HYDRANENCEPHALY

Hydroanencephaly

Hydranencephaly is a rare brain malformation in which the brain’s cerebral hemispheres do not develop, and are replaced by sacs filled with cerebrospinal fluid. Hydranencephaly is considered an extreme form of porencephaly (a disorder characterized by a cyst or cavity in the cerebral hemispheres), and may be caused by intrauterine strokes or infections, or maternal trauma. Hydranencephaly should not be confused with hydrocephalus, which is an increased accumulation of cerebrospinal fluid within the ventricles.

Diagnostic testing: The diagnosis is established by imaging such as MRI, CT, after ruling out conditions that are amenable to treatment. Preliminary diagnosis can be made in utero by ultrasound, but must be confirmed after birth.

Physical findings: Infants with hydrancephaly appear normal at birth, but within a few weeks, they may show:

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  Irritability;

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  Abnormal breathing patterns; and

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  Increased muscle tone.

Other features developing over time may include:

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  Seizures;

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  Abnormal head growth;

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  Deafness;

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  Blindness;

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  Spastic quadriparesis (paralysis); and

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  Cognitive deficits.

ICD-9: 742.3

Hydranencephaly develops after the 12^th week of pregnancy. The prognosis is generally poor, and many children die before the age of 1 year.

There is no definitive treatment for hydraencephaly. Treatment is symptom-specific and supportive.

SUGGESTED PROGRAMMATIC ASSESSMENT*

Suggested MER for Evaluation:

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  Clinical history and examination that describes the diagnostic features of the impairment;

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  Cranial MRI or CT scan; and

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  Developmental assessment.

Suggested Listings for Evaluation:

REMARKS