Wednesday, January 13, 2010

‘Panic’ derives its meaning from the Greek god ‘Pan’ who was in the habit of frightening humans and animals ‘out of the blue’.

Panic attack: It is a period of intense fear characterized by a group of symptoms (given below) that develop rapidly, reach a peak intensity in about 10 minutes, and generally do not last longer than 20-30 min (rarely over 1 hr). Attacks may be either spontaneous (‘out of blue’) or situational (usually where attacks have occurred previously). Sometimes attacks may occur during sleep (nocturnal panic attacks), and rarely, physiological symptoms of anxiety may occur without psychological component (non-fearful panic attacks).

Panic disorder: The recurrent panic attacks, which are not secondary to substance misuse, medical conditions, or another psychiatric condition. There are distinct episodes of intense fear and discomfort associated with a variety of physical symptoms. The frequency of occurrence may vary from many attacks a day, to only a few attacks a year. There is usually the persistent worry of having another attack or the consequences of attack (which may lead to phobic avoidance of places or situations) and significant behavioural changes related to attack.

Epidemiology: In India the prevalence rate of panic disorder in psychiatry clinics is around 3 %. Panic disorder without agoraphobia is more or less equal among males and females, but panic disorder with agoraphobia is more among females. It develops in early adulthood, the mean age of onset being around 25 years.

Aetiology and Psychopathology:
The exact etiology of panic disorder is unknown but appears to involve a genetic predisposition, altered autonomic responsivity, and social learning. Panic disorder has a moderate heritability of around 30 – 40 %. Most studies suggest that vulnerability is genetically determined, but critical stressors are required to develop clinical symptoms.
Intravenous infusion of sodium lactate can evoke an attack in about two-thirds of the panic disorder patients, as do yohimbine and carbon dioxide inhalation.
Neuroanatomical model of aetiology suggests that panic attacks are mediated by ‘fear network’ in brain that involves the amygdale, the hypothalamus and the brain stem centres.
Psychoanalytic model suggests that panic attacks are the consequences of parental deprivation in early childhood.

Clinical features:
The diagnosis of panic disorder is based on the following criteria:-
A separate period of intense fear or discomfort in which four (or more) of the following symptoms are developed abruptly and reach the peak within 10 minutes (in order of frequency of occurrence):
1. Palpitations, pounding heart, or accelerated heart rate.
2. Sweating. 3. Trembling or shaking.
4. Sense of shortness of breath or smothering.
5. Feeling of choking. 6. Chest pain or discomfort
.7. Nausea or abdominal discomfort.
8. Feeling dizzy, unsteady, light-headed, or faint.
9. Derealisation (feelings of unreality) or depersonalization (being
detached from oneself).
10. Fear of losing control or going crazy. 11. Fear of dying.
12. Paresthesia (numbness or tingling sensations).
13. Chills or hot flushes.
In some individuals, anticipatory anxiety develops over time and results in a generalized fear and a progressive avoidance of places or situations in which a panic attack might recur.
Researches suggest that individuals with panic disorder had a significantly higher rate of supporting gastrointestinal symptoms, including those typically associated with irritable bowel syndrome, than those with other or no psychiatric diagnosis.
Differential Diagnosis:
A wide variety of conditions can present as panic disorder.
a. Substance or alcohol misuse / withdrawal.
b. Mood disorders/other psychiatric disorders secondary to medical
C.Medical conditions presenting with similar conditions e.g. hyperthyroidism, hypoglycaemia, anaemia, mitral valve prolapse, atrial tachycardia, coronary heart disease, epilepsy, asthma etc.

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