4. 8 ORGANIC PERSONALITY DISORDER
A variety of neurological and other
general medical conditions, including CNS neoplasms, TBI, cerebrovascular
disease, Huntington’s disease, epilepsy, endocrine conditions (e.g.,
hypothyroidism, hypo- and hyperadrenocorticism), and autoimmune conditions
(e.g., systemic lupus erythematosus), may cause personality changes (American
Psychiatric Association,
2000).
On the basis of the predominant
symptom presentation, DSM – IV classifies the personality changes into
labile, disinhibited, aggressive, apathetic, paranoid, other, combined and
unspecified subtypes. The clinical presentation in a given individual may
depend on the nature and localization of the pathologic process. Diseases
that preferentially affect frontal lobes or subcortical structures are
more likely to manifest with prominent personality change. Duffy and
Campbell (2001) identify three distinct prefrontal syndromes –
dysexecutive type, disinhibited type, and apathetic type. The dysexecutive
type involves the dorsal convexity system; and manifests with diminished
judgment, planning, insight and temporal organization; cognitive
impersistence, motor programming deficits, and diminished self care. The
disinhibited type involves the orbitofrontal system, and presents with
stimulus driven behavior, diminished social insight, distractibility and
emotional lability. The apathetic type is due to lesions in the mesial
frontal system, and is characterized by diminished spontaneity, verbal
output and motor behavior; urinary incontinence, lower extremity weakness
and sensory loss; and increased response latency. In clinical practice,
however, the lesions are seldom confined to any of these systems, and
patients are likely to manifest more than one of these symptom clusters.
Right hemisphere strokes have been shown to evoke personality changes in
association with unilateral spatial neglect, anosognosia, motor
impersistence, and other neurological deficits (American Psychiatric Association, 2000). Patients with
left hemisphere lesions may become paranoid (Benson, 1973), while injury
to the right hemisphere occurring early in life may lead to a personality
pattern characterized by shyness, depression, isolation and schizoid
behaviour (Eslinger and Geder, 2000).
The preliminary management of organic
personality disorders is directed at discovering and treating the
underlying etiology. Symptomatic treatments as a group have been only
marginally effective. Treatment approaches that have met with some success
include psychostimulants for attentional deficits (O’Shanick and O’Shanick,
1994); antipsychotics, benzodiazepines, buspirone, carbamazepine,
trazodone, propranolol, valproate, and lithium for disinhibited behaviour
(Silver and Yudofsky, 1994); and psychostimulants and dopaminergic agents
for apathy (Stewart et al., 1990). Pharmacotherapy should be combined with
education, family therapy, and individual therapy as appropriate for the
underlying condition (Lewis et al., 1992). |
