Medullary (Caudal) Ipsilateral Hemiplegia, often referred to as Opalski syndrome, is a rare form of brainstem stroke in which the infarct involves the lateral ...
Pontine (Lower) Ipsilateral Hemiplegia is a rare neurological syndrome characterized by paralysis or severe weakness of the limbs on the same side of the body ...
Midbrain (Caudal) Ipsilateral Hemiplegia is a rare neurological condition characterized by paralysis of one side of the body (hemiplegia) on the same side as a ...
Spinal cord ipsilateral hemiplegia is a type of paralysis affecting one side of the body below the level of a spinal cord injury on the same side. In simple ...
Brainstem Ipsilateral Hemiplegia refers to paralysis affecting one side of the body (hemiplegia) that occurs on the same side (ipsilateral) as a lesion in the ...
Supratentorial Ipsilateral Hemiplegia is a rare neurological condition in which paralysis of one side of the body occurs on the same side as a lesion located ...
Pure sensory midbrain hemorrhage is a rare type of intracerebral bleed localized to the midbrain tegmentum that produces isolated sensory disturbances without ...
Hemorrhagic Medial Midbrain Sensory Syndrome is a rare neurological condition caused by a small bleed (hemorrhage) in the medial portion of the midbrain—the ...
Ischemic Medial Midbrain Sensory Syndrome (IMMSS) is a rare neurological condition characterized by sensory disturbances due to a small stroke affecting the ...
Medial Midbrain Sensory Syndrome (MMSS) is a rare brainstem stroke characterized by interruption of the medial lemniscus pathway within the midbrain, leading ...
Central facial sensory loss refers to a reduction or absence of sensation in areas of the face due to damage within the central nervous system, rather than the ...
Lateral Brainstem Sensory Syndrome is a neurological condition marked by distinctive patterns of sensory loss due to damage in the side (lateral aspect) of the ...
Ipsilateral hemiplegia refers to paralysis affecting one side of the body (the “hemi-” meaning half and “-plegia” meaning paralysis) that occurs on the same ...
Contralateral hemiplegia is a neurological condition characterized by complete or near-complete paralysis of one side of the body that occurs opposite ...
Medial Brainstem Sensory Syndrome is a condition that arises when the central sensory pathways running through the middle (medial) part of the brainstem are ...
Central facial sensory loss refers to a reduction or absence of sensation in areas of the face due to damage within the central nervous system, rather than the ...
Brainstem sensory loss refers to the impairment or absence of sensory functions—such as touch, pain, temperature, vibration, or proprioception—resulting from ...
A cortical internal capsule lesion refers to damage affecting the white-matter fibers that originate in the cerebral cortex and converge into the internal ...
Cortical (parietal) sensory syndrome is a neurological condition arising from damage to the parietal lobe’s sensory cortex—the area of the brain responsible ...
Thalamic pure sensory stroke is a specialized form of lacunar stroke that affects the thalamus, a deep brain structure crucial for processing and relaying ...
Pure hemianesthesia is a neurological condition in which a person loses all forms of sensation—such as touch, pain, temperature, vibration, and position ...
Palatal myoclonus, also known as palatal tremor, is a rare movement disorder characterized by involuntary, rhythmic contractions of the soft palate muscles ...
Athetoid hand refers to a movement disorder characterized by slow, involuntary, writhing motions of the fingers, hands, and sometimes the forearms. These ...
Isolated hemichorea is a rare neurological movement disorder characterized by involuntary, irregular, non-rhythmic, and “dance-like” movements affecting only ...
Pure dysarthria is a motor speech disorder characterized by impaired articulation, phonation, resonance, respiration, and/or prosody, without accompanying ...
Sensorimotor stroke is a form of stroke in which weakness or clumsiness (motor loss) and numbness, tingling, or loss of position sense (sensory loss) appear ...
Dysarthria–Clumsy Hand Syndrome (DCHS) is a small-vessel (“lacunar”) stroke syndrome in which a pinpoint blockage deep inside the brain injures the fibres that ...
Ataxic-hemiparesis is a lacunar stroke syndrome in which weakness on one side of the body (hemiparesis) is accompanied by in-coordination of the same limbs ...
