Limb motor nerve dysfunction in Miller Fisher syndrome

Typical Miller Fisher syndrome (MFS) lacks limb muscle weakness, but some patients may unpredictably progress to severe Guillain‐Barré syndrome. The compound muscle action potential (CMAP) scan is a recently developed non‐invasive, painless, and reproducible method for detecting early changes in motor nerve excitability. This technique was used to monitor subclinical limb motor nerve dysfunction during disease course in typical MFS. Three Miller Fisher patients with preserved limb muscle strength and normal routine nerve conduction studies were included. Frequent serial CMAP scanning of the median nerve was performed during acute phase and follow‐up and was related to clinical course and outcome. All patients showed an abnormal increase in the range of stimulus intensities at the day of hospital admission, indicating reduced motor nerve excitability already at the earliest stage of disease. Median nerve dysfunction progressed in parallel or even before clinical deterioration, and improved with clinical recovery. Our study shows that typical MFS is a more general neuropathy, affecting peripheral motor nerves even in patients with preserved limb strength and conduction velocity. CMAP scanning is a sensitive technique for early detection of subclinical motor nerve dysfunction and for monitoring disease activity in immune‐mediated neuropathies.     

Diagnostic nerve ultrasound in Charcot–Marie–Tooth disease type 1B

Ultrasound is emerging as a useful tool for evaluation of neuromuscular conditions, because it can provide high‐resolution anatomic information to complement electrodiagnostic data. There have been few studies in which ultrasound was used to assess the peripheral nerves of individuals with Charcot–Marie–Tooth (CMT) disease and none involving CMT type 1B. In this study we compared nerve cross‐sectional area in individuals from a single large family with CMT 1B with normal, healthy controls. We also assessed for cranial nerve enlargement in those with CMT 1B with cranial neuropathies compared to those with CMT 1B without cranial neuropathies. Individuals with CMT 1B have significantly larger median and vagus nerves than healthy controls, but no difference was seen in cranial nerve size between those with versus those without cranial neuropathies. This is the first study to characterize the ultrasonographic findings in the peripheral nerves of individuals with CMT 1B. Muscle Nerve 40: 98–102, 2009     

MRI findings of optic pathway involvement in Miller Fisher syndrome in 3 pediatric patients and a review of the literature

Background: Miller Fisher syndrome (MFS) is a rare demyelinating condition which may have involvement of cranial nerves. There are a few case reports of optic pathway involvement in children. We describe 3 patients with optic pathway enhancement in pediatric patients with MFS. Case series: We retrospectively reviewed brain imaging findings in 17 pediatric patients with of Guillain–Barré syndrome (GBS) meeting Brighton criteria who had brain MRIs performed during their acute illness. Cranial nerve enhancement was seen in 6/17 patients and optic nerve/chiasm enhancement was seen in 3 patients. Conclusion: Cranial nerve enhancement and optic pathway in particular, can be seen in patients with MFS. Imaging findings do not always correlate with clinical manifestations of cranial nerve involvement.     

Multifocal,hypoechogenic nerve thickening in Cerebrotendinous Xanthomatosis

ObjectiveTo characterize peripheral nerve morphology in cerebrotendinous xanthomatosis (CTX) patients using high-resolution ultrasound (HRUS) in vivo. We hypothesized that nerve enlargements might be present in CTX as a result of accumulation of abnormal lipids with deposition also in peripheral nerves.MethodsFour CTX patients were examined using HRUS to assess morphological abnormalities of peripheral nerves as well as cervical nerve roots 5 and 6.ResultsHRUS revealed mild to moderate, hypoechogenic thickening of sensorimotor nerves (ulnar nerve in 1/4, tibial nerve in 3/4, median nerve 4/4 patients) as well as mild enlargement of pure sensory nerves (sural nerve in 2/3, superficial FN in 2/4 patients). The vagal nerve was moderately enlarged in one patient, cervical roots showed moderate enlargements of C5 in two patients, one of which also showing thickening of C6 as well as in another patient. UPSS score was slightly to moderately abnormal in all patients. The Homogeneity score was not increased suggesting regional to inhomogeneous nerve enlargement.ConclusionsHRUS shows multifocal, hypoechogenic nerve thickening of peripheral nerves and nerve roots in CTX.SignificanceHRUS might serve as a valuable, additive and non-invasive bedside tool to assess peripheral nerve morphology in future clinical studies on CTX patients.     

