Letters

Editor:

The outstanding differential review on firesetting by Burton et al.¹ in the September 2012 issue makes an important contribution to diagnostic clarity. However, these conscientious authors omitted an essential differential-diagnostic category: partial (focal) seizures. Such an omission is understandable, since even the most common type, temporal lobe epilepsy (TLE), has been absent from the table of contents since the Diagnostic and Statistical Manual of Mental Diseases, Third Edition (DSM-III),² constricting psychiatry's realm of expertise. Nonconvulsive behavioral seizures of partial epilepsies, such as TLE, tend to present with paroxysmal bizarre behavioral changes that can mimic various psychiatric syndromes. Neurologically informed psychiatrists are required to diagnose a partial epilepsy in the absence of convulsions. Such psychiatric expertise is necessary, given that even the presently most advanced objective brain tests are not yet consistently positive in partial epilepsies, not even in TLE (due to a deep-lying focus or lack of accurate methods to detect subtle brain dysfunction). Thus, a patient suffering a brief, nonconvulsive, behavioral seizure may be misdiagnosed and inappropriately treated.

As to firesetters, not otherwise diagnosable, one subtype of partial epilepsies with nonconvulsive behavior seizures appears to be of specific interest: the proposed limbic psychotic trigger reaction (LPTR).³ Four of the 24 published cases of LPTR involved firesetters.^4,–,7 The subject of one case⁷ had kept in memory repeated mild-to-moderate experiences related to various aspects of fire. Just before he set fires, such memories had suddenly been revived by a chance encounter with a highly individualized trigger stimulus, actually or symbolically associated with fire.

LPTR invites future research because of its primate model; its analogy to the experimentally established neurophysiological mechanism of seizure-kindling; its specific 12 interrelated symptoms and signs, strictly determined by 16 inclusion and 13 exclusion criteria (all met by the 24 cases); and its similarity to mesotemporobasal limbic seizures,⁷ evoked by direct electrical stimulation of brain implants in presurgery patients. Many more nonfelonious paroxysmal cases with merely socially bizarre misbehaviors may exist undetected (and untreated with antiepileptica) among the general population or among misdiagnoses.

In essence, the central role of memory (in certain cases of LPTR, specifically of fire) is supported by Halgren et al.⁸ in a neuroanatomic comparison of normal hippocampal functioning of repeated memory updating with hippocampal susceptibility to seizures.⁴

Thus, all LPTR patients were social loners who ruminated on mild-to-moderate stresses related to individual experiences with fire.