Penetrating Brain Injury – Causes, Symptoms, Treatment

Causes of Penetrating Brain Injury

Based on the speed of penetration, it can be classified into two categories:

• High-velocity penetration: Examples include injuries caused by bullets or shell fragments, from direct trauma or shockwave injury to surrounding brain tissue due to a stretch injury.
• Low-velocity penetration: Examples include a knife or other sharp objects, with direct trauma to brain tissue.[5]

Pathophysiology

The consequences of penetrating head injury depend on the following factors:

• Intracranial path and location: High mortality resulting from those that cross the midline, pass through the ventricles, or come to rest in the posterior fossa
• Energy and speed of entry: These factors depend on the properties of the weapon or missile. They result from energy being transferred from an object to the human skull and the underlying brain tissue. There is a high mortality rate associated with high-velocity projectiles. The kinetic energy involved is related to the square of the velocity. Three mechanisms of injuries have been reported.

1. Laceration and crushing
2. Cavitation
3. Shockwaves

• Size and type of the penetrating object: Usually, large missiles or missiles that fragment within the cranial vault cause more fatalities
• Circumstances or events surrounding the injury
• Other associated injuries

Primary injuries occur immediately. Secondary injuries occur following the time of the injury. The final neurologic outcome is influenced by the extent and degree of secondary brain injury. Therefore, the primary goal in the emergency department is to prevent or reduce conditions that can worsen outcomes, such as hypotension?, hypoxia, anemia?, and hyperpyrexia.

The amount of damage to the brain depends on the kinetic energy imparted to the brain tissue. This, in turn, depends on the following factors:

• Trajectories of both the missile and the bone fragments through the brain
• Changes in intracranial pressure at the time of impact.

Diagnosis? of Penetrating Brain Injury

The presentation depends on the mechanism, site of the lesions, and associated injuries.

History should include:

• Date and time of injury
• Duration of loss of consciousness (LOC) if present
• Seizure? at the time of impact
• Any co-morbidity (if existing)
• Anticoagulants and antiplatelet agents used

Initial physical examination includes primary and secondary trauma survey with the evaluation of other distracting injuries. A complete physical examination should be performed including a neurological examination. This should include documentation of the Glasgow coma scale (GCS). The involvement of cranial nerves should be assessed, and motor/sensory examination should be performed. It is important to realize that neurologic injury may be manifest distant to the site of impact. If unable to fully and formally assess cranial nerves secondary to lack of patient cooperation, it is important to, at least, document any findings relevant to the patient’s neurology.

Evaluation

In the pre-hospital setting, or in non-trauma facilities, stabilize, but, do not remove penetrating objects such as knives. Patients should be transported quickly to a location capable of providing definitive care. Early recognition of high-risk mechanisms, early imaging, and early evaluation at a level 1 trauma center may improve outcomes.[8][9]

In the emergency department, resuscitation and stabilization should be provided. Manage ABCDE’s using Advanced Trauma Life Support (ATLS) guidelines. Perform a primary survey to identify any life-threatening injury. Stabilize, focusing on the airway, breathing, and circulation, including external hemorrhage, while establishing and maintaining cervical? spine immobilization. Early activation of a trauma team may help to provide prompt recognition of polytrauma. The target is to maintain a systolic blood pressure of at least 90 mm Hg.

Following initial resuscitation and stabilization, an inspection of the superficial wound should be performed. Identify the entrance wound (and exit wounds, if present). Beware that blood-matted hair may cover these wounds. When a patient presents with a gunshot wound to the head, the other parts of the body including neck, chest, and abdomen should be inspected carefully for other gunshot wounds. Beware that injuries to the heart or great vessels in the chest or abdomen may be even more life-threatening.

