Subject(s)
Aging/psychology , Child Development , Emotions , Music/psychology , Adult , Child , Child, Preschool , Humans , Time Perception/physiologyABSTRACT
The objective of the study is to evaluate if the rupture of an aneurysm located on the middle cerebral artery (MCA) results in disorders of music recognition. To this aim, 20 patients having undergone brain surgery for the clipping of a unilateral left (LBS), right (RBS) or bilateral (BBS) aneurysm(s) of the MCA and 20 neurologically intact control subjects (NC) were evaluated with a series of tests assessing most of the abilities involved in music recognition. In general, the study shows that a ruptured aneurysm on the MCA that is repaired by brain surgery is very likely to produce deficits in the auditory processing of music. The incidence of such a deficit was not only very high but also selective. The results show that the LBS group was more impaired than the NC group in all three tasks involving musical long-term memory. The study also uncovered two new cases of apperceptive agnosia for music. These two patients (N.R. and R.C.) were diagnosed as such because both exhibit a clear deficit in each of the three music memory tasks and both are impaired in all discrimination tests involving musical perception. Interestingly, the lesions overlap in the right superior temporal lobe and in the right insula, making the two new cases very similar to an earlier case report. Altogether, the results are also consistent with the view that apperceptive agnosia results from damage to right hemispheric structures while associative agnosia results from damage to the left hemisphere.
Subject(s)
Agnosia/etiology , Infarction, Middle Cerebral Artery/complications , Intracranial Aneurysm/complications , Music/psychology , Adult , Agnosia/pathology , Agnosia/physiopathology , Auditory Cortex/pathology , Auditory Cortex/physiopathology , Auditory Perception/physiology , Female , Functional Laterality/physiology , Humans , Infarction, Middle Cerebral Artery/pathology , Infarction, Middle Cerebral Artery/surgery , Intracranial Aneurysm/pathology , Intracranial Aneurysm/surgery , Male , Middle Aged , Neuropsychological Tests , Postoperative Complications , Surgical Instruments/adverse effectsABSTRACT
Many mammalian tissues contain cardiac glycoside-like steroids that inhibit the sodium pump. A ouabain-like compound has been described in the human circulation and suggested to be ouabain or a closely related isomer. Ouabain is a highly hydroxylated compound and one of the most potent inhibitors of the sodium pump. Trialkylsilyl derivatization of ouabain has been carried out to determine reagent selectivity among the eight hydroxy groups as a prelude to the synthesis of regiospecific isomers. Mono-, di-, tri-, and hexa-trialkylsilyl derivatives have been prepared with substitution at the 19-, the 3',19-, the 1,3',19-, and the 1,2',3',4',11, 19-positions, respectively. Mass spectrometry and NMR confirmed the substitutions. Selective protection of the hydroxy groups allows selective oxidation of the unprotected steroid ring alcohols without oxidation of the 2'- and 4'-rhamnoside alcohols. Pyridinium dichromate oxidation of the di-trialkylsilyl and tri-trialkylsilyl derivatives gave the 1,11-diketone and the 11-ketone analogues, respectively. These regioselective reactions open a route to the synthesis of a series of closely related isomers of ouabain and other derivatives that may have useful structure-activity relationships and utility in the elucidation of the biosynthesis of ouabain-like compounds.
