Status epilepticus and frontal lobe lesions

Psychogenic Nonepileptic Seizures-High Mortality Rate Is a 'Wake-Up Call'

Patients with epilepsy have an elevated mortality rate compared to the general population and now studies are showing a comparable death ratio in patients diagnosed with psychogenic nonepileptic seizures. The latter is a top differential diagnosis for epilepsy and the unexpected mortality rate in these patients underscores the importance of an accurate diagnosis. Experts have called for more studies to elucidate this finding but the explanation is already available, embedded in the existing data. To illustrate, a review of the diagnostic practice in epilepsy monitoring units, of the studies examining mortality in PNES and epilepsy patients, and of the general clinical literature on the two populations was conducted. The analysis reveals that the scalp EEG test result, which distinguishes a psychogenic from an epileptic seizure, is highly fallible; that the clinical profiles of the PNES and epilepsy patient populations are virtually identical; and that both are dying of natural and non-natural causes including sudden unexpected death associated with confirmed or suspected seizure activity. The recent data showing a similar mortality rate simply constitutes more confirmatory evidence that the PNES population consists largely of patients with drug-resistant scalp EEG-negative epileptic seizures. To reduce the morbidity and mortality in these patients, they must be given access to treatments for epilepsy.

Tumor-associated status epilepticus: A prospective cohort in a tertiary hospital

INTRODUCTION

Tumor-associated status epilepticus (TASE) follows a relatively benign course compared with SE in the general population. Little, however, is known about associated prognostic factors.

METHODS

We conducted a prospective, observational study of all cases of TASE treated at a tertiary hospital in Barcelona, Spain between May 2011 and May 2019. We collected data on tumor and SE characteristics and baseline functional status and analyzed associations with outcomes at discharge and 1-year follow-up.

RESULTS

Eighty-two patients were studied; 58.5% (n = 48) had an aggressive tumor (glioblastoma or brain metastasis). Fifty-one patients (62.2%) had a favorable outcome at discharge compared with just 30 patients (25.8%) at 1-year follow-up. Fourteen patients (17.1%) died during hospitalization. Lateralized period discharges (LPDs) on the baseline electroencephalography (EEG), presence of metastasis, and SE severity were significantly associated with a worse outcome at discharge. The independent predictors of poor prognosis at 1-year follow-up were SE duration of at least 21 h, an aggressive brain tumor, and a nonsurgical treatment before SE onset. Lateralized period discharges, super-refractory SE, and an aggressive tumor type were independently associated with increased mortality.

CONCLUSIONS

Status epilepticus duration is the main modifiable factor associated with poor prognosis at 1-year follow-up. Accordingly, patients with TASE, like those with SE of any etiology, should receive early, aggressive treatment.

The history of status epilepticus and its treatment

Despite the fact that status epilepticus was been recognized since antiquity, its existence was largely ignored until the mid-nineteenth century. In this review we cover the medical literature of status epilepticus from the late nineteenth century until the early 1970s when the modern era of status epilepticus began. We pay particular attention to the impact of the ILAE and its principal members on the understanding and awareness of status epilepticus. We also cover the evolution of treatment regimens advocated for status epilepticus from the late nineteenth century to the early 1970s when the benzodiazepines were established as first line treatments.

Intractable seizures of frontal lobe origin: clinical characteristics, localizing signs, and results of surgery

PURPOSE

We analyzed the clinical characteristics of seizures of frontal lobe (FL) origin with particular emphasis on establishing different categories and determining if these categories had any localizing or lateralizing value. In addition, results of surgery are reported.

METHODS

Seizure characteristics were established by historical review and electroencephalographic/videotape analysis of 449 seizures in 26 adult patients with refractory seizures of FL origin.

RESULTS

No outstanding risk factor was identified for seizures of FL origin. Seizures were frequent (7.1 per week), brief (mean duration, 48.3 seconds), and had a nocturnal preponderance in 58% of the patients. Status epilepticus was reported in 54%, and generalized convulsions as a prominent seizure type were reported in 26% of patients. The most common reported aura was a nonspecific sensation, often localized to the head (35%). Early forced head and eye deviation was not a consistent lateralizing sign, whereas late head and eye deviation always occurred contralateral to the site of seizure origin. Early asymmetric tonic posturing occurred consistently contralateral to the side of seizure origin. Clinical seizure patterns did not consistently localize to specific regions of the frontal lobe, although there were some noticeable trends: focal clonic seizures were associated with seizure origin in the frontal convexity; tonic seizures were most often associated with origin in the supplementary motor area but also occurred with origin in other parts of the frontal lobe; seizures resembling typical temporal lobe seizures with oroalimentary automatisms were observed with seizure origin in the orbitofrontal region; and seizures with hyperactive, frenetic automatisms were not associated with any specific region within the frontal lobes. Eighty percent of patients had favorable seizure outcome after surgery (class I/II).

CONCLUSION

Although certain clinical features are characteristic for seizures of frontal lobe origin and some have lateralizing value, they do not localize to specific areas within the FL. After careful presurgical evaluation, both lesional and nonlesional patients benefit from epilepsy surgery.

Medical management of recurrent seizures in dogs and cats

The problem of recurrent seizures is a common and challenging one in veterinary medical practice. The pathophysiology and pharmacologic suppression of focal seizure activity have been studied extensively in basic research settings, yet little is known of the genesis, modulation, and termination of generalized seizures, the most common form of seizures noted to occur in companion animals. Knowledge concerning the pharmacokinetic fate of anticonvulsant drugs currently used in veterinary medicine is adequate, though prospective clinical studies of the efficacy of these drugs in the treatment of various types of seizures are lacking. This study will review the available literature regarding the pharmacology, use, and side effects of anticonvulsant drugs currently available for control of recurrent seizures in companion animals. Alternative anticonvulsant drugs will also be described.

