Head Injury : Introduction, Fractures of Brain, Management of Fractures

Introduction Of Head Injury

• Head injury consist of 3-4% of emergencies. The patient is suffered from two types of injury: Primary, Secondary. Primary brain injury occurs due to the collision of head during road accident. Because of the primary impact (cerebral oedema), it increases intracranial pressure in the brain. A secondary injury occurs within a day or couple of days after the trauma.

The brain is surrounded by scalp. Layers are -Skin, Layers of dense connective tissue, Epicranial (Aponeurosis), Loose areolar tissue, Pericranium. The emissary vein is the connecting vein that connects the Dural venous sinus (present inside the brain) to the superficial vein. The diploic vein is a group of intraosseous veins embedded in the cancellous bone of the skull. Compression of the bleeding hand for 4-5 minutes can stop the bleeding.  It can be used to treat a 1 cm hand laceration. A scalp laceration results in profuse bleeding: As the blood vessels in dense connective tissue do not retract on their own. Mattress sutures or interlocking sutures are preferred to compress the vessels, and the bleeding is stopped.

• The brain is first surrounded by: Dura mater, Arachnoid mater, Pia mater. The space that is above the arachnoid is epidural space. The space that is below the dura mater is subdural space. The space that is below the arachnoid mater is subarachnoid space.

Introduction Of Fracture

Fractures of the Brain

• Skull fractures may involve the vault or basilar part of the skull. Vault fractures can be linear or depressed fractures. If the hairline crack occurs at the vault, this is known as a linear fracture.

A broken cranial bone with the bone depressed inward towards the brain is referred to as a depressed skull fracture, imprint fracture, or signature fracture because it takes the shape of whatever object collided with the skull bone. It shows depressed and displaced fractures. On the left side, linear and non-displaced fracture.

Also Read: Congenital Anomalies of the Kidneys and Urinary Tract

Management of Fractures

• Closed linear fractures are managed conservatively. Painkillers and prophylactic antibiotics. If a depressed skull fracture or a sign of open fracture is seen. It is managed by exploration and elevation. This is done by elevating that bone with debridement.  Intracranial air- In the CT scan report, if intracranial air is found, it indicates dura mater has been breached. It indirectly indicates that it is an open fracture that can be managed by broad-spectrum antibiotics with or without exploration. In the base of the skull, anterior, middle, and posterior cranial fossa are present, which can also be damaged.

Anterior Cranial Fossa Fracture

• There are few signs and symptoms that can help recognize anterior cranial fossa fracture. Some of the important symptoms are- If the dura mater is slightly breached, then the CSF flows down and results in CSF rhinorrhoea. Anosmia because nerves might be damaged. Racoon eyes/ Panda eyes /Black eyes. Subconjunctival hematoma

CSF Rhinorrhoea

• Cerebrospinal fluid (CSF) rhinorrhoea is a condition where the fluid that surrounds the brain leaks into the nose and sinuses. The clear watery discharge may happen when you bend over or straining. Reservoir sign (TeaPot sign)- May be seen on rising in the morning when the patient bends his bend. When the patient lies down, the CSF goes inside and is collected in the sphenoid bone, and when the patient stands up, this CSF is pushed outside via the nose.

Differential Diagnosis:

• The patient may have nasal discharge due to any kind of allergy or vasomotor rhinitis. There are 2 signs: Handkerchief sign and Double target sign, or Halo sign.

1.Handkerchief sign

• Patient is asked to discharge the nasal secretion into the handkerchief, and nasal discharge stifles the handkerchief because of the mucus content. In CSF rhinorrhoea, the handkerchief does not become hard.

2.Double target sign, or Halo sign

• Patient is asked to discharge the nasal secretion into the filter paper. CSF should have some blood, only then the Halo sign will appear. In the centre of the filter paper show red spot. Peripheral lighter halo is found.

The confirmatory test for CSF rhinorrhoea is beta-2 transferrin protein test. Beta-2 transferrin is a protein found in the CSF and not in nasal discharge. Its presence is specific and sensitive.

Raccoon eyes, also known as panda eyes, the panda sign, or the periorbital hematoma. This is characterised by a purplish halo around the orbit due to the collection of blood in the subcutaneous tissues of the eyes.

