Critical illness neuromyopathy (CINM) is a common yet frequently overlooked complication in intensive care units (ICU). CINM often results in prolonged ventilator dependence and persistent limb weakness, significantly impacting patient recovery and long-term quality of life. CINM can be categorized into two primary subtypes: critical illness polyneuropathy (CIP) and critical illness myopathy (CIM). These conditions frequently arise in the context of severe sepsis, multiple organ failure, or as adverse effects of certain medications used in the ICU. This review aims to provide a concise overview of CINM, focusing on its pathophysiology, diagnostic approaches, and current clinical management strategies.
Nitrous oxide (N2O), an anesthetic gas, has been abused by some people for entertainment purposes. Recently, N2O (under the name of "Happy Balloon") abuse has become problematic among young people in Korea. N2O intoxication can develop a neuropathy, as well as other systemic disorders, either by inactivating vitamin B12 or by a direct neurotoxic mechanism. Here, we report a case of peripheral neuropathy with possible coexisting myelopathy following N2O abuse.
Primary hyperparathyroidism (PHP) is a disease in which excessive amounts of parathyroid hormone (PTH) are secreted and calcium levels in the blood increase. Hypercalcemia caused by PHP has a major influence on the peripheral nervous system and produces symptoms such as muscle cramps, paresthesia, and proximal muscle weakness. Here we report a rare case of sensory-dominant polyneuropathy caused by PHP, which improved after surgery.
Critical illness neuromyopathy (CINM) is a common but frequently underdiagnosed condition in critically ill patients that contributes to ventilator weaning failure and limb weakness in intensive care unit (ICU). CINM is subdivided into critical illness polyneuropathy and critical illness myopathy, and the occurrence of these conditions in the ICU is associated with multiple organ failure due to sepsis or certain medications. CINM survivors might have persistent functional disabilities and a poor quality of life. This situation demonstrates the need for efforts to minimize or prevent CINM in critically ill patients. This article provides a current overview of CINM and the associated clinical strategies.
Chronic inflammatory demyelinating polyneuropathy (CIDP) is an immune-mediated neuropathy with heterogeneous features. Appropriate treatment will produce a favorable outcome, but a poor treatment response and severe disability have also been reported. The roles of the clinical phenotypes and electrophysiological features of CIDP as well as of autoantibodies against nodal and paranodal proteins have been highlighted previously due to their association with the treatment response and long-term prognosis. This review addresses the diverse factors associated with the prognosis of CIDP.
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Tendon-Sparing Extraocular Muscle Enlargement Associated With Chronic Inflammatory Demyelinating Polyradiculoneuropathy Antonios D. Dimopoulos, Anne Barmettler Ophthalmic Plastic & Reconstructive Surgery.2024; 40(2): e38. CrossRef
Multifocal acquired demyelinating sensory and motor (MADSAM) neuropathy is a variant of chronic acquired demyelinating polyneuropathy. A 65-year-old women presented with upper arm weakness. A nerve conduction study showed conduction blocks over intermediate
segments with sparing of distal compound action potentials. Magnetic resonance imaging revealed asymmetric hypertrophy of the brachial plexus on the affected side. These findings
represent important electrophysiological and radiological evidence of MADSAM neuropathy. The condition of the patient began to improve after starting intravenous immunoglobulin administration.
The paraproteinemia is a disorder in which a single clone of plasma cells (monoclonal gammopathy) is responsible for the proliferation of monoclonal proteins (M-proteins). Approximately 10% of patients with idiopathic peripheral neuropathy have monoclonal gammopathy. Some M-proteins have the properties of an antibody to the components of peripheral nerve myelin, but the pathophysiological relationship between the neuropathy and the M-protein is often obscure. The relationship between peripheral neuropathy and monoclonal gammopathy requires the appropriate neurological and hematological investigations for precise diagnosis and treatment. In this review, we provide an update on the causal associations between peripheral neuropathy and monoclonal gammopathy as well as characteristics of clinical and electrophysiologic features.