Neuropathology of epilepsy

The neuropathology of symptomatic and idiopathic epilepsy is presented. New methods of investigation have disclosed that more cases of epilepsy are symptomatic--even hippocampal sclerosis is now detectable in vivo by MR-scan. It still remains to be defined whether hippocampal sclerosis is the cause or the effect of epilepsy. The present survey focusses upon the delineation of hippocampal neuron loss with a critical discussion of various hypotheses drawn from various human and experimental studies. In particular the phenomenon of selective and delayed neuron loss are explored with regard to future neurosurgical approaches.

Complex partial status epilepticus: a depth-electrode study

Of 87 patients with complex partial epilepsy who were evaluated with depth electrodes, 8 developed complex partial status epilepticus (CPSE). Seizures originated extratemporally in all 8 patients. Frontal lobe onset was established in 4 patients and was probable in 1 more. Medial parietal onset was documented in 1 patient. Medial occipitoparietal onset occurred in another, and 1 patient had multifocal onsets. Even when seizures did not begin frontrally, the frontal lobes were prominently involved during CPSE. CPSE did not occur in 60 patients with seizures originating in the temporal lobe. Both recurrent clinical seizures and continuous altered behavior were observed. Some patients exhibited both clinical patterns at different times during the same episode. Depth recording consistently demonstrated recurrent isolated seizure discharges throughout episodes. The clinical patterns were related, in part, to electroencephalographic seizure frequency, duration, and intensity. Episodes of CPSE were not associated with intellectual deterioration.

Late onset epilepsy. A prospective study

253 cases of late onset epilepsy were studied prospectively. 27 cases (10.7%) had space-occupying lesion, 19 cases (7.5%) had cerebrovascular disease, 13 cases (5.1%) cerebral cysticercosis and 4 cases (1.6%) had diffuse cerebral atrophy. No cause could be detected in 190 cases (75.1%). Analysis of clinical data and radiological studies showed that a majority (85%) of patients with 'tumour' who presented with epilepsy had focal neurological deficit and/or papilloedema. Focal slow-wave abnormality in EEG also gave an indication of an organic lesion. Patients who had epilepsy for more than 1 year, infrequent attacks and partial complex seizures, were less likely to have a tumour. The role of careful clinical examination is stressed.

Status epilepticus. Causes, clinical features and consequences in 98 patients

The etiology, clinical features and outcome of generalized major motor status epilepticus in 98 patients over the age of 14 years have been reviewed. Approximately half of the patients had not had previous seizures. The most common single cause of the status was noncompliance with anticonvulsant drug regimens and this accounted for the status in 53 percent of the patients with previous seizures and in 28 percent of all the patients in our series. The other causes in our series were alcohol-withdrawal, cerebrovascular disease, cerebral tumors or trauma (involving especially the frontal lobe), intracranial infection, metabolic disorders, drug overdose and cardiac arrest. In 15 percent of the patients, however, no specific cause could be found. Status was never the initial manifestation of primary (constitutional) generalized epilepsy in our experience. The etiology of the status was sometime multifactorial, so patients must be screened as fully as possible even when a likely cause is readily apparent. The motor manifestations of the convulsions were frequently restricted in distribution (62 percent of the cases). Focal or lateralized convulsive activity, especially during the course of continued seizure activity, did not necessarily indicate that localized structural pathology was responsible for the status. The seizures were of the tonic variety in a few of our patients and in such circumstances were usually associated with cerebral anoxia. We found that a poor outcome of the status was more likely as its duration increased, and the morbidity rate from the status itself was 12.5 percent among our patients, with a mortality rate of 2.5 percent. The episode of status was usually accompanied by hyperthermia, and often by a brisk peripheral leukocytosis, and in some of our patients a status-induced cerebrospinal fluid pleocytosis also developed. These features may lead to diagnostic confusion if their basis is not recognized. In most of our patients a systemic acidosis developed during the course of the status, but this did not appear to greatly influence the outcome.

The syndrome of isolated epileptic status

Within a group of 23 patients who presented with status epilepticus a syndrome is defined in which sudden unheralded status occurs in apparently healthy individuals. Recovery from the attack is complete and no other evidence of cerebral pathology may be found at the time. In seven of nine such cases studied the final diagnosis at follow-up, either by necropsy or by operation, was of cerebral tumour. In five of the seven the fronto-temporal region was the site of pathology. It is suggested that the occurrence of isolated status indicates a possible cerebral tumour for which careful search should be made and, if negative, follow-up study arranged. Of 20 of our patients with status epilepticus in whom the site of lesion was definite, nine were exclusively frontal and a further six had some frontal involvement. This confirms previous evidence that symptomatic status epilepticus indicates a frontal lesion.

Three cases of frontal meningiomas presenting psychiatrically

The clinical presentation of three patients with meningiomas at different frontal sites is described. They had been ill for 3, 25, and 43 years before the tumour was demonstrated radiologically. Apathy, incontinence, dementia, and fits were seen in association with middle and superior frontal lesions, and may be mistaken for symptoms of involutional depression or presenile cerebral atrophy. In contrast, excitement and hallucinosis were seen in association with a basal frontal lesion, and may mimic psychotic syndromes like hypomania and schizophrenia, particularly if the tumour encroaches on the third ventricle and adjacent structures. Irreversible loss of myelin and axons in the frontal areas of brain surrounding the tumour may have contributed to the clinical picture of the syndrome shown by these patients.