El "efecto Tortoni" en la prosopagnosia / The "Tortoni effect" in prosopagnosia

Resumen La prosopagnosia es un tipo de agnosia visual caracterizada por la incapacidad de reconocer los rostros de las personas. Existen básicamente dos variantes, aperceptivas y asociativas. El "efecto Tortoni" es un fenómeno descripto por Bekinschtein y col. hace unos años en mozos de café en Buenos Aires, quienes utilizaban esta herramienta para recordar los pedidos de cada integrante de una mesa. Presentamos un caso de prosopagnosia asociada a lesión temporo-occipital bilateral secundaria a traumatismo encefalocra neano, manifestada en forma inicial por la falta de reconocimiento de rostros, con la utilización de una estra tegia asociativa similar a la descripta en el efecto "Tortoni" como compensación. Mujer de 62 años que sufrió un traumatismo encefalocraneano grave. Pocos meses después del evento, presentó dificultad para reconocer personas conocidas, hecho evidenciado por sus allegados cuando en una mesa los integrantes cambiaron su asiento, permanecieron callados por unos instantes, y posteriormente la paciente continuó nombrándolos por su ubicación previa. En la resonancia magnética de cerebro se objetivaron lesiones contusas de aspecto secuelar en región temporo-occipital bilateral. La prosopagnosia adquirida secundaria a lesiones focales en la región temporo-occipital generalmente bilateral, derecha, y raramente izquierda, es un cuadro poco frecuente. La es trategia utilizada en el "efecto Tortoni" fue en nuestra paciente una de las manifestaciones iniciales del cuadro. La realización de un test neuropsicológico ecológico que considere esta estrategia podría ser de utilidad en el rastreo y detección precoz de esta entidad.

Abstract Proposapnosia is a type of visual agnosia characterized by the inability to recognize people's faces. There are basically two variants, apperceptive and associative. The "Tortoni effect" is a phenomenon described by Bekinschtein et al a few years ago in waiters from Buenos Aires, who used this tool to remember the orders of each member of a table. We present a case of prosopagnosia associated with bilateral temporo-occipital injury secondary to head trauma, initially manifested by the lack of face recognition with the use of an associative strategy similar to that described in the "Tortoni effect" as compensation, in a 62-year-old female who suffered a severe head injury. A few months after this event, the patient had difficulty in recognizing familiar people, a fact evidenced by her relatives when at a restaurant table, they changed their seats, remained silent momentarily, and right after the patient kept naming them by their previous location. The magnetic resonance imaging of the brain revealed blunt sequelae lesions in the bilateral temporo-occipital region. Acquired prosopagnosia due to focal lesions in the temporo-occipital region, generally bilateral and right, and less frequently left, is a rare condition. The strategy used in the "Tortoni effect" was one of the initial manifestations of the condition in our patient. Carrying out an ecological neuropsychological test that considers this strategy could be useful in the screening and early detection of this entity.

Inverse Anton syndrome: A case report

@#This a case report on a rare case of denial of visual perception termed as inverse Anton syndrome. It is a rare extension of perception without awareness in which, specific brain lesions affected a patient’s visual abilities. A 66-year-old Malay gentleman presented with sudden onset of the painless bilateral total loss of vision with expressive aphasia for 2 days. His visual acuity was 6/12 in the right eye and 6/48 in the left eye. However, he was insistent that he could not see but did not request any form of assistance for his blindness. He also had neurological signs suggestive of parietal lobe syndrome. Brain imaging showed subacute left middle cerebral artery territorial infarct with no occipital lobe involvement. The denial of visual perception by this patient may be explained by a disconnection of parietal lobe attentional systems from visual perception

Demencia frontotemporal: variante temporal derecha, reporte de dos casos / Frontotemporal Dementia: Right Temporal Variant, report of 2 cases

La demencia frontotemporal derecha es una variante anatómica de la demencia frontotemporal. Se asocia con síntomas cognitivos y comportamentales característicos, entre los que se destacan: agnosia topográfica, desorientación espacial, prosopagnosia, conductas obsesivas, agresividad, impulsividad, desinhibición y pérdida de la empatía. Se reportan dos casos, que desde el punto de vista clínico e imaginológico, resultan ilustrativos de la variante derecha en la demencia frontotemporal.

Right temporal frontotemporal dementia is an anatomic variant of frontotemporal dementia. It is associated with some characteristic behavioral and cognitive symptoms: topographic agnosia, spatial disorientation, prosopagnosia, obsessive behaviors, aggressiveness, impulsiveness, disinhibition and lack of empathy. Here we report two clinical cases, that, from a clinical and radiologic point of view, illustrate the right variant of frontotemporal dementia.

Prosopagnosia congênita: relato de caso / Congenital prosopagnosia: a case report

Prosopagnosia is a visual agnosia characterized by an inability to recognize previously known human faces and to learn new faces. The aim of this study was to present a forty-six year-old woman with congenital prosopagnosia, and to discuss the neural bases of perception and recognition of faces. The patients had a lifetime impairment in recognizing faces of family members, close friends, and even her own face in photos. She also had impairment in recognizing animals such as discriminating between cats and dogs. The patients basic visual skills showed impairment in identifying and recognizing the animal form perception on the coding subtest of the WAIS-R, recognizing overlapping pictures (Luria), and in identifying silhouettes depicting animals and objects (VOSP). Unconventional tests using pictures evidenced impairment in her capacity to identify famous faces, facial emotions and animals. Her face perception abilities were preserved, but recognition could not take place. Therefore, it appears that the agnosia in this case best fits the group of categories termed associative.

Prosopagnosia é uma agnosia visual caracterizada por uma incapacidade de reconhecer faces humanas vistas anteriormente e aprender outras. O objetivo é apresentar uma mulher de 46 anos com prosopagnosia congênita e discutir as bases neurais da percepção e do reconhecimento de faces. Ela nos procurou referindo apresentar desde a infância problemas no reconhecimento de faces de membros da família, amigos próximos e mesmo para sua própria imagem numa fotografia. Também diz apresentar prejuízo no reconhecimento de animais, como discriminar cães de gatos. Apresentou dificuldades em identificar e reconhecer animais desenhados; reconhecer figuras sobrepostas (Luria), incorrendo em paragnosias visuais e identificar silhuetas de animais (VOSP). Em testes não convencionais, usando figuras, evidenciou diminuição da capacidade em identificar faces famosas, expressões faciais e animais, mas não em estimar o sexo e a idade das pessoas. Concluindo, suas habilidades perceptuais para face estão preservadas, mas há um déficit de reconhecimento. Tudo indica que sua agnosia pertence ao grupo das associativas.

Face perception in its neurobiological and social context

Significant advances in the understanding of processes involved in face perception have been achieved. This study aims to review the literature of face perception in neurobiological and social contexts. The review focused on the mechanisms of mediation of face perception by neural substrates, and discussed some of the social signals provided by faces. We showed that psychological, neurophysiological and neuroimaging studies have demonstrated that a dedicated neural system for face perception exists in primates, which includes the fusiform face area (FFA), anterior superior temporal sulcus (STS) and anterior inferior temporal gyrus (ITG). But it remains to be understood how the integration of face perception occurs in the neurobiological context and in the social context.