| Acalvaria is an uncommon inborn deformity in | | | | of the calvarium but an intact layer of skin over |
| which the thin bones of the cranial hurdle, | | | | the brain parenchyma. It results because of the |
| duramater and associated muscles are missing but | | | | primary non-closure of the neural tube or may be |
| the key anxious structure is normally untouched. | | | | a part of a spectrum of anencephaly. Acalvaria |
| The circumstance is often confused by prenatal | | | | has also been described with amniotic bands. The |
| ultrasonography with anencephaly or an | | | | disorder is etiologically and pathogenetically |
| encephalocele. Whereas the cerebral hemispheres | | | | heterogeneous and its prevention by ingestion of |
| are missing in anencephaly, the cranial contents in | | | | folic acid has not been described. |
| acalvaria are mostly comprehensive, though some | | | | Acalvaria has normally been described as a deadly |
| neuropathological irregularity is frequently existing. | | | | anomaly and reports are uncommon in the Indian |
| The presumed pathogenesis of acalvaria is | | | | literature. Amniotic band syndrome is an |
| defective migration of the membranous | | | | aetiological factor in acalvaria. The diagnosis of |
| neurocranium with natural arrangement of the | | | | acalvaria can be made by the 12th week of |
| immature ectoderm, resulting in absence of the | | | | gestation by high-resolution ultrasonography. The |
| calvaria but an undamaged bed of rind over the | | | | sono graphic differential diagnosis includes |
| mind parenchyma. | | | | anencephaly, cephalocele, osteogenesis imperfecta |
| Acalvaria may be associated with | | | | and hypophosphatasia. During pregnancy the alpha |
| holoprosencephaly, hydrocephalus and | | | | fetoprotein levels are reported to be very high, |
| micropolygyria. Cardiac anomalies, omphalocele, | | | | while the unconjugated estriol is undetectable. No |
| hypertelorism, cleft mouth and palate, renal | | | | surgical procedures to correct the skull defect |
| tubular dysgenesis, hexadactyly, club foot and | | | | have been reported in the newborn period and |
| congenital medulloblastoma have been reported. | | | | infancy. Spontaneous bone growth has been seen |
| Acalvaria is a postneurulation defect, that is, it | | | | in some newborns with scalp defects such as in |
| results due to faulty migration of the | | | | cutis aplasia. Conservative management with a |
| mesenchyme with normal placement of the | | | | careful follow-up and bone grafting at school age |
| embryonic ectoderm. There is, thus, an absence | | | | have been recommended. |