Amnesia- a disturbance in or loss of memoryâ€”may be classified as partial or complete and as anterograde or retrograde. Anterograde amnesia denotes memory loss of events occurred after the onset of the causative trauma or disease; retrograde amnesia, memory loss of events that occurred before the onset. Depending on the cause, amnesia may arise suddenly or slowly and may be temporary or permanent.
Organic (or true) amnesia results from temporal lobe dysfunction, and it characteristically spares patches of memory. A common symptom in patients with seizures or head trauma, organic amnesia can also be an early indicator of Alzheimer’s disease. Hysterical amnesia has psychogenic origin and characteristically causes complete memory loss. Treatment induced amnesia is usually transient.
Medical causes of amnesia
Alzheimer’s disease: – Alzheimer’s disease usually begins with retrograde amnesia, which progresses slowly over many months or years to include anterograde amnesia, producing severe and permanent memory loss. Associated findings include agitation, inability to concentrate, disregard for personal hygiene, confusion, irritability, and emotional liability. Later signs include aphasia, dementia, incontinence, and muscle rigidity.
Cerebral hypoxia: –After recovery from hypoxia (brought on by such conditions as carbon monoxide poisoning or acute respiratory failure), the patient may experience total amnesia for the event, along with sensory disturbances, such as numbness and tingling.
Head trauma: – Depending on the trauma’s severity, amnesia may last for minutes, hours, or longer. Usually, the patient experiences brief retrograde and longer anterograde amnesia as well as persistent amnesia about the traumatic event. Severe head trauma can cause permanent amnesia or difficulty retaining recent memories. Related findings may include altered respiration and LOC (level of consciousness); headache; dizziness; confusion; visual disturbances, such as blurred or double vision; and motor and sensory disturbances, such as hemiparesis and paresthesia, on the side of the body opposite the injury.
Herpes simplex encephalitis: – Recovery from herpes simplex encephalitis commonly leaves the patient with severe and possibly permanent amnesia. Associated findings include signs and symptoms of meningeal irritation, such as headache, fever, and altered LOC, along with seizures and various motor and sensory disturbances (such as paresis, numbness, and tingling).
Hysteria: – Hysterical amnesia, a complete and long-lasting memory loss, begins and ends abruptly and is typically accompanied by confusion.
Seizures: – In temporal lobe seizures, amnesia occurs suddenly and lasts for several seconds to minutes. The patient may recall an aura or nothing at all. An irritable focus on the left side of the brain primarily causes amnesia for verbal memories, whereas an irritable focus on the right side of the brain causes graphic and nonverbal amnesia. Associated signs and symptoms may include decreased LOC during the seizure, confusion, abnormal mouth movements, and visual, olfactory, and auditory hallucinations.
Wernicke-Korsakoff syndrome: – Retrograde and anterograde amnesia can become permanent without treatment in this syndrome. Accompanying signs and symptoms include apathy, an inability to concentrate or to put events into sequence, and confabulation to fill memory gaps. The syndrome may also cause diplopia, decreased LOC, headache, ataxia, and symptoms of peripheral neuropathy, such as numbness and tingling.
Other causes of amnesia:-
Anterograde amnesia can be precipitated by general anesthetics, especially fentanyl, halothane, and isoflurane; barbiturates, most commonly pentobarbital and thiopental; and certain benzodiazepines, especially triazolam.
The sudden onset of retrograde or anterograde amnesia occurs with electroconvulsive therapy. Typically, the amnesia lasts for several minutes to several hours, but severe, prolonged amnesia occurs with treatments given frequently over a prolonged period.
Temporal lobe surgery: – Usually performed on only one lobe, this surgery causes brief, slight amnesia. Removal of both lobes results in permanent amnesia.
