Wasted leg syndrome: An atypical slowly-progressive form of lower motor neuron disease

We describe four male patients with wasted-leg syndrome, with predominant asymmetric thigh atrophy and weakness that stabilized after a period of slow progression (follow-up 7-18 years). Two patients had an Indian ethnic background and two were Portuguese, without known Indian ancestry. Other mimicking disorders were excluded, but one Indian patient was later diagnosed with CADASIL. Electromyography (EMG) revealed severe chronic neurogenic changes in proximal leg muscles, and mild changes in distal leg muscles, but EMG of the upper limbs was normal. Upper motor neuron signs were absent clinically and on transcranial magnetic stimulation. This seems to represent a variant of the common wasted-leg syndrome presentation.

Muscular cramp: causes and management

Muscular cramp is a common symptom in healthy people, especially among the elderly and in young people after vigorous or peak exercise. It is prominent in a number of benign neurological syndromes. It is a particular feature of chronic neurogenic disorders, especially amyotrophic lateral sclerosis. A literature review was undertaken to understand the diverse clinical associations of cramp and its neurophysiological basis, taking into account recent developments in membrane physiology and modulation of motor neuronal excitability. Many aspects of cramping remain incompletely understood and require further study. Current treatment options are correspondingly limited.

Seizure Induction by Alcohol in Patients with Epilepsy Experience in two Hospital Clinics

We surveyed 70 epileptic patients attending a general neurology clinic and 64 patients attending an epilepsy clinic to determine the incidence of alcohol-related seizures. Seven (10%) of the neurology clinic patients and 9 (15%) of the epilepsy clinic patients reported exacerbation of their seizures with alcohol. In the first group, two had been heavy drinkers when under-age, two had features of alcohol dependence, and three had experienced resolution of seizures following cessation of their drinking. In the second group, five drank 4 units/day or more, and one drank more heavily. The importance of alcohol in the causation of these patients' seizures had not previously been appreciated. The relationship of alcoholism to epilepsy has been recognized for many years, but the role of alcohol in the exacerbation of primary epilepsy, and in triggering seizures in epileptic patients is often not recognized. Control of alcohol ingestion is an important factor in the management of epilepsy.

Iatrogenic Neuromuscular Disorders: A Review

The frequency of iatrogenic neuromuscular disorders has only recently been appreciated. Pressure palsies, especially common peroneal nerve palsies following bed rest or surgical procedures, are well recognized and easily preventable disorders. Mononeuropathies may also result from direct injuries to nerves, especially from venepuncture or attempted arterial cannulation in the axilla (O'Keefe 1980) or antecubital fossa, when the median nerve is particularly at risk. Stretch injuries to the lower cervical roots or to the lower cords of the brachial plexus may complicate sternal thoracotomy (Winer & Harrison 1982). However, most iatrogenic disorders of nerve and muscle are due to the unwanted effects of drugs used in therapeutic dosage. They are thus difficult to prevent. However, early detection is possible and this may prevent the development of severe disabilities.

Plasma level of club-cell (CC-16) predicts outcome in amyotrophic lateral sclerosis

OBJECTIVES

The club cell protein (CC-16) is a biomarker associated with respiratory distress and pulmonary inflammation. We evaluated CC-16 as a candidate biomarker for respiratory failure in amyotrophic lateral sclerosis (ALS).

MATERIALS AND METHODS

We studied 81 ALS patients and 30 matched controls. We used an ALS-related measure of functional capacity, and tested forced vital capacity (FVC) and the amplitude of the diaphragmatic response by phrenic nerve stimulation (PhrenAmpl). Plasma CC-16 levels were measured in venous blood. Kaplan-Meier survival curves were plotted to evaluate risk to non-invasive ventilation and death in patients with abnormal CC-16 levels.

RESULTS

CC-16 levels were significantly raised in ALS patients (10.56 ng/mL ± 6.84 vs 8.34 ng/mL ± 3.10, P = .02), and in 17% of them, CC-16 level was above the upper cutoff value (mean + 2.5SD). CC-16 levels did not correlate with age, onset region, disease duration, functional status, FVC, and PhrenAmpl. In patients with increased CC-16 level, the risk of non-invasive was greater in the following 6 months (P = .01) and tended to have higher mortality in the following 30 months (P = .07).

