Personality Change Due to a General Medical Condition

Personality Change Due to a General Medical Condition

Definition

The personality of an adult represents a coalescence of various personality traits present in childhood and adolescence, and is generally quite enduring and resistant to change. Thus, the ap-pearance of a significant change in an adult’s personality is an ominous clinical sign and indicates the presence of intracranial pathology. Patients themselves may not be aware of the change, however to others, who have known the patient over time, the change is often quite obvious: such observers often note that the patient is “not himself” anymore.

In most cases, the change is nonspecific in nature: there may be either a gross exaggeration of hitherto minor aspects of the patient’s personality or the appearance of a personality trait quite uncharacteristic for the patient. Traits commonly seen in a personality change, as noted in DSM-IV-TR, include lability, disinhibition, aggressiveness, apathy, or suspiciousness.

In addition to these nonspecific changes, there are two specific syndromes which, though not listed in DSM-IV-TR, are well-described in the literature, namely, the frontal lobe syn-drome and the interictal personality syndrome (also known as the “Geschwind syndrome”).

The frontal lobe syndrome is characterized by a variable mixture of disinhibition, affective changes, perseveration and abulia. Disinhibition manifests with an overall coarsening of be-havior. Attention to manners and social nuances is lost: patients may eat with gluttony, make coarse and crude jokes, and may engage in unwelcome and inappropriate sexual behavior, perhaps by propositioning much younger individuals or masturbating in public. Affective changes tend toward a silly, noninfectious euphoria; depression, however, may also be seen. Perseveration presents with a tendency to persist in whatever task is currently at hand, and patients may repeatedly button and unbutton cloth-ing, open and close a drawer or ask the same question again and again. Abulia is characterized by an absence of desires, urges or interests, and such patients, being undisturbed by such phenom-ena, may be content to sit placidly for indefinite periods of time. Importantly, such abulic patients are not depressed, nor are they incapable of activity: indeed, with active supervision they may be able to complete tasks; however, once supervision stops, so too do the patients, as they lapse back into quietude.

The interictal personality syndrome, a controversial entity (Bear et al., 1982; Rodin and Schmaltz, 1984) is said to occur as a complication of longstanding uncontrolled epilepsy, with repeated grand mal or complex partial seizures. The cardi-nal characteristic of this syndrome is what is known as “viscos-ity”, or, somewhat more colloquially, “stickiness”. Here, patients seem unable to let go or diverge from the current emotion or train of thought: existing affects persist long after the situation which occasioned them, and a given train of thought tends to extend itself indefinitely into a long-winded and verbose circum-stantiality or tangentiality. This viscosity of thought may also appear in written expression as patients display “hypergraphia”, producing long and rambling letters or diaries. The inability to “let go” may even extend to such simple acts as shaking hands, such that others may literally have to extract their hand to end the handshake. The content of the patient’s viscous speech and writing generally also changes, and tends toward mystical or abstruse philosophical speculations. Finally, there is also a tendency to hyposexuality, with an overall decrease in libido (Blumer, 1970).

Etiology and Pathophysiology

A personality change is not uncommonly seen as the prodrome to schizophrenia, however in such cases the eventual appearance of the typical psychosis will indicate the correct diagnosis.

Personality change of the nonspecific or of the frontal lobe type, as noted in Table 33.9, may occur secondary to precipi-tants (e.g., closed head injury), secondary to cerebral tumors (especially those of the frontal or temporal lobes) or as part of certain neurodegenerative or dementing disorders. Finally, there is a group of miscellaneous causes. In Table 33.9, those dis-orders or diseases which are particularly prone to cause a person-ality change of the frontal lobe type are indicated by an asterisk. The interictal personality syndrome occurs only in the setting of chronic repeated grand mal or complex partial seizures, and may represent microanatomic changes in the limbic system which have been “kindled” by the repeated seizures (Adamec and Stark-Adamec,1983;Bear,1979)

In the case of personality change occurring secondary to precipitants, the etiology is fairly obvious; an exception might be cerebral infarction, but here the acute onset and the presence of “neighborhood” symptoms are suggestive. In ad-dition to infarction of the frontal lobe, personality change has also been noted with infarction of the caudate nucleus and of the thalamus.

In the case of personality change occurring secondary to precipitants, the etiology is fairly obvious; an exception might be cerebral infarction, but here the acute onset and the presence of “neighborhood” symptoms are suggestive. In ad-dition to infarction of the frontal lobe, personality change has also been noted with infarction of the caudate nucleus and of the thalamus.

Personality change occurring secondary to cerebral tumors may not be accompanied by any distinctive features, and indeed a personality change may be the only clinical evidence of a tumor for a prolonged period of time.

