AIMP1 deficiency presents as a cortical neurodegenerative disease with infantile onset.

We report the second family with AIMP1 deficiency, due to a homozygous truncating AIMP1 (g.107248613 C > T) mutation. This female showed early-onset developmental arrest, intractable epileptic spasms, microcephaly, and a rapid clinical course leading to premature death, associated with cerebral atrophy and myelin deficiency on brain MRI. Clinical and neuroimaging findings are consistent with a primary neuronal degenerative disorder, rather than with the previously reported Perlizaeus-Merzbacher-like phenotype. Given its critical role in neurofilament assembly 16, impaired myelin formation is due to neuronal/axonal dysfunction. We propose that AIMP1 deficiency be added to the differential diagnosis of infantile onset, progressive neurodegenerative disease.

Novel FAM126A mutations in hypomyelination and congenital cataract disease.

Hypomyelination and congenital cataract (HCC, OMIM #610532) is a rare autosomal recessive disorder due to FAM126A mutations characterized by congenital cataract, progressive neurologic impairment, and myelin deficiency in the central and peripheral nervous system. We have identified two novel mutations in three affected members of two unrelated families. Two sibs harbouring a microdeletion causing a premature stop in the protein showed the classical clinical and neuroradiologic HCC picture. The third patient carrying a missense mutation showed a relatively mild clinical picture without peripheral neuropathy. A residual amount of hyccin protein in primary fibroblasts was demonstrated by functional studies indicating that missense mutations are likely to have less detrimental effects if compared with splice-site mutations or deletions that cause the full-blown HCC phenotype, including peripheral nervous system involvement.

[Occupational health and safety and gender differences: need for the identification of an adequate risk assessment]. / Salute, sicurezza sul lavoro e differenze di genere: necessità di una adeguata valutazione dei rischi.

Recent legislation has made mandatory to perform the risk assessment taking into account gender differences. This should imply to consider not only the simple differences due to biologic difference between male and female workers, but also what is more related to the social role they really play in the current society. This second aspect of gender difference has not yet been addressed from a technical point of view. The University of Pisa in cooperation with INAIL has recently started a project aimed at identifying technical tools to perform a risk assessment which took into account gender difference.

Cognitive profile in spastic paraplegia with thin corpus callosum and mutations in SPG11.

Autosomal recessive hereditary spastic paraplegia with thinning of the anterior corpus callosum (ARHSP-TCC) due to mutations in SPG11 on chromosome 15q (MIM610844) is the single most common cause of ARHSP. It is characterized by slowly progressive paraparesis and peripheral neuropathy. Although cognitive impairment, sometimes diagnosed as mental retardation, is an almost invariable feature, the extent and specific neuropsychological features are not fully understood. We report a comprehensive neuropsychological assessment in two ARHSP-TCC patients harbouring mutations in SPG11. A specific impairment in executive functions occurring even before cognitive decline, may be considered the core of the neuropsychological profile of patients harbouring mutations in SPG11.

Enhancing cranial nerves and cauda equina: an emerging magnetic resonance imaging pattern in metachromatic leukodystrophy and krabbe disease.

We report on three cases of infantile Krabbe disease and one case of infantile metachromatic leukodystrophy showing magnetic resonance (MR) imaging findings of diffuse and coexistent cranial nerve and cauda equina nerve roots enhancement. Such findings may be simultaneous, or even precede, typical white matter abnormalities and, in the appropriate clinical context, may facilitate an earlier diagnosis. There is a rational for the use of contrast agents and craniospinal MR imaging during the first imaging of children with a history of psychomotor regression and clinical evidence of peripheral nerve involvement to exclude differential diagnoses.

POMT1 and POMT2 mutations in CMD patients: a multicentric Italian study.

