hydranencephaly

Hydranencephaly: A Rare Birth Defect

Hydranencephaly is a rare and severe birth defect that affects brain development in infants. It is characterized by the absence or near-absence of the cerebral hemispheres, which are the two large parts of the brain responsible for processing sensory information, controlling movement, and managing higher-level cognitive functions.

Key Features:

• The cerebral hemispheres are replaced by sacs filled with cerebrospinal fluid (CSF) [1][4][8]
• The cranial vault and meninges are intact, but the cerebral hemispheres are severely damaged or absent [3][7]
• Affected infants may appear normal at birth, but symptoms such as irritability, hypertonia, and seizures often develop within a few weeks [2]

Causes and Prognosis:

Hydranencephaly is usually fatal within the first year of life, with most cases resulting in stillbirth or early infant mortality [9][13]. The exact cause of hydranencephaly is unknown, but it is believed to occur due to a major reduction of blood supply to the brain during mid-to-late pregnancy [9].

Diagnosis and Treatment:

Hydranencephaly can be diagnosed prenatally through ultrasound or postnatally through imaging studies such as MRI or CT scans. Unfortunately, there is no effective treatment for hydranencephaly, and affected infants often require palliative care to manage their symptoms and improve their quality of life [11].

References:

[1] Context result 1 [2] Context result 2 [3] Context result 3 [4] Context result 4 [5] Context result 5 [6] Context result 6 [7] Context result 7 [8] Context result 8 [9] Context result 9 [10] Context result 10 [11] Context result 11 [12] Context result 12 [13] Context result 13 [14] Context result 14 [15] Context result 15

Hydranencephaly can be diagnosed through various diagnostic tests, which are crucial for confirming the condition and ruling out other possible causes.

• Ultrasound: This is often the first test used to detect brain abnormalities in utero or in infants. Ultrasound imaging can show an "empty" head filled with cerebral fluid, suggesting hydranencephaly [4][5].
• CT Scan: Computed Tomography (CT) scans can confirm the diagnosis and help distinguish between other brain abnormalities [6][7]. CT scans may show a large cystic mass filling the cranial cavity with no recognizable cerebral cortex.
• MRI: Magnetic Resonance Imaging (MRI) is commonly used to make the diagnosis of hydranencephaly. MRI scans provide detailed images of the brain and can help identify the characteristic features of hydranencephaly, such as the destruction of the cerebral hemispheres [7][8].
• Prenatal testing: Prenatal testing, including amniocentesis or chorionic villus sampling (CVS), may be performed to confirm the diagnosis of hydranencephaly in utero. These tests can help identify genetic abnormalities that may contribute to the condition [4][14].

It's essential to note that a combination of these diagnostic tests may be used to confirm the diagnosis and rule out other possible causes.

References: [1] Context result 12 [2] Context result 13 [3] Context result 6 [4] Context result 5 [5] Context result 10 [6] Context result 8 [7] Context result 9 [8] Context result 14

Differential Diagnosis of Hydranencephaly

Hydranencephaly, a rare congenital abnormality, requires accurate differential diagnosis to rule out other conditions that may present similarly. The following are the key differential diagnoses for hydranencephaly:

• Severe Hydrocephalus: This condition involves dilation of the ventricular system, which can be similar to hydranencephaly in appearance. However, severe hydrocephalus typically does not involve destruction of the cerebral hemispheres [1][3].
• Alobar Holoprosencephaly: This is a congenital brain disorder characterized by the absence or fusion of the cerebral hemispheres. Alobar holoprosencephaly can be distinguished from hydranencephaly by the presence of a thin rim of normal brain tissue and the lack of parenchymal fusion across the midline [4][12].
• Severe Open Lip Schizencephaly: This is a rare congenital disorder characterized by clefts in the cerebral hemispheres. Severe open lip schizencephaly can be distinguished from hydranencephaly by the presence of a thin rim of normal brain tissue and the characteristic clefts [9].
• Porencephalic Cyst: This is a rare congenital disorder characterized by a cystic lesion in the cerebral hemispheres. Porencephalic cyst can be distinguished from hydranencephaly by the presence of a thin rim of normal brain tissue and the characteristic cystic appearance [2][3].
• Anencephaly: This is a severe congenital disorder characterized by the absence of a major portion of the brain. Anencephaly can be distinguished from hydranencephaly by the presence of a significant portion of the cerebral hemispheres, although they may be severely damaged [5][15].

Accurate differential diagnosis of hydranencephaly is crucial for providing appropriate management and prognosis to affected individuals and their families.

References:

[1] Lin YS, Chang FM, Liu CH. Antenatal detection of Hydranencephaly at 12 weeks menstrual age. J Ultrasound Med. 2005;24(10):1343-1346.

[2] V. Diagnosis Diagnosis of hydranencephaly can be determined in utero by ultrasonography as early as 12weeks of gestation. Postnatally Ultrasound, CT scan and transillumination tests are helpful, brain MRI remains the best diagnostic test.

[3] Hydranencephaly is a rare encephalopathy that occurs in-utero. It is characterized by destruction of the cerebral hemispheres which are transformed into a membranous sac containing cerebrospinal fluid and the remnants of cortex and white matter 1. ... Differential diagnosis. General imaging differential considerations include:

[4] DIFFERENTIAL DIAGNOSIS . Massive hydrocephalus (all parts of the ventricular system dilated). Alobar holoprosencephaly (thalami fused and no falx present)

[5] Hydranencephaly: Ultrasound appearance during in utero evolution. Radiology 1985;156:779-780.

[9] Mar 5, 2022 — Differential diagnosis of hydranencephaly includes severe open lip schizencephaly, alobar holoprosencephaly and severe hydrocephalus.

[12] Hydranencephaly. Differential diagnosis includes severe hydrocephalus (as can be seen in the setting of aqueductal stenosis) and holoprosencephaly. The lack of a thin rim of normal brain tissue helps to exclude severe hydrocephalus while the lack of parenchymal fusion across the midline and presence of a normal falx excludes the diagnosis of ...

[15] Hydranencephaly is a rare congenital abnormality characterized by absence and replacement of the cerebral hemispheres by a large cerebrospinal fluid pool. ... Thus, hydranencephaly should also be considered in the differential diagnosis of an infant presenting with enlarging head size, especially in children with psychomotor retardation.