Expanding CEP290 mutational spectrum in ciliopathies.

Ciliopathies are an expanding group of rare conditions characterized by multiorgan involvement, that are caused by mutations in genes encoding for proteins of the primary cilium or its apparatus. Among these genes, CEP290 bears an intriguing allelic spectrum, being commonly mutated in Joubert syndrome and related disorders (JSRD), Meckel syndrome (MKS), Senior-Loken syndrome and isolated Leber congenital amaurosis (LCA). Although these conditions are recessively inherited, in a subset of patients only one CEP290 mutation could be detected. To assess whether genomic rearrangements involving the CEP290 gene could represent a possible mutational mechanism in these cases, exon dosage analysis on genomic DNA was performed in two groups of CEP290 heterozygous patients, including five JSRD/MKS cases and four LCA, respectively. In one JSRD patient, we identified a large heterozygous deletion encompassing CEP290 C-terminus that resulted in marked reduction of mRNA expression. No copy number alterations were identified in the remaining probands. The present work expands the CEP290 genotypic spectrum to include multiexon deletions. Although this mechanism does not appear to be frequent, screening for genomic rearrangements should be considered in patients in whom a single CEP290 mutated allele was identified.

A novel form of ataxia oculomotor apraxia characterized by oxidative stress and apoptosis resistance.

Several different autosomal recessive genetic disorders characterized by ataxia with oculomotor apraxia (AOA) have been identified with the unifying feature of defective DNA damage recognition and/or repair. We describe here the characterization of a novel form of AOA showing increased sensitivity to agents that cause single-strand breaks (SSBs) in DNA but having no gross defect in the repair of these breaks. Evidence for the presence of residual SSBs in DNA was provided by dramatically increased levels of poly (ADP-ribose)polymerase (PARP-1) auto-poly (ADP-ribosyl)ation, the detection of increased levels of reactive oxygen/nitrogen species (ROS/RNS) and oxidative damage to DNA in the patient cells. There was also evidence for oxidative damage to proteins and lipids. Although these cells were hypersensitive to DNA damaging agents, the mode of death was not by apoptosis. These cells were also resistant to TRAIL-induced death. Consistent with these observations, failure to observe a decrease in mitochondrial membrane potential, reduced cytochrome c release and defective apoptosis-inducing factor translocation to the nucleus was observed. Apoptosis resistance and PARP-1 hyperactivation were overcome by incubating the patient's cells with antioxidants. These results provide evidence for a novel form of AOA characterized by sensitivity to DNA damaging agents, oxidative stress, PARP-1 hyperactivation but resistance to apoptosis.

A subgroup of spinocerebellar ataxias defective in DNA damage responses.

A subgroup of human autosomal recessive ataxias is also characterized by disturbances of eye movement or oculomotor apraxia. These include ataxia telangiectasia (A-T); ataxia telangiectasia like disorder (ATLD); ataxia oculomotor apraxia type 1 (AOA1) and ataxia oculomotor apraxia type 2 (AOA2). What appears to be emerging is that all of these have in common some form of defect in DNA damage response which could account for the neurodegenerative changes seen in these disorders. We describe here sensitivity to DNA damaging agents in AOA1 and evidence that these cells have a defect in single strand break repair. Comparison is made with what appears to be a novel form of AOA (AOA3) which also shows sensitivity to agents that lead to single strand breaks in DNA as well as a reduced capacity to repair these breaks. AOA3 cells are defective in the DNA damage-induced p53 response. This defect can be overcome by incubation with the mdm2 antagonists, nutlins, but combined treatment with nutlins and DNA damage does not enhance the response. We also show that AOA3 cells are deficient in p73 activation after DNA damage. These data provide further evidence that different forms of AOA have in common a reduced capacity to cope with damage to DNA, which may account for the neurodegeneration observed in these syndromes.

Pediatric functional neurologic symptoms.

Functional neurologic disorders (FND) of children have many similarities to those of adults, and there is a potential to learn much from the study of FND in children. In this chapter we discuss multiple aspects of pediatric FND. These include their frequency, historic features, the diagnosis, and controversies over the nature of FND and the "correct" name that should be used. We also discuss methods of informing the child and family of the diagnosis, treatment, and prognosis. FND of children typically affect girls in the 10-14-years age range. The presentation is often polysymptomatic, with pain and lethargy accompanying loss of motor function. A common situation is a perfectionistic child who has taken on too much in her academic, sporting, cultural, and social life. Some children respond readily to treatment, but others have a prolonged illness.

Childhood chronic inflammatory demyelinating polyneuropathy: clinical course and long-term outcome.

