[Torticollis and C1-C2 rotation subluxation. Apropos of a case. The value of a dynamic scanner and of a 3-dimensional scanner]

The authors report the rare and complex case of a girl who had been followed since the age of 3 years for hydrocephalus the cause of which was found only when she was 6-year old. The causative agent was a pilocytic astrocytoma of the cerebellum. On April 10, 1990, she underwent subtotal excision of the tumour, associated with radiotherapy. Four months later she developed an increasingly painful and irreducible torticollis which did not respond to tractions. Dynamic CT scans and 3-dimensional CT scans were performed in the fourth month and provided a diagnosis of right C1-C2 rotatory subluxation. There was no history of injury and no sign of inflammatory process. Rotatory subluxation is a very rare lesion difficult to diagnose, and few cases have been published, although the signs are those of classical torticollis in children. When medical treatment fails, often due to belated diagnosis, the only surgical treatment is uni- or bilateral C1-C2 arthrodesis. If the diagnosis can be made at an early stage, reduction of the rotatory luxation is usually easy and without consequences to the child. It is therefore recommended to perform a dynamic CT scan and a 3D CT scan as soon as possible in all children with lasting painful torticollis.

Synthesis and characterization of kaliotoxin. Is the 26-32 sequence essential for potassium channel recognition?

Kaliotoxin (KTX), a scorpion toxin characterized as a 37-residue inhibitor of the neuronal high conductance Ca(2+)-activated K+ channels (KCa channels), has been chemically synthetized. Differences were observed between natural toxin and the two peptides, KTX(1-37) and KTX(1-37)-amide. Re-examination of the KTX sequence showed that an extra lysine residue was present at the C-terminal end. The 38-residue synthetic peptide was found identical with natural toxin. All three peptides had comparable activities, with LD50 values of 6-9 pmol/mouse after intracerebroventricular injection, and Kd = 2-8 nM for blockage of the whole cell and unitary molluscan KCa currents. Pairing of the disulfide bonds in synthetic KTX corresponded to that in charybdotoxin and iberiotoxin. A competition assay between 125I-KTX(1-37) and different toxins (KTX, dendrotoxin, charybdotoxin, MCD peptide, and iberiotoxin) for binding to rat brain synaptosomal membranes suggested that KTX interacts also with voltage-gated K+ channels. Shorter peptides, KTX(25-35)-amide and KTX(26-32)-amide, expressed no KTX activity, but were able to compete in binding. They were further shown to antagonize KTX in both its toxicity and blocking activity. The (26-32) sequence of KTX, which is a highly conserved region, may contain a low affinity binding subsite essential for potassium channel recognition.

Single-channel and whole-cell recordings from on-neurone glial cells in Helix pomatia ganglia

A procedure is described for performing patch-clamp recordings on satellite glial cells kept in place within the nervous ganglia in the mollusc Helix. Glial cell properties were deduced from whole-cell and cell-attached recordings. The glial membrane was found to contain densely packed inwardly rectifying K+ channels. Activation of the neurones, under either current-clamp or voltage-clamp conditions, depolarized the glial cell layer wrapped around the neurones and induced a delayed persistent increase in the K+ channel opening probability. These results suggest that the glial channels opened in response to a signal emanating from the active neurones. This preparation provides a useful means of detecting and analysing neurone-glial interactions at the cell and unitary channel levels.

Satellite glial cells in situ within mammalian prevertebral ganglia express K+ channels active at rest potential

Patch-clamp experiments were performed on satellite glial cells wrapped around sympathetic neurons in the rabbit coeliac ganglion. With the cleaning method used, the glial cells could be kept in place and were directly accessible to the patch-clamp pipettes. Whole-cell recordings showed that glial cells had almost ohmic properties. Their resting potential (-79.1 +/- 1.2 mV) was found to be very nearly the same as the K+ reversal potential and approximately 20 mV more negative than that of the neurons they encapsulated. Unitary currents from ionic channels present in the glial membrane were recorded in the cell-attached configuration with pipettes filled with various amounts of K+, Na+ and gluconate. Only K(+)-selective channels with slight inwardly rectifying properties (in the presence of 150 mM [K+]o) were detected. These channels were active (Po = 0.7-0.8) at the cell resting potential. The channel conductance, but not its opening probability, was dependent on the [K+] in the pipette. Cl(-)-selective channels (outwardly rectifying and large conductance channels) were detected in excised patches. The properties of the K+ channels (increased inward current with [K+] and detectable outward current at low [K+]) are well suited for siphoning the K+ released by active neurons.

[A rare psychogenic anejaculation. Report of a case of prolactin adenoma]

The authors report a case of prolactinoma discovered during assessment of a case of ejaculation failure attributed for more than eight years to a psychogenic cause. Because of the size of the tumour, surgical resection of the lesion left a persistent hyperprolactinaemia, which only returned to normal after treatment with bromocriptine. The persistence of sexual disorders justified adjuvant treatment with exogenous testosterone. Despite the unusual mode of presentation of hyperprolactinaemia, these data correspond to those reported in the literature. Prolactin assay should therefore be performed in any case of male sexual dysfunction to allow the early diagnosis of prolactinoma and to improve the functional prognosis.

