Loss of catecholaminergic neurons in the medullary reticular formation in myotonic dystrophy.
OBJECTIVE
To clarify the possible relation between the extent of involvement of catecholaminergic neurons and the presence of alveolar hypoventilation in patients with myotonic dystrophy (MyD).


BACKGROUND
Respiratory insufficiency has been reported frequently in MyD patients. Recent data support the hypothesis that this respiratory failure results from a primary dysfunction of the CNS.


METHODS
The authors performed a quantitative immunoreactive study of tyrosine hydroxylase immunoreactive (TH+) neurons linked to hypoventilation in the dorsal central medullary nucleus (DCMN), the ventral central medullary nucleus (VCMN), and the subtrigeminal medullary nucleus (SMN)--where the autonomic respiratory center is thought to be located--in eight MyD patients and in 10 age-matched control subjects. Alveolar hypoventilation of the central type was present in three of the MyD patients but not in the remaining MyD patients or the control subjects.


RESULTS
The densities of TH+ neurons of the DCMN, the VCMN, and the SMN in MyD patients with hypoventilation were significantly lower than in those without hypoventilation (p < 0.02, p < 0.01, and p < 0.01, respectively) and control subjects (p < 0.01, p < 0.01, and p < 0.01, respectively).


CONCLUSIONS
These data suggest that the loss of TH+ neurons of the DCMN, the VCMN, and the SMN is associated with the presence of hypoventilation in MyD and may be an important feature of MyD.
Department of Neurology, Teikyo University School of Medicine, Ichihara Hospital, Chiba, Japan.
S
S
Ono
K
K
Takahashi
K
K
Jinnai
F
F
Kanda
Y
Y
Fukuoka
H
H
Kurisaki
S
S
Mitake
T
T
Inagaki
T
T
Yamano
N
N
Shimizu
K
K
Nagao
D000368:Aged; D002395:Catecholamines / Q000502:physiology*; D002452:Cell Count; D005260:Female; D006801:Humans; D008297:Male; D008526:Medulla Oblongata / Q000473:pathology; D008875:Middle Aged; D009223:Myotonic Dystrophy / Q000150:complications / Q000473:pathology*; D009474:Neurons / Q000166:cytology* / Q000201:enzymology; D012131:Respiratory Insufficiency / Q000209:etiology / Q000473:pathology; D012154:Reticular Formation / Q000473:pathology*; D014446:Tyrosine 3-Monooxygenase / Q000032:analysis
D002395:Catecholamines; D014446:Tyrosine 3-Monooxygenase