Subconjunctival Hematoma

• There is no posterior border to the haemorrhage when the patient looks away from the side of the fracture.

Middle Cranial Fossa Fracture      

• Important signs and symptoms are:  Battles sign also known as mastoid ecchymosis, is an indication of fracture of middle cranial fossa of the skull.

CSF Otorrhea

• CSF otorrhea is defined as leakage of cerebrospinal fluid (CSF) from the ear. Occurs only if there is breach in the tympanic membrane.

• The term "hemotympanum," defines the presence of blood (violet bluish accumulation) in the middle ear's cavity. In this, the tympanic membrane is intact. Bulging of the tympanic membrane is seen on an otoscope. There can be injury to 7^th and 8^th cranial nerves. 

Also Read: Thyroid Gland - Anatomy, Embryology, Developmental abnormalities, Symptoms, Investigation

Posterior Cranial Fossa Fracture

• Vernet syndrome, also known as jugular foramen syndrome, is a clinical condition characterised by IX, X, and XI cranial nerve dysfunction.

Base of Skull Fracture

• CSF leak will generally resolve spontaneously but persistent leak can result in meningitis so repair may be required. Not every patient with a CSF leak requires surgery, but if the meningitis or the persistent CSF leak requires surgery, prophylaxis is given to every patient. Blind nasogastric tube replacement is contraindicated in the base of skull fracture patients because the nasogastric tube may reach the fracture site, in the brain parenchyma.

Glasgow Coma Scale

• The Glasgow Coma Scale (GCS) is used to determine the degree of impaired consciousness. The scale rates patients based on their verbal, motor, and eye-opening responses, which are the three dimensions of responsiveness. 

1. Eye response

• This relates to how awake and alert you are. Eye response has four scores: If the patient opens their eyes spontaneously, the score is 4. If the patient opens the eye on verbal command, the score is 3. If the patient can open the eye to a painful stimulus, the score is 2. If the patient is not able to open the eyes, the score is 1.

2. Verbal response

• This measures your ability to think, remember, pay attention for a sustained period, and be aware of your surroundings. If the patient is normally conversing with you, the score is 5. If the patient is confused while talking, the score is 4. If the patient talks out of context i.e., inappropriate verbal response, the score is 3. If the patient is creating sound but is not talking, the score is 2. If the patient is unable to speak, the score is 1. Patients who are intubated are unable to speak, and their verbal score cannot be assessed. Only the eye opening and motor scores are used to evaluate them. The suffix T is added to their score to denote intubation. 

3. Motor response

• How well your brain can control muscular action. If the patient obeys your command, the score is 6. If a painful stimulus is given to the patient and the patient brings the hand to himself, the score is 5. If a painful stimulus is given to the patient and the patient flexes or withdraws the hand, the score is 4. If the patient is in abnormal flexion, the response score will be 3. If the patient is in abnormal extension, the response score will be 2. No motor response score will be 1. According to the GCS scale, the head injury can be classified into minor, mild, moderate, and severe head injury.

Minor and Mild Head Injuries

Lucid interval

• The time between regaining consciousness after a short period of unconsciousness caused by a head injury. Deteriorates after the onset of neurologic signs and symptoms caused by that injury is known as a lucid interval (LI). It can be due to expanding hematoma. An early CT scan should be done: If the patient has a persistently reduced consciousness level. Focal deficit: A focal neurologic deficit is a problem with nerve, spinal cord, or brain function. A focal deficit can affect any of these functions: Changes in movement, such as paralysis, weakness of one limb, loss of muscle control, increased or decreased muscle tone, or uncontrollable movements (such as tremors).
• Think of abuse when: They are present in extreme ages: children & elders. Different stages of injuries are present. If the patient goes to the doctor after 3-4 days when the injury is not fresh: delayed presentation. Retinal haemorrhage, when the injury is very severe. Multiple skull fractures. Neurological injury without external signs of injury.     

Because acute blood appears white on the non-contrast CT scan.

National Institute for Health & Care excellence (NICE) guidelines for CT in Head Injury

Indications for a CT Scan Within 1 Hour:

• If the patient has a GCS of less than 13 at any point during the evaluation, an immediate CT scan is done within 1 hour. If the patient has a GCS of less than 15 at 2 hours during the evaluation, then a CT scan is done immediately. Suspected open, depressed, or basal skull fracture. More than one episode of vomiting. Focal neurological deficit. Post traumatic seizures.

