Neuropathies related to hepatitis E virus infection: A prospective, matched case-control study

BACKGROUND

Acute hepatitis E virus (HEV) infection has recently emerged as a potential trigger for acute dysimmune neuropathies, but prospective controlled studies are lacking.

AIMS

To compare the frequency of concomitant acute HEV infection in patients with neuralgic amyotrophy (NA), Guillain-Barré syndrome (GBS), and Bell's palsy with a matched control population.

METHODS

Swiss multicenter, prospective, observational, matched case-control study over 3 years (September 2019-October 2022). Neurological cases with NA, GBS, or Bell's palsy were recruited within 1 month of disease onset. Healthy controls were matched for age, sex, geographical location, and timing of blood collection. Diagnostic criteria for acute hepatitis E were reactive serum anti-HEV IgM and IgG assays (ELISA test) and/or HEV RNA detection in serum by real-time polymerase chain reaction (RT-PCR). RT-PCR was performed on sera to confirm IgM positivity.

RESULTS

We included 180 patients (59 GBS, 51 NA, 70 Bell's palsy cases) and corresponding matched controls (blood donors) with median age 51 years for both groups and equal gender distribution. Six IgM+ cases were detected in the NA, two in the GBS, and none in the Bell's palsy group. Two controls were anti-HEV IgM-positive. At disease onset, most cases with acute HEV infection had increased liver enzymes. A moderate association (p = 0.027, Fisher's exact test; Cramér's V = -0.25) was observed only between acute HEV infection and NA.

CONCLUSION

This prospective observational study suggests an association between concomitant acute HEV infection and NA, but not with GBS or Bell's palsy.

Neuromuscular ultrasound standardized scanning techniques and protocols: Expert panel recommendations

Neuromuscular ultrasound has become an integral part of the diagnostic workup of neuromuscular disorders at many centers. Despite its growing utility, uniform standard scanning techniques do not currently exist. Scanning approaches for similar diseases vary in the literature creating heterogeneity in the studies as reported in several meta-analysis. Moreover, neuromuscular ultrasound experts including the group in this study have different views with regards to technical aspects, scanning protocols, and the parameters that should be assessed. Establishing standardized neuromuscular scanning protocols is essential for the development of the subspeciality to ensure uniform clinical and research practices. Therefore, we aimed to recommend consensus-based standardized scanning techniques and protocols for common neuromuscular disorders using the Delphi approach. A panel of 17 experts participated in the study, which consisted of three consecutive electronic surveys. The first survey included voting on six scanning protocols addressing the general scanning technique and five common categories of suspected neuromuscular disorders. The subsequent surveys focused on refining the protocols and voting on new steps, rephrased statements, or areas of non-agreement. A high degree of consensus was achieved on the general neuromuscular ultrasound scanning technique and the scanning protocols for focal mononeuropathies, brachial plexopathies, polyneuropathies, amyotophic lateral sclerosis, and muscle diseases. In this study, a group of neuromuscular ultrasound experts developed six consensus-based neuromuscular ultrasound scanning protocols that may serve as references for clinicians and researchers. The standardized protocols could also aid in achieving high-quality uniform neuromuscular ultrasound practices.

Lower motoneuron dysfunction impacts spontaneous motor recovery in acute cervical spinal cord injury

