Basilar impression associated with impacted cisterna magna, spastic paraparesis and distress of balance: case report

Abstract

-We re p o rt on a 48 years-old man with basilar impression without syringohydromyelia, in which the cisterna magna was impacted by the cerebellar tonsils. Six months after posterior fossa decompre s s i o n there was the disappearance of nuchal rigidity, vertigo, spastic paraparesis and improvement of balance. Nevertheless hyperreflexia and diminished pallesthesia of the lower limbs persisted.KEY WORDS: basilar impression, Chiari malformation, syringomyelia, posterior fossa decompression, tight cisterna magna.I m p ressão basilar associada com cisterna magna impactada, paraparesia espástica e distúrbios do equilíbrio: relato de caso RESUMO -O presente relato descreve um homem de 48 anos com impressão basilar, sem siringo-hidro m i e l i a , no qual a cisterna magna se achava impactada pelas tonsilas cere b e l a res. O quadro clínico era caracterizado, especialmente, por paraparesia espástica. Seis meses após a descompressão da fossa posterior houve re g ressão da rigidez de nuca, vertigem, paraparesia espástica inicialmente observadas e melhora do equilíbrio. A hiperreflexia e a hipopalestesia persistiram nos membros inferiores.PA L AV R A S -C H AVE: impressão basilar, malformação de Chiari, siringomielia, descompressão da fossa posterior, cisterna magna impactada.Hans Chiari 1 , 2 (1891, 1895) described four types of c e rebellar anomalies. Type I was characterized by d o w n w a rd displacement of the cerebellar tonsils and the medial portions of the inferior cerebellar lobes, which accompanied the medulla into the cervical spinal canal. The type II showed downward displacement of portions of the cerebellum (1891), and portions of the inferior vermis (1895), pons, medulla oblonga and, at least, a part of lengthened fourt h ventricle, which reached the disc C 4 -C 5, into the enlarged cervical spinal canal. In type III, the hydrocephalic cerebellum, pons and medulla were inside a cervical meningocele (hydroencephaloceles cerebellaris cervicalis), through a spina bifida of the first three cervical vertebrae. In type IV, there was hypoplasia of the cerebellum without herniation of cerebellar stru c t u res into the spinal canal. Iskandar et al. 3(1998) related five cases of siringohydromyelia (SM), in which the cisterna magna was filled by the cerebellar tonsils. In all five cases there was clinical improvement after decompression of the posterior fossa and a marked reduction in the size of syrinx. These authours admitted that this dramatic response to d e c o m p ression indicates that this entity has a Chiarilike pathophysiology. On the other hand, Kyoshima et al. 4 related four similar cases with impro v e m e n t in symptoms and a reduction in syrinx size in thre e patients, and a reduction in ventricle size in two. These authors named the impacted cisterna magna by the cerebellar tonsils "tight cisterna magna", and called the description according to Iskandar et al.3 , "Chiari "0" malformation".

Cefaleia em Malformações da Junção Craniovertebral. Análise de 65 casos operados

“…A suspeita do diagnóstico de IB deve ser aventada em pacientes com alterações no exame neurológico; em especial, relacionadas ao acometimento das estruturas anatômicas da fossa posterior, como alterações dos pares cranianos baixos (disfagia, disfonia, rouquidão), cefaleia, disestesias do sistema superficial e profundo, vertigens, síncopes e outras queixas. Na inspeção pode-se avaliar a possibilidade de IB em um paciente com brevis collis, braquicefalia, implantação baixa dos cabelos e hipertelorismo características prevalentes nestes pacientes, especialmente a primeira alteração no biotipo do indivíduo 4,7 .…”