Spontaneous Disappearance Of A Large Middle Fossa Arachnoid Cyst
Surgical Neurology 24(2): Aug 1985; 181-183
View Original Source →Abstract
A case of a large middle fossa arachnoid cyst that spontaneously disappeared is reported. The possible mechanisms involved in the natural cure of this lesion and the indications for surgical versus conservative treatment of middle fossa arachnoid cysts are discussed.
Case Details
Personal Characteristics
A boy, aged 14, WHO had been complaining of frontal headache for some weeks, suffered from a generalized epileptic seizure in june, 1980.
Clinical Characteristics
On admission, neurologic examination disclosed no signs of increased intracranial pressure and the patient was symptom free. An electroencephalogram showed only slight diffuse abnormalities and antiepileptic therapy with phenobarbital was begun. X-ray films of the skull revealed a localized thinning and bulging of the left temporal bone. In december, 1980 a computed tomography (CT) scan showed a huge fluid collection on the left, located in the middle cranial fossa. The oval-shaped lesion had sharp edges; there was no perifocal edema but significant contralateral ventricular shift was evident.
Remission Characteristics
A CT scan on july 2, 1981, 7 months after the first examination, revealed a cyst markedly decreased in size. Furthermore, there was no longer compression of the ventricular system. A subsequent CT scan on november 16, 1981, showed a further decrease in size of the cyst in june, 1982 it had almost completely disappeared and ipsilateral ventricular dilatation had become evident.
Treatment & Mechanisms
Proposed Remission Mechanisms
Not discussed
Clinical Treatment
Antiepileptic therapy with phenobarbital
Additional Notes
Considering that the lesion was large but the symptoms slight, it was decided, in agreement with his parents wishes, to wait until the school term ended before making any decision as to treatment. Then, a metrizamide cisternography would be performed, before carrying out any operation. The boy has continued antiepileptic therapy and has not experienced any other seizures. His neurologic examinations have remained normal. At a recent clinical examination 5 years after his initial symptoms, the boy was found in perfect health; CT scan was unaltered.