Heredofamilial Brachial Plexus Neuropathy (Hereditary Neuralgic Amyotrophy with Brachial Predilection) in Childhood

Abstract

SUMMARY Three families with a total of at least 12 members affected by heredo‐familial brachial plexus neuropathy (hereditary neuralgic amyotrophy) are described, and three affected boys (age‐range 4 to 7 years 10 months) are reported in detail. All three children had recurrent episodes of pain in the shoulders and arms, followed by weakness and wasting of affected muscles. Subsequently there was gradual recovery. All three had close‐set eyes, and affected relatives usually had a similar physiognomy. Case 1 had had an inappropriately low birthweight, and his affected mother was significantly small (154cm). The other two boys were of borderline low‐normal stature. Case 2 required plication of his left hemi‐diaphragm at the early age of seven weeks, probably because of left phrenic paralysis. He also had a cleft palate. In all three families the condition appeared to be inherited through an autosomal dominant gene. Electrodiagnostic studies were performed, and Case 3 was tested repeatedly. Conduction velocity in motor fibres of the median, ulnar and lateral popliteal nerves was normal or slightly low, often with low amplitude of evoked muscle‐action potentials. The sensory action potentials in median and radial nerves were of abnormally low amplitude in acutely involved arms. Electromyography showed evidence of denervation in the acutely weak muscles in some patients, and indications of neurogenic atrophy were present in all and extended to leg muscles in two of the three probands, thus demonstrating the widespread distribution of the disorder. The clinical features, differential diagnosis, electrodiagnostic findings, possible location of the neuropathy, and management are discussed. While present data are consistent with the concept of ‘mononeuritis multiplex’ and a genetic predisposition, the exact site of the lesion will have to be determined by proximal‐nerve conduction studies through the brachial plexus in the acute phase of the disease, in addition to the routine investigations reported to date. Meanwhile it is suggested that the more non‐committal term ‘hereditary neuralgic amyotrophy with brachial predilection’ be used for the disease. RESUME Neuropathie hérédo‐familiale du plexus brachial dans l'enfance (amyotrophie névralgique héréditaire à prédilection brachiale) Trois familles regroupant au moins 12 membres atteints d'une neuropathie hérédo‐familiale du plexus brachial (amyotrophie névralgique héréditaire) sont étudiées et trois garçons atteints (âgés de quatre à sept ans dix mois) sont analysés plus en détail. Ces trois enfants avaient présenté des épisodes répétés de douleur dans les épaules et les bras, suivis de faiblesse et atrophie des muscles atteints. Par la suite, il y eut une récupération progressive. Dans les trois cas, on notait des yeux à demi fermés et habituellement les parents atteints avaient la même physionomie. Le cas 1 avait eu un poids de naissance faible pour le terme et sa mère atteinte était significativement petite (154cm). Les deux autres garçons de la fratrie étaient d'une ta...

Recurrent brachial plexus neuropathy in a family with subtle dysmorphic features‐a case of hereditary neuralgic amyotrophy

“…The dysmorphic features of our patients were only slight. However, they had a narrow face and hypotelorism and did indeed show the resemblance to portraits by Modigliani pointed out by Dunn et al (1978).…”

“…The hereditary form has a greater tendency to start in childhood (Dunn et al 1978), although both HNA and the sporadic form most commonly occur in the third and fourth decade (Windebank 1984). Patient 1 had his first attack when he was 15 years old.…”

“…Hereditary neuralgic amyotrophy (HNA) or familial brachial plexus neuropathy was first described as rheumatic peripheral neuritis (Dreschfeldt 1886). Since then there have been nearly 100 reported cases with this disorder (Taylor 1960, Dunn et al 1978, Airaksinen et al 1985. The typical features are onset of pain followed by weakness of one or both upper limbs in the second or third decade.…”

Neuralgic amyotrophy: An update on diagnosis, pathophysiology, and treatment

“…NA is more common in men than in women, occurring in a ratio of about 2:1, and it can affect people of all ages, with a median onset age of around 40 years for the idiopathic form and around 25 years for the hereditary form . Several reports have described the disorder in children and newborns, with the latter often seeming to show an association with a concomitant osteomyelitis of the humerus …”

“…4 Several reports have described the disorder in children and newborns, with the latter often seeming to show an association with a concomitant osteomyelitis of the humerus. [16][17][18][19][20] Recurrent episodes occur in a significant proportion of patients, with at least 25% of idiopathic cases and 75% of hereditary cases having a second episode during the first years after their initial attack. 4 In our clinical practice, over the last 20 years, we found that recurrences occur even more often, and they seem to be a common feature of the disorder.…”