1,527 articles
Ganglioneuroblastoma
Ganglioneuroblastoma, also called GNB-intermixed or GNB-nodular, is a rare pediatric neuroblastic tumor of sympathetic tissue mixing neuroblasts and ganglion cells, intermediate between neuroblastoma and ganglioneuroma, classified by the INPC.
Ganglioneuroma
Ganglioneuroma: a rare benign tumor of the sympathetic autonomic nervous system, made of mature ganglion cells and Schwann cells; most often adrenal, retroperitoneal, or mediastinal; treated by surgery when symptomatic, with excellent prognosis.
Gaze-evoked nystagmus
Gaze-evoked nystagmus (GEN, 注視誘発眼振) is jerk nystagmus on eccentric gaze from neural integrator impairment; the most common clinical nystagmus, poorly localizing, caused by drugs, cerebellar disease, MS, and alcohol.
Gelastic seizures with hypothalamic hamartoma
Gelastic seizures with hypothalamic hamartoma (GS-HH, ORPHA:86906) is a rare epilepsy syndrome with early-onset ictal laughter or crying from a non-neoplastic hypothalamic hamartoma, often progressing to intractable epilepsy, cognitive decline, and precocious puberty.
Gelatinous drop-like corneal dystrophy
Gelatinous drop-like corneal dystrophy (GDLD, OMIM 204870), also called subepithelial amyloidosis of the cornea, is a rare autosomal recessive TACSTD2-related corneal amyloidosis causing childhood-onset vision loss, commonest in Japan, with recurrent deposits after keratoplasty.
Generalised tonic seizure
Generalised tonic seizure (ICD-11 8A68.6), a bilateral seizure with sudden sustained muscle stiffening, median 8 seconds, often during sleep; mandatory for Lennox-Gastaut syndrome diagnosis, distinct from tonic-clonic seizures.
Generalized epilepsy-paroxysmal dyskinesia syndrome
Generalized epilepsy-paroxysmal dyskinesia syndrome (GEPD), a rare autosomal dominant channelopathy from KCNMA1 gain-of-function mutations on chromosome 10q22, combines paroxysmal dyskinesia with generalized absence or tonic-clonic epilepsy beginning in childhood.
Generalized tonic–clonic seizure
Generalised tonic-clonic seizure (ICD-11 8A68.4), formerly grand mal: a generalized-onset seizure with tonic stiffening then clonic jerking and loss of awareness, distinct from focal to bilateral tonic-clonic seizures.
Genetic epilepsy with febrile seizure plus
Genetic epilepsy with febrile seizure plus (GEFS+), formerly generalized epilepsy with febrile seizures plus, is an autosomal dominant familial epilepsy spectrum ranging from febrile seizures to Dravet syndrome, most often linked to SCN1A variants.
Gerstmann syndrome
Gerstmann syndrome, also called angular gyrus syndrome, is a rare neuropsychological tetrad of finger agnosia, left-right disorientation, agraphia, and acalculia after dominant parietal lobe lesions, first described by Josef Gerstmann in 1924 and now explained by subcortical white matter disconnection.
Giant axonal neuropathy
Giant axonal neuropathy (GAN), also called giant axonal neurodegeneration, is a rare autosomal recessive disorder caused by GAN gene mutations encoding gigaxonin, causing giant neurofilament-packed axons, kinky hair, childhood-onset progressive neuropathy, and death typically by the third decade.
Glaucomatocyclitic crisis disease
Glaucomatocyclitic crisis disease, or Posner-Schlossman syndrome, a rare recurrent unilateral inflammatory glaucoma with IOP spikes of 40-50 mm Hg, mild uveitis, open angles, and CMV association.
Glioma
Glioma: tumors of glial cells in the brain and spinal cord; main types astrocytoma, oligodendroglioma, ependymoma. Classified by WHO CNS5 (2021) using IDH mutation and 1p/19q codeletion; treated with surgery, radiotherapy, chemotherapy, and new IDH inhibitors.
Gliomas of brain
Gliomas of brain: tumors arising from glial or precursor cells of the CNS, also called glial tumors. Classified by 2021 WHO into adult-type diffuse gliomas (astrocytoma IDH-mutant, oligodendroglioma 1p/19q-codeleted, glioblastoma IDH-wildtype) and pediatric, circumscribed, and other groups; graded I to IV.
