[Nosology of Lennox-Gastaut syndrome]. / Zur Nosologie des Lennox-Gastaut-Syndroms.

After a short historical review, the symptomatology of the Lennox-Gastaut syndrome (LGS) as described in the past 30 years is summarized. Next, all papers published in the past 25 years and presenting the author's own patients are critically reviewed. These considerable patient data enabled to some extent supplementary statistical evaluation of the symptoms and signs of LGS. However, only three of the papers reported largely similar symptom complexes whose components were often combined. While not adequate to allow statistical evaluation, these data have been reviewed with descriptive analysis. The resulting diagnostic criteria correspond to those established by Gastaut in 1982 and are convincing because of their frequency of appearance. In addition, they confirm the 1989 description of LGS by the Commission on Classification and Terminology of the International League Against Epilepsy. These criteria and their frequency are: (1) diffuse slow spike waves in the EEG (100%). (2) tonic seizures (94%), (3) atypical absences (80%), (4) runs of rapid spikes in NREM sleep (approx. 70%), (5) status epilepticus (60%), (6) atonic seizures (43%). Resistance to therapy and persistence of epilepsy are amongst the most frequent features. Mental retardation is a leading symptom, occurring on average in 90% of cases. Reliable statistical analysis of the electroclinical data should be performed following the numerical taxonomy and should provide nosological entities and classifications based on objective, reliable and logical fundamentals. This is an indispensable prerequisite for differential diagnosis. Sections follow which discuss recent morphological and neurometabolic findings concerning the etiology as well as the genetics of LGS. The discussion of the differential diagnosis outlines the nosological delineation of LGS from epilepsy with myoclonic-astatic seizures, benign partial epilepsy of childhood with centrotemporal sharp waves, certain focal epilepsies of the frontal and temporal lobe. Lastly, the myoclonic variant of LGS is discussed. This review shows how frequently in the past LGS was investigated using deficient methodology. Additional studies should be undertaken in collaboration with experienced statisticians in order to complement the above analysis of the syndrome.

[Encephalitis. Recent clinical, diagnostic and therapeutic aspects]. / Enzephalitiden. Neuere klinische, diagnostische und therapeutische Aspekte.

The subjects of this paper are mainly the encephalitis of viral origin and in addition 3 types of non-viral encephalitis of practical importance. A review is given on the current diagnostic possibilities including; clinical criteria; examination of the cerebrospinal fluid; neuroradiology and; etiological investigation by means of direct identification of the microbes in the cerebrospinal fluid or by measuring intrathecally produced antibodies. After some general statements concerning treatment the specifically treatable encephalitis caused by Herpes simplex virus, Mycoplasma pneumoniae, Borrelia burgdorferi and Toxoplasma gondii are discussed in more detail.

Septo-optic pituitary dysplasia. Observations on three patients.

Septo-optic pituitary dysplasia is a relatively rare but pathophysiologically interesting malformation of the brain midline structures including optic chiasm and nerves, hypothalamus, neurohypophysis and septum pellucidum. The lesion develops between the 5th and 8th week of pregnancy. The cause is unknown but heredity seems unlikely. Symptoms result from hypothalamic and neurohypophyseal insufficiency of variable severity combined with reduced vision due to hypoplasia of optic nerves and chiasm. Prognosis is variable, depending on the severity of the defect as well as on the earliest time of diagnosis followed by suitable hormone substitution and specialized care of blindness. We present the clinical course in three patients and the pathological findings in one patient who died in the 14th month of life.

Connatal polyneuropathy -- a case with proliferated microfilaments in Schwann cells.

A case of connatal polyneuropathy is described in a boy who died of pneumonia at the age of 2 years, and from whom sural nerve biopsies had been taken when he was 4 and 16 months old. Clinically, his disease was characterized by motor weakness and muscular flaccidity in the presence of normal intellectual development. The evolution of the connatal peripheral nerve lesion could be followed from the age of 4 months to death: The first biopsy evidenced the most serious pathologic changes. The findings were reminiscent of those encountered in a fetal nerve at 18 weeks of gestation. Furthermore, it showed numerous filamentous inclusions in Schwann cells. The second biopsy showed a sparsely myelinated nerve with bands of basement membrane apparently unrelated to cells arranged around the nerve's fibers. A few Schwann cells containing filamentous inclusions were still present. At autopsy, the findings were identical to those of the second biopsy. The possibility that this patient was transitionally exposed to a neurotoxic agent during pregnancy and that the biopsy findings represent a lesion that is still florid in the first and in a residual state in the second biopsy is considered.

