Nervous and sensory conditions

Usher syndrome

Usher syndrome, also called Usher's syndrome or deafness-retinitis pigmentosa syndrome, is an autosomal recessive condition combining sensorineural hearing loss and retinitis pigmentosa; three types, about 4-17 per 100,000 people, no cure yet.

Variably protease-sensitive prionopathy

Variably protease-sensitive prionopathy (VPSPr), formerly PSPr, is a rare sporadic human prion disease identified in 2008, with protease-sensitive abnormal prion protein, onset near age 70, and no PRNP mutation.

Varicella encephalitis

Varicella encephalitis is brain inflammation from varicella zoster virus, complicating chickenpox or viral reactivation. It affects 1–2 per 10,000 varicella cases, is treated with acyclovir, and has 5–20% mortality.

Vascular abnormalities of conjunctiva

Vascular abnormalities of conjunctiva (ICD-11 9A61.40, ICD-10 H11.41): abnormalities of conjunctival blood vessels, including telangiectasia, lymphangiectasia, malformations, and vascular tumors, often signaling systemic disease.

Vascular parkinsonism

Vascular parkinsonism (VP, VaP; ICD-11 8A00.23), also called lower body or arteriosclerotic parkinsonism, is secondary parkinsonism from cerebrovascular disease: gait-predominant, tremor-poor, levodopa-poor response, abnormal MRI, preserved DAT-SPECT.

Venezuelan equine encephalitis

Venezuelan equine encephalitis (VEE), caused by VEEV, a mosquito-borne alphavirus endemic to the Americas; epizootic IAB/IC strains amplify in equids, driving outbreaks such as 1969–1972 and 1995; humans usually get self-limited fever, supportive care only.

Vertical gaze palsy

Vertical gaze palsy (VGP), also called supranuclear vertical gaze palsy, is conjugate bilateral limitation of upgaze and/or downgaze from midbrain lesions involving the riMLF, INC, or posterior commissure; chronic cases are usually progressive supranuclear palsy, acute ones infarction.

Vertiginous syndromes

Vertiginous syndromes are grouped vestibular symptom sets (vertigo, dizziness, imbalance) classified by the Bárány Society ICVD as acute, episodic, or chronic, spanning peripheral disorders like BPPV, Ménière's disease, and vestibular neuritis and central causes like stroke, with ICD-10 code H82.

Vertigo of central origin

Vertigo of central origin (ICD-11 MB48.00) is spinning hallucination from brainstem, cerebellar, or vestibular nucleus lesions, most often ischemic stroke; distinguished from peripheral vertigo by HINTS exam, nystagmus type, and MRI.

Vestibular nystagmus

Vestibular nystagmus (ICD-11 9C84.2) is involuntary rhythmic eye movement from vestibular imbalance; peripheral forms are unidirectional and fixation-suppressed, central forms vertical, torsional, or direction-changing, assessed by HINTS.

Vestibular paroxysmia

Vestibular paroxysmia is a rare vestibular disorder in which short attacks of vertigo, up to 30 or more per day, are attributed to neurovascular compression of the eighth cranial nerve.

Viral meningitis

Viral meningitis, also called aseptic meningitis, is inflammation of the brain and spinal cord lining caused by viruses, most often non-polio enteroviruses. Most cases recover within 7 to 10 days; mortality is far lower than bacterial meningitis.

Visual agnosia

Visual agnosia: inability to recognize visually presented objects despite normal vision, language, and memory, with intact recognition by touch. Subtypes are apperceptive and associative (Lissauer 1890, Seelenblindheit), plus category-selective forms like prosopagnosia.

Visual deprivation nystagmus

Visual deprivation nystagmus, also called amaurotic or ocular nystagmus, is involuntary eye movement caused by binocular visual loss, typically infantile cataract during the sensitive period; ICD-11 code 9C84.50.

Visual discomfort

Visual discomfort (asthenopia, eye strain; ICD-11 9D50) is pain or discomfort in or around the eyes with headache and nausea, triggered by stripes, flicker, and glare, linked to excessive visual cortex activity.

Visual floaters

Visual floaters (vitreous floaters, myodesopsia) are shadows on the retina cast by clumps in the eye's vitreous gel, usually from age-related posterior vitreous detachment; sudden new floaters with flashes can signal retinal tear or detachment.

Visual hallucinations

Visual hallucinations are the perception of objects or events in the absence of an external stimulus, occurring in eye disease, neurologic disorders, toxic states, and psychiatric illness.

Visual impairment

Vision impairment including blindness (ICD-11 9D90) is reduced vision from eye conditions, graded by visual acuity. At least 2.2 billion people affected; leading causes are refractive error and cataract.

Visual release hallucinations

Visual release hallucinations, or Charles Bonnet syndrome, are complex purely visual hallucinations in people with vision loss and intact cognition, caused by cortical release after deafferentation, often ceasing when sight improves.

Visual snow syndrome

Visual snow syndrome (VSS), also called visual snow, is a chronic neurological condition of continuous pan-field visual static plus palinopsia, entoptic phenomena, photophobia, or nyctalopia; ICHD-3 criteria, ~2% prevalence, cortical hyperexcitability, and lamotrigine as best-evidence treatment distinguish it.

Vitreous haemorrhage

Vitreous hemorrhage is bleeding into the vitreous cavity of the eye, causing sudden painless vision loss; common causes include diabetic retinopathy, posterior vitreous detachment, and trauma.

Vogt-Koyanagi-Harada disease

Vogt-Koyanagi-Harada syndrome (フォークト・小柳・原田症候群), also called VKH disease or uveomeningoencephalitic syndrome, is a bilateral granulomatous autoimmune panuveitis targeting melanocyte-rich tissues, with HLA-DRB1*0405 association, staged course, and corticosteroid plus immunomodulatory treatment.

Von Hippel–Lindau disease

Von Hippel–Lindau disease (VHL), an autosomal-dominant VHL tumor-suppressor gene cancer syndrome causing hemangioblastomas, renal cell carcinoma, pheochromocytoma, and pancreatic tumors; treated with surveillance and the HIF-2α inhibitor belzutifan.

WAC-related facial dysmorphism-developmental delay-behavioral abnormalities syndrome

WAC-related facial dysmorphism-developmental delay-behavioral abnormalities syndrome, also called DeSanto-Shinawi syndrome (DESSH, OMIM 616708), is a rare autosomal dominant intellectual disability syndrome caused by loss-of-function WAC gene variants at 10p12.1, with hypotonia, dysmorphism, and ADHD-type behavior.

Wagner disease

Wagner disease, also called Wagner syndrome or VCAN-related vitreoretinopathy, is a rare autosomal dominant hereditary vitreoretinopathy caused by VCAN splice-site mutations, producing an optically empty vitreous, myopia, early cataract, chorioretinal atrophy, and retinal detachment.

Whiplash (medicine)

Whiplash, or whiplash-associated disorder (WAD), is a neck injury from sudden acceleration-deceleration of the head, usually in car crashes; graded 0 to IV by the Quebec Task Force, mostly self-limiting, treated mainly with exercise.

White-Sutton syndrome

White-Sutton syndrome (WHSUS, OMIM 616364), also called POGZ-related intellectual disability syndrome, is a rare autosomal dominant neurodevelopmental disorder caused by heterozygous POGZ variants, usually de novo, causing intellectual disability, speech delay, hypotonia, autism features, and obesity.