A subgaleal hematoma can become extensive because blood easily dissects through the loose areolar tissue; such a hematoma can be a cause of hemodynamic compromise. Apply a sterile dressing to both the entrance and exit wounds. Assess whether there is any oozing of cerebrospinal fluid (CSF), blood, or brain parenchyma from the wound. Evaluate for hemotympanum, which may indicate a basilar skull fracture?. Examine all orifices for retention of foreign bodies, the missile, teeth, and bone fragments.

Perform neurological examination, including GCS and document well. Evaluating for signs suggesting raised intracranial pressure is critical. The initial signs and symptoms may be nonspecific and include a pain? in the head or upper neck. সহজ বাংলা: মাথাব্যথা।" data-rx-term="headache" data-rx-definition="Headache means pain in the head or upper neck. সহজ বাংলা: মাথাব্যথা।">headache?, nausea?, vomiting?, and papilledema.

Perform a careful examination of the neck, chest, abdomen, pelvis, and extremities. Assume multiple injuries in cases of penetrating trauma. Obtain a detailed history including the “AMPLE” history with an emphasis on events surrounding the injury. Also, determine the weapon type and/or caliber of the weapon.

CT Scan?

If the patient is hemodynamically stable, obtain a Computed Tomography (CT) scan of the head to evaluate for the presence of a mass ulcer?. সহজ বাংলা: শরীরের অস্বাভাবিক দাগ, ক্ষত বা ফোলা অংশ।" data-rx-term="lesion" data-rx-definition="A lesion is an abnormal area of tissue such as a spot, wound, patch, lump, or ulcer. সহজ বাংলা: শরীরের অস্বাভাবিক দাগ, ক্ষত বা ফোলা অংশ।">lesion? (hematoma) or cerebral edema?. It can be obtained when the patient is stabilized and ready to be transported to the radiology department. A CT scan? can adequately identify the extent of the intracranial injury and can also determine the relationship between the penetrating object and the intracranial structures. However, a radiolucent object, such as a wooden object, maybe missed by the CT scan. In patients with penetrating head trauma, a large mass or hematoma may be evident. If ICP is increased, aqueductal stenosis? is present, and the third but not fourth ventricle is enlarged.

Certain factors are important in critical decision making and have prognostic implications. These may include the following:

• Sites of entry and exit wounds
• Presence of intracranial fragments
• Missile track and its relationship to both blood vessels and air-containing skull-base structures
• Presence of intracranial air
• Trans-ventricular injury
• Basal ganglia and brain stem injury
• Whether the missile track cross the midline
• Presence of multi-lobar injury
• Presence of basal cistern effacement
• Brain parenchymal herniation
• Presence of any associated mass effects

Plain Radiograph

Maybe useful as it provides information about the following:

• Shape of the penetrating object
• Skull fractures (if present)
• An intracranial foreign object (if present)

Computed Tomographic Angiography (CTA)

• If a vascular injury is suspected, noninvasive investigative CTA should be obtained after patient stabilization.

Magnetic Resonance Imaging (MRI) Scan

• Additionally, an MRI Scan may be obtained if penetrating objects are suspected to be wooden objects. It should not be performed if intracranial metallic fragments are present. Such a procedure is contraindicated. However, if no bullets or intracranial metallic fragments are present, then an MRI scan of the brain can be performed in a stable patient. This can provide information about the posterior fossa structures and the extent of possible shared injuries.

Treatment of Penetrating Brain Injury

Patients with penetrating head trauma require both medical and surgical management.[rx][rx][rx]

Antibiotics – Intravenous co-amoxiclav 1.2g q8h OR intravenous cefuroxime 1.5g, then 750mg q8h AND intravenous metronidazole 500mg q8h for 7-14 days[rx][rx]

Anticonvulsants – Prophylactic phenytoin, carbamazepine, valproate, or phenobarbital is usually given in the first week after an injury[rx] Seizures may happen – The doctor may give you antiseizure medicines. Strong pain? relievers, like opioids, may be given through an IV.

