However, atypical antipsychotics are not free of the risk of development of NMS, and the explosive prevalence of SSRIs prescribed not only for depression but also for a number of psychiatric diagnoses such as anxiety, eating, impulse-control, and personality disorders may increase the incidence of ST. Therefore, these two pathological states still remain as major adverse effects of psychotropic drugs involving altered functioning of the central nervous system (CNS), to which all clinicians prescribing psychoactive drugs should pay attention. The popularity of SSRIs also increased the case reports of patients experiencing discontinuation syndrome, which sometimes includes CNS symptoms like anxiety and irritability. In this chapter, the author provides a comprehensive overview of the above- mentioned adverse effects affecting the CNS function associated with psychotropic pharmacotherapy. In addition, several other pathological conditions potentially causing encephalopathic symptoms in psychiatric patients treated with psychotropic drugs, e.g., hyponatremia, valproate-induced hyperammonemia, transient splenial lesion of the corpus callosum, and so on, are also described. Diagnosis
Blood tests, cerebrospinal fluid examination by lumbar puncture (also known as spinal tap), brain imaging studies, electroencephalography (EEG), neuropsychological testing and similar diagnostic studies may be used to differentiate the various causes of encephalopathy. Diagnosis is frequently clinical. That is, no set of tests give the diagnosis, but the entire presentation of the illness with nonspecific test results informs the experienced clinician of the diagnosis. Treatment
Treatment varies according to the type and severity of the encephalopathy. Anticonvulsants may be prescribed to reduce or halt any seizures. Changes to diet and nutritional supplements may help some people.
Toxic-metabolic encephalopathy: A catch-all for brain dysfunction caused by infection, organ failure, or intoxication. Transmissible spongiform encephalopathy: A collection of diseases all caused by prions, and characterized by "spongy" brain tissue (riddled with holes), impaired locomotion or coordination, and a 100% mortality rate. Includes bovine spongiform encephalopathy (mad cow disease), scrapie, and kuru among others. Neonatal encephalopathy (hypoxic-ischemic encephalopathy): An obstetric form, often occurring due to lack of oxygen in bloodflow to brain-tissue of the fetus during labour or delivery. Salmonella encephalopathy: A form of encephalopathy caused by food poisoning (especially out of peanuts and rotten meat) often resulting in permanent brain damage and nervous system disorders. Encephalomyopathy: A combination of encephalopathy and myopathy. Causes may include mitochondrial disease (particularly MELAS) or chronic hypophosphatemia, as may occur in cystinosis. Creutzfeldt–Jakob disease (CJD; transmissible spongiform encephalopathy). HIV encephalopathy (encephalopathy associated with HIV infection and AIDS, characterized by atrophy and ill-defined white matter hyperintensity). Sepsis-associated encephalopathy (this type can occur in the setting of apparent sepsis, trauma, severe burns, or trauma, even without clear identification of an infection). Epileptic encephalopathies:
Early infantile epileptic encephalopathy (acquired or congenital abnormal cortical development). Early myoclonic epileptic encephalopathy (possibly due to metabolic disorders). Gluten encephalopathy: Focal abnormalities of the white matter (generally area of low perfusion) are appreciated through magnetic resonance. Migraine is the most common symptom reported. Toxicity from chemotherapy
Chemotherapy medication, for example, fludarabine can cause a
permanent severe global encephalopathy.