1,527 articles
Pediatric multiple sclerosis
Pediatric multiple sclerosis (POMS) is MS beginning before age 18, about 3-5% of cases; relapsing-remitting in 95-98%, higher relapse rates, slower physical but earlier disability, and lasting cognitive effects.
Pediatric neurology
Pediatric neurology, or child neurology, is the specialty treating nervous system diseases of infants and children. Key facts: flagship journal Pediatric Neurology (Elsevier, ISSN 0887-8994, founded 1985 by Kenneth Swaiman), literature dominated by epilepsy, neuroimmunology, and neurodevelopment research.
PEHO syndrome
PEHO syndrome (progressive encephalopathy with edema, hypsarrhythmia, optic atrophy) is a rare infantile genetic disorder with extreme cerebellar atrophy, first described in Finnish patients, caused chiefly by ZNHIT3 mutations but genetically heterogeneous.
Pelizaeus-Merzbacher disease
Pelizaeus-Merzbacher disease (PMD), an X-linked hypomyelinating leukodystrophy caused by PLP1 mutations (duplications, missense, null), causing nystagmus, spasticity, and ataxia; distinct from GJC2-related PMLD1.
Pelizaeus-Merzbacher-like disease
Pelizaeus-Merzbacher-like disease (PMLD, ORPHA:280270) is an autosomal recessive hypomyelinating leukodystrophy mimicking X-linked PMD; main gene GJC2 (connexin 47), also HSPD1, AIMP1, SLC16A2, MAL; onset neonatal or infancy.
Pendred syndrome
Pendred syndrome (goiter-deafness syndrome) is an autosomal recessive disorder from SLC26A4 mutations causing pendrin dysfunction, bilateral sensorineural hearing loss, enlarged vestibular aqueduct, and often euthyroid goiter.
Perinatal arterial stroke
Perinatal arterial ischemic stroke (PAIS, neonatal arterial ischemic stroke) is arterial-brain infarction between late gestation and day 28 of life, presenting with focal seizures, diagnosed by MRI, causing hemiparetic cerebral palsy.
Periodic limb movement disorder
Periodic limb movement disorder (PLMD): a diagnosis-of-exclusion sleep disorder with PLMI >15/h (adults), NREM-clustered leg movements, distinguished from RLS; 2024 AASM favors alpha-2-delta ligands over dopamine agonists.
Perioral myoclonia with absences
Perioral myoclonia with absences (PMA/POMA) is a rare idiopathic generalized epilepsy syndrome, first described by Panayiotopoulos in 1994, in which absence seizures are accompanied by rhythmic mouth-muscle jerks, tonic-clonic seizures, absence status, and drug resistance; not yet ILAE-recognized.
Periostitis of orbit
Periostitis of orbit (orbital periostitis) is inflammation of the orbital periosteum, coded ICD-10 H05.03 and ICD-11 9A21.3, usually from trauma or spreading sinus infection, stage II of sinusitic orbital complications.
Peripapillary staphyloma
Peripapillary staphyloma (ORPHA:519400, ICD-10 Q14.2) is a rare congenital optic disc excavation: deep chorioretinal atrophic excavation around a normal disc, normal vessels, no glial tuft, mostly unilateral poor vision, Curtin type III.
Peripheral demyelinating neuropathy-central dysmyelinating leukodystrophy-Waardenburg syndrome-Hirschsprung disease
PCWH (OMIM 609136), also called neurologic Waardenburg-Shah syndrome or WS4 plus, is a rare autosomal dominant SOX10-related disorder combining Waardenburg-Shah features with demyelinating neuropathy and central leukodystrophy; fewer than 50 cases reported.
Peripheral neuropathy
Peripheral neuropathy is damage to peripheral nerves causing numbness, pain, weakness, or autonomic dysfunction; over 100 types exist. Diabetes is the leading cause, affecting up to 50% of long-term diabetics; monofilament screening sensitivity ranges 41-93%.
Peripheral retinal degeneration
Peripheral retinal degeneration is a group of acquired or congenital retinal lesions outside the macula in which tissue thins, splits, or atrophies, sometimes leading to rhegmatogenous retinal detachment.
