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Neurosurgical Emergencies. Frank Culicchia MD Department of Neurosurgery LSUHSC New Orleans. Symptoms and Signs of Elevated ICP. Triad Headache, nausea, vomiting Cranial nerve palsies Papilledema Vital sign changes Cushing’s Arterial hypertension and bradycardia Respiratory changes.
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Neurosurgical Emergencies Frank Culicchia MD Department of Neurosurgery LSUHSC New Orleans
Symptoms and Signs of Elevated ICP • Triad • Headache, nausea, vomiting • Cranial nerve palsies • Papilledema • Vital sign changes • Cushing’s • Arterial hypertension and bradycardia • Respiratory changes
Papilledema • Swelling of the optic nerve head with engorgement of the retinal veins • May be accompanied by hemorrhages into the nerve and adjacent retina • Presence almost always indicates raised intracranial pressure.
PathophysiologySecondary Injury • Increased intracranial pressure • Severity of injury tends to increase due to heightened ICP, especially if pressure exceeds 40 mm Hg (remember CPP) • Increased pressure also can lead to cerebral hypoxia, cerebral ischemia, cerebral edema, hydrocephalus, and brain herniation • Monro-Kellie doctorine • In 1783 Alexander Monro deduced that the cranium was a "rigid box" filled with a "nearly incompressible brain" and that its total volume tends to remain constant. The doctrine states that any increase in the volume of the cranial contents (e.g. brain, blood or cerebrospinal fluid), will elevate intracranial pressure. Further, if one of these three elements increase in volume, it must occur at the expense of volume of the other two elements. In 1824 George Kellie confirmed many of Monro's early observations.
Cerebral Perfusion Pressure CPP= MABP-ICP Normal approximately 55 Children tolerate lower CPP than elderly
PathophysiologySecondary Injury • Monro-Kellie Doctrine (modified) • v.intracranial (constant) = v.brain + v.CSF + v.blood + v.mass lesion • Normally: brain 80%, CSF 10%, Blood 10% • Temperature, MABP, CPP, positioning, resistance, etc.
PathophysiologySecondary Injury • Cerebral Edema • caused by effects of neurochemical transmitters and by increased ICP • Disruption of the blood brain barrier, with impairment of vasomotor autoregulation leading to dilatation of cerebral blood vessels • Types of cerebral edema • Vasogenic • Cytotoxic • Transependymal
PathophysiologySecondary Injury • Brain Herniation • Supratentorial herniation is due to direct mechanical compression by an accumulating mass or to increased intracranial pressure • 3 types of supratentorial herniation are recognized • Subfalcine herniation: The cingulate gyrus of the frontal lobe is pushed beneath the falx cerebri when an expanding mass lesion causes a medial shift of the ipsilateral hemisphere. This is the most common type of herniation • Central transtentorial herniation: characterized by displacement of the basal nuclei and cerebral hemispheres downward while the diencephalon and adjacent midbrain are pushed through the tentorial notch • Uncal herniation: displacement of the medial edge of the uncus and the hippocampal gyrus medially and over the ipsilateral edge of the tentorium cerebelli foramen, causing compression of the midbrain, while the ipsilateral or contralateral third nerve may be stretched or compressed
PathophysiologySecondary Injury • Cerebellar Herniation • infratentorial herniation in which the tonsil of the cerebellum is pushed through the foramen magnum and compresses the medulla, leading to bradycardia and respiratory arrest
PathophysiologySecondary Injury • Hydrocephalus • communicating type is more common which frequently is due to the presence of blood products causing obstruction to flow of the cerebral spinal fluid (CSF) in the subarachnoid space and absorption of CSF through the arachnoid villi • noncommunicating type of hydrocephalus often caused by blood clot obstruction of CSF flow at the interventricular foramen, third ventricle, cerebral aqueduct, or fourth ventricle
Management of Elevated ICP: Interventions • Airway/ventilator support • Maintain adequate CPP • Osmotic diuresis • Hypertonic saline • Sedation/analgesia • Hypothermia • Neuromuscular blockade • Barbiturate coma • Glycemic control • CSF drainage • Craniectomy
CNS Infections • Meningitis • Abcess • Brain • Spinal cord • Subdural • Epidural • Encephalitis
CNS Infections: Signs and Symptoms • Meningismus • Nuchal rigidity • Headache • Photophobia • Fever • Lethargy
CNS Infections: Cause Bacterial Viral Fungal Parasites Prions
CNS Infections: Pathophysiology • Hematogenous • Originate from infection elsewhere in the body • Respiratory • Endocarditis • Direct extension • Sinus infections • Osteomyelitis • Trauma or surgery
Meningitis Viral meningitis causes milder symptoms, requires no specific treatment, and resolves without complications Bacterial meningitis is a very serious disease and may result in a learning disability, hearing loss, permanent brain damage, and even death Viral infections are 2-3 times more common.
Meningitis Overall incidence of bacterial meningitis in US is estimated to be more than 400 per 100,000 newborn babies, and 1-10 cases per 100,000 adults per year, or 25,000 cases yearly Approximately two-thirds of all cases are in children Usually occurs in isolated cases without epidemics More common in males than females More likely in late winter and early spring
Meningitis • Three types of bacteria are the most common causes of meningitis in all age groups except newborns: • Streptococcus pneumonia (causing pneumococcal meningitis) • Neisseria meningitidis (causing meningococcal meningitis) • Haemophilus influenza type b (Hib) • Hib vaccine as part of routine pediatric immunization has significantly reduced the occurrence of serious Hib disease • Newborns are usually infected with coliform (bacteria in the gut, contracted at birth) such as Escherichia coli or Listeria and Group B Strep
Types of Primary TBI • Skull fracture • vault or basilar • hematoma, cranial nerve damage, and increased brain injury • compound vs. simple; open vs. depressed
Types of Primary TBI • Intracranial Hemorrhages • Epidural hematoma • impact loading to the skull with associated laceration of the dural arteries or veins, often by fractured bones and sometimes by diploic veins in the skull's marrow • most common, a tear in the middle meningeal artery causes this type of hematoma. When hematoma occurs from laceration of an artery, blood collection can cause rapid neurologic deterioration • Subdural hematoma • tends to occur in patients with injuries to the cortical veins or pial artery in severe TBI, with associated mortality rate approximately 60-80%