Tabla I. Resumen de las variables epidemiológicas y la clínica neuromuscular. |
|||
N.o total |
% |
||
Sexo (n = 107) |
Varón |
53 |
49,5 |
Mujer |
54 |
50,5 |
|
Subgrupo por edad de inicio (n = 104) |
Congénito |
6 |
5,7 |
Infantojuvenil |
20 |
18,9 |
|
Adulto |
70 |
66,4 |
|
Presintomáticos |
8 |
7,5 |
|
Síntomas de inicio/motivo de consulta (n = 107) |
Neuromusculares |
39 |
36,45 |
Cardiológicos |
2 |
1,87 |
|
Respiratorios |
1 |
0,93 |
|
HiperCKemia asintomática |
2 |
1,87 |
|
Cuadro neonatal grave |
6 |
5,61 |
|
Diagnóstico en familiar de primer grado |
25 |
23,36 |
|
Madres diagnosticadas tras el nacimiento de neonatos con distrofia miotónica de tipo 1 |
8 |
7,48 |
|
Indeterminados |
24 |
22,43 |
|
Debilidad muscular (n = 107) |
Debilidad muscular objetivable Patrón más frecuente: debilidad distal en las cuatro extremidades |
87 38/87 |
83,18 43,67 |
Sin debilidad |
54 |
16,82 |
|
Miotonía clínica (n = 107) |
Sí |
68 |
63,55 |
No |
24 |
22,43 |
|
Indeterminado |
15 |
14,02 |
|
Pérdida de deambulación autónoma (n = 105) |
Sí |
10 |
9,52 |
No |
93 |
88,57 |
|
Indeterminado |
2 |
1,91 |
Tabla II. Resumen de hallazgos cardiológicos en el seguimiento de los pacientes con distrofia miotónica de tipo 1 de nuestra serie. |
|
Pacientes con estudio cardiológico, n (%) |
102 (95,3) |
Media de seguimiento (años) |
4,6 |
Trastornos del ritmo cardíaco, n (%) Ritmo sinusal Ensanchamiento del QRS Prolongación del intervalo PR Flúter auricular |
84 (95) 33 (47,5) 19 (24,7) 1 (1,2) |
Función ventricular Media de la FEV izquierda basal Reducción de la FEV izquierda, n (%) Disfunción diastólica, n (%) |
60,6% (± 9,2) 5 (6) 9 (17,3) |
Dispositivo cardíaco (n = 16) Marcapasos, n (%) Desfibrilador automático implantable |
14 (13,7) 2 (2) |
FEV: fracción de eyección ventricular. |
Tabla III. Resumen de hallazgos neumológicos en el seguimiento de los pacientes con distrofia miotónica de tipo 1 de nuestra serie. |
|
Pacientes con estudio funcional respiratorio, n (%) |
54 (50,4%) |
Parámetros ventilatorios CVF media (% predicho) Disminución de la CVF en supino-sedestación (% predicho) PIM media (cmH2O) PEM media (cmH2O) |
73,8 (± 19,9) 11 (± 9) 42,5 (± 19,6) 57,2 (± 23,2) |
Intercambio gaseoso-pulsioximetría nocturna SpO2 media (%) CT90 (%) |
91% (± 5%) 27,4 (± 4,3) |
Intercambio gaseoso-gasometría diurna pCO2 media (mmHg) Hipercapnia diurna, n (%) |
43,5 (± 5,2) 15 (28%) |
Poligrafía nocturna IAH Pacientes diagnosticados de SAHS, n (%) |
28,1 (± 18,6) 12 (8,5%) |
CT90: proporción del tiempo total de sueño con SpO2 inferior al 90%; CVF: capacidad vital forzada; IAH: índice de apneas-hipopneas del sueño; pCO2: presión parcial de CO2; PEM: presión espiratoria máxima; PIM: presión inspiratoria máxima; SAHS: síndrome de apnea-hipopnea del sueño; SpO2: saturación de oxígeno. |
Myotonic dystrophy type 1: a series of 107 patients Introduction. Myotonic dystrophy type 1 is the most common muscular dystrophy in adults. It is a genetic disorder of autosomal dominant inheritance and one of its most striking features is its multi-systemic involvement with a wide clinical phenotype. Patients and methods. Data from 107 patients with a genetically confirmed diagnosis of the disease were retrospectively analysed from the database of a national reference division for neuromuscular diseases. Demographic and clinical data were collected over a 7-year period. Results. The most frequent age of symptom onset was adulthood (66.4%). 35% showed exclusive distal weakness and a majority (63.6%) had clinical myotonia. Only 10 patients lacked neuromuscular symptoms at diagnosis and up to 9.5% were restricted to a wheelchair. The implantation of a pacemaker or cardioverter-defibrillator was conducted in 16 patients but no sudden cardiac death was detected. A venous thromboembolic disease incidence rate of 5.6 cases per 1000 patient-year was identified. More than half of the patients (54%) in the series developed respiratory failure. 13 patients died during the follow-up period, with respiratory failure being the main cause of death. Conclusions. The follow-up and clinical management of patients with DM1 should be multidisciplinary. In our series, the main cause of morbidity and mortality was respiratory disorders, whereas the incidence of cardiac disorders was lower. In addition, there is a notable frequency of complications derived from falls, which can have serious consequences. Finally, a higher than expected incidence of thromboembolic events was identified, which deserves further study in other cohorts of patients. Key words. Cardiomyopathy. Complications. Mortality. Myotonia. Myotonic dystrophy type 1. Respiratory failure. Steinert disease. |