High‐resolution ultrasound visualization of the subcutaneous nerves of the forearm: A feasibility study in anatomic specimens

Introduction: The aim of this ultrasound‐anatomical study was to evaluate the ability of high‐resolution ultrasound (HRUS) to visualize and infiltrate small subcutaneous nerves of the forearm in anatomic specimens. Methods: Seven nonembalmed human bodies (4 men, 3 women; mean age at death, 60 years) were included in the study. Two investigators scanned the anatomic specimens using 15‐MHz and 18‐MHz HRUS transducers. The lateral, medial, and posterior antebrachial cutaneous nerves were scanned and interventionally marked with ink using HRUS‐guidance. Subsequently, dissections were performed to assess the anatomical correlation of HRUS findings. Results: All 3 nerves were identified consistently using HRUS. The precision of the ink‐markings was excellent, with good correlation with the small peripheral branches of all 3 nerves. Conclusions: HRUS can identify precisely the small subcutaneous nerves of the forearm and may aid in both diagnosis and therapy in cases of neuropathy. Muscle Nerve 49 : 676–679, 2014     

Entrapment syndrome of multiple nerves in graft‐versus‐host disease

Introduction: Peripheral nerve entrapment syndromes are associated with hereditary neuropathy with liability to pressure palsies and a variety of rheumatic and endocrinological diseases. Methods: We report a patient with entrapment syndromes of multiple nerves associated with chronic graft‐versus‐host‐disease (GVHD) after allogeneic hematopoietic stem cell transplantation. Nerve ultrasound, histology, and ultrastructural changes were assessed. Results: The 51‐year‐old man had developed severe deep dermal sclerosis due to chronic GVHD with a progressive polyneuropathy and entrapment syndromes of multiple nerves. Pre‐stenotic enlargement was shown by nerve ultrasound. Histology demonstrated fibrosis of the epineurium with scarce infiltration of macrophages. Electron microscopy demonstrated alterations of the myelin sheaths and marked depletion of normal‐sized myelinated nerve fibers. Conclusions: In addition to polyneuropathy, chronic GVHD can be associated with peripheral nerve entrapment syndromes and should be added to the differential diagnosis of compressive neuropathies. Muscle Nerve 49 : 138–142, 2014     

High-resolution ultrasound in patients with Wartenberg’s migrant sensory neuritis,a case-control study

Objective

Wartenberg’s migrant sensory neuritis (WMSN) is a rare, patchy, pure sensory neuropathy of unknown etiology. High-resolution ultrasonography (HRUS) is an emerging diagnostic technique for neuropathies, but it has not been applied in WMSN. In this study we aimed to determine HRUS abnormalities in WMSN.

Neuroimaging of classic neuralgic amyotrophy

Introduction: Neuralgic amyotrophy (NA) often imposes diagnostic problems. Recently, MRI and high‐resolution ultrasound (HRUS) have proven useful in diagnosing peripheral nerve disorders. Methods: We performed a chart and imaging review of patients who were examined using neuroimaging and who were referred because of clinically diagnosed NA between March 1, 2014 and May 1, 2015. Results: Six patients were included. All underwent HRUS, and 5 underwent MRI. Time from onset to evaluation ranged from 2 weeks to 6 months. HRUS showed segmental swelling of all clinically affected nerves/trunks. Atrophy of muscles was detected in those assessed >1 month after onset. MRI showed T2‐weighted hyperintensity in all clinically affected nerves, except for the long thoracic nerve, and denervation edema of muscles. Conclusions: HRUS and MRI are valuable diagnostic tools in NA. This could change the diagnostic approach from one now focused on excluding other disorders to confirming NA through imaging markers. Muscle Nerve 54 : 1079–1085, 2016     

Involvement of the central nervous system in Miller Fisher syndrome: a case report

Miller Fisher syndrome (MFS) is characterised by ophthalmoplegia, ataxia and areflexia. Reports on cerebellar ataxia and supranuclear oculomotor derangement in MFS suggested an additional involvement of the central nervous system (CNS), resembling Bickerstaff's brainstem encephalitis (BBE). In the present report, a patient with a monophasic acute illness, early recovery and specific clinical-laboratory findings suggested both intrinsic brainstem and peripheral nerve disease (MFS and BBE). In pons and medulla oblangata, blurred to discrete T2-lesions were revealed by cranial MRI, while involvement of peripheral nerves was detected with EMG. The CSF showed no increase in protein or cell content, such as occurs in brainstem encephalitis.     

