Diagnostic features:
(1) The patient experiences episodes of uncontrollable laughter and/or crying.
(2) The episodes are inappropriate, incongruent or excessive for the situation.
(3) The patient is aware that the laughter and/or crying is inappropriate and out of character.
(4) The patient has an underlying neurologic disorder.
(5) The episodes result in personal distress and/or functional impairment.
(6) A mood disorder has been excluded as the sole underlying factor.
Situational analysis - the laughter or crying:
(1) occurs spontaneously without a precipitating cause
(2) has an intensity or duration that is excessive for any identifiable cause
(3) is incongruous for the situation (for example, laughter at a significant personal loss)
Underlying neurologic disorder may include:
(1) multiple sclerosis
(2) amyotrophic lateral sclerosis (ALS)
(3) Parkinson's disease
(4) multiple system atrophy
(5) stroke
Mood disorders which need to be considered:
(1) bipolar disorder
(2) major depression
(3) psychosis
(4) neurosis
A person with a neurologic condition that can result in pathologic laughing/crying may also have one of the listed mood disorders.