CASE Worsening outbursts and emotional lability
Mr. X, age 16, has cerebral palsy (CP), idiopathic normal pressure hydrocephalus (iNPH), and a history of impulse control disorder and behavioral instability, including episodes of aggression or combativeness. Mr. X’s mother reports that these episodes are almost always preceded by inappropriate laughing or crying. His outbursts and emotional lability have gotten worse during the last 6 months. Due to his disruptive behaviors, Mr. X has been unable to attend school, and his parents are considering group home placement. Although they were previously able to control their son’s aggressive behaviors, they fear for his safety, and after one such episode, they call 911. Mr. X is transported by police in handcuffs to the comprehensive psychiatric emergency room (CPEP) for evaluation.
While in CPEP, Mr. X remains uncooperative and disruptive; subsequently, he is placed in 4-point restraints and given haloperidol, 10 mg IM, and lorazepam, 2 mg IM, to prevent harm to himself or others. After 2 hours, he is unable to maintain a reality-based conversation but has become semi-cooperative. Mr. X’s mother decides to take him home and immediately makes an appointment with his outpatient psychiatrist.
The authors’ observations
Pseudobulbar affect (PBA) is a disorder characterized by sporadic episodes of inappropriate laughing and/or crying that are incongruent with situational context and are frequently exaggerated in comparison with the actual feelings of the patient. The duration of PBA episodes can last seconds to minutes and arise unpredictably.
PBA typically develops secondary to a neurologic disorder, most commonly Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), Parkinson’s disease (PD), stroke, or traumatic brain injury (TBI).1 PBA symptoms are present in an estimated 29.3% of patients with AD, 44.8% of patients with ALS, 45.8% of patients with MS, 26% of patients with PD, 37.8% of patients with stroke, and 52.4% of patients with TBI.2 Although PBA appears far more frequently in patients with MS or ALS compared with those with PD, PD represents an under-recognized and larger patient population. A small fraction of patients also develops PBA secondary to hyperthyroidism, hypothyroidism, Graves’ disease, Wilson’s disease, brain tumors, and a multitude of encephalopathies.3 These neurologic disorders cause dysregulation of the corticopontine-cerebellar circuitry, resulting in functional impediment to the normal affect modulator action of the cerebellum.4
The neurologic insults that can result in PBA may include CP or iNPH. Cerebellar injury is a frequent pathological finding in CP.5 In patients with iNPH, in addition to altered CSF flow, enlarged ventricles compress the corticospinal tracts in the lateral ventricles,6 which is theorized to induce PBA symptoms.
PBA is diagnosed by subjective clinical evaluation and by using the Center for Neurologic Study–Lability Scale (CNS-LS). The CNS-LS is a 7-question survey that addresses the severity of affect lability (Table 17). It may be completed by the patient or caregiver. Each question ranges in score from 1 to 5, with the total score ranging from 7 to 35. The minimum score required for the diagnosis of PBA is 13.7
PBA is frequently misdiagnosed as depression, although the 2 disorders can occur simultaneously (Table 21,8). A crucial distinguishing factor between depression and PBA is the extent of symptoms. Depression presents as feelings of sadness associated with crying and disinterest that occur for weeks to months. In contrast, PBA presents as brief, uncontrollable episodes of laughing and/or crying that last seconds to minutes. Unlike depression, the behaviors associated with PBA are exaggerated or do not match the patient’s feelings. Furthermore, a neurologic disease or brain injury is always present in a patient with PBA, but is not imperative for the diagnosis of depression.
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