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 and nerve disorders in the following overlapping categories:

- Brain:

- Brain damage according to cerebral lobe "(see also 'lower' brain areas such as basal ganglia, cerebellum, brainstem)":

- Frontal lobe damage

- Parietal lobe damage

- Temporal lobe damage

- Occipital lobe damage

- Brain dysfunction according to type:

- Aphasia (language)

- Dysgraphia (writing)

- Dysarthria (speech)

- Apraxia (patterns or sequences of movements)

- Agnosia (identifying things or people)

- Amnesia (memory)

- Spinal cord disorders (see spinal pathology, injury, inflammation)

- Peripheral neuropathy and other Peripheral nervous system disorders

- Cranial nerve disorder such as Trigeminal neuralgia

- Autonomic nervous system disorders such as dysautonomia, Multiple System Atrophy

- Seizure disorders such as epilepsy

- Movement disorders of the central and peripheral nervous system such as Parkinson's disease, Essential tremor, Amyotrophic lateral sclerosis, Tourette's Syndrome, Multiple Sclerosis and various types of Peripheral Neuropathy

- Sleep disorders such as Narcolepsy

- Migraines and other types of Headache such as Cluster Headache and Tension Headache

- Lower back and neck pain (see Back pain)

- Central neuropathy (see Neuropathic pain)

- Neuropsychiatric illnesses (diseases and/or disorders with psychiatric features associated with known nervous system injury, underdevelopment, biochemical, anatomical, or electrical malfunction, and/or disease pathology e.g. Attention deficit hyperactivity disorder, Autism, Tourette's syndrome and some cases of obsessive compulsive disorder as well as the neurobehavioral associated symptoms of degeneratives of the nervous system such as Parkinson's disease, essential tremor, Huntington's disease, Alzheimer's disease, multiple sclerosis and organic psychosis.)

Many of the diseases and disorders listed above have neurosurgical treatments available (e.g. Tourette's Syndrome, Parkinson's disease, Essential tremor and Obsessive compulsive disorder).

- Delirium and dementia such as Alzheimer's disease

- Dizziness and vertigo

- Stupor and coma

- Head injury

- Stroke (CVA, cerebrovascular attack)

- Tumors of the nervous system (e.g. cancer)

- Multiple sclerosis and other demyelinating diseases

- Infections of the brain or spinal cord (including meningitis)

- Prion diseases (a type of infectious agent)

- Complex regional pain syndrome (a chronic pain condition)

Neurological disorders in non-human animals are treated by veterinarians.

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 and altered levels of consciousness. There are many recognized neurological disorders, some relatively common, but many rare. They may be assessed by neurological examination, and studied and treated within the specialities of neurology and clinical neuropsychology.

Interventions for neurological disorders include preventative measures, lifestyle changes, physiotherapy or other therapy, neurorehabilitation, pain management, medication, or operations performed by neurosurgeons. 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 suffering.

Reported neurological symptoms include difficulty sleeping, decrease in intellectual capacity, dizziness, altered visual perceptive abilities, affected psychomotor skills, forgetfulness, and disorientation. The mechanism behind these symptoms beyond solvent molecules crossing the blood-brain barrier is currently unknown. Neurological signs include impaired vibratory sensation at extremities and an inability to maintain steady motion, a possible effect from psychomotor damage in the brain. Other symptoms that have been seen range from fatigue, decreased strength, and unusual gait. One study found that there was a correlation between decreased red blood cell count and level of solvent exposure, but not enough data has been found to support any blood tests to screen for CSE.

Two characteristic symptoms of CSE are deterioration of memory (particularly short-term memory), and attention impairments. There are, however, numerous other symptoms that accompany to varying degrees. Variability in the research methods studying CSE makes characterizing these symptoms difficult, and some may be questionable regarding whether they are actual symptoms of solvent-induced syndromes, simply due to how infrequently they appear. Characterizing of CSE symptoms is more difficult because CSE is currently poorly defined, and the mechanism behind it is not understood yet.

Tangentiality as a medical symptom is a physical symptom observed in speech that tends to occur in situations where a person is experiencing high anxiety, as a manifestation of the psychosis known as "schizophrenia", in dementia or in states of delirium.