Indications for a CT Scan Within 8 Hours

• When the patient is over 65 years of age. If the patient is on any type of blood thinner medication like warfarin or aspirin. If the patient has a dangerous mechanism of injury, like a fall from a height or a road traffic accident:  CT scan is done within 8 hours. Retrograde amnesia lasting > 30 minutes.

National Institute for Health & Care excellence discharge criteria in minor & mild head injury

• If the patient is fine and doctor is going to discharge him.  He should have GCS of 15/15 with no focal neurological deficits. If the CT scan is normal, the patient can be discharged. The patient is not under the influence of alcohol or drugs. Patient accompanied by a responsible adult.

Verbal and written head injury advice: seek medical attention if:

• Persistent/ worsening headache despite analgesia
• Persistent vomiting
• Drowsiness
• Visual disturbances
• Limb weakness or numbness

Also Read: RENAL STONES - Etiology, Investigation and Management

Minor & Mild Head Injury 

Concussion

• A concussion is a state where consciousness is altered. Loss of consciousness (LOC) is not a prerequisite. Key features are confusion and amnesia. The patient may have some kind of gait disturbance or incoordination. Patients may be lethargic, easily distractible, slow to interact or emotionally labile.

Second Impact Syndrome

• Second impact syndrome (SIS), also known as repetitive head injury syndrome. It is a condition where a person experiences a second head injury before fully recovering from the first. The patient is vulnerable to repeated impacts.  A second minor injury triggers malignant cerebral oedema refractory to treatment. If a patient is an athlete with the primary impact and have even slight symptoms: Patient should not return to play. Symptoms can deteriorate very drastically.

Post-concussive Syndrome

• It is loosely defined as a constellation of symptoms, persisting for a prolonged period after injury. Patient may have: post traumatic headache , dizziness, disorders of hearing & vision. Neurocognitive & neuropsychological disturbances, like: Insomnia, emotional lability, fatigue, depression, personality change

Moderate & Severe Traumatic Brain Injury

Primary Survey

• In the primary survey, the GCS score is mandatory. Sternal or Supraorbital rub or trapezius squeeze represents an appropriate painful stimulus. Blood glucose level: Hypoglycemia is dangerous and easily reversible. Pupil size/reactivity sluggish or absent. Normally, when the torch is put on, the pupil size constricts. But in these patients, there is sluggish contraction or dilation. Uncal herniation compresses the 3rd cranial nerve, compromising the parasympathetic supply. Unopposed sympathetic supply produces sluggish, enlarged pupils.

Secondary Survey

• Cervical fractures present 10% of the time in moderate and severe traumatic brain injuries (TBI). CT does not exclude ligamentous injury. Midbrain or brainstem gaze dysfunction paresis: If the patient is not able to look across beyond the midline. Disconjugate gaze: inability of eyes to work together or roving eye movements. The thoracic sensory level is more easily established by sensory examination on the back. Priapism is a strong predictor of spinal cord injury even in intubated patients.

Types of Injury

1. Cerebral contusion
2. Extradural haemorrhage
3. SubDural haemorrhage
4. Sub arachnoid haemorrhage
5. Diffuse axonal injury

1. Contusion

• A region of injured tissue or skin in which blood capillaries have been ruptured. If the brain parenchyma is crushed or bleeding occurs inside the brain parenchyma, this is known as a cerebral contusion. The mechanism of injury is Coup and countercoup.

• If the patient met with an accident while driving. The patient was driving at 100 km/hour that means the patient's brain parenchyma was also moving at the same speed because the brain floats in the CSF. As he stops, the brain parenchyma hits the frontal bone at a speed of 100 km/h. Because the brain parenchyma is floating in the CSF, it bounces back, and the injury occurs in the occipital region. Injury that occurs at the primary or frontal part is known as coup, and the 180 degrees opposite to that frontal part is countercoup. Most commonly, it affects the inferior frontal lobe and temporal lobe. 
• Investigation of choice- NCCT head

• Acute extravasated blood looks white. Brain edema appears black.

