro. In our CD4-deficient GK mice, CTL responses to allogeneic P815 cells were induced, albeit delayed, and were sufficient to eliminate P815 cells. Induction of CTL and elimination of allogeneic P815 cells were inhibited both in the presence and absence of CD4 cells by temporary CD40 ligand blockade. This indicated that direct interaction of CD40/CD40L between APCs and CD8 cells may be an accessory signal in CTL induction (as well as the indirect pathway via APC/CD4 interaction). Furthermore, whereas in CTLA4Ig single Tg mice P815 cells were rejected promptly, in the double Tg GK/CTLA4Ig mice CTL were not induced and allogeneic P815 cells were not rejected. These findings suggest that CD40/CD40L is involved in both CD4-dependent and CD4-independent pathways, and that B7/CD28 is pivotal in the CD4-independent pathway of CTL induction against allogeneic P815 cells.

Meningeal involvement in Wegener's granulomatosis

We describe a rare neurological manifestation of Wegener's granulomatosis, meningeal involvement, which occurred despite therapy resulting in disease quiescence in other organs. Clinical, radiographic, and neuropathological features are described.

A patient with mania and photoconvulsive epilepsy

OBJECTIVE

To describe a young patient who had a comorbidity of mania and photoconvulsive epilepsy.

CLINICAL PICTURE

This patient presented with a clinical picture of mania which proved difficult to treat until an EEG revealed the presence of photoconvulsive epilepsy.

TREATMENT

Treatment with haloperidol and lithium was unsuccessful but the addition of carbamazepine produced a dramatic response. Haloperidol was stopped and the patient maintained on lithium and carbamazepine.

OUTCOME

A successful outcome was achieved with carbamazepine and the patient has remained well on this treatment for 2 years.

CONCLUSIONS

The authors postulate that there may be an association between photoconvulsive epilepsy and mania, perhaps on a kindling basis. The literature pertaining to the psychiatric aspects of photoconvulsive epilepsy is reviewed.

Calcification of cervical ganglia: case report

We describe a 44-year-old woman with progressive cervical pain in whom plain films of the cervical spine showed only minor syndesmophyte formation when the patient first presented. However, after 5 weeks, repeat films demonstrated heavy symmetrical calcification of the cervical dorsal root ganglia. A review of the literature did not reveal a previous description of these findings.

Eosinophilic meningitis: cause of a chronic pain syndrome

Three tourists developed eosinophilic meningitis after visiting the Fijian Islands. Two had a severe and long lasting illness with chronic intractable pain. In one patient electrophysiological studies and MRI scan of the brain were abnormal and provided evidence of both radicular and cerebral parenchymal involvement by the most likely causative agent, Angiostrongylus cantonensis.

Perineural spread of cutaneous head and neck cancer. Its orbital and central neurologic complications

The ability of cutaneous squamous cell carcinoma of the face to cause ophthalmoplegia or central nervous system dysfunction via perineural spread is not well recognized. Five patients presenting to a general neurology unit are described in whom partial or complete ophthalmoplegia developed following fifth and seventh cranial nerve involvement by cutaneous squamous cell carcinoma. Two patients subsequently developed a contralateral hemiparesis; and one, multiple cranial nerve palsies as the tumor spread centrally. Normal radiologic findings or complete healing of the primary skin lesion caused delay in the diagnosis in three of the patients. When ophthalmoplegia or central nervous system dysfunction develops as a consequence of perineural spread of cutaneous facial cancer, management is palliative.

Cognitive and motor dysfunction in Parkinson's disease. Clinical, performance, and computed tomographic correlations

The neuropathologic and pathophysiological relationship of specific to more generalized cognitive dysfunction in Parkinson's disease (PD) remains incompletely understood. This issue was examined in a study of 39 patients with PD, utilizing standardized clinical measures, computerized neuropsychological tests, and quantitative computed tomography. Disorders of visuospatial discrimination and perceptual-motor function closely paralleled motor scores, suggesting a common neuropathologic basis. Caudate nuclear and mesocortical dopamine depletion play a role in this context. More generalized cognitive dysfunction occurred in older patients with a somewhat longer disease duration, more advanced parkinsonism, and computed tomographic evidence of subcortical and frontal cortical atrophy but without significant cerebral atrophy when compared with age-matched controls. Further prospective clinicopathologic studies will be required to clarify the relative contribution of the primary dopaminergic dysfunction, age-related changes, Alzheimer-type pathologic condition, and other coexisting neurotransmitter deficits to the dementia seen in PD.

Insulin resistance and regulation of serum amino acid levels in myotonic dystrophy

To quantify the degree of whole body insulin resistance in patients with myotonic dystrophy and to determine if these same patients display signs of a whole body decrease in the action of insulin on amino acid uptake and glucose disposal, three separate 120 min studies employing the euglycaemic insulin clamp technique (20, 80 and 200 m-units min-1 m-2) were performed on five ambulatory patients with myotonic dystrophy. The results were compared with findings obtained in identical studies in 21 normal volunteers. Myotonic dystrophy patients showed a slower, less marked decline in the serum concentration of insulin sensitive amino acids (threonine, valine, leucine, isoleucine, tyrosine, phenylalanine) during all three insulin infusions compared with normals. The greatest difference occurred at the low physiological elevations of insulin produced by the 20 m-units min-1 m-2 infusion. Alanine levels fell significantly below baseline in patients with myotonic dystrophy after 60 and 120 min of insulin infusion with all three rates of insulin infusion. Normal subjects had only a minimal, insignificant decline in arterialized alanine concentrations during the three different insulin infusions. Creatinine adjusted rates of whole body glucose disposal were 30-40% lower in the myotonic dystrophy group at all three doses of insulin compared with the normals. This demonstrates that their insulin resistance was not due simply to a reduction in muscle mass. The overall pattern of findings in these studies of patients with myotonic dystrophy indicates that there is a whole body derangement in the regulation of circulating amino acid levels by insulin as well as a marked decrease in the action of this hormone in stimulating glucose uptake by target tissues.

