Recurrent Familial Brachial Plexus Palsies as the Only Clinical Expression of ‘Tomaculous’ Neuropathy

Abstract

Two familial cases of recurrent brachial plexus are described and similar episodes were noticed in other members of the family. Electrophysiological investigations found impaired motor and sensory nerve conduction velocity in affected and nonaffected members. Tomaculous neuropathy was found at biopsy of peripheral nerve in more than 40% of dissected fibers. In addition, two affected members showed a reduced interpupillary distance, i.e. the most common dismorphic feature found in the hereditary neuralgic amyotrophy (HNA). A literature review showed only two other instances of recurrent familial brachial plexus palsies as the only manifestation of tomaculous neuropathy (hereditary neuropathy with liability to pressure palsy, HNPP). The dysmorphic feature found in our cases in addition to the clinical, electrophysiological and anatomical data support the hypothesis that these cases of HNPP and the HNA may represent the same disease.

Fulminant case of hereditary neuropathy with liability to pressure palsy

“…7,10 HNA presents as painful episodes of weakness and remarkable muscle wasting, 10 neither of which were observed in our patient. In addition, lower extremity involvement is not a feature of HNA.…”

“…There are rare instances of HNPP presenting as a distal polyneuropathy with a duration in the order of years. 4,10,15,16 The more typical pattern is that of single-nerve involvement resolving in days to months and then followed by a motor deficit in the same or in another distribution. Of the 69 acute nerve palsies that Gouider et al 6 studied in 13 families with documented HNPP, only 4 cases were found that occurred simultaneously in different limbs.…”

Hereditary neuropathy with liability to pressure palsies (HNPP) patients of Korean ancestry with chromosome 17p11.2-p12 deletion

“…In other words, HNPP patients, with congenital abnormalities for compact myelin, easily damage the peripheral nervous system by external compression. Those phenomena differ from both CMT1A and acquired demyelinating neuropathy (Airaksinen et al, 1985;Maritinelli et al, 1989;Uncini et al, 1995).…”

Clinical spectrum of the tomaculous neuropathies. Report of 60 cases and review of the literature

“…It is therefore reasonable to assume that clinical variability is intrinsic to the gene expression. In three cases recurrent attacks of paralyses are restricted to the brachial plexus, thereby suggesting the diagnosis of FBPN [6,5,22]. Data from the literature show that kindreds with inherited plexus neuropathy can be segregated by family into two distinct groups, one characterized by painful plexopathies associated with dysmorphism [33], the other by painless paralysis of the plexus, electromyographic evidence of diffuse sensory and motor neuropathy and tomaculous changes in the peripheral nerve fibers.…”

“…They consisted in slowing of nerve conduction velocity with increased distal latencies and occasional blocks of conduction in nerve trunks, mainly at the level of entrapments. b) 3 unrelated patients with a similar family history had recurrent painless paralyses with attacks restricted to the brachial plexus [22]. These patients had electrophysiological evidence of diffuse sensorimotor neuro~pathy too.…”