Background: Early detection of neuropathy may prevent further progression of this complication in the diabetic patients. The purpose of this study was to evaluate the prevalence of early neuropathic complication in patients with newly diagnosed type 1 and type 2 diabetes. Methods: Nerve conduction studies (median, ulnar, posterior tibial, peroneal, and sural nerves) were performed for 49 type 1 (27 males, mean 14.1±7.5 years) and 40 type 2 (27 males, 42.0±14.1 years) diabetic patients at onset of diabetes. Children with age at onset under 4 years and adults over 55 years were excluded to eliminate the aging effect and the influence of obstructive arteriosclerosis. Neuropathy was defined as abnormal nerve conduction findings in two or more nerves including the sural nerve. Results: Mean HbA1c level was 12.6±3.3% for type 1 and 10.5±2.9% for type 2 diabetes. The prevalence of neuropathy was 12.2% for type 1, and 35.0% for type 2 diabetes, respectively. There were significant trends in the prevalence of neuropathy with increasing age (p<0.05). The effect of the mean level of glycosylated hemoglobin on the prevalence of polyneuropathy at onset of diabetes was borderline (p=0.0532). Neither sex of the patients nor the type of diabetes affected the neurophysiologic abnormalities at the diagnosis. Conclusions: Even in a population with diabetes at the diagnosis, the prevalence of subclinical neuropathy was not low. Neuropathy has been significantly associated with increasing age indicating the possibility of longer duration of undetected diabetes among them, especially in type 2 diabetes.
Thiamine deficiency can cause peripheral polyneuropathy and Wernicke’s encephalopathy. Wernicke’s encephalopathy is characterized by ataxia, ophthalmoplegia, nystagmus, and confusion, and typically presents acute and rapidly progressive course, whereas peripheral neuropathy associated with thiamine deficiency manifests chronic and slowly progressive one. However, acute and rapidly progressive axonal polyneuropathy combined with Wernicke’s encephalopathy is quite rare and unusual. Here, we describe a patient with Wernicke’s encephalopathy who presented with acute bilateral axonal neuropathy.
Multiple cranial and peripheral neuropathies as a delayed sequellae of ethylene glycol poisoning is a less well known clinical entity and its information about long-term electrophysiological and clinical outcomes is limited. We report a 45-year-old male who presented with acute renal failure and subsequently developed multiple cranial neuropathy, respiratory failure, and flaccid tetraparesis. Through sequential electrophysiological studies, we would like suggest that the main pathophysiology of ethylene glycol-related neuropathy is a demyelinating polyradiculoneuropathy with secondary axonal degeneration.
It was sometimes difficult to differentiate between acute-onset chronic inflammatory demyelinating polyneuropathy (A-CIDP) and subacute inflammatory demyelinating polyneuropathy (SIDP). The CNS involvement of these polyneuropathies has rarely reported in the literature. We present the case of a 42-year-old man who developed rapidly developing inflammatory demyelinating polyneuropathy followed by right optic neuritis. This case showed progressive motor weakness and sensory dysfunction with time to nadir at 8 weeks, demyelination in nerve conduction study, no other etiology of neuropathy, no relapse during follow-up of 18 months, good response to steroid and complete recovery which favor SIDP more than A-CIDP. We experienced the case of SIDP associated with optic neuritis.
Anorexia nervosa(AN) is a disorder characterized by disturbance of body image, fear of gaining weight, severe weight loss and, in female, amenorrhea. Compared with normal persons, patients with AN have neuropathic symptoms more frequently. But electrophysiologic abnormalities have rarely been reported. We experienced a case with recurrent neuropathic symptoms after severe weight loss. Further evaluation revealed AN. Electrophysiologic study showed sensorimotor polyneuropathy and focal neuropathy with conduction block. As far as we know, this feature of neuropathy in AN has not been described. We describe unusual feature of neuropathy in our patient with literature review.
The occurrence of muscle weakness in patients with sepsis or multiple organ failure managed in the intensive care unit has been recognized with increasing frequency in the last two decades. The difficulty in examining critically ill patients may explain why this complication has been only recently recognized. This weakness is due to an axonal polyneuropathy which is called critical illness polyneuropathy(CIP). It must be differentiated from myopathy or neuromuscular junction disturbance that can also occur in the intensive care setting. Neither the cause nor the exact mechanism of CIP has been elucidated. Electrophysiological studies demonstrated an acute axonal damage of the peripheral nerves. Before the recognition of CIP, these cases were usually misdiagnosed as Guillain-Barr?syndrome. Clinical recovery from the neuropathy is rapid and nearly complete in those patients who survive. Thus, neuropathy acquired during critical illness, although causing a delayed in weaning from ventilatory support and hosptial discharge, does not worsen long-term prognosis.
