Human health and medicine

Lobotomy

Lobotomy (leucotomy), a discredited psychosurgical procedure severing prefrontal-thalamic connections, introduced by Egas Moniz in 1935, Nobel-recognized 1949, popularized by Walter Freeman's transorbital method, abandoned after antipsychotics emerged in the 1950s.

Lobulated kidney

Lobulated kidney, or persistent fetal lobulation (renculation), is a benign anatomical variant where fetal renal lobules fail to fuse fully, leaving surface indentations between pyramids; found in about 10% of adults, it mimics tumors or scars on ultrasound but enhances like normal parenchyma on CT and MRI.

Local anesthesia

Local anesthesia: numbing a limited body area with sodium-channel-blocking drugs while the patient stays conscious. From cocaine (Koller, 1884) and Bier's 1898 spinal to lidocaine, bupivacaine, LAST management, and local-versus-general outcome comparisons.

Local anesthetic

Local anesthetic: drugs (cocaine, lidocaine, bupivacaine, ropivacaine) that reversibly block voltage-gated sodium channels to numb a body region; ester vs amide classes, differential block, LAST toxicity and lipid emulsion treatment.

Local corticosteroid injection

Local corticosteroid injection delivers a corticosteroid, usually with a local anesthetic, directly into an affected joint, tendon sheath, bursa, or epidural space to reduce local inflammation and pain.

Local Field Potential Measurement

Local field potential (LFP) measurement records low-frequency extracellular brain voltage, below about 300 Hz, from intracerebral microelectrodes; also called micro- or depth EEG. It reflects summed synaptic currents of neuronal populations and is used in adaptive deep brain stimulation.

Local interneuron

Local interneuron (local circuit neuron): a neuron with a locally confined axon; in cortex, GABAergic cells (~20-30% of neurons) in PV, SST, and 5HT3aR classes, born in ganglionic eminences, linked to epilepsy, schizophrenia, autism.

Local lymph node assay

The local lymph node assay (LLNA) is a mouse-based skin-sensitization test that identifies contact allergens and estimates their potency from lymphocyte proliferation in lymph nodes draining the ear, standardized as OECD Test Guideline 429 in 2002.

Local radiotherapy

Local radiotherapy delivers ionizing radiation to a localized tumor or body region to destroy malignant cells while sparing healthy tissue, typically in daily 2 Gy fractions over several weeks.

Localised abdominal pain

Localised abdominal pain (localized abdominal pain), ICD-11 MD81.1, SNOMED CT 102613000: pain confined to one area of the belly, suggesting a single-organ cause such as appendicitis, cholecystitis, or diverticulitis rather than generalized pain.

Localised adiposity

Localised adiposity (限局性脂肪症), ICD-11 5B80.1 / ICD-10 E65: focal accumulation of normal adipose tissue in specific body regions, independent of BMI; distinct from generalized obesity and lipoma; synonyms include fat pad.

Localised oedema

Localised oedema (localized edema), ICD-11 MG29.0, is excess interstitial fluid at a specific anatomic site, caused by trauma, infection, venous or lymphatic obstruction, distinguishing it from generalized anasarca.

Localized epidermolysis bullosa simplex

Localized epidermolysis bullosa simplex (EBS-loc, formerly Weber-Cockayne) is the mildest, most common EBS subtype (about 60% of cases), an autosomal dominant KRT5/KRT14 disorder causing palmoplantar blisters triggered by friction and heat, treated supportively.

Localized intravascular coagulation

Localized intravascular coagulation (LIC), also called localized intravascular coagulopathy, is a consumptive coagulopathy confined to a vascular lesion, occurring chiefly in venous malformations and marked by elevated D-dimer.

Localized junctional epidermolysis bullosa

Localized junctional epidermolysis bullosa is a mild subtype of junctional epidermolysis bullosa, an inherited blistering skin disease present from birth and confined mainly to the hands, feet, and face.

Localized pagetoid reticulosis

Localized pagetoid reticulosis, or Woringer-Kolopp disease, is a rare indolent variant of mycosis fungoides: a solitary hyperkeratotic or psoriasiform plaque, usually on one extremity, treated with radiotherapy or excision, with no reported disease-related deaths.

LOCATION trial

LOCATION trial (NCT07388030), a 2x2 factorial randomized trial in China comparing intravascular lithotripsy versus balloon angioplasty and OCT- versus angiography-guided stenting in 3,060 patients with severely calcified coronary lesions; primary endpoint 3-year target vessel failure.

Lochia

Lochia is the normal postpartum vaginal discharge of blood, mucus, and uterine tissue after childbirth, lasting about 2 to 8 weeks, changing from red to pink to whitish, and distinct from menstruation.

Locked-in syndrome

Locked-in syndrome (LIS): rare neurological state of quadriplegia, anarthria, and lower cranial nerve paralysis with fully preserved consciousness, usually from ventral pons stroke; communication via eye movements, eye trackers, or BCIs.

Locking plate fixation

Locking plate fixation, also called volar locking plate fixation, is a surgical technique in which screw heads thread into the plate, forming a fixed-angle construct that stabilizes fractures.

Locum

Locum, from Latin locum tenens ("holding the place"), is a person, usually a physician or cleric, substituting temporarily for another; a $9.4 billion US medical staffing sector covering rural and short-staffed facilities.

Locus of control

Locus of control, proposed by Julian Rotter in 1954, is the belief about whether life outcomes stem from one's own actions (internal) or external forces like luck or others (external), measured by scales such as Rotter's I-E and Levenson's I-P-C.

Lodoxamide

Lodoxamide (lodoxamide tromethamine, Alomide) is a 0.1% topical ophthalmic mast cell stabilizer, dosed four times daily, for allergic conjunctivitis and vernal keratoconjunctivitis; not FDA-approved for long-term use.

Loeffler endocarditis

Loeffler endocarditis, also called eosinophilic endomyocardial disease, is a rare restrictive cardiomyopathy from eosinophil-mediated heart damage in hypereosinophilic syndrome, progressing through necrotic, thrombotic, and fibrotic stages.

Loeys–Dietz syndrome

Loeys–Dietz syndrome (LDS), or Loeys-Dietz aortic aneurysm syndrome, is an autosomal dominant connective tissue disorder caused by TGF-beta pathway gene variants (TGFBR1/2, SMAD2/3, TGFB2/3, IPO8), marked by aggressive aortic and arterial aneurysms, craniofacial and skeletal features, and allergic disease.

Lofepramine

Lofepramine (Gamanil) is a tricyclic antidepressant, an imipramine analogue metabolized to desipramine, ATC N06AA07, with efficacy comparable to other TCAs, fewer anticholinergic side effects, and relative safety in overdose.

Lofexidine

Lofexidine (Lucemyra) is a central alpha-2 adrenergic agonist, the first FDA-approved non-opioid treatment (May 2018) for mitigating opioid withdrawal symptoms in adults during abrupt opioid discontinuation.

LogMAR chart

LogMAR chart: eye chart with logarithmic letter-size progression, 5 letters per line, and letter-by-letter scoring, from Bailey–Lovie (1976) and the ETDRS chart (1982), the clinical-trial standard for visual acuity.

Logopenic progressive aphasia

Logopenic progressive aphasia (LPA, lvPPA) is a variant of primary progressive aphasia marked by word-finding difficulty and impaired sentence repetition with spared single-word comprehension, usually linked to Alzheimer disease and left temporoparietal atrophy.