Chronic Inflammatory Demyelinating Polyneuropathy and Respiratory Failure Due to Phrenic Nerve Involvement

Abstract

In this article, 2 patients with chronic inflammatory demyelinating polyneuropathy (CIDP) are presented. These patients developed respiratory failure which could not be explained by any cardiac or pulmonary pathology. The first case had pure motor involvement and probable CIDP, and the second case had severe sensorial dysfunction and an ataxic picture in addition to motor symptoms. His clinical picture was compatible with distal acquired demyelinating sensory neuropathy without M protein. Electrophysiologic investigations of both patients disclosed impaired phrenic nerve conduction and neurogenic motor unit changes in the diaphragm. Both patients showed a moderate response to immunotherapy. Distal acquired demyelinating sensory and pure motor variant of CIDP can be a cause of respiratory dysfunction. Different clinical patterns of CIDP should be evaluated for phrenic nerve involvement.

RETRACTED: Utility of phrenic nerve conduction studies for identification of patients with neuromuscular diseases requiring invasive mechanical ventilation

“…5 A study of 2 patients with chronic inflammatory demyelinating polyneuropathy (CIDP) and respiratory insufficiency reported slowed motor conduction velocities and reduced diaphragm CMAP amplitudes on PNCS. 6 Reduced CMAP amplitude has also been shown to be correlated with respiratory insufficiency in other muscular diseases, including muscular dystrophy and myotonic dystrophy (DM). 7 In this study we prospectively investigated whether PNCS parameters (amplitude and latency) could predict the need for IMV in patients with neuromuscular diseases by performing PNCS in patients with ALS, GBS, CIDP, or DM who were placed on IMV at our institution.…”

“…One study showed that PNCS results could independently predict respiratory insufficiency in patients with GBS because patients placed on IMV due to respiratory failure had lower CMAP amplitudes and longer latencies on PNCS, 4 and another study showed that reduced CMAP amplitude was correlated with the need for IMV 5 . A study of 2 patients with chronic inflammatory demyelinating polyneuropathy (CIDP) and respiratory insufficiency reported slowed motor conduction velocities and reduced diaphragm CMAP amplitudes on PNCS 6 . Reduced CMAP amplitude has also been shown to be correlated with respiratory insufficiency in other muscular diseases, including muscular dystrophy and myotonic dystrophy (DM) 7…”

Immunotherapy-responsive allodynia due to distal acquired demyelinating symmetric (DADS) neuropathy

“…This clinical presentation is more typical of small fiber neuropathy; however, the nerve conduction studies indicated distal demyelination of large myelinated nerve fibers as seen in DADS neuropathy. Allodynia with an otherwise normal neurological examination has not been reported in patients with DADS neuropathy or sensory CIDP . Larue and colleagues described a series of patients with anti‐MAG‐negative DADS neuropathy, 1 of whom presented with painful legs and allodynia without ataxia and had no associated monoclonal gammopathy, similar to our patients.…”

“…Sensory ataxia is the most common clinical presentation of DADS neuropathy, while disabling pain as the only and initial presentation of DADS neuropathy is uncommon and has been reported in only 1 patient . Our patients developed generalized disabling pain and extreme fatigue with a normal neurologic exam except for allodynia.…”

Incidence and Natural History of Idiopathic Chronic Inflammatory Demyelinating Polyneuropathy: A Population-Based Study in Iceland

“…Two of our patients (10%) had phrenic nerve palsy, which has increasingly been reported in CIDP [13,14] .…”