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Biomedical subjects

B Pohlmann-Eden

Publications and source records attributed to B Pohlmann-Eden.

At least 37 records · Page 2Linked to original sources
PubMed1998

Modified approach for the selective treatment of temporal lobe epilepsy: transsylvian-transcisternal mesial en bloc resection.

OBJECT: The authors propose a novel surgical approach for amygdalohippocampectomy (AH) in patients with temporal lobe epilepsy. Via a transsylvian-transcisternal route, the parahippocampal gyrus is directly exposed from its medial aspect, thus allowing a standardized en bloc resection of the temporomesial epileptogenic structures--the amygdala, anterior hippocampus, parahippocampal gyrus, and subiculum. Additional anatomical studies have been performed for standardization of this approach. METHODS: From 1990 to 1996, 32 patients presenting with medically intractable mesial temporal lobe epilepsy underwent AH via the transsylvian-transcisternal approach. Preoperative computerized tomography and magnetic resonance imaging revealed temporomesial lesions in 16 patients. Histopathological examination revealed cavernous malformations in seven patients, low-grade astrocytomas in four, hamartomas in three, and gangliogliomas in two patients. Specimens obtained in patients with no lesions were diagnosed as hippocampal sclerosis in all cases. No patient experienced permanent morbidity. Nine percent of the patients developed a temporary partial oculomotor nerve palsy. Only one patient developed a postoperative visual field deficit with a contralateral quadrantanopsia. With respect to seizure outcome, all patients benefited from surgery. At follow-up evaluation (mean 26.4 months), 80% of the patients were free from seizures (Engel Class I). Eight patients in this group were no longer receiving medication. Seventeen percent had experienced only one to several seizures since surgery (Engel Class II) and 3% reported a worthwhile improvement (Engel Class III). CONCLUSIONS: In contrast to previously described standard techniques for AH, the transsylvian-transcisternal approach presented in this study offers improved anatomical orientation and intraoperative control over the mesial temporal lobe and preserves the lateral as well as the laterobasal temporal lobe.

Adolescent↗
PubMed1997

Combined electroencephalography and measurements of transcranial blood flow velocity during orthostatic testing--a new approach to assess syncope of unknown origin?

Differential diagnosis of syncope and seizures frequently imposes a major problem, particularly if interictal examinations are normal. We performed orthostatic testing combined with surface electroencephalography (EEG) and non-invasive measurements of cerebral blood flow velocity. Ten healthy controls, ten patients with confirmed diagnosis of epilepsy and 25 patients with history of syncope of unknown origin were examined. The following parameters were evaluated continuously and simultaneously during orthostatic challenge: computerized EEG with synchronous video-monitoring, transcranial Doppler sonography (TCD), heart rate and blood pressure. Isolated cerebrovascular dysregulation (i.e. a drop in cerebral perfusion despite the absence of a significant drop in peripheral blood pressure) occurred in 2/10 controls, 3/10 patients with epilepsy and 11/25 patients with syncope of unknown origin. The combined EEG and TCD measurements represent a new approach to the work-up of patients with otherwise unexplained syncope, helping us to understand the interdependence of neuronal activity and peripheral/cerebrovascular autoregulation under postural stress.

Adolescent↗
PubMed1997

How reliable is the predictive value of SEP (somatosensory evoked potentials) patterns in severe brain damage with special regard to the bilateral loss of cortical responses?

