In addition, chemicals, such as lead, that could instigate<unk>  are sometimes found in everyday products such as prescription drugs, cleaning products, building materials, pesticides, air fresheners, and even perfumes. These harmful chemicals can be inhaled (in the case of air fresheners) or applied (in the case of perfumes). The substances diffuse into the brain rapidly, as they are lipophilic and readily transported across the blood–brain barrier. This is a result of increased membrane solubility and local blood flow, with central nervous system (CNS) solvent uptake being further increased with high levels of physical activity. When they are not detoxified immediately, the symptoms of<unk>  begin to emerge. However, in chronic situations, these effects may not become severe enough to be noticed until much later. Increased exposure time and increased concentration of the chemicals will worsen the effects of<unk> , due to the associated structural CNS damage and direct functional impairment consequences. Subacute<unk> es are challenging to identify due to their often insidious<unk> mpo of evolution, nonspecific manifestations, relative infrequency as individual entities, and frequent lack of specific diagnostic<unk> sting. Yet they are crucial to recognize in aggregate, subacute<unk> es are a common problem that can lead to severe, irreversible harm if not diagnosed and treated efficiently. This article reviews the clinically relevant aspects of some of the more important subacute<unk>  syndromes caused by inorganic<unk> s, carbon monoxide (CO), anti- biotics, antineoplastic agents, and psychiatric medications. All therapeutic interventions are double-edged swords with benefits and adverse effects, and pharmacotherapy is not an exception. Shortly after the introduction of conventional antipsychotic drugs into clinical practice, relatively rare but serious complications with hyperthermia, muscle rigidity, autonomic instability, and disturbed mental status were recognized to develop in some patients treated with antipsychotics. This type of encephalopathy induced by the use of antipsychotics was referred to as neuroleptic malignant syndrome (NMS), and almost all physicians prescribing antipsychotics are nowadays aware of this adverse phenomenon. Another well-known type of encephalopathy associated with psychotropic drug therapy is serotonin<unk> ity (ST) or serotonin syndrome (SS), which is characterized by autonomic and neuromuscular symptoms and altered mental status. In contrast with the idiosyncratic nature of NMS, ST is a spectrum pathophysiological state assumed to derive from excess serotonergic neural transmission caused by serotonin-related psychotropic agents. In these two decades, pharmacotherapy with psychotropic drugs for mentally ill patients has been dramatically changed, and classical prototypal antipsychotics and antidepressants have been replaced with atypical antipsychotics and selective serotonin reuptake inhibitors (SSRIs), respectively. These newly developed psychotropic drugs are generally safer and more tolerable than older drugs. 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 suffering from 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. Fume events on aircraft have been linked to cases of<unk> , for example in the case of JetBlue Captain Andrew Myers, who as a result of exposure needed a cane to walk, suffered from tremors and struggled to speak. In the following year, the Federal Aviation Administration revoked Myers' medical certificate; the workers compensation board agreed that Myers suffered brain damage as a result of the event.
Toxic encephalopathy
Glycine encephalopathy
Viral encephalitis
Wernicke encephalopathy
Ethylmalonic encephalopathy
Powassan encephalitis
Autoimmune encephalitis
Herpesviral encephalitis