Frontotemporal Dementia Presenting with Pathological Gambling

SIR: Pathological gambling (PG) is an impulse control disorder, characterized by a failure to resist the impulse to gamble at the risk of severe personal, family, or vocational consequences.¹ Similarities in decision-making behavior between PG patients and patients with prefrontal cortex lesions have recently suggested a possible implication of these areas in the pathophysiology of gambling.²

Frontotemporal dementia (FTD), is a progressive dementing condition characterized by selective degeneration of the frontal and anterior temporal lobes that causes a profound alteration in character and social conduct, in the context of relative preservation of perception, spatial skills, praxis, and memory.³

Here, we present a patient with FTD whose first symptom was PG. This association has apparently never been reported.

The patient is a 49-year-old male that had an unremarkable medical history since June 1999 when he started gambling with bingo and national lotto. Although gambling left him with significant debts and serious marital discord, he could not stop. Months later, familiars noted a progressive decline in his social conduct, disinhibition, and distractibility, while his PG slowly came to an end. In January 2001, the patient was referred to our Clinic. The neurological examination was unremarkable, except for bilateral grasp reflex. Neuropsychological testing showed a significant impairment on frontal lobe tests, and brain magnetic resonance imaging (MRI) showed predominant frontal and temporal atrophy. A diagnosis of FTD was then made, according to the current diagnostic criteria.³ Over the following months, behavioral changes progressively worsened toward severe frontal lobe dysfunction, with perseveration, echolalia, and poor emotional and cognitive awareness.

In the overactive disinhibited subtype of FTD, as in the case reported here, patients are disinhibited, fatuous, socially inappropriate, and lacking in concern, and pathological changes are relatively confined to orbitofrontal (OFC) and temporal neocortex.³ Interestingly, it has been recently shown that the OFC is implicated in decision-making processes and emotional-related learning and is involved in the representation of abstract rewards and punishments, such as receiving or losing money,⁴ a specific task that is disrupted in PG.

In our patient, the gambling behavior displayed in the initial phase of the disease was maladaptive, fulfilled the DSM-IV criteria, and was not referable to a coexisting maniac state or substance-abuse.¹ Furthermore, in the absence of a previous history of psychiatric disorders or gambling attitudes, it seemed related to the underlying degeneration of the frontal and temporal lobes, characteristic of the FTD.

This patient, then, with coexisting PG and FTD, lends additional support to the suggestion that an abnormal functioning of the OFC might be implicated in the pathophysiology of gambling behavior.²

Many dementing patients lose money control during the course of their disease, but PG has not been recorded as a prominent early feature in previous reports of FTD.³ This disorder, then, could be considered in the differential diagnosis of a new-onset gambling behavior in adults if PG is accompanied by changes of personality and other, more “typical” features of FTD.