Meralgia paresthetica: electrophysiologic study

Conduction velocity of the lateral femoral cutaneous nerve was studied orthodromically. The mean value in 20 control subjects was 57.51 +/- 8.61 (SD) m/sec. In 9 patients with meralgia paresthetica, the sensory nerve condition in the symptomatic nerves was definitely abnormal: nerve potential was absent in 6 and condition velocity was slow in 3. In 1 patient, a possible asymptomatic entrapment neuropathy was suggested by this test. Conduction velocity of the lateral femoral cutaneous nerve can be used as an objective diagnostic aid in meralgia paresthetica.

[Haemophilic pseudo-tumours and iliac haematomas: radiological and clinical findings (author's transl)]

Between 1971 and 1977, 648 patients with haemophilia were seen; of these 38 had pseudo-tumours and 163 iliac haematomas. Amongst the latter 153 were cured by the administration of the appropriate factor. In ten the symptoms persisted. In the early stages the diagnosis cannot be made radiologically. Large haematomas produce indirect evidence of their presence by displacing the bladder. Particularly with small haematomas, computer tomography has proved a reliable and accurate diagnostic measure. Without treatment, a haemophilic pseudo-tumour may develop. Its radiological differential diagnosis includes malignant and benign bone tumours, inflammatory and parasitic disease. Therapy includes conservative measures (factor concentrates) or operative intervention (removal of the haematoma).

Why can't you achieve adequate regional anesthesia in the presence of infection?

Observed in this study were morphologic changes in inflamed nerves, along with biochemical changes, which appear to act concurrently to deactivate or prevent activation of the local anesthetic solution. Morphologic changes were observed along the nerve fiber distant from the inflammatory site. These neuro-degenerative changes were seen at the axon and myelin sheaths level. The biochemical data support the presence in the inflamed nerve of amino acids which may be the product of lysosomal rupture and proteolytic enzyme release. These inflammatory mediators may affect either the local anesthetic or the environment of the nerve fiber. The precise mechanism of action of these catalytic products cannot be determined from this study.

Sensory nerve conduction in the upper limbs at various stages of diabetic neuropathy

In 59 diabetic patients, sensory nerve potentials were recorded at various sites along the course of the median nerve. Pathological responses were characterized by reduced amplitude, desynchronization and decreased conduction velocity (CV). Four groups of patients with increasingly severe nerve dysfunction were distinguished. The presence and severity of clinical neuropathy in the upper limbs could be related to decreased maximal sensory nerve CV in the proximal segment of the limbs. When maximal sensory nerve CV was normal above the wrist, neuropathy usually remained latent. In severe cases where no sensory nerve potentials could be recorded, the cerebral evoked potentials nonetheless permitted a precise evaluation of the somatosensory conduction. In these cases, maximal sensory nerve CV was very low. In five patients with a so-called diabetic mononeuropathy, abnormal nerve potentials were recorded in the median nerve, although no clinical signs could be seen in the corresponding territory. It is proposed that the diabetic nature of a mononeuropathy can be assessed by the finding of latent abnormalities in seemingly normal nerve.