Paresis after spinal cord injury is caused by damage to upper and lower motoneurons and may differentially impact neurological recovery. This prospective monocentric longitudinal observational study investigated the extent and severity of lower motoneuron dysfunction and its impact on upper extremity motor recovery after acute cervical spinal cord injury. Pathological spontaneous activity at rest and/or increased discharge rates of motor unit action potentials recorded by needle electromyography (EMG) were taken as parameters for lower motoneuron dysfunction and its relation to the extent of myelopathy in the first available spine MRI was determined. Motor recovery was assessed by standardized neurological examination within the first 4 weeks (acute stage) and up to 1 year (chronic stage) after injury. Eighty-five muscles of 17 individuals with cervical spinal cord injury (neurological level of injury from C1 to C7) and a median age of 54 (28-59) were examined. The results showed that muscles with signs of lower motoneuron dysfunction peaked at the lesion center (Χ²[2,n=85]=6.6, p=0.04) and that the severity of lower motoneuron dysfunction correlated with T2-weighted hyperintense MRI signal changes in routine spine MRI at the lesion site (spearman ρ=0.31, p=0.01). Muscles exhibiting signs of lower motoneuron dysfunction, as indicated by pathological spontaneous activity at rest and/or increased discharge rates of motor unit action potentials, were associated with more severe paresis in both the acute and chronic stages after spinal cord injury (spearman ρ acute=-0.22, p=0.04 and chronic=-0.31, p=0.004). Moreover, the severity of lower motoneuron dysfunction in the acute stage was also associated with a greater degree of paresis (spearman ρ acute=-0.24, p=0.03 and chronic=-0.35, p=0.001). While both muscles with and without signs of lower motoneuron dysfunction were capable of regaining strength over time, those without lower motoneuron dysfunctions had a higher potential to reach full strength. Muscles with signs of lower motoneuron dysfunction in the acute stage displayed increased amplitudes of motor unit action potentials with chronic-stage needle EMG, indicating reinnervation through peripheral collateral sprouting as compensatory mechanism (Χ²[1,n=72]=4.3, p=0.04). Thus, lower motoneuron dysfunction represents a relevant factor contributing to motor impairment and recovery in acute cervical spinal cord injury. Defined recovery mechanisms (peripheral reinnervation) may at least partially underlie spontaneous recovery in respective muscles. Therefore, assessment of lower motoneuron dysfunction could help refine prediction of motor recovery following spinal cord injury.

Novel Autoantibodies in Idiopathic Small Fiber Neuropathy

Objective

Small fiber neuropathy (SFN) is clinically and etiologically heterogeneous. Although autoimmunity has been postulated to be pathophysiologically important in SFN, few autoantibodies have been described. We aimed to identify autoantibodies associated with idiopathic SFN (iSFN) by a novel high‐throughput protein microarray platform that captures autoantibodies expressed in the native conformational state.

Methods

Sera from 58 SFN patients and 20 age‐ and gender‐matched healthy controls (HCs) were screened against >1,600 immune‐related antigens. Fluorescent unit readout and postassay imaging were performed, followed by composite data normalization and protein fold change (pFC) analysis. Analysis of an independent validation cohort of 33 SFN patients against the same 20 HCs was conducted to identify reproducible proteins in both cohorts.

Results

Nine autoantibodies were screened with statistical significance and pFC criteria in both cohorts, with at least 50% change in serum levels. Three proteins showed consistently high fold changes in main and validation cohorts: MX1 (FC = 2.99 and 3.07, respectively, p = 0.003, q = 0.076), DBNL (FC = 2.11 and 2.16, respectively, p = 0.009, q < 0.003), and KRT8 (FC = 1.65 and 1.70, respectively, p = 0.043, q < 0.003). Further subgroup analysis into iSFN and SFN by secondary causes (secondary SFN) in the main cohort showed that MX1 is higher in iSFN compared to secondary SFN (FC = 1.61 vs 0.106, p = 0.009).

