Altered Mental Status Answers 291blockade in cocaine poisoning leaves unopposed stimulated β-adrenergic
receptors, thus worsening vasoconstriction. Therefore, β-receptor blocker
use in cocaine poisoning is contraindicated. Acetaminophen (c)is not help-
ful in this situation. Fever or hyperthermia in cocaine poisoning is caused
by hypothalamic stimulation, and not because of inflammatory mediators.
Hyperthermia should be treated with cooling methods, such as cool mist
spray or ice-bath immersion. Lithium (d)is commonly used in the treat-
ment of depressive and bipolar affective disorders. It has no role in the acute
treatment of cocaine intoxication. Drug abuse specialists (e)should be con-
sulted when the patient is medically cleared.
268.The answer is c.(Tintinalli, p 1046.)The patient presents with a rare
but potentially life-threatening NMS. Antipsychotic drugs (eg, haloperidol)
are the most common offending agents in the development of NMS, caus-
ingcentral dopamine depletion.The disorder is typically characterized
byhyperthermia, muscle rigidity, altered mental status,andautonomic
instability.Since NMS carries a high mortality, it is important to aggres-
sively treat it with muscle relaxers, such as IV benzodiazepines, dantrolene,
and dopamine agonists.
Urinary tract infection (a)in a debilitated or nursing home patient can
easily lead to altered mental status and sepsis. The patient’s muscular rigidity,
however, does not fit this diagnosis. The presentation of malignant hyper-
thermia(b)is similar to NMS, also involving hyperthermia and muscle rigidity.
It is caused by anesthetic agents, which this patient did not receive. Dantro-
lene is also used for muscle relaxation in malignant hyperthermia. Recurrent
stroke (d)is unlikely in this presentation with hyperthermia and muscle
rigidity. Right-sided motor findings on examination are residual deficits from
the old stroke. Meningoencephalitis (e)is certainly high on the differential in
this patient but is unlikely to cause generalized muscular rigidity. It typically
presents with fever, headache, nuchal rigidity, altered mental status, and focal
neurologic signs.
269.The answer is e.(Tintinalli, p 1378.)The most likely diagnosis in
this patient is a space-occupying lesionin the frontal lobe of the brain.
Brain tumors can present with morning headaches associated with
nauseaand vomiting.Neurologic examination is normal in most patients.
Papilledema might provide an important clue of increased ICP and the
presence of a brain mass. Frontal lobe tumors typically involve personality
changesas seen in this patient.