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Biomedical subjects

Gerald J D Hengstman

Publications and source records attributed to Gerald J D Hengstman.

12 recordsLinked to original sources

Needle electromyographic findings in 98 patients with myositis.

BACKGROUND/AIMS: Little is known about the distribution of electromyographic (EMG) abnormalities in myositis even though this is relevant in daily practice. METHODS: A retrospective semiquantitative analysis of needle EMG findings was performed in a group of 98 patients with myositis. The frequency, type, and distribution of abnormalities were studied. The influence of the use of corticosteroids and the stage of the disease were evaluated. RESULTS: In most patients, a myopathic pattern with spontaneous activity was found, although several clinically relevant exceptions were noted. Long-duration motor unit potentials were found in all three diagnostic groups and were not associated with disease duration. In the lower extremity a distal to proximal gradient was present, adding to the diagnostic confusion with neurogenic diseases, and spontaneous activity was absent in a relatively large group although none of the patients in the acute stage of the disease had a normal EMG. The use of corticosteroids reduced the number of abnormal findings in dermatomyositis and polymyositis, but not in inclusion body myositis. CONCLUSION: A myopathic pattern with spontaneous activity was most frequently found, although several clinically relevant exceptions were noted. These results illustrate the spectrum of EMG findings in myositis, and may aid the clinician in the interpretation of the EMG in these patients.

Arm↗

Delayed cranial neuropathy after neurosurgery caused by herpes simplex virus reactivation: report of three cases.

BACKGROUND: Delayed cranial neuropathy is an uncommon complication of neurosurgical interventions of which the exact etiology is uncertain. Several authors have hypothesized that reactivation of herpesviruses may play a role. CASE DESCRIPTIONS: The first patient underwent microvascular decompression of the left facial nerve because of hemifacial spasm. Nine days postoperatively, he developed severe facial weakness on the ipsilateral side. The polymerase chain reaction for herpes simplex virus (HSV) was positive in the cerebrospinal fluid (CSF). Treatment with intravenous acyclovir was initiated, after which a rapid and marked improvement was observed. The second patient developed left-sided facial numbness 20 days after microvascular decompression of the left facial nerve. The polymerase chain reaction for HSV was positive in the CSF. Treatment with intravenous acyclovir resulted in full recovery. The third patient underwent a suboccipital craniectomy with excision of a meningioma located at the left petrosal apex. Three months postoperatively, she developed multiple cranial neuropathies (involving cranial nerves V, VI, VIII, and XII). This was accompanied by serologic evidence of HSV reactivation and a positive polymerase chain reaction for HSV in the CSF. The patient was successfully treated with intravenous acyclovir. CONCLUSIONS: The 3 reported cases provide evidence that delayed postoperative cranial neuropathy can be caused by HSV reactivation and can involve multiple cranial nerves. An increased awareness of this treatable postoperative complication is warranted.

Adult↗

Muscle-fiber conduction velocity and electromyography as diagnostic tools in patients with suspected inflammatory myopathy: a prospective study.

Combinations of different techniques can increase the diagnostic yield from neurophysiological examination of muscle. In 25 patients with suspected inflammatory myopathy, we prospectively performed needle electromyography (EMG) and measured muscle-fiber conduction velocity (MFCV) in a single muscle, using a technique with direct muscle-fiber stimulation and recording. Results of MFCV were compared with final diagnosis, EMG, and needle muscle biopsy. Diagnostic accuracy of combined MFCV and EMG studies was 72%, compared to 60% for EMG alone. This improvement was due to a gain in specificity. The MFCV did not prove useful in discriminating inflammatory myopathy from other myopathies. Furthermore, we found a correlation of 92% between variability of MFCV and myopathic changes in muscle biopsy. We conclude that the utility of electrodiagnostic examination can be increased if EMG examination is combined with MFCV studies.

Action Potentials↗

Myositis specific autoantibodies: changing insights in pathophysiology and clinical associations.

PURPOSE OF REVIEW: Defined autoantibodies are found in about half of the patients with myositis. Traditionally, these autoantibodies have been divided into myositis specific autoantibodies (MSAs) and myositis associated autoantibodies. Several studies have shown that MSAs are associated with specific clinical characteristics and can aid our understanding of the pathophysiology of myositis. RECENT FINDINGS: Recent studies suggest that some MSAs are markers of specific inflammatory muscle diseases (e.g., anti-SRP for an immune-mediated necrotizing myopathy) and not just of myositis in general. Furthermore, new insights are emerging about the pathophysiology of MSAs, in particular anti-Jo-1. Based on these new insights, an alternative hypothesis of the formation of anti-Jo-1 autoantibodies is presented in which the immune system itself rather than muscle is the site of antigen presentation. SUMMARY: The recognition that some MSAs are markers of specific disease entities that were once commonly referred to as (poly)myositis, aids the development of better disease definitions. The changing insights in the function of the Jo-1 antigen and the emergence of new hypotheses on the formation of the Jo-1 antibody, open new avenues for future research aimed at unraveling the mystery of myositis.

Antibody Specificity↗

Concomitant dermatomyositis and myasthenia gravis presenting with respiratory insufficiency.

We report a 28-year-old woman with a history of chronic immune-mediated hepatitis, in whom the simultaneous manifestation of dermatomyositis and myasthenia gravis resulted in severe neck extensor weakness and subacute respiratory insufficiency, followed by proximal muscle weakness and external ophthalmoplegia. Radiological signs of a thymoma were absent. The distinguishing clinical, electrophysiological, and biopsy findings are discussed. We suggest that an underlying immunoregulatory disorder was present, explaining the occurrence of three rare immune-mediated diseases in one patient.

Adult↗

Autoantibodies directed to novel components of the PM/Scl complex, the human exosome.

The autoantigenic polymyositis/scleroderma (PM/Scl) complex was recently shown to be the human homologue of the yeast exosome, which is an RNA-processing complex. Our aim was to assess whether, in addition to targeting the known autoantigens PM/Scl-100 and PM/Scl-75, autoantibodies also target recently identified components of the PM/Scl complex. The prevalence of autoantibodies directed to six novel human exosome components (hRrp4p, hRrp40p, hRrp41p, hRrp42p, hRrp46p, hCsl4p) was determined in sera from patients with idiopathic inflammatory myopathy (n = 48), scleroderma (n = 11), or the PM/Scl overlap syndrome (n = 10). The sera were analyzed by enzyme-linked immunosorbent assays and western blotting using the affinity-purified recombinant proteins. Our results show that each human exosome component is recognized by autoantibodies. The hRrp4p and hRrp42p components were most frequently targeted. The presence of autoantibodies directed to the novel components of the human exosome was correlated with the presence of the anti-PM/Scl-100 autoantibody in the sera of patients with idiopathic inflammatory myopathy (IIM), as was previously found for the anti-PM/Scl-75 autoantibody. Other clear associations between autoantibody activities were not found. These results further support the conception that the autoimmune response may initially be directed to PM/Scl-100, whereas intermolecular epitope spreading may have caused the autoantibody response directed to the associated components.

Autoantibodies↗