All articles A–Z

Spinach

Spinach (Spinacia oleracea), an Amaranthaceae leafy vegetable domesticated in ancient Persia, spread to 7th-century China and Moorish Spain; dioecious cool-season crop, ~26.7 Mt production, high oxalate, downy mildew breeding.

Spinacia

Spinacia (spinach genus) is a small Amaranthaceae genus, formerly Chenopodiaceae, published by Linnaeus in 1753, native from West and Central Asia to SW Siberia; type species Spinacia oleracea, cultivated spinach.

Spinal anaesthesia

Spinal anaesthesia: injection of local anaesthetic into subarachnoid cerebrospinal fluid to numb the lower body. First performed by August Bier in 1898 with cocaine; commonest complications are postdural puncture headache and hypotension.

Spinal arteriovenous metameric syndrome

Spinal arteriovenous metameric syndrome, also called Cobb syndrome or SAMS 1-31, is a rare non-hereditary disorder with arteriovenous malformations of spinal cord, bone, muscle, and skin in the same metamere, treated by embolization, surgery, steroids, and trametinib.

Spinal cord

Spinal cord: the CNS cylinder of gray and white matter with 31 segments (8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal), ascending sensory and descending motor tracts, reflex function, and regeneration failure after injury.

Spinal cord abscess

Spinal cord abscess: pus collection in or around the spinal cord, usually bacterial (staphylococcus) and often a complication of epidural abscess; rare, treated with surgery and IV antibiotics.

Spinal cord arteriovenous malformation, nidus type

Spinal cord arteriovenous malformation, nidus type (SCAVM, ORPHA:715284): a rare glomerular spinal AVM with an intervening vessel network between artery and vein. Presents younger, with hemorrhage; complete obliteration 27% versus 72% for fistulous type.

Spinal cord injury

Spinal cord injury (SCI): damage to the spinal cord from trauma or disease, causing complete or incomplete loss of movement, sensation, and autonomic function below the injury level; about 15.4 million people affected globally in 2021.

Spinal cord irradiation

Spinal cord irradiation (ICD-11 8E61.1): exposure of the spinal cord to therapeutic ionizing radiation; its main risk is radiation myelopathy, with dose-, fractionation-, and latency-dependent injury and defined tolerance constraints.

Spinal cord segments and vertebral levels

Spinal cord segments and vertebral levels do not align: the adult cord ends at L1–L2, so its 31 nerve segments sit higher than the vertebrae of the same name.

Spinal cord stimulation

Spinal cord stimulation is a neuromodulation therapy in which electrodes implanted in the epidural space deliver electrical pulses to the spinal cord to relieve chronic neuropathic pain.

Spinal cord stimulator

Spinal cord stimulator (SCS): implanted epidural leads plus pulse generator treating chronic neuropathic pain refractory to medical management. Rooted in 1965 gate control theory; first implant 1967, Medtronic system 1968. Complications include infection and lead migration.

Spinal cord stimulator implantation

Spinal cord stimulator implantation is a surgical procedure that places a lead in the epidural space and a pulse generator under the skin to treat chronic neuropathic pain.

Spinal cord traction injury

A spinal cord traction injury is damage to the spinal cord caused by stretching rather than compression, occurring during spinal deformity surgery, delivery, or chronic tethered cord syndrome.

Spinal decompression

Spinal decompression is a family of surgical procedures that relieve pressure on the spinal cord or nerve roots by removing bone, ligament, or disc material.

Spinal deformities

Spinal deformities (ICD-11 FA70) are structural spinal alignment disorders: kyphosis, scoliosis, and lordosis. Key facts include Cobb angle thresholds, AIS prevalence of 1-3%, Hibbs' 1911 first fusion, and Harrington instrumentation.

Spinal dermal sinus

Spinal dermal sinus (dermal sinus tract, congenital spinal dermal sinus): a congenital epithelium-lined tract from the midline skin toward the spine, a closed neural tube defect and occult spinal dysraphism, risking meningitis, abscess, dermoid cysts, and tethered cord.

Spinal epidural arteriovenous malformation

A spinal epidural arteriovenous malformation is a rare vascular lesion in which spinal arteries connect directly to epidural veins, damaging the spinal cord through congestion or compression.

Spinal fixation

Spinal fixation is a surgical procedure that immobilizes segments of the spine with implants such as pedicle screws, rods, and cages to stabilize fractures and correct deformity.

Spinal fMRI

Spinal fMRI is a functional MRI method measuring spinal cord neural activity indirectly through task-evoked BOLD signals, first reported in the human cervical cord in 1996.

Spinal fusion

Spinal fusion, also known as spondylodesis, is surgery that permanently joins two or more vertebrae so no movement occurs between them, most often alongside decompression or diskectomy.

Spinal grey matter

Spinal gray matter is the central, butterfly- or H-shaped region of the spinal cord containing neuronal cell bodies, organized into ten Rexed laminae and surrounded by white matter.

Spinal Infusions

Spinal infusions deliver medication via needle or catheter into the epidural cavity or spinal sac (intrathecal, CSF). Used for labor, surgical, cancer, and chronic pain analgesia and intrathecal baclofen for spasticity, via externalized catheters or implantable pumps.

Spinal Injections

Spinal injections deliver local anesthetic, steroids, or both into epidural, facet, or sacroiliac structures to diagnose or treat spine pain. First used around 1900; 2025 BMJ guideline recommends against most uses for chronic non-cancer spine pain.

Spinal instabilities

Spinal instabilities (ICD-11 FB10): loss of the spine's ability to maintain normal vertebral relationships under load, causing pain or neural risk; causes include trauma, degenerative disease, congenital anomalies, inflammation, and prior surgery; diagnosis remains contested.