Na+-activated K+ current contributes to postexcitatory hyperpolarization in neocortical intrinsically bursting neurons.

The ionic mechanisms underlying the termination of action-potential (AP) bursts and postburst afterhyperpolarization (AHP) in intrinsically bursting (IB) neocortical neurons were investigated by performing intracellular recordings in thin slices of rat sensorimotor cortex. The blockade of Ca(2+)-activated K(+) currents enhanced postburst depolarizing afterpotentials, but had inconsistent and minor effects on the amplitude and duration of AHPs. On the contrary, experimental conditions resulting in reduction of voltage-dependent Na(+) entry into the cells caused a significant decrease of AHP amplitude.

Restoring migraine sufferers' ability to function normally: a comparison of rizatriptan and other triptans in randomized trials.

Background: Many migraine patients are unable to function normally during a migraine attack. Assessments of treatment efficacy have tended to focus on migraine symptoms, rather than looking at functional impact. This study compared the efficacy of different oral triptans for restoring normal function in migraine sufferers.

Mutations of mitochondrial DNA polymerase gammaA are a frequent cause of autosomal dominant or recessive progressive external ophthalmoplegia.

One form of familial progressive external ophthalmoplegia with multiple mitochondrial DNA deletions recently has been associated with mutations in POLG1, the gene encoding pol gammaA, the catalytic subunit of mitochondrial DNA polymerase. We screened the POLG1 gene in several PEO families and identified five different heterozygous missense mutations of POLG1 in 10 autosomal dominant families. Recessive mutations were found in three families.

Behavioral and pharmacologic treatment of transformed migraine with analgesic overuse: outcome at 3 years.

Objective: To determine whether combined treatment using medication and biofeedback would be more effective than drug treatment alone for treating transformed migraine complicated by analgesic overuse.

Background: Headaches that are chronic, daily, and aggravated by medication overuse are particularly difficult to treat.

Methods: Sixty-one consecutive patients with transformed migraine and analgesic overuse were treated with inpatient pharmacologic therapy alone or with inpatient pharmacologic therapy combined with biofeedback-assisted relaxation.

Myoclonic dystonia as unique presentation of isolated vitamin E deficiency in a young patient.

We describe a young patient affected by vitamin E deficiency with mutation in the tocopherol transfer protein alleles and the unique presentation as myoclonic dystonia, which was practically the only symptom for 6 years before ataxia became evident. Vitamin E supplementation markedly improved both symptoms. This unusual clinical phenotype must be considered, because isolated vitamin E deficiency is eminently treatable.

Frequency of DYT1 mutation in early onset primary dystonia in Italian patients.

Thirty Italian patients with sporadic, early-onset, primary dystonia were screened for the DYT1 mutation. Five patients were positive (mean age at onset, 8 years); two had the typical phenotype, two a generalised dystonia also involving the cranial muscles, and one a segmental dystonia. In the other 25 patients (mean age at onset, 7.

Human neural stem cells express extra-neural markers.

Neural stem cells can be derived from the adult/embryonic nervous system as well as from more primitive embryonic stem cells but, because of the lack of specific markers, only their differentiated progeny can be characterized. We here report the presence of several endothelial and hematopoietic receptors (at protein and mRNA level) on the surface of embryonic human neural stem cells, which are partially maintained during differentiation. This suggests that neural stem cells have a greater potential than previously thought, which involves the ability to respond to different and so far unconsidered environmental signals and may be responsible for the recently discovered process of stem cell-fate conversion.

Novel heteroplasmic mtDNA mutation in a family with heterogeneous clinical presentations.

The protean manifestations of a novel maternally inherited point mutation of the mitochondrial genome are reported. The proband showed isolated, spastic paraparesis. A brother, who had suffered from a multisystem progressive disorder, ultimately died of cardiomyopathy.

A novel nonsense mutation (Q352X) in the mitochondrial cytochrome b gene associated with a combined deficiency of complexes I and III.

We identified a novel mitochondrial cytochrome b mutation in a patient with progressive exercise intolerance, muscle cramps and lactic acidosis. A marked reduction of the enzymatic activities of respiratory chain complexes I and III was found in muscle biopsy. The mutation was a heteroplasmic C15800T transition, determining a stop-codon at amino acid position 352 (Q352X).

The perineuronal net: a weapon for a challenge.

Theories and data do not always fit and sometimes are sources of conflicts among scientists. This is the case of a morphological structure, the perineuronal net, which was denied on the basis of an ideological conflict between two giants of neurosciences: Camillo Golgi and Santiago Ramon y Cajal. The perineuronal net is a reticular structure enveloping many neurons.

Mitochondrial disorders.

The most relevant contribution to the elucidation of the molecular basis of mitochondrial disorders has come from the discovery of an impressive and ever expanding number of mutations of mitochondrial DNA. However, known mutations of mtDNA only account for a fraction of all the mitochondrial disorders in both infants and adults. A number of recent clinical and molecular observations indicate that many syndromes are caused by abnormalities in nuclear genes related to oxidative phosphorylation.

Reversal of CSF positivity for JC virus genome by cidofovir in a patient with systemic lupus erythematosus and progressive multifocal leukoencephalopathy.

We report the case of a 36-year-old woman affected by systemic lupus erythematosus who developed rapidly progressive multifocal leukoencephalopathy. Cidofovir therapy induced disappearance of JC virus genome from the cerebrospinal fluid and stabilization of the MRI picture. Despite the fatal outcome after a few months of disease, cidofovir treatment deserves further testing as single antiviral therapy in HIV-negative PML patients.

Epidermal nerve fiber density in sensory ganglionopathies: clinical and neurophysiologic correlations.