Interpretation

Novel autoantibodies MX1, DBNL, and KRT8 are found in iSFN. MX1 may allow diagnostic subtyping of iSFN patients. ANN NEUROL 2022;91:66–77

Limb Hypothermia for the Prevention of Chemotherapy-Induced Peripheral Neuropathy - Modality for Optimal Cooling

Chemotherapy-induced peripheral neuropathy (CIPN) is a common dose-limiting adverse effect of neurotoxic chemotherapeutic agents. Recent studies have suggested clinical utility of limb hypothermia in reducing CIPN. However, conventional cooling methods such as ice packs are unable to provide thermoregulated cooling and cause frostbites. Cooling modalities offering thermoregulation have been developed for sports injury and orthopaedic indications, but not explored for preventing CIPN. This study aims to determine the safety, tolerability and optimal parameters of three cooling modalities for delivery of limb hypothermia in healthy subjects, prior to testing in cancer patients for prevention of CIPN. Healthy subjects underwent limb hypothermia by either: continuous-flow cooling, cryocompression or frozen gloves. Skin temperatures and tolerance scores were monitored. Overall, 58 subjects underwent limb hypothermia. No adverse events were observed barring transient erythema. Both continuous-flow cooling and cryocompression are feasible, safe and tolerable methods for delivery of limb hypothermia. Cryocompression achieved lower skin temperatures than continuous-flow cooling with similar safety profiles. Frozen gloves were minimally tolerated. Cryocompression may provide greater efficacy in preventing CIPN, with clinical trials currently underway.

Concomitant limb cryocompression and scalp cooling to reduce paclitaxel-induced neuropathy and alopecia

e24157

Background: Scalp cooling is an FDA approved method to mitigate chemotherapy-induced alopecia (CIA) caused by paclitaxel. Chemotherapy-induced peripheral neuropathy (CIPN) is a dose limiting toxicity of paclitaxel. Several recent randomized studies have suggested limb hypothermia as a mechanism to ameliorate paclitaxel-induced neuropathy. The safety, tolerability and feasibility of concomitant limb hypothermia and scalp cooling to prevent these two common adverse effects of paclitaxel has not been previously studied. Methods: A proof-of-concept study was conducted in breast cancer patients receiving weekly paclitaxel chemotherapy. Each subject underwent concomitant scalp and four-limb cryocompression with each chemotherapy infusion (3 hours) for a maximum of 12 cycles. Limb cryocompression was administered at cyclic pressure (5-15 mmHg) and temperatures starting at 11°C (established as lowest tolerable temperature in a separate healthy volunteer study) and adjusted according to patient tolerability. Skin surface temperature and tolerance scores were recorded. CIPN was assessed via EORTC Quality of Life Questionnaire-CIPN before (QOLpre), after completion (QOLpost) and 3-months post chemotherapy (QOL3m). Results: Fifteen patients enrolled in the study, of which 14 completed all 12 cycles of concomitant scalp cooling and limb cryocompression during chemotherapy without any side effects barring transient erythema over the limbs. None had intolerance to scalp cooling. Eight patients safely tolerated 12 cycles of cryocompression at 11°C. Of the remaining, 6 completed all 12 cycles at device temperatures ranging from 14-25°C. One patient withdrew at the 6th cycle, finding 25°C intolerable. Median QOLpre was 19 (range 17-19), QOLpost 20 (18-29) (p = 0.04, Wilcoxon signed-rank) and QOL3m was 19 (18-21) (vs QOLpre; p = 1). QOL showed no significant differences from pre-chemotherapy to 3 months post-chemotherapy suggesting preservation of nerve function. Conclusions: Delivery of concomitant scalp cooling and limb cryocompression is feasible, safe and generally well-tolerated. Future limb hypothermia trials should not preclude patients from undergoing scalp-cooling concomitantly to reduce CIA. Clinical trial information: NCT03248193 .

Evaluation of radial nerve continuity early after humeral shaft fracture fixation using high-resolution nerve ultrasonography: a pilot study of feasibility

BACKGROUND

This study evaluated the feasibility and reliability of high-resolution ultrasonography (HRUS) of the radial nerve in the early, postoperative period after operative stabilization of humeral shaft fractures.

METHODS

This study enrolled patients between September 2015 and April 2018 with a humeral shaft fracture who were assessed with HRUS within 2 weeks after surgery. Based on the ultrasound artifacts, the examiners subjectively defined quality of ultrasound as "bad" or "good." The cross-sectional area of the radial and the posterior interosseous nerve was recorded at predefined locations. The radial nerve was scanned axially in the whole course to identify nerve continuity.