Acalculia following a dominant-hemisphere subcortical infarct

A 60-year-old, right-handed woman experienced persistent impairment of calculating ability following a subcortical infarct involving the head of the left caudate nucleus, the anterior superior putamen, and the anterior limb of the internal capsule extending superiorly into the periventricular white matter. Acalculia resulted from defects of numerical syntax, the loss of ability to manipulate mathematical concepts, and impaired working memory.

Reye syndrome associated with aspirin therapy for systemic lupus erythematosus

A 14-year-old girl in whom Reye syndrome developed during aspirin therapy for an inflammatory disorder proven to be systemic lupus erythematosus is reported. This case and similar cases of Reye syndrome in patients with juvenile rheumatoid arthritis suggest that an etiologic relationship exists between salicylate therapy and Reye syndrome in children with collagen vascular disorders.

Whole body insulin resistance in myotonic dystrophy

To quantitate the degree of whole body insulin resistance in patients with myotonic dystrophy, three separate euglycemic insulin infusions were given to ambulatory patients and the results compared with findings in normal control subjects. Basal glucose and insulin values were similar for the two groups. There was no significant difference in insulin clearance rates between normal subjects and patients at the three insulin infusion rates used. A highly significant decrease in the whole body glucose disposal rate was seen during the 120-minute insulin infusion in the patients with myotonic dystrophy compared with normal subjects at all three insulin dosages (20 mU/m2/min: 2.18 +/- 0.29 [standard error] versus 5.49 +/- 1.72 mg/kg/min, p less than 0.0001; 80 mU/m2/min: 4.16 +/- 0.34 versus 8.49 +/- 0.45 mg/kg/min, p less than 0.0001; 200 mU/m2/min: 5.22 +/- 0.53 versus 10.06 +/- 0.50 mg/kg/min, p less than 0.0001). These marked decreases in glucose disposal rates for the patients were adjusted in accordance with their 24-hour urinary creatinine excretion rate to correct for the difference in muscle mass between patients and controls. This adjusted glucose disposal rate was 15 to 25% lower (p less than 0.02) in the patients with myotonic dystrophy at insulin infusion rates of 20 and 80 mU. During the 200 mU insulin infusions, the adjusted glucose disposal rate remained lower than that in normal subjects but was of borderline statistical significance. These studies suggest that moderately severe whole body insulin resistance is responsible for the postprandial hyperinsulinemia typically seen in patients with myotonic dystrophy.

Adult-onset Still's disease with an associated severe restrictive pulmonary defect: a case report

A 21-year-old black female with an 18-month history of adult Still's disease developed symptoms and objective findings of restrictive lung disease. The pulmonary function abnormalities persisted unchanged for an additional 18 months despite moderate doses of prednisone. This complication has not been previously described in association with adult Still's disease.

Hemispheric infarction after herpes zoster ophthalmicus

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Skeletal muscle catabolism in amyotrophic lateral sclerosis and chronic spinal muscular atrophy

ALS and chronic spinal muscular atrophy are characterized by wasting of skeletal muscle, suggesting accelerated catabolism or reduced synthesis of muscle protein. We studied seven patients with ALS and three with chronic spinal muscular atrophy using 24-hour urinary 3-methylhistidine excretion as a measure of the rate of muscle catabolism and 24-hour urinary creatinine excretion as an index of significantly and similarly higher in both groups of patients than in controls (p less than 0.0005), implying a state of accelerated skeletal muscle protein catabolism in these diseases.

Experimental potassium depletion myopathy

Myopathic morphological changes were observed in the calf muscles of rats maintained on a potassium-depleted diet for 30-50 days. Light-microscopic changes were more severe in the superficial gastrocnemius muscle fibres and included pallor, swelling and vacuolation, progressing to necrosis, mononuclear cell infiltration and phagocytosis. Mitochondrial disruption, transverse tubular dilatation, membranous body formation and vacuolation were seen on ultrastructural examination. Both vacuoles and subsarcolemmal membranous bodies were shown to be in continuity with the transverse tubular system. More advanced myopathic changes were those of sarcomere destruction and muscle fibre necrosis. Morphological changes resemble those of human potassium depletion myopathy. Ineffective energy metabolism and focal ischaemia due to impaired vasodilatation are proposed as mechanisms for the myopathy of potassium depletion.

Identical twins with papilloedema and cranial nerve palsies

Central nervous system involvement has not been reported previously as a manifestation of sarcoidosis in monozygotic twins. Twin sisters developed multiple cranial nerve palsies and papilloedema within a two month period. Clinical features and the course of their diseases were remarkably similar.