The usefulness of minimal F-wave latency and sural/radial amplitude ratio in diabetic polyneuropathy

The possibility of whether minimal F-wave latency and a simple ratio between the sural and superficial radial sensory response amplitudes may provide a useful electrodiagnostic test in diabetic patients was investigated in this report. To evaluate the diagnostic sensitivity of minimal F-wave latency, the Z-scores of the minimal F-wave latency, motor nerve conduction velocity (MCV), amplitude of compound muscle action potentials (CMAP), and distal latency (DL) of the median, ulnar, tibial, and peroneal nerve were compared in 37 diabetic patients. For the median, ulnar, and tibial nerves, the Z scores of the minimal F-wave latency were significantly larger than those of the MCV. In addition for all four motor nerves, the Z scores of the minimal F-wave latency were significantly larger than those for the CMAP amplitude. Furthermore, 19 subjects showing abnormal results in the standard sensory nerve conduction study had a significantly lower sural/radial amplitude ratio (SRAR), and 84% of them had an SRAR of less than 0.5. In conclusion, minimal F-wave latency and the ratio between the amplitudes of the sural and superficial radial sensory nerve action potential are sensitive measures for the detection of nerve pathology and should be considered in electrophysiologic studies of diabetic polyneuropathy.

Electrophysiological findings in newly diagnosed non-insulin-dependent diabetics: a prospective study

This study reports the electrophysiological findings in patients with newly diagnosed non-insulin-dependent diabetes mellitus [NIDDM] studied in the Neurodiagnostic Laboratory of the King Fahd Hospital of the University [KFHU], Al-Khobar, Saudi Arabia. Twenty-nine patients [22 males, 7 females, mean ages 47 and 37 years, respectively] were studied within four weeks of establishing the diagnosis. They were all given nerve conduction studies by the same examiner. Comparison was made with data from a group of 64 normal control subjects. In the study patients, the mean distal sensory peak latency in milliseconds [ms] +/- standard deviation [SD] was 3.5 +/- 0.41 ms in 35 median nerves, 3.2 +/- 0.72 ms in 35 ulnar nerves, 1.9 +/- 0.34 ms in 23 superficial radial nerves and 3.5 +/- 0.61 in 36 sural nerves. The mean distal motor latency +/- SD was 4.6 +/- 0.95 ms in 39 median nerves, 3.5 +/- 0.58 ms in 38 ulnar nerves, 4.8 +/- 1.02 ms in 44 tibial nerves and 6.0 +/- 1.08 ms in 36 peroneal nerves. The electromyogram examination was performed on 24 patients and showed evidence of denervation and/or chronic reinnervation in seven [29%]. The frequency of abnormalities in the studied peripheral nerves was 60% for median, 63% ulnar, 33% peroneal, 16% tibial and 8% sural

Vasculitic neuropathy: profile of twenty patients.

Twenty patients with vasculitic neuropathy were analyzed. Sixteen of the twenty presented with classic mononeuritis multiplex but four had distal, symmetrical, sensorimotor polyneuropathy. Though vasculitic neuropathy is classically associated with Collagen vascular syndromes like, polyarteritis nodosa, rheumatoid arthritis and systemic lupus erythematosis, only 13/20 of our patients had definitive Collagen vascular disease. A large proportion (7/20) had vasculitic neuropathy as the only clinical feature.

Estudo das latências motoras e sensitivas dos nervos cubital, mediano e radial em pacientes com a síndrome do digitador / Study of motor and sensitive latencies of cubital, median and radial nerves in patients with the digitator syndrome

Os autores estudaram 23 pacientes com a síndrome do digitador, sendo sete masculinos e 16 femininos, idade variando de 25 a 42 anos. Foram estudadas as condiçöes nervosas motoras e sensitivas dos nervos mediano, cubital e radial. Os resultados demonstraram lentificaçäo das latências motoras do nervo mediano distal (em cinco pacientes, sendo bilateral em três e unilateral em dois, em um à esquerda e em outro à direita) e proximal (em cinco pacientes, sendo bilateral em três e unilateral em dois, ambos à direita) e da sensitiva distal em um (bilateral). Quando ao nervo cubital, nåo houve alteraçäo da latência motora e distal em nenhum dos pacientes, enquanto que a proximal estava lentificada bilateralmente em dois e apenas à direita em um. A latência sensitiva distal desse nervo estava lentificada em apenas um paciente, à direita. No estudo da latência motora do radial, três apresentaram lentificaçäo bilateral e apenas um à esquerda. Quanto à latência sensitiva distal, havia lentificaçäo unilateral em quatro, três à direita e um à esquerda. A velocidade de conduçäo motora do mediano estava lentificada em três pacientes, dois à direita e um à esquerda. Quanto à velocidade de conduçäo sensitiva, a do mediano estava lentificada em dois pacientes, um à direita e um bilateralmente; a do cubital estava lentificada em um paciente à direita. No que concerne à do radial, havia lentificaçäo em nove pacientes, sendo em quatro bilateral e em cinco, à direita. Verificamos que 15 pacientes apresentaram pelo menos um nervo acometido

Utilidad de los potenciales evocados somato-sensoriales en el diagnóstico del nivel de lesión medular, en pacientes con trauma raqui-medular / The use of somato-sensorial evoked potentials for diagnosis of the level of spinal cord injuries in patients with spine trauma

Se llevó a cabo un estudio comparativo entre dos grupos de 30 individuos cada uno; el primero se integró con pacientes con trauma raqui-medular, 17 con sección completa y 13 incompleta, y el segundo sirvió como grupo controlo, formado por sujetos sanos voluntarios, con el objeto de determinar la utilidad de los potenciales evocados somato-sensoriales (PES). En el caso de los pacientes con trauma raqui-medular, el nervio radial fue el más útil para el diagnóstico cuando el último segmento intacto fue C5. Para el caso de C6, el nervio radial fue útil en el 100 por ciento de los casos y el mediano sólo en el 86 por ciento. En el caso del uso de nervios de las extremidades inferiores, el nervio safeno fue sólo parcialmente útil, ya que registró únicamente un retardo en su latencia en uno de seis pacientes que tenían sección incompleta en el segmento lumbar. No fue útil para evaluar los segmentos cervical y torácico puesto que sus registros fueron negativos en dos pacientes que tenían sección incompleta en el segmento cervical y uno en el torácico. Los PES fueron normales en todos los nervios de los 30 individuos del grupo control.