[Semantic dementia, a many-worded disorder].
BACKGROUND
Semantic dementia is a progressive, relatively selective disorder affecting the semantic system with involvement of the verbal and non-verbal functions. The clinical picture is well characterised despite the confusion that may be generated by the different ways of classifying it. AIM. To determine the clinical, neurolinguistic, imaging and pathological features of this progressive language disorder.


METHODS
Evaluation of language reveals above all the existence of semantic paraphasias, disorders affecting the comprehension of isolated words and surface dyslexia. Flow of speech, complex syntactic comprehension and grammar are preserved. Both episodic and autobiographic memory are close to normality. Both the clinical signs and symptoms and imaging studies agree on the fact that the most heavily affected area is the anteroinferomedial region of the temporal lobe on a bilateral scale but with predominance of the left-hand side. Pathologically, in most cases positive intraneuronal ubiquitin inclusions are observed like those described in motor neuron diseases.


CONCLUSIONS
Semantic dementia constitutes a diagnosis challenge, mainly from the neuropsychological point of view. Further advances towards reaching a diagnosis would allow us to determine which area is mainly affected and, in the future, to find an effective treatment for this progressive, degenerative disorder.
O'Neill
S
S
Servicio de Neurología, Centro Neurológico-Hospital Francés, La Rioja 951, 1221 Buenos Aires, Argentina. santioneill@intramed.net
Andreotti
M
M
de Simone
V
V
D000368:Aged; D001039:Aphasia, Broca / Q000209:etiology; D001931:Brain Mapping; D003704:Dementia / Q000145:classification / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology / Q000523:psychology; D018450:Disease Progression; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D001523:Mental Disorders / Q000209:etiology; D008875:Middle Aged; D012660:Semantics; D013702:Temporal Lobe / Q000503:physiopathology; D015899:Tomography, Emission-Computed, Single-Photon; D014705:Verbal Behavior