Mitochondrial disease and stroke.
OBJECTIVE
It is well known that some mitochondrial disorders are responsible for ischemic cerebral infarction in young patients. Our purpose was to determine, in this prospective ongoing study, whether ischemic stroke is the only manifestation of a mitochondrial disorder in young patients.


METHODS
Patients aged </=50 years, admitted to the Stroke Unit from January 1999 to May 2000 with a diagnosis of ischemic stroke of unknown origin, were included in the study. All of them had full biochemical and hematologic tests, neuroimaging studies, transesophageal echocardiography, and extracranial and transcranial Doppler sonography. Patent foramen ovale was ruled out. Lactic acid concentrations were measured after anaerobic exercise of the forearm, and a morphological, biochemical, and molecular study after biceps muscle biopsy was performed.


RESULTS
Of the 18 patients so far included, 3 (17%) presented lactic acid hyperproduction after physical exercise, and 6 (33%) showed deficit of the mitochondrial respiratory chain complexes. The molecular analyses have confirmed mitochondrial mutations at base pairs 3243 (characteristic of mitochondrial encephalomyopathy, lactic acidosis, and strokelike episodes [MELAS]), 4216, and 15 928.


CONCLUSIONS
These results suggest that ischemic stroke may be the only manifestation or the initial manifestation of a mitochondrial disorder.
Martínez-Fernández
E
E
Stroke and Neuromuscular Units, Department of Neurology, Hospital Universitario Virgen del Rocío, Sevilla, Spain. med010426@nacom.es
Gil-Peralta
A
A
García-Lozano
R
R
Chinchón
I
I
Aguilera
I
I
Fernández-López
O
O
Arenas
J
J
Campos
Y
Y
Bautista
J
J
D000293:Adolescent; D000328:Adult; D002545:Brain Ischemia / Q000175:diagnosis / Q000209:etiology; D004272:DNA, Mitochondrial / Q000032:analysis; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000032:analysis; D008297:Male; D028361:Mitochondrial Diseases / Q000150:complications / Q000175:diagnosis*; D009154:Mutation; D011446:Prospective Studies; D020521:Stroke / Q000175:diagnosis* / Q000209:etiology
D004272:DNA, Mitochondrial; D019344:Lactic Acid