Objectives : Although the diagnosis of hereditary neuropathy with liability to pressure palsies(HNPP) in important for correct prognostic evaluation and genetic counseling, the diagnosis is frequently missed or delayed. Our main aim on undertaking this study was to characterized\ the electrodiagnostic features of HNPP. Material and Methods : Clinical, electrophysiologic and molecular studies were performed on Korean HNPP patients with 17P11.2 deletion. The results of eletrophysologic studies were compared with those of Charcot-Marie-Tooth disease type 1A (CMT1A) patients carrying 17p11.2 duplication. Results : Eight HNPP (50 motor, 39 sensory nerves) and six CMTIA (28 motor, 16 sensory nerves) patients were included. The slowing of sensory conduction in nearly all nerves and the distal accentuation of motor conduction abnormalities are the main features of background polyneuropathy in HNPP. In contrast to CMTIA, where severity of nerve conduction slowing was not different among nerve groups, HNPP sensory nerve conduction was more slowed in the median and ulnar nerves than in the sural nerve (p<0.01), and DML was more prolonged in the median nerve than in the other motor nerves (p<0.01). TLIs were significantly lower in HNPP than in the normal control and CMTIA patients for the median and ulnar nerves (p<0.01), and were also significantly reduced for the peroneal nerve (p<0.05) compared with those of the normal controls. Conclusion : The distribution and severity of the background electrophysiologic abnormalities are closely related to the topography of common entrapment or compression sites, which suggests the possible pathogenetic role of subclinical pressure injury at these sites in the development of the distinct background polyneuropathy in HNPP.
Background s and Objectives : In the length-dependent axonal polyneuropathy like diabetic polyneuropathy (DPN), the distal part of the longer axons are affected earlier. In cases of minimal distal axonal changes, nerve conduction studies (NCS) are frequently normal. If sural nerve is affected in the early stage of DPN, supportive parameters to detect the early axonal degeneration may be helpful. We investigated whether the sural/lunar SNAP amplitude ratio (SUAR) may be a more sensitive indicator than sural amplitude alone in the diagnosis of early diabetic polyneuropathy. Methods: We analyzed medical records and electrophysiological studies of 141 patients with DM and 30 healthy subject. The patients with early stage of DPN were defined as those having symptoms of neuropathy and normal NCS findings among the patients with DM. We compared SUAR between 57 patients with early stage of DPN and 71 age-matched control subjects. Results: Fifty seven patients had an average SUAR of 0.8, compared to that of 1,1 in the 71 normal controls. The SUAR of less than 0.9 was supplementary predictor of axonal polynerupathy, with the best balance of sensitivity and specificity (70%). The SUAR did not vary significantly with age, height or duration of DM. Conclusions: We conclude that the SUAR is a useful electrodiagnostic indicator to detect early stage of DPN.
Sarcoidosis is multisystemic granulomatous disease of unknown etiology ogenesis, and most frequently presented with bilateral hilar lymphadenopathy, pulmonary infiltration, skin and eye lesion. However, neurological involvement including peripheral neruopathy is relatively rare. We report a patient who had sensorimotor polyneuropathy without other systemic or organ involvements frequently reported in sarcoidosis. Laboratory investigation suggestive of sarcoidosis lead to sural nerve biopsy for confirmation, which demonstrated noncaseating granulomatous changes. Sarcoidosis should be included in the differential diagnosis in subacute polyneuropathy even if there is no usual symptoms or signs suggestive of the systemic disease.
B a c k g r o u n d: Somatosensory evoked potential (SSEP) is valuable for the evaluation of the central pathway.However, peripheral neuropathy sometimes renders the test useless by preventing the conduction from reaching theCNS. We postulated that the peripheral conduction problems could be overcome by proximal stimulation in SSEP andwanted to verify this in the study.Methods: Twenty patients with diabetic sensorimotor polyneuropathy were included. SSEP was elicited by stimulatingthe median and posterior tibial nerves. We compared the effect of distal and proximal stimulations in each SSEP inthe aspect of presence/absence and various latencies of resultant waves.Results: Among the 40 cases, proximal stimulation caused reappearance of subsided waves in 10 cases (25%). In themedian nerve SSEP, proximal stimulation made EN1 and CN2 visible which were not evident when distally stimulated.In the posterior tibial nerve SSEP, there was also improvement of forming waves when proximally stimulated.Conclusions: In the diabetic polyneuropathy, proximal stimulation of SSEP is more effective than the conventionaldistal stimulation in evaluating central pathway.
