CNRN flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Monro-Kellie hypothesis

The closed skull contains brain, blood, and cerebrospinal fluid in fixed total volume; an increase in one component must be offset by a decrease in another or intracranial pressure rises.

Cerebral perfusion pressure

CPP equals mean arterial pressure minus intracranial pressure. Normal adult CPP is commonly targeted at 60 to 70 mm Hg after severe traumatic brain injury.

Corticospinal tract function

The corticospinal tract carries voluntary motor commands from the motor cortex to the spinal cord; damage produces upper motor neuron weakness, increased tone, and hyperreflexia.

Cerebellum primary role

The cerebellum coordinates voluntary movement, balance, and posture; cerebellar lesions commonly cause ataxia, intention tremor, dysmetria, and wide-based gait.

Blood-brain barrier

Tight junctions between brain capillary endothelial cells restrict many large and hydrophilic molecules; lipid-soluble drugs and gases cross more readily into brain tissue.

Glasgow Coma Scale score

The Glasgow Coma Scale sums eye opening (1-4), verbal response (1-5), and motor response (1-6); total scores range from 3 to 15, with lower scores indicating worse consciousness.

Cushing triad

Cushing triad is hypertension with widened pulse pressure, bradycardia, and irregular respirations; it is a late sign of increased intracranial pressure and impending herniation.

Decerebrate posturing

Decerebrate posturing shows extended and internally rotated arms and extended legs; it suggests severe brainstem dysfunction and carries a worse prognosis than decorticate posturing.

ICP waveform P2

On an intracranial pressure waveform, P1 is percussion, P2 is tidal, and P3 is dicrotic; a P2 taller than P1 suggests poor intracranial compliance.

NIH Stroke Scale

The NIH Stroke Scale ranges from 0 to 42 and quantifies stroke deficits in consciousness, gaze, vision, motor function, sensation, language, and neglect; higher scores indicate greater severity.

Alteplase stroke dosing

For eligible ischemic stroke, alteplase dose is 0.9 mg/kg intravenous, maximum 90 mg; give 10% as a bolus and the remainder over 60 minutes.

Nimodipine after SAH

Nimodipine 60 mg is given orally or by nasogastric tube every 4 hours for 21 days after aneurysmal subarachnoid hemorrhage to reduce delayed cerebral ischemia.

Neurogenic shock

Neurogenic shock is hypotension with bradycardia caused by loss of sympathetic vascular tone after spinal cord injury; it differs from spinal shock, which is transient areflexia.

Autonomic dysreflexia

Autonomic dysreflexia occurs with spinal cord injury at T6 or above; noxious stimuli such as bladder distention cause severe hypertension, bradycardia, headache, and sweating.

Mannitol osmotic effect

Mannitol is an osmotic diuretic that pulls water from brain tissue into blood; monitor serum osmolality, sodium, renal function, and fluid balance because rebound edema can occur.

Multiple sclerosis pathology

Multiple sclerosis is immune-mediated demyelination of the central nervous system; common deficits include fatigue, optic neuritis, sensory loss, weakness, and bladder dysfunction.

Parkinson disease hallmark

Parkinson disease results from loss of dopaminergic neurons in the substantia nigra; cardinal signs are resting tremor, rigidity, bradykinesia, and postural instability.

Myasthenia gravis crisis

Myasthenic crisis is severe weakness from myasthenia gravis that causes respiratory failure or swallowing difficulty; monitor vital capacity and seek IVIG or plasma exchange.

Guillain-Barre syndrome

Guillain-Barre syndrome causes ascending symmetric areflexic weakness and can impair respiration; treat with IVIG or plasma exchange and monitor vital capacity.

Noncontrast CT head

Noncontrast head CT is first-line in acute neurological injury because it rapidly detects intracranial hemorrhage, fractures, mass effect, and hydrocephalus.

Lumbar puncture opening pressure

Normal lumbar puncture opening pressure in adults is about 10 to 20 cm of water; cerebrospinal fluid is sent for cell count, protein, glucose, and culture.

EEG status epilepticus

EEG identifies seizure activity and status epilepticus; continuous EEG is used when coma is unexplained or after cardiac arrest to detect nonconvulsive seizures.

Transcranial Doppler vasospasm

Transcranial Doppler detects vasospasm after subarachnoid hemorrhage by showing increased flow velocities in cerebral arteries; it is also used for sickle cell stroke screening.

Phenytoin therapeutic level

The usual therapeutic total phenytoin level is 10 to 20 mcg/mL; measure free phenytoin when albumin is low because total levels can underestimate active drug.

Levetiracetam renal dosing

Levetiracetam is cleared by the kidneys, so dose adjustment is required in renal impairment; common adverse effects include somnolence, irritability, and behavioral change.

Valproate major risks

Valproate is a broad-spectrum antiseizure drug associated with hepatotoxicity, pancreatitis, thrombocytopenia, and teratogenicity; monitor liver tests and platelet counts.

Carbamazepine adverse effects

Carbamazepine can cause hyponatremia from SIADH, agranulocytosis, and enzyme induction; monitor sodium and complete blood count during therapy.

Steroids for tumor edema

Corticosteroids reduce vasogenic edema around brain tumors; they are not recommended for traumatic brain injury or acute ischemic stroke because benefits are unproven.

EVD zero reference

An external ventricular drain is zeroed at the level of the tragus or external auditory meatus; keeping the prescribed height prevents over- or under-drainage of cerebrospinal fluid.

Aspiration after stroke

A bedside swallow screen is performed before oral intake after stroke; patients who fail or are not screened remain nothing by mouth to prevent aspiration pneumonia.

Restraint monitoring

Restraint use requires a written order, time limits, and frequent monitoring of circulation, skin, and safety; restraints are never tied to side rails.

ALARA radiation principle

ALARA means keeping radiation exposure as low as reasonably achievable; time, distance, and shielding reduce dose to patients and staff during neuroimaging.