Benign Partial Seizures of Adolescence—A Common Disorder Rarely Described

Abstract & commentary

Source: King MA, et al. Benign partial seizures of adolescence. Epilepsia 1999;40(9):1244-1247.

Periodically, neurologists stumble across a disease that may be fairly common, yet is not well known. Such is the case for the diagnosis of benign partial seizures of adolescence (BPSA). Originally described by Loiseau and Orgogozo in 1978 (Loiseau P, Orgogozo JM. Lancet 1978;2:1070-1071), the syndrome received relatively little attention until now. Loiseau and Orgogozo originally described a retrospective series of 145 patients who first experienced a seizure or cluster of seizures of focal onset that did not recur for at least five years. Seizures frequently secondarily generalized. The EEG of these patients was typically normal or had non-focal abnormalities. These patients with BPSA constituted 24% of a group of retrospectively selected patients who experienced a first focal seizure between 12 and 18 years of age. Although the syndrome found its way into textbooks, few data have been collected on this group of patients prior to the current prospective study of King and colleagues.

From a database of 300 consecutive patients older than 5 years of age who presented with a first unprovoked seizure, King et al identified 92 who were between 10 and 20 years old. Of this group, 37 (40%) had partial epilepsy, 45 (49%) had generalized epilepsy, and 10 could not be classified. Of the patients with partial epilepsy, eight (22%) satisfied the diagnostic criteria of Loiseau and Orgogozo for BPSA. By way of comparison, four patients (11%) were diagnosed with benign Rolandic epilepsy, a well-known syndrome of childhood, five patients had structural lesions accounting for their seizures (14%). Ten patients (27%) had temporal lobe epilepsy, a common seizure type that may begin in adolescence.

The features of BPSA were the following: 1) seizures beginning focally followed by a sensory or motor march’ and frequent generalization; 2) normal MRI; 3) absence of a family history of seizure; 4) neurologically normal with no history of antecedent illnesses that might predispose to seizures; 5) normal interictal EEGs, except for two EEGs recorded within eight hours of a seizure, that expressed focal paroxysmal discharges. Patients were followed between 2-3.2 years. Three patients received treatment with carbamazepine. In follow-up, four patients had no further seizures and three others had persistent occasional simple seizures. One patient developed recurrent tonic-clonic seizures after carbamazepine was slowly tapered. King et al conclude that adolescent patients who present following a first unprovoked seizure characterized by a sensory or motor march, and who have a normal brain MRI, are likely to have a good outcome to their illness.

Commentary

This study offers a method of distinguishing patients with new-onset focal seizures and a good prognosis from patients presenting in a similar manner in whom the prognosis is more guarded. As King et al note, the presence of focal sensory or motor seizures with description of a march of symptoms raises the clinician’s concern for an organic lesion. In this report, King et al update the description of BPSA first presented by Loiseau and Orgogozo and offer prospective evidence that this entity is more common than epileptogenic structural lesions. Armed with these results, clinicians will be better prepared to decide whether to treat and to offer reassurance to patients and families. —fal & slm (Dr. Solomon L. Moshé is Professor and Director, Pediatric Neurology and Clinical Neurophysiology, Department of Neurology, Montefiore Medical Center-Albert Einstein College of Medicine.)