Background s and objectives: POEMS (polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes)syndrome is the rare cause of polyneuropathy. Although the polyneuropathy is essential for the diagnosis of the disease,the pattern of electrodiagnostic abnormalities has not been characterized in detail. The purpose of this study was to elucidatethe features of nerve conduction abnormalities in POEMS syndrome. Methods: We reviewed the medical recordsand nerve conduction studies (NCS) of 12 consecutive patients with POEMS. Results: A total of 68 motor and 46 sensorynerves were examined. Compound muscle action potentials (CMAPs) and sensory nerve action potentials wereabnormally attenuated or not elicited in majority of motor and sensory nerves (80.88% in motor, and 82.6% in sensorynerves). Frequency of the nerves with no potential was significantly higher in lower limbs than in upper limbs (p<0.01in both motor and sensory nerves), and CMAP amplitude was more reduced in lower limbs than in upper limbs(p<0.01). Conduction slowing was very frequently observed with 95% and 76% of motor and sensory nerves, respectively,having the abnormally reduced values of conduction velocity. Distal motor latencies were abnormally prolongedin 75% of motor nerves, and terminal latency indices were significantly higher in patients than in normal controls (p <0.05). Conduction block was observed only in 5% of motor nerves. Conclusions: NCS in POEMS syndrome showedcharacteristic patterns, in which conduction abnormalities were more frequently and severely affected in the lowerlimbs, and more predominantly in the intermediate nerve segments than in the distal portions. The recognition of thesecharacteristic patterns may be helpful in early diagnosis of polyneuropathy in POEMS syndrome.
Background and Objectives: The proximal and distal nerve segments are preferentially involved in acquireddemyelinating polyneuropathies (ADP). This study was undertaken in order to assess the usefulness of motor evokedpotential (MEP) and somatosensory evoked potential (SSEP) in the detection of the proximal nerve lesion in ADP.Methods: MEP, SSEP and conventional NCS were performed in 6 consecutive patients with ADP (3 AIDP, 3 CIDP).MEP was recorded from abductor pollicis brevis and abductor hallucis using magnetic stimulation of the cortex and thecervical/lumbar spinal roots. SSEP were elicited by stimulating the median and posterior tibial nerves. Latency fromcortex and cervical/lumbar roots, central motor conduction time (CMCT), EN1-CN2 interpeak latency were measuredfor comparison.Results: MEP was recorded in 24 limbs (12 upper and 12 lower limbs) and SSEP in 24 limbs (12 median nerve, 12posterior tibial nerve). F-wave latency was prolonged in 25 motor nerves (25/34, 73.5%). Prolonged CML and PMLwere found in 41.7% (10/24) and 45.8% (11/24), respectively. Interside difference (ISD) of CMCT was abnormallyincreased in the upper extremity, 66.7% (4/6 pairs) in case of CML-PML. EN1-CN2 interpeak latency was abnormallyprolonged in one median nerve (1/10) and LN1-P1 interpeak latency was normal in all posterior tibial nerves.Conclusions: MEP and SSEP may provide useful information for the proximal nerve and root lesion in ADP. MEPand SSEP is supplemental examination as well as complementary to conventional NCS.
The occurrence of polyneuropathy in association with monoclonal gammopathy of undetermined significance(MGUS) is quite common. However, reports of MGUS associated cranial neuropathies are rare. A 63 year-old womenwas presented with diplopia and swallowing difficulty. Neurological examination showed limitation of abduction ofright eye, right peripheral facial palsy, decreased hearing and gag reflex, left side deviation of uvula, and decreasedDTR. Sensorimotor polyneuropathy were observed with elctrophysiological studies. Protein and immunoelectrophoresisrevealed IgG
Background The most distal sensory fibers of the feet are often affected first in polyneuropathy. However, they are not evaluated in routine nerve conduction studies. Thus we evaluated the dorsal sural sensory nerve in patients with sensorimotor polyneuropathy with normal sural response, in order to assess the usefulness in electrodiagnostic practice.Methods: In this study, 53 healthy subjects and 27 patients with clinical evidence of sensorimotor polyneuropathy were included. In all subjects, peripheral motor and sensory nerve studies were performed on the upper and lower limbs including dorsal sural nerve conduction studies. On electrodiagnostic testing, all patients had normal sural responses.Results: The dorsal sural sensory nerve action potentials (SNAPs) mean amplitude was 13.12
Critical illness polyneuropathy (CIP) and critical illness myopathy (CIM) occur commonly in the patients who havebeen on mechanical ventilation for more than 1 week. Even in some patients diagnosed with CIP, an underlyingmyopathy may be the primary cause of the muscle weakness. The cormorbid status of CIP and CIM is called as criticalillness polyneuropathy and critical illness myopathy (CIPNM). We describe a 56-year-old man with acute quadriparesisand areflexia after systemic inflammatory response syndrome. The diagnosis of CIPNM is important to avoid unnecessaryinvestigations and unreasonably pessimistic prognosis. Electrophysiologic studies are essential for the diagnosis and forplanning further clinical management.
