Comprehensive Neurological Disorders: Intracranial Pressure, Cerebrovascular Accidents, Spinal Trauma, and Neuro-Emergencies

Comprehensive practice flashcards covering increased intracranial pressure, hemorrhagic stroke, head injuries, brain death, spinal cord trauma, neurogenic shock, autonomic dysreflexia, meningitis, Guillain-Barré syndrome, and status epilepticus.

According to the Monro-Kellie doctrine, what are the three components that make up intracranial volume and their respective normal proportions?

The three components are brain tissue ($78\%$), intravascular blood ($12\%$), and cerebrospinal fluid ($10\%$).

Under what condition is the Monro-Kellie doctrine applicable, and what is normal intracranial pressure (ICP)?

It is only applicable when the skull is closed (not in open fractures or penetrating wounds). Normal ICP is between $5\text{--}15\,\text{mmHg}$.

What is the most sensitive and earliest clinical indicator of increased intracranial pressure?

A change in the level of consciousness (LOC).

What three clinical manifestations comprise Cushing's triad in patients with increased intracranial pressure?

Widened pulse pressure (increasing systolic pressure with widening difference from diastolic), bradycardia, and irregular respirations.

How do decorticate and decerebrate posturing differ in presentation?

Decorticate posturing involves arms flexed and bent inward toward the chest with curled wrists and extended legs. Decerebrate posturing involves rigid, straight arms held parallel to the body with flexed wrists and extended legs.

What is cerebral herniation, and what type is demonstrated when tissue herniates through a surgical opening?

Cerebral herniation occurs when brain tissue is forcibly shifted from a compartment of greater pressure to one of lesser pressure. Extrusion through a skull opening is termed calvarial herniation through a craniectomy site.

How is brain injury severity classified according to Glasgow Coma Scale (GCS) total scores?

A score of $3\text{--}8$ indicates severe brain injury, $9\text{--}12$ indicates moderate brain injury, and $13\text{--}15$ indicates minor brain injury.

What is the gold standard device for measuring intracranial pressure, and where must its external transducer be leveled?

A ventriculostomy (catheter placed into the brain ventricles); the external transducer must be leveled precisely with the tragus of the patient's ear.

How does a normal intracranial pressure waveform compare to one indicating increased ICP?

A normal waveform resembles a descending staircase where peak $P1 > P2 > P3$. An abnormal waveform indicating increased ICP displays an elevation where $P2 > P1$.

Why is a lumbar puncture strictly contraindicated in patients with increased intracranial pressure?

Removing CSF from below creates a sudden pressure gradient that can pull brain tissue downward, causing fatal cerebral herniation into the brainstem.

What is the mechanism of action of mannitol (Osmitrol) in managing increased intracranial pressure?

It acts as an osmotic diuretic that creates an osmotic gradient, drawing fluid from the brain tissue into the vascular space to reduce ICP.

What nursing precautions must be taken regarding endotracheal suctioning in a patient with increased ICP?

Suctioning must be minimized, performed only when necessary, and restricted to no longer than $10\,\text{seconds}$ at a time, because it significantly increases ICP.

What is the most common cause of an intracerebral hemorrhage (ICH), and when does it most frequently occur?

Hypertension is the most common cause, and it occurs most often during periods of activity.

What are the four primary anatomical classifications of brain hemorrhage?

Epidural hematoma, subdural hematoma, subarachnoid hemorrhage, and intracerebral hemorrhage.

What clinical manifestations typically distinguish left-brain damage from right-brain damage following a stroke?

Left-brain damage causes right-sided hemiplegia, speech/language aphasias, cautious/slow behavior, and impaired comprehension. Right-brain damage causes left-sided hemiplegia, left-sided neglect, spatial deficits, impulsivity, and poor judgment.

How do endovascular coiling and surgical clipping treat a cerebral aneurysm?

Coiling involves inserting platinum coils into the aneurysm via a catheter to promote thrombosis and seal it off; clipping involves surgically placing a metal clip across the neck of the aneurysm to halt blood flow.

What class of medications is absolutely contraindicated in hemorrhagic stroke, and what is the systolic blood pressure target?

Anticoagulants/blood thinners are contraindicated; systolic blood pressure is managed within a normal to high range under $160\,\text{mmHg}$.

At what three time points does death commonly occur following a head injury?

Immediately after injury, within $2\,\text{hours}$ after injury (due to progressive bleeding), and approximately $3\,\text{weeks}$ after injury (due to multisystem failure).

What is the hallmark clinical presentation pattern of an epidural hematoma?

An initial brief period of unconsciousness, followed by a lucid interval where the patient is alert, followed by a rapid decline in consciousness due to arterial bleeding.

How do epidural and subdural hematomas differ in location and vascular source?

