The cremasteric reflex and its muscle – a paragon of ongoing scientific discussion: A systematic review

Abstract

The technique of triggering the cremasteric reflex and its respective signaling pathway is not described uniformly throughout the literature. As this reflex is a useful sign in diagnosing testicular torsion, orchitis, varicocele, and undescended testis, it seems desirable to identify and define the correct mechanism. Our aim was to investigate how the cremasteric reflex and its signaling pathway are described in the current literature and how the variability of the innervation of the inguinal region could affect the frequency of this reflex. Thirty-five original articles and 18 current textbooks were included after searching PubMed (MEDLINE) and Scopus for the terms "cremaster muscle," "cremasteric reflex," and "genitofemoral nerve" and after applying all exclusion criteria. This systematic review was performed according to the PRISMA Statement Rules. Eliciting the cremasteric reflex was defined either as "rubbing of the upper inner thigh" or "rubbing of the skin under the inguinal ligament." Four different afferent pathways among studies and three different pathways among textbooks were described and the frequency of an intact reflex ranged between 42.7 and 92.5% in newborns and between 61.7 and 100% in boys between 24 months and 12 years. Owing to the huge differences among the studies investigated and the lack of convincing results, it is not possible to define the correct way to elicit the cremasteric reflex. Four hypotheses about the afferent pathway are proposed on the basis of the literature. Further studies should be performed, concentrating on the afferent pathway(s) with respect to the individual innervation of the inguinal region. Clin. Anat. 30:498-507, 2017. © 2017 Wiley Periodicals, Inc.

Intraoperative Nerve Stimulation as an Approach for the Surgical Treatment of Genitofemoral Neuralgia

“…The femoral branch travels under the inguinal ligament in the femoral canal to provide sensory innervation to the skin of the upper, anterior, and medial aspect of the thigh. Both of these branches are important for the cremasteric reflex; although the specifics are disputed, many agree that the femoral branch provides the afferent pathway and the genital branch provides the efferent pathway [ 11 ]. Others posit that the ilioinguinal nerve serves the afferent pathway.…”

Ossification of the ligamentum flavum in the thoracic spine mimicking sciatica in a young baseball pitcher:a case report

“…In our case, loss of left cremaster reflex, posterior hamstring tightness, and increased deep tendon reflexes of the ipsilateral lower extremities were the only abnormal findings which led to suspicion of upper neuron disturbance at the L1 to L2 spinal cord segments. The cremasteric reflex is generally maintained in healthy young adults 25,26) . Radiographic assessment of the thoracolumbar junction is also important.…”

Revisiting the genital and femoral branches of the genitofemoral nerve: Suggestion for a more accurate terminology

“…In these cases, other adjacent nerves such as the ilioinguinal or femoral nerves might overlap and compensate for the absent branch (Rab et al, ). Therefore, knowledge of anatomical variations of the lumbosacral plexus might avoid iatrogenic complicatons and aid in understanding non standard clinical examinations (Schwarz and Hirtler, ; Mahan et al, ; Iwanaga et al, , ).…”