Differential diagnosis
The differential diagnosis includes:
Symbrachydactyly
Congenital amputations
Hypoplasias of hand, digit, thumb
Adams–Oliver syndrome
ADAM complexADAM Complex; CRS is sometimes mislabeled as ADAM complex. ADAM is an abbreviation for Amniotic Deformity, Adhesions Mutilations. CRS is the malformation due to a constriction ring around mostly a limb. ADAM-complex is the association of limb defects (caused by constriction rings) and certain craniofacial clefts"Adams–Oliver syndrome is often mislabeled as CRS and consists of cutis aplasia of the scalp in which a longitudinal defect can vary in size and can often be associated with full-thickness skullcap loss. The distal digital or toe hypoplasia-aplasia is often confused with CRS. Constriction rings with or without edema are not present. The digital or toe hypoplasia-aplasia usually contains diminutive nails or nail folds". Classification
The constriction ring syndrome is a complex collection of asymmetric congenital anomalies, in which no two cases are exactly alike. This is why a classification is difficult to make. The most widely used classification system was proposed by Patterson. This classification system is based on the severity of the syndrome and is useful because, the different types require different treatments. Other clinicians have amended this scheme by separating the depth of the ring into mild, moderate, severe, and amputation and by further defining the presence or absence of lymphedema or soft tissue loss distal to the ring.
There is a 25% chance that both parents will pass the gene to their child, resulting in hydranencephaly. Genetic hydranencephaly afflicts both males and females in equal numbers. Post-natal brain injury
Though hydranencephaly is typically a congenital disorder, it can occur as a postnatal diagnosis in the aftermath of meningitis, intracerebral infarction, ischemia, or a traumatic brain injury. Diagnosis
An accurate, confirmed diagnosis is generally impossible until after birth, though prenatal diagnosis using fetal ultrasonography (ultrasound) can identify characteristic physical abnormalities. After birth, diagnosis may be delayed for several months because the infants early behavior appears to be relatively normal. The most accurate diagnostic techniques are thorough clinical evaluation (considering physical findings and a detailed patient history); advanced imaging techniques, such as angiography, computerized tomography (CT scan), and magnetic resonance imaging (MRI); and (more rarely) transillumination. However, diagnostic literature fails to provide a clear distinction between severe obstructive hydrocephalus and hydranencephaly, leaving some children with an unsettled diagnosis.Preliminary diagnosis may be made in utero via standard ultrasound, and can be confirmed with a standard anatomy ultrasound. Hydranencephaly is sometimes misdiagnosed as bilaterally symmetric schizencephaly (a less destructive developmental process on the brain), severe hydrocephalus (cerebrospinal fluid excess within the skull), or alobar holoprosencephaly (a neurological developmental anomaly). Once destruction of the brain is complete, the cerebellum, midbrain, thalami, basal ganglia, choroid plexus, and portions of the occipital lobes typically remain preserved to varying degrees.