Symptoms and Diagnostic Path of amnesia
Retrograde amnesia refers to the loss of memories of the past, while anterograde amnesia refers to amnesia that occurs after the precipitating event that led to the amnesia. Dissociative amnesia, formerly known as psychogenic amnesia, is a form of amnesia that occurs directly after the distressing event, and which includes a loss of personal identity. It is not, however, comparable to the repressed memories of individuals who have experienced CHILD PHYSICAL ABUSE OR CHILD SEXUAL ABUSE. In general, dissociative amnesia resolves itself within several weeks. Other forms of amnesia may be more long lasting. Amnesia is diagnosed by first obtaining a detailed medical history, a physical examination including blood tests, and MRI if the brain has been damaged. Detailed interviews with the patient and family members are also necessary. For the diagnosis of dissociative amnesia there are several questionnaires such as the DISSOCIATIVE EXPERIENCE SCALE and the STRUCTURED CLINICAL INTERVIEW (SCID-D).
Treatment of amnesia
Psychotherapy: – Successful psychotherapy for the patient with dissociative identity disorder requires the clinician to be comfortable with rage of psychotherapeutic interventions and be willing to actively work to structure the treatment. These modalities include psychoanalytic psychotherapy, cognitive therapy, behavioral therapy, hypnotherapy, and a familiarity with the psychotherapy and psychopharmacological management of the traumatized patient. Comfort with family treatment and systems theory is helpful in working with a patient who subjectively experiences himself or herself as a complex system of selves with alliances, family like relationships, and intergroup conflict. Grounding-in work with patients with somatoform disorders may also be helpful in sorting through the plethora of somatic symptoms with which these patients commonly present.
Cognitive Therapy: – Many cognitive distortions associated with dissociated identity disorder are only slowly responsive to cognitive therapy techniques, and successful cognitive interventions may lead to additional dysphoria. A subgroup of patients with dissociative identity disorder does not progress beyond a long term supportive treatment entirely directed towards stabilization of their multiple multiaxial difficulties. They require a long-term treatment focus on symptom containment and management of their overall life dysfunction, as would be the case with any other severely and persistently ill psychiatric patient.
Psychopharmacological Interventions:-Antidepressant medications are often important in the reduction of depression and stabilization of mood. A variety of PTSD symptoms, especially intrusive and hyper arousal symptoms, are partially medications responsive. Clinicians report some success with SSRI, tricyclic, and monoamine oxidase (MAO) antidepressants, beta-blockers, clonidine (Catapres), anticonvulsants, and benzodiazepines in reducing intrusive symptoms, hyper arousal, and anxiety in patients with dissociative identity disorder.
Patients with obsessive compulsive symptoms may respond to anti-depressants; those with anti-obsessive symptoms may respond to anti-depressants with anti-obsessive efficacy.
Homeopathic treatment of amnesia symptoms – Homeopathy is one of the most popular holistic systems of medicine. The selection of remedy is based upon the theory of individualization and symptoms similarity by using holistic approach. This is the only way through which a state of complete health can be regained by removing all the sign and symptoms from which the patient is suffering. The aim of homeopathy is not only to treat amnesia but to address its underlying cause and individual susceptibility. As far as therapeutic medication is concerned, several medicines are available for amnesia treatment that can be selected on the basis of cause, sensation, modalities of the complaints. For individualized remedy selection and treatment, the patient should consult a qualified homeopathic doctor in person. There are some specific homeopathic remedies which are quite helpful in amnesia treatment.
Belladonna, Anacardium, Hyoscyamus, Digitalis, Arnica Montana, Plumbum Met, Mercurius, Kali Phos, Natrum Mur, Natrum Carb, Zincum Met, Hypericum, Veratrum Album and many other medicines.
Lippincott Williams & Wilkins- Interpreting signs and symptoms; 2007; 28-29
RON DOCTOR, Ronald M. Doctor, Frank N. Shiromoto- The Encyclopedia of Trauma and Traumatic Stress Disorder; 2009; 11
Benjamin J. Sadock, Harold l. Kaplan, Virginia A. Sad- Kaplan & Sadock’s synopsis of psychiatry: behavioral science/clinical Book Year- 2007; 674