Congenital muscular disease. Muscle weakness is
generally mild and nonprogressive. Cardiac involvement has been described;
the cardiomyopathy can be congestive, hypertrophic, or restrictive. Muscle
hypotonia begins in infancy (“floppy baby”) and is usually affecting mainly
the proximal musculature leading to decreased muscle bulk. Ptosis and
oculomotor palsy are sometimes observed.
Rare; 80 cases have been described.
Most cases seem sporadic, but an autosomal
recessive inheritance pattern is sometimes found.
Accumulation of desmin in both skeletal muscle and
Muscular biopsy shows increased variation in fiber size
and a predominance of type 1 fibers. Multiple circumscribed small lesions
(cores) are seen within each involved fiber. Both type 1 and type 2 fibers
are affected. Histologically, the core of the muscles are areas characterized by loss
and/or disorganization of the myofibrillar structure and by absence or
severe reduction of mitochondria.
Muscular weakness is generally mild and
nonprogressive, but cardiac involvement has been described in some patients.
The cardiomyopathy can be congestive, hypertrophic, or restrictive,
sometimes requiring cardiac transplantation. Muscle weakness that begins in
infancy (“floppy baby”) is usually proximal, with hypotonia and decreased
muscle bulk. Ptosis and oculomotor palsy are sometimes observed. Motor
development is delayed, but intelligence is normal. Diaphragmatic
involvement can lead to hypoventilation during sleep.
As in any child presenting with a
muscular disorder, thorough cardiac evaluation (ECG, echocardiography) is
mandatory; respiratory involvement should be assessed both in the awake and
the sleeping state (polysomnography). For elective surgical procedure, it is recommended to obtain
an anesthesiology consultation.
By analogy with central core disease,
malignant hyperthermia-triggering agents should be avoided in these
patients. One case of unexplained fever and death has been described in a
30-month-old boy with this disease a few hours after cardiac catheterization
with meperidine, hydroxyzine, and intravenous ketamine.
Careful titration of nondepolarizing
muscle relaxants if needed; succinylcholine should be avoided for fear of
rhabdomyolysis and hyperkalemia or even malignant hyperthermia crisis.
Gordon CP, Litz S: Multicore myopathy in a patient with anhidrotic ectodermal
dysplasia. Can J Anesth
Koch BM, Bertolini TE, Eng GD, et al: Severe multicore disease associated
with reaction to anesthesia. Arch Neurol
Willemsen MAAP, van Oort AM, ter Laak HJ, et al: Multicore myopathy with
restrictive cardiomyopathy. Acta Paediatr