Nervous and sensory conditions

Acute inflammatory demyelinating polyradiculoneuropathy

Acute inflammatory demyelinating polyradiculoneuropathy (AIDP), also called acute inflammatory demyelinating polyneuropathy, is the commonest Guillain-Barré syndrome subtype in Europe and North America, an autoimmune demyelinating neuropathy treated with plasma exchange or IVIg.

Acute motor and sensory axonal neuropathy

Acute motor and sensory axonal neuropathy (AMSAN), also called acute motor-sensory axonal GBS, is a severe axonal Guillain-Barré syndrome subtype with antiganglioside antibodies, poor recovery, and higher frequency in Asia and Latin America.

Acute motor axonal neuropathy

Acute motor axonal neuropathy is a rare pure motor form of Guillain-Barré syndrome, identified in China in the early 1990s and often triggered by Campylobacter jejuni infection.

Acute necrotizing encephalopathy of childhood

Acute necrotizing encephalopathy of childhood (ANEC, ANE) is a rare post-infectious encephalopathy with bilateral symmetric thalamic necrosis, cytokine storm, RANBP2-related familial ANE1, and 5–30% mortality.

Acute pandysautonomia

Acute pandysautonomia, also called acute panautonomic neuropathy, is a rare Guillain-Barré syndrome variant with acute post-ganglionic sympathetic and parasympathetic failure after infection; now mostly classified as autoimmune autonomic ganglionopathy.

Acute posterior multifocal placoid pigment epitheliopathy

APMPPE (acute posterior multifocal placoid pigment epitheliopathy), also called épithéliopathie en plaques, is a rare bilateral inflammatory chorioretinopathy of young adults with placoid posterior-pole lesions, choriocapillaris ischemia, and mostly spontaneous visual recovery.

Acute repetitive seizures

Acute repetitive seizures (seizure clusters, cluster or serial seizures) are closely grouped seizures in epilepsy, increased from the patient's baseline, with recovery between seizures; ICD-11 8A67, treated with benzodiazepine rescue medication.

Acute sensory ataxic neuropathy

Acute sensory ataxic neuropathy (ASAN) is a rare Guillain-Barré syndrome variant that begins days to weeks after infection, causing sensory ataxia, areflexia, and positive Romberg sign with minimal weakness.

Acute vestibular syndrome

Acute vestibular syndrome (AVS) is a syndrome of acute-onset, continuous vertigo or unsteadiness lasting days to weeks, caused most often by vestibular neuritis or posterior circulation stroke.

Acute zonal occult outer retinopathy

Acute zonal occult outer retinopathy (AZOOR), also called AZOOR complex-related disease, is a rare inflammatory outer retinal disorder first described by Gass in 1992, causing photopsias and scotomas with a normal-appearing fundus, mainly in young myopic women.

Adherent leukoma

Adherent leukoma (leukoma adhaerens, leucome adhérent): a dense white corneal scar with iris fused to its back surface after corneal perforation; ICD-10 H17.0, ICD-11 9A77.1; treated by keratoplasty.

Adhesive middle ear disease

Adhesive middle ear disease (adhesive otitis media, ICD-11 AB17, ICD-10 H74.1) is chronic fibrosis and adhesion in the tympanic cavity limiting eardrum and ossicle mobility, causing conductive hearing loss after otitis media; distinct from glue ear.

Adult-onset autosomal dominant leukodystrophy

Adult-onset autosomal dominant leukodystrophy (ADLD, OMIM 169500) is a rare LMNB1-duplication demyelinating disorder starting in the fourth to sixth decade with autonomic dysfunction, ataxia, and spasticity, often mimicking primary progressive multiple sclerosis.

Adult-onset autosomal recessive cerebellar ataxia

Adult-onset autosomal recessive cerebellar ataxia, also known as SCAR10 or ARCA3, is a rare genetic neurodegenerative disease caused by ANO10 variants, causing progressive gait ataxia, dysarthria, and cerebellar atrophy.

