Evoked potentials and cerebral blood flow in solvent induced psycho-organic syndrome.

Epidemiological studies have provided evidence that neuropsychiatric symptoms are induced by long term exposure to solvents; individual diagnosis with psychometric tests, however, is not always possible (for example, when the patient has linguistic difficulties). Therefore evoked potentials and cerebral blood flow were studied in 50 patients occupationally exposed to solvents who were referred to our department and for whom a solvent induced psycho-organic syndrome was suspected. Degree of exposure was evaluated by its duration (mean 13.9, range 1 to 37 years) and its intensity (from an interview). At the group level, P22 and N35 latencies and amplitude N20-P22 of somatosensory evoked potentials were higher in cases than in controls (p < 0.05), whereas there was no difference for brainstem and visual evoked potentials, nor for hemispheric cerebral blood flow (but a higher distribution in the left occipital region was seen in patients, p < 0.05). Some parameters were linked to degree of exposure (amplitude N20-P22 of somatosensory evoked potentials, interpeak latency I-V of brainstem evoked potentials, distribution of cerebral blood flow in the internal frontal left region). At the individual level, these examinations were not of diagnostic value because sensitivity was low.

[Glycerol monothioglycolate eczema in a hairdresser. Persistence of the allergen in the hair several weeks after the application of a permanent]. / Eczéma au monothioglycolate de glycérol chez une coiffeuse. Persistance de l'allergène dans les cheveux plusieurs semaines après l'application d'une permanente.

Glyceryl thioglycolate has been used for a pair of years in acid permanent wave solutions. It appears to be much more sensitizing than ammonium thioglycolate which is usually the main component of this kind of cosmetics. A case of allergic contact dermatitis due to glyceryl thioglycolate is reported. The patient was a 43-year old woman with an eczematous dermatitis of both hands. She was a hairdresser and eczematous eruptions were strictly work-related. She had no direct contact with most cosmetics and only used tools (scissors, clips, pins, rollers, combs...) and hair spray. Patch testing was however done with the standard patch-test screening tray and all the products used in the shop. The only positive reaction was due to a permanent wave solution containing only glyceryl thioglycolate and glycerol. Positive patch-test reactions were also obtained with hair treated with the permanent wave solution and cut immediately or several weeks after the application of the preparation. This observation shows that glyceryl thioglycolate may be responsible for allergic contact dermatitis in hairdressers; it emphasizes the long remanence of the allergen in the hair that makes its eviction specially difficult.