Reading guide 2 Parkinson’s/seizures etc Flashcards
Blood brain barrier
The blood-brain barrier refers to the unique structure and function of CNS capillaries, which act as a selective filter and protects the CNS by limiting the substances that enter the brain and spinal cord.
How does the blood brain barrier influence pharmacology?
Certain substances are not able to pass from the bloodstream into the CNS, even though these substances are able to pass without difficulty from the systemic circulation into other peripheral tissues. Require facilitated or active transport for drugs to cross into the CNS to have their intended effect.
ACH, norepinephrine, dopamine, serotonin, GABA (gamma aminobutyric acid), glycine, glutamate, aspartate, substance P, enkephalins are all ______
central neurotransmitters
Quality of evidence
Level A
- High-quality evidence from more than 1 RCT
- Meta-analyses of high-quality RCTs
- One or more RCTs corroborated by high-quality registry studies
Quality of evidence
Level B-R (randomized)
- Moderate-quality evidence from 1 or more RCTs
- Meta-analyses of moderate-quality RCTs
Quality of evidence
Level B - NR (non randomized)
- Moderate-quality evidence from 1 ore more well-designed, well-executed nonrandomized studies, observational studies, or registry studies
- Meta-analyses of such studies
Quality of evidence
Level c - LD (limited data)
- Randomized or nonrandomized observational or registry studies with limitations of design or execution
- Meta-analyses of such studies
- Physiological or mechanistic studies in human subjects
Quality of evidence
Level C -EO (expert opinion)
Consensus of expert opinion based on clinical experience
What are the components of the NIHSS and what is it used for?
The components of the NIHSS are level of consciousness, orientation, response to commands, gaze, visual fields, facial movements, motor functions of R and L arms, motor functions of L and R legs, limb ataxia, sensory, language, articulation, and extinction/inattention. This scale is used to provide a standardized scale that quantifies the degree of neuro deficits, communication, help patients for intervention, allow objective measurements, and identifies those who are at a higher risk for complication.
What are the imaging recommendations for people with acute ischemic stroke?
The imaging recommendations for people with acute ischemic stroke are emergency brain images before any specific treatments are initiated. This would include noncontrast CT (NCCT), MRIs, and CTA with CTP or MR angiography with diffusion-weighted MRI.
What are the recommendations for blood pressure before fibrinolytic therapy?
The recommendation for BP before fibrinolytic therapy is that their systolic BP is below 185 mmHg and their diastolic BP is below 110 mmHg.
What is the ideal time window for IV alteplase administration?
The ideal time window for IV alteplase administration is within 4.5 hours of stroke symptom recognition.
What is IV alteplase?
is a thrombolytic drug used to dissolve blood clots in blood vessels. It’s administered intravenously in the arm to treat acute ischemic stroke (AIS) and acute myocardial infarction (AMI). Alteplase works by converting plasminogen into plasmin, a proteolytic enzyme that breaks down fibrin and fibrinogen. It can reduce platelet aggregation and improve blood flow and tissue ischemia
What are the recommendations for aspirin administration in patients with acute ischemic stroke?
The recommendation for aspirin administration in patients with acute ischemic stroke are within 24-48 hours after onset of AIS
Medical management of stroke
- Improve cerebral perfusion by reestablishing circulation and oxygenation and assist in stopping progression of the lesion to limit deficits. Oxygen is delivered via mask or nasal cannula. Patients in a coma may require intubation or assisted ventilation and suctioning.
- Maintain adequate BP. Hypotension or extreme hypertension is treated; antihypertension agents have the added risk of inducing hypotension and decreasing cerebral perfusion.
- Maintain sufficient cardiac output. If the causes of stroke are cardiac in origin, medical management focuses on control of arrhythmias and cardiac decompensation.
- Restore/maintain fluid and electrolyte balance.
- Maintain blood glucose levels within the normal range.
- Control seizures and infections.