RESULTS

Of 44 patients who underwent operations for humeral shaft fracture, HRUS was used to assess 15 patients at an average 4.8 ± 2.6 days (range, 2-11 days) after surgery. The examiners defined ultrasound quality as "good" in 13 of 15 patients (~87%). Primary radial nerve palsy (RNP) was identified in 3 of the 15 patients, and 4 sustained secondary RNP. Nerve continuity was demonstrated by HRUS in every patient. In patients with RNP, nerve continuity was secondarily confirmed by surgical exploration or functional and electrophysiological recovery.

CONCLUSION

Early postoperative HRUS of the radial nerve after osteosynthesis of humeral shaft fractures is a feasible and reliable method to identify radial nerve continuity. In case of pathology, this assessment tool can additionally provide valuable information concerning location and etiology of the RNP.

Indications for neuromuscular ultrasound: Expert opinion and review of the literature

Over the last two decades, dozens of applications have emerged for ultrasonography in neuromuscular disorders. We wanted to measure its impact on practice in laboratories where the technique is in frequent use. After identifying experts in neuromuscular ultrasound and electrodiagnosis, we assessed their use of ultrasonography for different indications and their expectations for its future evolution. We then identified the earliest papers to provide convincing evidence of the utility of ultrasound for particular indications and analyzed the relationship of their date of publication with expert usage. We found that experts use ultrasonography often for inflammatory, hereditary, traumatic, compressive and neoplastic neuropathies, and somewhat less often for neuronopathies and myopathies. Usage significantly correlated with the timing of key publications in the field. We review these findings and the extensive evidence supporting the value of neuromuscular ultrasound. Advancement of the field of clinical neurophysiology depends on widespread translation of these findings.

[A selection of advances in neuromuscular medicine]

A selection of advances in neuromuscular medicine Abstract. Significant developments in the realm of neuromuscular medicine have occurred in both non-invasive diagnostics as well as treatments. Whole body muscle MRI can detect disease specific patterns and lead to the implementation of direct molecular genetic diagnostics. Bedside neuromuscular ultrasound can assist in diagnosing inflammatory neuropathies even in some cases enabling the omission of nerve biopsy and lumbar puncture. Specific antibodies aid in the classification and management of acquired autoimmune diseases. First effective genetic therapies for monogenetic neuromuscular illnesses are now available for spinal muscular atrophy and familial transthyretin amyloidosis. This overview aims to highlight select new diagnostic and therapeutic achievements in the realm of neuromuscular medicine.

Acute painful autoimmune neuropathy: A variant of Guillain-Barré syndrome

INTRODUCTION

We present a painful small-fiber neuropathy variant of Guillain-Barré syndrome characterized by antecedent infectious symptoms, hyporeflexia, and albuminocytologic dissociation.

METHODS

Two patients received intravenous immunoglobulin, one corticosteroids.

RESULTS

The patients subsequently improved. Immunoglobulin G (IgG) antibodies in their acute phase sera strongly bound to murine small nerve fibers, and the binding disappeared during the convalescent phase. Serum transfer to a murine nociceptive model induced transient alteration in thermal pain responses.

DISCUSSION

Our case series suggest that an acute transient immune response can be directed against small nerve fibers, and that patients so affected can exhibit features of Guillain-Barré syndrome. Muscle Nerve 57: 320-324, 2018.

Predicting treatment response in chronic, acquired demyelinating neuropathies

Chronic inflammatory demyelinating polyradiculopathy is an immune-mediated neuropathy that was first described approximately 30 years ago. Since that time an increasingly wide spectrum of chronic acquired demyelinating polyneuropathies exhibiting different phenotypes, clinical course and treatment responses to immunomodulatory treatment have been described. Several new therapeutic agents have been prescribed for such conditions, some with promising results. This review summarizes what is presently known about the clinical courses, treatment responses and predictors of response of the chronic inflammatory demyelinating polyradiculopathy subgroups.