Treatment

• Generally conservative management is enough. Decompressive craniectomy is used to treat diffuse brain oedema or focal hematomas that are producing intracranial hypertension and are resistant to medication therapy.   It is reportedly useful for lowering ICP, reducing the likelihood of herniation, and preventing subsequent injury. In this, we take a part of the skull out.

Extradural Hematoma (EDH)

• In this, blood collects between the skull & Dura.

Pterion

• Pterion is an H-shape spot that is the junction of three bones, i.e., frontal, parietal, and temporal. The pterion is the weakest and thinnest part of the skull. This part is most likely to get fractured in a head injury. Most common site is the temporal bone. Just below this there is a middle meningeal artery. A lucid interval is present. The middle meningeal artery is present just below the pterion. If the pterion gets ruptured, the middle meningeal artery can also get ruptured. The blood will accumulate above the dura mater, resulting in an epidural hematoma. It does not cross the suture line. Dura mater runs across the cranial bone with a very tight junction.  When the dura mater reaches the suture line, it does not cross the suture line in an epidural hematoma because of the tight junction. 20-50% of patients with epidural hematoma have lucid intervals.

Presentation

• 1/3 of patients have: Contralateral hemiparesis, reduced conscious level. Ipsilateral pupillary dilatation. The side of the body weakened by hemiparesis could be ipsilateral (the same side as the brain injury) or contralateral (opposite the side of the brain injury). Altered general condition and low GCS.

Investigation of choice 

• NCCT shows biconvex, lenticular, lens shaped or hyperdense lesions.

Also Read: Prune Belly Syndrome (Eagle Belly Syndrome)

Surgical management of Extradural Hematoma

• Done in neurosurgical emergency. GCS of the patient is <12-13. It can be done by: Burr hole, craniotomy

Burr hole

• A burr hole procedure allows the surgeon to drill holes in a patient's skull to relieve pressure from fluid or blood buildup. It can be done by electrical drill or manual drill. Then, evacuate the blood? pressure on brain parenchyma reduced.

Prognosis of Epidural Hematoma (EDH)

• Prognosis for promptly evacuated extradural hematoma without associated primary brain injury is excellent.

Subdural Hematoma (SDH)

• A subdural hematoma (SDH) is an accumulation of blood between the dura mater and the arachnoid. In this case, the bridging vein is ruptured. It results in bleeding. It is caused by injury to the cortical surface veins and bridging veins. Depending on the presentation, SDH is classified into three types: Acute SDH: If the patient comes to the doctor within 3 days of injury.  Subacute acute SDH:  If the patient comes to the doctor a little bit late, within 4–21 days. Chronic SDH: Old patients may come to the doctor when the injury is more than 21 days old.

Features of SDH

• It is usually caused by significant trauma. Nearly always associated with a significant primary brain injury. Impaired conscious level , deteriorates when hematoma expands. Hematoma crosses the suture line.

IOC for Acute SDH

Investigation of choice for acute SDH is NCCT. Hyperdense convexo-concave opacity. Banana shaped/ Crescent shaped opacity. Investigation of choice for chronic SDH is MRI.

Chronic SDH

• It appears even after the trivial trauma. Risk factors: elderly patients on anticoagulation. Trivial trauma is a very slight trauma, like falling.

Cerebral atrophy is seen in an old patient. As a result, it creates more space in the brain parenchyma. So even with trivial trauma, there is an increased chance of rupture. With this if the patient is on anticoagulants? increase the chances of bridging vein shearing. The main cause is that blood disintegrates into the breakdown products (take 2-3 weeks), which are osmotically active and cause intracranial pressure to rise. That’s why patient presents late. Clinical features- post traumatic headache, seizure, confusion, contralateral hemiparesis, coma.  Clotting function should be corrected. Smaller bleeds in neurologically stable patients managed conservatively. Bleeding with midline shift or deterioration, requires urgent evacuation. Burr holes for management are useless, as there is already clot formation.

Management of Acute SDH

Craniotomy 

• If the chronic SDH is more than 1 cm or any symptomatic SDH, it should be surgically drained. A follow-up head CT scan should be done one month later.

