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558 sEctiON iii Psychiatry ` Psychiatry—Pathology Psychiatry ` Psychiatry—Pathology

Amnesias
Retrograde amnesia Inability to remember things that occurred before a CNS insult.
Anterograde amnesia Inability to remember things that occurred after a CNS insult ( acquisition of new memory).
Korsakoff syndrome Amnesia (anterograde > retrograde) and disorientation caused by vitamin B deficiency. Associated
1
with disruption and destruction of the limbic system, especially mammillary bodies and
anterior thalamus. Seen in alcoholics as a late neuropsychiatric manifestation of Wernicke
encephalopathy. Confabulations are characteristic.

Dissociative disorders
Depersonalization/ Persistent feelings of detachment or estrangement from one’s own body, thoughts, perceptions,
derealization and actions (depersonalization) or one’s environment (derealization). Intact reality testing (vs
disorder psychosis).
Dissociative amnesia Inability to recall important personal information, usually following severe trauma or stress.
May be accompanied by dissociative fugue (abrupt, unexpected travelling away from home).
Dissociative identity Formerly called multiple personality disorder. Presence of ≥ 2 distinct identities or personality
disorder states. More common in women. Associated with history of sexual abuse, PTSD, depression,
substance abuse, borderline personality, somatic symptom disorders.

Delirium “Waxing and waning” level of consciousness Delirium = changes in sensorium.
with acute onset,  attention span,  level Treatment: identification and management of
of arousal. Characterized by disorganized underlying condition. Orientation protocols
thinking, hallucinations (often visual), (eg, keeping a clock or calendar nearby),
misperceptions (eg, illusions), disturbance  sleep disturbances, and  cognitive
in sleep-wake cycle, cognitive dysfunction, stimulation to manage symptoms.
agitation. Reversible. Antipsychotics as needed. Avoid unnecessary
Usually 2° to other identifiable illness (eg, CNS restraints and drugs that may worsen delirium
disease, infection, trauma, substance abuse/ (eg, anticholinergics, benzodiazepines,
withdrawal, metabolic/electrolyte disturbances, opioids).
hemorrhage, urinary/fecal retention), or
medications (eg, anticholinergics), especially
in the elderly.
Most common presentation of altered mental
status in inpatient setting, especially in the
ICU or during prolonged hospital stays. EEG
may show diffuse background rhythm slowing.

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