Re: CMT and Restless Leg Syndrome

[Guest guest]

Lung. 2007 Jan-Feb;185(1):1-7.

Disorders of pulmonary function, sleep, and the upper airway in

Charcot-Marie-Tooth disease.Aboussouan LS, RA, Shy ME.

Department of Pulmonary & Critical Care Medicine, Cleveland Clinic

Foundation, 26900 Cedar Road, Suite 325-S, Beachwood, OH 44122, USA.

Charcot-Marie Tooth disease (CMT) encompasses several inherited

peripheral motor-sensory neuropathies and is one of the most common

inherited neuromuscular diseases.

Charcot-Marie-Tooth disease can be associated with several disorders

that may be encountered by the pulmonary physician, including

restrictive pulmonary impairment, sleep apnea, restless legs, and

vocal cord dysfunction.

Restrictive pulmonary impairment has been described in association

with phrenic nerve dysfunction, diaphragm dysfunction, or thoracic

cage abnormalities. Central sleep apnea may be associated with

diaphragm dysfunction and hypercapnia, whereas obstructive sleep

apnea has been reported as possibly due to a pharyngeal neuropathy.

Restless legs and periodic limb movement during sleep are found in a

large proportion of patients with CMT2, a type of CMT associated

with prominent axonal atrophy. Vocal cord dysfunction, possibly due

to laryngeal nerve involvement, is found in association with several

CMT types and can often mimic asthma. There may be special

therapeutic considerations for the treatment of those conditions in

individuals with CMT. For instance, bi-level positive airway

pressure may be more appropriate than continuous positive airway

pressure (CPAP) for the treatment of sleep apnea in the individual

with concomitant restrictive pulmonary impairment.

The prominence of peripheral neuropathy as a cause of the restless

legs syndrome in CMT may justify treatment with neuropathic

medications as opposed to the more commonly recommended dopaminergic

agents.

The risk of progression to bilateral vocal cord dysfunction in CMT

and the risk of aspiration with laryngeal neuropathy may limit the

therapeutic options available for vocal cord paralysis.