The variable presentation of ROHHAD includes the following main symptoms:

- Hyperphagia and obesity by age of 10 years - (median age 3 years);

- Respiratory Manifestations:

- Alveolar Hypoventilation (median onset age 6.2 years);

- Cardiorespiratory arrest;

- Reduced Carbon Dioxide Ventilatory Response;

- Obstructive sleep apnea.

- Thermal or other hypothalamic dysregulations, with autonomic dysregulation by median age 3.6 years:

- Failed Growth Hormone Stimulation;

- Adipsic hypernatremia (inability to feel thirst to keep normal hydration);

- Hypernatremia;

- Hyperprolactinemia;

- Hyperphagia;

- Diabetes insipidus;

- Ophthalmologic Manifestations;

- Thermal Dysregulation;

- Gastrointestinal dysmotility;

- Altered Perception of Pain;

- Altered Sweating;

- Cold Hands and Feet.

- Neurobehavioral disorders;

- Tumors of neural crest origin.

Clinically overlapping cases exist because CCHS phenotype can also include autonomic nervous system dysregulation, or tumors of neural crest origin.

Bhaskar–Jagannathan syndrome is an extremely rare genetic disorder and there is a limited amount of information related to it. Similar or related medical conditions are arachnodactyly, aminoaciduria, congenital cataracts, cerebellar ataxia, and delayed developmental milestones.

Bhaskar–Jagannathan has symptoms such as long fingers, thin fingers, poor balance, incoordination, high levels of amino acids in urine, cataracts during infancy, and ataxia. Ataxia, which is a neurological sign and symptom made up of gross incoordination of muscle movements and is a specific clinical manifestation

Rapid-onset Obesity with Hypothalamic dysfunction, Hypoventilation and Autonomic Dysregulation (ROHHAD syndrome) is a very rare disease affecting approximately 75 people worldwide. Patients with ROHHAD, as well as patients with congenital central hypoventilation syndrome (CCHS) have damage to the mechanism governing proper breathing. ROHHAD syndrome is a disease that is potentially lethal and incurable. Fifteen patients with ROHHAD were evaluated by Diego Ize-Ludlow et al. work published in 2007.

The term refers simplistically to a thought disorder shown from speech with a lack of observance to the main subject of discourse, such that a person whilst speaking on a topic deviates from the topic. Further definition is of speech that deviates from an answer to a question that is relevant in the first instance but deviates from the relevancy to related subjects not involved in a direct answering of the question. In the context of a conversation or discussion the communication is a response that is ineffective in that the form is inappropriate for adequate understanding. The person's speech seems to indicate that their attention to their own speech has perhaps in some way been overcome during the occurrence of cognition whilst speaking, causing the vocalized content to follow thought that is apparently without reference to the original idea or question; or the person's speech is considered evasive in that the person has decided to provide an answer to a question that is an avoidance of a direct answer.

Movement disorders are clinical syndromes with either an excess of movement or a paucity of voluntary and involuntary movements, unrelated to weakness or spasticity. Movement disorders are synonymous with basal ganglia or extrapyramidal diseases. Movement disorders are conventionally divided into two major categories- "hyperkinetic" and "hypokinetic".

Hyperkinetic movement disorders refer to dyskinesia, or excessive, often repetitive, involuntary movements that intrude upon the normal flow of motor activity.

Hypokinetic movement disorders refer to akinesia (lack of movement), hypokinesia (reduced amplitude of movements), bradykinesia (slow movement) and rigidity. In primary movement disorders, the abnormal movement is the primary manifestation of the disorder. In secondary movement disorders, the abnormal movement is a manifestation of another systemic or neurological disorder.

