Neuroleptic Malignant Syndrome Flashcards
(39 cards)
what is NMS
life threatening idiosyncratic reaction to DOPAMINE ANTAGONISTS (most commonly antipsychotics but not always just antipsychotics)
what are the characteristic features of NMS
fever
altered mental status
muscle rigidity
autonomic dysfunction
what is the hypothesized underlying mechanism of NMS
excessive dopamine receptor blockade
what is the incidence of NMS
0.01-0.02% among those treated with antipsychotics
how soon does NMS develop after drug initiation
most develop within first 24 hours of drug initiation
may be within first week
virtually all cases are within first 30 days
what is the fatality rate of NMS
10-20% when UNrecognized
what is the mean recovery time after drug discontinuation
7-10 days
most people recover within 1 week and nearly all within 30 days
residual neurological signs may persist for weeks after the acute hyper metabolic symptoms resolve
do people tend to have recurrences of NMS?
people generally do NOT experience a recurrence of NMS when re-challenged with an antipsychotic
but theoretically there is a risk
list risk factors for NMS
agitation
exhaustion
dehydration
iron deficiency
parenteral administration of drug
rapid titration
higher total drug doses (though most cases occur within the dose range)
what types of antipsychotics present greater risk of NMS
higher potency are higher risk
what other types of drugs, other than antipsychotics, could cause NMS
ANY dopamine antagonist–> i.e metoclopramide or prochloperazine
can also see it in those with parkinsons disease if there is withdrawal of L-dopa or dopamine agonist therapy, dose reductions or a switch from one dopamine agonist to another
how are NMS and catatonia related
NMS related to malignant catatonia–> NMS being iatrogenic form of malignant catatonia
is there consensus or diagnostic criteria for NMS
no–> there was proposed criteria by a “2011 international consensus study of NMS diagnostic criteria”
what is a mnemonic to remember the clinical and lab findings of NMS
FEVERR
Fever
Encephalopathy (confusion, mental status changes)
Vital sign instability (tachycardia, tachypnea, and/or labile BP)
Enzyme elevation (creatinine phosphokinase increase due to rhabdo)
Rhabdomyolysis (caused by muscle rigidity)
Rigidity (generalized lead pipe muscle rigidity)
what feature distinguishes NMS from other toxidromes like serotonin syndrome and anticholinergic toxicity
muscle rigidity often leading to rhabdo
what are the 8 proposed diagnostic criteria mentioned previously
- recent dopamine agonist withdrawal or dopamine antagonist exposure (within last 72 hours)
- hyperthermia (above 38 on at least two oral measurements)
- rigidity (lead pipe)
- mental status alteration (reduced or fluctuating LOC)
- CK elevation
- sympathetic nervous system lability (defined by at least two of: BP elevation 25% or more above baseline; BP fluctuation of 20mmHg systolic change within 24 hours; diaphoresis; urinary incontinence)
- hypermetabolism (HR increase 25% or more above baseline AND respiratory rate increase of 50% or more above baseline)
- negative workup for infectious, toxic, metabolic or neurologic causes
what amount of CK elevation is expected in NMS
at least 4x upper limit of normal
what features do you look for in terms of assessing sympathetic nervous system instability when assessing for NMS
defined by at least two of:
BP ELEVATION 25% or more above baseline
BP FLUCTUATION of 20mmHg systolic change within 24 hours
diaphoresis (often profuse)
urinary incontinence
what features do you look for in terms of assessing hypermetabolism when assessing for NMS
HR increase of 25% or more above baseline
RR increase of 50% or more above baseline
what other neuro signs can be present with NMS
tremors
trismus
dysarthria
dysphagia
akinesia
sialorrhea
myoclonus
what might you see on EEG for NMS
generalized slowing
what might you see on blood work for someone with NMS
leukocytosis
metabolic acidosis
hypoxia
decreased serum iron concentrations
elevations in serum muscle enzymes and catecholamines
does NMS show up on CSF analysis or neuroimaging studies
no–> these are generally unremarkable in NMS
how do you make the diagnosis of NMS
diagnosis of exclusion
must exclude other infectious, toxic, metabolic and neuropsychiatric conditions i.e status epilepticus
