Nerve Excitability Changes in Chronic Inflammatory Demyelinating Polyneuropathy: A New Clinical Diagnostic Biomarker (original) (raw)
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Membrane properties in chronic inflammatory demyelinating polyneuropathy
Brain, 2001
Threshold tracking was used to compare excitability properties (stimulus-response curves, strength-duration properties, recovery cycle and threshold electrotonus) of the median nerve in 11 patients with chronic inflammatory demyelinating polyneuropathy (CIDP) and 25 healthy controls. Stimulus-response curves were significantly different: threshold was much higher, the slope of the curves reduced and the spread of the thresholds greater in the CIDP group. The strength-duration time constant (τ SD ) was significantly shorter and the rheobase higher in the CIDP group. In the recovery cycle, the CIDP group had less refractoriness, supernormality and late sub-
Early identification of 'acute-onset' chronic inflammatory demyelinating polyneuropathy
Brain : a journal of neurology, 2014
Distinguishing patients with acute-onset chronic inflammatory demyelinating polyneuropathy from acute inflammatory demyelinating polyneuropathy prior to relapse is often challenging at the onset of their clinical presentation. In the present study, nerve excitability tests were used in conjunction with the clinical phenotype and disease staging, to differentiate between patients with acute-onset chronic inflammatory demyelinating polyneuropathy and patients with acute inflammatory demyelinating polyneuropathy at an early stage, with the aim to better guide treatment. Clinical assessment, staging and nerve excitability tests were undertaken on patients initially fulfilling the diagnostic criteria of acute inflammatory demyelinating polyneuropathy soon after symptom onset and their initial presentation. Patients were subsequently followed up for minimum of 12 months to determine if their clinical presentations were more consistent with acute-onset chronic inflammatory demyelinating po...
Journal of Neurology, Neurosurgery & Psychiatry, 2002
Background: Chronic inflammatory demyelinating polyneuropathy (CIDP) is a heterogeneous disorder having a wide clinical range, and is characterised by multifocal demyelination that can involve the distal nerve terminals, intermediate nerve segments, and nerve roots. Objective: To investigate whether the distribution patterns of demyelination along the course of the nerve correlate with clinical profiles in patients with CIDP. Methods: Motor nerve conduction studies were carried out on 42 consecutive patients. According to the physiological criteria for demyelination, the presence of a demyelinative lesion was determined in the distal nerve segments (distal pattern) or intermediate nerve segments (intermediate pattern), or in both (diffuse pattern). The serum concentration of tumour necrosis factor (TNF)-α was measured by immunoassay.
Muscle & Nerve, 2003
The diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP) relies primarily on clinical and electrophysiologic examination, but the nerve biopsy findings may be supportive, especially in atypical cases. In order to define the usefulness of nerve biopsy in this disease, we retrospectively studied 44 consecutive patients whom we classified as having CIDP on pathological grounds. We found that 8 of these 44 patients had pathological findings indicative of CIDP but did not meet any of the usually accepted electrophysiological criteria for its diagnosis. Among these eight patients, five responded favorably to conventional therapy. All of these eight patients had an electrophysiological pattern of generalized axonopathy with additional subtle findings suggestive of demyelination that prompted us to perform a nerve biopsy. Our data suggest that a significant number of patients with unrecognized CIDP are erroneously classified as having chronic idiopathic axonal polyneuropathy. CIDP should be suspected if the electrophysiological examination displays subtle abnormalities suggestive of demyelination, even in the presence of a prominent axonal pattern. Nerve biopsy in these patients may reveal abnormalities suggestive of CIDP and guide therapeutic options.
Acta Neurologica Scandinavica, 2016
To characterize changes in motor nerve conduction studies (MNCS) and motor unit number index (MUNIX) following treatment with subcutaneous immunoglobulin and to assess whether these changes are related to muscle strength. Methods: Data from 23 patients participating in a randomized, controlled trial were analyzed. MNCS and MUNIX were performed before and after 12 weeks of treatment. Isokinetic strength (IMS) was measured in various muscles together with grip strength (GS). Results: Proximally evoked compound muscle action potential (CMAP) amplitudes and MUNIX tended to be better preserved in treated patients (P=.049 and .045). Changes in other parameters did not differ between groups. There was no correlation between changes in electrophysiological parameters and IMS. Changes in GS were related to median nerve motor conduction velocity, distal motor latency, CMAP amplitudes, and distally evoked CMAP duration (P=.013-.035). Conclusion: Proximally evoked CMAP amplitudes appear to be the best MNCS parameter to assess treatment outcome in chronic inflammatory demyelinating polyneuropathy.
