Diseases

Neurofibroma

is a benign nerve sheath tumor in the peripheral nervous system. Usually found in individuals with Neurofibromatosis Type 1 (NF1), a genetically-inherited disease, they can result in a range of symptoms from physical disfiguration and pain to cognitive disability. Neurofibromas arise from Schwann cells that exhibit biallelic inactivation of the NF1 gene that codes for the protein neurofibromin.[1] This protein is responsible for regulating the RAS-mediated cell growth pathway. In contrast to schwannomas, another type of tumor arising from Schwann cells, neurofibromas incorporate many additional types of cells and structural elements in addition to Schwann cells, making it difficult to identify and understand all the mechanisms through which they originate and develop.[2]

Neurofibromatosis type 1

Neurofibromatosis type 1: NF1, a genetic disorder characterized by a number of remarkable skin findings including multiple cafe au lait (coffee with milk) spots, multiple benign tumors called neurofibromas on the skin, plexiform neurofibromas (thick and misshapen nerves due to the abnormal growth of cells and tissues that cover the nerve), and freckles in the armpit and groin. The cafe au lait spots increase in number and size with age. Ninety-seven percent of people with NF1 have 6 or more cafe au lait spots by age 20. The skin neurofibromas appear later, usually in the second decade of life. In NF1 there is an increased risk of scoliosis, optic gliomas (benign tumors on the optic nerve), epilepsy, and learning disability. The risk of malignant degeneration of neurofibromas is below 5 percent. NF1 is inherited in an autosomal dominant manner and is due to mutation of the NF1 gene (in chromosome band 17q11) that encodes a protein called neurofibromin. Half of cases are due to new mutations in the NF1 gene. Prenatal testing is available. Also called von Recklinghausen disease.

Neurofibromatosis type 2

Neurofibromatosis type 2 is a disorder characterized by the growth of noncancerous tumors in the nervous system. The most common tumors associated with neurofibromatosis type 2 are called vestibular schwannomas or acoustic neuromas. These growths develop along the nerve that carries information from the inner ear to the brain (the auditory nerve). Tumors that occur on other nerves are also commonly found with this condition.

Almost all people affected by NF2 develop bilateral (affecting both sides) vestibular schwannomas by age 30 years; however, other tumors of the central nervous system (the brain and spinal cord) are common, as well.

The signs and symptoms of neurofibromatosis type 2 usually appear during adolescence or in a person's early twenties, although they can begin at any age. The most frequent early symptoms of vestibular schwannomas are hearing loss, ringing in the ears (tinnitus), and problems with balance. In most cases, these tumors occur in both ears by age 30. If tumors develop elsewhere in the nervous system, signs and symptoms vary according to their location. Complications of tumor growth can include changes in vision, numbness or weakness in the arms or legs, and fluid buildup in the brain. Some people with neurofibromatosis type 2 also develop clouding of the lens (cataracts) in one or both eyes, often beginning in childhood.

The criteria that were chosen for the diagnosis of NF2 were the following, of which only 1 criterion was needed to make the diagnosis:

  • Bilateral CN VIII masses seen with appropriate imaging techniques (eg, computed tomography [CT] scanning or magnetic resonance imaging [MRI])
  • A first-degree relative with NF2 and either a unilateral CN VIII mass or 2 of the following:
  • Neurofibroma
  • Meningioma
  • Glioma
  • Schwannoma
  • Juvenile posterior subcapsular lenticular opacity

In the past 2 decades, a revision to these diagnostic criteria of NF2 was proposed that concerns the addition of a section for presumptive or probable diagnosis of NF2. These modified criteria are listed as follows:

  • Definite diagnosis of NF2
  • Bilateral CN VIII schwannomas on MRI or CT scan (no biopsy necessary)
  • First-degree relative with NF2 and either unilateral early-onset CN VIII schwannoma (age 2) and unilateral CN VIII schwannoma or 1 of the following:
  • Glioma
  • Schwannoma
  • Juvenile posterior subcapsular lenticular opacity

Neurofibromatosis type 3

Neurofibromatosis, Type III, Riccardi type is listed as a "rare disease" by the Office of Rare Diseases (ORD) of the National Institutes of Health (NIH). This means that Neurofibromatosis, Type III, Riccardi type, or a subtype of Neurofibromatosis, Type III, Riccardi type, affects less than 200,000 people in the US population.

Neurofibromatosis- familial intestinal

Intestinal neurofibromatosis is an alternate form of neurofibromatosis. Patients present with neurofibromas limited to the intestine in the absence of any other typical features of NF1 and NF2

Neurofibromatosis- type 4- of Riccardi

Neurofibromatosis, type 4, of Riccardi: A rare genetic disorder characterized by areas of increased and decreased skin pigmentation and the development of many non-cancerous nerve and skin tumors some of which may eventually become malignant.

