Extensive and bilateral frontal lobe disease is accompanied by a quantitative reduction in all psychomotor activity. The number of movements, spoken words, and thoughts per unit of time diminish. Milder degrees of this state, associated with only a delay in responses, are called abulia as described earlier. The most severe degrees take the form of akinetic mutism wherein a nonparalyzed patient, alert and capable of movement and speech, lies or sits motionless and silent for days or weeks on end. It has been attributed to bilateral lesions in the ventromedial frontal regions or frontal-diencephalic connections (but focal lesions in the upper midbrain do the same). Laplane found that the lack of motivation of the patient with bifrontal lesions and bipallidal lesions to be the same, although one would expect the latter to manifest more as a bradykinesia than as a bradyphrenia (slowness of thinking).
The opposite state, in a sense, is a behavioral disinhibition that in extreme form becomes a hyperactivity syndrome, or “organic drivenness,” described by von Economo in children who had survived an attack of encephalitis lethargica. Disinhibition occurs largely with dorsolateral frontal lesions. In our patients, this syndrome has been produced most often by combined frontal and temporal lobe lesions, usually traumatic but also encephalitic, although exact clinicopathologic correlations could not be made. Such patients may also exhibit brief but intense involvement with some meaningless activity, such as sorting papers in an attic or hoarding objects or food. Possibly, compulsive behavior is related in some manner to this state and more particularly to lesions damaging the caudate-frontal connections. Combativeness and extreme insomnia or an otherwise disrupted sleep cycle are often part of the syndrome.
Pathological collecting behavior (hoarding) may be related to this type of drivenness and has been attributed to medial frontal lobe damage, including the cingulate gyri, by Anderson and colleagues based on a series of 13 patients. These patients, otherwise displaying mental clarity and despite negative personal and social consequences, collect massive amounts of useless items such as newspapers, junk mail, catalogs, food, clothing, and appliances, often encompassing several categories.
In addition to the disorders of initiative and spontaneity, frontal lobe lesions result in a number of other changes in personality and behavior. These, too, are easier to observe in the patient’s natural environment than to measure by psychologic tests. It has been difficult to find a term for all these personality changes. Some patients, particularly those with inferofrontal lesions, feel compelled to make silly jokes that are inappropriate to the situation, witzelsucht or moria; they are socially uninhibited and lack awareness of their behavior. The patient is no longer the sensitive, compassionate, effective human being that he once was, having lost his usual ways of reacting with affection and consideration to family and friends. In more advanced instances, there is an almost complete disregard for social conventions and an interest only in immediate personal gratification. The patient at the same time seems to lose an appreciation of the motivations and thought processes of other sapient persons (“theory of mind”); this results in the inability to incorporate these factors into his responses. These changes, observed characteristically in lobotomized patients, came to be recognized as too great a price to pay for the loss of anxiety, pain, depression, and “tortured self-concern,” hence the procedure became obsolete.