We reviewed the clinical history, electrophysiologic and pathologic findings, and response to therapy of 16 children with chronic inflammatory demyelinating polyneuropathy. The majority presented with lower limb weakness. Sensory loss was uncommon. The illness was monophasic in seven children, relapsing in six, and three had a slowly progressive course. All patients were treated with immunosuppressive agents. In 11, the initial treatment was prednisolone. All had at least a short-term response but five went on to develop a relapsing course. Intravenous immunoglobulin was the initial treatment in four patients. Three responded rapidly, with treatment being stopped after a maximum of 5 months. In resistant chronic inflammatory demyelinating neuropathy, in addition to prednisolone and immunoglobulin, plasma exchange, azathioprine, cyclosporine, methotrexate, cyclophosphamide and pulse methylprednisolone were tried at different times in different patients. On serial neurophysiologic testing slowing of nerve conduction persisted for long periods after clinical recovery. Follow-up was for an average of 10 years. When last seen 14 patients were asymptomatic, two having mild residual deficits. Childhood chronic inflammatory demyelinating neuropathy responds to conventional treatment and generally has a favourable long-term outcome.

Gillespie syndrome: a report of two further cases.

We describe two unrelated patients with Gillespie syndrome (partial aniridia, cerebellar ataxia, and mental retardation). The typical presentation is the discovery of fixed dilated pupils in a hypotonic infant. The iris abnormality is specific and seems pathognomonic of Gillespie syndrome. It can be distinguished clinically from other forms of aniridia and a presumptive diagnosis of Gillespie syndrome can be made in the first months of life on the basis of the ocular findings. Neurological involvement includes marked motor delay, hypotonia, disabling ataxia, and usually mental retardation. Cerebral and cerebellar atrophy with white matter changes on MRI scan were present in our second patient suggesting that patients with Gillespie syndrome may have more extensive CNS involvement than previously described. The parents of this child were first cousins; thus Gillespie syndrome may be heterogeneous with autosomal recessive and autosomal dominant forms.

Migrating partial seizures in infancy: two new cases.

Two infants presented at 3 weeks and 3 months of age with intractable partial seizures. Extensive investigations failed to identify an underlying cause. There was no response to antiepileptic drug therapy and no developmental progress following the onset of the seizures. In both infants there was a distinctive pattern of seizures that arose independently from multiple regions of both hemispheres. Interictal electroencephalograms revealed multifocal epileptiform activity. The infants died aged 9 and 12 months. One underwent postmortem examination, which was normal with no hippocampal sclerosis. These infants fulfill the diagnostic criteria of the syndrome of migrating partial seizures in infancy described by Coppola and colleagues in 1995.

Intraneural ganglion of the common peroneal nerve in a 4-year-old boy.

The case history of a 4-year-old boy with an intraneural ganglion of the common peroneal nerve is presented. These lesions are rare, more commonly affect males, and typically present with a painful foot-drop. A mass is often palpable adjacent to the neck of the fibula. Our patient has made a good recovery after surgery.

The value of partial sleep deprivation as a routine measure in pediatric electroencephalography.

For more than 50 years it has been known that in patients with epilepsy, sleep markedly increases the diagnostic yield of the electroencephalogram (EEG). Sleep deprivation could have an additional activating role. Many laboratories do not use these methods routinely but reserve them for a second EEG if equivocal or negative findings are present in the initial EEG. We studied a regime of routine partial sleep deprivation without the use of hypnotic agents in 396 children younger than age 17 years who were referred for EEG with a diagnosis of epilepsy or suspected epilepsy. Sleep was achieved for the EEG in 77% (96% in the 1 month to 2 year age group, 78% in the 2 to 8 year age group, and in 64% of those more than 8 years old). In a comparison group of 72 children who had not been sleep-deprived, sleep was achieved in 44% (69% of those less than 2 years old, 27% of those between 2 and 8 years of age, and 33% of those older than 8 years). The differences were highly significant. The regime was well tolerated. Routine partial sleep deprivation is a practical and effective method of obtaining sleep and thus maximizing the information obtained from a single EEG.

Acute respiratory failure precipitated by general anesthesia in Leigh's syndrome.

Three patients with Leigh's syndrome developed respiratory failure following general anesthesia. Although all three had respiratory symptoms prior to the anesthetic, the diagnosis was not suspected at the time of the procedure in two of the children. We reviewed the case notes of 16 other patients with Leigh's syndrome. Eight had received anesthetic agents without incident. Although the majority subsequently developed respiratory abnormalities and died with respiratory failure, this problem was not evident at the time of anesthesia. In the presence of respiratory abnormalities, general anesthesia carries significant risks in Leigh's syndrome.

Acute pseudobulbar palsy due to bilateral focal cortical damage: the opercular syndrome of Foix-Chavany-Marie.