Neurofibromatosis-Noonan syndrome

Neurofibromatosis-Noonan syndrome: A rare disorder where the patients has symptoms of neurofibromatosis (nerve tumors) and Noonan syndrome (short stature, bleeding problems, heart defect, unusual facial features, skeletal anomalies, webbed neck).

Neurofibrosarcoma

Neurofibrosarcoma, is a form of cancer of the connective tissue surrounding nerves. Given its origin and behavior it is classified as a sarcoma. About half the cases are diagnosed in people with neurofibromatosis; the lifetime risk for an MPNST in patients with neurofibromatosis type 1 is 8-13%. MPNST with rhabdomyoblastomatous component are called malignant triton tumors.

Neurogenic hypertension

Neurogenic hypertension is listed as a "rare disease" by the Office of Rare Diseases (ORD) of the National Institutes of Health (NIH). This means that Neurogenic hypertension, or a subtype of Neurogenic hypertension, affects less than 200,000 people in the US population. Source - National Institutes of Health (NIH)

Neuroleptic malignant syndrome

Neuroleptic malignant syndrome (NMS) is a life-threatening neurological disorder most often caused by an adverse reaction to neuroleptic or antipsychotic drugs. It generally presents with muscle rigidity, fever, autonomic instability and cognitive changes such as delirium, and is proven on a raised creatine phosphokinase (CPK). Treatment is generally supportive.

Neuroma biliary tract

Neuroma biliary tract: A benign nerve tumor that occurs in the biliary tract. Often occurs after certain surgeries such as gall bladder removal.

Neuromyelitis optica

Neuromyelitis optica (NMO, also known as Devic's disease or Devic's syndrome), is a heterogeneous condition consisting of the simultaneous inflammation and demyelination of the optic nerve (optic neuritis) and the spinal cord (myelitis). It can be monophasic or recurrent.

Currently at least two different causes are proposed based on the presence of autoantibodies against AQP4. AQP4+ NMO is currently considered an autoimmune disease (autoimmune astrocytopathy, or autoimmune astrocytic channelopathy) in which a person's own immune system attacks the astrocytes of the optic nerves and spinal cord. The cause of the AQP4- variants is unknown.

Although inflammation may also affect the brain, the lesions are different from those observed in the related condition, multiple sclerosis. Spinal cord lesions lead to varying degrees of weakness or paralysis in the legs or arms, loss of sensation (including blindness), and/or bladder and bowel dysfunction.

Devic's disease is now studied along a collection of similar diseases called "Neuromyelitis optica spectrum diseases". Some cases of this spectrum resemble multiple sclerosis (MS) in several ways, but require a different course of treatment for optimal results.

In 2004, NMO-IgG (currently known as Anti-AQP IgG) was first described leading to the distinction between positive and negative cases.

In Anti-AQP positive variants, CNS astrocytes, which are the basis for the glymphatic system are the target of the autoimmune attack. NMO-IgG-negative cases are less understood. It seems currently that astrocytes are spared in these IgG negative cases.

Neuronal intestinal pseudoobstruction

Intestinal pseudoobstruction is the decreased ability of the intestines to push food through, and often causes dilation of various parts of the bowel. It can be a primary condition (idiopathic or inherited from a parent) or caused by another disease (secondary). The clinical and radiological findings are often similar to true intestinal obstruction.

Neuronal intranuclear hyaline inclusion disease

Neuronal intranuclear hyaline inclusion disease: A very rare syndrome characterized mainly by muscle problems and seizures . The disorder results from the presence of hyaline compounds inside nerve cells.

Neuropathy ataxia and retinis pigmentosa

Neuropathy ataxia and retinis pigmentosa: A rare inherited disorder where defects in the energy producing part of cells affects the nervous system and causes symptoms such as muscle and vision problems. Severity and rang of symptoms are variable.

Neuropathy hereditary sensory and autonomic type 1

Type 1 is the most common of the hereditary sensory and autonomic neuropathies (HSAN). Current names are: hereditary sensory neuropathy type I (HSN I), hereditary sensory and autonomic neuropathy type I (HSAN I).[3] Historical names include: Hereditary sensory radicular neuropathy, ulcero-mutilating neuropathy, thevenard syndrome, familial trophoneurosis, mal perforant du pied, and familial syringomyelia.[3] Sub-type 1C is also currently known as Charcot-Marie-Tooth type 2B syndrome (HMSN 2B).[3] Type 1 is transmitted as autosomal dominant trait and is characterized by a sensory deficit in the distal portion of the lower extremities, chronic perforating ulcerations of the feet and progressive destruction of underlying bones. Symptoms appear in late childhood on early adolescence with trophic ulcers as pain sensation is affected more. Many patients have accompanying nerve deafness and atrophy of the peroneal muscles. Histopathologic examination reveals a marked reduction in the number of unmyelinated fibers. Motor nerve conduction velocities are normal, but the sensory nerve action potentials are absent.