Giant nerves in chronic inflammatory polyradiculoneuropathy

Introduction: Nerve enlargement (NE) is described in inflammatory and inherited neuropathies. It is commonly multifocal and moderate in the former and homogeneous and generalized in the latter. We describe 4 cases of massive NE in inflammatory neuropathies. Methods: Patients presented with symptoms of polyneuropathy that progressed over months to years. Nerve conduction studies (NCS), laboratory analysis, nerve MRI, and nerve ultrasound were performed. Results: NCS revealed demyelinating neuropathy in all with multifocal conduction blocks or increased terminal latency indices. MRI/ultrasound revealed extensive NE in the roots and nerves. Detailed diagnostics including biopsies, positron emission tomography‐computed tomography, and genetic testing revealed no other pathology. Chronic inflammatory demyelinating polyneuropathy variants were diagnosed in all, and immunotherapies were successfully initiated. Conclusions: MRI and ultrasound contributed to diagnosis and therapy. All patients had giant NE in common, which strongly suggested inherited neuropathy. However, the final diagnosis was inflammatory neuropathy. Impressive NE can occur in immune‐mediated neuropathies and should be carefully differentiated from inherited neuropathies. Muscle Nerve 55 : 285–289, 2017     

Proximal conduction block in the pharyngeal–cervical–brachial variant of guillain–barrÉ syndrome

Introduction: Conduction block (CB) has been included in the Rajabally criteria for axonal Guillain–Barré syndrome (GBS). Because the nerve roots may be affected early in GBS, detection of proximal CB by the triple stimulation technique (TST) can be useful. Methods: We describe TST findings in 2 patients who presented with the pharyngeal–cervical–brachial (PCB) variant of axonal GBS. Results: In the first patient, although conventional nerve conduction studies (NCS) did not fit electrodiagnostic criteria for axonal GBS, the TST detected proximal CB in the median and ulnar nerves. In the second patient, NCS fulfilled criteria for axonal GBS, and the TST detected proximal CB in the median nerve. After plasmapheresis, NCS and TST findings were normalized, suggesting reversible conduction failure rather than demyelinating CB. Conclusion: The TST may be useful for diagnosis of PCB when NCS remain inconclusive. The technique provides additional clues for classifying PCB into the acute nodo‐paranodopathies. Muscle Nerve 52 : 1102–1106, 2015     

Nerve high-resolution ultrasonography in tangier disease

Introduction: Tangier disease (TD) is an autosomal recessive disorder characterized by severe reduction in high-density lipoprotein and accumulation of cholesterol esters in peripheral nerves and other tissues. The aim of this study was to evaluate whether nerve high-resolution ultrasonography (HRUS) can detect morphological nerve changes in TD. Methods: Three related patients of a previously reported Italian family with Tangier disease, carrying the Y1698X mutation in ABCA1, underwent clinical, neurophysiological, and quantitative nerve HRUS evaluation. Nerve HRUS data were compared with normal controls. Results: Despite neurophysiological abnormalities, no quantitative HRUS abnormality was detected in peripheral nerves. Discussion: Normalcy of HRUS in neurophysiologically abnormal nerves suggests possible subtle abnormalities that escape quantitative HRUS detection. Systematic studies in larger TD cohorts with different mutations are needed to confirm our findings. Muscle Nerve 59:587–587, 2019     

Median nerve ultrasound in diabetic peripheral neuropathy with and without carpal tunnel syndrome

Introduction: Median nerve ultrasound shows increased cross‐sectional area (CSA) in carpal tunnel syndrome (CTS) and diabetic peripheral neuropathy (PN). The role of ultrasound in diagnosing CTS superimposed on diabetic PN is unknown. The objective of this study is to evaluate ultrasound for diagnosis of CTS in diabetic PN. Methods: Prospective recruitment of diabetics with electrodiagnostically proven PN, subdivided into cases (with CTS) or controls (without CTS). The gold standard for CTS was clinical diagnosis. NCS were correlated with blinded median nerve CSA ultrasound measurements. Results: Eight cases (CTS) and eight controls (no CTS) were recruited. Nerve conduction studies (NCS): Median nerve distal latencies (antidromic sensory; palmar; lumbrical motor; and lumbrical motor to ulnar interosseous difference) were significantly prolonged in CTS cases. No ultrasound measurement (distal median CSA, wrist‐forearm ratio, wrist‐forearm difference) reached significance to detect CTS. Area under the curve was greatest for lumbrical distal latency by receiver operator characteristic analysis (0.85). Conclusions: In this pilot study, NCS may be superior to ultrasound for identification of superimposed CTS in diabetic PN patients, but larger numbers are needed for confirmation. Muscle Nerve 47: 437–439, 2013     

