Head Trauma in Cats
Dr. Debra Primovic
Veterinary care should include diagnostic tests and subsequent treatment recommendations. Complete medical history and physical examination, including neurological and ophthalmic (eye) examinations. Your veterinarian should assess for shock and trauma, thus monitoring airway, breathing, heart rate and presence of bleeding or fractures.
Diagnostic tests must be performed to confirm the diagnosis of head trauma and exclude other diseases that may cause similar symptoms. The initial diagnostic approach may include:
Assessment of hematocrit, which is the level of circulating red blood cells, to rule out bleeding (as with any trauma)
Serial neurological examinations to assess progression and prognosis and to gauge therapy
Radiographs (X-rays) of the skull to look for fractures when the cat is stable
Evaluation of arterial blood gas samples to detect low blood oxygen levels (hypoxemia) or evidence of breathing difficulty (hypoventilation)
Additional diagnostic tests may be carried out in order to detect other injuries:
Thoracocentesis (tapping of chest cavity) to drain abnormal air or blood in the chest cavity
Blood pressure measurements to evaluate for shock. It is important to maintain a systolic blood pressure of 80 to 100 mm Hg.
Radiographs of other limbs or the spine to assess associated injuries
Abdominal radiographs if indicated to assess injury
Thoracic (chest) radiographs
When a head trauma patient does not respond to symptomatic therapy or if a definitive diagnosis has not been attained, other diagnostic tests may be considered. Options may include:
Referral to a neurologist or internal medicine specialist
CT scan. This is available at some referral institutions (can detect hemorrhage, brain swelling, penetrating foreign bodies and depressed skull fractures).
MRI (magnetic resonance imaging), which is available at some referral institutions
Evaluation of brainstem auditory evoked potential to determine some brain stem functions
Intracranial pressure measurement, which may determine the severity of an increase in intracranial pressure and aid in assessment of response to therapy
Other tests may be indicated. These tests may reflect systemic effects of trauma or hypoxemia (low blood oxygen level) or pre-existing disease. There are no blood chemistry changes consistent with brain injury but these evaluations may also be useful in situations where alternate diagnoses are being considered.
Hemogram (a differential blood count)
Biochemistry profile, including blood glucose (sugar)
Blood ammonia level, because high levels may be seen in certain diseases of the liver
Coagulation studies if intracranial hemorrhage may be responsible for neurological signs
Electrocardiogram to aid in evaluation of abnormal heart rates
Treatment of head trauma must be individualized based on the severity of the condition and other factors that must be analyzed by your veterinarian. Initial therapy of head trauma follows rapid assessment of head injury and neurologic status. It includes oxygen therapy, possibly steroids (controversial), hyperosmotic fluids and repeat neurological examinations. Pain, seizures and hemorrhage are usually treated according to need. Severe cases of head trauma may be referred to an emergency clinic or neurologist.
Oxygen may help reverse the cerebral (brain) edema and prevent the progression of brain damage. Oxygen may be provided via face mask or hood or by the use of a nasal cannula or oxygen cage. If the patient is not breathing appropriately and has high blood carbon dioxide levels, it may be necessary to breathe for the patient following intubation – a tube is placed down the windpipe and breathing is maintained by use of a manual breathing bag or a mechanical ventilator. This may aid in reducing the degree of cerebral edema and preventing further brain injury.
Obvious hemorrhage should be controlled as with any trauma. Evaluation for traumatic damage to body cavities such as the chest and abdomen, such as abnormal bleeding or air accumulation (hemothorax and pneumothorax) or fractures of bones, should be carried out following initial stabilization of the patient.
Elevation of the head may help decrease intracranial pressure and facilitate resorption of spinal fluid. When moving the patient, it is important to prevent compression of the jugular veins, as this can raise intracranial pressure and cause a deterioration in neurologic status.
Intravenous fluids may be given initially to treat shock. Dextrose may be added if hypoglycemia (low blood sugar) exists. Fluids may also be used to maintain blood pressure which helps to maintain an adequate blood supply to the brain. Hyperosmotic agents such as mannitol are often used in patients with head trauma, particularly where there is a concern about cerebral edema, increased intracranial pressure, or a deteriorating neurologic status.
Diazepam (Valium®) or phenobarbitol may be needed to control seizures.
Conservative treatment may be used for non-displaced skull fractures. Surgery should be considered with depressed skull fractures or penetrating foreign bodies in the case of worsening neurological signs.
Cats may need to be sedated or tranquillized to prevent self-injury, particularly if agitated. Cages may be padded.
Frequent turning to prevent bedsores and lung congestion. Patient should be kept clean and dry.
Provide oral or intravenous nutrition as appropriate.
Monitoring is an important part of treatment. Your cat's temperature should be monitored and heat support may be provided as necessary. Fluid and electrolyte balance, blood pressure and urine output should be monitored and fluid and drug therapy adjusted accordingly. Serial neurological examinations are usually important to assess treatment and progression of symptoms.
Pain should be treated with analgesics such as butorphanol.
Eyes should be lubricated if the blink reflex is diminished.
The prognosis is dependent upon the degree and area of brain injury, response to therapy as well as secondary injuries. Coma that lasts greater than 48 hours or deteriorating clinical signs carry a grave prognosis for recovery.