Medical Management

A low threshold for obtaining surgical consultation should be considered in cases of penetrating head trauma. Beware that many patients with penetrating head trauma will likely require operative intervention.

Indeed, do not remove any penetrating object from the skull in the emergency department until trauma and neurosurgical evaluation is obtained. Also, the protruding object should be stabilized, and provision should be made to protect it from moving during transportation of the patient, to prevent further injury.

Assess the need for endotracheal intubation.

• Inability to maintain adequate ventilation
• Inability to protect the airway due to depressed level of consciousness
• Neck or pharyngeal injury

Normalize PCO2. Avoid hyperventilation, because it leads to vasoconstriction and a subsequent reduction in the cerebral perfusion pressure (CPP). This may worsen long-term neurological outcome. Beware that hyperventilation is only a temporizing measure for the reduction of elevated intracranial pressure (ICP). Avoid hyperventilation during the first 24 hours after injury when cerebral blood flow (CBF) often is reduced.

Monitor intracranial pressure (ICP) particularly in patients with GCS less than 8. Consider head elevation to 30 degrees. This can improve venous drainage and may decrease ICP. The target is to maintain intracranial pressure (ICP) less than 20 mmHg to 25 mmHg and CPP greater than 70 mmHg. Since cerebral blood flow (CBF) is difficult to measure continuously, the CPP is measured as a surrogate. Treatment typically is indicated for ICP greater than or equal to 20 mmHg to 25 mmHg, with guideline goals of ICP less than 20 mmHg and cerebral perfusion pressure (CPP) 50 mmHg to 70 mmHg.

Do no HARM for 72 hours after injury

• Heat—hot baths, electric heat, saunas, heat packs, etc has the opposite effect on the blood flow. Heat may cause more fluid accumulation in the fracture? joints by encouraging blood flow. Heat should be avoided when infection?, or irritation, often causing pain?, swelling?, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।" data-rx-term="inflammation" data-rx-definition="Inflammation is the body’s response to injury, infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।">inflammation? is developing in the acute? stage. However, after about 72 hours, no further inflammation is likely to develop and heat can be soothing.
• Alcohol stimulates the central nervous system that can increase bleeding and swelling? and decrease healing.
• Running, and walking may cause further damage, and causes healing delay.
• Massage also may increase bleeding and swelling?. However, after 72 hours of your fracture?, you can take a simple message, and applying heat may be soothing the pain?.

Medication

The following medications may be considered by your doctor to relieve acute? and immediate pain?, long term treatment