Myoclonic encephalopathy of infants or "dancing eyes syndrome". Report of 7 cases with long-term follow-up and review of the literature (cases with and without neuroblastoma).

We describe 7 children with myoclonic encephalopathy of infants (MEI). MEI is a clinical entity characterized by an acute or subacute onset of polymyoclonia, cerebellar ataxia and opsoclonus ("dancing eyes"). It occurs either spontaneously, following an infectiuos illness or in association with an occult neuroblastoma. It is likely that immunological factors play a role in the pathogenesis. Steroid therapy resulted in rapid dramatic improvement of the neurological symptoms in 4 cases. However, this initial response did not correlate with the eventual outcome. We reviewed the literature to compare 45 reported cases of MEI associated with a neuroblastoma with 48 children without such a tumor to identify possible differences in clinical presentation, response to steroid medication and long-term prognosis of the neurological syndrome. In this respect we found no differences. Impairment of motor, verbal or intellectual performance were reported in at least half the cases. Although an immediate and marked response to steroids occurs in many cases of both groups, it remains unclear whether the long-term outcome is favourably influenced by this medication. The two-year-survival rate (90%) in the neuroblastoma group and the percentage of mediastinal localisation of the tumor (49%) are much higher compared with neuroblastomas without MEI. The reasons for these remarkable differences are not known. Diagnostic, therapeutic and prognostic implications justify the separation of MEI from the more common and benign syndrome known as acute cerebellar ataxia of childhood.

Cerebellar ganglioglioma in a child.

A cerebellar ganglioglioma was surgically removed from a two-year old boy, who had developed manifestations of increased intracranial pressure and cerebellar symptoms. At surgery, the tumor presented as a firm nodular mass displacing the cerebellar cortex. By light microscopy, its architecture differed distinctly from that of hamartomatous diffuse hypertrophy of the cerebellar cortex (Lhermitte-Duclos' disease). Mature ganglion cells were grouped in clusters and linked by thick bundles of nerve cell processes. Nerve cells and processes were enmeshed in a rich network of fibrillary connective tissue. Electron microscopy disclosed typical neuronal perikarya as well as numerous asymmetric chemical synapses. The bulk of the tumor consisted of tightly grouped, (non-myelinated) nerve cell processes arranged in parallel. One of the most prominent features of the tumor consisted of numerous dilatations of these processes. The largest ones contained microfilaments, while the smaller ones were entirely filled with dense bodies (most probably derived from degenerating mitochondria). Only scattered dense core vesicles were seen, which probably did not represent neurosecretory granules. A second cell type consisted probably of astrocytes. Most neuroepithelial cell processes could not be identified with certainty as being of either neuronal or glial origin. A third cell type consisted of numerous slender cells which were probably mesenchymal. They were surrounded by a network of basement membrane which extended between the surrounding nerve cell processes.

Circulating interferon in man after administration of exogenous human leukocyte interferon.

Interferon was measured at different intervals after the iv, sc, and im application of exogenous human leukocyte interferon to patients with various virus diseases or neoplasms. Interferon injected iv into patients had a half-life of about 15 minutes in the 1st hour and of about 90 minutes in the next 3 hours. Six hours after iv injection of 30 million U, no serum interferon was detectable. With a continuous iv infusion, a relatively high serum interferon level was reached. By the im administration of 1 million U interferon, a peak level of serum interferon (mean value 107 U/ml serum) occurred after 2 hours and was fairly stable for about 6 hours. Twenty-four hours after im application, a low level of serum interferon was still detectable. Similar results were found after sc interferon injections. In a patient with subacute sclerosing panencephalitis, no interferon was found in the cerebrospinal fluid at the time of the highest serum interferon level and 24 hours after two im interferon injections. Only minimal side reactions resulted from sc and im interferon injections. In one patient, a shock reaction occurred after iv application. For therapeutic trials, about 1 million U exogenous human interferon should be injected twice daily im or sc.