Polyneuropathies in paediatrics

Polyneuropathies in teenagers: A clinicopathological study of 45 cases

The aim of the present study was to investigate the causes of polyneuropathy in teenagers and to describe some characteristic clinical, laboratory, electrophysiological and pathological features. Forty-five patients with peripheral nervous disorders aged 13-19 were studied. Hereditary polyneuropathy of different types was diagnosed in 28 patients (62%); nine showed chronic inflammatory demyelinating polyneuropathy (CIDP) and two showed vasculitic neuropathy. In two more cases polyneuropathy was attributed to toxic agents, while among the rest, one was diagnosed as metachromatic leucodystrophy (juvenile type), one as adrenoleucodystrophy, one as porphyric neuropathy and one as Fabry disease. The high incidence of hereditary neuropathies in teenagers differs from that in adults, but is similar to that encountered in children. In our study, CIDP appears to be a frequent cause of neuropathy in teenagers, while the other causes are broadly similar to those found in studies concerning children rather than adults.

Early peripheral nervous system manifestations of infantile Krabbe disease

Early infantile Krabbe disease is relatively frequent in the Muslim-Arab population in Israel. It can be easily diagnosed when it presents with the classic clinical picture characterized by central nervous system manifestations of spasticity, irritability, motor regression and seizures associated with a positive family history. We studied eight children diagnosed with Krabbe disease. In two of these children (25%), peripheral neuropathy was the single initial symptom and the only neurologic finding noted for a period of months. In these patients, diagnosis of Krabbe's disease was delayed and established only 9-11 months after the initial symptoms. In two other children with "classical picture" Krabbe disease, areflexia was noted on admission. The occurrence of peripheral neuropathy as an initial symptom in early infantile Krabbe disease may be underestimated. Krabbe disease should be considered in the differential diagnosis of early infantile peripheral neuropathy. Early diagnosis of affected children might be important for genetic counseling for families at risk.

Long-term follow-up of children with chronic relapsing polyneuropathy

Long-term follow-up of three children with early-onset chronic inflammatory demyelinating polyneuropathy is presented. A 3-year-old male (Patient 1) manifested initially progressive muscle weakness during 6 months with spontaneous regression, followed by two severe relapses at 5 and 6 years of age. Decreased arylsulfatase A activity was present in Patient 1 (17.6) and his family members (24.1-40 nmol/mg/hour). Arterial hypertension up to 20/12 kPa was present in two patients in the initial phase associated with muscle stiffness, occasional meningism, and left ventricular hypertrophy in one of them (Patient 3). Subsequently, they both developed two mild relapses at 3.5 and 6 years of age. Clinical outcome was excellent in all three cases, although clinical course, therapy response, and electrophysiologic outcome was quite different in the only patient with low arylsulfatase A activity. The significance of this difference is discussed.

Sensory neuropathy in infantile onset spinocerebellar ataxia (IOSCA)

Infantile onset spinocerebellar ataxia with sensory neuropathy is a new, inherited multisystem disorder discovered in 19 Finnish patients. In order to define the neuropathy of the disease, we measured sensory nerve action potentials and nerve conduction velocities in 18 patients, and recorded somatosensory evoked potentials (SEP) in 10 patients and performed a sural nerve biopsy in 13 patients. The fixed and teased nerve fascicles were examined by light and electron microscopy, and the whole transverse section of a nerve fascicle was photographed and enlarged for morphometric measurements. Our investigation revealed an early onset, rapidly progressive axonal neuropathy: the sensory action potentials were decreased after the age of 2 and a severe loss of mainly large myelinated fibers was found.

Hereditary motor and sensory neuropathy: HMSN type II (neuronal type) and X-linked HMSN

The neuronal forms of hereditary motor and sensory neuropathy (HMSN) are genetically heterogeneous with observed autosomal dominant, autosomal recessive and X-linked dominant inheritance. All three forms are characterized by degeneration of select populations of motor and sensory neurons with accompanying atrophy and degeneration of their axons. Large calibre myelinated fibres are predominantly affected and fibre degeneration and fibre loss progresses from distally to proximally. Attempts of regeneration are noted in all except the severe childhood form. The clinical picture is that of peroneal and distal leg muscle wasting and weakness, distal sensory loss and areflexia. Hand muscles may be severely affected in the autosomal recessive and X-linked dominant forms. Motor and sensory nerve conduction velocities are only moderately slowed and evoked maximum compound motor and sensory amplitudes are reduced according to the degree of fibre loss. The gene locus remains unknown in both the autosomal dominant and autosomal recessive types. For the X-linked dominant HMSN, the gene locus has been mapped closely by linkage analysis to DNA loci in the pericentromeric region of the X-chromosome.

Peripheral sensory-motor polyneuropathy, pigmentary retinopathy, and fatal cardiomyopathy in long-chain 3-hydroxy-acyl-CoA dehydrogenase deficiency

An 11-month-old girl presented acute episodes of hypoglycaemia and hepatic encephalopathy reminiscent of Reye syndrome and 3-hydroxydicarboxylic aciduria. The patient showed peculiar clinical manifestations of severe sensory-motor neuropathy, pigmentary retinopathy, and cardiomyopathy. She died of cardiac failure. Pathological studies of peripheral nerve showed signs of axonal neuropathy and demyelination. Enzymatic studies in cultured fibroblasts showed a deficiency of mitochondrial long-chain 3-hydroxyacyl-CoA-dehydrogenase. Peripheral nerve involvement and retinal pigmentary degeneration have as yet not been described in patients with proven defects of mitochondrial beta-oxidation.