OBJECTIVE: In patients sustaining severe brain damage (SBD), prediction of later outcome is often very difficult, in particular under conditions of therapeutic management like relaxation and intravenous phenobarbital. Somatosensory evoked potentials (SEP) correlated best with later prognosis and expected neurological deficit. In detail, the primary bilateral loss of cortical responses (BLCR) is regarded to be a reliable marker for poor prognosis. The goal of the following prospective study was to reassess the prognostic value of early serial median nerve SEP recording in severe brain damage in comparison to other neurophysiological, clinical, and neuroradiological parameters and, additionally, to test the hypothesis, that the BLCR-pattern is always associated with a poor prognosis and is never reversible. DESIGN: Prospective study. SETTING: Anaesthesiological hospital intensive care unit. PATIENTS AND PARTICIPANTS: 42 comatose patients with severe brain damage (29 males/13 females), mean age 39.6 +/- 19.3 years, mean initial Glasgow Coma Score (GCS) 6.6 +/- 3.1, investigated by means of median somatosensory evoked potentials (SEP) and brainstem auditory evoked potentials (BAEP) with serial recordings on day 1, 3 to 4, and 8 to 1, and repeated cranial computerized tomography. MEASUREMENTS AND RESULTS: We classified the outcome according to the Glasgow Outcome Scale (GOS). Our data showed a high correlation of initial SEP scores (Spearman correlation coefficient = -0.70) with outcome for both a favorable and an unfavorable prognosis (p = 0.0001). The reliability increased with serial recordings. The SEPs showed superiority to parallel brainstem auditory evoked potentials (Spearman correlation coefficient = -0.50, p = 0.0007), GCS, and standardized neuroradiological criteria. Primary (BLCR) occurred in 16 patients (38%) and implied a fatal prognosis in all adult patients (n = 15, specificity = 93.3%, sensitivity = 59.3%). In contrast, a young child with predominant brainstem hemorrhagic contusions regained consciousness and developed mild to moderate neurological deficit (GOS 3-4) during long-term follow-up of 4 years. This clinical improvement paralleled bilateral asymmetric recovery of cortical SEP responses. CONCLUSIONS: SEP allow an early reliable assessment of both poor and good prognosis in SBD, in particular when applied serially. BLCR does not always imply a fatal diagnosis, as a circumscribed contusional lesion rarely may lead to selective reversible blockage of ascending somatosensory pathways in the brainstem. In contradiction to this lesional etiology, a hypoxia-induced BLCR pattern seems to correlate strictly with a poor prognosis, reflecting a different pathogenesis with diffuse destruction of cortex and thalamocortical pathways.

Adolescent↗
PubMed1997

Predictors and dynamics of posttraumatic epilepsy.

OBJECTIVES: The goal of our study was to identify clinical, neurophysiological and neuroradiological variables in severe head trauma (SHT) with predictive value for posttraumatic epilepsy (PTE) and to evaluate the influence of each risk factor for the dynamics of epilepsy. MATERIALS AND METHODS: We systematically compared 57 PTE patients with 50 age and sex-matched control patients with SHT and no PTE. Mean follow-up was 8 years. RESULTS: Of all PTE-patients 68.5% had their first seizure within 2 years after the trauma. Significant risk factors for PTE were focal signs in the first examination (P < 0.01), missile injuries (P < 0.01), frontal lesions (P < 0.01), intracerebral hemorrhage (P < 0.01), diffuse contusion (P < 0.01), prolonged posttraumatic amnesia (P < 0.001), depression fracture (P < 0.01) and cortical-subcortical lesions (P < 0.001). The combination of the last 3 variables conferred a particularly high risk for PTE (logistic regression analysis). Combined seizure pattern, high seizure frequency, AED-noncompliance and alcohol abuse predicted poor seizure control. CONCLUSION: The risk for PTE is clearly determined by those variables which correlate with the severity, the extent of tissue loss and the penetrating nature of the brain trauma.

Adolescent↗
PubMed1996

Periodic lateralized epileptiform discharges--a critical review.

It is the purpose of this review to critically consider and organize the literature dealing with the ephemeral electroencephalographic (EEG) pattern periodic lateralized epileptiform discharges (PLEDs). Although the retrospective nature of these studies limits their ability to discuss accurately the clinical and pathophysiological aspects of this EEG entity, the available data strongly emphasize stroke as the dominant etiology and its high association with seizures. Recent evidence, particularly from functional neuroimaging studies, strongly suggests that PLEDs might reflect a key pattern for focal hyperexcitability in the penumbra zone of ischemic stroke. The authors prefer to consider PLEDs as an EEG signature of a dynamic pathophysiological state in which unstable neurobiological processes create an ictal-interictal continuum, with the nature of the underlying neuronal injury, the patient's preexisting propensity to have seizures, and the co-existence of any acute metabolic derangements all contributing to whether seizures occur or not. This review underlines the need for further sophisticated prospective controlled studies implementing early continuous EEG monitoring in order to contribute to an understanding of the incidence, dynamics, and relevance of this pattern.

