Diagnosis and treatment of chronic inflammatory demyelinating polyradiculoneuropathy in clinical practice: A survey among Dutch neurologists.

The diagnosis and treatment of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is often a challenge. The clinical presentation is diverse, accurate biomarkers are lacking, and the best strategy to initiate and maintain treatment is unclear. The aim of this study was to determine how neurologists diagnose and treat CIDP. We conducted a cross-sectional survey on diagnostic and treatment practices among Dutch neurologists involved in the clinical care of CIDP patients. Forty-four neurologists completed the survey (44/71; 62%). The respondents indicated to use the European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) 2010 CIDP guideline for the diagnosis in 77% and for treatment in 50%. Only 57% of respondents indicated that the presence of demyelinating electrophysiological findings was mandatory to confirm the diagnosis of CIDP. Most neurologists used intravenous immunoglobulins (IVIg) as first choice treatment, but the indications to start, optimize, or withdraw IVIg, and the use of other immune-modulatory therapies varied. University-affiliated respondents used the EFNS/PNS 2010 diagnostic criteria, nerve imaging tools, and immunosuppressive drugs more often. Despite the existence of an international guideline, there is considerable variation among neurologists in the strategies employed to diagnose and treat CIDP. More specific recommendations regarding: (a) the minimal set of electrophysiological requirements to diagnose CIDP, (b) the possible added value of nerve imaging, especially in patients not meeting the electrodiagnostic criteria, (c) the most relevant serological examinations, and (d) the clear treatment advice, in the new EFNS/PNS guideline, would likely support its implementation in clinical practice.

Assessment of the reliability of the motor unit size index (MUSIX) in single subject "round-robin" and multi-centre settings.

OBJECTIVE: The motor unit size index (MUSIX) is incorporated into the motor unit number index (MUNIX). Our objective was to assess the intra-/inter-rater reliability of MUSIX in healthy volunteers across single subject "round robin" and multi-centre settings. METHODS: Data were obtained from (i) a round-robin assessment in which 12 raters (6 with prior experience and 6 without) assessed six muscles (abductor pollicis brevis, abductor digiti minimi, biceps brachii, tibialis anterior, extensor digitorum brevis and abductor hallucis) and (ii) a multi-centre study with 6 centres studying the same muscles in 66 healthy volunteers. Intra/inter-rater data were provided by 5 centres, 1 centre provided only intra-rater data. Intra/inter-rater variability was assessed using the coefficient of variation (COV), Bland-Altman plots, bias and 95% limits of agreement. RESULTS: In the round-robin assessment intra-rater COVs for MUSIX ranged from 7.8% to 28.4%. Inter-rater variability was between 7.8% and 16.2%. Prior experience did not impact on MUSIX values. In the multi-centre study MUSIX was more consistent than the MUNIX. Abductor hallucis was the least reliable muscle. CONCLUSIONS: The MUSIX is a reliable neurophysiological biomarker of reinnervation. SIGNIFICANCE: MUSIX could provide insights into the pathophysiology of a range of neuromuscular disorders, providing a quantitative biomarker of reinnervation.

Implementing Motor Unit Number Index (MUNIX) in a large clinical trial: Real world experience from 27 centres.

OBJECTIVE: Motor Unit Number Index (MUNIX) is a quantitative neurophysiological method that reflects loss of motor neurons in Amyotrophic Lateral Sclerosis (ALS) in longitudinal studies. It has been utilized in one natural history ALS study and one drug trial (Biogen USA) after training and qualification of raters. METHODS: Prior to testing patients, evaluators had to submit test-retest data of 4 healthy volunteers. Twenty-seven centres with 36 raters measured MUNIX in 4 sets of 6 different muscles twice. Coefficient of variation of all measurements had to be <20% to pass the qualification process. MUNIX COV of the first attempt, number of repeated measurements and muscle specific COV were evaluated. RESULTS: COV varied considerably between raters. Mean COV of all raters at the first measurements was 12.9% ±â€¯13.5 (median 8.7%). Need of repetitions ranged from 0 to 43 (mean 10.7 ±â€¯9.1, median 8). Biceps and first dorsal interosseus muscles showed highest repetition rates. MUNIX variability correlated considerably with variability of compound muscle action potential. CONCLUSION: MUNIX revealed generally good reliability, but was rater dependent and ongoing support for raters was needed. SIGNIFICANCE: MUNIX can be implemented in large clinical trials as an outcome measure after training and a qualification process.

Nerve ultrasound in polyneuropathies.

Ultrasound can be used to visualize pathology in the peripheral nerves of patients with polyneuropathy. Nerve enlargement is the most frequent pathology, but other abnormalities, including abnormal nerve echogenicity and vascularity, are also encountered. This monograph presents an overview of the role of nerve ultrasound in the evaluation and management of both inherited and acquired polyneuropathies. A description of the sonographic techniques and common abnormalities is provided, followed by a presentation of typical findings in different neuropathies. Scoring systems for characterizing the presence and pattern of nerve abnormalities as they relate to different polyneuropathies are presented. Muscle Nerve 57: 716-728, 2018.

Quality Control of Motor Unit Number Index (MUNIX) Measurements in 6 Muscles in a Single-Subject "Round-Robin" Setup.

