25,729 articles
Atypical cystic fibrosis
Atypical cystic fibrosis (non-classic CF), a milder CFTR-mutation disease affecting about 2% of CF patients, with pancreatic sufficiency, borderline sweat chloride, or single-organ disease, often diagnosed in adolescence or adulthood.
Atypical depression
Atypical depression, a major depressive disorder subtype with mood reactivity plus hypersomnia, hyperphagia, leaden paralysis, and rejection sensitivity; MAOI-responsive, immunometabolically distinct from melancholic depression.
Atypical juvenile parkinsonism
Atypical juvenile parkinsonism (ORPHA:391411) is a rare autosomal recessive, complex young-onset Parkinson disease with pyramidal signs, eye movement abnormalities, intellectual disability, ataxia, epilepsy, and psychiatric features, linked to ATP13A2, PLA2G6, FBXO7, DNAJC6, SPG11, SPG15, and SYNJ1.
Atypical lichen myxedematosus
Atypical lichen myxedematosus, an intermediate form of lichen myxedematosus (papular mucinosis), is a rare cutaneous mucinosis not meeting criteria for scleromyxedema or localized LM, with about 20 reported cases and unpredictable course.
Atypical Meigs syndrome
Atypical (incomplete) Meigs syndrome, ORPHA:314466, is a rare benign ovarian tumor disorder with pleural effusion but no ascites; the effusion resolves after tumor resection. Prevalence under 1 in 1,000,000; distinct from pseudo-Meigs and Tjalma syndromes.
Atypical melanocytic naevus
Atypical melanocytic naevus (atypical mole, dysplastic nevus, Clark nevus): a benign acquired mole with melanoma-like clinical features, ICD-11 2F20.1, a strong melanoma risk marker, strongest under age 40.
Atypical papilloma of choroid plexus
Atypical papilloma of choroid plexus (atypical choroid plexus papilloma, aCPP), WHO grade II, ICD-O 9390/1, is a rare intermediate choroid plexus tumor defined by ≥2 mitoses per 10 high-power fields, with higher recurrence risk than grade I papilloma.
Atypical pneumonia
Atypical pneumonia: pneumonia from organisms like Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Legionella, with systemic symptoms, interstitial infiltrates, and beta-lactam resistance; also called walking pneumonia.
Atypical Rett syndrome
Atypical (variant) Rett syndrome: rare genetic neurological disorder requiring regression plus 2 of 4 main and 5 of 11 Rett criteria; linked to MECP2, CDKL5, FOXG1; milder or more severe than classic Rett.
Atypical teratoid rhabdoid tumor
Atypical teratoid rhabdoid tumor (ATRT, AT/RT) is a rare grade 4 embryonal brain or spinal cord cancer of infants and young children, driven by SMARCB1 or SMARCA4 loss, with TYR, SHH, and MYC molecular subgroups.
Atypical Werner syndrome
Atypical Werner syndrome (AWS): clinically diagnosed Werner syndrome without WRN mutations, usually from heterozygous LMNA mutations; autosomal dominant, onset in the early 20s or earlier, faster progression than classical WS, prevalence under 1 in 1,000,000.
Auburn hair
Auburn hair is a reddish-brown human hair color produced by reduced eumelanin with substantial pheomelanin, often linked to one loss-of-function MC1R variant; deeper and browner than copper, darker-red than chestnut.
Audioanalgesia
Audioanalgesia (audio analgesia) is pain control using auditory stimulation such as music, white noise, or environmental sounds; a MeSH-indexed method originating in 1960s dental practice, delivered via patient-controlled earphones.
Audiogenic epilepsy
Audiogenic epilepsy (ORPHA:166415, ICD-11 8A61.40) is a rare reflex epilepsy in which acoustic stimuli, from sudden noises to specific music or voices, trigger seizures; inferior colliculus-driven in rodent models, extremely rare as simple sound-triggered seizures in humans.
Audiologic Recruitment Detection
Audiologic recruitment detection: behavioral and objective tests (ABLB/Fowler, SISI, Metz reflex, category loudness scaling) measuring abnormally rapid loudness growth in cochlear hearing loss.
Audiologists
Audiologists are health care professionals who evaluate, diagnose, and treat hearing loss, balance disorders, and tinnitus in all ages, typically holding a doctor of audiology degree.
Audiology
Audiology: healthcare profession of hearing and balance care; audiologists diagnose and treat hearing, balance, tinnitus, and auditory disorders across all ages; doctoral (Au.D.) trained; shaped by the 2022 FDA OTC hearing aid category.
Auditory Brain Stem Implantation
Auditory brainstem implantation (ABI) places an electrode array on the cochlear nucleus to give sound perception to people deaf from NF2, cochlear nerve aplasia, or cochlear ossification who cannot use cochlear implants; first implanted 1979, over 1,000 procedures worldwide.
Auditory Brain Stem Implants
Auditory brainstem implant (ABI), a neuroprosthesis stimulating the cochlear nucleus for deafness when the cochlear nerve or cochlea is unusable, originally for neurofibromatosis type 2; FDA approved 2000.
Auditory brainstem response
The auditory brainstem response (ABR), also called BAER, is an electrophysiological test recording auditory nerve and brainstem activity, used to estimate hearing thresholds in infants and assess brainstem function.
Auditory cortex
The auditory cortex is the region of the temporal lobe that receives and processes sound information from the ears, with primary area A1 on Heschl's gyrus.
Auditory Evoked Potentials
Auditory evoked potentials (AEPs) are scalp-recorded EEG responses to sound, spanning the ABR (under 10 ms), middle latency responses, cortical CAEPs, and sustained ASSR/FFR; used for objective hearing threshold estimation, screening, and hearing aid and cochlear implant assessment.
Auditory fatigue
Auditory fatigue is a temporary loss of hearing sensitivity after sound exposure, measured as a temporary threshold shift in decibels that recovers over minutes to days.
Auditory hallucination
Auditory hallucination: hearing sounds or voices without external stimulus; verbal subtype (AVH) affects 60-80% of schizophrenia patients and 10-15% of healthy people; explained by corollary discharge failure and inner-speech misattribution.
Auditory processing disorder
Auditory processing disorder, also called central auditory processing disorder, is a neurological disorder in which the brain has trouble processing sounds even though hearing sensitivity is normal.
Auditory scene analysis
Auditory scene analysis is the framework describing how listeners group a sound mixture into separate auditory streams, established in Albert Bregman's 1990 monograph and the basis of computational sound-separation systems.
Auditory steady-state response
The auditory steady-state response (ASSR), also known as the steady-state evoked potential or amplitude-modulation following response, is an electrophysiological test that objectively estimates hearing thresholds in sleeping or sedated infants.
Auditory-verbal therapy
Auditory-verbal therapy (AVT) is a parent-coached early-intervention therapy that teaches children with hearing loss to develop listening and spoken language through hearing aids or cochlear implants, without lipreading.
Augmentation mastopexy
Augmentation mastopexy is a combined breast operation that places an implant while lifting and reshaping a sagging breast, used when neither augmentation nor mastopexy alone suffices.
Augmentation rhinoplasty
Augmentation rhinoplasty is a surgical procedure that adds grafts or implants to the nose to increase dorsal height or tip projection, often to correct a saddle nose deformity.