CONCLUSIONS

We propose that increased CC-16 levels is a marker of lung inflammatory response that associated with ventilatory insufficiency are related to impending respiratory failure, not fully predicted by conventional respiratory tests. The latter are limited by the moment of testing.

Defecation 2: Internal anorectal resistance is a critical factor in defecatory disorders

BACKGROUND

The aim of this study was to test our hypothesis that the reason why imaging is of little assistance in diagnosing "constipation" causes may be related to the high sensitivity of internal anorectal flow resistance in defecation to small changes in geometry. We applied a mathematical model to describe the effects on flow mechanics of observed changes in the shape of the rectum and anus during defecation.

METHODS

Three groups of patients were studied with video proctograms. Group 1 comprised 4 patients with normal defecation studied with video proctography or magnetic resonance imaging (MRI). Group 2 comprised 8 patients with fecal incontinence, studied by video X-ray electromyography. Group 3 comprised 8 patients with constipation evaluated by video MRI.

RESULTS

Three muscle vectors open the anorectal angle prior to defecation, causing the anorectal luminal diameter to increase to approximately twice its resting size. These vectors are forwards (anterior wall), backwards and downwards (posterior wall). Resistance to passage of a fecal bolus through the anorectum is determined by viscous friction against the anorectal wall and by the energy required to deform the bolus as it flows. The observed changes in anorectal geometry serve to reduce both the viscous friction in the anus and the deformation of the bolus, which reduces the force required to facilitate its passage through the anus. For example, if the effective diameter of the anus is doubled during defecation, the frictional resistance is reduced by a factor of 8.

CONCLUSIONS

The sensitivity of flow resistance to geometry explains why MRI or computed tomography (CT) scans taken during defecation are not often helpful in diagnosing causation. Small changes in geometry can have a disproportionate affect on flow resistance. Combining accurate directional measurements during dynamic MRI or CT scans taken during defecation with observations of bolus deformation, and if possible, simultaneous anorectal manometry, may provide clinically helpful insights on patients with anorectal evacuation disorders.

The neurogenic hypothesis of stress incontinence

There are a number of causes of incontinence. The common forms of urinary incontinence, faecal incontinence or double incontinence, are stress related, in that voiding of urine or faeces occurs in response to a sudden increase in pressure in the bladder or anorectum that is not opposed by an adequate pressure increase in the sphincteric region. This weakness of the sphincter mechanism is due to chronic partial denervation of the striated sphincter muscles of the pelvic floor, comprising the external and sphincter muscle and puborectalis (puboanalis) components of the voluntary anal sphincter musculature, and the periurethral and intramural components of the urinary striated sphincter musculature. Denervation of these muscles occurs progressively following injury initiated during childbirth and then sustained by repeated stretch-induced injury during straining behaviour at stool. Age-related changes to this innervation may also be important. Weakness of the pelvic floor, and perineal descent during straining, lead to secondary changes in the anatomy of the bladder neck, of the anorectal angle, and of the smooth muscle of the internal urinary and anal sphincters. The cystometric and anal manometric changes found in patients with stress incontinence are secondary to this neurogenic weakness of the pelvic floor.

Phase II/III randomized trial of TCH346 in patients with ALS

BACKGROUND

TCH346 exerts antiapoptotic effects by binding to glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and blocking the apoptotic pathway in which GAPDH is involved. Apoptosis is considered to be a key pathogenic mechanism in neurodegenerative diseases including ALS.

METHODS

Patients were randomly assigned in a double-blind fashion to receive either placebo or one of four doses of TCH346 (1.0, 2.5, 7.5, or 15 mg/day) administered orally once daily for at least 24 weeks. The primary outcome measure was the rate of change in the revised ALS functional rating scale (ALSFRS-R). The trial design included a 16-week lead-in phase to determine each patient's rate of disease progression. The between treatment comparison was adjusted for the individual pretreatment rates of progression. The study was powered to detect a 25% reduction in the rate of decline of the ALSFRS-R as compared with placebo. Secondary outcome measures included survival, pulmonary function, and manual muscle testing (MMT).

