The authors describe three pathological cases of akinetic mutism with, as a common basic lesion, bilateral infarction of the cingulate gyrus secondary to aneurysm of the anterior communicating artery (case n degrees 1), to a huge olfactory meningioma (case n degrees 2), both operated on, and to atheromatous occlusion of the anterior cerebral arterial system (case n degrees 3). These three cases enable a variety of "anterior and waking" akinetic mutism to be described which is unusual enough to be compared with other mesencephalic and diencephalic aspects of this syndrome. It is in fact an akinetic mutism characterized by: a certain dissociation in its non-response to various stimuli, a particularly marked appearance of wakefulness when day-time alertness is considered, conservation of the waking-sleeping rhythm, perception and reaction unpredictable and paradoxical in both degree and quality, complete absence of any spontaneous verbal communication in contrast to relative break-down of solicited communication which is infrequent, uncertain and unresponsive to the usual methods of stimulation, without any possibility of a code. In addition, there is a remarkable mimic and segmental general akinesia, resistant to the usual nociceptive stimuli, but sensitive to slight excitation of the manual and oral zones. Besides this special akinetic mutism, there are variously systematised signs, mostly asymmetrical, indicating lesion of the cortico-sub-cortical frontal structures bordering on the gyrus cinguli. This unusual behaviour pattern corresponds in these three cases to extensive anterior bilateral ischemic lesions of the cingulate gyrus regularly associated with bilateral infarctions confined to the medial aspect of F1 in the superficial territory of the two anterior cerebral arteries, to possible neurosurgical changes (ablation of the right frontal pole) and to compressive or ischaemic lesions of the gyrus rectus. These exclusively cortico-sub-cortical associated lesions are in contrast with the remarkably intact caudate nuclei, the pallidal, thalamic, hypothalamic and septal formations and the anterior pillars of the fornix. These findings compared with the results of experimental research carried out by M. Kennard, help, if help is needed, to resolve the apparent contradictions between the effects of therapeutic cingulectomies or cingulotomies and the scanty pathological data already available in cerebral vascular pathology.