BACKGROUND: Motor Unit Number Index (MUNIX) is a neurophysiological measure that provides an index of the number of lower motor neurons in a muscle. Its performance across centres in healthy subjects and patients with Amyotrophic Lateral Sclerosis (ALS) has been established, but inter-rater variability between multiple raters in one single subject has not been investigated. OBJECTIVE: To assess reliability in a set of 6 muscles in a single subject among 12 examiners (6 experienced with MUNIX, 6 less experienced) and to determine variables associated with variability of measurements. METHODS: Twelve raters applied MUNIX in six different muscles (abductor pollicis brevis (APB), abductor digiti minimi (ADM), biceps brachii (BB), tibialis anterior (TA), extensor dig. brevis (EDB), abductor hallucis (AH)) twice in one single volunteer on consecutive days. All raters visited at least one training course prior to measurements. Intra- and inter-rater variability as determined by the coefficient of variation (COV) between different raters and their levels of experience with MUNIX were compared. RESULTS: Mean intra-rater COV of MUNIX was 14.0% (±6.4) ranging from 5.8 (APB) to 30.3% (EDB). Mean inter-rater COV was 18.1 (±5.4) ranging from 8.0 (BB) to 31.7 (AH). No significant differences of variability between experienced and less experienced raters were detected. CONCLUSION: We provide evidence that quality control for neurophysiological methods can be performed with similar standards as in laboratory medicine. Intra- and inter-rater variability of MUNIX is muscle-dependent and mainly below 20%. Experienced neurophysiologists can easily adopt MUNIX and adequate teaching ensures reliable utilization of this method.

Distinctive patterns of sonographic nerve enlargement in Charcot-Marie-Tooth type 1A and hereditary neuropathy with pressure palsies.

OBJECTIVE: The extent of sonomorphologic differences of peripheral nerves between CMT and HNPP is unknown. METHODS: We recruited 9 patients with CMT-1A and 9 with HNPP. Patients underwent a standardized sonographic protocol, which evaluated nerve size and vascularization. We quantitatively assessed fascicle size and echogenicity. RESULTS: All 18 patients demonstrated nerve enlargement, but no increased vascularization. HNPP demonstrated larger nerves at sites of entrapment (median nerve at the carpal tunnel p=0.049, ulnar nerve at the sulcus p<0.001), greater swelling ratios of median (p<0.001), ulnar (p=0.017) and fibular nerve (p=0.005) than CMT-1A. CMT-1A revealed larger nerves proximal to sites of entrapment (median and fibular nerve, brachial plexus p<0.001). Nerve fascicles where larger (p<0.001) and more hypo-echogenic in CMT-1A. Nerve, fascicle size nor echogenicity correlated with age, gender or MRC sum-score. CONCLUSIONS: Ultrasonography of nerves reveals specific phenotypes differentiating CMT-1A from HNPP. In CMT-1A enlargement of nerves and fascicles is multifocal among multiple nerves, whereas in HNPP nerve enlargement is restricted to sites of entrapment. SIGNIFICANCE: Our findings of specific sonomorphological phenotypes, differentiating CMT-1A from HNPP, may help to improve our pathophysiological insights in CMT and HNPP.

Ischaemic stroke as initial presentation of systemic malignancy.

Ischaemic stroke as the initial presentation of systemic malignancy is reported infrequently and is characterised by ischaemic lesions that exceed the vascular territory of a single vessel. There is also a high rate of early stroke recurrence. Several pathophysiological mechanisms are known to cause cerebrovascular complications in malignancies, as a direct effect of the tumour, paraneoplastic or even of the tumour treatment itself. Prognosis is reportedly poor, treatment is symptomatic and at best anecdotal. We present a case report and available literature.

Corticosteroid treatment buys time in case of a newly diagnosed hypophysitis with visual deterioration.

Hypophysitis is an important differential diagnosis for a pituitary mass, especially in young women at the end of or shortly after pregnancy. It commonly results in hypopituitarism and can be differentiated from adenoma on MRI. Typical MRI characteristics of hypophysitis are symmetry, loss of posterior bright spot, intense and homogeneous gadolinium enhancement, a thickened pituitary stalk and intact sellar floor. Treatment of choice in the acute phase of a hypophysitis is corticosteroids. Adequate corticosteroid treatment may effectively buy time and avoid unnecessary surgical treatment and is related to further decrease of pituitary function, even in progressive cases of deterioration due to compression of the chiasm. Strict monitoring of the vision and a control MRI is obligatory to evaluate the treatment after 48-36 h. Tissue diagnosis is mandatory when there are multiple relapses. We present a case of progressive visual deterioration in hypophysitis, successfully treated with high-pulse dose prednisolone.

Temporary recovery after resuscitation: delayed postanoxic encephalopathy.

Delayed postanoxic encephalopathy is reported infrequently and is characterised by a lucid interval of seemingly good recovery from an anoxic insult. Days or even weeks may pass before changes in behaviour, motor responses or consciousness occur. Neurological deterioration may progress to coma, death or severe disability, whereas some patients have a second recovery period. Pathogenesis is yet to be discovered. Prognosis is reportedly poor, treatment is symptomatic and at best anecdotal. We present a case report and available literature.