• Antibiotic – Cefuroxime or Azithromycin, or  Flucloxacillin or any other cephalosporin/quinolone, meropenem bacterial? infections. সহজ বাংলা: ব্যাকটেরিয়ার সংক্রমণের ওষুধ।" data-rx-term="antibiotic" data-rx-definition="An antibiotic is a medicine used to treat bacterial infections. সহজ বাংলা: ব্যাকটেরিয়ার সংক্রমণের ওষুধ।">antibiotic? must be used to prevent infection? or clotted blood removal to prevent further swelling, infection?, or irritation, often causing pain, swelling?, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।" data-rx-term="inflammation" data-rx-definition="Inflammation is the body’s response to injury, infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।">inflammation?, and edema.
• NSAIDs – Prescription-strength drugs that reduce both pain and inflammation. Pain medicines and anti-inflammatory drugs help to relieve pain and stiffness, allowing for increased mobility and exercise. There are many common over-the-counter medicines called non-steroidal anti-inflammatory drugs (NSAIDs). They include first choice NSAIDs is Ketorolac, then Etoricoxib, then Aceclofenac, naproxen.
• Muscle Relaxants –  These medications provide relief from spinal muscle spasms, spasticity.  Muscle relaxants, such as baclofen, tolperisone, eperisone, methocarbamol, carisoprodol, and cyclobenzaprine, may be prescribed to control postoperative muscle spasms, spasticity, stiffness, contracture.
• Calcium & vitamin D3 – To improve bone health, blood clotting, helping muscles to contract, regulating heart rhythms, nerve functions, and healing fractures. As a general rule, too absorbed more minerals for men and women age 50 and older should consume 1,200 milligrams of calcium a day, and 600 international units of vitamin D a day to heal back pain, fractures, osteoarthritis.
• Neuropathic Agents – Drugs(pregabalin & gabapentin) that address neuropathic—or nerve-related—pain. This includes burning, numbness, tingling sensation, and paresthesia.
• Glucosamine & Diacerein, Chondroitin sulfate – can be used to tighten the loose tendon, cartilage, ligament, and cartilage, ligament regenerates cartilage or inhabits the further degeneration of cartilage, ligament. The dosage of glucosamine is 15oo mg per day in divided dosage and chondroitin sulfate approximately 500mg per day in different dosages, and diacerein minimum of 50 mg per day may be taken if the patient suffers from osteoarthritis, rheumatoid arthritis, and any degenerative joint disease.[rx]
• Topical Medications and essential oil – These prescription-strength creams, gels, ointments, patches, and sprays help relieve pain and inflammation in acute trauma, pain, swelling, tenderness through the skin. If the fracture is closed and not open fracture then you can use this item.
•  Antidepressants – A drug that blocks pain messages from your brain and boosts the effects of endorphins in your body’s natural painkillers. It also helps in neuropathic pain, anxiety, tension, and proper sleep.
• Corticosteroids – Also known as oral steroids, these medications reduce inflammation. To heal the nerve inflammation and clotted blood in the joints.
• Dietary supplement – To eradicate the healing process from fracture your body needs a huge amount of vitamin C, and vitamin E. From your dietary supplement, you can get it, and also need to remove general weaknesses &  improved health.
• Cough Syrup – If your doctor finds any chest congestion or fracture-related injury in your chest, dyspnoea, post-surgical breathing problem, then advice you to take bronchodilator cough syrup.

What To Eat and What  to avoid

Eat Nutritiously During Your Recovery

All bones and tissues in the body need certain micronutrients in order to heal properly and in a timely manner. Eating a nutritious and balanced diet that includes lots of minerals and vitamins is proven to help heal broken bones and all types of fractures. Therefore, focus on eating lots of fresh food produce (fruits and veggies), whole grains, cereal, beans, lean meats, seafood, and fish to give your body the building blocks needed to properly repair your fracture. In addition, drink plenty of purified mineral water, milk, and other dairy-based beverages to augment what you eat.

• Broken bones or fractures bones need ample minerals (calcium, phosphorus, magnesium, boron, selenium, omega-3) and protein to become strong and healthy again.
• Excellent sources of minerals/protein include dairy products, tofu, beans, broccoli, nuts and seeds, sardines, sea fish, and salmon.
• Important vitamins that are needed for bone healing include vitamin C (needed to make collagen that your body essential element), vitamin D (crucial for mineral absorption, or machine for mineral absorber from your food), and vitamin K (binds calcium to bones and triggers more quickly collagen formation).
• Conversely, don’t consume food or drink that is known to impair bone/tissue healing, such as alcoholic beverages, sodas, fried fast food, most fast food items, and foods made with lots of refined sugars and preservatives.

Surgical Management

A major reason for surgical intervention is the presence of a hematoma. Large hematomas should be evacuated promptly. Early decompression with conservative debridement of the brain may be needed. In most cases, the removal of a deep-seated bullet may not be required. However, there are certain indications when removal should be considered. These are:

• Penetrating injury through pterion, orbit, or posterior fossa
• Presence of intracranial hematoma
• Presence of pseudoaneurysm at the time of initial exploration

A craniotomy is needed for low-velocity missile wounds in which the object is still protruding from the head. Some critical factors can determine the outcome for those who survive the initial injury; they depend on prompt and early surgical intervention as well as the ability to provide high-level neurocritical care.