Adult-onset cervical dystonia, DYT23 type

Adult-onset cervical dystonia, DYT23 type (ORPHA:420492, Dystonia 23) is a rare autosomal dominant isolated dystonia from CIZ1 mutations at 9q34, causing adult-onset non-progressive focal cervical dystonia with torticollis, sometimes head and limb tremor; prevalence under 1 in 1,000,000, OMIM 614860.

Adult-onset leukoencephalopathy with axonal spheroids and pigmented glia

ALSP (formerly HDLS and POLD) is a rare adult-onset, autosomal dominant white matter disease caused by CSF1R mutations, causing dementia, parkinsonism, seizures, and early death.

Advanced sleep-wake phase disorder

Advanced sleep-wake phase disorder (ASWPD), formerly advanced sleep phase disorder, is a circadian rhythm sleep-wake disorder with persistently early sleep onset and morning awakening, often familial, treated with evening light therapy.

Age-related cataract

Age-related cataract (senile cataract) is lens opacification from aging, beginning around age 40 as lens proteins clump. Nuclear, cortical, and posterior subcapsular subtypes; leading cause of blindness worldwide; treated only by surgery.

Agnosia

Agnosia is the inability to recognize stimuli despite intact sensation, coined by Freud in 1891; divided by Lissauer into apperceptive and associative forms, caused by stroke, injury, tumors, or dementia.

Agraphia

Agraphia (ICD-11 MB4B.3) is the acquired loss of the ability to write, usually after stroke or brain injury. Divided into central (linguistic) and peripheral (motor) subtypes including apraxic, allographic, and phonological agraphia.

Aicardi syndrome

Aicardi syndrome: rare X-linked dominant neurodevelopmental disorder of females, defined by agenesis of the corpus callosum, chorioretinal lacunae, and infantile spasms; cause unknown.

Aicardi-Goutières syndrome

Aicardi-Goutières syndrome (AGS), a rare genetic interferonopathy and leukodystrophy mimicking congenital infection; nine causative genes including TREX1 and RNASEH2B; genotype-linked mortality and emerging JAK-inhibitor trials.

Åland Islands eye disease

Åland Islands eye disease (AIED, Forsius-Eriksson syndrome) is a rare X-linked recessive retinal disorder caused by CACNA1F mutations, with fundus hypopigmentation, nystagmus, myopia, protan defect, and night blindness, but no optic nerve misrouting.

Albinism-deafness syndrome

Albinism-deafness syndrome (albinism-hearing loss syndrome, ADFN, OMIM 300700) is an X-linked recessive rare disorder of congenital sensorineural deafness with piebaldness, no ocular albinism, mapped to Xq26.3-q27.1, distinct from Tietz syndrome.

Alcohol intoxication

Alcohol intoxication, or drunkenness and alcohol poisoning, is CNS depression from ethanol accumulating faster than the liver clears it; GABA-A potentiation, NMDA inhibition, zero-order elimination, BAC 0.08% binge threshold, coma risk above 50 mM.

Alcohol-related neurological disorders

Alcohol-related neurological disorders (ICD-11 8D44): acute intoxication, withdrawal, Wernicke-Korsakoff syndrome, alcohol-related dementia, cerebellar degeneration, alcoholic neuropathy and myopathy caused by ethanol neurotoxicity and thiamine deficiency.

Alcoholic polyneuropathy

Alcoholic polyneuropathy, also called alcohol-related peripheral neuropathy, is nerve damage from long-term heavy drinking. Affects about 46% of chronic alcohol abusers by nerve conduction studies; main risk factor is total lifetime ethanol dose; treated with abstinence plus thiamine.

Alexander disease

Alexander disease, a rare GFAP-gene leukodystrophy and primary astrocyte disorder marked by Rosenthal fibers, infantile to adult forms, supportive care, and the 2026 FDA approval of zilganersen.

Alice in Wonderland syndrome

Alice in Wonderland syndrome (AIWS, Todd's syndrome), named by John Todd in 1955, is a perceptual disorder causing distortions of body size, object size, and time, mostly linked to migraine, infections, and epilepsy.