Mutations in POMT1 and POMT2 genes were originally identified in Walker-Warburg syndrome (WWS) and subsequently reported in patients with milder phenotypes characterised by mental retardation with or without brain abnormalities and without ocular malformations. As part of a multicentric Italian study we screened the POMT1 and POMT2 genes in 61 congenital muscular dystrophy (CMD) patients with alpha-dystroglycan reduction on muscle biopsy and/or clinical and radiological findings suggestive of the known forms of CMD with alpha-dystroglycan deficiency. The aim of the study was to establish how frequently mutations in POMT1 and POMT2 occur in CMD patients in the Italian population and to evaluate the spectrum of associated phenotypes. Thirteen patients showed mutations in POMT1 and five harboured mutations in POMT2, accounting for a total of 20 different mutations, eight of which were novel (two in POMT1 and six in POMT2). Normal brain MRI associated with mental retardation and microcephaly was the most frequent finding in patients with mutations in POMT1 (six out of 13), but was also found in a patient with POMT2 mutations. Predominant cerebellar hypoplasia was also frequent both in patients with POMT1 (three out of 13) and POMT2 (three out of 5) mutations. A MEB phenotype with frontal cortical dysplasia and pons abnormalities was found in two patients with POMT1 and in one with POMT2 mutations, while a WWS phenotype was only found in a case with mutations in POMT1. Mutations causing frameshifts and stop codons were responsible for the more severe phenotypes. Our results provide further evidence that, as previously reported for FKRP, the array of mutations in POMT1 and POMT2 is ample and the spectrum of associated phenotypes is wider than initially thought.

Genotype-phenotype correlation in five Pelizaeus-Merzbacher disease patients with PLP1 gene duplications.

Pelizaeus-Merzbacher disease (PMD) is an X-linked myelination disorder most frequently caused by duplication of a genomic segment of variable length containing the PLP1 gene. We studied five PMD male patients affected by the classic PMD form carrying a PLP1 gene duplication. On the basis of clinical and neuroradiological features, two of the five patients appeared to be the most severely affected. In order to establish a possible genotype-phenotype correlation, the extent of the duplication was determined in each patient and in the respective mother by quantifying the copy number of genomic markers surrounding the PLP1 gene by a real-time PCR-based approach. Duplications, ranging in size from 167-195 to 580-700 kb, were in the same genomic interval of the majority of the reported duplications. The extent of the duplicated genomic segments does not correlate with the clinical severity. Interestingly enough, each duplication had one of the two breakpoints in or near to low copy repeats (LCRs), supporting recent evidence concerning a possible role of LCRs in the generation of the duplications in PMD.

Aicardi-Goutières syndrome presenting atypically as a sub-acute leukoencephalopathy.

Aicardi-Goutières syndrome is an autosomal recessive encephalopathy characterised by acquired microcephaly, basal ganglia calcifications, leukodystrophy, cerebral atrophy, chronic cerebrospinal lymphocytosis, and raised titres of interferon alpha in the cerebrospinal fluid. The disease onset is generally within the first months of life. We here report a case of Aicardi-Goutières syndrome presenting atypically as a sub-acute leukoencephalopathy following satisfactory psychomotor development up to the age of 16 months. This case highlights the importance of considering Aicardi-Goutières syndrome in the differential diagnosis of an unexplained leukoencephalopathy and the possibility of later onset of the disease.

Screening of 25 Italian patients with Niemann-Pick A reveals fourteen new mutations, one common and thirteen private, in SMPD1.

Niemann-Pick disease (NPD) results from the deficiency of lysosomal acid sphingomyelinase (SMPD1). To date, out of more than 70-disease associated alleles only a few of them have a significant frequency in various ethnic groups. In contrast, the remainder of the mutations are rare or private. In this paper we report the molecular characterization of an Italian series consisting of twenty-five NPD patients with the severe neurodegenerative A phenotype. Mutation detection identified a total of nineteen different mutations, including 14 novel mutations and five previously reported lesions. The known p.P189fs and the novel p.T542fs were the most frequent mutations accounting for 34% and 18% of the alleles, respectively. Screening the alleles for the three common polymorphisms revealed the variant c.1516G>A (exon 6) and the repeat in exon 1, but not the variant c.965C>T (exon 2). In absence of frequent mutations, the prognostic value of genotyping is limited. However, new genotype/phenotype correlations were observed for this disorder that could in the future facilitate genetic counseling and guide selection of patients for therapy.