We assessed the involvement of somatic unmyelinated fibers in sensory ganglionopathies by skin biopsy and quantitative sensory testing (QST). Sixteen patients with ganglionopathy, 16 with axonal neuropathy, and 15 normal controls underwent skin biopsy at the proximal thigh and the distal leg. Intraepidermal nerve fibers (IENF) were immunostained by antiprotein gene product 9.

The insomnia plague: a Gabriel García Márquez story.

"All the great writers have good eyes" is a sentence by V. Nabokov that is very suitable for G.G.

Clinical and neuroradiological aspects of Sneddon's syndrome and primary antiphospholipid antibody syndrome. A follow-up study.

We performed a study to investigate differences and similarities between patients with Sneddon's syndrome and those with primary antiphospholipid syndrome (PAS), by clinical follow-up, magnetic resonance imaging (MRI) and angiography. Nine patients with Sneddon's syndrome and 11 patients with PAS were assessed at diagnosis and followed for a mean of 6 years. The clinical and MRI findings indicated that Sneddon's syndrome and PAS are distinct entities.

Age-dependent neurologic manifestations of HIV infection in childhood.

Although the neurologic complications of HIV- 1 infection during the first two years of life have been defined, the neurologic features in older children are not so well described. The present report is focused on the age-dependent neurologic presentation of HIV-1 infection. Sixty-two vertically HIV-1 infected children underwent detailed serial evaluations: neurologic assessment, neuropsychological tests, neuroimaging studies, and cerebrospinal fluid analysis.

A pathophysiological study of neuronal ceroid lipofuscinoses in 17 patients: critical review and methodological proposal.

The importance of visual evoked potentials (VEPs) and electroencephalography for diagnosing and distinguishing the infantile (INCL), late-infantile (LINCL) and juvenile (JNCL) forms of neuronal ceroid lipofuscinoses (NCL) is well established. Variant forms with protracted clinical courses and atypical symptoms have been described recently, whose neurophysiological characteristics sometimes overlap those of LINCL and JNCL. It is unclear whether these variant forms are due to phenotypic variability of known genetic defects, or represent new mutations.

Electroencephalographic features in a series of patients with neuronal ceroid lipofuscinoses.

We report the electroencephalographic (EEG) features of 22 patients with neuronal ceroid lipofuscinoses (NCL) who were referred to the Neurological Institute of Milan between 1984 and 1998. The EEG data were reviewed, taking into account the different forms of NCL on the basis of age at onset, clinical features and morphological appearance. The study group included patients with infantile NCL (one case), late-infantile NCL (ten cases), juvenile NCL (seven cases) and adult NCL (four cases).

MRI in neuronal ceroid lipofuscinosis.

Magnetic resonance imaging in neuronal ceroid lipofuscinosis (NCL) demonstrates cerebral and cerebellar atrophy, T2-hyperintensity of the lobar white matter and thinning of the cerebral cortex. The association of these findings, although non specific, can be observed in all the different forms of NCL, narrows the differential diagnosis of the infantile progressive encephalopathies and may suggest the diagnosis.

Neuronal ceroid lipofuscinosis: detection of atypical forms.

The neuronal ceroid lipofuscinoses (NCL) are progressive neurodegenerative diseases occurring in infancy and adulthood. Atypical forms of these diseases have been described and are particularly represented in the late-infantile and juvenile onset groups. Recent progress in biochemistry and molecular genetics has identified some of these variants as separate disease entities while disclosing the phenotypic variability of some classic forms.

Life-threatening dystonia-dyskinesias in a child: successful treatment with bilateral pallidal stimulation.

We report a 13-year-old boy who developed severe, refractory dystonia-dyskinesias as an abrupt worsening of a previously nonprogressive movement disorder. The movements became continuous, requiring artificial respiration and continuous sedation in the intensive-care unit. Various drugs and drug combinations failed to achieve control.

Quality of life and memory performance in patients with temporal lobe epilepsy.

Objective: To explore the contribution of memory performance to quality of life (QOL) in patients with left or right temporal lobe epilepsy (TLE).

Subjects And Methods: Sixty-five patients with left or right TLE compiled the QOL in Epilepsy-89 Inventory (QOLIE-89), the State-Trait Anxiety Inventory (STAI) and the Hopelessness Scale (BDI) for self-evaluation of QOL and mood. Memory was assessed by tests of verbal and non-verbal memory and the Questionnaire of Memory Efficiency (QME).

Chronic inflammatory demyelinating polyradiculoneuropathy: long-term course and treatment of 60 patients.

The objective of this study was to assess the long-term course and treatment of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). We evaluated, according to a predefined protocol, a series of 60 CIDP patients who received a long-term course of steroids and immunosuppressants. Eighteen of them also had monoclonal gammopathy of undetermined significance (MGUS).

Embryonal tumors in the adult population: implications in therapeutic planning.

The natural history of neuroectodermal tumors is still debated as far as prognostic factors are concerned; the same uncertainty applies to the optimal radiotherapy schedule and even more to the presumptive additive effect of chemotherapy. The rarity of these tumors and the heterogeneity of management make interpretation of literature data also more difficult. We evaluated clinical course in a cohort of 39 patients, including 31 with medulloblastoma (MB) and 8 with primitive neuroectodermal tumors (PNET).

Clinical, biochemical and neuroradiological findings in L-2-hydroxyglutaric aciduria.

L-2-Hydroxyglutaric aciduria is a rare inborn error of metabolism, marked by a large and persistent increase of L-2-hydroxyglutaric acid in urine, blood and cerebrospinal fluid (CSF). We present clinical, biochemical and neuroradiological findings of seven Italian patients aged 4-19 years presenting at different stages of the disease. The disorder was characterized by a progressive neurological syndrome with cerebellar and pyramidal signs, mental deterioration, epilepsy and subcortical leukoencephalopathy on magnetic resonance imaging (MRI).