A pure sensory stroke (PSS) is a very small (“lacunar”) stroke that damages one of the narrow, deep-lying arteries that feed the relay stations for touch, ...
Pure Motor Hemiparesis (PMH) is a neurological condition in which a person suddenly develops weakness or partial paralysis on one entire side of the ...
A lacunar stroke is a small, deep brain infarct—usually less than 15 mm across—that occurs when one of the brain’s tiny “penetrating” arteries becomes blocked. ...
L1 syndrome, also called the L1CAM-related disorder spectrum, is a group of inherited conditions caused by pathogenic changes in the L1 cell-adhesion-molecule ...
Korsakoff syndrome is a chronic, long-lasting brain disorder that develops when the body has been severely short of vitamin B-1 (thiamine) for an extended ...
Kohlschütter–Tönz Syndrome (OMIM #226750) is an ultra-rare, autosomal-recessive neurodevelopmental disorder first described in a Swiss family in 1974. Fewer ...
Klüver–Bucy syndrome is a rare neuro-behavioral disorder that appears when both medial temporal lobes—especially the amygdala and hippocampus—are damaged by ...
Karak syndrome is an ultra-rare, inherited neurological disease in which toxic amounts of iron build up in deep brain structures—especially the basal ganglia ...
Vernet syndrome, also known as jugular foramen syndrome, is a rare disorder that happens when the group of nerves that travel through a key opening in the ...
Jugular bulb thrombosis is a blood-clotting disorder that blocks the venous “bulb” where the sigmoid sinus drains into the upper internal jugular vein at the ...
Villaret Syndrome is a rare but striking neurological condition in which a single injury sitting deep inside the upper neck—the retro-parotid (parapharyngeal) ...
Collet-Sicard syndrome (CSS) is a rare but dramatic neurological disorder in which all four “lower” cranial nerves—IX (glossopharyngeal), X (vagus), XI ...
Jugular foramen syndrome (JFS), often called Vernet syndrome, is a rare skull-base condition in which anything that irritates or squashes the jugular ...
Joubert syndrome (JS) is a rare, inherited condition in which the back part of a baby’s brain—the cerebellar vermis—and the adjoining brain-stem fail to finish ...
Jaffe–Campanacci syndrome (JCS) is an extremely rare bone-and-skin condition in which a child or young adult develops many non-ossifying fibromas—soft, fibrous ...
Incontinentia pigmenti (IP) is a rare, X-linked dominant genetic condition that mainly affects girls because boys who inherit the faulty gene (IKBKG/NEMO) ...
Horner’s syndrome (sometimes called oculosympathetic paresis) is a cluster of eye- and face-related changes that appear when the three-neuron sympathetic nerve ...
Hereditary hemorrhagic telangiectasia—also called Osler-Weber-Rendu disease—is a rare, lifelong, inherited condition that makes some blood vessels grow in an ...
Hemimegalencephaly (HME) is a rare birth defect in which one half of the brain grows abnormally large and disorganized. The over-growth distorts the normal ...
Heerfordt syndrome is a rare, face-and-eye-centred form of the systemic disease sarcoidosis. In sarcoidosis the body’s immune system builds tiny clusters of ...
HEC syndrome is an extremely rare birth disorder in which H = communicating Hydrocephalus (excess fluid around the brain), E = Endocardial Fibroelastosis ...
Harlequin syndrome (HS) is a rare problem of the body’s “automatic” (autonomic) nervous system. In HS, the tiny sympathetic nerves that normally make both ...
Hamanishi-Ueba-Tsuji syndrome is an extremely rare hereditary motor-and-sensory neuropathy first described in Japan in 1985. Babies are born with absent or ...
Miller Fisher Syndrome is a rare, nerve-related illness that belongs to the Guillain-Barré Syndrome (GBS) family. While classic GBS mostly weakens the limbs, ...
Acute Motor-Sensory Axonal Neuropathy (often shortened to AMSAN) is one of the rarer, more aggressive “axonal” forms of Guillain-Barré syndrome (GBS). In ...
Acute Motor Axonal Neuropathy—usually shortened to AMAN—is a fast-moving, immune-related attack on the motor (movement-controlling) portions of the peripheral ...
