Ictal automatisms with preserved responsiveness in a patient with left mesial temporal lobe epilepsy

Epilepsy Mimicking Affective Disorder in a Patient with Amygdala Enlargement

Affective disorders are commonly associated with epilepsy. Affective symptoms rarely occur concomitantly with seizure occurrence, which can lead to misdiagnosis. Here, we describe a 69-year-old man who experiencedintermittent manifestations of unpleasant mood and aggressive behavior. He had temporal lobe epilepsy with amygdala enlargement. After successful treatment with an antiepileptic drug, hissymptoms resolved. Additionally, the amygdala enlargement decreased when checked at 5 years after treatment. We discuss the clinical characteristics and differential points of the case.

SPECT perfusion changes during ictal automatisms with preserved responsiveness in patients with right temporal lobe epilepsy

Ictal automatism with preserved responsiveness (APR) has been reported, particularly in nondominant temporal lobe epilepsy (TLE), but its pathophysiology remains poorly understood. This study sought to investigate the relationship between APRs and increased cerebral blood flow (CBF) using ictal single photon emission computed tomography (SPECT) in TLE. Forty-seven subjects with right mesial TLE (15 with and 32 without APR) were enrolled. Patients with APR (APR+) were subdivided into four groups according to degree of responsiveness during seizures. Cerebral blood flow changes during these seizures were semiquantitatively assessed by subtraction ictal SPECT coregistered to MRI (SISCOM). Hyperperfusion in temporal regions did not vary significantly between the APR+ and APR- groups. Cerebral blood flow changes in the frontal area, insula, cingulum, and occipital area were also nonsignificant. However, hyperperfusion in the ipsilateral parietal areas was more frequent in the APR- group than in the APR+ group. Furthermore, hyperperfusion of the contralateral basal ganglia showed an inclination to be more common in the APR- group, but without statistical significance. The study suggested that the involvement of the parietal association cortex during seizure may play an important role in ictal loss of consciousness in TLE. Further studies will be needed to elucidate the pathophysiology of changes in consciousness during temporal lobe seizures.

Lateralizing signs during seizures in focal epilepsy

This article reviews lateralizing semiological signs during epileptic seizures with respect to prediction of the side of the epileptogenic zone and, therefore, presurgical diagnostic value. The lateralizing significance of semiological signs and symptoms can frequently be concluded from knowledge of the cortical representation. Visual, auditory, painful, and autonomic auras, as well as ictal motor manifestations, e.g., version, clonic and tonic activity, unilateral epileptic spasms, dystonic posturing and unilateral automatisms, automatisms with preserved responsiveness, ictal spitting and vomiting, emotional facial asymmetry, unilateral eye blinking, ictal nystagmus, and akinesia, have been shown to have lateralizing value. Furthermore, ictal language manifestations and postictal features, such as Todd's palsy, postictal aphasia, postictal nosewiping, postictal memory dysfunction, as well as peri-ictal water drinking, peri-ictal headache, and ipsilateral tongue biting, are reviewed. Knowledge and recognition of semiological lateralizing signs during seizures is an important component of the presurgical evaluation of epilepsy surgery candidates and adds further information to video/EEG monitoring, neuroimaging, functional mapping, and neuropsychological evaluation.

Early- and Late-onset Complications of the Ketogenic Diet for Intractable Epilepsy

PURPOSE

This study was undertaken to evaluate the exact limitations of the ketogenic diet (KD) and to collect data on the prevention and management of its risks.

METHODS

Patients (129) who were on the KD from July 1995 to October 2001 at our epilepsy center were assessed in the study. Early-onset (within 4 weeks of the commencement of the KD until stabilization) and late-onset complications (occurring after 4 weeks) were reviewed.