Journal of the Neurological Sciences, 2009
To develop diagnostic criteria for chronic inflammatory demyelinating polyneuropathy (CIDP), a retrospective series of patients' records diagnosed by sexpert consensus as CIDP or other chronic polyneuropathies were analyzed. Classification and regression tree analysis was applied to 150 patients to derive a classification rule. According to the rule, diagnosis of CIDP required that a patient have a chronic non-genetic polyneuropathy, progressive for at least eight weeks, without a serum paraprotein and either 1) recordable compound muscle action potentials in ≥75% of motor nerves and either abnormal distal latency in N 50% of nerves or abnormal motor conduction velocity in N 50% of nerves or abnormal F wave latency in N 50% of nerves; or 2) symmetrical onset of motor symptoms, symmetrical weakness of four limbs, and proximal weakness in ≥1 limb. When validated in 117 patients, the rule had 83% sensitivity (95% confidence interval 69%-93%) and 97% specificity (95% confidence interval 89%-99%) and performed better than published criteria.
Supramaximal Stimulus Intensity as a Diagnostic Tool in Chronic Demyelinating Neuropathy
Neuroscience journal, 2016
Objective. The ability to correctly identify chronic demyelinating neuropathy can have important therapeutic and prognostic significance. The stimulus intensity value required to obtain a supramaximal compound muscle action potential amplitude is a commonly acquired data point that has not been formally assessed as a diagnostic tool in routine nerve conduction studies to identify chronic neuropathies. We postulated that this value was significantly elevated in chronic demyelinating neuropathy. Methods. We retrospectively reviewed electrophysiology laboratory records to compare the stimulus intensity values recorded during median and ulnar motor nerve conduction studies. The groups studied included normal controls (n = 42) and the following diagnostic categories: chronic inflammatory demyelinating neuropathy (CIDP) (n = 20), acquired inflammatory demyelinating neuropathy (AIDP) (n = 13), Charcot Marie Tooth (CMT) type 1 or 4C (n = 15), carpal tunnel syndrome (CTS) (n = 11), and amyot...
Atypical pure sensory forms of chronic inflammatory demyelinating polyneuropathies
2019
Background: There are still not enough data on clinical and laboratory peculiarities of atypical chronic inflammatory demyelinating polyneuropathy (CIDP), ranging from only sensitive symptoms without weakness to asymmetric motor deficit. Recent epidemiological data do not clearly elucidate the percentage of cases with atypical CIDP from total CIDP types. Nerves conduction study, the gold standard in diagnosing demyelinating polyneuropathies has low sensibility for atypical forms of CIDP. The purpose of this study was determining the criteria for clinical and laboratory diagnosis of atypical sensory CIDP. Material and methods: Two groups of study were identified: 30 patients with typical CIDP and 30 patients with atypical CIDP. All patients underwent nerves conduction studies, blood was drawn for biochemical tests, also electrophoresis and serum protein immunofixation were done. Fibular nerve biopsy was performed in 9 patients. Overall Neuropathy Limitation Scale (ONLS) questionnaire was used for the assessment of functional disability. Results: Nerves conduction studies in cases with sensory CIDP show normal motor conduction velocity in 10 cases, and diminished only in 4 cases. Total ONLS in patients with sensory CIDP is equal to 1.85 ± 0.21 points compared to total 4.17 ± 0.240 points in patients with typical CIDP (p <0.001). Conclusions: Nerves conduction study is not a gold standard for diagnosis atypical sensory CIDP. According to functional scores results, sensory CIDP is less disabling compared with typical CIDP.
Annals of Neurology, 2000
Voluntary activity produces activity-dependent hyperpolarization of the active motor axons. The present study investigated whether this hyperpolarization produces conduction block in chronic inflammatory demyelinating polyneuropathy (CIDP). Studies were performed in 10 healthy control subjects, 7 patients with CIDP, and 3 patients with multifocal motor neuropathy. The compound muscle action potential (CMAP) of the abductor pollicis brevis was recorded in response to supramaximal stimuli to the median nerve at the wrist, alternating with measurements of axonal excitability. After a maximal voluntary contraction for 60 seconds, the amplitude of the maximal CMAP was significantly reduced in symptomatic CIDP patients by 40%, but there were only slight changes in the CMAPs of healthy controls, asymptomatic CIDP patients, and multifocal motor neuropathy patients. In symptomatic CIDP patients, the activity-dependent conduction block paralleled the activity-dependent hyperpolarization and was presumably precipitated by it. In these patients, the safety margin for impulse conduction was estimated to be about 12%. Activity-dependent conduction block may be clinically important in chronic demyelinating diseases and can be demonstrated electrophysiologically if testing occurs across pathological sites.