Head and Spine Trauma
An epidural hematoma is a blood clot that develops between the skull and the dura (the lining between the skull and the brain). An epidural hematoma usually develops after trauma and is often associated with an overlying skull fracture. Epidural hematomas are less likely to be associated with severe, underlying brain injury than subdural hematomas. Epidural hematomas often develop when an adjacent fracture lacerates a meningeal artery. Arterial blood rapidly fills the space between the skull and the dura. The hematoma may cause significant pressure on the underlying brain. Epidural hematomas usually develop after trauma and may be seen in any age group. Diagnosis is by CT, and treatment is by surgical evacuation.
A subdural hematoma is a blood clot that develops between the dura (the lining between the skull and the brain) and the brain. A subdural hematoma usually occurs after traumatic brain injury and is usually associated with a severe head injury and significant neurologic deficit. These are classified as acute subdural hematomas, and they develop due to tearing of veins that bridge from the brain surface to the dura. The same forces that act to shear the bridging veins also may act to shear underlying nerves in the brain. Acute subdural hematomas may develop at any age. More benign forms of subdural hematoma may result as the brain atrophies with age. The bridging veins become significantly stretched and shear with a very minor force. These types of hematomas are known as chronic or subacute subdural hematomas. Often the blood in these hematomas has broken down and has liquefied. Such hematomas are usually seen in patients over 65 years of age. However, they may develop in younger patients who are on anticoagulant medications. Any patient with a subdural hematoma may present with a coma or with severe confusion. Subacute and chronic subdural hematomas may present by simple headache or mild confusion. Diagnosis of these lesions is by CT and treatment often involves surgical drainage.
Basilar skull fractures are a special subset of skull fractures. They occur as a result of trauma and affect the bottom of the skull near the ear canals or the nasal passages. Anterior basilar skull fractures involve the thin area of the skull where the olfactory (smelling) nerves exit into the nasal passages. Temporal basilar skull fractures involve the area of the skull where the vestibulocochlear (hearing and balance) and facial (facial muscles) nerves exit into the ear canal. Basilar skull fractures may involve dysfunction in the adjacent nerves with loss of smell, loss of hearing, imbalance, or weakness in the facial muscles. These skull fractures may tear the lining (dura) over the brain and result in a leakage of cerebrospinal fluid (CSF) into the ear (otorrhea) or nose (rhinorrhea). They may also permit blood to leak behind the ear (Battle's sign) or around the eyes (Raccoon eyes). These fractures are diagnosed clinically by the presence, after trauma, of otorrhea, rhinorrhea, Battle's sign, or Raccoon eyes. CT also aids in the diagnosis. These fractures heal with surgical intervention. In certain cases of leakage of CSF into the ear or nose, surgical intervention is required to repair the tear in the dura.
A concussion is a transient neurological deficit occurring after trauma. Concussions may occur in any age group and are usually associated with a transient loss of consciousness and transient amnesia (loss of memory) for the moments just prior to the trauma. The diagnosis of concussion is a clinical one, and there is no radiological imaging method that permits the diagnosis. Patients with a concussion usually make a full recovery. However, many patients have difficulty over several months. Patients may have difficulty adding, concentrating, and sleeping. They may also complain of headaches. This group of symptoms is known as post-concussive syndrome and may last as long as 12 weeks after head injury.
Intraparenchymal hemorrhage, or intracerebral hemorrhage, is a blood clot that develops within the brain substance. Intraparenchymal hemorrhages may occur after trauma and take the form of a frank blood clot or a contusion (bruise) within the brain. Traumatic intraparenchymal hemorrhages may occur at any age and are often observed in the lower anterior portions of the brain (anterior temporal lobe and anterior lower frontal lobe). Intraparenchymal hemorrhage may also develop spontaneously. Such hemorrhages are commonly a result of weakening of the blood vessels from hypertension. Other causes of spontaneous hemorrhages are arteriovenous malformations, tumors, or anticoagulants. Intraparenchymal hemorrhages often present with a stroke - an acute neurological deficit; or, if post-traumatic, with a neurological deficit after trauma. These lesions may also present with a simple, severe headache or with seizures. In severe cases, a patient may lapse immediately into a coma.
These hemorrhages are diagnosed usually by CT. In many cases of spontaneous intraparenchymal hemorrhage, an MRI is performed to evaluate possible presence of other lesions (tumors, etc.).
Often, these hemorrhages are surgically evacuated if the patient is in a coma, if the neurological deficit is severe, or if they are sizeable.
