The bulbocavernosus reflex (BCR),

bulbospongiosus The bulbospongiosus muscles (in older texts bulbocavernosus and, for female muscle, constrictor cunni) are a subgroup of the superficial muscles of the perineum. They have a slightly different origin, insertion and function in males and females. ...

reflex (BSR) or "Osinski reflex" is a

polysynaptic A reflex arc is a neural pathway that controls a reflex. In vertebrates, most sensory neurons synapse in the spinal cord and the signal then travels through it into the brain. This allows for faster reflex actions to occur by activating spinal mo ...

reflex In biology, a reflex, or reflex action, is an involuntary, unplanned sequence or action and nearly instantaneous response to a stimulus. Reflexes are found with varying levels of complexity in organisms with a nervous system. A reflex occurs ...

that is useful in testing for

spinal shock Spinal shock was first explored by Robert Whytt in 1750 as a loss of sensation accompanied by motor paralysis with initial loss but gradual recovery of reflexes, following a spinal cord injury (SCI) – most often a complete transection. Reflexes ...

and gaining information about the state of

spinal cord injuries A spinal cord injury (SCI) is damage to the spinal cord that causes temporary or permanent changes in its function. It is a destructive neurological and pathological state that causes major motor, sensory and autonomic dysfunctions. Symptoms of ...

(SCI). ''Bulbocavernosus'' is an older term for ''bulbospongiosus'', thus this reflex may also be referred to as the bulbospongiosus reflex.

Procedure

The test involves monitoring

internal Internal may refer to: *Internality as a concept in behavioural economics *Neijia, internal styles of Chinese martial arts *Neigong or "internal skills", a type of exercise in meditation associated with Daoism * ''Internal'' (album) by Safia, 2016 ...

external anal sphincter The external anal sphincter (or sphincter ani externus) is an oval tube of skeletal muscle fibers. Distally, it is adherent to the skin surrounding the margin of the anus. It exhibits a resting state of tonical contraction and also contracts duri ...

contraction in response to squeezing the

glans penis In male human anatomy, the glans penis or penile glans, commonly referred to as the glans, (; from Latin ''glans'' meaning "acorn") is the bulbous structure at the Anatomical terms of location#Proximal and distal, distal end of the human penis ...

clitoris In amniotes, the clitoris ( or ; : clitorises or clitorides) is a female sex organ. In humans, it is the vulva's most erogenous zone, erogenous area and generally the primary anatomical source of female Human sexuality, sexual pleasure. Th ...

, or tugging on an indwelling

Foley catheter In urology, a Foley catheter is one of many types of urinary catheters (UC). The Foley UC was named after Frederic Foley, who produced the original design in 1929. Foleys are indwelling UC, often referred to as an IDCs (sometimes IDUCs). This dif ...

. This reflex can also be tested electrophysiologically, by stimulating the

penis A penis (; : penises or penes) is a sex organ through which male and hermaphrodite animals expel semen during copulation (zoology), copulation, and through which male placental mammals and marsupials also Urination, urinate. The term ''pen ...

vulva In mammals, the vulva (: vulvas or vulvae) comprises mostly external, visible structures of the female sex organ, genitalia leading into the interior of the female reproductive tract. For humans, it includes the mons pubis, labia majora, lab ...

and recording from the anal sphincter. This testing modality is used in

intraoperative The perioperative period is the period of a patient's surgical procedure. It commonly includes ward admission, anesthesia, surgery, and recovery. Perioperative may refer to the three phases of surgery: preoperative, intraoperative, and postoperat ...

neurophysiology monitoring to verify the function of sensory and motor sacral roots as well as the

conus medullaris The conus medullaris (Latin for "medullary cone") or conus terminalis is the tapered, lower end of the spinal cord. It occurs near lumbar vertebral levels 1 (L1) and 2 (L2), occasionally lower. The upper end of the conus medullaris is usually no ...

Trauma

The reflex is spinal mediated and involves S2– S4. The absence of the reflex in a person with acute paralysis from trauma indicates spinal shock whereas the presence of the reflex would indicate spinal cord severance. Typically this is one of the first reflexes to return after spinal shock. Lack of motor and sensory function after the reflex has returned indicates complete SCI. Absence of this reflex in instances where spinal shock is not suspected could indicate a lesion or injury of the

sacral nerve A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body. In the human body there are 31 pairs of spinal nerves, one on each side of the vertebral column. These are grouped into th ...

roots. There is an association between hyperexcitable bulbocavernosus reflex resulting from stimulation of the

prostatic urethra The prostatic urethra, the widest and most dilatable part of the urethra canal, is about 3 cm long. It runs almost vertically through the prostate from its base to its apex, lying nearer its anterior than its posterior surface; the form of ...

and premature ejaculation. The bulbocavernosus reflex has been found to be delayed or absent at a higher rate than the general population in diabetic men with complaints of erectile impotence.

References

{{DEFAULTSORT:Bulbocavernosus Reflex Reflexes