- Control edema, intracranial pressure, and herniation using antiedema agents. Ventriculostomy may be indicated to monitor and drain cerebrospinal fluid.
- Maintain bowel and bladder function, which may include urinary catheter. Catheterization is typically short term but may be long term with the patient in coma.
- Maintain integrity of skin and joints by instituting protective positioning, a turning schedule every 2 hours, and early physical and occupational therapy.
- Decrease the risk of complications such as DVT, aspiration, pressure injuries, and so forth.
Neurosurgical management of stroke
- In hemorrhagic stroke, surgery may be indicated to repair a superficial ruptured aneurysm or AVM, prevent rebleeding, and evacuate a clot (hematoma). Larger, deeper intracranial or brain stem vascular lesions are generally not amenable to surgery. Surgery may also be indicated for resection of a superficial unruptured AVM when there is high risk of rupture and stroke.
- Mechanical thrombectomy is the removal of a large blood clot by sending a stent retriever to the site of the blocked blood vessel in the brain. To remove the brain clot, a catheter is threaded through an artery in the groin up to the blocked artery in the brain where the clot is removed. The procedure should be done within 6 hr of acute stroke symptoms, and only after a patient receives tPA.
- Carotid endarterectomy is a surgical procedure used to remove fatty deposits from the carotid artery. It is a useful procedure to prevent recurrent strokes or the development of stroke in individuals with TIAs. Stenosis of 60% to 99% is the typical guideline used when surgery is considered and can reduce stroke risk by as much as 55%. It cannot be performed with acute stroke because altered pressures could subject ischemic areas to further damage.
Examples of thrombolytics
alteplase and gene template (activate or tPA)
examples of meds commonly used to treat patients with stroke
thrombolytics, anticoagulants (warfarin - coumadin), antiplatelet therapy (aspirin), antihypertensive agents (ACE inhibitors / alpha blockers), angiotensin II receptor antagonists, anticholesterol agents / statins (Lipitor), antispasmodics / spasmolytics (soma), antispastics (dantrolene sodium, Valium), anticonvulsants, gaba, neurotoxins, antidepressants
- Antidepressants
e.g., fluoxetine [Prozac], monoamine oxidase inhibitors, sertraline [Zoloft], tricyclics [Amitriptyline]):
Used to control depression.
Possible adverse effects: May cause anxiety, tremor, insomnia, nausea.
- Neurotoxins
e.g., botulinum toxin [Botox]):
Interact with proteins in nerves to relax muscles.
Possible side effects: Pain or swelling at site of injection, drowsiness.
- GABA (gamma-amino butyric acid) receptor antagonists
e.g., baclofen [Kemstro, Lioresal]):
Inhibit the action of GABA, which inhibits neurotransmitters and regulates the nervous system. May be used to manage spasticity.
Possible side effects: Drowsiness, dizziness, or headache.
- Anticonvulsants
e.g., carbamazepine [Tegretol], clonazepam [Klonopin], diazepam [Valium], phenobarbital [Luminal], phenytoin [Dilantin]):
Used to control seizures; act as a generalized central nervous system depressant.
Possible adverse effects: May cause drowsiness, ataxia, sedation, among other symptoms.
Antispastics
(e.g., baclofen [Lioresal], dantrolene sodium [Dantrium], diazepam [Valium], tizanidine [Zanaflex]):
Used to relax skeletal muscle and decrease muscle spasm.
Possible adverse effects: May cause drowsiness, dizziness, confusion, weakness, among other symptoms.
- Antispasmodics/spasmolytics
(e.g., carisoprodol [Soma], chlorzoxazone [Parafon Forte], cyclobenzaprine [Flexeril], diazepam [Valium], methocarbamol [Robaxin], orphenadrine [Norflex/Norgesic]):
Used to relax skeletal muscle and decrease muscle spasm.
Possible adverse effects: May cause drowsiness, dizziness, dry mouth, among other symptoms.
