[A study and follow-up of ten cases of benign enlargement of the subarachnoid spaces].

AIM

To present 10 cases with 'benign enlargement of the subarachnoid spaces' and its clinical and image evolution.

PATIENTS AND METHODS

We study 10 patients, 7 boys and 3 girls, because of macrocephaly. It was made a clinic and image follow-up from the first year of age to their cure. In the series, there are two monozygotic twins.

RESULTS

The patients had normal head circumference centile at birth, and it was 90 or higher at the age of 5 to 12 months, to keep stabilized, without decreasing, during the time of the study despite disappearing enlargement of the subarachnoid spaces. CT and especially magnetic resonance studies, showed the largest subarachnoid spaces and lateral ventricles between 5 and 12 months of age, and then, a slowly decrease to disappear in a period that was variable among the patients. A moderate enlargement was still found after 5 years of age in some cases. The clinic and image follow-up showed a parallel evolution since birth to 5 years in the pair of homozygous twins. Both showed possible reflux of the cerebrospinal fluid from the subarachnoid spaces to the cerebral ventricles, appearing cyst of the septum pellucidum, possibly due to the increase of the intraventricular pressure. The cyst did not disappear and kept the same size despite disappearing the enlargement of the subdural spaces and the normalization of the ventricular size. Psychomotor evolution has been normal, although most of patients show discrete hypotonus and motor coordination problems, attention deficit and/or hyperactivity.

CONCLUSION

Benign enlargement of the subarachnoid spaces has a spontaneous solution, but it can carried out in some cases more slowly than it is though. The disease seems hereditary and the most probable etiology is the difficulty in absorption of the cerebrospinal fluid during the first year of life or still longer. The picture, however, always has a spontaneous solution.