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Abstract

Syringomyelia associated with posterior fossa tumours is a very infrequent combination of pathological entities. The few cases which have been reported generally were asymptomatic in respect of the spinal cavitations. The authors report on a 36-year-old woman with a large extradural posterior fossa epidermoid tumour with a concomitant holocord symptomatic syringomyelia. Some of her symptoms were clearly attributed to the intraspinal cavitation. The lesions were both diagnosed by magnetic resonance imaging (MR). The patient did well after surgery of the brain lesion, with an objective improvement in her neurological status and a complete resolution of the syrinx documented by the MR 7 months after tumour removal. Syringomyelia in this case could be explained by blockage of the cerebrospinal fluid (CSF) circulation at the foramen magnum which in turn resulted in cranio-spinal pressure dissociation. This led to an accumulation of extracellular fluid (ECF) in the central canal, starting cavitation. Consequently, the syrinx was slowly expanded by the long-standing "slosh" effect of the systolic pressure waves. However, also via a distortion mechanism within the posterior fossa a pathologically plugged obex could have contributed to syrinx formation by means of preventing drainage of fluid from the ventricular CSF system.

Asymptomatic Syringomyelia in the Course of Medulloblastoma

“…Except for a few cases [4, 6, 11], the majority were asymptomatic with regard to the spinal cavitation [3, 5,7,8,9, 13]. This fact could be explained by an earlier diagnosis of syringomyelia, given the dominating clinical symptoms of the posterior fossa tumor [4].…”

“…Thus, there is an increased incidence of treatment-associated side effects, such as cognitive, hematological, otological, endocrinological, and neurological complications [22, 24, 25]. Syringomyelia related to medulloblastoma is rare (table 1 shows the reported cases), although there have been several reports of syringomyelia secondary to intracranial tumor [6,7,8], mainly of the posterior fossa [3,4,5, 9, 12]. …”

“…Most often, the syrinx develops at the cervical [3, 5, 7] or cervicothoracic level [4, 9, 13]; however, holocord syrinx has also been recorded [12]. …”

“…This fact could be explained by an earlier diagnosis of syringomyelia, given the dominating clinical symptoms of the posterior fossa tumor [4]. …”

“…Although syringomyelia associated with definite lesions and malformations at the foramen magnum has been widely documented [1, 2], syringomyelia related to intracranial tumor (mainly of the cerebral posterior fossa) is a rare condition [3,4,5,6,7,8,9]. Apart from syrinx due to spinal spread of medulloblastoma [10,11,12], to the best of our knowledge only 4 patients with syringomyelia linked to cerebellar medulloblastoma have been reported [13,14,15,16].…”