LSUHSC New Orleans Department of Neurosurgery Neurosurgical Emergencies Frank Culicchia MD Department of Neurosurgery LSUHSC New Orleans LSUHSC New Orleans Department of Neurosurgery 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 LSUHSC New Orleans Department of Neurosurgery 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. LSUHSC New Orleans Department of Neurosurgery Pathophysiology Secondary 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. LSUHSC New Orleans Department of Neurosurgery Cerebral Perfusion Pressure CPP= MABP-ICP Normal approximately 55 Children tolerate lower CPP than elderly LSUHSC New Orleans Department of Neurosurgery Pathophysiology Secondary 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. LSUHSC New Orleans Department of Neurosurgery Pathophysiology Secondary 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 LSUHSC New Orleans Department of Neurosurgery Cerebral Autoregulation LSUHSC New Orleans Department of Neurosurgery Assessment of Autoregulatory Reserve LSUHSC New Orleans Department of Neurosurgery Pathophysiology Secondary 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 LSUHSC New Orleans Department of Neurosurgery Pathophysiology Secondary 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 LSUHSC New Orleans Department of Neurosurgery Pathophysiology Secondary 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 LSUHSC New Orleans Department of Neurosurgery Management of Elevated ICP: Interventions Airway/ventilator support Hypothermia Maintain adequate CPP Neuromuscular blockade Osmotic diuresis Hypertonic saline Sedation/analgesia Barbiturate coma Glycemic control CSF drainage Craniectomy LSUHSC New Orleans Department of Neurosurgery Therapeutic Modalities for Reduction of ICP LSUHSC New Orleans Department of Neurosurgery CNS Infections Meningitis Abcess Brain Spinal cord Subdural Epidural Encephalitis LSUHSC New Orleans Department of Neurosurgery CNS Infections: Signs and Symptoms Meningismus Nuchal rigidity Headache Photophobia Fever Lethargy LSUHSC New Orleans Department of Neurosurgery CNS Infections: Cause Bacterial Viral Fungal Parasites Prions LSUHSC New Orleans Department of Neurosurgery CNS Infections: Pathophysiology Hematogenous Originate from infection elsewhere in the body Respiratory Endocarditis Direct extension Sinus infections Osteomyelitis Trauma or surgery LSUHSC New Orleans Department of Neurosurgery 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. LSUHSC New Orleans Department of Neurosurgery 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 LSUHSC New Orleans Department of Neurosurgery 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 LSUHSC New Orleans Department of Neurosurgery Brain Abcess LSUHSC New Orleans Department of Neurosurgery Types of Primary TBI Skull fracture vault or basilar hematoma, cranial nerve damage, and increased brain injury compound vs. simple; open vs. depressed LSUHSC New Orleans Department of Neurosurgery Depressed Skull Fracture LSUHSC New Orleans Department of Neurosurgery Depressed Skull Fracture LSUHSC New Orleans Department of Neurosurgery Depressed Skull Fracture LSUHSC New Orleans Department of Neurosurgery Depressed Skull Fracture LSUHSC New Orleans Department of Neurosurgery 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% LSUHSC New Orleans Department of Neurosurgery Acute Subdural Hematoma LSUHSC New Orleans Department of Neurosurgery Acute Subdural Hematoma LSUHSC New Orleans Department of Neurosurgery Acute Subdural Hematoma LSUHSC New Orleans Department of Neurosurgery Acute Subdural Hematoma LSUHSC New Orleans Department of Neurosurgery Epidural Hematoma LSUHSC New Orleans Department of Neurosurgery Epidural Hematoma LSUHSC New Orleans Department of Neurosurgery Epidural Hematoma