Imaging of temperature dependent hemodynamics in the rat sciatic nerve by functional photoacoustic microscopy

Background

Vascular hemodynamics is central to the regulation of neuro-metabolism and plays important roles in peripheral nerves diseases and their prevention. However, at present there are only a few techniques capable of directly measuring peripheral nerve vascular hemodynamics.

Method

Here, we investigate the use of dark-field functional photoacoustic microscopy (fPAM) for intrinsic visualizing of the relative hemodynamics of the rat sciatic nerve in response to localized temperature modulation (i.e., cooling and rewarming).

Results and conclusion

Our main results show that the relative functional total hemoglobin concentration (HbT) is more significantly correlated with localized temperature changes than the hemoglobin oxygen saturation (SO₂) changes in the sciatic nerve. Our study also indicates that the relative HbT changes are better markers of neuronal activation than SO₂ during nerve temperature changes. Our results show that fPAM is a promising candidate for in vivo imaging of peripheral nerve hemodynamics without the use of contrast agents. Additionally, this technique may shed light on the neuroprotective effect of hypothermia on peripheral nerves by visualizing their intrinsic hemodynamics.

Imaging of the peripheral nervous system

This chapter summarizes progress in the evaluation of peripheral nerve (PN) lesions and disorders by imaging techniques encompassing magnetic resonance imaging (MRI) and nerve ultrasound (US). Due to the radiation exposure and limited sensitivity in soft tissue contrast, computed-tomography (CT) plays no significant role in the diagnostic work-up of PN disorders. MRI and US are complementary techniques for the evaluation of peripheral nerves, each having particular advantages and disadvantages. Nerve injury induces intrinsic MRI signal alterations on T2-weighted sequences in degenerating or demyelinating nerve segments as well as in corresponding muscle groups exhibiting denervation which can be exploited diagnostically. Nerve US is based on changes in the nerve echotexture due to tumor formation or focal enlargement caused by entrapment or inflammation. Both MRI and US provide morphological information on the precise site and extent of nerve injury. While US has the advantage of easy accessibility, providing images with superior spatial resolution at low cost, MRI shows better soft tissue contrast and better image quality for deep-lying nerve structures since imaging is not hindered by bone. Recent advances have remarkably increased spatial resolution of both MRI and US making imaging indispensible for the elucidation of causes of nerve compression, peripheral nerve tumors, and focal inflammatory conditions. Both MRI and US further guide neurosurgical exploration and can simplify treatment. Importantly, imaging can reveal treatable conditions even in the absence of gross electrophysiological alterations, illustrating its increasing role in clinical practice. In experimental settings, novel molecular and cellular MRI contrast agents allow in-vivo assessment of nerve regeneration as well as monitoring of neuroinflammation. Depending on further clinical development, contrast-enhanced MRI has the potential to follow cellular responses over time in vivo and to overcome the current limitations of histological assessment of nerve afflictions. Further advances in contrast-enhanced US has the potential for developing into a tool for the assessment of nerve blood perfusion, paving the way for better assessments of ischemic neuropathies.

Two randomized controlled clinical trials to study the effectiveness of prednisolone treatment in preventing and restoring clinical nerve function loss in leprosy: the TENLEP study protocols

Background

Nerve damage in leprosy often causes disabilities and deformities. Prednisolone is used to treat nerve function impairment (NFI). However, optimal dose and duration of prednisolone treatment has not been established yet. Besides treating existing NFI it would be desirable to prevent NFI. Studies show that before NFI is clinically detectable, nerves often show subclinical damage. Within the ‘Treatment of Early Neuropathy in LEProsy’ (TENLEP) study two double blind randomized controlled trials (RCT) will be carried out: a trial to establish whether prednisolone treatment of 32 weeks duration is more effective than 20 weeks in restoring nerve function in leprosy patients with clinical NFI (Clinical trial) and a trial to determine whether prednisolone treatment of early sub-clinical NFI can prevent clinical NFI (Subclinical trial).