Delayed facial weakness in Guillain‐Barré and miller fisher syndromes

Introduction: Dr. C. Miller Fisher described the appearance of unilateral facial palsy after resolution of ataxia in a patient with the eponymic Miller Fisher syndrome (MFS). However, there have been very few reports of delayed appearance of facial weakness in Guillain‐Barré syndrome (GBS) and MFS when the other neurological signs reached nadir or started improving. Methods: In this study we reviewed the clinical and laboratory findings of consecutive patients with GBS (n = 195) and MFS (n = 68). Results: Delayed facial weakness occurred in 12 (6%) GBS and 4 (6%) MFS patients and was unilateral in 5 (42%) GBS and 2 (50%) MFS patients. In those patients with delayed facial weakness, neither limb weakness nor ataxia progressed, and facial weakness disappeared without immunotherapy. Conclusions: Because facial weakness can lead to further morbidity, it would be prudent for clinicians to warn patients of this possibility, although additional immunotherapy is usually not required. Muscle Nerve 51 : 811–814, 2015     

Axonal neuropathy in female carriers of the fragile X premutation with fragile x–associated tremor ataxia syndrome

Introduction: In this study we examined whether females with the fragile X–associated tremor ataxia syndrome (FXTAS) and non‐FXTAS premutation carriers have electrophysiological signs of underlying peripheral neuropathy. Methods: Nerve conduction studies (NCS) were performed on 19 women with FXTAS, 20 non‐FXTAS carriers, and 26 age‐matched controls. The results were compared with existing data on corresponding male carriers. Results: Women with FXTAS and non‐FXTAS carriers had reduced sensory nerve action potential amplitudes. Also, there was a strong trend for reduced compound muscle action potential amplitudes in women with FXTAS, but not in non‐FXTAS carriers. No significant slowing of nerve conduction velocities, prolongation of F‐wave latencies, or associations with molecular measures was observed. Conclusions: This study suggests an underlying axonal neuropathy in women with FXTAS. However, in comparison to men with FXTAS, the NCS abnormalities in women were less severe, possibly due to the effect of a normal X chromosome. Muscle Nerve 52 : 234–239, 2015     

Ultrasound findings of carpal tunnel syndrome in a hunter syndrome patient

Introduction: Hunter syndrome (mucopolysaccharidosis II) is a rare genetic disorder. Carpal tunnel syndrome (CTS) is a common finding in these patients. Methods: We report the ultrasound findings in a 40‐year‐old Hunter syndrome patient with severe CTS. Results: Marked abnormalities of the median nerve were present proximal to the carpal tunnel with an unusual area of increased echogenicity between enlarged fascicles separating the area of maximal enlargement and the normal median nerve proximally. Conclusions: This case demonstrated unique ultrasound findings in a Hunter syndrome with CTS. Ultrasound also localized the median nerve lesion in the setting of end‐stage median neuropathy and nonlocalizing electrophysiology. Muscle Nerve 53 : 147–150, 2016     

Miller-Fisher综合征临床特点及亚型诊断(附27例报告)