RESULTS

Five hundred ninety-one patients were enrolled at 42 sites in Europe and North America. There were no differences in baseline variables. There were no significant differences between placebo and active treatment groups in the mean rate of decline of the ALSFRS-R or in the secondary outcome measures (survival, pulmonary function, and MMT).

CONCLUSION

The trial revealed no evidence of a beneficial effect of TCH346 on disease progression in patients with ALS.

Comparison of the 40-item Amyotrophic Lateral Sclerosis Assessment Questionnaire (ALSAQ-40) with a short-form five-item version (ALSAQ-5) in a longitudinal survey

OBJECTIVES

To compare results on the 40-item Amyotrophic Lateral Sclerosis Assessment Questionnaire (ALSAQ-40) with those gained on the short-form five-item Amyotrophic Lateral Sclerosis Assessment Questionnaire (ALSAQ-5) in a longitudinal study.

DESIGN

Postal survey. Copies of the ALSAQ-40 which incorporates the five items of the ALSAQ-5, were completed on two occasions. Respondents were also asked to indicate how much change they had experienced since baseline on each of the five domains of the questionnaire.

SETTING

The database of all patient members of the Motor Neurone Disease Association for England, Wales and Northern Ireland.

SUBJECTS

Nine hundred and twenty-seven patient members returned questionnaires at baseline, and 764 completed questionnaires at both baseline and follow-up.

RESULTS

Results on the five dimensions of the ALSAQ-40 and ALSAQ-5 were found to be highly correlated, and 95% confidence intervals on mean scores were found to overlap for each dimension. The instruments both provide a similar picture of change in terms of their responsiveness. For example, effect sizes were calculated for patients who claimed their health had deteriorated a little since baseline, and gave almost identical results (e.g. for the Physical functioning domain effect sizes of 0.12 and 0.11 were found on the long and short measures respectively).

CONCLUSIONS

Results suggests that the ALSAQ-5 provides similar results to the ALSAQ-40 yet with considerable economy. In instances where a very brief health status measure is required then the ALSAQ-5 may be the instrument of choice.

The onset of amyotrophic lateral sclerosis

Two patients in whom both the neurological examination and electromyography (EMG) were normal prior to the onset of amyotrophic lateral sclerosis (ALS) are reported. In each patient, the onset of ALS some 18 months later was clearly defined clinically and confirmed by subsequent EMG studies. These unique observations show that ALS commences at a defined time, and that there is early generalisation with an initial phase of rapid progression.

Minicore myopathy with ophthalmoplegia caused by mutations in the ryanodine receptor type 1 gene

BACKGROUND

Minicore myopathy (multi-minicore disease [MmD]) is a congenital myopathy characterized by multifocal areas with loss of oxidative activity on muscle biopsy. MmD is clinically heterogeneous and distinct phenotypes have been associated with recessive mutations in either the selenoprotein N (SEPN1) or the skeletal muscle ryanodine receptor (RYR1) gene, also implicated in central core disease and malignant hyperthermia. External ophthalmoplegia is an additional finding in a subset of patients with MmD.

OBJECTIVE

To clinically and genetically examine families with MmD and external ophthalmoplegia.

METHODS

The authors investigated 11 affected individuals from 5 unrelated families. Clinical, histopathologic, and imaging studies were performed and RYR1 haplotyping and mutational analysis were carried out.

RESULTS

All patients had multiple cores involving the entire fiber diameter on longitudinal sections. Weakness and wasting in the shoulder girdle, scoliosis, moderate respiratory impairment, and feeding difficulties were prominent. In contrast to SEPN1-related myopathies, soleus was more severely affected than gastrocnemius on muscle MRI. Haplotyping suggested linkage to the RYR1 locus in informative families and mutational screening revealed four novel RYR1 mutations in three unrelated families; in addition, functional haploinsufficiency was found in one allele of two recessive cases.

