NORMAL-PRESSURE HYDROCEPHALUS - PSYCHIATRIC FINDINGS BEFORE AND AFTERSHUNT OPERATION CLASSIFIED IN A NEW DIAGNOSTIC SYSTEM FOR ORGANIC PSYCHIATRY

23 patients with normal pressure hydrocephalus (NPH) underwent psychia tric examinations prior to and 80 days to 10 months after a ventriculo -peritoneal shunt operation. A global evaluation of the effect of the operation on the patients' mental symptoms indicated appreciable impro vement in 10 cases and slight improvement in a further 4. 8 patients w ere assessed as unchanged, and one as mentally deteriorated. The psych iatric analyses was based on a new diagnostic system created by two of che authors (G.L., H.M.). The patients manifested varying, often comp lex psychiatric symptom constellations with symptomatological componen ts from two or more organic mental disorders. Before the operation a m ild or a moderately severe somnolence-sopor-coma disorder (SSCD) was d iagnosed in 10 cases. After the operation all these patients became fr ee from symptoms of SSCD. This was the most unequivocal change in conn ection with the operation, and the elimination of all symptoms of SSCD was the single factor which most effectively contributed to the total therapeutical result in these patients. All 23 cases were considered to have symptoms of a more or less severe astheno-emotional disorder ( AED) preoperatively. The degree of severity of this disorder could not be determined with satisfactory certainty in some of the patients wit h complex symptoms. Amongst the 17 cases where the preoperative sympto matology allowed for a reasonably precise calculation of the degree of severity of AED, 6 were assessed as markedly improved after the opera tion and 10 as largely unchanged. In one patient, symptoms of the AED increased when the postoperative course was complicated by a subdural haematoma. Symptoms of an emotional-motivational blunting disorder (EM D) were diagnosed in 5 cases before the operation. After the operation 3 of these patients were symptom free in this respect while 2 were un changed. Slight or moderately severe symptoms of Korsakoff's amnestic disorder (KAD) were before the operation found in 7 cases: at the post operative examination 6 of these cases were improved, of which 4 were free from such symptoms; one was unchanged. According to our experienc e, confident prognoses concerning the effect of the shunt operation on symptoms of SSCD can be made preoperatively, while, for a particular patient, the therapeutic effect on AED, EMD and KAD is often difficult , or sometimes impossible, to foresee. This article contains three cas e reports which represent different forms and courses of the mental sy mptom patterns.