We report on the clinical and radiological features in 16 adult patients who suffered a traumatic brain injury and subsequently developed pathological laughter and crying. Patients with pathological laughter and crying were identified from among 301 consecutive brain-injured admissions to a trauma centre and subsequently to a rehabilitation facility. Patients displaying pathological laughter and crying had a greater severity of injury than patients without the syndrome; they also had other associated neurological features compatible with pseudobulbar palsy. Pathological laughter alone, or combined with crying, was more frequent than crying alone. An attempt to correlate clinical features with focal lesions on neuroimaging studies yielded inconsistent results. The theoretical anatomical substrate for pathological laughter and crying in patients with traumatic brain injury is discussed.
Crying/physiology , Head Injuries, Closed/physiopathology , Laughter/physiology , Adolescent , Adult , Basal Ganglia/injuries , Basal Ganglia/physiopathology , Brain Damage, Chronic/physiopathology , Brain Damage, Chronic/rehabilitation , Brain Mapping , Cerebral Cortex/injuries , Cerebral Cortex/physiopathology , Dominance, Cerebral/physiology , Female , Head Injuries, Closed/rehabilitation , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Paralysis/physiopathology , Paralysis/rehabilitation , Tomography, X-Ray Computed
The freely diffusible gaseous compound nitric oxide (NO) has recently been discovered to be an important cellular messenger in many organ systems throughout the body. The importance of NO as an intermediary in cell communication in the brain is highlighted by the fact that the excitatory amino acid glutamate, the most abundant central neurotransmitter, is an initiator of the reaction that forms NO. In this article, background information about the discovery of NO, its biochemistry, and a brief summary of some of its peripheral and central actions are given to provide a complete picture of this remarkable novel second messenger. We also discuss how an improved understanding of NO pathway may lead to the identification of novel medications for the treatment of a number of neuropsychiatric conditions, including memory deficits, pain, drug addiction, seizures, bipolar disorder, psychosis, eating disorders, and the treatment of the sequelae of various brain injuries.
Memory Disorders/drug therapy , Mental Disorders/drug therapy , Nitric Oxide/pharmacology , Nitric Oxide/therapeutic use , Animals , Humans , Substance-Related Disorders/drug therapy