Aged↗
PubMed1995

Epileptic seizures in subcortical vascular encephalopathy.

Cerebrovascular disease is one of the most common causes of epilepsy in the elderly. Most of the studies published relate to cortical infarction, subarachnoid, and intracranial hemorrhage, whereas the incidence of epilepsy from subcortical ischemia, i.e. deep lacunar infarctions and diffuse white matter lesions, is obscure. Therefore, we prospectively examined 18 patients with the precisely defined diagnosis of subcortical vascular encephalopathy (SVE), who were admitted to our hospital due to epileptic seizures (group A), and compared them to a similarly selected group matched for age, sex, risk factors, and neurological deficits with an equivalent severity of SVE but without seizures (group B). Subcortical lacunar infarctions were significantly more frequent in group A than group B (15/18 versus 4/18, p < 0.001), whereas neither the extension, degree, distribution of periventricular white matter changes, nor the presence of internal hydrocephalus, focal or diffuse cortical atrophy showed any statistical significance. However, a temporal constant theta or delta EEG focus was present in 10/18 patients in group A but only in 1/18 patients from group B (p < 0.005). 10/18 patients developed epilepsy with further seizures during follow-up. The association of SVE, multiple subcortical lacunas, and temporal EEG abnormalities are suggestive for an increased risk for epileptic seizures, which is particularly important for the treatment of patients with SVE if uncertain paroxysmal episodes occur, e.g. transient ischemic attacks, seizures, or cardiac syncope.

Adult↗
PubMed1994

[Diagnostic and prognostic implications of the first epileptic seizure in adulthood].

Actual epidemiological studies show a prevalence rate for active epilepsy in 0.5-1%, whereas single seizures occur in up to 5% of the general population. Assessment of the significance of first epileptic reaction requires precise definition and classification of the episode, a careful analysis of the entire context including thorough case history, and indirect anamnesis. The value of EEG-techniques for this issue is part of a controversial discussion. By means of cranial computerized tomography (cCT), brain tumours were detected as structural correlate in 5 to 16% of first-seizure-patients. In recent studies, estimated risk of seizure recurrence after first unprovoked seizure ranged from 27% to 78%: most of the relapses were observed in the first 6 months after the first event. The wide range of relapse rates is due to the divergent methodological designs (retro- versus prospective design, selection of patients, length of time before study entry) in the different studies. There are conflicting results concerning risk factors and predictive value of the following variables: pathology in the neurostatus, focal seizure type or Todd's paresis, history of febrile seizures, symptomatic genesis, and specific epileptic potentials and time of day of seizure event. In an actual metaanalysis of recent studies, seizure etiology and EEG were the strongest predictors of recurrence. The preliminary results of our prospective study with a strict protocol and first-seizure-design are presented: we observed a seizure relapse in 26.7% of 78 adult patients (age range: 17-84 years) after a mean latency of 4.4 months. Until now, there is no evidence for potential predictors of seizure recurrence.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

[Rotatory seizures: a rare equivalent of focal epileptic activity. Case report and possible pathophysiology].

We report a typical case of so called "volvular epilepsy" (synonym: retatory seizures, circling epilepsy). Our 59-year-old patient exhibited the characteristic pattern of repetitive walking in small circles, always strictly contralateral to the epileptogenic focus in the right fronto-parietal region. The MRI study indicated a diagnosis of brain tumor in the same area, which was confirmed as an oligodendroglioma. After adequate anticonvulsive treatment there was complete seizure control. Rotatory seizures are rarely reported and usually related to pathological findings in the fronto-temporal region (infarction, neoplasma, giant aneurysm and posttraumatic lesions). Corresponding to the international classification of epileptic seizures, this is a very rare manifestation of a simple partial seizure (without impairment of the conscious state), which can extend to a complex partial seizure (with impairment of consciousness) and secondarily generalized tonic-clonic seizure. In explaining this rare epileptic phenomenon, the controversial concepts (involvement of the striatum, temporal lobe or cortical adverse fields?) are discussed.