目的分析Miller-Fisher综合征(MFS)的临床特点,并对其进行亚型诊断,以加深对其认识,提高诊治水平。方法回顾性分析27例诊断为MFS患者的发病诱因、临床表现、实验室检查、治疗及预后等临床资料,并依据2014年GBS分类专家组制定的Guillain-Barré综合征(GBS)和MFS的新分类和诊断标准进行亚型诊断。所有患者接受脑脊液、肌电图及血清抗GQ-1b抗体检测。结果27例患者平均患病年龄为(41.0±22.6)岁,14例患者有前驱感染史,主要临床表现为复视、步态不稳,主要体征为眼外肌麻痹、共济失调、腱反射减弱或消失等。18例患者出现蛋白细胞分离现象;17例患者血清抗GQ-1b抗体阳性;26例患者出现不同程度的神经根及周围神经受损表现。亚型诊断:典型MFS患者19例,MFS与GBS重叠型(MFS/GBS)5例,急性眼睑下垂(AP)1例,急性瞳孔散大(AM)1例,急性共济失调性神经病(AAN)1例。除1例患者仅接受营养神经等治疗外,余26例患者分别接受了免疫球蛋白和(或)激素冲击治疗,所有患者出院时症状好转。结论 MFS的诊断需要结合患者临床表现、脑脊液检查、神经电生理检查和血清抗GQ-1b抗体等,患者予以免疫球蛋白和(或)激素冲击治疗预后良好。     

Visual impairment in anti-GQ1b positive Miller Fisher syndrome

Autoimmune neuropathies such as the Guillain-Barré syndrome (GBS), the Miller Fisher syndrome (MFS), and chronic inflammatory demyelinating neuropathy (CIDP) have conventionally been considered diseases exclusively of the peripheral nervous system. In the last decades, however, several reports of CNS involvement in peripheral neuropathy have challenged this view. We describe a patient with anti-GQ1b positive MFS who--apart from the classical features--also presented with reversible loss of visual acuity suggesting CNS involvement.     

A standardized ultrasound approach in neuralgic amyotrophy

Neuralgic amyotrophy (NA), also referred to as idiopathic brachial plexitis and Parsonage-Turner syndrome, is a peripheral nerve disorder characterized by acute severe shoulder pain followed by progressive upper limb weakness and muscle atrophy. While NA is incompletely understood and often difficult to diagnose, early recognition may prevent unnecessary tests and interventions and, in some situations, allow for prompt treatment, which can potentially minimize adverse long-term sequalae. High-resolution ultrasound (HRUS) has become a valuable tool in the diagnosis and evaluation of NA. Pathologic HRUS findings can be grouped into four categories: nerve swelling, swelling with incomplete constriction, swelling with complete constriction, and fascicular entwinement, which may represent a continuum of pathologic processes. Certain ultrasound findings may help predict the likelihood of spontaneous recovery with conservative management versus the need for surgical intervention. We recommend relying heavily on history and physical examination to determine which nerves are clinically affected and should therefore be assessed by HRUS. The nerves most frequently affected by NA are the suprascapular, long thoracic, median and anterior interosseous nerve (AIN) branch, radial and posterior interosseous nerve (PIN) branch, axillary, spinal accessory, and musculocutaneous. When distal upper limb nerves are affected (AIN, PIN, superficial radial nerve), the lesion is almost always located in their respective fascicles within the parent nerve, proximal to its branching point. The purpose of this review is to describe a reproducible, standardized, ultrasonographic approach for evaluating suspected NA, and to share reliable techniques and clinical considerations when imaging commonly affected nerves.     

Dejerine-Sottas neuropathy with multiple nerve roots enlargement and hypomyelination associated with a missense mutation of the transmembrane domain of MPZ/P0

In a patient affected with a slowly progressive, severe form of Dejerine-Sottas syndrome, symmetric enlargement of cranial nerves and focal hypertrophy of cervical and caudal roots were detected following MRI. Neuropathological features of the sural nerve disclosed a dramatic loss of myelinated fibres, with skewed-to-the-left, unimodal distribution of the few residual fibres, consistent with the diagnosis of congenital hypomyelination neuropathy. Genetic analysis revealed this condition to be associated with a heterozygous G to A transition at codon 167 in the exon 4 of the MPZ/P0 gene causing a Gly138Arg substitution in the transmembrane domain of the mature MPZ/P0 protein. Focal enlargement of the nerve trunks in demyelinating, hereditary motor and sensory neuropathies (HMSN) was previously reported in both asymptomatic and symptomatic cases with root compression, but peculiar to this case is the diffuse involvement of both cranial and spinal nerves. We believe that the relevance of nerve trunk hypertrophy in HMSN is probably underevaluated: therefore MRI investigation of the head and spine should be included in the diagnostic study of selected HMSN patients. Molecular analysis of peripheral myelin genes will help to rule out misdiagnosed cases. Received: 9 January 2002, Received in revised form: 14 March 2002, Accepted: 19 March 2002