Transcript Neurons
Block 2 Neuro Concepts CARE OF PATIENTS WITH PROBLEMS OF THE CENTRAL NERVOUS SYSTEM: THE BRAIN BLOCK 2 FEATURED DISORDERS SEIZURES & EPILEPSY MENINGITIS & ENCEPHALITIS What is the Role of Neurons? Neurons (also called nerve cells and nerve fibers) are electrically excitable cells in the nervous system that function to process and transmit information Neurons are the core components of the brain, spinal cord and peripheral nerves Motor Neurons cause movement or mobility Sensory Neurons cause sensation Some neurons process information and some retain Impulses from one neuron to another may cause excitation or inhibition Basic Structure of Neurons Speed Neuron Review When a neuron receives an impulse from another neuron, the impulse may be excitation of inhibition as mentioned in previous slide Afferent neurons also known as sensory neurons, are specialized to send impulses toward the CNS away from the PNS Efferent neurons are motor nerve cells that carry signals from the CNS to the cells in the PNS Impulses are transmitted to their destinations through the spaces between neurons Two distinct types of synapses are neuron-to-neuron or neuron-to-muscle (or gland) Seizure versus Epilepsy Seizure: an abnormal, sudden, excessive, uncontrolled electrical discharge of neurons within the brain that may result in a change in level of consciousness (LOC), motor or sensory ability, and/or behavior, generalized or partial Epilepsy: is defined by the National Institute of Neurological Disorders and Stroke as two or more seizures experienced by a person- distinguished by different characteristics Epilepsy Type Primary or idiopathic: no known cause, but genetic link Secondary: known cause for example, tumor, injury, infection Seizure/Epilepsy Diagnosis EEG CT or MRI Labs Seizure Risks May result from: Metabolic disorders Acute alcohol withdrawal Electrolyte disturbances Heart disease High fever Stroke Substance abuse Enrichment Info Ethanol is a CNS depressant Euphoria & behavior excitation at low levels Acute intoxication at higher levels causes drowsiness, ataxia, slurred speech, stupor and coma Short-term effects of ETOH are actions on certain ions Prolonged consumption leads to tolerance & physical dependence because ion function changes Abrupt cessation of ETOH with prolonged ETOH consumption unmasks the ion changes & leads to ETOH withdrawal syndrome Withdrawal includes blackouts, tremors, muscular rigidity, delirium tremors AND SEIZURES Seizure Assessment Questions: Ask patient or relative how many, how long they last and any patterns Describe movement Any aura? (pre-ictal phase) Medications Any risks? Seizure Precautions Oxygen Suction equipment Airway IV access Siderails up Seizure Management Depends on type of seizure Observation and documentation Patient safety Side-lying position No restraints Nothing in mouth Acute Seizure Management Lorazepam (Ativan) Diazepam (Valium) IV phenytoin (Dilantin) or fosphenytoin (Cerebyx) Drug Therapy Evaluate most current blood level of medication, if appropriate Be aware of drug-drug/drug-food interactions Maintain therapeutic blood levels for maximal effectiveness Do not administer warfarin with phenytoin Document and report side/adverse effects Surgical Management Nerve stimulation (VNS) Conventional surgical procedures Anterior temporal lobe resection Status Epilepticus Prolonged seizures that last more than 5 min or repeated seizures over course of 30 min – Establish airway ABGs IV push lorazepam or diazepam Rectal diazepam Loading dose IV phenytoin Patient & Family Education Compliance with medication Discrimination prohibited (ADA) Alternative employment may be needed Meningitis Meningitis: is an inflammation of the meninges that surround the brain and spinal cord Block 2: Viral Bacterial Physical Assessment & Clinical Manifestations Question predisposing history: infections, procedures or injuries? General symptom Fever Neurological symptoms Headache Photophobia Indications of increased ICP Nuchal rigidity Positive Kernig’s, Brudzinski’s signs Decreased mental status Focal neurological deficits GI symptoms Nausea and vomiting Laboratory Assessment of Meningitis CSF analysis (lumbar puncture) CT scan Blood cultures CBC X-rays to determine presence of infection Key Assessment Priority: Decreased (or change in) level of consciousness Priority: Disoriented to person, place, and year Pupil reaction and eye movements: Photophobia Nystagmus Abnormal eye movements Motor response: Normal early in disease process Hemiparesis, hemiplegia & later decreased muscle tone possible Key Assessment Continued Cranial nerve dysfunction, especially CN III, IV, VI, VII, VIII Memory changes: Attention span (usually short) Personality and behavior changes Bewilderment Severe, unrelenting headaches Generalized muscle aches and pain Nausea and vomiting Fever and chills Tachycardia Red macular rash (meningococcal meningitis) Drug Therapy Broad-spectrum antibiotic (one exampleVancomycin) Hyperosmolar agents (example- mannitol) Anticonvulsants (control seizures) Steroids (controversial) Barbituates (drug induced coma) Prophylaxis antibiotic treatment for those in close contact with meningitis-infected patient Patient Care ABC VS & Neuro Checks Cranial Nerve Assessment- particularly III, IV, VI, VII, and VIII Meds I&O Labs Bedrest & HOB 30 degrees Nurse safety- standard & droplet isolation with bacterial meningitis Encephalitis Inflammation of brain tissue and surrounding meninges Affects cerebrum, brainstem and cerebellum Viral agent most common but also bacteria, fungi, or parasites (example malaria is a parasite transmitted form bites of mosquitos) Virus travels to CNS via bloodstream, along peripheral or cranial nerves or meninges (varicella zoster) Inflammatory response but no exudate NursingDrug therapy- no specific meds for aborviruses or enteroviruses, but acyclovir is used for herpes encephalitis Complications-permanent neuro damage Encephalitis Pathophysiology-refer to lecture prep notes Causes-refer to lecture prep notes Preventative measures-control mosquitos Physical assessment- The patient may be lethargic, stuporous, or comatose Mental status changes are more extensive in the patient with encephalitis than with meningitis. Changes include acute confusion, irritability, and personality and behavior changes (especially noted in the presence of herpes simplex) NursingDrug therapy- no specific meds for aborviruses or enteroviruses, but acyclovir is used for herpes encephalitis Complications-permanent neuro damage Encephalitis Management Nursing Management: similar to meningitis but meds are different Drug therapy- no specific meds for aborviruses or enteroviruses, but acyclovir is used for herpes encephalitis Complications-permanent neuro damage Hemorrhagic Encephalitis