RESUMO
Arnold-Chiari Malformation (ACM) was first described by Hans Chiari in 1890. Four types of this malformation are recognized, of those, type I is the most common among adults. It is caused by an elongation of the cerebellum into the conic projections that accompany the brain stem within the spinal channel. It is mostly congenital but "acquired" forms can be seen in the context of infections or posterior fossa tumors. Clinically, it can present as an asymptomatic finding, but it can produce brain stem compression. Syringomielia--cavitation of the brain stem central areas--is associated with MAC type I in 75 to 85% of cases. Clinical signs include pain, weakness, extremity parestesia. A shunt to the lateral ventricles can produce IV ventricle entrapment and is associated with cerebrospinal fluid blockage. We describe a case of MAC type I associated with the presence of syringomielia, syringobulbia and IV ventricle entrapment.
Assuntos
Anormalidades Múltiplas/diagnóstico , Malformação de Arnold-Chiari/complicações , Malformação de Arnold-Chiari/diagnóstico , Encefalopatias/complicações , Encefalopatias/diagnóstico , Tronco Encefálico , Ventrículos Cerebrais , Siringomielia/complicações , Siringomielia/diagnóstico , Adulto , Humanos , MasculinoRESUMO
La malformación de Arnold Chiari (MAC) fue descrita inicialmente por Hans Chiari en 1890. Existen cuatro tipos, de los cuales el tipo I es el más frecuente en adultos y se encuentra por la elongación de las amígdalas y las divisiones mediales del lóbulo inferior del cerebelo hacia las proyecciones cónicas que acompañan al bulbo raquídeo en el canal espinal. Su origen es congénito, aunque puede presentarse como una forma adquirida en el contexto de infecciones o tumores de fosa posterior. Clínicamente puede comportarse de manera asintomática o dar sintomatología de compresión de bulbo raquídeo. La siringomielia cavitación de las áreas centrales de la médula espinal se asocia a la MAC tipo I; en 75 a 85% de los casos se manifiesta con dolor, debilidad o parestesias de extremidades. El ventrículo IV atrapado se debe a un cortocircuito a los ventrículos laterales y se asocia a bloqueo de la circulación del líquido cefalorraquídeo. Se describe un caso de MAC tipo I asociado a siringomielia, siringobulbia y ventrículo IV atrapado.
Arnold-Chiari Malformation (ACM) was first described by Hans Chiari in 1890. Four types of this malformation are recognized, of those, type I is the most common among adults. It is caused by an elongation of the cerebellum into the conic projections that accompany the brain stem within the spinal channel. It is mostly congenital but [quot ]acquired[quot ] forms can be seen in the context of infections or posterior fossa tumors. Clinically, it can present as an asymptomatic finding, but it can produce brain stem compression. Syringomielia--cavitation of the brain stem central areas--is associated with MAC type I in 75 to 85% of cases. Clinical signs include pain, weakness, extremity parestesia. A shunt to the lateral ventricles can produce IV ventricle entrapment and is associated with cerebrospinal fluid blockage. We describe a case of MAC type I associated with the presence of syringomielia, syringobulbia and IV ventricle entrapment.