RESULTS

The most common early-onset complication was dehydration, especially in patients who started the KD with initial fasting. Gastrointestinal (GI) disturbances, such as nausea/vomiting, diarrhea, and constipation, also were frequently noted, sometimes associated with gastritis and fat intolerance. Other early-onset complications, in order of frequency, were hypertriglyceridemia, transient hyperuricemia, hypercholesterolemia, various infectious diseases, symptomatic hypoglycemia, hypoproteinemia, hypomagnesemia, repetitive hyponatremia, low concentrations of high-density lipoprotein, lipoid pneumonia due to aspiration, hepatitis, acute pancreatitis, and persistent metabolic acidosis. Late-onset complications also included osteopenia, renal stones, cardiomyopathy, secondary hypocarnitinemia, and iron-deficiency anemia. Most early- and late-onset complications were transient and successfully managed by careful follow-up and conservative strategies. However, 22 (17.1%) patients ceased the KD because of various kinds of serious complications, and four (3.1%) patients died during the KD, two of sepsis, one of cardiomyopathy, and one of lipoid pneumonia.

CONCLUSIONS

Most complications of the KD are transient and can be managed easily with various conservative treatments. However, life-threatening complications should be monitored closely during follow-up.

Positive and negative network correlations in temporal lobe epilepsy

Temporal lobe seizures are accompanied by complex behavioral phenomena including loss of consciousness, dystonic movements and neuroendocrine changes. These phenomena may arise from extended neural networks beyond the temporal lobe. To investigate this, we imaged cerebral blood flow (CBF) changes during human temporal lobe seizures with single photon emission computed tomography (SPECT) while performing continuous video/EEG monitoring. We found that temporal lobe seizures associated with loss of consciousness produced CBF increases in the temporal lobe, followed by increases in bilateral midline subcortical structures. These changes were accompanied by marked bilateral CBF decreases in the frontal and parietal association cortex. In contrast, temporal lobe seizures in which consciousness was spared were not accompanied by these widespread CBF changes. The CBF decreases in frontal and parietal association cortex were strongly correlated with increases in midline structures such as the mediodorsal thalamus. These results suggest that impaired consciousness in temporal lobe seizures may result from focal abnormal activity in temporal and subcortical networks linked to widespread impaired function of the association cortex.

Why do seizures cause loss of consciousness?

Model systems are needed for the scientific investigation of consciousness. A good model system should include variable states of consciousness, allowing the relationship between brain activity and consciousness to be investigated. Examples include sleep, anesthesia, focal brain lesions, development, evolution, and epilepsy. One advantage of epilepsy is that changes are dynamic and rapidly reversible. The authors review previous investigations of impaired consciousness in epilepsy and describe new findings that may shed light on both normal and abnormal mechanisms of consciousness. Abnormal increased activity in fronto-parietal association cortex and related subcortical structures is associated with loss of consciousness in generalized seizures. Abnormal decreased activity in these same networks may cause loss of consciousness in complex partial seizures. Thus, abnormally increased or decreased activity in the same networks can cause loss of consciousness. Information flow during normal conscious processing may require a dynamic balance between these two extremes of excitation and inhibition.

Automatisms with preserved responsiveness and ictal aphasia: contradictory lateralising signs during a dominant temporal lobe seizure

The 25-year-old right-handed woman suffering from temporal lobe epilepsy (TLE) was referred to our centre for presurgical evaluation. MRI showed a right-sided hippocampal sclerosis. During video-EEG-recorded seizures, abdominal aura was followed by oral automatisms, during which she was completely reactive to external stimuli, although she was unable to speak. Ictal EEG showed right temporal seizure pattern, without contralateral propagation. She had abnormal speech postictally. Speech-activated functional transcranial Doppler sonography revealed right-sided speech dominance. She has become seizure free after a right-sided amygdalo-hippocampectomy. In our patient, contradictory clinical ictal lateralising signs (automatisms with preserved responsiveness vs. ictal and postictal dysphasia) occurred during right-, speech-dominant-sided seizures. This is the first report when automatisms with preserved consciousness occurred during a seizure originating and involving the speech-dominant hemisphere.