Neuropathy motor sensory type 2 deafness mental retardation

Neuropathy motor sensory type 2 deafness mental retardation: An inherited neurological disease characterized by the gradual degeneration of nerves which starts in the hands and feet and results in progressive numbness, muscle weakness and loss of function. Deafness and mental retardation are also involved

Neuropathy sensory spastic paraplegia

A very rare syndrome characterized mainly by sensory nerve degeneration and spastic paraplegia. The extremities of the hands and feet have reduced pain sensation and disfiguring ulcers tend to develop.

Neuropathy- hereditary motor and sensory- LOM type

Neuropathy, hereditary motor and sensory, LOM type: A severe form of Charcot-Marie-Tooth disease which involves the loss of the protective covering around nerves resulting in various nerve problems. Muscle weakness and wasting and sensory loss is more severe in the ends of the arms and legs.

Neuropathy- hereditary motor and sensory- Okinawa type

Neuropathy, hereditary motor and sensory, Okinawa type: A dominantly inherited, slow-progressing motor and sensory nerve disease which primarily involves the proximal muscles (i.e. the muscles closest to the trunk of the body).

Neuropathy- hereditary motor and sensory- Russe type

CMT is an inherited neurological disease characterized by the gradual degeneration of nerves which starts in the hands and feet and results in progressive numbness, muscle weakness and loss of function. Type 4G has an autosomal recessive form of inheritance and is a severe form of the disease. It involves a defect on Chromosome 10.

Neurosarcoidosis

Sarcoidosis is a multisystem disease process whose pathogenesis involves formation of an inflammatory lesion known as a granuloma. Most patients with sarcoidosis do not have any symptoms; the disease often is detected on routine chest radiograph. Symptoms, if present, include cough, shortness of breath, and arthritis. The lungs are affected most frequently, but the eyes, nervous system, heart, kidneys, bones, and joints also may be affected. Sarcoidosis is a disease of unknown etiology. Involvement of the central nervous system is referred to as neurosarcoidosis. Neurosarcoidosis is an uncommon but severe, sometimes life-threatening, manifestation of sarcoidosis. It generally occurs only if the disease has had substantial systemic involvement, and signs of neurologic involvement usually are seen in patients known to have active disease. Strictly neurologic forms are seen in fewer than 10% of patients.

Neurosyphilis

Syphilis bacteria frequently invade the nervous system during the early stages of infection, and approximately 3 to 7 percent of persons with untreated syphilis develop neurosyphilis. Some persons with neurosyphilis never develop any symptoms. Others may have headache, stiff neck, and fever that result from an inflammation of the lining of the brain. Some patients develop seizures. Patients whose blood vessels are affected may develop symptoms of stroke with resulting numbness, weakness, or visual complaints. In some instances, the time from infection to developing neurosyphilis may be up to 20 years. Neurosyphilis may be more difficult to treat and its course may be different in people with HIV infection

Neurotoxicity syndromes

Neurotoxicity syndromes: Altered nervous system functioning caused by exposure to certain chemicals (manmade or natural) that affect the nervous system - essentially it is the poisoning of the nervous system. Examples of toxic compounds that may cause neurotoxicity include lead, certain solvents and pesticides. Symptoms may occur immediately or gradually over a period of time. Neurotoxicity syndromes is listed as a "rare disease" by the Office of Rare Diseases (ORD) of the National Institutes of Health (NIH). This means that Neurotoxicity syndromes, or a subtype of Neurotoxicity syndromes, affects less than 200,000 people in the US population.

Neurotrophic Keratopathy

Neurotrophic keratopathy is a degenerative disease of the corneal epithelium resulting from impaired corneal innervation. A reduction in corneal sensitivity or complete corneal anesthesia is the hallmark of this disease and is responsible for producing epithelial keratopathy, ulceration and perforation. Although numerous ocular and systemic diseases may result in neurotrophic keratopathy, there is one common insult: a lesion of the trigeminal nerve (cranial nerve V) or its branches.

Patients with neurotrophic keratopathy should undergo a complete medical and surgical history, a review of medications and an ocular examination. Although the clinical diagnosis may be made without difficulty, the management of neurotrophic keratopathy can be quite challenging.

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