Hypersomnia in the Prader Willi syndrome: clinical-electrophysiological features and underlying factors.

OBJECTIVE: Excessive daytime sleepiness is a common symptom in Prader Willi syndrome (PWs). Sleep disordered breathing (SDB) and narcoleptic traits such as REM sleep onsets (SOREMPs) have been reported in these subjects. We evaluated nighttime and daytime sleep patterns in patients with PWs in order to clarify the nature of their hypersomnia. DESIGN AND METHODS: We performed overnight continuous EEG-polysomnographic studies (with breathing monitoring included) in 14 subjects (6 M,8 F; mean age 17 years, range 8-37) affected by PWs unselected for sleep disturbances. Ten patients underwent a Multiple Sleep Latency Test (MSLT) the day following the nocturnal sleep studies. Patients assessment was completed by means of immunogenetic characterization. RESULTS: Nocturnal polysomnographic investigation documented sleep related breathing abnormalities such as central apneas, hypopneas or hypoventilation which mainly occurred during REM sleep in 8 subjects and did not cause sleep disruption. Only 4 subjects presented an increase in the Respiratory Disorder Index (RDI) slightly above the normal limits. In 8 subjects out of 10, with and without SDB, the mean daytime sleep latency could be considered abnormal according to the Tanner staging of pubertal development. Five patients showed at least two SOREMPs at MSLT. Subjects with and without SOREMPs had, respectively, a mean age of 18.6 SD 7.9 (4 M, 1 F) and 14.5 SD 2.9 (4 F, 1 M). The paternal deletion:uniparental dysomy ratio at genotypic characterization was 4:1 and 3.5:1 in subjects with and without SOREMPs, respectively. No patient presented DR-15 nor Dq-6. CONCLUSIONS: Excessive sleepiness is a frequent disturbance in PWs. Subgroups of PW patients show hypersomnolence and SOREMPs. Sleep disordered breathing appears to have a limited role in the genesis of hypersomnia which not seems on the other hand attributable to the coexistence of narcolepsy phenotype. Hypersomnia in PW syndrome is likely to mainly be attributable to a primary hypothalamic dysfunction. The potential interacting role of other factors such as subjects age, sex and genetic pattern is suggested and deserve further investigation.

Early-onset combined methylmalonic aciduria and homocystinuria: neuroradiologic findings.

BACKGROUND AND PURPOSE: Combined methylmalonic aciduria and homocystinuria (MMA-HC) is caused by impaired hepatic conversion of dietary cobalamin to methylcobalamin and adenosylcobalamin, resulting in decreased activity of methylmalonyl-CoA mutase and methionine synthase. Patients with the early-onset variety present within 12 months of age with severe neurologic, hematologic, and gastrointestinal abnormalities. We describe the neuroradiologic features of early-onset MMA-HC and discuss related pathophysiological mechanisms. METHODS: Twelve infants with hypotonia, failure to thrive, poor feeding, and hematologic abnormalities were diagnosed with MMA-HC on the basis of a typical plasmatic and urinary metabolic profile and enzyme activity in fibroblastic cultures. Complementation studies were performed in two cases, and yielded a CblC result. MR imaging was performed at presentation in four cases and later in the others. All patients showed prompt biochemical improvement with intramuscular hydroxocobalamin administration, and most had moderate neurologic improvement. RESULTS: Diffuse supratentorial white matter edema and dysmyelination was the typical MR picture at presentation, whereas white matter bulk loss characterized later stages of the disease. Nucleocapsular areas of gliosis were an additional finding in one case. One patient had tetraventricular hydrocephalus at presentation. CONCLUSION: White matter damage is probably caused by reduced methyl group availability and nonphysiological fatty acids toxicity, whereas focal gliosis results from homocysteine-induced toxicity to the endothelium. Hydrocephalus may result from diffuse intracranial extracerebral arterial stiffness, known as reduced arterial pulsation hydrocephalus. MR imaging features at presentation and at follow-up are nonspecific.