Perry syndrome
Perry syndrome (parkinsonism with alveolar hypoventilation and mental depression) is a rare autosomal dominant neurodegenerative disease caused by DCTN1 mutations, causing parkinsonism, depression, weight loss, and nocturnal hypoventilation, with death typically within about five years.
Persistent hyperplastic primary vitreous
Persistent hyperplastic primary vitreous (PHPV), now called persistent fetal vasculature (PFV), is a congenital eye malformation from failed hyaloid vessel regression, usually unilateral, causing infantile leukocoria, microphthalmia, and cataract, and mimicking retinoblastoma.
Persistent idiopathic facial pain
Persistent idiopathic facial pain (PIFP), formerly atypical facial pain, is a rare chronic facial pain recurring daily over 3 months without neurological deficit or identifiable cause, treated conservatively with antidepressants.
Persistent Postural-Perceptual Dizziness
Persistent postural-perceptual dizziness (PPPD), also called chronic subjective dizziness or phobic postural vertigo, is a chronic functional vestibular disorder defined by Bárány Society 2017 criteria: persistent non-spinning dizziness on most days for 3+ months, worsened by upright posture, motion, and visual stimuli; ICD-11 code AB32.0.
Persistent pupillary membranes
Persistent pupillary membrane (PPM), remnants of the fetal tunica vasculosa lentis, appears as iris strands crossing the pupil; seen in about 95% of neonates and 20% of adults, usually asymptomatic, treated only if vision-threatening.
Persistent vegetative state
Persistent vegetative state (PVS), also called unresponsive wakefulness syndrome, is complete unawareness with sleep-wake cycles after brain injury lasting over 1 month; misdiagnosis reaches 37–43% and some patients recover consciousness.
Perverted nystagmus
Perverted nystagmus, now termed cross-coupled nystagmus by the Barany Society, is nystagmus arising in a plane different from the stimulus, classically vertical or rotatory caloric nystagmus, usually indicating central vestibular or cerebellar pathology though it can be a normal variant.
PHACE syndrome
PHACE syndrome (PHACES) is a rare neurocutaneous disorder of segmental facial infantile hemangioma with posterior fossa, arterial, cardiac, and eye anomalies; first named in 1996, criteria set in 2009 and 2016.
Phacoanaphylactic uveitis
Phacoanaphylactic uveitis, also called phacoantigenic or lens-induced uveitis, is a rare granulomatous eye inflammation triggered by lens proteins released after capsular rupture from trauma, surgery, or hypermature cataract; treated by removing lens material.
Phantosmia
Phantosmia, or olfactory hallucination, is smelling odors that are not present. Causes include infections, allergies, nasal polyps, migraines, COVID-19, and rarely Parkinson's, stroke, or brain tumors; treatment targets the underlying cause.
Pharyngeal-cervical-brachial variant of Guillain-Barré syndrome
Pharyngeal-cervical-brachial (PCB) variant of Guillain-Barré syndrome, also called PCB-GBS: a rare localized axonal GBS subtype causing oropharyngeal, neck, and arm weakness with areflexia, linked to anti-GT1a IgG antibodies.
Photic retinopathy
Photic retinopathy, also called solar retinopathy or eclipse retinopathy, is retinal damage caused by intense light exposure, most often from sungazing, eclipse viewing, welding arcs, or laser pointers.
Photic sneeze reflex
The photic sneeze reflex (PSR), also known as ACHOO syndrome or sun sneezing, is involuntary sneezing triggered by bright light, affecting an estimated 25% of people and inherited in an autosomal dominant manner.
Photophobia
Photophobia is abnormal light sensitivity causing eye discomfort or pain, a symptom of migraine (85-90% of patients), dry eye, blepharospasm, and TBI, mediated by melanopsin ipRGCs and treated by addressing the cause plus FL-41 tinted lenses.
Photosensitive occipital lobe epilepsy
Photosensitive occipital lobe epilepsy (POLE, formerly IPOLE) is a rare childhood-onset reflex epilepsy with occipital focal visual seizures triggered by flickering light, TV, and video games; normal MRI, female predominance, good remission.
Phthisis bulbi
Phthisis bulbi (end-stage eye), ICD-11 9C22.1, is the shrunken, collapsed, non-functional globe after severe trauma, uveitis, infection, surgery, or tumor; vision loss is permanent, managed by pain relief and prosthetic rehabilitation.