Chronic solvent-induced encephalopathy

Chronic solvent induced encephalopathy (CSE) is a condition induced by long-term exposure to organic solvents, often but not always in the workplace, that lead to a wide variety of persisting sensorimotor polyneuropathies and neurobehavioral deficits even after solvent exposure has been removed. This syndrome can also be referred to as 'psycho-organic syndrome', 'organic solvent syndrome', 'chronic painter's syndrome', 'occupational solvent encephalopathy', 'solvent intoxication', 'toxic solvent syndrome', 'painters disease', 'psycho-organic syndrome', 'chronic toxic encephalopathy', and 'neurasthenic syndrome'. The multiple names of solvent induced syndromes combined with inconsistency in research methods makes referencing this disease difficult and its catalog of symptoms vague. Chronic solvent induced encephalopathy (CSE) is a condition induced by long-term exposure to organic solvents, often but not always in the workplace, that lead to a wide variety of persisting sensorimotor polyneuropathies and neurobehavioral deficits even after solvent exposure has been removed. This syndrome can also be referred to as 'psycho-organic syndrome', 'organic solvent syndrome', 'chronic painter's syndrome', 'occupational solvent encephalopathy', 'solvent intoxication', 'toxic solvent syndrome', 'painters disease', 'psycho-organic syndrome', 'chronic toxic encephalopathy', and 'neurasthenic syndrome'. The multiple names of solvent induced syndromes combined with inconsistency in research methods makes referencing this disease difficult and its catalog of symptoms vague. Two characteristic symptoms of CSE are deterioration of memory (particularly short-term memory), and attention impairments. There are, however, numerous other symptoms that accompany to varying degrees. Variability in the research methods studying CSE makes characterizing these symptoms difficult, and some may be questionable regarding whether they are actual symptoms of solvent-induced syndromes, simply due to how infrequently they appear. Characterizing of CSE symptoms is more difficult because CSE is currently poorly defined, and the mechanism behind it is not understood yet. Reported neurological symptoms include difficulty sleeping, decrease in intellectual capacity, dizziness, altered visual perceptive abilities, affected psychomotor skills, forgetfulness, and disorientation. The mechanism behind these symptoms beyond solvent molecules crossing the blood-brain barrier is currently unknown. Neurological signs include impaired vibratory sensation at extremities and an inability to maintain steady motion, a possible effect from psychomotor damage in the brain. Other symptoms that have been seen range from fatigue, decreased strength, and unusual gait. One study found that there was a correlation between decreased red blood cell count and level of solvent exposure, but not enough data has been found to support any blood tests to screen for CSE. A 1988 study indicated that some solvent-exposed workers suffered from loss of smell or damage to color vision; however this may or may not have been actually caused by exposure to organic solvents. There is other evidence for subtle impairment of color vision (especially titian or 'blue-yellow' losses), synergistic exacerbation of hearing loss, and loss of the sense of smell (anosmia). Psychological symptoms of CSE that have been reported include mood swings, increased irritability, depression, a lack of initiative, uncontrollable and intense displays of emotion such as spontaneous laughing or crying, and a severe lack of interest in sex. Some psychological symptoms are believed to be linked to frustration with other symptoms, neurological, or pathophysiological symptoms of CSE. A case study of a painter diagnosed with CSE reported that the patient frequently felt defensive, irritable, and depressed because of his memory deficiencies. Organic solvents that cause CSE are characterized as volatile, blood soluble, lipophilic compounds that are typically liquids at normal temperature. These can be compounds or mixtures used to extract, dissolve, or suspend non-water-soluble materials such as fats, oils, lipids, cellulose derivatives, waxes, plastics, and polymers. These solvents are often used industrially in the production of paints, glues, coatings, degreasing agents, dyes, polymers, pharmaceuticals, and printing inks. Exposure to solvents can occur by inhalation, ingestion, or direct absorption through the skin. Of the three, inhalation is the most common form of exposure, with the solvent able to rapidly pass through lung membranes and then into fatty tissue or cell membranes. Once in the bloodstream, organic solvents, due to their lipophilic properties, easily cross the blood-brain barrier. The mechanism of effect that these solvents have on the brain that cause CSE, however, is not yet fully understood. Some common organic solvents known to cause CSE include formaldehyde, acetates, and alcohols. Due to its non-specific nature, diagnosing CSE requires a multidisciplinary 'Solvent Team' typically consisting of a neurologist, occupational physician, occupational hygienist, neuropsychologist, and sometimes a psychiatrist or toxicologist. Together, the team of specialists assess the patient's history of exposure, symptoms, and course of symptom development relative to the amount and duration of exposure, presence of neurological signs, and any existing neuropsychological impairment.