CONCLUSION

These findings expand the phenotypic spectrum associated with mutations in the skeletal muscle ryanodine receptor (RYR1) gene. Recessive mutations of domains commonly affected in malignant hyperthermia appear to be particularly prevalent in multi-minicore disease with external ophthalmoplegia and might suggest a different pathomechanism from that involved in central core disease.

Contribution of the pudendal nerve to sensation of the distal rectum

Background

Anal and rectal sensory mechanisms and pudendal nerve function are important in the control of faecal continence. The contribution of the pudendal nerve to sensation of the distal rectum was investigated.

Methods

Heat thresholds in the anal canal, distal and mid rectum were measured using a specially designed thermoprobe. Rectal sensory threshold volumes were measured using the balloon distension method. Needle electrodes were inserted into the external anal sphincter. Pudendal nerve block was performed through a perineal approach, and completeness assessed by loss of electromyographic activity. Heat and rectal volume thresholds were measured again following unilateral and bilateral pudendal nerve block.

Results

The technique was successful in four of six volunteers. Bilateral pudendal nerve block produced complete anaesthesia to heat in the anal canal (P = 0·029), but had no effect on heat thresholds in the distal or mid rectum. Rectal sensory threshold volumes were also unaffected by pudendal nerve anaesthesia.

Conclusion

Anal canal sensation is subserved by the pudendal nerve, but this nerve is not essential to nociceptive sensory mechanisms in the distal or mid rectum. The transition between visceral control mechanisms in the lower rectum and somatic mechanisms in the anal canal may have functional importance in the initiation of defaecation and the maintenance of continence.

The anal reflex elicited by cough and sniff: validation of a neglected clinical sign

BACKGROUND

It is unclear whether contraction of the external anal sphincter (EAS) following a voluntary cough is an integral component of the cough response itself, or a reflex response to the abdominal and pelvic floor dynamics induced by the cough. Clinical experience suggests a reflex origin for this response.

OBJECTIVE

To compare motor latencies for intercostal, abdominal, and EAS muscle contraction after transcranial magnetic stimulation with those following voluntary coughing and sniffing.

METHODS

A needle electrode inserted into the EAS measured responses, which were confirmed by tonic electromyographic recording. Direct motor latencies from the cerebral cortex to the intercostal, rectus abdominis and EAS muscles were obtained using transcranial magnetic stimulation. Sniff and cough induced responses were also recorded in these muscles.

RESULTS

The results suggest that EAS responses following a voluntary cough or sniff represent a polysynaptic reflex.

CONCLUSIONS

As the cough induced anal reflex response is consistent and easily elicited, its use in clinical neurological examination is appropriate.

Clinical neurophysiology of ALS

The neurophysiology of amyotrophic lateral sclerosis is important not only in relation to diagnosis, but also in the development of methods to follow progress, and the effects of putative therapies, in the disease. Quantitative techniques can be applied to the measurement of reinnervation using needle electromyogram. The methodology of motor unit number estimation may be useful in measuring loss of functioning motor units in groups of patients but variability in the measurement using current methods limits its sensitivity in the evaluation of individual patients. Conventional neurophysiological measurements, expressed as a multimetric index, may be useful in assessing progress. The cortical and upper motor neuron system can be assessed using transcortical magnetic stimulation protocols, and cortical excitability may be measured by the peristimulus histogram method. In this review the advantages, limitations and promise of these various methods is discussed, in order to indicate the direction for further neurophysiological studies in this disorder.

Measuring mental health in amyotrophic lateral sclerosis (ALS): a comparison of the SF-36 Mental Health Index with the Psychological General Well-Being Index

OBJECT

The purpose of this study was to compare the performance of the five-item mental health dimension of SF-36 (the Mental Health Index, MHI-5) with that of the 22-item Psychological General Well-Being Index (PGWB) in patients presenting with amyotrophic lateral sclerosis/motor neuron disease, using tests of reliability and validity.

DESIGN

A questionnaire-based survey of patients diagnosed with ALS across 15 European countries.