Malignant migrating partial seizures in infancy.

A previously unreported epileptic condition characterised by onset before 6 months of age, nearly continuous electroencephalographic seizures involving multiple independent areas originating in both hemispheres, no identifiable cause, and poor outcome has been described by Coppola et al. We report three cases presenting the same clinical and EEG pictures. They show a peculiar epileptic condition unlike the other early epileptogenic encephalopathies, so they may represent a new infantile epileptic syndrome.

Neurophysiological findings in a case of carbohydrate-deficient glycoprotein (CDG) syndrome type I with phosphomannomutase deficiency.

The carbohydrate-deficient glycoprotein (CDG) syndromes are multisystemic disorders involving the glycosylation pathway. The most common subtype is CDG syndrome type I (CDG I). In most CDG I patients a phosphomannomutase (PMM) deficiency has been recognized as the basic defect. We made a neurophysiological evaluation in an 8-year-old boy affected by CDG I with PMM deficiency. The evaluation included central and peripheral nervous system assessment [electroencephalogram (EEG), multimodal evoked potentials (MEP), somatosensory evoked potentials (SEP), visual evoked potentials (VEP), auditory brainstem response (ABR), electroretinogram (ERG) and motor and sensory nervous conduction velocity (NCV)]. We found a peculiar electrophysiological pattern characterized by slowly and mildly progressive motor NCV reduction; progressive impairment of ERG and VEP; slowing of background activity and sharp waves at the EEGs; late sensorineural abnormality of ABR; decreased amplitude and increased latency of SEP. To our knowledge this is the first report involving the neurophysiological aspects both at onset and during follow-up of a case of CDG I with proven PMM deficiency.

Magnetic resonance imaging of spinal dysraphism.

Spinal cord development occurs through three consecutive periods. Gastrulation (weeks 2-3) is characterized by conversion of the embryonic disk from a bilaminar to a trilaminar arrangement and establishment of a notochord. Primary neurulation (weeks 3-4) produces the uppermost nine tenths of the spinal cord. Secondary neurulation and retrogressive differentiation (weeks 5-6) result in formation of the conus tip and filum terminale. Defects in these early embryonic stages produce spinal dysraphisms, which are characterized by anomalous differentiation and fusion of dorsal midline structures. Spinal dysraphisms may be categorized clinically into two subsets. In open spinal dysraphisms, the placode (non-neurulated neural tissue) is exposed to the environment. These disorders include myelomeningocele, myeloschisis, hemimyelomeningocele, and hemimyelocele, and are always associated with a Chiari II malformation. Closed spinal dysraphisms are covered by intact skin, although cutaneous stigmata usually indicate their presence. Two subsets may be identified based on whether a subcutaneous mass is present in the low back. Closed spinal dysraphisms with mass comprise lipomyeloschisis, lipomyelomeningocele, meningocele, and myelocystocele. Closed spinal dysraphisms without mass comprise complex dysraphic states (ranging from complete dorsal enteric fistula to neurenteric cysts, split cord malformations, dermal sinuses, caudal regression, and spinal segmental dysgenesis), bony spina bifida, tight filum terminale, filar and intradural lipomas, and persistent terminal ventricle. Magnetic resonance imaging is the imaging method of choice for investigation of this complex group of disorders.

Electrical status epilepticus in childhood: treatment with short cycles of high dosage benzodiazepine (preliminary note).

A treatment of electrical status epilepticus during childhood with relatively high doses of benzodiazepines (BZ) in short cycles (3 weeks) is proposed for subjects shown to be responsive to BZs (diazepam bolus test: DZP test). This treatment gave positive results in 7 out of 8 patients responsive to the DZP test (87%).

Clinical and EEG findings in 18 cases of late infantile neuronal ceroid lipofuscinosis.