Methods

Two RCTs with a follow up of 18 months will be conducted in six centers in Asia. In the Clinical trial leprosy patients with recent (< 6 months) clinical NFI, as determined by Monofilament Test and Voluntary Muscle Test, are included. The primary outcomes are the proportion of patients with restored or improved nerve function. In the Subclinical trial leprosy patients with subclinical neuropathy, as determined by Nerve Conduction Studies (NCS) and/or Warm Detection Threshold (WDT), and without any clinical signs of NFI are randomly allocated to a placebo group or treatment group receiving 20 weeks prednisolone. The primary outcome is the proportion of patients developing clinical NFI. Reliability and normative studies are carried out before the start of the trial.

Discussion

This study is the first RCT testing a prednisolone regimen with a duration longer than 24 weeks. Also it is the first RCT assessing the effect of prednisolone in the prevention of clinical NFI in patients with established subclinical neuropathy. The TENLEP study will add to the current understanding of neuropathy due to leprosy and provide insight in the effectiveness of prednisolone on the prevention and recovery of NFI in leprosy patients. In this paper we present the research protocols for both Clinical and Subclinical trials and discuss the possible findings and implications.

Trial registration

Netherlands Trial Register: NTR2300

Clinical Trial Registry India: CTRI/2011/09/002022

Complex partial status epilepticus associated with adult H1N1 infection

In the wake of the worldwide H1N1 pandemic, there has been evidence that the H1N1 influenza virus is associated with neurological complications. This is the first report describing status epilepticus in an adult patient with H1N1 virus infection, to our knowledge. This patient had no prior history of epilepsy and presented with complex partial status epilepticus. This was further illustrated on electroencephalographs and MRI brain changes that corresponded with the patient's clinical state and which subsequently resolved on follow-up. Although uncommon, H1N1 infections may result in central nervous system complications in adults and it is crucial to treat such patients with urgency.

Trapezius motor evoked potential in evaluations of corticospinal tract lesions

BACKGROUND

We wanted to know whether trapezius motor evoked potentials (MEPs) are helpful in the evaluation of corticospinal (CS) lesions above the fifth cervical segment (C5) and compared trapezius MEP measurements in patients with and without radiological evidence of CS lesions.

METHODS

Trapezius MEPs were routinely recorded in all MEP studies performed in our hospital. Patients who had MEP studies as well as brain and cervical spine imaging were retrospectively assigned to two groups. Group 1 had radiological evidence of CS lesion above the level of C5 whilst group 2 did not.

RESULTS

Forty-nine patients were included in the study. Twenty-eight patients were assigned to group 1 and 21 patients to group 2. The frequencies of abnormal values in the two groups were compared. Twelve (43%) patients in group 1 and three (14%) in group 2 had prolonged MEP latencies. Thirteen patients in group 1 had indentation or impingement of the cervical cord by intervertebral discs as the only relevant radiological abnormality. Seven (54%) of these patients were found to have prolonged trapezius MEP latencies, providing functional correlates to the radiological abnormalities.

CONCLUSIONS

Our study gives evidence to the usefulness of trapezius MEP study in the evaluation of CS lesions.

Electroencephalographic changes and seizures in familial hemiplegic migraine patients with the CACNA1A gene S218L mutation

The S218L CACNA1A mutation has been previously described in two families with familial hemiplegic migraine. We present three siblings with the mutation with the novel association of childhood seizures, and highlight the dynamic changes seen on electroencephalography during hemiplegic migraine attacks. Depressed activity contralateral to the hemiparesis was seen on electroencephalography during acute hemiplegic migraine attacks, which may be due to changes to calcium channels caused by the S218L mutation. Both parents were asymptomatic and did not carry the S218L mutation in their blood. This suggests the presence of mosaicism in the transmitting parent.