Skull fractures are breaks in the integrity of the skull bone. They most commonly result from a traumatic force. Skull fractures may occur in patients of all ages and with a variety of types of trauma including motor vehicle accidents, falls, and assaults. Skull fractures may be classified as: linear, skull fractures which are simple, straight breaks in the skull; depressed, skull fractures in which one end of the fracture plate is pushed beneath the other end; basilar, skull fractures which affect the bottom part of the skull adjacent to critical nerves; and open, skull fractures in which the skin is also traumatically lacerated over the fracture site allowing communication between the fracture and the outside. Skull fractures may be diagnosed by skull plain films or by computed tomography (CT). Linear skull fractures and mildly depressed skull fractures heal without surgical intervention. Severely depressed skull fractures and open skull fractures require surgical repair.
Spinal cord injury refers to acute, traumatic injury to the spinal cord and the associated neurological deficits thereafter. Spinal cord injury is almost always subsequent to trauma and spinal fractures. However, spinal cord injury may also occur due to compression of the cord from tumor or infection. Occasionally, arteriovenous malformations or thoracic aortic surgery may result in a spinal cord infarct with spinal cord injury. Spinal cord injury may occur at any age due to trauma, tumor, or infection. The symptoms of spinal cord injury depend on the level at which the cord is injured. If the cervical spinal cord is injured, the result is usually loss of motor and sensory function in the arms and legs (quadraparesis or quadraplegia). With cervical cord injuries, respiratory function may also be compromised requiring mechanical ventilation. Spinal cord injury at the thoracic or lumbar levels results in motor and sensory dysfunction in the legs (paraparesis or paraplegia). Either quadraplegia or paraplegia also may involve loss of bladder or bowel control with urinary or fecal incontinence. Also, quadraplegia may result in dysfunction in the sympathetic nervous system with reflex sympathetic dystrophy (an abnormal regulation of blood pressure and temperature). Loss of the sympathetic nervous may result in inability to maintain blood pressure or body temperature. Diagnosis of spinal cord injury is a clinical one based on history and neurological exam. MRI may assess the structural integrity of the spinal cord. Currently, no regenerative procedure exists to renew spinal cord function. Treatment is based on relieving compression on the cord through surgery. Early spinal cord injuries (within 8 hours) are also treated with high-dose intravenous methylprednisolone for 24 hours.
The spine is composed of segmental vertebral bones sandwiched around intervening discs. It has four segments: cervical, thoracic, lumbar, sacral. The spine acts as the load-bearing infrastructure in the body. Spine fractures may occur in the vertebrae as a result of traumatic forces or as a result of bone weakness due to tumor or infection. When fractures are due to tumors or infection, they are known as pathological fractures. Fractures may be associated with injury to the adjacent spinal cord, nerve roots, or cauda equina (the grouping of nerve roots at the end of the spinal cord). Such injuries may produce profound neurological deficits. Fractures are diagnosed using a combination of plain films, CT, and MRI, if an underlying spinal cord injury exists. Spinal fractures may result in an inability of the spine to bear loads. Such fractures are often termed unstable. Many fractures do not interfere with the load-bearing capacity of the spine and are deemed stable. Repair of many stable fractures is often through brace immobilization. The type of brace used depends on the type and region of fracture. Types of bracing are halo orthosis, cervical collar, sternal-occipital-mandibular (SOMI) orthosis, thoracolumbar-sacral orthosis (TLSO), amongst others. Unstable fractures often require surgical intervention to fuse the weakened segments.
Traumatic nerve injury most commonly results from sharp cuts, blunt bruising, stretching with or without breaking the nerve, gradual compression, or obliteration. When small nerves such as ones in the skin are cut, they recover by regrowing or have their function taken over by surrounding nerves. Peripheral nerves, unlike nerve cells in the brain, can regrow. Recovery is roughly dependent on the injured nerve's size and the amount of damage incurred. A slightly bruised nerve will usually recover function. A severed nerve may grow back together. A nerve that is shredded is less likely to regenerate completely. Aberrant regrowth of the nerves can result in oddities such as 'crocodile tears' where nerves which control the salivary glands accidentally grow to the tear glands causing tearing when eating or hungry. Injuries to large nerve branches can result in serious functional debility, such as the loss of motor function and/or sensation in extremity. Patients with these injuries should be referred to a surgeon who has training and experience in the anatomy and repair of peripheral nerves.