Nervous and sensory conditions

Chronic angle-closure

Chronic angle-closure, or chronic primary angle-closure glaucoma (PACG), is the gradual, often silent form of angle-closure eye disease causing raised intraocular pressure and optic nerve damage; treated with laser iridotomy or lens extraction (EAGLE trial).

Chronic cancer pain

Chronic cancer related pain (ICD-11 MG30.1) is chronic pain from active cancer or metastases or from cancer treatment, coded as chronic cancer pain (MG30.10) or chronic post-cancer treatment pain (MG30.11), diagnosed after more than 3 months.

Chronic central neuropathic pain

Chronic central neuropathic pain (ICD-11 MG30.50) is chronic pain from a lesion or disease of the central somatosensory system, caused mainly by stroke, spinal cord injury, and multiple sclerosis, treated first-line with antidepressants and gabapentinoids.

Chronic enlargement of lacrimal gland

Chronic lacrimal gland enlargement, or chronic dacryoadenitis, is persistent tear-gland swelling mainly from nonspecific dacryoadenitis, IgG4-related disease, or lymphoma, differentiated by age, laterality, gland size, wedge sign, and extra-orbital involvement.

Chronic hiccup

Chronic hiccup, medically called singultus, is a rare movement disorder in which hiccups last over 48 hours, disturbing sleep and eating and often signaling underlying disease.

Chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP), or polyradiculoneuropathy, is an autoimmune peripheral nerve disorder attacking myelin, causing progressive weakness and numbness over at least 8 weeks; treated with IVIg, steroids, plasma exchange, and efgartigimod.

Chronic migraine

Chronic migraine, also called CM, is headache on 15+ days/month for over 3 months with migraine features on 8+ days (ICHD-3). Preventives with trial evidence include CGRP antibodies, onabotulinumtoxinA, topiramate, eptinezumab, and atogepant.

Chronic neuropathic orofacial pain

Chronic neuropathic orofacial pain (ICD-11 MG30.62) is chronic orofacial pain from a peripheral somatosensory lesion, covering trigeminal neuralgia, trigeminal neuropathy, and related cranial neuralgias, diagnosed by neuroanatomically plausible pain plus sensory signs.

Chronic neuropathic pain

Chronic neuropathic pain is chronic pain lasting 3 months or longer, caused by a lesion or disease of the somatosensory nervous system, affecting peripheral or central structures.

Chronic peripheral neuropathic pain

Chronic peripheral neuropathic pain, ICD-11 code MG30.51, is chronic pain from a lesion or disease of the peripheral somatosensory nervous system, persisting or recurring at least 3 months, diagnosed by plausible neuroanatomical distribution and graded possible, probable, or definite.

Chronic post cancer treatment pain

Chronic post cancer treatment pain (ICD-11 MG30.11) is chronic pain caused by cancer treatment such as chemotherapy, radiotherapy, or surgery, including CIPN, lasting over 3 months and distinct from tumor recurrence pain.

Chronic secondary headache or orofacial pain

Chronic secondary headache or orofacial pain is an ICD-11 diagnostic category (code MG30.6) covering headache or facial pain from an identified underlying cause on 15 or more days a month.

Chronic tension-type headache

Chronic tension-type headache (CTTH, ICHD-3 2.3, ICD-11 8A81.2) is a primary headache with headache on 15+ days/month, bilateral pressing pain; amitriptyline is first-line prophylaxis, with acupuncture and physiotherapy as options.

Chronic traumatic encephalopathy

Chronic traumatic encephalopathy (CTE) is a progressive tauopathy linked to repetitive head impacts in contact sports, military service, and domestic violence; diagnosable only postmortem, with contested prevalence and dose–response.

Chronic vestibular syndrome

Chronic vestibular syndrome (ICD-11 AB32): persistent vertigo, dizziness, or unsteadiness lasting months to years. Main causes include PPPD, bilateral vestibulopathy, and presbyvestibulopathy.