A novel methodology to probe endothelial differential gene expression profile reveals novel genes

Endothelial dysfunction is a major feature of vascular diseases. A practical, minimally invasive method to effectively "probe" gene transcription for an individual patient's endothelium has potential to "customize" assessment for an individual at risk of vascular disease as well as pathophysiologic insight in an in vivo human, clinical context. Published literature lacks a methodology to identify endothelial differential gene expression in individuals with vascular disease. We describe a methodology to do so. The aim of this study was to specifically utilize (a) cutaneous microvascular biopsy, (b) laser capture microdissection, (c) cDNA amplification, (d) suppression subtractive hybridization, (e) high-throughput sequencing techniques, (f) real-time polymerase chain reaction (PCR), and (g) in combination of these methods, to profile differential gene expression in the context of cardiovascular and cerebrovascular disease. Endothelial cells were obtained by laser capture microdissection from a patient and a healthy sibling's microvascular biopsy tissues. Endothelial RNA was extracted, reverse transcribed, and amplified to ds cDNA. Suppression subtractive hybridization was used to establish an endothelial differential gene expression library. Real-time PCR confirmed SERP1, caspase 8, IGFBP7, S100A4, F85, and F147 up-regulation between 1.4- and 3.47-fold. The authors have successfully established a methodology to profile endothelial differential gene expression and identified six differentially expressed genes. This minimally invasive novel method has potential wide application in the customized assessment of many patients suffering vascular diseases.

Melkerrson-Rosenthal syndrome with cardiac involvement

Melkerrson-Rosenthal syndrome (MRS) is a granulomatous disease usually restricted to the orofacial region. We report a case of MRS in a 37-year-old Malay patient who presented with complete heart block on a background of recurrent oro-facial swelling and facial diplegia. Lip biopsy showed lymphohistocytic granulomatous inflammation typical for MRS. Extensive work-up excluded other causes of the complete heart block. To our knowledge, this is the first reported case of MRS affecting cardiac connective tissues and the first report of MRS in an ethnic Malay. We postulate granulomatous infiltration of the conductive tissues as the basis for the heart block. Another unusual feature of the case was the presence of left eye abduction limitation.

The INFIR Cohort Study: assessment of sensory and motor neuropathy in leprosy at baseline

AIM

To compare different method(s) to detect peripheral neuropathy in leprosy and to study the validity of the monofilament test (MF) and the voluntary muscle test (VMT) as standard tests of nerve function.

DESIGN

A multi-centre cohort study of 303 multibacillary (MB) leprosy patients.

METHODS

Newly registered MB patients requiring a full course of MDT were recruited in two leprosy outpatient clinics in North India. Controls were people without leprosy or neurological conditions, attending the dermatological outpatient departments of the same clinics. Nerve function was evaluated electrophysiologically using standard parameters for sensory and motor nerve conduction (NC) testing, warm and cold detection thresholds (W/CDT), vibration perception thresholds, dynamometry, MF and VMT. The latter two defined the outcomes of sensory and motor impairment.

RESULTS

115 patients had nerve damage or a reaction of recent onset at diagnosis. Sensory and motor amplitudes and WDTs were the most frequently abnormal. Among the nerves tested, the sural and posterior tibial were the most frequently impaired. In the ulnar nerve, sensory latencies were abnormal in 25% of subjects; amplitudes in 40%. Ulnar above-elbow motor conduction velocities were abnormal in 39% and amplitudes 32%. WDTs were much more frequently affected than CDTs in all nerves tested. The thresholds of all test parameters differed significantly between controls and patients, while only some differed between patients with and without reaction. Good concordance was observed between MF results and sensory latencies and velocities (direct concordance 80% for the ulnar). However, a proportion of nerves with abnormal MF results tested normal on one or more of the other tests or vice versa. Concordance between VMT and motor conduction velocities was good for the ulnar nerve, but for the median and peroneal nerves, the proportion impaired by VMT out of those with abnormal motor conduction was very low.