We report a 31-year-old man with cerebral adrenomyeloneuronopathy variant, who presented as progressive gait disturbance. He had spastic paraparesis, hyperreflexia without Babinski
Diabetic polyneuropathy (DPN) is the most frequently encountered form of neuropathy in diabetic patients, and it either relentlessly progresses or remains relatively stable for many years, not showing any trend towards improvement. From this point of view, early detection of DPN is very important to prevent the irreversible change of the peripheral nerve from diabetic insults. Although a number of clinical symptoms and/or deficit scales have been developed for clinical or research purposes, nerve conduction study (NCS) has been known one of the most objective and sensitive tools to detect peripheral nerve dysfunctions in diabetic patients. NCS, however, also have several shortcomings. The next two consecutive articles will focus on debates about diagnostic usefulness of NCS and on recent updates of other diagnostic tests including quantitative sensory testings and skin biopsy in the field of diabetic polyneuropathy.
Background Although quantitative sensory test (QST) is being used with increasing frequency for measuring sensorythresholds in clinical practice and epidemiologic studies, there has been no age-matched normative data in Korean adults.The objective of this study is to evaluate the value of QST in diabetic polyneuropathy with normal range in Korean adults.Methods: The Computer Aided Sensory Examination IV 4,2 (WR Medical Electronics Co., Stillwater, Minnesota, U.S.A.),with 4,2,1 stepping algorithm was used to determine vibration and cold perception threshold in 70 normal controls and 19patients with diabetic polyneuropathy aged from 21 to 79 years. The data were used to define age-matched upper and lowernormal limits and normal range of side to side difference. We also evaluated the duration of diabetes, serum HbA1C level,and findings of nerve conduction study (NCS) and QST in patients with diabetic polyneuropathy. Results: In normal adults,sensory thresholds slightly increased with age, and a slight side-to-side difference was observed. The diagnostic sensitivityof QST was not higher than NCS in patients with diabetic polyneuropathy (36.8% vs. 42.1%, p=0.716), especially amongelderly patients. Conclusions: QST might be used as a complementary test for NCS in the diagnosis of diabeticpolyneuropathy. Although the QST is a simple method for the evaluation of peripheral nerve function, there are somelimitations. Most of all, because the QST measuring is dependent on the subjective response of patients, the degree of concentrationand cooperation of the patients can significantly affect the result. And thus, attention should be paid during theinterpretation of QST results in patients with peripheral neuropathy.
Chronic inflammatory demyelinating polyneuropathy (CIDP) is an acquired immune-mediated polyneuropathy. Corticosteroids,intravenous immunoglobulin (IVIG) and plasmapheresis have been reported to be effective treatment. Rarely, CIDP can occurin the patients with HIV infection. The clinical features and electrophysiological findings of CIDP are known to be similarin patients with and without HIV infection. We report a 30-year-old male with HIV infection associated CIDP who improvedafter the administration of intravenous immunoglobulin and long term oral prednisone.
Subacute sensory neuronopathy and gastrointestinal pseudoobstruction are considered classical paraneoplastic neurologicalsyndromes. We report a 56-year-old male who presented with typical symptoms of subacute sensory neuronopathy andautonomic neuropathy with gastrointestinal pseudoobstruction. The biopsy of the palpable supraclavicular lymph noderevealed a small cell lung cancer. To our knowledge, intestinal pseudoobstruction and sensory neuronopathy in a small celllung cancer have not been reported in Korea.
Background Peripheral neuropathy is the most frequent neurological complication in human immunodeficiency virus (HIV)infection, related with diverse etiologies including inflammation, opportunistic infection and side effects of medications. Thepurpose of the present study was to evaluate characteristics of HIV associated neuropathy according to the stage of HIVinfection. Methods: In reviewing the medical records of HIV patients who underwent electrodiagnostic studies between 1997and 2011, total 11 patients (all males; median age, 47 years; range, 28-71 years) with comorbid neuropathy were enrolled. Stageof HIV infection was categorized according to the Centers for Disease Control and Prevention (CDC) criteria. Classificationof peripheral neuropathy was based on clinical and electrophysiological features. Results: Distal symmetric polyneuropathywas observed in 8 patients (72.7%), inflammatory demyelinating polyneuropathy in 2 patients (18.1%), and polyradiculopathyin 1 patient (9.1%). Median CD4+ T cell count was 123/mm3 (range, 8-540/mm3) and 7 patients (60%) had the mostadvanced HIV disease stage (CDC-C3). There was no neuropathy caused by CMV infection. Conclusions: Distal symmetricpolyneuropathy was the most common type of neuropathy in HIV infection, but various forms of neuropathy such asinflammatory demyelinating polyneuropathy and polyradiculopathy were also present. HIV associated neuropathy is morefrequently associated with advancing immunosuppression, although it can occur in all stages of HIV infection.
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