Two children are described who suddenly developed an encephalitic illness with intractable bilateral facial seizures. The seizures subsided over several days, but the children were left with the signs of pseudobulbar palsy and are unable to speak or swallow effectively. Bilateral destructive lesions in the opercular regions evolved on computed tomographic scans. Both children were treated with acyclovir relatively early in the illness, and cerebrospinal fluid and serum antibodies support the diagnosis of herpes simplex virus encephalitis.

Spinal muscular atrophy: molecular mechanisms.

Spinal muscular atrophy (SMA) is a relatively common autosomal recessive neuromuscular disorder characterised by muscle weakness and atrophy due to degeneration of motor neurons of the spinal cord and cranial motor nuclei. The clinical phenotype incorporates a wide spectrum. No effective treatment is currently available and patients may experience severe physical disability which is often life limiting. The most common type of SMA is caused by homozygous disruption of the survival motor neuron 1 (SMN1) gene by deletion, conversion or mutation and results in insufficient levels of survival motor neuron (SMN) protein in motor neurons. While diagnosis is usually achieved by genetic testing, an illustrative clinical case is described that highlights the molecular and diagnostic complexities. While there is an emerging picture concerning the function of the SMN protein and the molecular pathophysiological mechanisms underpinning the disease, a number of substantial issues remain unresolved. The selective vulnerability of the motor neuron and the site and timing of the primary pathogenesis are not yet determined. Utilising the organisation of the SMN genomic region, recent advances have identified a number of potential therapeutic targets. As such, this review incorporates discussion of the clinical manifestations, molecular genetics, diagnosis, mechanisms of disease pathogenesis and development of novel treatment strategies.

Cerebellar leukoencephalopathy: most likely histiocytosis-related.

BACKGROUND: Histiocytosis, both Langerhans and non-Langerhans cell type, can be associated with cerebellar white matter abnormalities, thought to be paraneoplastic. The associated clinical picture consists of ataxia, spasticity, and cognitive decline. Hormonal dysfunction is frequent. MRI shows cerebellar white matter abnormalities, as well as brainstem and basal ganglia abnormalities. This so-called "neurodegenerative syndrome" may occur years before or during manifest histiocytosis and also years after cure. We discovered similar MRI abnormalities in 13 patients and wondered whether they could have the same syndrome. METHODS: We reviewed the clinical and laboratory information of these 13 patients and evaluated their brain MRIs. Seven patients underwent spinal cord MRI. RESULTS: All patients were isolated cases; 10 were male. They had signs of cerebellar and pyramidal dysfunction, behavioral problems, and cognitive decline. MRI showed abnormalities of the cerebellar white matter, brainstem, basal ganglia, and, to a lesser extent, cerebral white matter. Three patients had spinal cord lesions. Three patients had laboratory evidence of hormonal dysfunction. No evidence was found of an underlying metabolic defect. In two patients biopsy of nodular brain lesions revealed histiocytic infiltrates. CONCLUSIONS: Considering the striking clinical and MRI similarities between our patients and the patients with this neurodegenerative syndrome in the context of proven histiocytosis, it is likely that they share the same paraneoplastic syndrome, although we cannot exclude a genetic disorder with certainty. The fact that we found histiocytic lesions in two patients substantiates our conclusion. Patients with cerebellar white matter abnormalities should be monitored for histiocytosis.

Hypomyelination with atrophy of the basal ganglia and cerebellum: follow-up and pathology.

BACKGROUND AND OBJECTIVE: Hypomyelination with atrophy of the basal ganglia and cerebellum is a recently defined disorder. Only a few patients have been described. We report on 11 additional patients and new MRI findings and provide histopathologic confirmation of the MRI interpretation. METHODS: We reviewed the patients' clinical history and present findings. We scored the MRI abnormalities. The histopathology of one patient was re-examined. RESULTS: The patients' early psychomotor development was normal or delayed, followed by increasing extrapyramidal movement abnormalities, ataxia, and spasticity. Mental capacities were variably affected. MRI showed hypomyelination with, on follow-up, evidence of further myelin loss and variable white matter atrophy. The putamen was small or, more often, absent; the head of the caudate nucleus was decreased in size. In contrast, the thalamus and globus pallidus remained normal. Cerebellar atrophy was invariably present. Histopathology confirmed the myelin deficiency, probably related to both lack of deposition and low-grade further loss. The degeneration of putamen was subtotal. The cerebellar cortex was affected, particularly the granular layer. CONCLUSION: Hypomyelination with atrophy of the basal ganglia and cerebellum is a syndrome diagnosed by distinctive MRI findings. Histopathology confirms hypomyelination, low-grade further myelin loss, subtotal degeneration of the putamen, and cerebellar cortical atrophy. All known patients are sporadic, and the mode of inheritance is unclear.