SAMPLE

Patients presenting at neurological clinics for treatment of their ALS were asked to join the survey.

RESULTS

1048 patients with ALS have been recruited, of whom 861 (82.2%) have returned baseline questionnaires. There was evidence supporting the internal consistency of both instruments, and for their construct validity in distinguishing between groups, in terms of gender and age. The scores on the two instruments were highly correlated (Spearman rank correlation 0.85).

CONCLUSION

Both the MHI-5 and the PGWB showed high levels of construct validity and internal reliability in this patient group. The MHI-5 has comparable psychometric performance to the PGWB, and can be used to measure and compare mental health in defined populations.

Amyotrophic lateral sclerosis: current understanding

Amyotrophic lateral sclerosis (ALS), or motor neuron disease (MND) as it is usually termed in the United Kingdom, is a fatal degenerative disease resulting in progressive weakness and wasting of voluntary muscles. The disease is caused by degeneration of upper motor neurons in the motor cortex and of lower motor neurons in the brainstem and spinal cord. This combined loss of function causes spastic paralysis, flaccid muscle weakness, wasting, and fasciculations. The disease process spares the sensory, autonomic, and oculomotor neurons. ALS is the most common of the MND syndromes in adults. Although the cause of ALS is unknown, there is evidence that the excitatory neurotransmitter glutamate plays an important role in neuronal cell death in the disease. Several risk factors, such as exposure to welding and soldering, inhalation of lead vapor, exposure to chemicals, and electrical trauma are postulated as contributing to the pathogenesis of ALS. About 90% of all ALS patients have the sporadic form. Approximately 20% of all familial ALS cases are associated with mutations of the copper/zinc superoxide dismutase-1 gene. What is not clear is what factors contribute to the causation of the more common sporadic cases. The drug riluzole has neuroprotective effects in ALS and is the only disease-specific treatment available to date. Riluzole has been approved by the National Institute for Clinical Excellence for use in the National Health Service of the United Kingdom. Other treatments are aimed at managing the devastating symptoms of ALS.

Reproducibility of neurophysiological and myometric measurement in the ulnar nerve-abductor digiti minimi system

Reliability in strength and neurophysiological measurements is important in evaluating progression of neuromuscular diseases. No data are available on the variability of neurophysiological parameters as compared with maximal voluntary isometric contraction (MVIC) in the same muscles, in healthy subjects. A control population of 26 healthy subjects was studied twice on different days. We evaluated the reliability of neurophysiological parameters obtained from bilateral ulnar nerve stimulation, recording the response over the abductor digiti minimi (ADM) muscle, including distal motor latency, compound muscle potential amplitude and area, F-wave frequency and mean F-wave latency, and the derived neurophysiological index that we have described previously. MVIC force was measured in each session in both ADM muscles. The variances between the grouped data obtained in the two recording sessions were identical, indicating a low intrinsic variability with this experimental methodology. Comparison of the mean values obtained in the two sessions revealed no statistically significant differences. The reliability of these neurophysiological and strength measurements in the same nerve/muscle system suggests they may be useful in comparing the dynamics of weakness and neurophysiological change in neuromuscular disease.

ALS 2000: the past points to the future

In this introductory review a number of issues concerning the direction of future research in ALS are addressed in relation to current understanding of this disorder and its treatment. The importance of understanding the pathways leading to motor neuron dysfunction and death is emphasized. Contemporary epidemiology, understandably focussed on genetic markers for familial ALS, needs to be widened to include as yet undocumented susceptibility-related genetic traits. Potential avenues for therapy are considered, and the fundamental contemporary issue of clinical measurement is discussed. Neglected aspects of contemporary research, including disturbed axoplasmic flow, are brought to attention. The role of experiment derived from clinical observation, and vice versa, is described by reference to a number of past and recent contributions to the understanding of ALS.

Diagnostic delay in amyotrophic lateral sclerosis: what scope for improvement?