Acute Inflammatory Demyelinating Polyradiculoneuropathy—usually shortened to AIDP—is an autoimmune attack on the insulating myelin sheath that normally helps ...
Guillain–Barré syndrome is an uncommon but serious autoimmune nerve disorder in which the body’s own immune system suddenly turns against the peripheral ...
Gradenigo’s syndrome is the name doctors give to a very specific complication of a middle-ear infection. When bacteria in an episode of acute or chronic otitis ...
Gómez–López-Hernández syndrome (GLHS)—also called cerebello-trigeminal-dermal dysplasia—is an extremely rare neuro-cutaneous disorder first described in 1979. ...
Gillespie syndrome (GS) is an ultra-rare genetic disorder that blends partial or “scalloped” aniridia, congenital or slowly progressive cerebellar ataxia, and ...
Gerstmann–Sträussler–Scheinker syndrome is a very rare, inherited brain disease belonging to the group of human prion disorders. In prion diseases, a perfectly ...
Left-right disorientation (sometimes called left-right confusion or discrimination difficulty) is a neuro-cognitive problem in which a person cannot reliably ...
Finger agnosia is a loss of “finger sense.” A person can feel that a finger is being touched but can’t tell which finger it is, can’t name that finger, and ...
Dysexecutive — sometimes called frontal — acalculia is a loss or severe disturbance of arithmetic ability that springs not from faulty number knowledge itself ...
Spatial acalculia is a specific kind of number-processing problem that appears when the brain’s “map-making” areas are injured or under-developed. People with ...
Agraphic acalculia is an acquired problem in which a person, who once wrote numbers and solved sums without effort, suddenly cannot set figures down on paper ...
Alexic acalculia is a secondary form of acalculia in which the main obstacle to doing arithmetic is an acquired reading problem (alexia). The person can still ...
Aphasic acalculia is an **acquired problem with doing math that happens **because a person also has aphasia—an impairment of spoken or written language after ...
Frontal-executive anarithmetia (sometimes called dysexecutive or frontal acalculia) is a loss or severe reduction of a person’s everyday calculating skills ...
Anarithmetia—also called primary acalculia—is an acquired loss of the very idea of number and of the rules that let us add, subtract, multiply, or divide. ...
Acalculia is an acquired loss of the ability to understand numbers or carry out even the simplest calculations after the brain has been injured by disease or ...
Dementia-related agraphia is a progressive loss of the ability to write that arises because the brain changes that cause dementia also disrupt the complex ...
Cerebellar agraphia is a loss or severe disturbance of handwriting that happens after damage or disease in the cerebellum—the small, densely folded “little ...
Thalamic agraphia is a specific kind of writing problem that appears after damage to the thalamus—the deep, egg-shaped relay station that sits in the centre of ...
Apraxic Agraphia—also called motor-planning agraphia—is a writing disorder that happens when the brain can no longer organize the precise, sequential finger ...
Deep agraphia is a central writing disorder that sits at the “deep” end of the agraphia spectrum: people can still hold a pen, but when they try to spell they ...
Lexical agraphia—more often called surface agraphia—is an acquired writing disorder in which a person can still spell regular, phonetically predictable words ( ...
Agraphia is the acquired loss or breakdown of the ability to write. “Phonological agraphia” is one special, clinically recognised subtype in which the link ...
Agraphia is the acquired inability or severe difficulty to write meaningful words, sentences, or numbers after previously learning how to do so. It usually ...
Pure—or isolated—agraphia is an acquired loss of the previously normal ability to write without parallel problems in reading, speaking, or motor strength. In ...
Agraphia is a neurological language disorder in which a person loses the ability to write words, sentences, or even single letters that they once knew how to ...
Gerstmann syndrome is a rare but clearly recognisable brain-based disorder. It happens when a small patch of the left parietal lobe—near the angular ...
Fryns syndrome (FS) is a very rare, autosomal-recessive condition in which a baby is born with a distinctive combination of problems that begin during the ...
Frey’s syndrome (also called auriculotemporal syndrome or gustatory sweating) is a nerve-related condition in which part of the face—usually the cheek, temple ...
Fragile X-associated tremor/ataxia syndrome, usually shortened to FXTAS, is a progressive brain-and-nerve disorder that appears most often in people over 50 ...