CONCLUSIONS

Concordance between monofilaments and other sensory function test results was good, supporting the validity of the monofilaments as standard screening test of sensory function. Concordance between VMT results and motor nerve conduction was good for the ulnar nerve, but very few median and peroneal nerves with abnormal conduction had an abnormal VMT. A more sensitive manual motor test may be needed for these nerves. Of the nerve assessment tests conducted, NC amplitudes and warm sensation were the most frequently affected. Therefore, nerve conduction studies and WDT measurements appear to be most promising tests for early detection of leprous neuropathy. The pattern of concordance between tactile and thermal sensory impairment failed to support the hypothesis that small fibre neuropathy always precedes large fibre damage. Warm sensation was more frequently affected than cold sensation. This could indicate that unmyelinated C fibres are more frequently affected than small myelinated Asigma fibres.

Frequency of provocative factors in epileptic patients admitted for seizures: A prospective study in Singapore

Intractable epilepsy is commonly believed to be the main cause of uncontrolled seizures and hospitalization in epileptic patients. We study frequency and types of potential provocative factors in epileptic patients admitted with seizures, and suggest methods to decrease seizure occurrence and hospitalization. Over 6 months we prospectively studied all epileptic patients hospitalized for seizures. A structured interview and laboratory investigations were used to determine type and number of potential seizure precipitants. Precipitants thought to be avoidable through actions taken by the patient or physicians were termed potentially preventable provocative factors (PPPF). Patients' awareness and knowledge of seizure precipitants were also assessed. Three quarters of all seizures leading to admission were associated with PPPF, the commonest being non-compliance (71%), sub-therapeutic doses of antiepileptic drugs (26%) and sleep deprivation (9%). Only one patient had intractable epilepsy. Patients' knowledge of seizure precipitants was poor. The majority of hospital admissions for seizures in epileptic patients are associated with potentially preventable causes amenable to education programmes. Patient education involving epilepsy nurse educators may play an important role in decreasing seizure occurrence and possibly unnecessary hospital admissions.

Adult-onset re-emergent stuttering as a presentation of Parkinson's disease

INTRODUCTION

The basal ganglia-thalamocortical motor circuits are postulated to play a key role in the aetiopathogenesis of stuttering. The main dysfunction is thought to be an impairment in the ability of the basal ganglia to produce timing cues for the initiation of the next motor segment of speech, explaining the association of acquired and re-emergent stuttering with diseases such as dystonia and Parkinson's disease.

CLINICAL PICTURE

We describe a 61-year-old man presenting with re-emergent stuttering and mild hypomimia, only to develop unilateral rest tremors, hypo- and bradykinesia, rigidity and gait difficulties one year later.

TREATMENT AND OUTCOME

His parkinsonism responded well to treatment with bromocriptine, but he continued to stutter.

DISCUSSION

This case illustrates the association between acquired or re-emergent stuttering and basal ganglia disorders, and highlights the need to assess such patients for an underlying aetiology.

Paraneoplastic progressive supranuclear palsy syndrome in a patient with B-cell lymphoma

An important component in the diagnosis of atypical parkinsonian disorders is the exclusion of secondary causes. Paraneoplastic causes of parkinsonism are extremely rare. We describe a case which presented initially as probable progressive supranuclear palsy (PSP) but on follow-up displayed a rapidly progressive course, unexplained fever, peripheral neuropathy and an abnormal CSF. We highlight the difficulties faced in formulating a diagnosis for this unusual case prior to the discovery of an occult B-cell lymphoma, and discuss its relevance in the exclusion criteria for PSP. A paraneoplastic cause should be considered if disease progression is unusually rapid.