A neurological disorder is any disorder of the nervous system. Structural, biochemical or electrical abnormalities in the brain, spinal cord, or other nerves can result in a range of symptoms. Examples of symptoms include paralysis, muscle weakness, poor coordination, loss of sensation, seizures, confusion, pain, tauopathies, and altered levels of consciousness. There are many recognized neurological disorders; some are relatively common, but many are rare. Interventions for neurological disorders include preventive measures, lifestyle changes, physiotherapy or other therapy, neurorehabilitation, pain management, medication, operations performed by neurosurgeons, or a specific diet. The World Health Organization estimated in 2006 that neurological disorders and their sequelae (direct consequences) affect as many as one billion people worldwide and identified health inequalities and social stigma/discrimination as major factors contributing to the associated disability and their impact.
Causes Although the brain and spinal cord are surrounded by tough membranes, enclosed in the bones of the skull and spinal vertebrae, and chemically protected by the blood-brain barrier, they are very susceptible if compromised. Nerves tend to lie deep under the skin but can still become exposed to damage. Individual neurons, the neural circuits, and the nerves into which they form are susceptible to electrochemical and structural disruption. Neuroregeneration may occur in the peripheral nervous system and thus overcome or work around injuries to some extent, but it is thought to be rare in the brain and spinal cord. The specific causes of neurological problems vary but can include genetic disorders, congenital abnormalities or disorders, infections, lifestyle and environmental health problems such as malnutrition and pollution, brain damage, spinal cord injury, nerve injury, and gluten sensitivity (with or without intestinal damage or digestive symptoms). Metal poisoning, where metals accumulate in the human body and disrupt biological processes, has been reported to induce neurological problems, at least in the case of lead. The neurological problem may start in another body system that interacts with the nervous system. For example, cerebrovascular disease involves brain injury due to problems with the blood vessels (cardiovascular system) supplying the brain; autoimmune disorders involve damage caused by the body's own immune system; lysosomal storage diseases such as Niemann–Pick disease can lead to neurological deterioration. The National Institute for Health and Care Excellence recommends considering the evaluation of underlying coeliac disease in people with unexplained neurological symptoms, particularly peripheral neuropathy or ataxia. In a substantial minority of cases of neurological symptoms, no neurological cause can be identified using current testing procedures, and such "idiopathic" conditions can invite different theories about what is occurring. Generally speaking, a substantial number of neurological disorders may have originated from a previous clinically not recognized viral infection. For example, it is thought that infection with the Hepatitis E virus, which is often initially asymptomatic may provoke neurological disorders, but there are many other examples as well. Numerous examples have been described of neurological disorders that are associated with mutated DNA repair genes (for reviews see). Inadequate repair of DNA damages can lead directly to cell death and neuron depletion as well as disruptions in the pattern of epigenetic alterations required for normal neuronal function.
DNA damage Neurons are highly oxygenated cells and as a consequence DNA damage caused by chronic exposure to endogenous reactive oxygen species is a substantial challenge for neurons. Germline mutations deficient in the repair of DNA damages cause neuronal dysfunction and are etiologically linked to many neurological disorders. For example, the neurological disorders, amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are linked to DNA damage accumulation and DNA repair deficiency.
Classification
Neurological disorders can be categorized according to the primary location affected, the primary type of dysfunction involved, or the primary type of cause. The broadest division is between central nervous system disorders and peripheral nervous system disorders. The Merck Manual lists brain, spinal cord disorders, and nerve disorders in the following overlapping categories:
Brain: Brain dysfunction according to type: Apraxia (patterns or sequences of movements) Agnosia (identifying things or people) Amnesia (memory) Aphasia (language) Dysarthria (speech) Spinal cord disorders Peripheral nervous system disorders (e.g., Peripheral neuropathy) Cranial nerve disorder (e.g., trigeminal neuralgia) Autonomic nervous system disorders (e.g., dysautonomia, multiple system atrophy) Epilepsy Movement disorders of the central and peripheral nervous system such as Parkinson's disease, essential tremor, amyotrophic lateral sclerosis (ALS), and Tourette syndrome Sleep disorders (e.g., narcolepsy) Some speech disorders (e.g., stuttering) Headaches (e.g., migraine, cluster headache, tension headache) Pain (e.g., complex regional pain syndrome, fibromyalgia) Delirium Dementia (e.g., Alzheimer's disease) Coma and impaired consciousness, (e.g., stupor) Stroke Tumors of the nervous system (e.g., cancer) Multiple sclerosis and other demyelinating diseases Brain infections Meningitis Prion diseases (a type of infectious agent) Neurological disorders in non-human animals are treated by veterinarians.
… excerpt ends here. Continue reading the full article.
