Hydrocephalus Jan 28, 2009 9:57:30 GMT -5
Post by charmingnancy on Jan 28, 2009 9:57:30 GMT -5
What is Hydrocephalus?
Hydrocephalus is a neurological disease in which there is excessive accumulation of cerebrospinal fluid (CSF) within the ventricular system of the brain.
CSF is normally formed in the brain. It bathes, protects, and circulates through parts of the brain and coverings and is then absorbed into the circulatory system. In young animals, CSF can accumulate in the brain causing the fontanel (the soft spot that normally closes after birth) to bulge. The bones of the skull are soft and can be enlarged due to the increased volume and pressure leading to a dome shaped cranium. The eye position within in the eye socket may be abnormally deviated where the sclera (white portion of the eye) is visible in both eyes towards the nose.
What causes Hydrocephalus?
Causes of hydrocephalus in young animals include congenital defects, intrauterine or perinatal infections, perinatal trauma, and central nervous system tumor. The most common cause of hydrocephalus in young animals is congenital defect.
Other causes are Canine distemper; Parvovirus; Parainfluenza virus; Bacterial meningitis; Aberrant parasitic migration; Fungal encephalitis; Ependymoma; Choroid plexus papilloma; Meningioma; Pharyngioma; and Epidermoid & dermoid cysts.
What breeds are affected by it?
Toy breeds have the highest incidence. Some commonly affected breeds include the Chihuahua, Maltese, Yorkshire terriers, English bulldogs, American bulldogs, Lhasa Apso, Pomeranian, and Toy poodles. Both males and females are equally affected.
What are signs that your dog may have it?
Symptoms of hydrocephalus vary with the cause, the age at presentation, the brain tissue being compromised, and the degree of tissue damage.
What to Watch For:
Altered mental status; Crying out; Hyperexcitability; Extreme dullness; Coma; Seizures; Visual or auditory impairment; Spastic or clumsy walking; Circling; Head pressing; Head tilt; or Abnormal eye movements.
How is it diagnosed?
Diagnostic tests are needed to identify hydrocephalus and differentiate it from other diseases that may cause similar signs.
In addition to obtaining a complete medical history and performing a thorough general physical examination, your veterinarian will likely perform or recommend the following tests: Neurological assessment; Laboratory work assessing kidney and liver function; Skull radiographs; Computed tomography or magnetic resonance imaging; Ultrasound of the brain if there is an open fontanel present; Spinal tap (rarely performed); or Electroencephalogram (EEG).
How is it treated?
The goal of treatment is to minimize or prevent brain damage by improving CSF flow. Treatment depends on the severity of the clinical signs and may include one or more of the following:
Medical treatment consisting of drugs that either decrease the production of CSF or increase CSF absorption; Surgical treatment of hydrocephalus that includes direct removal of the obstruction or shunting of CSF to an area outside of the brain; Prevention of trauma such as falling or rapid changes in pressure; Follow-up examinations throughout the animal's life to evaluate any progressive brain damage and to adjust treatments.
What is the prognosis?
Untreated severe hydrocephalus has a poor prognosis and usually results in death. Although the efficacy of therapy cannot be assessed without attempting treatment, the severity of clinical signs correlates with the success of treatment. Animals with symptoms that are difficult to manage are poor candidates for medical or surgical treatment.
Some animals with congenital hydrocephalus have an immediate response to medical or surgical treatment and can be stable over a long period of time.