Chudley-McCullough syndrome

Chudley-McCullough syndrome (CMS, MIM 604213), a rare autosomal-recessive GPSM2-related disorder: severe congenital sensorineural deafness with distinctive brain malformations (callosal agenesis, polymicrogyria, heterotopia) but usually preserved cognition.

Ciliary block glaucoma

Ciliary block glaucoma (malignant glaucoma, aqueous misdirection; ICD-11 9C61.35): rare secondary angle-closure glaucoma with aqueous misdirection into the vitreous, forward lens-iris displacement, and raised IOP despite patent iridotomy; treated with cycloplegics and vitrectomy.

Circadian rhythm sleep disorder

Circadian rhythm sleep disorder (circadian rhythm sleep-wake disorder, CRSWD): sleep timing disorder from altered circadian clock or misalignment; six ICSD-2 types; treated with timed light, melatonin, lifestyle change.

Circumscribed choroidal hemangioma

Circumscribed choroidal hemangioma (CCH) is a rare benign vascular tumor of the choroid, distinct from the diffuse Sturge-Weber-associated form. Orange-red posterior pole mass causing subretinal fluid; often misdiagnosed; treated with photodynamic therapy or radiotherapy.

CLCN4-related X-linked intellectual disability syndrome

CLCN4-related X-linked intellectual disability syndrome, also called Raynaud-Claes syndrome (MRXSRC, OMIM 300114), is a rare Xp22.2 chloride/proton exchanger gene disorder causing intellectual disability, epilepsy, and behavioral problems in males and females.

Clinical anophthalmos

Clinical anophthalmos is the apparent complete absence of one or both eyes at birth; most cases actually retain residual ocular tissue, making them extreme microphthalmos.

CLIPPERS

CLIPPERS (chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids) is a rare steroid-responsive CNS inflammatory disorder, first described in 2010, causing subacute brainstem symptoms with punctate gadolinium-enhancing pontine lesions on MRI.

CLN1 disease

CLN1 disease (infantile neuronal ceroid lipofuscinosis, Santavuori-Haltia disease, infantile Batten disease) is an autosomal recessive lysosomal storage disorder from PPT1 deficiency, causing psychomotor regression, seizures, blindness by age 2, and early death; later-onset variants exist.

CLN12 disease

CLN12 disease, also called ATP13A2-related juvenile neuronal ceroid lipofuscinosis or NCL12, is a rare autosomal recessive lysosomal storage disorder from ATP13A2 mutations, causing juvenile-onset ataxia, myoclonus, parkinsonism and cognitive decline, distinct from Kufor-Rakeb syndrome and SPG78.

CLN2 disease

CLN2 disease (neuronal ceroid lipofuscinosis type 2, NCL2) is an autosomal recessive lysosomal storage disorder from TPP1 deficiency, causing seizures, motor-language loss and blindness from ages 2-4; treated with intraventricular cerliponase alfa (Brineura).

CLN4 disease

CLN4 disease (Parry disease, adult neuronal ceroid lipofuscinosis, NCL4) is a rare autosomal dominant adult-onset NCL caused by DNAJC5 mutations, causing seizures, myoclonus, dementia, and ataxia without vision loss.

CLN6 disease

CLN6 disease (NCL6, neuronal ceroid lipofuscinosis type 6) is a rare autosomal recessive Batten disease caused by CLN6 gene mutations, with late infantile, juvenile, and adult-onset forms involving regression, seizures, and ataxia.

CLN7 disease

CLN7 disease (NCL7, neuronal ceroid lipofuscinosis type 7) is a rare autosomal recessive Batten disease variant caused by MFSD8 mutations, beginning at ages 2-7 with seizures, myoclonus, vision loss, and motor and cognitive decline; no approved cure exists.

Cluster headache

Cluster headache, a trigeminal autonomic cephalalgia or "suicide headache": severe unilateral orbital attacks of 15-180 minutes up to 8 daily, with autonomic symptoms; treated acutely with oxygen and subcutaneous sumatriptan, prevented with verapamil.