Acrania and Anencephaly

Difference Between Acrania and Anencephaly

Definition of Acrania and Anencephaly

Acrania and Anencephaly are congenital malformations that affect brain development in unborn fetuses leading to abnormalities of both their head and brain formation. Acrania (commonly referred to as exencephaly), occurs when cranial bones do not develop normally and result in no skull being present to protect the brain; additionally, amniotic fluid from within the uterus may expose more areas of the brain than would typically cover it.

Anencephaly occurs when both the skull and Brain do not develop correctly leaving a large section of the brain missing at birth. Babies born under these circumstances don’t receive their highest layer of skull development nor fully developed brains.


Acrania also referred to as Fetal Deprivation Syndrome, refers to a condition in which human fetuses lack any of the bones that form vault of cranial artery vault, with abnormal cerebral hemisphere development occurring without normal facial bone development, cervical column development, or skull absence as well as reduced brain volume during gestation. This causes birth defects known as Crania Syndrome.

Figure 01: Acrania

Congenital Acrania occurs most frequently during the 12th week of gestation (pregnancy). Genetic and chromosomal abnormalities play a large role in its occurrence; diagnosing Acrania typically requires ultrasound examination; risks increase if relatives have already had Acrania symptoms.


Anencephaly refers to insufficient development of the skull, brain, and scalp during embryonic development – typically during weeks 3-6 of gestation – due to an embryonic neural tube defect that prevents its closure properly – leading to insufficient brain development resulting in Anencephaly.

Anencephaly is an inherited disorder with genetic components. Although its causes remain elusive, many genes and environmental triggers play an active role in its manifestation; trisomy 18 may also play a part.

Figure 02: Anencephaly

Infants born with anencephaly have some distinct features.

Absence of the forebrain (front part of brain).

Inadequacy from both cerebral hemispheres as well as cerebellum

Involvement of exposed brain tissue due to no skull.

Assumptive Conditions such as limited mental capacities and high mortality rate could potentially exacerbate these health conditions further, leading to impaired consciousness and consequent high fatal rate.

Differences between Acrania and Anencephaly

Acrania and Anencephaly are rare congenital malformations which affect brain and skull development during gestation; they differ significantly in terms of characteristics that define them both as separate disorders with distinct manifestations.

Acrania and Anencephaly
Figure-No-03: Acrania and Anencephaly

Here are the major distinctions between Anencephaly and Acrania:

1. Brain Exposure: Acrania refers to an absence of skull; while anencephaly involves missing large portions of brain – most specifically the top portion – through birth or injury. Acrania exposes the cerebral cortex directly to amniotic fluid within the uterus due to no skull being present to protect it; anencephaly is when there is no upper portion of skull covering over part or all of it, yet remains protected by an outer layer of membranes and skin coverings.

2. Prognosis: Anencephaly and acrania have poor prognoses as neither condition fits with normal life, though infants born with anencephaly may live for some period after birth while those suffering from acrania usually do not make it beyond infancy.

3. Prevalence: Acrania is an extremely rare condition. Acrania occurs in Approximately one of every 10,000 pregnancies while anencephaly can affect one out of 1,000 Pregnancies.

4. Other Birth Defects: Babies with Anencephaly may also suffer From other birth defects In some instances babies born with Anencephaly could also develop other birth defects like spina bifida conversely those born with acrania tend to be less likely to suffer from other defects than babies who do not share this trait.

5. Diagnostic Procedure: Both Acrania and Anencephaly disorders are generally identified prior to birth using ultrasound scans or tests like Magnetic Resonance Imaging (MRI). Acrania typically features missing skull structure; while anencephaly exhibits insufficient brain development.

Two conditions affecting how the brain develops are brain and skull degenerative conditions, each having unique symptoms and effects on development.

Acrania and Anencephaly share several similarities

Acrania and Anencephaly a may appear to be two distinct disorders, each possessing unique symptoms; yet there may be similarities amongst both congenital malformations – for instance:

1. Cause: Both disorders appear to be connected by environmental and genetic influences such as maternal deficiency of folic acid or exposure to chemicals or toxins; infections during gestation; etc.

2. Diagnostic Timeline: The two conditions can typically be detected during gestation through ultrasound testing or Magnetic Resonance Imaging (MRI), typically during the second trimester pregnancy.

3. Poor Prognosis: Unfortunately, both conditions typically carry poor prognoses due to being incompatible. There may be rare occasions in which infants with anencephaly can survive briefly after birth; however babies born with acrania rarely make it beyond birth.

4. Family Effects: Both illnesses have an enormous effect on families’ mental and emotional well-being; parents can become distressed from grief, anxiety and depression following the loss of a child and require counseling or support in dealing with it afterwards.

Even with their similarities, anencephaly and acrania should be treated as separate conditions with distinct outcomes. Understanding their distinction will enable parents and Healthcare providers to make more informed decisions regarding diagnosis Treatment and care of these two conditions.


Acrania and Anencephaly are congenital disorders originating in neural canal. Their symptoms are detected using ultrasonography. Ultrasonography provides accurate detection, while major distinction between Acrania and Anencephaly relates to differences in brain tissue, in Acrania visible brain tissue may be visible while it would remain obscure in Anencephaly; therefore timely diagnosis is crucial, otherwise children with these conditions have little chance of survival.