What is the place of electroneuromyographic studies in the diagnosis and management of pudendal neuralgia related to entrapment syndrome?

Entrapment of the pudendal nerve may be at the origin of chronic perineal pain. This syndrome must be diagnosed because this can result in the indication of surgical decompression of the entrapped nerve for pain relief. Electroneuromyographic (ENMG) investigation is often performed in this context, based on needle electromyography and the study of sacral reflex and pudendal nerve motor latencies. The limits of ENMG investigation, owing to various pathophysiological and technical considerations, should be known. The employed techniques do not assess directly the pathophysiological mechanisms of pain but rather correlate to structural alterations of the pudendal nerve (demyelination or axonal loss). In addition, only direct or reflex motor innervation is investigated, whereas sensory nerve conduction studies should be more sensitive to detect nerve compression. Finally, ENMG cannot differentiate entrapment from other causes of pudendal nerve lesion (stretch induced by surgical procedures, obstetrical damage, chronic constipation...). Thus, perineal ENMG has a limited sensitivity and specificity in the diagnosis of pudendal nerve entrapment syndrome and does not give direct information about pain mechanisms. Pudendal neuralgia related to nerve entrapment is mainly suspected on specific clinical features and perineal ENMG examination provides additional, but no definitive clues, for the diagnosis or the localization of the site of compression. In fact, the main value of ENMG is to assess objectively pudendal motor innervation when a surgical decompression is considered. Perineal ENMG might predict the outcome of surgery but is of no value for intraoperative monitoring.

Human beta-mannosidase deficiency associated with peripheral neuropathy.

Human beta-mannosidosis is an inherited lysosomal storage disorder described in only seven families. We present a further case in a black African 14-year-old boy with severely deficient beta-mannosidase activity, bilateral thenar and hypothenar amyotrophy, electrophysiologically demonstrable demyelinating peripheral neuropathy, and cytoplasmic vacuolation of skin fibroblasts and lymphoid cells. The clinical and biochemical features of our patient are compared to those of previously reported patients.

Normal CSF levels of met-enkephalin-like material in a case of naloxone-reversible congenital insensitivity to pain.

In a case of naloxone-reversible congenital insensitivity to pain, met-enkephalin-like immunoreactivity in the CSF was in the normal range and not affected by the administration of naloxone. Chromatographic analysis of the met-enkephalin-like material revealed that it corresponded to at least two classes of molecules. A clear difference in the relative proportions of these two classes was detected in the CSF of the patient insensitive to pain when compared to controls. The possible functional significance of this alteration is discussed in relation to the well known antinociceptive action of enkephalins.

[Late ulnar paralysis. Study of a series of 17 cases]. / Les paralysies cubitales tardives. Etude d'une série de dix-sept cas.

Seventeen cases of late ulnar paralysis treated by neurolysis-transposition are reported. The clinical characteristics of these paralyses are emphasized: very prolonged symptom free interval, rapid onset and severe involvement. Ulnar transposition was most often done subcutaneously. Cubitus valgus and definite nerve compression proximal to the arcade of the flexor carpi ulnaris muscle are almost always present. The results as regards the neuropathy are undependable: no patient is completely cured and only half are improved. An anatomical study of the nerve path shows the essential role, in the compression of the nerve, of the muscular arcade of the flexor carpi ulnaris muscle which acts in a way similar to the bridge of a violin. Hence, opening it longitudinally is the principal step of neurolysis. This should be routine before the first signs of neuropathy occur in an elbow whose axis is out of alignment as a sequela of a childhood injury.

Late ulnar paralysis. Study of seventeen cases.

Seventeen cases of late ulnar paralysis treated by neurolysis-transposition are reported. The clinical characteristics of these paralysis are emphasized. A very prolonged symptom free interval, a rapid onset and a severe involvement. The ulnar transposition was most often done subcutaneously. Cubitus valgus and definite nerve compression proximal to the arcade of the flexor carpi ulnaris muscle are almost always present. The results as regards the neuropathy are notable: no patient is completely cured and only half are improved. An anatomical study of the nerve path shows the essential role, in the compression of the nerve, of the muscular arcade of the flexor carpi ulnaris muscle which acts in a way similar to the bridge of a violin. Hence, opening it longitudinally is the principal procedure of the neurolysis. This should be routine before the first signs of neuropathy occur in an elbow whose axis is out of alignment as a sequela of a childhood injury.

[Carpal tunnel syndrome, amyloid tenosynovitis and periodic hemodialysis]. / Syndrome du canal carpien, ténosynovite amyloíde et hémodialyse périodique.

Since 1975, various entrapment neuropathies have been reported in patients undergoing periodic haemodialysis, the most frequent being the carpal tunnel syndrome. Ten patients on chronic haemodialysis developing 15 carpal tunnel syndromes (5 unilateral and 5 bilateral) are reported. Various causes for the renal failure were present and clinical signs of the carpal tunnel syndrome developed at a late stage. The arteriovenous fistula required for extrarenal epuration was antebrachial and of the laterolateral type, except in one case when it was lateroterminal. The carpal tunnel syndrome was always on the same side as the fistula, developing at a later stage on th contralateral side in the 5 cases of bilateral disorders. Lesions were severe, in 11 of the 15 cases. Some patients noted fluctuations in pain symptoms during haemodialysis, either improving or becoming worse. Gross pathological findings during operation (13 cases) were tenosynovitis with epineural hypervascularisation on the opposite side. In 9 cases, however, atypical hypertrophic tenosynovitis was observed. Histological examination in 12 cases demonstrated typical tenosynovitis in 3 patients, but granulomatous tenosynovitis with amyloid deposits was reported in 9 patients. Lesions were bilateral in 2 cases thus present, on the side opposite to the fistula. Ultrastructural study confirmed the amyloid nature of the deposits in 3 cases, the microfibrillary appearance (80 to 100 A) being characteristic of amyloid substance. This rare complication does not represent a common carpal tunnel syndrome, and three mechanisms may be involved in its induction : peripheral uraemic neuropathy, haemodynamic modifications resulting from the antebrachial arteriovenous shunt, and amyloid formation in the flexor synovial sheaths. In the latter case, the type of amyloid disease may be a primary systemic amyloidosis not previously detected, or an elective amyloid process localised to the tenosynovial and periarticular tissues.