Palpitations: could they be neurogenic? A case report

Palpitations caused by a Seizure with Autonomic Features

Palpitations are a common symptom of presentation in medical practice. They are usually caused by cardiac arrhythmias, psychiatric problems or other miscellaneous causes, such as anaemia or endocrine causes. They are rarely due to autonomic seizures. We report a 55-year-old woman who presented at Sultan Qaboos University Hospital, Oman, with recurrent episodes of palpitations. Her associated symptoms included breathlessness and excessive sweating, followed by a sensation of dizziness. During subsequent episodes, she experienced symptoms of rising abdominal pain followed by a loss of consciousness. Positive electroencephalogram findings, as well as the response of the symptoms to antiepileptic drugs, were strongly suggestive of temporal lobe epilepsy as the possible diagnosis. The fact that the cardiac investigations, performed during an interictal period, were unremarkable also supports the hypothesis that the palpitations were linked to seizures. Epilepsy should be considered as a differential diagnosis of palpitations, especially if the palpitations are episodic.

Autonomic activity during desflurane anesthesia in patients with brain tumors

OBJECTIVE

Although intracranial tumors may affect autonomic function, there are few reports of autonomic changes during anesthesia. The purpose of this study was to evaluate autonomic effects of anesthesia in patients with brain tumors compared to neurosurgical controls.

METHODS

Two groups were evaluated: group 1 = 10 neurosurgical patients undergoing spinal cord surgery, group 2 = 10 patients with intracranial tumors. After placement of electrocardiogram and Response Entropy electroencephalogram (EEG) electrodes, 10 min baseline measures were made. Heart periods were transformed into a percentage index and heart rate entropy determined as a measure of variance of autonomic activity. Tone was evaluated as the balance between accelerator and inhibitory activity. Tone-entropy was measured during propofol anesthetic induction and the first 60 min of desflurane anesthesia before the start of surgery.

RESULTS

Blood pressure and heart rate were similar between the groups. Starting at awake levels, vagal heart tone was observed. Anesthesia decreased vagal dominance to near zero in both groups. Heart rate entropy and EEG activity decreased during anesthesia with no significant difference between the groups. Desflurane concentrations required to maintain anesthesia were significantly lower in patients in brain tumors.

CONCLUSION

Tone-entropy analysis of heart rate indicates anesthetic related depression of autonomic activity with no difference between groups. Normal titration of desflurane concentrations to maintain adequate blood pressure produced desflurane requirements that were lower in patients with brain tumors, while autonomic and EEG activity were similar.