Fragile X syndrome is the most common inherited cause of intellectual disability and a major single-gene trigger of autism-spectrum traits. It happens when a ...
FOXG1 syndrome is a rare, genetic, life-long neuro-developmental condition caused by harmful changes (mutations, deletions or duplications) in the FOXG1 gene. ...
Foville’s syndrome is a rare brainstem stroke syndrome caused by a lesion in the inferomedial aspect of the pons. First described in 1858 by Achille Louis ...
Pseudo-Foster Kennedy Syndrome is a neurological and ophthalmological condition characterized by optic nerve changes in both eyes—one eye shows optic atrophy ...
Progressive Bilateral Atrophy (PBA) is a descriptive term used when tissues—most often muscles, nerves, or even bones—shrink and weaken on both sides of the ...
Bilateral papilledema is the symmetrical swelling of the optic nerve head in both eyes, seen on fundus examination. It results from increased intracranial ...
Classic Unilateral Atrophy with Contralateral Papilledema (CUACP) is a rare eye-brain disorder in which one optic nerve wastes away (atrophy) while the optic ...
Foster Kennedy syndrome is a rare neuro-ophthalmic condition characterized by a combination of optic nerve atrophy in one eye and papilledema (swelling of the ...
Foix–Alajouanine syndrome is a rare neurological disorder characterized by a slowly progressive myelopathy—damage to the spinal cord—caused by chronic venous ...
Flynn–Aird syndrome is a very rare, hereditary neuroectodermal disorder that affects multiple body systems—including the nervous, skin, skeletal, ocular, ...
Febrile Infection-Related Epilepsy Syndrome (FIRES) is a rare, catastrophic epileptic encephalopathy that strikes previously healthy individuals—most often ...
Transmissible spongiform encephalopathies (TSEs), often called prion diseases, are a rare class of fatal brain disorders caused by misfolded forms of the prion ...
Prion diseases, also known as transmissible spongiform encephalopathies (TSEs), are a group of rare, progressive neurodegenerative disorders caused by ...
Familial Alzheimer-like prion disease is an exceptionally rare, inherited prion disorder characterized by the accumulation of abnormal prion protein (PrP) in ...
Primary familial brain calcification—sometimes still called Fahr’s disease—is a rare, inherited neuro-degenerative condition in which calcium crystals slowly ...
Paraneoplastic overlap syndromes are a group of conditions in which a hidden or established cancer triggers symptoms and signs in body systems distant from the ...
Facial onset sensory and motor neuronopathy (FOSMN) is a rare, slowly progressive neurological disorder in which sensory disturbances—typically in the face—are ...
Isolated Exploding Head Syndrome (EHS) is a benign sensory parasomnia. People with EHS suddenly hear a very loud noise—like an explosion, gunshot, or ...
Chronic Exploding Head Syndrome (EHS) is a benign sensory parasomnia characterized by the perception of a sudden, loud noise—often described as an explosion, ...
Exploding head syndrome (EHS) is a benign sensory parasomnia in which an individual perceives a sudden, loud noise—often described as an ...
Hypnagogic Exploding Head Syndrome, often called EHS, is a benign sleep-related disorder in which a person perceives a sudden, loud noise—such as an explosion, ...
Exploding Head Syndrome (EHS) is a benign parasomnia characterized by the perception of a sudden loud noise or explosive sensation in the head during ...
Epilepsy with intellectual disability is a complex neurological condition in which recurrent, unprovoked seizures occur alongside significant limitations in ...
EAST syndrome (also known as SeSAME syndrome) is a rare, inherited disorder defined by the combination of four key features: Epilepsy, Ataxia, Sensorineural ...
Emotional Dysexecutive Syndrome is a condition in which damage to executive brain networks—especially in the frontal lobes—impairs a person’s ability to ...
Behavioural Dysexecutive Syndrome (BDS) is a pattern of problems that arise when the brain’s “executive” control system becomes impaired. Executive functions ...
Cognitive Dysexecutive Syndrome is a pattern of thinking and behavior problems resulting from damage to the brain’s executive control systems. These ...
Dysexecutive syndrome (DES) is a pattern of cognitive, behavioural, and emotional difficulties that arise when the brain’s executive functions are impaired. ...
