Sensory Neuropathy With Onion-Bulb Formation

Abstract

A 27-month-old girl suffered from severe sensory neuropathy with minimal motor dysfunction. The CSF protein level was increased and nerve conduction was severely impaired. Sural nerve biopsy specimen showed increased endoneurial connective tissue. An onion-bulb pattern with concentric interdigitations of Schwann cell cytoplasmic processes and redunbant basal laminae were prominent features under electron microscopy. Degress of myelination in individual fiber was far less than expected. Although the clinical manifestations of onion-bulb neuropathy with onset in infancy have been reported to resemble infantile progressive spinal muscular atrophy, the present case demonstrates that the condition can also appear as severe sensory ataxia.

X‐linked motor‐sensory neuropathy type‐II with deafness and mental retardation: A new disorder

“…HMSN types I and I11 may present in infancy, but can be distinguished from the condition present in this family by the presence of slowed motor nerve conduction velocities, usually less than 30 misec. In these latter forms, onion bulb formation is seen on electron microscopic examination of nerve biopsy material [Koto et al, 1978;Dubowitz and Vanesse, 19811. However, the complete absence of onion bulb formation in one of four specimens and a great deal of variability in the amount of remyelination and demyelination has been reported by Van Weerden et a1 119821 in sural nerve biopsies from a family with type I HMSN.…”

X‐linked motor‐sensory neuropathy type‐II with deafness and mental retardation: A new disorder

“…HMSN types I and I11 may present in infancy, but can be distinguished from the condition present in this family by the presence of slowed motor nerve conduction velocities, usually less than 30 misec. In these latter forms, onion bulb formation is seen on electron microscopic examination of nerve biopsy material [Koto et al, 1978;Dubowitz and Vanesse, 19811. However, the complete absence of onion bulb formation in one of four specimens and a great deal of variability in the amount of remyelination and demyelination has been reported by Van Weerden et a1 119821 in sural nerve biopsies from a family with type I HMSN.…”

Infantile Hereditary Neuropathy with Hypomyelination: Report of Two Siblings with Different Expressivity

“…The new form was named "Congenital Hypomyelination Neuropathy" (CHN) and it has been considered to be a separate nosologie entity. So far 29 cases have been reported and congenital impairment in myelin formation has been postulated, in contrast with the classical forms of HMSN which are supposed to be degenerative in origin (1,3,6,8,9,10,11,12,13,14,15,16,17,18,20,21,22,23,24). Different clinical, neurophysiological and morphological features have been indicated as specific for CHN.…”

X‐linked motor‐sensory neuropathy type‐II with deafness and mental retardation: A new disorder

“…HMSN types I and I11 may present in infancy, but can be distinguished from the condition present in this family by the presence of slowed motor nerve conduction velocities, usually less than 30 misec. In these latter forms, onion bulb formation is seen on electron microscopic examination of nerve biopsy material [Koto et al, 1978;Dubowitz and Vanesse, 19811. However, the complete absence of onion bulb formation in one of four specimens and a great deal of variability in the amount of remyelination and demyelination has been reported by Van Weerden et a1 119821 in sural nerve biopsies from a family with type I HMSN.…”

Infantile Hereditary Neuropathy with Hypomyelination: Report of Two Siblings with Different Expressivity

“…The new form was named "Congenital Hypomyelination Neuropathy" (CHN) and it has been considered to be a separate nosologie entity. So far 29 cases have been reported and congenital impairment in myelin formation has been postulated, in contrast with the classical forms of HMSN which are supposed to be degenerative in origin (1,3,6,8,9,10,11,12,13,14,15,16,17,18,20,21,22,23,24). Different clinical, neurophysiological and morphological features have been indicated as specific for CHN.…”

X‐linked motor‐sensory neuropathy type‐II with deafness and mental retardation: A new disorder

“…HMSN types I and I11 may present in infancy, but can be distinguished from the condition present in this family by the presence of slowed motor nerve conduction velocities, usually less than 30 misec. In these latter forms, onion bulb formation is seen on electron microscopic examination of nerve biopsy material [Koto et al, 1978;Dubowitz and Vanesse, 19811. However, the complete absence of onion bulb formation in one of four specimens and a great deal of variability in the amount of remyelination and demyelination has been reported by Van Weerden et a1 119821 in sural nerve biopsies from a family with type I HMSN.…”

Infantile Hereditary Neuropathy with Hypomyelination: Report of Two Siblings with Different Expressivity

“…The new form was named "Congenital Hypomyelination Neuropathy" (CHN) and it has been considered to be a separate nosologie entity. So far 29 cases have been reported and congenital impairment in myelin formation has been postulated, in contrast with the classical forms of HMSN which are supposed to be degenerative in origin (1,3,6,8,9,10,11,12,13,14,15,16,17,18,20,21,22,23,24). Different clinical, neurophysiological and morphological features have been indicated as specific for CHN.…”