Panayiotopoulos syndrome occurs exclusively in otherwise normal children and manifests mainly with infrequent autonomic epileptic seizures and autonomic status epilepticus. Onset of seizures is from age 1 to 14 years with 76% starting between 3–6 years. Autonomic seizures consist of episodes of disturbed autonomic function with nausea, retching and vomiting as predominant symptoms. Other autonomic manifestations include pallor (or, less often, flushing or cyanosis), mydriasis (or, less often, miosis), cardiorespiratory and thermoregulatory alterations, incontinence of urine and/or feces, hypersalivation, and modifications of intestinal motility. In approximately one fifth of the seizures the child becomes unresponsive and flaccid (syncope-like epileptic seizures or ictal syncope) before or often without convulsions. Syncope-like epileptic seizures (ictal syncope) with the child becoming "completely unresponsive and flaccid like a rag doll" occur in one fifth of the seizures. More-conventional seizure symptoms often appear after the onset of autonomic manifestations. The child, who was initially fully conscious, becomes confused and unresponsive. Eyes turn to one side or gaze widely open. Only half of the seizures end with brief hemiconvulsions or generalized convulsions. Autonomic symptoms may be the only features of the seizures. None of the above symptoms alone is a prerequisite for diagnosis. Recurrent seizures may not be stereotyped. The same child may have brief or prolonged seizures and autonomic manifestations may be severe or inconspicuous. The full emetic triad (nausea, retching, vomiting) culminates in vomiting in 74% of the seizures; in others only nausea or retching occur, and in a few, none of the emetic symptoms are apparent.

Most of the seizures are prolonged and half of them last more than 30 minutes thus constituting autonomic status epilepticus, which is the more common nonconvulsive status epilepticus in normal children. Characteristically, even after the most severe seizures and autonomic status epilepticus, the child is normal after a few hours of sleep, which is both diagnostic and reassuring. However, it has been recently reported that sometime after status epilepticus in children with Panayiotopoulos syndrome a. growth of the frontal and prefrontal lobes is slightly decreased and b.the scores on the neuropsychological tests is decreased.

Focal onset hemiconvulsions or generalised convulsions occur in nearly half of the seizures. These are usually shorter than the preceding autonomic manifestations but in a few cases a. they may be prolonged constituting convulsive status epilepticus or b. the preceding autonomic manifestations are brief and not apparent

Seizures can occur at any time but they are more common during sleep.

Panayiotopoulos syndrome (named after C. P. Panayiotopoulos) is a common idiopathic childhood-related seizure disorder that occurs exclusively in otherwise normal children (idiopathic epilepsy) and manifests mainly with autonomic epileptic seizures and autonomic status epilepticus. An expert consensus has defined Panayiotopoulos syndrome as "a benign age-related focal seizure disorder occurring in early and mid-childhood. It is characterized by seizures, often prolonged, with predominantly autonomic symptoms, and by an EEG [electroencephalogram] that shows shifting and/or multiple foci, often with occipital predominance."

In psychiatry, thought broadcasting is the belief that others can hear or are aware of an individual's thoughts. This differs from telepathy in that the thoughts being broadcast are thought to be available to anybody.

Thought broadcasting can be a positive symptom of schizophrenia. Thought broadcasting has been suggested as one of the first rank symptoms (Schneider's first-rank symptoms) believed to distinguish schizophrenia from other psychotic disorders.

In mild manifestations, a person with this thought disorder may doubt their perception of thought broadcasting. When thought broadcasting occurs on a regular basis, the disorder can affect behavior and interfere with the person's ability to function in society. According to an individual's personality this is considered to be a severe manifestation of thought broadcasting that is usually indicative of schizophrenia.

Step I : Decide the dominant type of movement disorder

Step II : Make differential diagnosis of the particular disorder

Step II: Confirm the diagnosis by lab tests

- Metabolic screening

- Microbiology

- Immunology

- CSF examination

- Genetics

- Imaging

- Neurophysiological tests

- Pharmacological tests

In psychiatry, derailment (also loosening of association, asyndesis, asyndetic thinking, knight's move thinking, or entgleisen) is a thought disorder characterized by discourse consisting of a sequence of unrelated or only remotely related ideas. The frame of reference often changes from one sentence to the next.

In a mild manifestation, this thought disorder is characterized by slippage of ideas further and further from the point of a discussion. Derailment can often be manifestly caused by intense emotions such as euphoria or hysteria. Some of the synonyms given above ("loosening of association", "asyndetic thinking") are used by some authors to refer just to a "loss of goal": discourse that sets off on a particular idea, wanders off and never returns to it. A related term is tangentiality—it refers to off-the-point, oblique or irrelevant answers given to questions. In some studies on creativity, "knight's move thinking", while it describes a similarly loose association of ideas, is not considered a mental disorder or the hallmark of one; it is sometimes used as a synonym for lateral thinking.

