[Congenital basal encephaloceles involving functionally important structures]

In rare cases, basal encephaloceles can include important brain structures (pituitary gland, chiasm, third ventricle walls, cerebral vessels).

We reviewed 43 articles (78 cases) devoted to basal encephaloceles involving functionally important structures. Analysis included transsphenoidal and sphenoethmoidal hernias.

Nasal breathing disorders were found in 76.9% of cases, decreased visual acuity - 53.8%, endocrine disorders - 44.9%, nasal CSF leakage - 14.1%, meningitis - 10.3%. Concomitant malformations occurred in 85.9%. Severe respiratory disorders (52.6%, p<0.05) and multiple concomitant malformations (71.7%, p<0.05) were more common among patients with sphenoethmoidal encephalocele. Among 78 patients, 73.1% underwent surgery while follow-up was preferable in 26.9% of cases. There was progression of endocrine disorders (9.5%), visual impairment (4.8%) and nasal breathing disorders (4.8%) in follow-up period. Surgical treatment also has many risks. Transcranial, transnasal, transoral and combined approaches are currently used. It was not possible to establish the most effective surgical approach due to heterogeneous clinical data. Postoperative complications occurred in 47.4% of cases (endocrine disorders - 33.3%, CSF leakage - 8.8%, visual impairment - 1.8%, infectious complications - 14%). Mortality rate was 3.5%.

Congenital basal encephalocele involving functionally important structures is an extremely rare developmental defect. Such patients often have concomitant anomalies. Comprehensive examination is necessary to estimate the structures included in hernial sac and concomitant diseases. Treatment strategy should be determined individually after thorough examination and comparison of all risks. Surgical treatment is associated with high risk of complications due to damage to the structures comprising encephalocele.