The objective of this study was to present clinical and electroencephalographic findings in 18 cases with late infantile neuronal ceroid lipofuscinoses, focusing on features that assist early diagnosis. Clinical and EEG findings have been described in the past for classic types, but several variants have recently been reported. The authors reviewed the clinical and EEG findings of 18 childhood onset neuronal ceroid lipofuscinoses cases. In the late infantile neuronal ceroid lipofuscinoses type, both typical and variant cases have been observed. In this type, the presence of a particular pseudoperiodic EEG pattern that we found in 15/18 patients and observed in the first stages of the disease could be useful in early diagnosis, especially if associated with the absence of sleep spindles. A precise nosological classification, based both on clinical and instrumental findings is the prerequisite for a correct genotype-phenotype correlation that could greatly improve our knowledge of this disease, providing a better understanding of pathogenesis and increasing our ability to treat it.

Spinal dysraphism: MR imaging rationale.

Spinal cord development occurs through the three consecutive periods of gastrulation (weeks 2-3), primary neurulation (weeks 3-4), and secondary neurulation (weeks 5-6). Spinal cord malformations derive from defects in these early embryonic stages, and are collectively called spinal dysraphisms. Spinal dysraphisms may be categorized clinically into open and closed, based on whether the abnormal nervous tissue is exposed to the environment or covered by skin. Open spinal dysraphisms include myelomeningocele and other rare abnormalities such as myelocele, hemimyelomeningocele, and hemimyelocele, and are always associated with a Chiari II malformation. Closed spinal dysraphisms are further divided into two subsets based on whether a subcutaneous mass is present in the low back. Closed spinal dysraphisms with mass comprise lipomyelocele, lipomyelomeningocele, meningocele, and myelocystocele. Closed spinal dysraphisms without mass comprise simple dysraphic states (tight filum terminale, filar and intradural lipomas, persistent terminal ventricle, and dermal sinuses) and complex dysraphic states. The latter category involves abnormal notochordal development, either in the form of failed midline integration (ranging from complete dorsal enteric fistula to neurenteric cysts and diastematomyelia) or of segmental agenesis (caudal agenesis and spinal segmental dysgenesis). Magnetic resonance imaging is the imaging modality of choice for evaluation of this complex group of disorders.

Anti-NMDAR encephalitis misdiagnosed as Hashimoto's encephalopathy.

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a well-defined autoimmune disorder. Hashimoto's encephalopathy (HE) is a still controversial entity, lacking definite diagnostic criteria. We described a 14-year-old-girl presenting with a clinical picture consistent with the diagnosis of anti-NMDAR encephalitis, confirmed by NMDAR antibody testing. Four years earlier, she had presented a similar episode of acute encephalopathy diagnosed as HE. Anti-NMDAR encephalitis and HE share similar clinical features so that the differential diagnosis can be difficult if specific antibodies are not tested. The correct diagnosis of anti-NMDAR encephalitis is crucial to plan the appropriate management and follow-up, namely in term of oncological screening, since it can be paraneoplastic in origin. We suggest to re-evaluate the clinical history of all subjects with previous HE diagnosis in order to evaluate the possible diagnosis of anti-NMDAR encephalitis and plan the appropriate management of these patients.

The shrunken, bright cerebellum: a characteristic MRI finding in congenital disorders of glycosylation type 1a.

SUMMARY: CDG-1a is an early-onset neurodegenerative disease with selective hindbrain involvement and highly variable clinical presentation. We retrospectively reviewed the clinical records and MR imaging studies of 5 children (3 boys and 2 girls aged 12 days to 2 years at presentation) with molecularly confirmed CDG-1a. The cerebellum was hypoplastic at presentation in 4 cases, progressive bulk loss involved the cerebellum and the pons in all cases, and the cerebellar cortex and subcortical white matter were hyperintense on T2-weighted and FLAIR images in all. We conclude that CDG-1a likely results from a combination of cerebellar hypoplasia and atrophy. Cerebellar volume loss with diffuse T2/FLAIR hyperintensity seems to be a peculiar association in the field of cerebellar atrophies, and may be useful to address the differential diagnosis.