Silvia Muggia

Persistent retrograde, amnesia following a minor trauma.

A 19-year-old man showed dense retrograde amnesia (RA) for autobiographical and public events covering his entire life, following a motor car accident that caused no apparent brain damage. His learning abilities remained excellent and permitted him to recover knowledge of the past, based on information gathered from other people and the media, although he never reacquired the sense of personal experience. At the onset he also showed occasional gaps in his semantic memory, e.g., he failed to recognize a few objects and was unable to provide factual information about sports he had long been playing. Eventually, his amnesia was predominantly restricted to autobiographical events or facts. After 29 months the deficit has remained unchanged. CT, MRI and PET were negative. Psychogenic amnesia was considered, but eventually ruled out for want of any evidence pointing to emotional problems, stressful situations or secondary gains. We posit that for reasons unknown a mild trauma can cause functional inhibition of the access to the engrams that are already stored, leaving intact the ability to encode and retrieve new memories.

Cognitive modelling of face processing: evidence from Alzheimer patients

This is a prospective neuropsychological study on face processing in Alzheimers disease (AD). The aim was to assess the prevalence and the nature of face processing disorders in AD, and at investigating possible inter-test dissociations within the framework of currently used face processing models. A standardized four-test battery of unknown face discrimination and familiar face recognition was given to 30 mildly deteriorated patients with AD. Half of the patients performed below the cut-off in at least one of the tests. Deficits in familiar face recognition tests were more frequently observed than deficits in unknown face discrimination tests. There was no correlation between impairment of face processing and overall cognitive impairment or visual disorders. A multiple single case approach allowed us to elicit statistically warranted double dissociations between tasks assessing unknown face discrimination and tasks assessing familiar face recognition. Moreover, the ability to decide whether or not a stimulus is a face or a non-face has proven to be a non-mandatory step to further process the face stimuli. All together, these findings support the hypothesis that distinct pathways are involved in the processing of unknown and familiar faces, as posited by Bruce and Young [Br. J. Psychol. 77, 305-327, 1986].

Seeing Objects Smaller Than They are: Micropsia Following Right Temporo-Parietal Infarction

We report the case of an 84-year-old lady who, after a right temporo-parietal infarction, complained of seeing things smaller than she expected. She also related that straight lines appeared distorted and described seeing colours as if they were a badly mixed assemblage of hues. Her visual field was normal except for a transient left field extinction. No spatial neglect emerged. The patients micropsia remained unchanged during the course of the six month follow-up.

Fronto-Temporal Dementia and Motor Neuron Disease : a neuropsychological study

The neuropsychological follow‐up study of a 58‐year‐old man suffering from Motor Neuron Disease (ALS/MND) and Fronto‐Temporal Dementia (FTD) is reported. Neuromuscular signs first appeared at the age of 51 and slowly progressed to late bulbar involvement; behavioural symptoms of the frontal type first appeared around age 53; lastly, several neuropsychological symptoms suggestive of worsening temporal involvement supervened at age 57. Our patient died at 59 of respiratory failure with the classic clinical and neuroradiological picture of FTD. A short discussion addresses the controversial issue of the coupling of ALS/MND with Dementia and its possible interpretation as the expression of a chance association of relatively common diseases, versus that of a single multifaceted disease. The role of a detailed neuropsychological assessment is highlighted, within the context of increasingly specific diagnostic criteria for FTD.

Confabulation: Dissociation between everyday life and neuropsychological performance

Abstract The clinical and neuropsychological features of a patient, MB, suffering from diffuse meningo-encephalitic carcinomatosis are reported. MB showed a severe global amnesia and flourishing confabulation, preserving intelligence and lateralized functions. Confabulation emerged in informal conversation, without direct relation between amnesic gaps and confabulating behaviour, while it was almost absent from testing performance. Following the assumption of a continuum linking the classical ‘provoked’ to ‘spontaneous’ confabulation, we aim to discuss the role of amnesia and control function. Finally, we stress the dissoclation between the presence of confabulation in everyday life as opposed to its almost complete absence in a testing context.

Degenerative Dementia of the Frontal Type

The retrospective neurological, neuroradiological and neuropsychological observation of 9 cases of dementia with frontal symptoms is reported. Aim of this paper is to contribute to the clinical corpus of data related to the frontal features of the frontotemporal dementia (FTD) syndrome, so as to support clinicians’ awareness and widen the information available for the diagnostic approach to the dementias. FTD is a clinical diagnosis which does not imply a single underlying pathology, since more than one condition can induce the syndrome. Inertia and behavioural symptoms were the traits characterizing both the onset and the progression of the disease in our patients. Progression brought to the surface behavioural and neuropsychological patterns generically traced back to frontal dysfunction. Social inadequacy was the most salient trait. From a clinical point of view frontal dementias may be regarded as a conceptually different type of dementia with respect to Alzheimer’s disease, i.e., a ‘behavioural’ as opposed to a ‘cognitive’ progressive disorder.Renal blood flow (RBF) autoregulation reappears in postischemic rat kidneys during serotonin (5-HT2) antagonism. The aim of the present study was to analyze whether 5-HT2 antagonism can ameliorate impaired RBF autoregulation in rats treated with 20 mg/kg per d cyclosporin A during 10 d. Autoregulation of RBF was assessed during stepwise lowering of renal perfusion pressure from 110 to 70 mmHg by gradual compression of the aorta. Autoregulation was lost in the cyclosporin A-treated rats. During administration of the 5-HT2 antagonist ritanserin (0.6 mg/kg intravenous bolus, followed by 1.2 mg/kg per h intravenous infusion during 1 h), autoregulation acutely reappeared. Intrarenal bolus injections of a selective 5-HT2-agonist, 2,5 dimethoxy-4-iodoamphetamine hydrochloride, elicited a significantly stronger renal vasocontraction in cyclosporin A-treated rats than in control rats. This finding was also observed with serotonin after nitric oxide-synthase blockade. These results (1) show the importance of 5-HT2-receptor-mediated vasoconstriction in the suppression of vasodilatory autoregulation of RBF in experimental cyclosporin A-induced renal dysfunction and (2) demonstrate that the complete loss of RBF autoregulation is not due to damage of the vascular smooth muscle cells.