Gliomatosis cerebri
Gliomatosis cerebri, a rare diffusely infiltrating glioma growth pattern spanning three or more brain lobes, removed as a distinct WHO entity in 2016; median survival about 13 months.
Gliosis
Gliosis (astrogliosis, astrocytosis, glial scar): reactive proliferation and hypertrophy of neuroglia, mainly astrocytes, after CNS injury, stroke, infection, epilepsy, or neurodegenerative disease, marked by GFAP upregulation.
Glossopharyngeal neuralgia
Glossopharyngeal neuralgia (GPN, Weisenberg syndrome) is a rare cranial neuralgia causing brief, severe unilateral pain in the tongue, throat, ear, and tonsils, usually over age 50, treated with carbamazepine or microvascular decompression.
GNAO1-related developmental delay-seizures-movement disorder spectrum
GNAO1-related developmental delay-seizures-movement disorder spectrum is a rare inherited neurological condition caused by GNAO1 gene changes, causing developmental delay, seizures, and movement disorders such as dystonia.
Goldmann-Favre syndrome
Goldmann-Favre syndrome, also called enhanced S-cone syndrome (ESCS, OMIM 268100), is a rare autosomal recessive vitreoretinal degeneration caused by NR2E3 mutations, with night blindness, nummular pigment clumping, retinoschisis, and pathognomonic ERG findings.
Gómez-López-Hernández syndrome
Gómez-López-Hernández syndrome (cerebellotrigeminal-dermal dysplasia, OMIM 601853) is an ultra-rare neurocutaneous disorder combining rhombencephalosynapsis, scalp alopecia, and often trigeminal anesthesia; about 57 cases reported, cause unknown.
Granulomatous orbital inflammation
Granulomatous orbital inflammation (ICD-11 9A22.2, granuloma of orbit) is orbital inflammation dominated by histiocytes and noncaseating granulomas, either an uncommon subtype of idiopathic orbital inflammation or orbital sarcoidosis or granulomatosis with polyangiitis; treated first with systemic corticosteroids.
Guillain–Barré syndrome
Guillain–Barré syndrome, or GBS, is a rare autoimmune disorder in which the immune system attacks the peripheral nerves, causing weakness that can progress to paralysis.
Guy M. McKhann
Guy M. McKhann (1932–2023) was an American neurologist who founded the Johns Hopkins Department of Neurology in 1969 and established the widely used McKhann Criteria for diagnosing Alzheimer's disease.
Gyrate atrophy of choroid and retina
Gyrate atrophy of the choroid and retina (GACR), gyrate atrophy, hyperornithinemia: rare autosomal recessive retinal degeneration from OAT gene deficiency causing elevated ornithine, night blindness, spiral chorioretinal atrophy, treated with arginine-restricted diet.
Hao-Fountain syndrome
Hao-Fountain syndrome (HAFOUS, OMIM 616863), also called USP7-related neurodevelopmental disorder, is a rare autosomal dominant disorder caused by USP7 variants or 16p13.2 microdeletion, marked by developmental delay, speech delay, autism, hypotonia, and dysmorphic features.
Harlequin syndrome
Harlequin syndrome, a rare dysautonomic disorder first described by Lance et al in 1988, causes unilateral facial flushing and sweating with midline demarcation from contralateral anhidrosis, usually idiopathic or from sympathetic fiber disruption.
Hartsfield syndrome
Hartsfield syndrome (holoprosencephaly-ectrodactyly-cleft lip/palate syndrome, OMIM 615465) is a rare FGFR1-related disorder combining holoprosencephaly, split-hand/foot malformation, cleft lip/palate, and endocrine abnormalities, inherited dominantly or recessively.
Havana syndrome
Havana syndrome, or anomalous health incidents (AHI): symptoms first reported by US Embassy Havana staff in 2016, later hundreds of cases worldwide; cause contested, with US intelligence judging foreign adversary involvement very unlikely and NIH finding no MRI-detectable brain injury.
Head injury
Head injury is trauma to the scalp, skull, or brain, excluding the face and jaws. Also called traumatic brain injury when the brain is affected; graded mild, moderate, or severe by the Glasgow Coma Scale, with primary and secondary injury phases.
Headache
Headache: pain in the head or upper neck; headache disorders include primary types (migraine, tension-type, cluster), secondary types such as medication-overuse headache, and affect about 40% of the global population.