Personality change occurring as part of certain neuro-degenerative or dementing disorders deserves special men-tion, for in many instances the underlying disorder may present with a personality change; this is particularly the case with Pick’s disease, fronto-temporal dementia and Alzheimer’s disease. The inclusion of amyotrophic lateral sclerosis here may be surpris-ing to some, but it is very clear that, albeit in a small minority cerebral symptoms may not only dominate the early course of ALS, but may even constitute the presentation of the disease. In the case of the other neurodegenerative disorders (i.e., progres-sive supranuclear palsy, cortico–basal ganglionic degeneration, multiple system atrophy, Huntington’s disease and Wilson’s dis-ease) a personality change, if present, is typically accompanied by abnormal involuntary movements of one sort or other, such as parkinsonism, ataxia or chorea. The lacunar syndrome, oc-curring secondary to multiple lacunar infarctions affecting the thalamus, internal capsule or basal ganglia, deserves special mention as it very commonly causes a personality change of the frontal lobe type by interrupting the connections between the thalamus or basal ganglia and the frontal lobe. Normal pres-sure hydrocephalus is an important diagnosis to keep in mind, as the condition is treatable: other suggestive symptoms include a broad-based shuffling gait and urinary urgency or incontinence. AIDS should be suspected whenever a personality change is accompanied by clinical phenomena suggestive of immunode-ficiency, such as thrush. Neurosyphilis may present with a per-sonality change characterized by slovenliness and disinhibition. Creutzfeldt–Jakob disease may also present with a personality change, and this appears particularly likely with the “new vari-ant” type: the eventual appearance of myoclonus suggests the correct diagnosis.

The miscellaneous causes represent the diagnostic “ze-bras” in the differential for personality change. Of them two de-serve comment, given their treatability: granulomatous angiitis is suggested by prominent headache, and vitamin B₁₂ deficiency by the presence of macrocytosis or a sensory polyneuropathy.

Assessment and Differential Diagnosis

Personality change must be clearly distinguished from a per-sonality disorder. The personality disorders (e.g., antisocial personality disorder, borderline personality disorder), all dis-cussed elsewhere in this book, do not represent a change in the patient’s personality but rather have been present in a lifelong fashion. In gathering a history on a patient with a personal-ity change, one finds a more or less distinct time when the “change” occurred; by contrast, in evaluating a patient with a personality disorder, one can trace the personality traits in question in a more or less seamless fashion back into adoles-cence, or earlier.

The frontal lobe syndrome, at times, may present further diagnostic questions, raising the possibility of either mania, when euphoria is prominent, or depression, when abulia is at the forefront. Mania is distinguished by the quality of the euphoria, which tends to be full and infectious in contrast with the silly, shallow and noninfectious euphoria of the frontal lobe syndrome. Depression may be distinguished by the quality of the patients’ experience: depressed patients definitely feel something, whether it be a depressed mood or simply a weighty sense of oppression. By contrast, the patient with abulia generally feels nothing: the “mental horizon” is clear and undisturbed by any dysphoria or unpleasantness.

MRI scanning is diagnostic in most cases: where this is uninformative, further testing is dictated by one’s clinical suspi-cions (e.g., HIV testing).

The interictal personality syndrome must be distin-guished from a personality change occurring secondary to a slowly growing tumor of the temporal lobe. In some cases, very small tumors, which may escape detection by routine MRI scanning, may cause epilepsy, and then, with continued growth, also cause a personality change. Thus, in the case of a patient with epilepsy who develops a personality change, the diagnosis of the interictal personality syndrome should not be made until a tumor has been ruled out by repeat MRI scanning.

Epidemiology and Comorbidity

Personality change is common, and is seen with especial fre-quency after closed head injury and as a prodrome to the de-mentia occurring with such neurodegenerative disorders as Pick’s disease, fronto-temporal dementia and Alzheimer’s disease.

Course

This is determined by the underlying cause; in the case of the interictal personality syndrome it appears that symptoms persist even if seizure control is obtained.

Treatment

Treatment, if possible, is directed at the underlying cause. Mood stabilizers (i.e., lithium, carbamazepine or divalproex) may be helpful for lability, impulsivity and irritability; propranoalol, in high dose, may also have some effect on irritability. Neurolep-tics (e.g., olanzapine, risperidone, haloperidol) may be helpful when suspiciousness or disinhibition are prominent. Antide-pressants (e.g., an SSRI) may relieve depressive symptoms. Regardless of which agent is chosen, it is prudent, given the general medical condition of many of these patients, to “start low and go slow”. In many cases, some degree of supervision will be required.