SAH (SubArachnoid Haemorrhage)  

• In this blood is accumulating below the arachnoid mater. Presentation: Loss of consciousness/ altered general condition. Excruciating Severe headache: thunderclap headache (worst headache). Signs of meningeal irritation:  Neck stiffness and vomiting. A focal neurological deficit is uncommon. Spinal fluid examination in subarachnoid haemorrhage (SAH). Xanthochromia- It is the yellowish to orange appearance of the cerebrospinal fluid. 
• Investigation of choice for Subarachnoid haemorrhage (SAH). NCCT of the Head. The white part indicates subarachnoid haemorrhage. It appears like fingers are going inside the brain (Dawson’s finger). Management of SAH: Conservative management

Diffuse Axonal Injury

• Widespread axonal damage involving both hemispheres after severe head injury. Mechanism of action: Acceleration/Deceleration or Angular strain to the brain. There is a shearing force between the grey matter and the white matter, and at this junction, the axonal membrane gets damaged. MC site is Lobar white mater > corpus callosum > brain stem. Clinical features:  Loss of consciousness / poor GCS of the patient. Most common cause of post traumatic vegetative state. Intracranial tension can be normal/ increased. Investigation- Investigation of choice is MRI. CT is often normal. Rarely hemorrhagic foci in corpus callosum and dorsolateral rostral brainstem may be suggestive. Poor progmosis

Important Questions

Q. What is the function of the emissary vein?

Ans: The emissary vein is the connecting vein that connects the dural venous sinus (present inside the brain) to the superficial vein.

Q. Where are Mattress sutures or interlocking sutures preferred? 

Ans: Mattress sutures or interlocking sutures are preferred over there to compress the vessels, and the bleeding will be stopped.

Q. Define linear fracture?

Ans: If the hairline crack occurs at the vault, this is known as a linear fracture.

Q. Explain depressed bone fracture.

Ans: A broken cranial bone (or "crushed" section of the skull) with the bone depressed inward towards the brain is referred to as a depressed skull fracture, imprint fracture, or signature fracture because it takes the shape of whatever object collided with the skull bone.

Q. How is Closed linear fracture managed?

Ans: It is managed conservatively; sometimes painkillers and prophylactic antibiotics is given.

Q. How is a depressed skull fracture managed?

Ans:  Depressed skull fractures managed by exploration and elevation.

Q. Where can the handkerchief sign be seen?

Ans: In CSF, rhinorrhoea

Q. What is the confirmatory test for CSF rhinorrhoea?

Ans: Beta-2 transferrin protein test

Q. Define raccoon eyes.

Ans: Raccoon eyes, also known as panda eyes, the panda sign, or the periorbital hematoma, are characterised by a purplish halo around the orbit due to the collection of blood outside the eyes' blood vessels under the soft tissues of the eyes.

Q. Battle sign is the symptom of-

Ans: Middle Cranial Fossa Fracture

Q. Define the term “hemotympanum.”

Ans: The term "hemotympanum," defines the presence of blood in the middle ear's tympanic cavity.

Q. Define Vernet syndrome.

Ans: Vernet syndrome is a pathological condition caused by IX, X, and XI cranial nerve dysfunction.

Q. Glasgow coma scale is used for-

Ans:  The Glasgow Coma Scale (GCS) is used to determine the degree of impaired consciousness. The scale rates patients based on their verbal, motor, and eye-opening responses, which are the three dimensions of responsiveness. 

Q. What is the best predictor for neurological outcome?

Ans: Motor score

Q. Define Lucid interval.

Ans: The time between regaining consciousness after a short period of unconsciousness caused by a head injury and deteriorating after the onset of neurologic signs and symptoms caused by that injury is known as a lucid interval (LI).

Q. What are the Indications for a CT scan within 1 hour:

Ans: If the patient has a GCS of less than 13 at any point during the evaluation, an immediate CT scan is done within 1 hour. If the patient has a GCS of less than 15 at 2 hours during the evaluation, then a CT scan is done immediately.

Q. Define dysfunctional gaze paresis.

Ans: It is the inability of the eye to look across the midline.

Q. Priapism is a strong indicator of-

Ans: spinal cord injury

If you are preparing for NEET-SS 2024 and ahead, check out SS ELITE Plan (Version 3.0) and what makes it the perfect study resource for your super speciality preparation.