Kaliotoxin, a novel peptidyl inhibitor of neuronal BK-type Ca(2+)-activated K+ channels characterized from Androctonus mauretanicus mauretanicus venom

A peptidyl inhibitor of the high conductance Ca(2+)-activated K+ channels (KCa) has been purified to homogeneity from the venom of the scorpion Androctonus mauretanicus mauretanicus. The peptide has been named kaliotoxin (KTX). It is a single 4-kDa polypeptide chain. Its complete amino acid sequence has been determined. KTX displays sequence homology with other scorpion-derived inhibitors of Ca(2+)-activated or voltage-gated K+ channels: 44% homology with charybdotoxin (CTX), 52% with noxiustoxin (NTX), and 44% with iberiotoxin (IbTX). Electrophysiological experiments performed in identified nerve cells from the mollusc Helix pomatia showed that KTX specifically suppressed the whole cell Ca(2+)-activated K+ current. KTX had no detectable effects on voltage-gated K+ current (delayed rectifier and fast transient A current) or on L-type Ca2+ currents. KTX interacts in a one-to-one way with KCa channels with a Kd of 20 nM. Single channel experiments were performed on high conductance KCa channels excised from the above Helix neurons and from rabbit coeliac ganglia sympathetic neurons. KTX acted exclusively at the outer face of the channel. KTX applied on excised outside-out KCa channels induced a transient period of fast-flicker block followed by a persistent channel blockade. The KTX-induced block was not voltage-dependent which suggests differences in the blockade of KCa channels by KTX and by CTX. Comparison of KTX and CTX sequences leads to the identification of a short amino acid sequence (26-33) which may be implicated in the toxin-channel interaction. KTX therefore appears to be a useful tool for elucidating the molecular pharmacology of the high conductance Ca(2+)-activated K+ channel.

[Hand-Schüller-Christian disease with tumor localization in the posterior fossa]

A 19-year-old girl had been suffering since the age of 4 from Hand-Schüller-Christian disease. The condition was diagnosed by biopsy of a cranial bone lacuna. Later on, she developed diabetes insipidus and bilateral exophthalmos, both being typical signs of Hand-Schüller-Christian disease. At the age of 14, an intracranial tumour in the posterior cerebral fossa was discovered by computerized tomography, but in view of her parent's refusal of surgery, she was operated upon only 4 years later for obstructive hydrocephalus with intracranial hypertension. Two years after this operation, she presented with neurological signs of compression of the medulla oblongata, including tetraparesis and respiratory disorders, and the tumour was resected. Following a brief improvement she died of major hydroelectrolytic disorders due to her irreducible unstable diabetes insipidus. A review of the literature on Hand-Schüller-Christian disease and its rare association with intracranial tumours is analysed. The occurrence of such tumours raise important therapeutic problems and make the prognosis considerably worse.

Degenerative spondylolisthesis, synovial cyst of the zygapophyseal joints, and sciatic syndrome: report of two cases and review of the literature

Two cases of sciatica secondary to nerve root compression by a "synovial cyst" of a zygapophyseal joint are described. In light of these 2 cases and on reviewing the literature, it appears that zygapophyseal joint osteoarthritis with degenerative (or articular) spondylolisthesis can be a predisposing factor to the formation of such synovial expansions and, consequently, the cause of nerve root compression. The coexistence of a lumbar degenerative spondylolisthesis with a radicular syndrome should therefore encourage early investigation by computed tomography scan, so that conservative treatment would not be unnecessarily prolonged.

Lipoma in the cerebellopontine angle

A case of lipoma in the cerebellopontine angle is reported. Intracranial lipomas are very rare, especially in the cerebellopontine angle. To our knowledge, only four cases, including our own, have been operated upon. Until now, total extirpation has not been possible. The singular appearance on computed tomography scanning of this dysembryoplasia is presented together with a bibliography of this subject.

[Intracranial septic aneurysm in an infant. Apropos of a case and review of the literature]

This case report describes a four and a half month old infant with all meningitis symptoms and a sub arachnoidal hemorrhage at the lumbar puncture. Transfontanelle - ultrasonography and computed tomography enables us to diagnose a right intra-cerebral hematoma. Angiography visualises a mycotic aneurysm in a distal portion of the sylvian artery. A success is obtained both by neuro surgery and antibiotics treatment. Regarding this case of intra cranial septic aneurysm and the ones reviewed in the literature, aetiology, frequency, clinical features and management are discussed by the authors.

[Paraplegia with a cauda equina syndrome due to stenosis of the spinal canal caused by tabes arthropathy]

The authors present a case of cauda equina paraparesis due to compression by tabetic osteo-arthropathy. Diagnosis was confirmed by the typical clinical picture of tabes and by the history of a chancre 53 years earlier. Radiography of the spine showed vertibral osteo-arthropathy. Opaque contrast myelography showed compression at the D 11/D 12 and L 4/L 5 levels, with poor contrast filling athe the L 1/L 3 level. Surgical treatment by decompressive laminectomies from D 12 to L 4 led to a satisfactory result with motor recovery and regression of the cauda equina syndrome.

[Metastases of the cervico-occipital junction. The value of tomographic detection of prefracture forms (author's transl)]

The authors stress the frequency of metastases of the cervico-occipital junction unrecognized in medical literature: 30 cases have been diagnosed within four months. They report their different patterns and complications and insist on the prefractured pattern with osteolysis of the body of C-2 which can be shown only by polytomography. The authors propose that a tomographic study of the cervico-occipital junction should be systematically included in every analysis of metastatic extension of osteophilic tumors.

[Intrasellar epidermoid cyst (author's transl)]

The authors present a case of epidermoid cyst in an unusual (intrasellar) situation and with untypical symptomatology (endocrine disorder without ophthalmological manifestations). The treatment was essentially surgical, and the patient's progress has been satisfactory.

[Large partially thrombosed pseudo-tumoral aneurysm of the aqueductal area]

Authors are reporting a case of a giant sylvian aneurism partially thrombosed which had given some tumor like symptoms. The Peumography performed, just before an angiography showed the exact size and the malformation's relations with the lateral ventricle. During the operation, the complete removal of the aneurismatic mass had been done. The follow up was good.