Clinical review

Partial seizures presenting as panic attacks

Siân A Thompson, senior house officer, John S Duncan, professor, Shelagh J M Smith, consultant clinical neurophysiologist. 

National Hospital for Neurology and Neurosurgery, London WC1N 3BG

Correspondence to: S A Thompson, Medical Research Council Cognition and Brain Sciences Unit, Cambridge CB2 2EF SianAT{at}aol.com

The diagnosis of partial epileptic seizures is often challenging. The problem is considerable; the lifetime prevalence of epilepsy is 3-4%, and 60% of those affected have simple or complex partial seizures. ^{1 2} Panic disorder has a lifetime prevalence of about 1.5% and is characterised by discrete episodes of unexpected, sudden, overwhelming terror accompanied by a variety of physical, cognitive, and behavioural symptoms.³

Panic disorder and some partial seizures may have similar symptoms. Patients with epilepsy may have prodromal symptoms of tension, anxiety, and depression. Temporal lobe seizures commonly include affective symptoms, fear, and autonomic features, including changes in skin colour, blood pressure, and heart rate.⁴ In comparison, for panic attack to be diagnosed (Diagnostic and Statistical Manual of Mental Disorders, fourth edition) patients must have at least four of 13 symptoms, including physical symptoms (palpitations, sweating, trembling, sensation of breathlessness, chest pain, feeling of choking, nausea, faintness, chills or flushes, and paraesthesiae) and affective symptoms, including fear of losing control, fear of dying, and derealisation or depersonalisation. ^{3 5} There is, therefore, considerable overlap of symptoms between the two disorders, and a definitive diagnosis may be difficult. We describe three patients with partial seizures that were suggestive of panic disorder.

	Case reports

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Case 1
A 68 year old man presented with a four year history of stereotyped attacks that occurred 10 to 14 times daily. These began with the sensation of pins and needles in his head, spreading to his torso and limbs. His breathing became rapid, and he developed a dry mouth, nausea, and a feeling of unease. The symptoms developed and receded gradually. He would be pale, sweaty, agitated, and tearful during the attacks, which lasted between one and four minutes.

Case 2
A 30 year old woman presented with a 10 year history of stereotyped episodes. These began with a pain in her head, hyperventilation, and palpitations, followed by tingling over the left side of her face and left arm, diminution in hearing, left sided chest pain, fear, and a dry mouth. The symptoms built up and diminished gradually, the episode lasting for 15 to 30 minutes. Her husband had recently noted swallowing and chewing movements during the episodes, which occurred in clusters up to 15 times a week.

Case 3
A 47 year old woman presented with a four year history of attacks. Initially these were brief episodes of perception of a smell similar to burning candles, which occurred once a fortnight. There was no loss of consciousness or abnormal movements during the attacks. Initial investigations, including computed tomography of the brain and 24 hour electroencephalography, gave normal results. She was diagnosed as possibly having complex partial seizures and was prescribed sodium valproate, carbamazepine, and then phenytoin, with little change in frequency of attacks.

	Discussion

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Differentiating partial seizures from panic disorder can be difficult on the basis of symptoms but is clearly important.^6-8 Historical features may aid diagnosis. In case 1, the age of onset (64 years) would be unusual for panic disorder, which rarely presents for the first time after 45 years. A witness's account of motor automatisms, such as repetitive swallowing in case 2, favours a diagnosis of complex partial seizures. The duration of the attack may be helpful; partial seizures tend to be much shorter than panic attacks, which can last between 5 and 30 minutes.⁹ Hyperventilation, palpitations, fear, and anxiety are unreliable diagnostic criteria, as these cases demonstrate.

If supposed panic attacks are unresponsive to treatment or the history suggests atypical features (see box), referral to a neurologist should be considered. A magnetic resonance imaging scan of the brain may be useful, as in case 2, but cannot diagnose the nature of episodes, and routine electroencephalography may give normal results in patients with partial seizures (up to four wake and sleep recordings on electroencephalography may be needed to identify interictal epileptiform discharges in 90% or more of patients with confirmed epilepsy).¹⁰ The cases described show the value of prolonged electroencephalography in the differentiation of epileptic from non-epileptic attacks and the classification of seizure type.¹¹ Concomitant videotaping has the advantage of recording a patient's behaviour during an attack, allowing correlation with any changes on the electroencephalogram.

	Acknowledgments

   Contributors: SAT researched and wrote the article. JSD is the consultant to whom the patients were referred and who identified this topic for publication. SMS reported on the electroencephalography and video electroencephography telemetry.

	Footnotes

Competing interests: None declared.

	References

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(Accepted 21 January 2000)