Hereditary motor and sensory neuropathy with deafness, mental retardation, and absence of sensory large myelinated fibers: confirmation of a new entity.

We describe two brothers, 11 and 13 years old, respectively, with an early-onset hereditary motor and sensory neuropathy, deafness, and mental retardation. Electrophysiological studies showed marked reduction of motor and sensory conduction velocity and absence of sensory action potentials. Sural nerve biopsy, performed in both patients, showed absence of large myelinated fibers with normal density of small myelinated fibers without axonal degeneration. Signs of demyelination were found only in the younger patient. We suggest that motorsensory neuropathy associated with deafness and mental retardation with absence of large myelinated fibers on sural nerve biopsy represents a distinct clinicopathological entity, which is transmitted in families probably as an autosomal recessive trait.

Pure motor chronic inflammatory demyelinating polyneuropathy.

We describe four patients affected by chronic inflammatory demyelinating polyneuropathy (CIDP) in a pure motor form. Selective involvement of motor fibers was suggested by the absence of sensory symptoms, normal sensation at neurological examination and normal findings on electrophysiological testing of sensory fibres and sural nerve biopsy. The onset of the disease occurred at a young age (3-29 years) and the clinical course was relapsing-remitting. Over a follow-up period of 1.5-14 years, periodical clinical and electrophysiological examinations showed that selective involvement of motor fibers remained a constant feature. Electromyography and nerve conduction studies continued to show a purely demyelinating neuropathy without signs of axonal impairment. All patients were steroid-unresponsive, whereas they considerably improved after being treated with immunoglobulins. Two patients were treated with interferon alpha and showed a good response. In conclusion, the occurrence in our four patients of pure motor involvement over a long period of time during which several relapses occurred, suggests that pure motor CIDP may represent the result of a specific immunological process rather than of a random distribution of inflammation throughout peripheral nerves.

Familial spastic paraplegia, axonal sensory-motor polyneuropathy and bulbar amyotrophy with facial dysmorphia: new cases of Troyer-like syndrome.

We studied two Libyan siblings, born to healthy consanguineous parents, who had suffered from a progressive neurological disorder, characterized by facial dysmorphia, ataxia, spastic paraplegia and an axonal sensory-motor polyneuropathy, since the age of 3 years. The clinical picture progressed slowly over a 6-year period to involve also bulbar and distal limb muscles. Interestingly, we found unusual tubulofilamentous inclusions in peripheral nerves and presynaptic buttons at the neuromuscular junctions. Describing the clinical picture of this presumably new disorder, we comment on the difference from similar conditions.

Intramyelinic edema in chronic inflammatory demyelinating polyneuropathy.

We describe a patient affected by chronic inflammatory demyelinating polyneuropathy (CIDP) whose sural nerve biopsy revealed a marked edema of the myelin sheath. Since this change has been previously described in human peripheral nerves only in CIDP patients, we suggest that intramyelinic edema may have a role in the pathogenesis of demyelinating neuropathies.

Gliomatosis cerebri: report of an atypical case.

Gliomatosis cerebri (GC) is a rare, diffusely infiltrating tumor of neuroepithelial origin. The clinical diagnosis is difficult since GC is a diffuse and progressive disease of the central nervous system (CNS). Non-specific findings can be detected by computed tomography (CT) whereas, according to some authors, the extent of this tumor can be accurately depicted by magnetic resonance imaging (MRI). In this paper the neuroradiologic, neuropathologic and immunohistochemical features in a further case of GC are reported.

Acute axonal idiopathic polyneuropathy: a Guillain-Barré syndrome variant?

We report 7 cases of acute polyneuropathy fitting the NINDS diagnostic criteria for GBS. Electrophysiological study and sural nerve biopsy revealed a picture of axonal polyneuropathy, without changes suggesting demyelination. We discuss whether the acute idiopathic axonal neuropathy belongs to the GBS spectrum or represents a separate clinico-pathological entity.

Chronic progressive steroid responsive axonal polyneuropathy: a CIDP vaariant or a primary axonal disorder?

Five patients presented with chronic,, progressive, predominantly motor polyneuropathy. CSF protein content was increased in 4 patients. Motor conduction velocities and EMG were consistent with axonal involvement. Sural nerve conductions were normal in all cases and sural nerve biopsy performed in 1 patient was normal. Serum antibodies to GM1, GD1a, GD1b, and GM2 were negative. All patients improved after steroid treatment and 3 completely recovered. Because of therapeutic implications it is important to differentiate these patients from those with chronic idiopathic axonal neuropathies. It is unclear whether this is a primary axonal, probably immune-mediated, polyneuropathy, or whether it represents one extreme of the chronic inflammatory demyelinating polyradiculoneuropathy spectrum characterized by severe axonal loss. We suggest that the term "chronic inflammatory polyneuropathy," encompassing cases from pure demyelinating to pure axonal neuropathies responsive to steroids, should be reinstated and that, like in Guillain-Barré syndrome, different subtypes should be individuated.

Differential electrophysiological features of neuropathies associated with 17p11.2 deletion and duplication.

UNLABELLED: Hereditary neuropathy with liability to pressure palsies (HNPP) and hereditary motor-sensory neuropathy type IA (HMSN IA) are quite distinct clinical entities recently associated to deletion and duplication, respectively, of the 17p11.2 segment including the gene for peripheral myelin protein 22 (PMP-22). We studied the electrophysiological features of 48 HNPP and 62 HMSN IA motor nerves. Conduction velocities (CV) and compound muscle action potential amplitudes were significantly reduced and distal latencies prolonged in HMSN IA compared to HNPP. CV was uniformly slowed in HMSN IA nerves whereas in HNPP it was focally slowed in 80% of ulnar and 12% of peroneal nerves at usual compression sites. Conduction block was present in 6% of HNPP nerves but in none of HMSN IA. IN CONCLUSION: (1) HMSN IA with 17p11.2 duplication presents marked, diffuse, and uniform slowing; (2) HNPP with 17p11.2 deletion presents focal electrophysiological abnormalities possibly correlated with the presence of tomaculae; and (3) under- and overexpression of PMP-22 in concurrence with environmental factors might be responsible for the distinctive features of HNPP and HMSN IA.

Autosomal recessive hypermyelinating neuropathy.

We studied three patients from two kinships, affected by early onset hereditary motor and sensory neuropathy with probable autosomal recessive inheritance (HMSN type III). Morphological studies of sural nerve biopsies revealed an abnormal myelin proliferation. Two adult patients with long-term follow up, lost ability to walk at 28 and 22 years and showed severe involvement of the cranial nerves. Our observations suggest that "hypermyelination neuropathy" with early onset is a progressive disease with poor long-term prognosis. In one kinship the occurrence of the disease in two sibs of both sexes but not in parents, is consistent with an autosomal recessive inheritance. Familial cases of hypermyelination neuropathy have not been described in previous reports. Morphological aspects of this condition are compared with other forms of hypermyelination neuropathy.