Anticonvulsants↗
PubMed1993

[Correlation of serum prolactin and cortisol values with paroxysmal disorders of epileptic and non-epileptic origin and their clinical value].

In 95 patients (44 women and 51 men, aged 14 to 86 yrs., average 44.9 yrs.) the serum levels of prolactin, cortisol and uric acid were investigated 30, 60 and 120 min after seizure-like events. There were 53 fits of epileptic aetiology (EE), mainly tonic-clonic, and 42 attacks of non-epileptic aetiology (NEE). The uric acid of the epileptic patients 30 min postictally revealed significantly higher ratings (p < 0.05) compared to the control group (n = 36), but not compared to the NEE group. Serum cortisol was significantly higher after all investigated disturbances without differences in the EE and NEE group. After epileptic and non-epileptic attacks prolactin was significantly (p < 0.05) elevated in comparison to the baseline. The increase of 3 times the amount of the individual baseline and at the same time exceeding the range of reference were found in 73% of the epileptic and only in 7% of the non-epileptic patients. As hypothesis to the postictal prolactin rise we discuss disturbances in the neurotransmitter equilibrium within the hypothalamic-hypophyseal axis. We regard prolactin as a biochemical marker, which is a valuable aid in the differential diagnosis of epileptic and non-epileptic fits.

Adolescent↗
PubMed1992

[Changes in somatosensory evoked potentials in pharmacogenic myoclonia].

Transient increases of the early cortical somatosensory evoked potentials (SSEP) were observed in 9 patients who received antidepressant and/or neuroleptic treatment. All patients developed myoclonus, and 2 had grand mal seizures. Three cases--one 20-, one 17- and one 15-year-old patient--are presented in detail. Similar observations have been reported in elderly patients. Possible underlying mechanisms and the potential value of the SSEP in identifying and monitoring patients at risk of developing psychotropic drug-induced side-effects are briefly discussed.

Adolescent↗
PubMed1991

Somatosensory evoked potentials as indicators of altered cerebral excitability during psychotropic drug treatment.

We observed an increase in the amplitude of the early cortical somatosensory evoked potentials (SSEPs) in five patients who developed myoclonus and/or generalized seizures during treatment with antidepressants. The increases correlated closely with the course of the clinical disturbances. In every case the SSEPs returned to normal values after the discontinuation of the psychotropic drugs. We suggest that SSEPs might help to identify and monitor patients who are at an increased risk of potentially hazardous side effects during psychopharmacological treatment.

Aged↗
PubMed1991

Muzolimine-induced severe neuromyeloencephalopathy: report of seven cases.

We report on 7 patients (2 women, 5 men) with chronic renal failure, who developed under a high dosage of the new diuretic muzolimine (range 240 to 1440 mg per day) fatal neuromyeloencephalopathy. Clinical neurophysiological and neuroradiological findings and finally neuropathological studies in 2 patients resembled those found in vitamin-B12-deficiency-syndrome with a predominant affection of the spinal posterior column and the corticospinal tracts. The first neurological symptoms like paraesthesia, severe hyperpathia of the legs and mild to heavy spinal ataxia occurred after an average time of treatment of 78 days and a mean dosage of 52 g. The most progressive neurological deficits like severe tetraspastic paresis, were seen only in the nondialytic renal insufficient group (3 patients), while the others had a more benign course of the disease. This lead to the hypothesis of a partially dialysable toxic metabolite of muzolimine. After a follow-up of more than 2 1/2 years no significant recovery was seen in these cases.

Adult↗