Epidural hematomas occur between the dura and inner skull and are typically arterial (fast-bleeding); subdural hematomas occur between the dura and arachnoid layer and are typically venous (slow-bleeding).

What distinguishes a coup injury from a contrecoup injury in closed head trauma?

A coup injury is the contusion occurring directly under the site of primary impact; a contrecoup injury occurs when the brain rebounds and strikes the opposite side of the skull.

What physical assessment signs indicate a basilar skull fracture with a cerebrospinal fluid (CSF) leak?

Periorbital ecchymosis (raccoon eyes), postauricular ecchymosis (Battle's sign), rhinorrhea, otorrhea, and the halo sign on drainage dressings.

What nursing interventions and restrictions are essential for a patient with a confirmed or suspected CSF leak?

Elevate the head of the bed, instruct the patient not to sneeze or blow their nose, and never insert a nasogastric (NG) tube or perform nasotracheal suctioning.

What three cardinal clinical criteria are required to make the diagnosis of brain death?

Coma or unresponsiveness, absence of brainstem reflexes, and apnea (absence of spontaneous respirations).

What are the four primary mechanisms of spinal cord injury illustrated in clinical trauma?

Flexion injury, hyperextension injury, compression fracture, and flexion-rotation injury.

What is the critical respiratory consequence of a spinal cord injury occurring above $C3$?

Total loss of respiratory muscle function, requiring immediate endotracheal intubation and mechanical ventilation to prevent respiratory arrest.

How do spinal shock and neurogenic shock differ in their clinical features?

Spinal shock causes temporary loss of deep tendon reflexes, sphincter reflexes, sensation, and flaccid paralysis below the injury. Neurogenic shock (at or above $T6$) is loss of sympathetic tone causing vasodilation, profound hypotension, and bradycardia.

What do grades A and E represent on the ASIA Impairment Scale for spinal cord injury?

Grade A represents complete injury (no motor or sensory function preserved at $S4\text{--}S5$); Grade E represents normal motor and sensory function in a patient with prior deficits.

What is the primary nursing priority regarding skin and frame care for a patient managed in a halo vest?

Providing meticulous pin site care to prevent infection and meningitis, inspecting the skin beneath the vest daily for breakdown, and maintaining spinal alignment without pulling on struts.

What triggers autonomic dysreflexia in patients with a spinal cord injury at or above $T6$, and what are its key signs?

The most common trigger is bladder distention (e.g., kinked catheter) or rectal impaction; manifestations include sudden severe hypertension, pounding headache, bradycardia, facial flushing, diaphoresis, and nasal congestion.

What are the immediate sequential nursing interventions for autonomic dysreflexia?

Elevate the head of the bed to at least $45^\circ$, assess and rapidly relieve the cause (check/un-kink Foley or catheterize, check for fecal impaction, loosen tight clothes), and notify the health care provider.

What is the classic clinical triad of bacterial meningitis?

Fever, severe headache, and nuchal rigidity (stiff neck), often accompanied by photophobia, nausea, and vomiting.

What sequence of diagnostic testing must be followed before performing a lumbar puncture in suspected bacterial meningitis?

A head CT scan must be performed before the lumbar puncture to rule out an intracranial mass or brain obstruction that could precipitate cerebral herniation.

What predominant white blood cell type is identified in the CSF analysis of a patient with bacterial meningitis?

Neutrophils are the predominant white blood cell.

What underlying pathophysiologic process characterizes Guillain-Barré syndrome (GBS)?

An autoimmune attack occurring days to weeks after an infection that causes demyelination and injury to peripheral nerve myelin sheaths and axons, exposing the nerve fiber.

What is the characteristic clinical pattern of weakness and paralysis in Guillain-Barré syndrome?

Acute, ascending, rapidly progressive, and symmetric flaccid weakness that begins in the lower extremities (feet and legs) and moves upward.

What are the first-line immunomodulating therapies for Guillain-Barré syndrome, and when are they most effective?

Plasmapheresis (plasma exchange) or high-dose intravenous immunoglobulin (IVIG); they are most effective when started within the first $2\,\text{weeks}$ of symptom onset.

How is status epilepticus (SE) defined clinically?

Any seizure lasting longer than $5\,\text{minutes}$, or recurrent seizures occurring so close together that the patient does not regain consciousness between episodes.

What medications are administered emergently as first-line treatment for status epilepticus?

Rapid-acting benzodiazepines: IV lorazepam if vascular access exists, or midazolam administered IM, buccal, or intranasally if IV access is absent.

What are the three anatomical classifications of spinal cord tumors, and what is their most common early symptom?

Extradural, intradural-extramedullary, and intramedullary; the most common early symptom is back pain.