A 72 year-old right handed woman had a right sided anterior choroidal artery infarction. She presented the triad of hemiplegia, hemianaesthesia, and homonymous hemianopsia, as well as complete non-determinant hemisphere syndrome that combined: disorientation for place and time, anosognosia, hemiasomatognosia, left spatial neglect, constructional apraxia and spatial fabulation concerning both the present time and the weeks that preceded the vascular event. Language and verbal memory were normal. Spatial memory could not be studied because of the severity of the neglect. The clinical course was poor: when tested one and a half year post-onset, the hemiplegia, the hemianaesthesia, and the hemianopsia as well as left spatial neglect remained severe. Vestibular caloric stimulation, carried out with left ear cold water irrigation, resulted in brief but clear-cut alleviation of the spatial neglect. An MRI with both axial and coronal slices showed a right-sided infarct affecting the whole posterior limb of the internal capsule including the genu, the posterior part of the globus pallidus, the anterior third of the cerebral peduncle and the amygdala but sparing the thalamus and the corona radiata. This crescent-shaped lesion transected entirely the thalamo-cortical connection fibers which resulted in a "thalamic exclusion". The measurement of brain glucose utilisation with (18F)-Fluoro-2-Deoxy-D-Glucose and positron emission tomography performed in the chronic phase (3 months post-onset) showed an exceptionally severe and widespread hypometabolism of the right hemisphere, relative to the left hemisphere, which correlated with both the unusual, severe and protracted non-dominant hemisphere syndrome. All the brain regions on the right side were hypometabolic relative to the left including the temporal region (mostly medial temporal), the left cerebellar lobe, the frontal lobe (mostly prefrontal region), the occipital region and the thalamus. The hypometabolism of the basal ganglia, the sensorimotor area and the parietal cortex was less severe. This most uncommon clinical-metabolic presentation presumably reflects a global thalamo-cortical disconnection inducing a diffuse dysfunction of the whole hemisphere.