Rationalize the use of mannitol in acute TBI. (SIGS 8.5a)
osmotic diuretic-- non-reabsorbable solute filtered by glomerulus causing water retention in PCT & dLoH-> alter Starling forces-> H20 leaves cells->decr ICP
Discuss the use of imaging in diagnosing head trauma and differentiate subdural from epidural hematoma (Sigs 8.5a)
non-contrast CT 1st; epidural: bright convex disc; subdural: crescent-shaped hemorrhage
Explain the risk of seizure and rationale for the use of fosphenytoin for seizure prophylaxis following TBI. (Sigs 8.5a)
H20-soluble prodrug metabol by plasma esterases->phenytoin->binds voltage-sensitive Na channel neuron->inhibit high-frequency repetitive action potentials
Describe the four main symptom clusters of PTSD. (SIGS 8.5b)
Criterion B: intrusion symp.; Criterion C: avoidance symp.; Criterion D: negative cognitions & mood; Criterion E: arousal & activity changes
Explain the role of sertraline in treating PTSD. (SIGS 8.5b)
(Zoloft)1st line monotherapy SSRI;inhibit serotonin reuptake via inhibition of SERT->incr. synaptic concentration serotonin CNS->enhanced serotonergic neurotran
List the DSM-5 criteria for diagnosing PTSD. (SIGS 8.5b)
traumatic situation-> reliving experience, avoidance, emotional detachment, incr. arousal, decr daily fx, >1 month
Identify risk and protective factors for suicide. (SIGS 8.6a)
risk: previous attempt, mental illness, social isolation, financial/legal/health problems, substance use, impulsive; protect: coping, religion, social support
Describe the mechanism of action of SSRIs and SNRIs. (SIGS 8.6a)
SSRI: inhibit 5-HT reuptake; SNRI: inhibit 5-HT & NE reuptake
Explain why the therapeutic effects of SSRIs are delayed. (SIGS 8.6a)
reuptake inhibition initially, but may require additional "downstream" effects to produce full therapeutic effect; modifies serotonergic receptors over weeks
Describe neurochemical changes thought to underlie the symptoms of schizophrenia. (SIGS 8.6b)
+ symp: incr subcortical release dopamine-> augments D2 recp activation&nucleus accumben;- symp: reduced D1 recp activation prefrontal cortex & nucleus caudatus
Describe how atypical antipsychotics treat symptoms of schizophrenia AND list adverse effects associated with these medications. (SIGS 8.6b)
transiently occupy D2 recep and rapidly dissociate to allow normal dopamine transmission; 2nd gen less potent D2 antagonists + antagonize 5HT2 recep to decr AE
Describe the brain circuits implicated in the symptoms of schizophrenia. (SIGS 8.6b)
Mesolimbic Tract: + symp; Mesocortical tract: - symp and cog/affect symp
List the symptoms of alcohol withdrawal and the timing of their presentation. (SIGS 8.7a)
tremors, vomiting, anxiety, sweating tachycardia-> gen. tonic-clonic seizures-> transient hallucinations-> delirium tremens
Define delirium tremens. (SIGS 8.7a)
persistant alteration of consciousness and sympathetic hyperactivity due to alcohol withdrawal
Describe withdrawal seizures. (SIGS 8.7a)
onset 8-48 hours after cessation/reduction alcohol; usually brief, generalized tonic-clonic seizures; often single episode
Explain the role of benzodiazepines in the management of alcohol withdrawal. (SIGS 8.7b)
binds "benzodiazepine receptors" between alpha and gamma subunits of GABA-A-> incr freq. of chloride channel opening -> incr inhibitory effect of GABA