The average time taken from symptom onset to diagnosis in motor neuron disease is many months and has shown no sign of improving despite the introduction of riluzole therapy. We performed a retrospective analysis of the time to diagnosis in 57 patients using a structured interview with the patients and/or their carers. In this cohort, studied in England and Wales, the mean time from onset to diagnosis was 16.2 months. An initial incorrect diagnosis, refusal to consider the diagnosis when it was suggested by the informed patient, failure to consider a neurological cause for the patient's symptoms, and failure to make early referral to a neurologist were the major factors leading to delayed diagnosis. Bulbar symptoms were more likely to lead to correct diagnosis than limb-onset features. Ten of our patients made the diagnosis by consulting reference books or the Internet before they were informed of it by their physician.

Variant Alzheimer's disease with spastic paraparesis and cotton wool plaques is caused by PS-1 mutations that lead to exceptionally high amyloid-beta concentrations

We describe 3 new families affected by Alzheimer's disease with spastic paraparesis. In affected individuals, including the earliest known patient with this clinical syndrome, neuropathological examination revealed large "cotton wool" plaques similar to those we have previously described in a Finnish family. In the families in which DNA was available, presenilin-1 mutations were observed. Transfection of cells with these mutant genes caused exceptionally large increases in secreted Abeta42 levels. Furthermore, brain tissue from individuals with this syndrome had very high amyloid-beta concentrations. These findings define the molecular pathogenesis of an important subgroup of Alzheimer's disease and have implications for the pathogenesis of the disease in general.

The ALS Health Profile Study: quality of life of amyotrophic lateral sclerosis patients and carers in Europe

The measurement of functioning and well-being from the perspective of the patient has in recent years become central to the assessment of health and the evaluation of treatment regimes. The past decade has seen an enormous growth in the application of measures designed to assess quality of life in a vast array of medical specialties. However, the use of such measures in neurology has been relatively limited, and this has certainly been the case in amyotrophic lateral sclerosis (ALS). The European ALS Health Profile Study is a longitudinal survey of patients diagnosed with ALS or other motor neurone diseases in which patients are asked to complete questionnaires concerning their subjective health status. Data from clinical assessments are also collected. It is intended that the information collected will provide more systematic and detailed evidence of the impact of the disease from the perspective of the patient. This contribution documents results from baseline assessment obtained from data supplied by clinicians, carers and patients themselves. Three outcome measures are assessed in this paper: the SF-36, a generic measure of well being and functioning, the ALS Functional Rating Scale and the Carer Strain Index. The evidence presented here suggests that these measures provide a meaningful and valid picture of the impact of the disease. The data indicate that ALS has substantial adverse effects both upon the functioning and well being of patients and carers, as well as an association between the emotional health status of patients and carers, and between the physical health status of patients and carers.

Motor neuron disease: classification and nomenclature

The classification and nomenclature of motor neuron disease, whether sporadic or familial, is confused. For example, both the sporadic and familial motor neuron diseases are phenotypically heterogeneous and, in familial ALS, phenotypic heterogeneity correlates only weakly with different underlying mutations in the SOD1 gene. We propose a classification which is based on underlying causative mechanisms, where these are known, but which also recognizes different clinical phenotypes when the cause is unknown. This classification is flexible, and allows reattribution of clinical syndromes when their causation is understood. Currently uncertain associations--for example, a possible association of ALS with cancer--are given tentative recognition in this classification. In addition, this new classification recognizes geographical clustering and descriptions of unusual motor neuron disorder phenotypes of unknown origin in different parts of the world.

Shortening the time to diagnosis in ALS: the role of electrodiagnostic studies

The early diagnosis of ALS has become an issue in management of the disease with the introduction of a therapy. As more effective treatment becomes available early diagnosis will become increasingly important. Electromyography (EMG) has potential value in this area, but will need to be applied not only with conventional methods but also quantitatively in order to refine the accuracy of diagnosis itself, and to evaluate progression. If a treatment is effective then progression will not occur and one of the major cornerstones of current diagnosis will disappear. For early diagnosis much will depend on appropriate recognition of the possibility of amyotrophic lateral sclerosis by primary care physicians, and other specialists. A semi-quantitative evaluation, utilizing clinical and EMG assessments, would help in this appraisal.