Subject(s)
Aphasia, Conduction/diagnosis , Arcuate Nucleus of Hypothalamus/injuries , Blast Injuries/diagnosis , Brain Injuries/diagnosis , Diffusion Magnetic Resonance Imaging , Explosions , Adult , Aphasia, Conduction/etiology , Brain Injuries/etiology , Humans , Male , Military Personnel , Tomography, Emission-ComputedABSTRACT
Emotional instability (EI) is involuntary laughing and crying associated with brain damage seen in a variety of disorders. This article discusses occurrence, impact, and diagnosis, and neuroanatomic substrates underlying proposed mechanisms producing EI are outlined and related to traditional drug treatment. An expanded neuroanatomic model is suggested emphasizing the prefrontal cortex as the center integrating information from a complex emotion and sensory loop with motor information destined for the faciorespiratory nuclei in the brainstem. Disturbance at any level in the loop is proposed to produce EI by degrading information to or from the prefrontal cortex, disrupting its inhibitory control of the nuclei. An alternative cognitive therapy for EI was developed to compensate for deficits resulting from structural lesions by strengthening undamaged pathways, which is achieved by superimposing volitional movement on muscles affected during an EI episode. Treatment of 17 patients showed significant reductions in EI severity and occurrence, and in contrast to drug treatments,the effect was sustained at 3- to 6-month follow-up.