Suppression of brainstem reflexes in barbiturate coma.

Brainstem reflexes were examined in 23 children treated with thiopentone infusion and correlated with serum thiopentone concentrations. The results suggest that if all brainstem reflexes are lost with a serum thiopentone concentration less than 40 mg/l, it is unlikely to be due to the thiopentone alone. Other causes including brain death need to be considered.

Neurofibromatosis involving the lower urinary tract in children. A report of three cases and a review of the literature.

Three children with neurofibromatosis involving the lower urinary tract are reported and their clinical, radiological and pathological findings are described. Lower urinary tract involvement in neurofibromatosis has previously been reported in 17 children, 12 of whom had other stigmata of von Recklinghausens disease. Lower urinary tract involvement may be asymptomatic and can be found incidentally. Every case with neurofibromatosis presenting with what may appear to be even only insignificant urinary symptoms should be thoroughly investigated urologically. Symptoms are usually related to urinary tract obstruction or neurogenic bladder dysfunction due to the involvement of the nerves supplying the bladder. Urinary diversion is the treatment of choice as surgical removal of the extensive tumour is seldom feasible. Following treatment the prognosis for survival appears to be good.

Clinical features of conversion disorder.

This study reviewed the case notes of 52 children diagnosed as suffering from hysterical conversion during admission to a paediatric teaching hospital over a 10 year period. The disorder was rare below 8 years of age and girls outnumbered boys three to one. Altogether 75% of the children presented during spring and summer; at the time of end of year exams and the beginning of the new school year. The presentation was usually polysymptomatic with gait disturbance being the main complaint in 36 children. Sensory abnormality, predominantly pain, was present in 40 children; this indicates a strong association between psychogenic pain and conversion disorder in children. At discharge 32 were completely recovered or had appreciably improved. There was a core group that presented particular difficulties with diagnosis and showed little positive response to treatment.

Very long chain fatty acids in X-linked adrenoleukodystrophy brain after treatment with Lorenzo's oil.

The fatty acid composition of postmortem brain and liver from an adrenoleukodystrophy patient whose diet was supplemented with Lorenzo's oil (glycerol trioleate and glycerol trierucate) for 9 months was determined. The diet depressed plasma and liver saturated very long chain fatty acids (24:0 and 26:0) and increased plasma and liver erucic (22:1) and nervonic (24:1) acids. The levels of plasma linoleic (18:2 n-6), eicosopentaenoic (20:5 n-3), and docosahexaenoic (22:6 n-3) acids were also reduced, while the biochemical marker for essential fatty acid deficiency (20:3 n-9) was markedly increased in liver. However, we were unable to detect any corresponding changes in brain indicating that little erucic acid crossed the blood-brain barrier. Our findings suggest that dietary supplementation with Lorenzo's oil is of limited value in correcting the accumulation of saturated very long chain fatty acids in the brain of patients with adrenoleukodystrophy.

Status dystonicus and Hallervorden-Spatz disease: treatment with intrathecal baclofen and pallidotomy.

Severe dystonia or status dystonicus is a life threatening disorder that develops in patients with both primary and secondary dystonia. We present the case of a 9-year-old boy with Hallervorden-Spatz disease (HVS) who developed status dystonicus, failing to respond to high dose oral therapy with multiple antidystonic agents. High dose intravenous sedating agents combined with endotracheal intubation and mechanical ventilation were required to control the spasms. Alleviation of the spasms was achieved by a combination of temporary intrathecal baclofen infusions and bilateral pallidotomy. Although it could be argued this is a situation where only palliative measures should be used, we believe a relatively aggressive approach was justified. It relieved the intense pain associated with the spasms and allowed the child to be discharged home without the prolonged stay in intensive care, morbidity and mortality, which characterize status dystonicus.

Delayed radiation necrosis of the central nervous system in patients irradiated for pituitary tumours.

Four cases of delayed radiation necrosis involving the CNS were found in a group of 46 patients irradiated for pituitary tumours over a six year period. This occurred in three of 11 patients with Cushing's disease representing an incidence of 27% in this group. There were no cases among 11 patients with acromegaly or among seven with prolactinomas. One case (6%) was found in the 17 patients with chromophobe adenomas. Standard doses of radiation were delivered to these patients and the findings support suggestions that the metabolic disturbances of Cushing's disease may reduce tolerance to radiation. Our results and a literature review indicate that if radiotherapy is used to treat Cushing's disease, the total dose should be less than 50 Gy at 2 Gy per day fractionation.