Behavioral Symptoms of the bvFTD Criteria of FTDC
Behavioral symptoms may be more severe in early onset than in late-onset bvFTD .
Early Behavioral Disinhibition, Loss of Self-Control
Socially inappropriate behaviors are particularly disturbing. Some are linked to impulsiveness and impaired social cognition (see below). Examples encountered in bvFTD are verbal or physical aggression, with the unusual use of rude words and swearing, criminal behavior (such as theft or shoplifting), public urination, and inappropriate sexual behaviors.
Aggression, impulsiveness, and lack of restraint can prevent carers from describing the real extent of the behavioral disturbances in the patient’s presence for fear of reprisals.
Inappropriate sexual behaviors are not specific to one cause of dementia  but often present in FTD . They can be seen at all stages irrespective of age, age at onset, gender, and educational level . They include excessive sexual comments, hugging/kissing/preoccupation with sex, masturbation in public, sexual hallucinations, addiction to Internet pornography, delusions of spousal infidelity, attempting to seduce/chasing people for sexual purposes, disrobing in public, and changes in sexual preference (paraphilic-related disorder). Some behaviors may be inappropriate only because they are performed publicly and may result from compulsive dis- inhibition rather than an increase in libido [29 ] . Paradoxically, in a systematic assessment of changes in sexual behavior in bvFTD, SD, and AD, bvFTD patients showed prominent hyposexual behaviors, including decreased affection, initiation, and response to advances by partners and decreased frequency of sexual relations, as compared to AD and SD patients. Notably, aberrant or unusual sexual behaviors were reported in a minority of bvFTD and SD patients and occurred in patients who also showed hyposexual behavior toward their partner .
Changes in sexual behavior are due to hormonal changes, disruption of interconnected brain structures (hypothalamus, amygdaloid nuclei, inferior frontal cortex, and medial striatal/septal region), or both . Sexual disinhibition could also be induced by blockade of either 5-HT2 receptor (selective serotonin reuptake inhibitors may suppress sexual drive), alpha-2 adrenergic receptor, or both . Medical care providers need to be trained to discuss these potential issues with patients and carers and to provide solutions to cope with these difficulties . Inappropriate sexual behaviors in the context of dementia are covered in another chapter of this book.
Loss of manners or decorum includes behaviors that violate social graces such as inappropriate laughter, cursing or loudness, offensive jokes or opinions, failing to wait in the line, and impolite physical behaviors (eating with mouth open, or putting a finger up the nose, flatulence, scratching private parts, picking teeth, belching, or spitting, etc.) . Milder symptoms are loss of respect for interpersonal space or propensity to continue talking despite others’ attempts to end a conversation.
]n this category the FTDC criteria for bvFTD criteria also included physical neglect, poor hygiene or grooming, and wearing the same, stained or inappropriate, clothing.
Impulsive rash or careless actions include dangerous driving, new-onset gambling, stealing (usually food or “shiny” objects), buying or selling objects without regard for consequences, or indiscriminate sharing of personal information .
Criminal violations can go from petty theft or running stop signs and traffic lights to child molestation, including pedophilic behavior. Patients with early FTD who commit criminal violations present a challenge to the criminal justice system since they have clear consciousness and normal global cognition, and one has to consider alterations in moral cognition before ascribing criminal responsibility . An important finding is that these patients are aware of the social rules, but their moral reasoning is defective, and they have difficulties in detecting violations of these rules. They understand the nature or their acts and the potential consequences, but do not feel concerned enough to be deterred. Criminal behavior in FTD may involve a unique combination of lesions. Alterations in the ventromedial prefrontal cortex may alter moral feelings, lesions in the right anterior temporal cortex may induce loss of emotional empathy, and orbitofrontal changes can cause disinhibited, compulsive behavior .
The patients no longer give the reassuring facial signals that there is social interaction. Neither do they show any feeling. They can appear hostile and can induce unease in others .
Antisocial acts, sometimes called “sociopathic,” are frequent in FTD, including stealing, hit and run accidents, physical assault, indecent exposure, public urination, inappropriate sexual behaviors, shoplifting, eating food in grocery store stalls, breaking and entering into other’s homes, driving violations, nonpayment of bills, and acts of violence. All these may be linked to ventromedial and orbitofrontal lesions of the frontal lobes. FTD patients may know right from wrong and understand the nature of their acts clearly enough so that they could be held legally culpable . These behaviors result from a combination of diminished emotional concern for the consequences of their acts and disinhibition consequent to right frontotemporal dysfunction. In many jurisdictions, FTD patients committing sociopathic acts would not pass legal criteria for “not guilty by reason of insanity” .
Lastly educational level shows an influence on disinhibition . Primarily studied in AD, the cognitive reserve hypothesis states that reserve mechanisms provided by high education and adult occupation could work against pathological process . Likewise, in FTD, patients with a higher reserve seem to require a more severe extent of neuropathology to develop behavioral disinhibition and loss of selfcontrol. The term “behavioral reserve” has been proposed to designate the putative protection provided by education .