The combination of muscular hypotonia and fixed dilated pupils in infancy is suspicious of Gillespie syndrome. Early onset partial aniridia, cerebellar ataxia, and mental retardation are hallmark of syndrome. The iris abnormality is specific and seems pathognomonic of Gillespie syndrome. The aniridia consisting of a superior coloboma and inferior iris hypoplasia, foveomacular dysplasia.

Atypical Gillespie syndrome associated with bilateral ptosis, exotropia, correctopia, iris hypoplasia, anterior capsular lens opacities, foveal hypoplasia, retinal vascular tortuosity, and retinal hypopigmentation.

Neurological signs ar nystagmus, mild craniofacial asymmetry, axial hypotonia, developmental delay, and mild mental retardation. Mariën P did not support the prevailing view of a global mental retardation as a cardinal feature of Gillespie syndrome but primarily reflect cerebellar induced neurobehavioral dysfunctions following disruption of the cerebrocerebellar anatomical circuitry that closely resembles the "cerebellar cognitive and affective syndrome" (CeCAS).

Congenital pulmonary stenosis and helix dysplasia can be associated.

Da Costa's syndrome is generally considered a physical manifestation of an anxiety disorder.

Gillespie syndrome, also called aniridia, cerebellar ataxia and mental deficiency. is a rare genetic disorder. The disorder is characterized by partial aniridia (meaning that part of the iris is missing), ataxia (motor and coordination problems), and, in most cases, intellectual disability. It is heterogeneous, inherited in either an autosomal dominant or autosomal recessive manner. Gillespie syndrome was first described by American ophthalmologist Fredrick Gillespie in 1965.

Individuals affected by AAA have adrenal insufficiency/Addison's disease due to ACTH resistance, alacrima (absence of tear secretion), and achalasia (a failure of a ring of muscle fibers, such as a sphincter, to relax) of the lower esophageal sphincter at the cardia which delays food going to the stomach and causes dilation of the thoracic esophagus. There may also be signs of autonomic dysfunction with AAA, such as pupillary abnormalities, an abnormal reaction to intradermal histamine, abnormal sweating, orthostatic hypotension, and disturbances of the heart rate. Hypoglycemia (low blood sugar) is often mentioned as an early sign. The disorder has also been associated with mild mental retardation.

The syndrome is highly variable. Managed effectively, affected individuals can have a normal lifespan and bear children.

Symptoms may last for days, weeks, or months until the injury is healed. The most apparent sign of hypermetabolism is an abnormally high intake of calories followed by continuous weight loss. Internal symptoms of hypermetabolism include but are not limited to: peripheral insulin resistance, elevated catabolism of protein, carbohydrates and triglycerides, and a negative nitrogen balance in the body.

Outward symptoms of hypermetabolism may include:

- Sudden weight loss

- Anemia

- Fatigue

- Elevated heart rate

- Irregular heartbeat

- Insomnia

- Dysautonomia

- Shortness of breath

- Muscle weakness

- Excessive sweating

Symptoms of Da Costa's syndrome include fatigue upon exertion, shortness of breath, palpitations, sweating, and chest pain. Physical examination reveals no physical abnormalities causing the symptoms.

Positron emission tomography (PET scan) is the primary means of detection for hyperthyroidism. This technique identifies both the location and the cause of hypermetabolic activity within the body. The resolution of PET scans, however, are limited and inconsistent in detecting the details of cortical alterations.

Chorea can also be a manifestation of drug toxicity (for example, anticonvulsants, antiparkinson agents, neuroleptics, steroids, and estrogen), or a result of an infectious disease such as meningovascular syphilis, Lyme disease, viral encephalitis, and many others.

Triple-A syndrome or AAA syndrome, also known as achalasia-addisonianism-alacrima syndrome or Allgrove syndrome, is a rare autosomal recessive congenital disorder. In most cases, there is no family history of it. The syndrome was first identified by Jeremy Allgrove and colleagues in 1978. The syndrome involves achalasia, addisonianism (adrenal insufficiency of primary type), and alacrima (insufficiency of tears). Alacrima is usually the earliest manifestation. It is a progressive disorder that can take years to develop the full blown clinical picture.